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Sample records for cerebral tissue oxygenation

  1. Real-time changes in brain tissue oxygen during endovascular treatment of cerebral vasospasm

    DEFF Research Database (Denmark)

    Rasmussen, Rune; Bache, Søren; Stavngaard, Trine;

    2015-01-01

    pressure (PtiO₂) in target parenchyma. However, during the intervention, dangerously low levels of brain tissue oxygen, leading to cerebral infarction, may occur. Thus, no clinical improvement was seen in two of the patients and a dramatic worsening was observed in the third patient. Because the decrease...... minute-by-minute changes in brain tissue oxygen during balloon angioplasty and intraarterial administration of vasodilators in three patients.Our results confirm that endovascular intervention is capable of not only resolving angiographic vasospasm, but also of normalizing values of brain tissue oxygen...... in brain tissue oxygen was seen after administration of vasopressor agents, this may be a contributing factor....

  2. Studies of cerebral blood flow, cerebral oxygen metabolism, cerebral glucose metabolism, and tissue pH in human acute cerebral infarction using positron emission tomography

    International Nuclear Information System (INIS)

    This preliminary PET study was designed to investigate physiological and biochemical changes in acute cerebral infarction by positron emission tomography (PET). PET studies were performed in six patients with acute cerebral infarction within 48 hours after onset of stroke using continuous inhalation of C15O2 for cerebral blood flow (CBF), 15O2 for cerebral metabolic rate for oxygen (CMRO2), 11CO for cerebral blood volume, the intravenous injection of 11C-dimethyloxazolidinedione for tissue pH and the intravenous injection of 18F-fluorodeoxyglucose for cerebral metabolic rate for glucose (CMRGlu). Metabolic coupling index (MCI) image was made from CBF image and CMRGlu image to investigate relation between CBF and CMRGlu. Aslo oxygen glucose index (OGI) image was made from CMRO2 image and CMRG lu image to investigate relation between CMRO2 and CMRGlu. Preliminary resul ts demonstrate that reduction of CBF, CMRO2, and CMRGlu in the affected co rtex except for reperfusion case. Increase of OER was recognized four of six cases. Patterns of MCI and OGI in the cortex which CMRO2 value is less than 65 μmol/100g/min were different from those in the cortex which CMRO2 value is more than 65. MCI of the affected cortex (CMRO22>=65). OGI of the affected cortex (CMRO22>=65). Two patients showed decrease of tissue pH and reperfusion case showed increase of tissue pH in infarcted area as compared to contralateral cortex. In addition it was suggested that threshold of CBF for tissue pH was approximately 14ml/100g/min. (J.P.N.)

  3. Precision of measurement of cerebral tissue oxygenation index using near-infrared spectroscopy in preterm neonates

    DEFF Research Database (Denmark)

    Sorensen, Line C; Greisen, Gorm

    2006-01-01

    The use of cerebral tissue oxygenation index (c-TOI) in a clinical setting is limited by doubts concerning the accuracy of the measurements. Since there is no gold standard, validation is difficult. Our modest aim was to quantify the precision of c-TOI doing repeated measurements by reapplying the...

  4. The Effect on Cerebral Tissue Oxygenation Index of Changes in the Concentrations of Inspired Oxygen and End-Tidal Carbon Dioxide in Healthy Adult Volunteers

    OpenAIRE

    Tisdall, M. M.; C. Taylor; Tachtsidis, I.; Leung, T S; Elwell, C. E.; Smith, M

    2009-01-01

    BACKGROUND: A variety of near-infrared spectroscopy devices can be used to make noninvasive measurements of cerebral tissue oxygen saturation (ScO2). The ScO2 measured by the NIRO 300 spectrometer (Hamamatsu Photonics, Japan) is called the cerebral tissue oxygenation index (TOI) and is an assessment of the balance between cerebral oxygen delivery and utilization. We designed this study to investigate the effect of systemic and intracranial physiological changes on TOI.METHODS: Fifteen healthy...

  5. Cerebral oxygenation after birth

    DEFF Research Database (Denmark)

    Hessel, Trine W; Hyttel-Sorensen, Simon; Greisen, Gorm

    2014-01-01

    AIM: To compare absolute values of regional cerebral tissue oxygenation (cStO2 ) during haemodynamic transition after birth and repeatability during steady state for two commercial near-infrared spectroscopy (NIRS) devices. METHODS: In a prospective observational study, the INVOS 5100C and FORE...... INVOS and FORE-SIGHT cStO2 estimates showed oxygenation-level-dependent difference during birth transition. The better repeatability of FORE-SIGHT could be due to the lower response to change in saturation....

  6. Feasibility of long-term cerebral and peripheral regional tissue oxygen saturation measurements

    International Nuclear Information System (INIS)

    The aim of this study was to analyse the feasibility of long-term measurements of cerebral (crSO2) and peripheral (prSO2) regional tissue oxygen saturation on the first day of life by determining the amount of artefacts and their influence on rSO2. Near infrared spectroscopy (NIRS) measurements were performed fronto-parietal left (crSO2) and on the right forearm (prSO2). Arterial oxygen saturation (SpO2) was measured by pulse oximetry on the right wrist. Three criteria (C) were defined to identify artefacts (C1: missing values, C2: rSO2 jumping >15%, C3: rSO2 ≥ SpO2). The number of artefacts as a percentage of measurement time and mean rSO2 was calculated after the introduction of each criterion. Measurements were performed in 40 neonates. The number of artefacts in crSO2 measurements was similar after introduction of C1 (7.37 ± 4.64%) and after introduction of all criteria (8.89 ± 4.59%). The number of artefacts in prSO2 measurements after introduction of C1 was 10.83 ± 4.21%, and after introduction of all criteria significantly higher with 17.78 ± 4.27%. After introduction of C1, further criteria did not significantly change rSO2: crSO2 (78.6 ± 1.3% versus 78.5 ± 1.2%) and prSO2 (83.7 ± 0.9% versus 83.5 ± 0.9%). In conclusion, long-term NIRS measurements of crSO2 and prSO2 are feasible, since most artefacts are due to missing values and therefore easy to recognize. (paper)

  7. Cerebral tissue oxygenation index and superior vena cava blood flow in the very low birth weight infant.

    LENUS (Irish Health Repository)

    Moran, M

    2012-02-01

    BACKGROUND: Superior vena cava (SVC) flow assesses blood flow from the upper body, including the brain. Near infrared spectroscopy (NIRS) provides information on brain perfusion and oxygenation. AIM: To assess the relationship between cerebral tissue oxygenation index (cTOI) and cardiac output measures in the very low birth weight (VLBW) infant in the first day of life. METHODS: A prospective observational cohort study. Neonates with birth weight less than 1500 g (VLBW) were eligible for enrollment. Newborns with congenital heart disease, major congenital malformations and greater than Papile grade1 Intraventricular Haemorrhage on day 1 of life were excluded. Echocardiographic evaluation of SVC flow was performed in the first 24 h of life. Low SVC flow states were defined as a flow less than 40 mL\\/kg\\/min. cTOI was measured using NIRO 200 Hamamatsu. RESULTS: Twenty-seven VLBW neonates had both echocardiography and NIRS performed. The median (range) gestation was 29\\/40 (25 + 3 to 31 + 5 weeks) and median birth weight was 1.2 kg (0.57-1.48 kg). The mean (SD) TOI was 68.1 (7.9)%. The mean (SD) SVC flow was 70.36(39.5) mLs\\/kg\\/min. The correlation coefficient of cerebral tissue oxygenation and SVC flow was r = 0.53, p-value 0.005. There was a poor correlation between right and left ventricular output and cTOI which is not surprising considering the influence of intra- and extracardiac shunts. CONCLUSION: There is a positive relationship between cerebral TOI values and SVC flow in the very low birth infant on day one of life.

  8. Cerebral oxygenation and hyperthermia

    Directory of Open Access Journals (Sweden)

    AnthonyRichardBain

    2014-03-01

    Full Text Available Hyperthermia is associated with marked reductions in cerebral blood flow (CBF. Increased distribution of cardiac output to the periphery, increases in alveolar ventilation and resultant hypocapnia each contribute to the fall in CBF during passive hyperthermia; however, their relative contribution remains a point of contention, and probably depends on the experimental condition (e.g. posture and degree of hyperthermia. The hyperthermia-induced hyperventilatory response reduces arterial CO2 pressure (PaCO2 causing cerebral vasoconstriction and subsequent reductions in flow. During supine passive hyperthermia, the majority of recent data indicate that reductions in PaCO2 may be the primary, if not sole, culprit for reduced CBF. On the other hand, during more dynamic conditions (e.g. hemorrhage or orthostatic challenges, an inability to appropriately decrease peripheral vascular conductance presents a condition whereby adequate cerebral perfusion pressure may be compromised secondary to reductions in systemic blood pressure. Although studies have reported maintenance of pre-frontal cortex oxygenation (assessed by near-infrared spectroscopy during exercise and severe heat stress, the influence of cutaneous blood flow is known to contaminate this measure. This review discusses the governing mechanisms associated with changes in CBF and oxygenation during moderate to severe (i.e. 1.0°C to 2.0°C increase in body core temperature levels of hyperthermia. Future research directions are provided.

  9. Comparison Between Cerebral Tissue Oxygen Tension and Energy Metabolism in Experimental Subdural Hematoma

    DEFF Research Database (Denmark)

    Nielsen, Troels Halfeld; Engell, Susanne I; Johnsen, Rikke Aagaard;

    2011-01-01

    . Intracranial pressure (ICP) was monitored in the "good-side." RESULTS: ICP, cerebral perfusion pressure (CPP), PbtO(2), glucose, lactate, pyruvate, lactate-pyruvate ratio (LP ratio), glutamate, and glycerol were recorded at baseline (60 min) and post trauma (360 min). After the creation of the ASDH, PbtO(2...

  10. Effects of acetazolamide on cerebral blood flow and brain tissue oxygenation

    DEFF Research Database (Denmark)

    Lassen, N A; Friberg, L; Kastrup, J;

    1987-01-01

    Oral administration of 1 g of acetazolamide to 8 normal subjects studied at sea level and in normoxia caused an acute increase in cerebral blood flow (CBF). During the subsequent prolonged oral treatment with 1 g of acetazolamide daily, CBF returned to normal within 2 days. The alveolar CO2 tensi...

  11. The effects of different ventilator modes on cerebral tissue oxygen saturation in patients with bidirectional superior cavopulmonary connection

    Directory of Open Access Journals (Sweden)

    Ayda Türköz

    2014-01-01

    Full Text Available Aims and Objectives: We used near-infrared spectroscopy to document changes in cerebral tissue oxygen saturation (SctO 2 in response to ventilation mode alterations after bidirectional Glenn (BDG; superior cavopulmonary connection procedure. We also determined whether spontaneous ventilation have a beneficial effect on hemodynamic status, lactate and SctO 2 when compared with other ventilation modes. Materials and Methods: 20 consecutive patients undergoing BDG were included. We measured SctO 2 during three ventilator modes (intermittent positive-pressure ventilation [IPPV]; synchronized intermittent mandatory ventilation [SIMV]; and continuous positive airway pressure + pressure support ventilation [CPAP + PSV]. We, also, measured mean airway pressure (AWP, arterial blood gases, lactate and systolic arterial pressures (SAP. Results: There was no change in SctO 2 in IPPV and SIMV modes; the SctO 2 measured during CPAP + PSV and after extubation increased significantly (60.5 ± 11, 61 ± 10, 65 ± 10, 66 ± 11 respectively ( P < 0.05. The differences in the SAP measured during IPPV and SIMV modes was insignificant; the SAP increased significantly during CPAP + PSV mode and after extubation compared with IPPV and SIMV (109 ± 11, 110 ± 12, 95 ± 17, 99 ± 13 mmHg, respectively ( P < 0.05. Mean AWP did not change during IPPV and SIMV modes, mean AWP decreased significantly during CPAP + PSV mode (14 ± 4, 14 ± 3, 10 ± 1 mmHg, respectively ( P < 0.01. Conclusions: The SctO 2 was higher during CPAP + PSV ventilation and after extubation compared to IPPV and SIMV modes of ventilation. The mean AWP was lower during CPAP + PSV ventilation compared to IPPV and SIMV modes of ventilation.

  12. Measuring tissue oxygenation

    Science.gov (United States)

    Soyemi, Olusola O. (Inventor); Soller, Babs R. (Inventor); Yang, Ye (Inventor)

    2009-01-01

    Methods and systems for calculating tissue oxygenation, e.g., oxygen saturation, in a target tissue are disclosed. In some embodiments, the methods include: (a) directing incident radiation to a target tissue and determining reflectance spectra of the target tissue by measuring intensities of reflected radiation from the target tissue at a plurality of radiation wavelengths; (b) correcting the measured intensities of the reflectance spectra to reduce contributions thereto from skin and fat layers through which the incident radiation propagates; (c) determining oxygen saturation in the target tissue based on the corrected reflectance spectra; and (d) outputting the determined value of oxygen saturation.

  13. Analytic Models of Oxygen and Nutrient Diffusion, Metabolism Dynamics, and Architecture Optimization in Three-Dimensional Tissue Constructs with Applications and Insights in Cerebral Organoids.

    Science.gov (United States)

    McMurtrey, Richard J

    2016-03-01

    Diffusion models are important in tissue engineering as they enable an understanding of gas, nutrient, and signaling molecule delivery to cells in cell cultures and tissue constructs. As three-dimensional (3D) tissue constructs become larger, more intricate, and more clinically applicable, it will be essential to understand internal dynamics and signaling molecule concentrations throughout the tissue and whether cells are receiving appropriate nutrient delivery. Diffusion characteristics present a significant limitation in many engineered tissues, particularly for avascular tissues and for cells whose viability, differentiation, or function are affected by concentrations of oxygen and nutrients. This article seeks to provide novel analytic solutions for certain cases of steady-state and nonsteady-state diffusion and metabolism in basic 3D construct designs (planar, cylindrical, and spherical forms), solutions that would otherwise require mathematical approximations achieved through numerical methods. This model is applied to cerebral organoids, where it is shown that limitations in diffusion and organoid size can be partially overcome by localizing metabolically active cells to an outer layer in a sphere, a regionalization process that is known to occur through neuroglial precursor migration both in organoids and in early brain development. The given prototypical solutions include a review of metabolic information for many cell types and can be broadly applied to many forms of tissue constructs. This work enables researchers to model oxygen and nutrient delivery to cells, predict cell viability, study dynamics of mass transport in 3D tissue constructs, design constructs with improved diffusion capabilities, and accurately control molecular concentrations in tissue constructs that may be used in studying models of development and disease or for conditioning cells to enhance survival after insults like ischemia or implantation into the body, thereby providing a

  14. Cerebral and Muscle Tissue Oxygenation During Incremental Cycling in Male Adolescents Measured by Time-Resolved Near-Infrared Spectroscopy.

    Science.gov (United States)

    Ganesan, Goutham; Leu, Szu-Yun; Cerussi, Albert; Tromberg, Bruce; Cooper, Dan M; Galassetti, Pietro

    2016-05-01

    Near-infrared spectroscopy has long been used to measure tissue-specific O2 dynamics in exercise, but most published data have used continuous wave devices incapable of quantifying absolute Hemoglobin (Hb) concentrations. We used time-resolved near-infrared spectroscopy to study exercising muscle (Vastus Lateralis, VL) and prefrontal cortex (PFC) Hb oxygenation in 11 young males (15.3 ± 2.1 yrs) performing incremental cycling until exhaustion (peak VO2 = 42.7 ± 6.1 ml/min/kg, mean peak power = 181 ± 38 W). Time-resolved near-infrared spectroscopy measurements of reduced scattering (μs´) and absorption (μa) at three wavelengths (759, 796, and 833 nm) were used to calculate concentrations of oxyHb ([HbO2]), deoxy Hb ([HbR]), total Hb ([THb]), and O2 saturation (stO2). In PFC, significant increases were observed in both [HbO2] and [HbR] during intense exercise. PFC stO2% remained stable until 80% of total exercise time, then dropped (-2.95%, p = .0064). In VL, stO2% decreased until peak time (-6.8%, p = .01). Segmented linear regression identified thresholds for PFC [HbO2], [HbR], VL [THb]. There was a strong correlation between timing of second ventilatory threshold and decline in PFC [HbO2] (r = .84). These findings show that time-resolved near-infrared spectroscopy can be used to study physiological threshold phenomena in children during maximal exercise, providing insight into tissue specific hemodynamics and metabolism. PMID:26451845

  15. Improvement of Brain Tissue Oxygenation by Inhalation of Carbogen

    DEFF Research Database (Denmark)

    Ashkanian, M.; Borghammer, P.; Gjedde, A.; Ostergaard, L.; Vafaee, M.

    2008-01-01

    confirmed by statistical cluster analysis. Oxygen and carbogen were equally potent in increasing oxygen saturation of arterial blood (Sa(O2)). The present data demonstrate that inhalation of carbogen increases both CBF and Sa(O2) in healthy adults. In conclusion we speculate that carbogen inhalation is...... sufficient for optimal oxygenation of healthy brain tissue, whereas carbogen induces concomitant increases of CBF and Sa(O2).......Hyperoxic therapy for cerebral ischemia is suspected to reduce cerebral blood flow (CBF), due to the vasoconstrictive effect of oxygen on cerebral arterioles. We hypothesized that vasodilation predominates when 5% CO(2) is added to the inhaled oxygen (carbogen). Therefore, we used positron emission...

  16. Modelling cerebral blood oxygenation using Monte Carlo XYZ-PA

    Science.gov (United States)

    Zam, Azhar; Jacques, Steven L.; Alexandrov, Sergey; Li, Youzhi; Leahy, Martin J.

    2013-02-01

    Continuous monitoring of cerebral blood oxygenation is critically important for the management of many lifethreatening conditions. Non-invasive monitoring of cerebral blood oxygenation with a photoacoustic technique offers advantages over current invasive and non-invasive methods. We introduce a Monte Carlo XYZ-PA to model the energy deposition in 3D and the time-resolved pressures and velocity potential based on the energy absorbed by the biological tissue. This paper outlines the benefits of using Monte Carlo XYZ-PA for optimization of photoacoustic measurement and imaging. To the best of our knowledge this is the first fully integrated tool for photoacoustic modelling.

  17. Impact of Intraoperative Events on Cerebral Tissue Oximetry in Patients Undergoing Cardiopulmonary Bypass.

    Science.gov (United States)

    Ševerdija, Ervin E; Vranken, Nousjka P A; Teerenstra, Steven; Ganushchak, Yuri M; Weerwind, Patrick W

    2015-03-01

    Previous studies showed that decreased cerebral saturation during cardiac surgery is related to adverse postoperative outcome. Therefore, we investigated the influence of intraoperative events on cerebral tissue saturation in patients undergoing cardiac surgery with cardiopulmonary bypass (CPB). A total of 52 adult patients who underwent cardiac surgery using pulsatile CPB were included in this prospective explorative study. Cerebral tissue oxygen saturation (SctO2) was measured in both the left and right cerebral hemisphere. Intraoperative events, involving interventions performed by anesthesiologist, surgeon, and clinical perfusionist, were documented. Simultaneously, in-line hemodynamic parameters (partial oxygen pressure, partial carbon dioxide pressure, hematocrit, arterial blood pressure, and CPB flow rates) were recorded. Cerebral tissue saturation was affected by anesthetic induction (p partial oxygen pressures changed. Cerebral tissue oximetry effectively identifies changes related to surgical events or vulnerable periods during cardiac surgery. Future studies are needed to identify methods of mitigating periods of reduced cerebral saturation. PMID:26390677

  18. Oxygen Regulates Tissue Nitrite Metabolism

    OpenAIRE

    Curtis, Erin; Hsu, Lewis L.; Noguchi, Audrey C.; Geary, Lisa; Shiva, Sruti

    2012-01-01

    Aims: Once dismissed as an inert byproduct of nitric oxide (NO) auto-oxidation, nitrite (NO2-) is now accepted as an endocrine reservoir of NO that elicits biological responses in major organs. While it is known that tissue nitrite is derived from NO oxidation and the diet, little is known about how nitrite is metabolized by tissue, particularly at intermediate oxygen tensions. We investigated the rates and mechanisms of tissue nitrite metabolism over a range of oxygen concentrations. Results...

  19. PET Quantification of Cerebral Oxygen Metabolism in Small Animals

    OpenAIRE

    Takashi Temma; Kazuhiro Koshino; Tetsuaki Moriguchi; Jun-ichiro Enmi; Hidehiro Iida

    2014-01-01

    Understanding cerebral oxygen metabolism is of great importance in both clinical diagnosis and animal experiments because oxygen is a fundamental source of brain energy and supports brain functional activities. Since small animals such as rats are widely used to study various diseases including cerebral ischemia, cerebrovascular diseases, and neurodegenerative diseases, the development of a noninvasive in vivo measurement method of cerebral oxygen metabolic parameters such as oxygen extractio...

  20. Noninvasive optoacoustic monitoring of cerebral venous blood oxygenation in newborns

    Science.gov (United States)

    Petrov, Irene Y.; Wynne, Karon E.; Petrov, Yuriy; Esenaliev, Rinat O.; Richardson, C. Joan; Prough, Donald S.

    2012-02-01

    Cerebral ischemia after birth and during labor is a major cause of death and severe complications such as cerebral palsy. In the USA alone, cerebral palsy results in permanent disability of 10,000 newborns per year and approximately 500,000 of the total population. Currently, no technology is capable of direct monitoring of cerebral oxygenation in newborns. This study proposes the use of an optoacoustic technique for noninvasive cerebral ischemia monitoring by probing the superior sagittal sinus (SSS), a large central cerebral vein. We developed and built a multi-wavelength, near-infrared optoacoustic system suitable for noninvasive monitoring of cerebral ischemia in newborns with normal weight (NBW), low birth-weight (LBW, 1500 - 2499 g) and very low birth-weight (VLBW, neonatal intensive care unit. We performed single and continuous measurements of the SSS blood oxygenation. The data acquisition, processing and analysis software developed by our group provided real-time, absolute SSS blood oxygenation measurements. The SSS blood oxygenation ranged from 60% to 80%. Optoacoustic monitoring of the SSS blood oxygenation provides valuable information because adequate cerebral oxygenation would suggest that no therapy was necessary; conversely, evidence of cerebral ischemia would prompt therapy to increase cerebral blood flow.

  1. Inadequate cerebral oxygen delivery and central fatigue during strenuous exercise

    DEFF Research Database (Denmark)

    Nybo, Lars; Rasmussen, Peter

    2007-01-01

    Under resting conditions, the brain is protected against hypoxia because cerebral blood flow increases when the arterial oxygen tension becomes low. However, during strenuous exercise, hyperventilation lowers the arterial carbon dioxide tension and blunts the increase in cerebral blood flow, which...... can lead to an inadequate oxygen delivery to the brain and contribute to the development of fatigue....

  2. Propofol effect on cerebral oxygenation in children with congenital heart disease.

    Science.gov (United States)

    Fleck, Thilo; Schubert, Stephan; Ewert, Peter; Stiller, Brigitte; Nagdyman, Nicole; Berger, Felix

    2015-03-01

    Propofol is a short-acting, intravenously administered hypnotic agent which is used in procedural sedation in children. Propofol is known to decrease systemic vascular resistance, arterial blood pressure and can lead to desaturations and decreased systemic perfusion in children with cardiac shunting. This may result in a reduction in cerebral blood flow and oxygenation. Near-infrared spectroscopy (NIRS) can monitor cerebral tissue oxygenation in the frontal neocortex. The objective of our study was to measure the changes in cerebral oxygen and blood supply after Propofol infusion in children with congenital heart disease. Propofol infusion may reduce cerebral oxygenation in children with congenital heart disease. The study group consisted of 32 children (f:m = 18:14), with median age of 49 (5-112) months and median weight of 15 (5-34) kg. We performed NIRS derived continuous measurement of cerebral oxygenation and cardiac output using Electrical velocimetry for 5 min before and after sedation with Propofol (1-2 mg/kg i.v.) for cardiac catheterization. Simultaneously, non-invasive arterial blood pressure and transcutaneous oxygen saturation were measured. Propofol sedation led to a significant decrease in mean arterial pressure (79 ± 16 vs. 67 ± 12 mmHg) (p = 0.01) and cardiac index (3.2 ± 0.8 vs. 2.9 ± 0.6 ml/min/m(2)) (p = 0.03). In contrast, cerebral tissue oxygenation index, increased significantly from 57 ± 11 to 59 ± 10 % (p blood pressure. This may be caused by a decreased oxygen consumption of the sedated brain with intact cerebral auto-regulation. PMID:25311762

  3. Non-invasive measurement and validation of tissue oxygen saturation covered with overlying tissues

    Institute of Scientific and Technical Information of China (English)

    Yichao Teng; Haishu Ding; Lan Huang; Yue Li; Quanzhong Shan; Datian Ye; Haiyan Ding; Jenchung Chien; Betau Hwang

    2008-01-01

    In this paper,the biological tissue oxygen saturation(rS02)is obtained non-invasively and in real time based on near infrared spec-troscopy(NIRS)using two emitting wavelengths and two detectors,where the tissue is covered with overlying tissues.Our group devel-oped an NIRS oximeter based on the above principle independently,and validated it using liquid tissue model calibrations and animal experiments.The results indicate that(1)in the normal range of tissue oxygen saturation(40-70%),the rS02 measured by NIRS is accu-rate enough and little influenced by the background absorptions(such as the absorption of water)and overlying tissues(such as fat);(2)during cerebral hypoxia and recovery of three piglets,there is excellent correlation(p<0.001)between cerebral rS02 and jugular venous oxygen saturation(Sj02),meaning that the rS02 can be indicated by the Sj02 to a large extent;during the death of the three piglets induced by heart beat stopping,cerebral rS02 decreases continuously to significantly low levels(<25%)because cerebral blood supply does not exist any more.All the above results are of explicit physiological importance.

  4. Modeling of Cerebral Oxygen Transport Based on In vivo Microscopic Imaging of Microvascular Network Structure, Blood Flow, and Oxygenation

    Science.gov (United States)

    Gagnon, Louis; Smith, Amy F.; Boas, David A.; Devor, Anna; Secomb, Timothy W.; Sakadžić, Sava

    2016-01-01

    Oxygen is delivered to brain tissue by a dense network of microvessels, which actively control cerebral blood flow (CBF) through vasodilation and contraction in response to changing levels of neural activity. Understanding these network-level processes is immediately relevant for (1) interpretation of functional Magnetic Resonance Imaging (fMRI) signals, and (2) investigation of neurological diseases in which a deterioration of neurovascular and neuro-metabolic physiology contributes to motor and cognitive decline. Experimental data on the structure, flow and oxygen levels of microvascular networks are needed, together with theoretical methods to integrate this information and predict physiologically relevant properties that are not directly measurable. Recent progress in optical imaging technologies for high-resolution in vivo measurement of the cerebral microvascular architecture, blood flow, and oxygenation enables construction of detailed computational models of cerebral hemodynamics and oxygen transport based on realistic three-dimensional microvascular networks. In this article, we review state-of-the-art optical microscopy technologies for quantitative in vivo imaging of cerebral microvascular structure, blood flow and oxygenation, and theoretical methods that utilize such data to generate spatially resolved models for blood flow and oxygen transport. These “bottom-up” models are essential for the understanding of the processes governing brain oxygenation in normal and disease states and for eventual translation of the lessons learned from animal studies to humans.

  5. Acetazolamide improves cerebral oxygenation during exercise at high altitude

    NARCIS (Netherlands)

    Vuyk, J.; Bos, J. van den; Terhell, K.; Bos, R. de; Vletter, A.; Valk, P.; Beuzekom, M. van; Kleef, J. van; Dahan, A.

    2006-01-01

    Acute mountain sickness is thought to be triggered by cerebral hypoxemia and be prevented by acetazolamide (Actz). The effect of Actz on cerebral oxygenation at altitude remains unknown. In 16 members of the 2005 Dutch Cho Oyu (8201 m, Tibet) expedition, the influence of Actz and exercise (750 mg PO

  6. 脑氧饱和度监测在反屈氏位腹腔镜手术中的应用%Variation characteristics of cerebral tissue oxygen saturation in the reverse trendelenburg position during laparoscopic surgery

    Institute of Scientific and Technical Information of China (English)

    刘清海; 王天龙

    2014-01-01

    Objective To observe the variation characteristics of cerebral tissue oxygen saturation in the reverse (30°) Trendelenburg position during laparoscopic surgery.Methods Patients with gastric cancer undergoing laparoscopic surgery were monitored intraoperatively using the FORE-SIGHT cerebral oximeter.Two sensors were placed on the subject's forehead bilaterally for continuous monitoring of cerebral tissue oxygen saturation (SCTO2).The subjects were in the reverse Trendelenburg position during surgery.SCTO2,end-tidal carbon dioxide(PETCO2),mean arterial pressure (MAP) and Temperature were recorded every fifteen minutes after carbon dioxide pneumoperitoneum.Meanwhile,concentration of hemoglobin are examinated at preoperation and postoperation.All patients were followed up for neurological complications.Results 20 patients were monitored.The patients' age ranged from 34 to 80 years.The base value of SCTO2 was (72±6)% on the left sensor,and (72± 4)% on the right sensor.The SCTO2 maximum values were(84±5)% on the left sensor,and(81±4)% on the right sensor after 75 min carbon dioxide pneumoperitoneum.During pneumoperitoneum the SCTO2 values increased by (8±6)% on the left sensor,and (8±6)% on the right sensor.The maximum increasing amplitudes of SCTO2 were 15.49%(left) and 17.14%(right) respectively during CO2 pneumoperitoneum.The PETCO2 values before pneumoperitoneum,15 min and 75 min pneumoperitoneum were(33.8±2.3) mmHg,(38.4±2.8) mmHg and(40.8±2.2) mmHg,respectively.There were no significant difference in MAP,Temperature and hemoglobin concentration.Neurological complications of postoperation were not found.Conclusions The SCTO2 values increased under reverse trendelenburg and carbon dioxide pneumoperitoneum because of the raised FiO2 and cerebral blood flow due to hypercapnia which can contributed to maintain cerebral oxygen supply and demand balance.%目的 观察反屈氏位腹腔镜手术期间,患者无创局部脑氧饱和度(cerebral

  7. Increased intrathoracic pressure affects cerebral oxygenation following cardiac surgery

    DEFF Research Database (Denmark)

    Pedersen, Lars M; Nielsen, Jonas; Østergaard, Morten; Nygård, Eigil; Nielsen, Henning

    2012-01-01

    Cerebral oximetry reflects circulatory stability during surgery. We evaluated whether frontal lobe oxygenation is influenced by a transient increase in intrathoracic pressure as induced by a lung recruitment manoeuvre....

  8. MRI of brain tissue oxygen tension under hyperbaric conditions.

    Science.gov (United States)

    Muir, Eric R; Cardenas, Damon P; Duong, Timothy Q

    2016-06-01

    The brain depends on a continuous supply of oxygen to maintain its structural and functional integrity. This study measured T1 from MRI under normobaric air, normobaric oxygen, hyperbaric air, and hyperbaric oxygen (HBO) conditions as a marker of tissue pO2 since dissolved molecular oxygen acts as an endogenous contrast agent. Brain tissue T1 decreased corresponding to increased pO2 with increasing inhaled oxygen concentrations, and tissue oxygenation was estimated from the T1 changes between different inhaled oxygen levels. Tissue pO2 difference maps between different oxygen conditions showed heterogeneous pO2 changes in the brain. MRI-derived tissue pO2 was markedly lower than the arterial pO2 but was slightly higher than venous pO2. Additionally, for comparison with published extracellular tissue pO2 data obtained using oxygen electrodes and other invasive techniques, a model was used to estimate extracellular and intracellular pO2 from the MRI-derived mean tissue pO2. This required multiple assumptions, and so the effects of the assumptions and parameters used in modeling brain pO2 were evaluated. MRI-derived pO2 values were strongly dependent on assumptions about the extra- and intracellular compartments but were relatively less sensitive to variations in the relaxivity constant of oxygen and contribution from oxygen in the cerebral blood compartment. This approach may prove useful in evaluating tissue oxygenation in disease states such as stroke. PMID:27033683

  9. Cerebral oxygenation is reduced during hyperthermic exercise in humans

    DEFF Research Database (Denmark)

    Rasmussen, P.; Nybo, Lars; Volianitis, Stefanos; Møller, K.; Secher, N. H.; Gjedde, A.

    2010-01-01

    reduced by 15 +/- 13% (P < 0.05). During exercise with heat stress, RPE increased to 19 (19-20; P < 0.05); the RPE correlated inversely with P(mito)O(2) (r(2) = 0.42, P < 0.05). Conclusion: These data indicate that strenuous exercise in the heat lowers cerebral P(mito)O(2), and that exercise capacity in......Abstract Aim: Cerebral mitochondrial oxygen tension (P(mito)O(2)) is elevated during moderate exercise, while it is reduced when exercise becomes strenuous, reflecting an elevated cerebral metabolic rate for oxygen (CMRO(2)) combined with hyperventilation-induced attenuation of cerebral blood flow...... (CBF). Heat stress challenges exercise capacity as expressed by increased rating of perceived exertion (RPE). Methods: This study evaluated the effect of heat stress during exercise on P(mito)O(2) calculated based on a Kety-Schmidt-determined CBF and the arterial-to-jugular venous oxygen differences in...

  10. Measuring tissue oxygen saturation using NIR spectroscopy

    Science.gov (United States)

    Sircan-Kucuksayan, Aslinur; Uyuklu, Mehmet; Canpolat, Murat

    2014-05-01

    Tissue oxygen saturation (StO2) is known quite useful parameter for medical applications. A spectroscopic method has been developed to diagnose pathologic tissues due to lack of normal blood circulation by measuring tissue oxygen saturation. In the study, human blood samples with different level of oxygen saturations have been prepared and spectra were taken using an optical fiber probe to investigate correlation between the oxygen saturations and the spectra. The experimental set up for the spectroscopic measurements was consists of a miniature NIR light spectrometer, an optical fiber probe, a halogen-tungsten light source and a laptop. A linear correlation between the oxygen saturation of the blood samples and the ratio of the light of wavelengths 660 nm to 790 nm has been found from the spectra. Then, oxygen saturations of the blood samples were estimated from the spectroscopic measurements within an error of 2.9%. Furthermore, it has been shown that the linear dependence between the ratio and the oxygen saturation of the blood samples was valid for the blood samples with different hematocrits. Tissue oxygen saturation has been estimated from the spectroscopic measurements were taken from the fingers of healthy volunteers using the correlation between the spectra and blood oxygen saturation. The tissue StO2 measured was 80% as expected. The technique developed to measure tissue oxygen saturation has potential to diagnose premalignant tissues, follow up prognosis of cancerous tissues, and evaluation of ischemia reperfusion tissues.

  11. Oxygen Delivering Biomaterials for Tissue Engineering

    Science.gov (United States)

    Farris, Ashley L.; Rindone, Alexandra N.; Grayson, Warren L.

    2016-01-01

    Tissue engineering (TE) has provided promising strategies for regenerating tissue defects, but few TE approaches have been translated for clinical applications. One major barrier in TE is providing adequate oxygen supply to implanted tissue scaffolds, since oxygen diffusion from surrounding vasculature in vivo is limited to the periphery of the scaffolds. Moreover, oxygen is also an important signaling molecule for controlling stem cell differentiation within TE scaffolds. Various technologies have been developed to increase oxygen delivery in vivo and enhance the effectiveness of TE strategies. Such technologies include hyperbaric oxygen therapy, perfluorocarbon- and hemoglobin-based oxygen carriers, and oxygen-generating, peroxide-based materials. Here, we provide an overview of the underlying mechanisms and how these technologies have been utilized for in vivo TE applications. Emerging technologies and future prospects for oxygen delivery in TE are also discussed to evaluate the progress of this field towards clinical translation.

  12. Cerebral oxygen metabolism and cerebral blood flow in man during light sleep (stage 2)

    DEFF Research Database (Denmark)

    Madsen, P L; Schmidt, J F; Holm, S; Vorstrup, S; Lassen, N A; Wildschiødtz, Gordon

    We measured cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO2) during light sleep (stage 2) in 8 young healthy volunteers using the Kety-Schmidt technique with 133Xe as the inert gas. Measurements were performed during wakefulness and light sleep as verified by standard...... polysomnography. Unlike our previous study in man showing a highly significant 25% decrease in CMRO2 during deep sleep (stage 3-4) we found a modest but statistically significant decrease of 5% in CMRO2 during stage 2 sleep. Deep and light sleep are both characterized by an almost complete lack of mental activity....... They differ in respect of arousal threshold as a stronger stimulus is required to awaken a subject from deep sleep as compared to light sleep. Our results suggest that during non-rapid eye movement sleep cerebral metabolism and thereby cerebral synaptic activity is correlated to cerebral readiness...

  13. Maintained cerebral oxygenation during maximal self-paced exercise in elite Kenyan runners.

    Science.gov (United States)

    Santos-Concejero, J; Billaut, F; Grobler, L; Oliván, J; Noakes, T D; Tucker, R

    2015-01-15

    The purpose of this study was to analyze the cerebral oxygenation response to maximal self-paced and incremental exercise in elite Kenyan runners from the Kalenjin tribe. On two separate occasions, 15 elite Kenyan distance runners completed a 5-km time trial (TT) and a peak treadmill speed test (PTS). Changes in cerebral oxygenation were monitored via near-infrared spectroscopy through concentration changes in oxy- and deoxyhemoglobin (Δ[O2Hb] and Δ[HHb]), tissue oxygenation index (TOI), and total hemoglobin index (nTHI). During the 5-km TT (15.2 ± 0.2 min), cerebral oxygenation increased over the first half (increased Δ[O2Hb] and Δ[HHb]) and, thereafter, Δ[O2Hb] remained constant (effect size, ES = 0.33, small effect), whereas Δ[HHb] increased until the end of the trial (P Kalenjin tribe are able to maintain their cerebral oxygenation within a stable range during a self-paced maximal 5-km time trial, but not during an incremental maximal test. This may contribute to their long-distance running success. PMID:25414248

  14. Cerebral oxygen metabolism in patients with early Parkinson's disease

    DEFF Research Database (Denmark)

    Borghammer, Per; Cumming, Paul; Østergaard, Karen; Gjedde, Albert; Rodell, Anders; Bailey, Christopher; Vafaee, Manoucher S

    AIM: Decreased activity of the mitochondrial electron transport chain (ETC) has been implicated in the pathogenesis of Parkinson's disease (PD). This model would most likely predict a decrease in the rate of cerebral oxygen consumption (CMRO(2)). To test this hypothesis, we compared CMRO(2) and...

  15. A venous outflow method for measurement of rapid changes of the cerebral blood flow and oxygen consumption in the rat.

    Science.gov (United States)

    Nilsson, B; Siesjö, B K

    1983-01-01

    A technique for continuous measurement of cerebral venous outflow in the rat is described. The method involves cannulation of one retroglenoid vein close to its exit from the skull, and diversion of cerebral venous blood through a closed extracorporal circuit with a drop recording device, the blood being returned to the central venous circulation via a catheter in the external jugular vein. Occlusion of the contralateral retroglenoid vein increases measured flow and minimizes extracerebral contamination of the diverted cerebral venous blood. The venous outflow system is not further isolated from cerebral or potential extracerebral collaterals. Thus, the mass of tissue drained cannot be exactly defined anatomically. However, the experiments involving changes of PP, arterial CO2 tension, and induction of epileptic seizure activity, and simultaneous indirect measurements with radioactive tracer technique, indicate that significant extracerebral contamination does not occur and that in short term measurements the venous outflow represents cerebral blood flow (CBF) in a constant mass of (dorsal and central, mainly forebrain) cerebral tissue. Measurement of arterial blood pressure and pressure in the cisterna magna allows calculation of cerebral perfusion pressure (PP). By simultaneous measurement of arterial and cerebral venous oxygen content changes in cerebral oxygen consumption (CMRO2) can be calculated. The method has been applied to document several situations of transient CBF and CMRO2 changes. PMID:6658967

  16. Cerebral oxygenation and metabolism during exercise following three months of endurance training in healthy overweight males

    DEFF Research Database (Denmark)

    Seifert, T; Rasmussen, P; Brassard, P;

    2009-01-01

    Endurance training improves muscular and cardiovascular fitness, but the effect on cerebral oxygenation and metabolism remains unknown. We hypothesized that 3 mo of endurance training would reduce cerebral carbohydrate uptake with maintained cerebral oxygenation during submaximal exercise. Healthy...... overweight males were included in a randomized, controlled study (training: n = 10; control: n = 7). Arterial and internal jugular venous catheterization was used to determine concentration differences for oxygen, glucose, and lactate across the brain and the oxygen-carbohydrate index [molar uptake of oxygen...... training attenuates the cerebral metabolic response to submaximal exercise, as reflected in a lower carbohydrate uptake and maintained cerebral oxygenation....

  17. Ventilation onset prior to umbilical cord clamping (physiological-based cord clamping improves systemic and cerebral oxygenation in preterm lambs.

    Directory of Open Access Journals (Sweden)

    Graeme R Polglase

    Full Text Available As measurement of arterial oxygen saturation (SpO2 is common in the delivery room, target SpO2 ranges allow clinicians to titrate oxygen therapy for preterm infants in order to achieve saturation levels similar to those seen in normal term infants in the first minutes of life. However, the influence of the onset of ventilation and the timing of cord clamping on systemic and cerebral oxygenation is not known.We investigated whether the initiation of ventilation, prior to, or after umbilical cord clamping, altered systemic and cerebral oxygenation in preterm lambs.Systemic and cerebral blood-flows, pressures and peripheral SpO2 and regional cerebral tissue oxygenation (SctO2 were measured continuously in apnoeic preterm lambs (126±1 day gestation. Positive pressure ventilation was initiated either 1 prior to umbilical cord clamping, or 2 after umbilical cord clamping. Lambs were monitored intensively prior to intervention, and for 10 minutes following umbilical cord clamping.Clamping the umbilical cord prior to ventilation resulted in a rapid decrease in SpO2 and SctO2, and an increase in arterial pressure, cerebral blood flow and cerebral oxygen extraction. Ventilation restored oxygenation and haemodynamics by 5-6 minutes. No such disturbances in peripheral or cerebral oxygenation and haemodynamics were observed when ventilation was initiated prior to cord clamping.The establishment of ventilation prior to umbilical cord clamping facilitated a smooth transition to systemic and cerebral oxygenation following birth. SpO2 nomograms may need to be re-evaluated to reflect physiological management of preterm infants in the delivery room.

  18. Noninvasive cerebral blood oxygenation monitoring: clinical test of multiwavelength optoacoustic system

    Science.gov (United States)

    Petrov, Y. Y.; Prough, D. S.; Petrova, I.; Patrikeev, I. A.; Cicenaite, I.; Esenaliev, R. O.

    2007-02-01

    Continuous monitoring of cerebral blood oxygenation is critically important for treatment of patients with life-threatening conditions like severe brain injury or during cardiac surgery. We designed and built a novel multiwavelength optoacoustic system for noninvasive, continuous, and accurate monitoring of cerebral blood oxygenation. We use an Optical Parametric Oscillator as a light source. We successfully tested the system in vitro as well as in vivo in large animals (sheep) through thick tissues overlying blood vessels which drain venous blood out of the brain (e.g., superior sagittal sinus or jugular vein). Here we present the results of clinical tests of the system for continuous noninvasive cerebral blood oxygenation monitoring in the internal jugular vein of healthy volunteers. We applied our custom-built optoacoustic probe (which incorporated a wide-band acoustic transducer and an optical fiber) to the neck area overlying the internal jugular vein. We performed measurements with volunteers at 18 wavelengths in the near-infrared spectral range. Despite a thick layer of overlying connective tissue and low energy used in the experiments, we recorded signals with high signal-to-noise ratios for all volunteers. We found that the temporal (independent of signal amplitude) parameters of recorded profiles for different levels of blood oxygenation correlated well with the spectrum of effective attenuation coefficients of blood.

  19. Influence of cerebrovascular arteriosclerosis on cerebral oxygenation during exercise

    International Nuclear Information System (INIS)

    Although it is assumed that cerebral oxygenation during exercise is influenced by both cardiopulmonary function and cerebrovascular arteriosclerosis, the latter factor has not been fully clarified. In the present study the relationship between the degree of cerebrovascular arteriosclerosis and cerebral oxygenation during exercise was investigated. A total of 109 patients (69 patients with coronary artery disease, 40 patients with hypertensive heart disease) (61.7±9.7 years) performed a symptom-limited exercise test with respiratory gas measurements (CPX). From the respiratory gas analysis, peak O2 uptake (VO2), the slope of the increase in VO2 to the increase in work rate (ΔVO2/ΔWR), and the slope of the increase in ventilation to the increase in CO2 output (VE/VCO2 slope) were calculated. Oxyhemoglobin (O2Hb) at the forehead was monitored using near-infrared spectroscopy. The brain ischemic score was counted based upon fluid-attenuated inversion recovery images of magnetic resonance imaging and expressed from 0 to 4. When compared with patients with a lower ischemic score (2Hb during exercise (-1.08±2.7 vs 0.77±4.1 μmol/L, p=0.011). Of brain ischemic score, left ventricular ejection fraction, peak VO2, ΔVO2/ΔWR, and the VE/VCO2 slope, ΔVO2/ΔWR was found to be the sole independent index determining cerebral O2Hb during exercise. The CPX parameters were also significantly related to the degree of cerebrovascular arteriosclerosis. Although cerebral oxygenation during exercise is mainly related to cardiopulmonary function, the degree of cerebrovascular arteriosclerosis partly influences cerebral oxygenation in patients with risk factors for atherosclerosis. (author)

  20. Oxygen distributions within tissue by phosphorescence quenching

    Science.gov (United States)

    Wilson, David F.; Grosul, Pavel; Rozhkov, Vladimir; Dugan, Benjamin W.; Reitveld, Ivo; Vinogradov, Sergei A.

    2002-06-01

    Oxygen dependent quenching of phosphorescence is a powerful method for measuring oxygen. Phosphors are now available that absorb and emit in the near IR region of the spectrum, are nontoxic, and remain in the blood, allowing rapid measure of oxygen through out selected tissue volumes. In vivo measurements are non-invasive except for the need to inject phosphor into the blood, and phosphorescence lifetimes can be measured without interference by tissue pigments that absorb or fluorescence at the measurement wavelengths. Phosphorescence quenching is uniquely useful for: (1) imaging oxygen in optically clear media or in the surface layer of the tissue, such as in the retina of the eye; (2) determining the distribution of oxygen in media, such as tissue, which have heterogeneous distributions by deconvoluting phosphorescence decay dat. These can be used to calculate the corresponding oxygen histograms. Measurement in 2D grids can b used to construct contour maps of the fraction of the sampled tissue volume with any selected range of oxygen pressures. These maps accurately show the location and size of any regions of hypoxia within the sampled tissue.

  1. Comparative study between the effects of dexmedetomidine and propofol on cerebral oxygenation during sedation at pediatric cardiac catheterization

    Directory of Open Access Journals (Sweden)

    Murat Cetin

    2016-01-01

    Full Text Available Introduction: Nowadays, assessment of brain oxygen saturation, which is simply appliable and noninvasive method, can provide the anesthesia plans to be optimized according to the needs of the brain, which is the main target organ. Brain may be exposed to hypoxia due to supply-demand imbalance of oxygen not only in general anesthesia procedures but also in sedation practices. The aim of the study is to compare the effects of dexmedetomidine and propofol which are widely used agents for pediatric catheterization procedures on brain oxygen saturation using Fore-Sight. Material and Methods: A total of 44 patients undergoing diagnostic cardiac catheterization between 1 and 18 years old were included in the study. All patients, who were randomly divided into two groups, had ASA physical status I-II. In Group Propofol (Group P, n = 22,induction of sedation was made by midazolam (0.5 mg,iv + propofol (1m/kg,iv, and in Group Dexmedetomidine (Group D, n = 22, induction of sedation was made by midazolam (0.5 mg,iv +dexmedetomidine (1mcg/kg, iv. Throughout the sedation, cerebral tissue oxygen saturation (SctO 2 was recorded by Fore-Sight in addition to routine monitoring. Results: There were no statistically significant differences between the groups in terms of demographic data, hemodynamic data and sedation scores. On other hand, statistically significant decreases in cerebral tissue oxygen saturation were detected especially at 5th and 10th minutes, in Group D, while cerebral oxygenation level did not decrease in Group P. Though, statistically significant difference was determined between two groups in terms of cerebral oxygen saturation, the obtained data was not interpreted as cerebral desaturation. Conclusion: As a conclusion, there was a statistically significant but clinically insignificant decrease in cerebral tissue oxygen saturation in dexmedetomidine group compared to propofol group. Although it does not seem to be important in hemodynamic

  2. EFFECTS OF RAPAMYCIN ON CEREBRAL OXYGEN SUPPLY AND CONSUMPTION DURING REPERFUSION AFTER CEREBRAL ISCHEMIA

    Science.gov (United States)

    CHI, O. Z.; BARSOUM, S.; VEGA-COTTO, N. M.; JACINTO, E.; LIU, X.; MELLENDER, S. J.; WEISS, H. R.

    2016-01-01

    Abstract—Activation of the mammalian target of rapamycin (mTOR) leads to cell growth and survival. We tested the hypothesis that inhibition of mTOR would increase infarct size and decrease microregional O2 supply/consumption balance after cerebral ischemia–reperfusion. This was tested in isoflurane-anesthetized rats with middle cerebral artery blockade for 1 h and reperfusion for 2 h with and without rapamycin (20 mg/kg once daily for two days prior to ischemia). Regional cerebral blood flow was determined using a C14-iodoantipyrine autoradiographic technique. Regional small-vessel arterial and venous oxygen saturations were determined microspectrophotometrically. The control ischemic-reperfused cortex had a similar blood flow and O2 consumption to the contralateral cortex. However, microregional O2 supply/consumption balance was significantly reduced in the ischemic-reperfused cortex. Rapamycin significantly increased cerebral O2 consumption and further reduced O2 supply/consumption balance in the reperfused area. This was associated with an increased cortical infarct size (13.5 ± 0.8% control vs. 21.5 ± 0.9% rapamycin). We also found that ischemia–reperfusion increased AKT and S6K1 phosphorylation, while rapamycin decreased this phosphorylation in both the control and ischemic-reperfused cortex. This suggests that mTOR is important for not only cell survival, but also for the control of oxygen balance after cerebral ischemia–reperfusion. PMID:26742793

  3. Extra-cerebral oxygenation influence on near-infrared-spectroscopy-determined frontal lobe oxygenation in healthy volunteers

    DEFF Research Database (Denmark)

    Sørensen, Henrik; Rasmussen, Peter; Siebenmann, Christoph;

    2015-01-01

    INTRODUCTION: Frontal lobe oxygenation (Sc O2 ) is assessed by spatially resolved near-infrared spectroscopy (SR-NIRS) although it seems influenced by extra-cerebral oxygenation. We aimed to quantify the impact of extra-cerebral oxygenation on two SR-NIRS derived Sc O2 . METHODS: Multiple...

  4. Cerebral blood flow and oxygen metabolism in the Rett syndrome

    International Nuclear Information System (INIS)

    Positron emission tomography (PET) was performed on six patients with the Rett syndrome and the results were compared with the concurrent clinical status of the patients. The cerebral metabolic rate of oxygen (CMRO2) was low in five patients, and oxygen extraction fraction (OEF) was low in four patients; both had a tendency to decline with advancing age. Although the cause is unknown, it is suggested that impaired oxidative metabolism exists in the Rett syndrome. An analysis of the distribution among brain regions showed that the ratios of values for the frontal cortex to those for the temporal cortex for both the cerebral blood flow (CBF) and CMRO2 were lower than those for the controls, which may indicate the loss of of hyperfrontality in the Rett syndrome. Distribution of brain metabolism may be immature in the Rett syndrome. (author)

  5. Cerebral blood flow and oxygen metabolism in the Rett syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Yoshikawa, Hideto; Fueki, Noboru; Suzuki, Hisaharu; Sakuragawa, Norio; Iio, Masaaki (National Central Hospital for Mental, Nervous and Muscular Disorders, Tokyo (Japan))

    1992-05-01

    Positron emission tomography (PET) was performed on six patients with the Rett syndrome and the results were compared with the concurrent clinical status of the patients. The cerebral metabolic rate of oxygen (CMRO{sub 2}) was low in five patients, and oxygen extraction fraction (OEF) was low in four patients; both had a tendency to decline with advancing age. Although the cause is unknown, it is suggested that impaired oxidative metabolism exists in the Rett syndrome. An analysis of the distribution among brain regions showed that the ratios of values for the frontal cortex to those for the temporal cortex for both the cerebral blood flow (CBF) and CMRO{sub 2} were lower than those for the controls, which may indicate the loss of of hyperfrontality in the Rett syndrome. Distribution of brain metabolism may be immature in the Rett syndrome. (author).

  6. Cerebral blood flow and oxygen metabolism in ischemic cerebrovascular disease

    International Nuclear Information System (INIS)

    Using positron emission tomography and 15O-steady state method, cerebral blood flow (CBF), oxygen consumption and oxygen extraction fraction were measured in patients with embolic occlusion and in those with thrombotic occlusion in the carotid system. By the study of patients with embolic occlusion, we evaluated ischemic threshold of CBF for infarction to be 16 ml/100 ml/min. The area of 'penumbra' could be estimated in regions with CBF value just above this threshold. In the patients with thrombotic occlusive lesion, we clarified that the efficiency of the collateral circulation was mainly related to the grade of peripheral atherosclerosis. These findings must be helpful to develop better strategy for treatment of cerebral ischemic disease. (author)

  7. Close temporal coupling of neuronal activity and tissue oxygen responses in rodent whisker barrel cortex

    OpenAIRE

    Li, Jennifer; Bravo, Diego S.; Upton, A. Louise; Gilmour, Gary; Tricklebank, Mark; Fillenz, Marianne; Martin, Chris; Lowry, John P.; Bannerman, David M.; McHugh, Stephen B.

    2011-01-01

    Neuronal activity elicits metabolic and vascular responses, during which oxygen is first consumed and then supplied to the tissue via an increase in cerebral blood flow. Understanding the spatial and temporal dynamics of blood and tissue oxygen (To2 ) responses following neuronal activity is crucial for understanding the physiological basis of functional neuroimaging signals. However, our knowledge is limited because previous To2 measurements have been made at low temporal resolution...

  8. Local cerebral blood flow and local oxygen consumption in prolonged hemiplegic migraine

    International Nuclear Information System (INIS)

    This work gives the results of a study by positron emission tomography of the cerebral blood flow (CBF), oxygen-extraction rate (O2E) and oxygen consumption (CMRO2) during severe and prolonged attack of hemiplegic migraine. The salient facts observed are a high (CBF) in the brain hemisphere affected (ruling out the hypothesis of a persistent cerebral ischemia), together with a collapsed O2E (''luxury perfusion'') and especially preservation of the CMRO2 suggesting a decoupling not only between CBF and CMRO2 but also between CMRO2 and functional state of the tissue. Some time after the attack a new study showed the recoupling between CBF and CMRO2, but with the latter reduced in the affected hemisphere although the clinical and tomodensitometric state had returned to normal. These new observations should not however be improperly generalised to all migraines, given the unusual characteristics of the disorder in our patient

  9. Effect of interscalene anaesthesia on cerebral oxygen saturation.

    Science.gov (United States)

    Soeding, P F; Currigan, D A; Mamo, Y; Hoy, G

    2016-05-01

    Interscalene blockade (ISB) is commonly associated with Horner's syndrome, indicating spread of injectate to the cervical sympathetic chain. Cervical sympathetic nerve activity (SNA) is believed to influence cerebral autoregulation, and a decrease in sympathetic tone may alter cerebral blood flow (CBF). This study investigated whether ISB influenced CBF in patients undergoing shoulder surgery. Patients (n=30) scheduled for elective shoulder arthroscopy were recruited. Cerebral oxygen saturation (ScO2) of the left and right frontal cortices was continuously measured during ISB administration, sedation and anaesthetic induction. Baseline ScO2 was similar in blocked and unblocked sides (74 ± 5% and 73 ± 5% respectively, P=0.70). ScO2 decreased with sedation (-3 ± 3% and -4 ± 3%, P=0.93), and increased with pre-oxygenation and general anaesthesia (P blocked and unblocked sides (P=0.18), or any difference between right- or left-sided ISB. ISB is not associated with an increase in CBF as indicated by ScO2, despite the presence of Horner's syndrome. PMID:27246935

  10. Oxygen diffusion and oxygen effect in tumor tissue

    International Nuclear Information System (INIS)

    The diffusion of oxygen in tumor cords of bronchus carcinoma of the lung have been studied with refined computer methods for solving the diffusion equation in axis symmetric tumor structures. In this tumor configuration we may find three different regions consisting of euoxic cells, hypoxic tumor cells and necrotic parts. In the case of oxygen supply from a capillary inside a cylinder of tumor tissue with radius 200 μm or in a tumor cord of radius 300 μm with oxygen supply by capillaries outside, we get a relation of well oxygenated cells to hypoxic cells approximately as 1:8 or as 1:1.1 respectively. Of course most of the tumor cords observed in histological slices have smaller diameters, so that an average of approximately 20% hypoxic cells can be assumed. Based on the work of Ardenne, the diffusion of oxygen and glucose in a tumor of type DS-carcinosarcom has been investigated in both intact tumor and tumor treated with ionizing radiation. We can show that a strong reoxygenation effect takes place in that the well supplied regions may increase in some tumor configurations up to a factor of four by volume. The biological consequences of the oxygen pressure determined in tumor cells are discussed in detail. The investigation of oxygen diffusion in the intercapillary tumor region should give a quantitative physical basis for considering the oxygen effect with the aim to explain the advantages of neutron therapy against conventional radiotherapy. (orig./MG)

  11. Monitoring cerebral oxygen saturation during cardiopulmonary bypass using near-infrared spectroscopy: the relationships with body temperature and perfusion rate

    Science.gov (United States)

    Teng, Yichao; Ding, HaiShu; Gong, Qingcheng; Jia, Zaishen; Huang, Lan

    2006-03-01

    During cardiopulmonary bypass (CPB) because of weak arterial pulsation, near-IR spectroscopy (NIRS) is almost the only available method to monitor cerebral oxygenation noninvasively. Our group develops a NIRS oximeter to monitor regional cerebral oxygenation especially its oxygen saturation (rScO2). To achieve optimal coupling between the sensor and human brain, the distances between the light source and the detectors on it are properly chosen. The oximeter is calibrated by blood gas analysis, and the results indicate that its algorithm is little influenced by either background absorption or overlying tissue. We used it to measure the rScO2 of 15 patients during CPB. It is shown that rScO2 is negatively correlated with body temperature and positively with perfusion rate. There are two critical stages during CPB when rScO2 might be relatively low: one is the low-perfusion-rate stage, the other is the early rewarming stage. During cooling, the changes of total hemoglobin concentration (CtHb) compared with its original value is also monitored. It is shown that CtHb decreases to a small extent, which may mainly reflect cerebral vasoconstriction induced by cooling. All these results indicate that NIRS can be used to monitor cerebral oxygenation to protect cerebral tissue during CPB.

  12. Simple exercises that significantly increase cerebral blood flow and cerebral oxygenation

    CERN Document Server

    Gersten, Alexander; Raz, Amir; Fried, Robert

    2011-01-01

    We tested the hypothesis that simple exercises may significantly increase cerebral blood flow (CBF) and/or cerebral oxygenation. Eighteen subjects ranging in age from nineteen to thirty nine participated in a four-stage study during which measurements of end tidal CO_2 (EtCO2 - by capnometer) and local brain oxygenation (by near-infrared spectroscopy (NIRS) sensor) were taken. The four stages were 1) baseline, 2) breathing exercises, 3) solving an arithmetic problem, and 4) biofeedback. During the breathing exercises there was a significant increase in EtCO2 indicating a significant increase in global CBF. The increase in global CBF was estimated on the basis of a theoretical model. During the arithmetic and biofeedback tasks there was a significant increase in the local (Fp1) oxygenation, but it varied between the different participants. The results may lead to new clinical applications of CBF and brain oxygenation monitoring and behavioral control. We foresee future more detailed investigations in the contr...

  13. Activation-induced resetting of cerebral oxygen and glucose uptake in the rat

    DEFF Research Database (Denmark)

    Madsen, P L; Linde, R; Hasselbalch, S G;

    1998-01-01

    In the clinical setting it has been shown that activation will increase cerebral glucose uptake in excess of cerebral oxygen uptake. To study this phenomenon further, this study presents an experimental setup that enables precise determination of the ratio between cerebral uptake of glucose and...... oxygen in the awake rat. Global CBF was measured by the Kety-Schmidt technique, and the ratio between cerebral uptake rates for oxygen, glucose, and lactate was calculated from cerebral arterial-venous differences. During baseline conditions, rats were kept in a closed box designed to minimize...... interference. During baseline conditions CBF was 1.08 +/- 0.25 mL x g(-1) x minute(-1), and the cerebral oxygen to glucose uptake ratio was 5.5. Activation was induced by opening the sheltering box for 6 minutes. Activation increased CBF to 1.81 mL x g(-1) x minute(-1). During activation cerebral glucose...

  14. Influence of moderate hypothermia on cerebral oxygenation in pigs with intracranial hypertension

    Institute of Scientific and Technical Information of China (English)

    Yinghui Bao; Yumin Liang; Jiyao Jiang; Qizhong Luo; Yicheng Lu

    2007-01-01

    BACKGROUND: Moderate hypothermia is one of the effective therapeutic methods for head injury in recent years, there are many mechanisms of moderate hypothermia for brain protection, and its influence on cerebral oxygenation is also one of them.OBJECTIVE: To observe the influence of moderate hypothermia on cerebral oxygenation of animals with acute intracranial hypertension, and further investigate the protective mechanism of moderate hypothermia. DESIGN: A randomized controlled trial.SETTING: Department of Neurosurgery, Renji Hospital affiliated to the Medical College of Shanghai Jiao Tong University.MATERIALS: Twenty healthy little pigs, either male or female, weighing 4.5 - 5.5 kg, were used. Neurotrend-typed multiparameter monitoring system (Diametrics Company, British); CMA/100micro-injection pump (Carnegie Company, Sweden).METHODS: The experiment was conducted in the Changzheng Hospital affiliated to the Second Military Medical University of Chinese PLA in November, 2001. The pigs were randomized into two groups: the normothermia group (control group, n =10) and moderate hypothermia group (n =10). ①Bilateral femoral arteries were separated, one was connected to pressometer for monitoring mean arterial pressure (MEP), and the other for analysis of blood gases [including peripheral blood Ph value, arterial partial pressure of carbon dioxide (PaCCh), arterial partial pressure of carbon dioxide (PaCO2), HCO3-].②Rectal temperature was monitored with mercurial thermometer.③Intracranial pressure was monitored using Camino optic ICP probe placed in the subdural space. ④Neurotrend multiparameter monitoring sensor was inserted into the white matter for about 4 cm to determine cerebral perfusion pressure (CPP, CPP=MAP(ICP), brain tissue partial oxygen pressure (PO2), partial pressure of carbon dioxide (PCCh), HCO3- and brain temperature. The rectal temperature of animals in the moderate hypothermia group was lowered to 34℃ using ice bags, and the body

  15. Cutaneous vasoconstriction affects near-infrared spectroscopy determined cerebral oxygen saturation during administration of norepinephrine

    DEFF Research Database (Denmark)

    Sørensen, Niels Henrik Breiner; Secher, Niels H; Siebenmann, Christoph;

    2012-01-01

    Perioperative optimization of spatially resolved near-infrared spectroscopy determined cerebral frontal lobe oxygenation (scO2) may reduce postoperative morbidity. Norepinephrine is routinely administered to maintain cerebral perfusion pressure and, thereby, cerebral blood flow, but norepinephrine...... reduces the scO2. We hypothesized that norepinephrine-induced reduction in scO2 is influenced by cutaneous vasoconstriction....

  16. Optical characterization of two-layered turbid media for non-invasive, absolute oximetry in cerebral and extracerebral tissue.

    Directory of Open Access Journals (Sweden)

    Bertan Hallacoglu

    Full Text Available We introduce a multi-distance, frequency-domain, near-infrared spectroscopy (NIRS method to measure the optical coefficients of two-layered media and the thickness of the top layer from diffuse reflectance measurements. This method features a direct solution based on diffusion theory and an inversion procedure based on the Levenberg-Marquardt algorithm. We have validated our method through Monte Carlo simulations, experiments on tissue-like phantoms, and measurements on the forehead of three human subjects. The Monte Carlo simulations and phantom measurements have shown that, in ideal two-layered samples, our method accurately recovers the top layer thickness (L, the absorption coefficient (µ a and the reduced scattering coefficient (µ' s of both layers with deviations that are typically less than 10% for all parameters. Our method is aimed at absolute measurements of hemoglobin concentration and saturation in cerebral and extracerebral tissue of adult human subjects, where the top layer (layer 1 represents extracerebral tissue (scalp, skull, dura mater, subarachnoid space, etc. and the bottom layer (layer 2 represents cerebral tissue. Human subject measurements have shown a significantly greater total hemoglobin concentration in cerebral tissue (82±14 µM with respect to extracerebral tissue (30±7 µM. By contrast, there was no significant difference between the hemoglobin saturation measured in cerebral tissue (56%±10% and extracerebral tissue (62%±6%. To our knowledge, this is the first time that an inversion procedure in the frequency domain with six unknown parameters with no other prior knowledge is used for the retrieval of the optical coefficients and top layer thickness with high accuracy on two-layered media. Our absolute measurements of cerebral hemoglobin concentration and saturation are based on the discrimination of extracerebral and cerebral tissue layers, and they can enhance the impact of NIRS for cerebral hemodynamics and

  17. Cerebral oxygenation decreases during exercise in humans with beta-adrenergic blockade

    DEFF Research Database (Denmark)

    Seifert, T.; Rasmussen, P.; Secher, Niels H.;

    2009-01-01

    AIM: Beta-blockers reduce exercise capacity by attenuated increase in cardiac output, but it remains unknown whether performance also relates to attenuated cerebral oxygenation. METHODS: Acting as their own controls, eight healthy subjects performed a continuous incremental cycle test to exhaustion...... with or without administration of the non-selective beta-blocker propranolol. Changes in cerebral blood flow velocity were measured with transcranial Doppler ultrasound and those in cerebral oxygenation were evaluated using near-infrared spectroscopy and the calculated cerebral mitochondrial oxygen...

  18. Monitoring cerebral oxygenation in a pediatric patient undergoing surgery for vascular ring.

    Science.gov (United States)

    Joshi, Reena K; Motta, Pablo; Horibe, Mayumi; Mossad, Emad

    2006-02-01

    Regional cerebral oxygenation can be monitored using near-infrared spectroscopy (NIRS). Inadequacy of collateral cerebral circulation and regional cerebral ischemia during cardiac and vascular surgery may be detected by the use of NIRS monitoring. We report a 2-year-old child who underwent surgical repair of vascular ring and subclavian reimplantation, where use of NIRS helped in early detection and timely intervention to prevent prolonged cerebral ischemia. PMID:16430416

  19. Metabolic Prosthesis for Oxygenation of Ischemic Tissue

    Energy Technology Data Exchange (ETDEWEB)

    Greenbaum, Elias [ORNL

    2009-01-01

    This communication discloses new ideas and preliminary results on the development of a "metabolic prosthesis" for local oxygenation of ischemic tissue under physiological neutral conditions. We report for the first time the selective electrolysis of physiological saline by repetitively pulsed charge-limited electrolysis for the production of oxygen and suppression of free chlorine. For example, using 800 A amplitude current pulses and <200 sec pulse durations, we demonstrated prompt oxygen production and delayed chlorine production at the surface of a shiny 0.85 mm diameter spherical platinum electrode. The data, interpreted in terms of the ionic structure of the electric double layer, suggest a strategy for in situ production of metabolic oxygen via a new class of "smart" prosthetic implants for dealing with ischemic disease such as diabetic retinopathy. We also present data indicating that drift of the local pH of the oxygenated environment can be held constant using a feedback-controlled three electrode electrolysis system that chooses anode and cathode pair based on pH data provided by local microsensors. The work is discussed in the context of diabetic retinopathy since surgical techniques for multielectrode prosthetic implants aimed at retinal degenerative diseases have been developed.

  20. Effects of transection of cervical sympathetic trunk on cerebral infarct volume and oxygen free radical levels in rats with focal cerebral ischemia/reperfusion injury

    Institute of Scientific and Technical Information of China (English)

    Liangzhi Xiong; Yongxia Shi; Feng Xiao; Qingxiu Wang

    2008-01-01

    BACKGROUND: Stellate ganglion block (SGB) plays a protective role on the brain, but the precise mechanism of action is not clear.OBJECTIVE: To simulate SGB by transection of the cervical sympathetic trunk (TCST) and to investigate the TCST effects on changes in cerebral infarct volume and oxygen free radical levels in rats with focal cerebral ischemia/reperfusion injury.DESIGN, TIME AND SETTING: A complete randomized control animal experiment was performed at the Institute of Neurological Diseases of Taihe Hospital, Yunyang Medical College from February to December 2005.MATERIALS: A total of 101 healthy Wistar rats, weighing 280-320g, of both genders, aged 17-18 weeks, were used in this study. 2,3,5-triphenyltetrazolium chloride (TTC) was purchased from Changsha Hongyuan Biological Company. Superoxide dismutase (SOD), malondialdehyde (MDA) and nitric oxide (NO) assay kits were provided by Nanjing Jiancheng Bioengineering Institute.METHODS: Rats were randomly divided into a TCST group, a model group and a sham operation group. Successful models were included in the final analysis, with at least 20 rats in each group. After TCST, rat models of focal cerebral ischemia/reperfusion injury were established in the TCST group by receiving middle cerebral artery occlusion (MCAO) by the intraluminal suture method for 2 hours, followed by 24 hours of reperfusion. Rat models of focal cerebral ischemia/reperfusion injury were made in the model group. Rats in the sham operation group underwent experimental procedures as for the model group, threading depth of 10mm, and middle cerebral artery was not ligated.MAIN OUTCOME MEASURES: Brain tissue sections of ten rats from each group were used to measure cerebral infarct volume by TTC staining. Brain tissue homogenate of another ten rats from each group was used to detect SOD activities, MDA contents and NO levels. Rat neurological function was assessed by neurobehavioral measures.RESULTS: Cerebral infarct volume was bigger in the

  1. Mechanical indentation improves cerebral blood oxygenation signal quality of functional near-infrared spectroscopy (fNIRS) during breath holding

    Science.gov (United States)

    Vogt, William C.; Romero, Edwin; LaConte, Stephen M.; Rylander, Christopher G.

    2013-03-01

    Functional near-infrared spectroscopy (fNIRS) is a well-known technique for non-invasively measuring cerebral blood oxygenation, and many studies have demonstrated that fNIRS signals can be related to cognitive function. However, the fNIRS signal is attenuated by the skin, while scalp blood content has been reported to influence cerebral oxygenation measurements. Mechanical indentation has been shown to increase light transmission through soft tissues by causing interstitial water and blood flow away from the compressed region. To study the effects of indentation on fNIRS, a commercial fNIRS system with 16 emitter/detector pairs was used to measure cerebral blood oxygenation at 2 Hz. This device used diffuse reflectance at 730 nm and 850 nm to calculate deoxy- and oxy-hemoglobin concentrations. A borosilicate glass hemisphere was epoxied over each sensor to function as both an indenter and a lens. After placing the indenter/sensor assembly on the forehead, a pair of plastic bands was placed on top of the fNIRS headband and strapped to the head to provide uniform pressure and tightened to approx. 15 N per strap. Cerebral blood oxygenation was recorded during a breath holding regime (15 second hold, 15 second rest, 6 cycles) in 4 human subjects both with and without the indenter array. Results showed that indentation increased raw signal intensity by 85 +/- 35%, and that indentation increased amplitude of hemoglobin changes during breath cycles by 313% +/- 105%. These results suggest that indentation improves sensing of cerebral blood oxygenation, and may potentially enable sensing of deeper brain tissues.

  2. Cerebral oxygen and glucose metabolism and blood flow in mitochondrial encephalomyopathy: a PET study

    International Nuclear Information System (INIS)

    Cerebral blood flow (CBF), oxygen metabolism (CMRO2), and glucose metabolism (CMRGlc) were measured using positron emission tomography in five patients diagnosed as having mitochondrial encephalomyopathy. The molar ratio between the oxygen and glucose consumptions was reduced diffusely, as CMRO2 was markedly decreased and CMRGlc was slightly reduced. The CBF showed less changes. The CBF increase on hypercapnia was smaller than normal, though this was not significant. CBF with hypocapnia demonstrated a significant reduction compared with the normal. These results suggest that oxidative metabolism is impaired and anaerobic glycolysis relatively stimulated, due to a primary defect of mitochondrial function, and that mild lactic acidosis occurs in brain tissue because of impaired utilisation of pyruvate in the TCA cycle. As these findings appear to indicate directly a characteristic of this disease, such measurements may be a useful tool for assessment of the pathophysiology and for diagnosis of mitochondrial encephalomyopathy. (orig.). With 1 fig., 4 tabs

  3. Cerebral oxygen saturation monitoring during hypotensive anesthesia in shoulder arthroscopy: A comparative study between dexmedetomidine and esmolol

    OpenAIRE

    Khaled Mohammed Maghawry; Ashraf El Sayed El-Agamy; Wael Ibrahim Tahir; Ayman F. Zein

    2015-01-01

    Background: Beach chair position (BCP) is used in arthroscopic shoulder operations for its advantages. The BCP together with deliberate hypotension used to decrease intraoperative blood loss during arthroscopic shoulder procedures, this may have risk to cause postoperative neurological insults. Dexmedetomidine and esmolol are used to induce deliberate hypotension. Near-infrared spectroscopy (NIRS) provides a non-invasive technique of continuous monitoring of regional cerebral tissue oxygen sa...

  4. Higher cerebral oxygen saturation may provide higher urinary output during continuous regional cerebral perfusion

    Directory of Open Access Journals (Sweden)

    Tomoyasu Takahiro

    2008-10-01

    Full Text Available Abstract Objective We examined the hypothesis that higher cerebral oxygen saturation (rSO2 during RCP is correlated with urinary output. Methods Between December 2002 and August 2006, 12 patients aged 3 to 61 days and weighing 2.6 to 3.4 kg underwent aortic arch repair with RCP. Urinary output and rSO2 were analyzed retrospectively. Data were assigned to either of 2 groups according to their corresponding rSO2: Group A (rSO2 ≦ 75% and Group B (rSO2 Results Seven and 5 patients were assigned to Group A and Group B, respectively. Group A was characterized by mean radial arterial pressure (37.9 ± 9.6 vs 45.8 ± 7.8 mmHg; P = 0.14 and femoral arterial pressure (6.7 ± 6.1 vs 20.8 ± 14.6 mmHg; P = 0.09 compared to Group B. However, higher urinary output during CPB (1.03 ± 1.18 vs 0.10 ± 0.15 ml·kg-1·h-1; P = 0.03. Furthermore our results indicate that a higher dose of Chlorpromazine was used in Group A (2.9 ± 1.4 vs 1.7 ± 1.0 mg/kg; P = 0.03. Conclusion Higher cerebral oxygenation may provide higher urinary output due to higher renal blood flow through collateral circulation.

  5. Cerebral oxygen saturation: graded response to carbon dioxide with isoxia and graded response to oxygen with isocapnia.

    Directory of Open Access Journals (Sweden)

    W Alan C Mutch

    Full Text Available BACKGROUND: Monitoring cerebral saturation is increasingly seen as an aid to management of patients in the operating room and in neurocritical care. How best to manipulate cerebral saturation is not fully known. We examined cerebral saturation with graded changes in carbon dioxide tension while isoxic and with graded changes in oxygen tension while isocapnic. METHODOLOGY/PRINCIPAL FINDINGS: The study was approved by the Research Ethics Board of the University Health Network at the University of Toronto. Thirteen studies were undertaken in healthy adults with cerebral oximetry by near infrared spectroscopy. End-tidal gas concentrations were manipulated using a model-based prospective end-tidal targeting device. End-tidal carbon dioxide was altered ±15 mmHg from baseline in 5 mmHg increments with isoxia (clamped at 110±4 mmHg. End-tidal oxygen was changed to 300, 400, 500, 80, 60 and 50 mmHg under isocapnia (37±2 mmHg. Twelve studies were completed. The end-tidal carbon dioxide versus cerebral saturation fit a linear relationship (R(2 = 0.92±0.06. The end-tidal oxygen versus cerebral saturation followed log-linear behaviour and best fit a hyperbolic relationship (R(2 = 0.85±0.10. Cerebral saturation was maximized in isoxia at end-tidal carbon dioxide of baseline +15 mmHg (77±3 percent. Cerebral saturation was minimal in isocapnia at an end-tidal oxygen tension of 50 mmHg (61±3 percent. The cerebral saturation during normoxic hypocapnia was equivalent to normocapnic hypoxia of 60 mmHg. CONCLUSIONS/SIGNIFICANCE: Hypocapnia reduces cerebral saturation to an extent equivalent to moderate hypoxia.

  6. Cerebral venous blood oxygenation monitoring during hyperventilation in healthy volunteers with a novel optoacoustic system

    Science.gov (United States)

    Petrov, Andrey; Prough, Donald S.; Petrov, Irene Y.; Petrov, Yuriy; Deyo, Donald J.; Henkel, Sheryl N.; Seeton, Roger; Esenaliev, Rinat O.

    2013-03-01

    Monitoring of cerebral venous oxygenation is useful to facilitate management of patients with severe or moderate traumatic brain injury (TBI). Prompt recognition of low cerebral venous oxygenation is a key to avoiding secondary brain injury associated with brain hypoxia. In specialized clinical research centers, jugular venous bulb catheters have been used for cerebral venous oxygenation monitoring and have demonstrated that oxygen saturation capnography. Good temporal correlation between decreases in optoacoustically measured SSS oxygenation and decreases in EtCO2 was obtained. Decreases in EtCO2 from normal values (35-45 mmHg) to 20-25 mmHg resulted in SSS oxygenation decreases by 3-10%. Intersubject variability of the responses may relate to nonspecific brain activation associated with voluntary hyperventilation. The obtained data demonstrate the capability of the optoacoustic system to detect in real time minor changes in the SSS blood oxygenation.

  7. Ductus arteriosus with left-to-right shunt during venoarterial extracorporeal membrane oxygenation: effects on cerebral oxygenation and hemodynamics.

    NARCIS (Netherlands)

    Heyst, A.F.J. van; Staak, F.H.J.M. van der; Hopman, J.C.W.; Tanke, R.B.; Sengers, R.C.A.; Liem, K.D.

    2003-01-01

    OBJECTIVE: To investigate the effect on cerebral oxygenation and hemodynamics of a patent ductus arteriosus with left-to-right shunt during venoarterial extracorporeal membrane oxygenation in a lamb model. DESIGN: Prospective intervention study in animals. SETTING: Animal research laboratory of a un

  8. Acetylbritannilactone Modulates MicroRNA-155-Mediated Inflammatory Response in Ischemic Cerebral Tissues.

    Science.gov (United States)

    Wen, Ya; Zhang, Xiangjian; Dong, Lipeng; Zhao, Jingru; Zhang, Cong; Zhu, Chunhua

    2015-01-01

    Inflammatory responses play a critical role in ischemic brain injury. MicroRNA-155 (miR-155) induces the expression of inflammatory cytokines, and acetylbritannilactone (ABL) exerts potent antiinflammatory actions by inhibiting expression of inflammation-related genes. However, the functions of miR-155 and the actual relationship between ABL and miR-155 in ischemia-induced cerebral inflammation remain unclear. In this study, cerebral ischemia of wild-type (WT) and miR-155(-/-) mice was induced by permanent middle cerebral artery occlusion (MCAO). pAd-miR-155 was injected into the lateral cerebral ventricle 24 h before MCAO to induce miR-155 overexpression. MCAO mice and oxygen-glucose deprivation (OGD)-treated BV2 cells were used to examine the effects of ABL and miR-155 overexpression or deletion on the expression of proinflammatory cytokines. We demonstrated that ABL treatment significantly reduced neurological deficits and cerebral infarct volume by inhibiting tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) expression in ischemic cerebral tissue and OGD-treated BV2 cells. Mechanistic studies suggested that the observed decrease in TNF-α and IL-1β expression was attributable to the ABL-induced suppression of the expression of nuclear factor-kappa B (NF-κB) and Toll-like receptor 4 (TLR4). We further found that miR-155 promoted TNF-α and IL-1β expression by upregulating TLR4 and downregulating the expression of suppressor of cytokine signaling 1 (SOCS1) and myeloid differentiation primary response gene 88 (MyD88), while ABL exerted an inhibitory effect on miR-155-mediated gene expression. In conclusion, miR-155 mediates inflammatory responses in ischemic cerebral tissue by modulating TLR4/MyD88 and SOCS1 expression, and ABL exerts its antiinflammatory action by suppressing miR-155 expression, suggesting a novel miR-155-based therapy for ischemic stroke. PMID:25811992

  9. Acetazolamide during acute hypoxia improves tissue oxygenation in the human brain.

    Science.gov (United States)

    Wang, Kang; Smith, Zachary M; Buxton, Richard B; Swenson, Erik R; Dubowitz, David J

    2015-12-15

    Low doses of the carbonic anhydrase inhibitor acetazolamide provides accelerated acclimatization to high-altitude hypoxia and prevention of cerebral and other symptoms of acute mountain sickness. We previously observed increases in cerebral O2 metabolism (CMRO2 ) during hypoxia. In this study, we investigate whether low-dose oral acetazolamide (250 mg) reduces this elevated CMRO2 and in turn might improve cerebral tissue oxygenation (PtiO2 ) during acute hypoxia. Six normal human subjects were exposed to 6 h of normobaric hypoxia with and without acetazolamide prophylaxis. We determined CMRO2 and cerebral PtiO2 from MRI measurements of cerebral blood flow (CBF) and cerebral venous O2 saturation. During normoxia, low-dose acetazolamide resulted in no significant change in CBF, CMRO2 , or PtiO2 . During hypoxia, we observed increases in CBF [48.5 (SD 12.4) (normoxia) to 65.5 (20.4) ml·100 ml(-1)·min(-1) (hypoxia), P < 0.05] and CMRO2 [1.54 (0.19) to 1.79 (0.25) μmol·ml(-1)·min(-1), P < 0.05] and a dramatic decline in PtiO2 [25.0 to 11.4 (2.7) mmHg, P < 0.05]. Acetazolamide prophylaxis mitigated these rises in CBF [53.7 (20.7) ml·100 ml(-1)·min(-1) (hypoxia + acetazolamide)] and CMRO2 [1.41 (0.09) μmol·ml(-1)·min(-1) (hypoxia + acetazolamide)] associated with acute hypoxia but also reduced O2 delivery [6.92 (1.45) (hypoxia) to 5.60 (1.14) mmol/min (hypoxia + acetazolamide), P < 0.05]. The net effect was improved cerebral tissue PtiO2 during acute hypoxia [11.4 (2.7) (hypoxia) to 16.5 (3.0) mmHg (hypoxia + acetazolamide), P < 0.05]. In addition to its renal effect, low-dose acetazolamide is effective at the capillary endothelium, and we hypothesize that local interruption in cerebral CO2 excretion accounts for the improvements in CMRO2 and ultimately in cerebral tissue oxygenation during hypoxia. This study suggests a potentially pivotal role of cerebral CO2 and pH in modulating CMRO2 and PtiO2 during acute hypoxia. PMID:26472861

  10. Multichannel optical brain imaging to separate cerebral vascular, tissue metabolic, and neuronal effects of cocaine

    Science.gov (United States)

    Ren, Hugang; Luo, Zhongchi; Yuan, Zhijia; Pan, Yingtian; Du, Congwu

    2012-02-01

    Characterization of cerebral hemodynamic and oxygenation metabolic changes, as well neuronal function is of great importance to study of brain functions and the relevant brain disorders such as drug addiction. Compared with other neuroimaging modalities, optical imaging techniques have the potential for high spatiotemporal resolution and dissection of the changes in cerebral blood flow (CBF), blood volume (CBV), and hemoglobing oxygenation and intracellular Ca ([Ca2+]i), which serves as markers of vascular function, tissue metabolism and neuronal activity, respectively. Recently, we developed a multiwavelength imaging system and integrated it into a surgical microscope. Three LEDs of λ1=530nm, λ2=570nm and λ3=630nm were used for exciting [Ca2+]i fluorescence labeled by Rhod2 (AM) and sensitizing total hemoglobin (i.e., CBV), and deoxygenated-hemoglobin, whereas one LD of λ1=830nm was used for laser speckle imaging to form a CBF mapping of the brain. These light sources were time-sharing for illumination on the brain and synchronized with the exposure of CCD camera for multichannel images of the brain. Our animal studies indicated that this optical approach enabled simultaneous mapping of cocaine-induced changes in CBF, CBV and oxygenated- and deoxygenated hemoglobin as well as [Ca2+]i in the cortical brain. Its high spatiotemporal resolution (30μm, 10Hz) and large field of view (4x5 mm2) are advanced as a neuroimaging tool for brain functional study.

  11. Cerebral blood flow and oxygen metabolism in patients with Parkinson's disease

    International Nuclear Information System (INIS)

    The purpose of this study was to determine functional changes in the cerebral cortex and basal ganglia in Parkinson's disease (PD). Cerebral blood flow (CBF), oxygen extraction fraction (OEF), and cerebral metabolic rate of oxygen (CMRO2) were determined using 0-15 positron emission tomography in 10 PD patients and five age-matched healthy volunteers. There was a tendency among PD patients towards a decreased CBF and CMRO2 in the cerebral cortex and basal ganglia. These values were significantly lower in the frontal cortex in the PD group than the control group. There was no difference in OEF between the groups. A more decreased cerebral oxygen metabolism was observed in patients staged as severer on the scale of Hoehn and Yahr. There was no correlation between cerebral oxygen metabolism and tremor, rigidity, or bradykinesis. A decreased cerebral oxygen metabolism was associated with mental disorders, such as depression, hallucination, and dementia. These results may provide an important clue for the understanding of mesocortical dopaminergic pathway and the relationship between PD and dementia. (N.K.)

  12. Effects of Cortical Spreading Depression on Synaptic Activity, Blood Flow and Oxygen Consumption in Rat Cerebral Cortex

    DEFF Research Database (Denmark)

    Hansen, Henning Piilgaard

    2010-01-01

    As the title of this thesis indicates I have during my PhD studied the effects of cortical spreading depression (CSD) on synaptic activity, blood flow and oxygen consumption in rat cerebral cortex. This was performed in vivo using an open cranial window approach in anesthetized rats. I applied...... two different sets of interneurons. Our data imply that for a given cortical area the amplitude of vascular signals will depend critically on the type of input and hence on the type of neurons activated. In the second study I investigated the effect of cortical spreading depression (CSD) on the evoked...... Laser-Doppler Flowmetry for measurements of cerebral blood flow, glass microelectrodes for recording of synaptic activity – local field potentials – and ongoing cortical electrical activity and a Clark type electrode for measurements of tissue partial pressure of oxygen (tpO2). Offline calculations of...

  13. Novel optoacoustic system for noninvasive continuous monitoring of cerebral venous blood oxygenation

    Science.gov (United States)

    Petrov, Yuriy; Petrov, Irene Y.; Prough, Donald S.; Esenaliev, Rinat O.

    2012-02-01

    Traumatic brain injury (TBI) and spinal cord injury are a major cause of death for individuals under 50 years of age. In the USA alone, 150,000 patients per year suffer moderate or severe TBI. Moreover, TBI is a major cause of combatrelated death. Monitoring of cerebral venous blood oxygenation is critically important for management of TBI patients because cerebral venous blood oxygenation below 50% results in death or severe neurologic complications. At present, there is no technique for noninvasive, accurate monitoring of this clinically important variable. We proposed to use optoacoustic technique for noninvasive monitoring of cerebral venous blood oxygenation by probing cerebral veins such as the superior sagittal sinus (SSS) and validated it in animal studies. In this work, we developed a novel, medical grade optoacoustic system for continuous, real-time cerebral venous blood oxygenation monitoring and tested it in human subjects at normal conditions and during hyperventilation to simulate changes that may occur in patients with TBI. We designed and built a highly-sensitive optoacoustic probe for SSS signal detection. Continuous measurements were performed in the near infrared spectral range and the SSS oxygenation absolute values were automatically calculated in real time using a special algorithm developed by our group. Continuous measurements performed at normal conditions and during hyperventilation demonstrated that hyperventilation resulted in approximately 12% decrease of cerebral venous blood oxygenation.

  14. Nonlinear Model for Capillary-Tissue Oxygen Transport and Metabolism

    OpenAIRE

    Li, Zheng; Yipintsoi, Tada; BASSINGTHWAIGHTE, JAMES B.

    1997-01-01

    Oxygen consumption in small tissue regions cannot be measured directly, but assessment of oxygen transport and metabolism at the regional level is possible with imaging techniques using tracer 15O-oxygen for positron emission tomography. On the premise that mathematical modeling of tracer kinetics is the key to the interpretation of regional concentration-time curves, an axially-distributed capillary-tissue model was developed that accounts for oxygen convection in red blood cells and plasma,...

  15. High dose Erythropoietin increases Brain Tissue Oxygen Tension in Severe Vasospasm after Subarachnoid Hemorrhage

    Directory of Open Access Journals (Sweden)

    Helbok Raimund

    2012-06-01

    Full Text Available Abstract Background Vasospasm-related delayed cerebral ischemia (DCI significantly impacts on outcome after aneurysmal subarachnoid hemorrhage (SAH. Erythropoietin (EPO may reduce the severity of cerebral vasospasm and improve outcome, however, underlying mechanisms are incompletely understood. In this study, the authors aimed to investigate the effect of EPO on cerebral metabolism and brain tissue oxygen tension (PbtO2. Methods Seven consecutive poor grade SAH patients with multimodal neuromonitoring (MM received systemic EPO therapy (30.000 IU per day for 3 consecutive days for severe cerebral vasospasm. Cerebral perfusion pressure (CPP, mean arterial blood pressure (MAP, intracranial pressure (ICP, PbtO2 and brain metabolic changes were analyzed during the next 24 hours after each dose given. Statistical analysis was performed with a mixed effects model. Results A total of 22 interventions were analyzed. Median age was 47 years (32–68 and 86 % were female. Three patients (38 % developed DCI. MAP decreased 2 hours after intervention (P btO2 significantly increased over time (P  Conclusions EPO increases PbtO2 in poor grade SAH patients with severe cerebral vasospasm. The effect on outcome needs further investigation.

  16. Persistent resetting of the cerebral oxygen/glucose uptake ratio by brain activation

    DEFF Research Database (Denmark)

    Madsen, P L; Hasselbalch, S G; Hagemann, L P; Olsen, K S; Bülow, J; Holm, S; Wildschiødtz, Gordon; Paulson, O B; Lassen, N A

    1995-01-01

    showed that the activation-induced resetting of the relation between CMRglc and CMRO2 persisted virtually unaltered for > or = 40 min after the mental activation task was terminated. The activation-induced increase in cerebral lactate efflux measured over the same time period accounted for only a small......Global cerebral blood flow (CBF), global cerebral metabolic rates for oxygen (CMRO2), and for glucose (CMRglc), and lactate efflux were measured during rest and during cerebral activation induced by the Wisconsin card sorting test. Measurements were performed in healthy volunteers using the Kety...... stress indicators returned to baseline values. Activation-induced resetting of the cerebral oxygen/glucose uptake ratio is not necessarily accounted for by increased lactate production from nonoxidative glucose metabolism....

  17. High-spatial-resolution mapping of the oxygen concentration in cortical tissue (Conference Presentation)

    Science.gov (United States)

    Jaswal, Rajeshwer S.; Yaseen, Mohammad A.; Fu, Buyin; Boas, David A.; Sakadžic, Sava

    2016-03-01

    Due to a lack of imaging tools for high-resolution imaging of cortical tissue oxygenation, the detailed maps of the oxygen partial pressure (PO2) around arterioles, venules, and capillaries remain largely unknown. Therefore, we have limited knowledge about the mechanisms that secure sufficient oxygen delivery in microvascular domains during brain activation, and provide some metabolic reserve capacity in diseases that affect either microvascular networks or the regulation of cerebral blood flow (CBF). To address this challenge, we applied a Two-Photon PO2 Microscopy to map PO2 at different depths in mice cortices. Measurements were performed through the cranial window in the anesthetized healthy mice as well as in the mouse models of microvascular dysfunctions. In addition, microvascular morphology was recorded by the two-photon microscopy at the end of each experiment and subsequently segmented. Co-registration of the PO2 measurements and exact microvascular morphology enabled quantification of the tissue PO2 dependence on distance from the arterioles, capillaries, and venules at various depths. Our measurements reveal significant spatial heterogeneity of the cortical tissue PO2 distribution that is dominated by the high oxygenation in periarteriolar spaces. In cases of impaired oxygen delivery due to microvascular dysfunction, significant reduction in tissue oxygenation away from the arterioles was observed. These tissue domains may be the initial sites of cortical injury that can further exacerbate the progression of the disease.

  18. Near-infrared spectroscopy determined cerebral oxygenation with eliminated skin blood flow in young males

    DEFF Research Database (Denmark)

    Hirasawa, Ai; Kaneko, Takahito; Tanaka, Naoki; Funane, Tsukasa; Kiguchi, Masashi; Sørensen, Henrik; Secher, Niels H; Ogoh, Shigehiko

    2016-01-01

    We estimated cerebral oxygenation during handgrip exercise and a cognitive task using an algorithm that eliminates the influence of skin blood flow (SkBF) on the near-infrared spectroscopy (NIRS) signal. The algorithm involves a subtraction method to develop a correction factor for each subject......-detector distances (15 and 30 mm) with the algorithm using the individual correction factor, we expressed cerebral oxygenation without influence from scalp and scull blood flow. Validity of the estimated cerebral oxygenation was verified during cerebral neural activation (handgrip exercise and cognitive task). With...... pressure was applied to the temporal artery, estimated O2Hb was not affected by elimination of SkBF during handgrip exercise (P = 0.666) or the cognitive task (P = 0.105). These findings suggest that the algorithm with the individual correction factor allows for evaluation of changes in an accurate...

  19. Mapping of cerebral metabolic rate of oxygen using dynamic susceptibility contrast and blood oxygen level dependent MR imaging in acute ischemic stroke

    International Nuclear Information System (INIS)

    MR-derived cerebral metabolic rate of oxygen utilization (CMRO2) has been suggested to be analogous to PET-derived CMRO2 and therefore may be used for detection of viable tissue at risk for infarction. The purpose of this study was to evaluate MR-derived CMRO2 mapping in acute ischemic stroke in relation to established diffusion- and perfusion-weighted imaging. In 23 patients (mean age 63 ± 18.7 years, 11 women) with imaging findings for acute ischemic stroke, relative oxygen extraction fraction was calculated from quantitative transverse relaxation times (T2, T2*) and relative cerebral blood volume using a quantitative blood oxygenation level dependent (BOLD) approach in order to detect a local increase of deoxyhemoglobin. Relative CMRO2 (rCMRO2) maps were calculated by multiplying relative oxygen extraction fraction (rOEF) by cerebral blood flow, derived from PWI. After co-registration, rCMRO2 maps were evaluated in comparison with apparent diffusion coefficient (ADC) and time-to-peak (TTP) maps. Mean rCMRO2 values in areas with diffusion-restriction or TTP/ADC mismatch were compared with rCMRO2 values in the contralateral tissue. In tissue with diffusion restriction, mean rCMRO2 values were significantly decreased compared to perfusion-impaired (17.9 [95 % confidence interval 10.3, 25.0] vs. 58.1 [95 % confidence interval 50.1, 70.3]; P < 0.001) and tissue in the contralateral hemisphere (68.2 [95 % confidence interval 61.4, 75.0]; P < 0.001). rCMRO2 in perfusion-impaired tissue showed no significant change compared to tissue in the contralateral hemisphere (58.1 [95 % confidence interval 50.1, 70.3] vs. 66.7 [95 % confidence interval 53.4, 73.4]; P = 0.34). MR-derived CMRO2 was decreased within diffusion-restricted tissue and stable within perfusion-impaired tissue, suggesting that this technique may be adequate to reveal different pathophysiological stages in acute stroke. (orig.)

  20. Mapping of cerebral metabolic rate of oxygen using dynamic susceptibility contrast and blood oxygen level dependent MR imaging in acute ischemic stroke

    Energy Technology Data Exchange (ETDEWEB)

    Gersing, Alexandra S.; Schwaiger, Benedikt J. [Technical University Munich, Klinikum rechts der Isar, Department of Neuroradiology, Munich (Germany); University of California, Department of Radiology and Biomedical Imaging, San Francisco, CA (United States); Ankenbrank, Monika; Toth, Vivien; Bauer, Jan S.; Zimmer, Claus [Technical University Munich, Klinikum rechts der Isar, Department of Neuroradiology, Munich (Germany); Janssen, Insa [Technical University Munich, Department of Neurosurgery, Munich (Germany); Kooijman, Hendrik [Philips Healthcare, Hamburg (Germany); Wunderlich, Silke [Technical University Munich, Department of Neurology, Munich (Germany); Preibisch, Christine [Technical University Munich, Klinikum rechts der Isar, Department of Neuroradiology, Munich (Germany); Technical University Munich, Department of Neurology, Munich (Germany)

    2015-12-15

    MR-derived cerebral metabolic rate of oxygen utilization (CMRO{sub 2}) has been suggested to be analogous to PET-derived CMRO{sub 2} and therefore may be used for detection of viable tissue at risk for infarction. The purpose of this study was to evaluate MR-derived CMRO{sub 2} mapping in acute ischemic stroke in relation to established diffusion- and perfusion-weighted imaging. In 23 patients (mean age 63 ± 18.7 years, 11 women) with imaging findings for acute ischemic stroke, relative oxygen extraction fraction was calculated from quantitative transverse relaxation times (T2, T2*) and relative cerebral blood volume using a quantitative blood oxygenation level dependent (BOLD) approach in order to detect a local increase of deoxyhemoglobin. Relative CMRO{sub 2} (rCMRO{sub 2}) maps were calculated by multiplying relative oxygen extraction fraction (rOEF) by cerebral blood flow, derived from PWI. After co-registration, rCMRO{sub 2} maps were evaluated in comparison with apparent diffusion coefficient (ADC) and time-to-peak (TTP) maps. Mean rCMRO{sub 2} values in areas with diffusion-restriction or TTP/ADC mismatch were compared with rCMRO{sub 2} values in the contralateral tissue. In tissue with diffusion restriction, mean rCMRO{sub 2} values were significantly decreased compared to perfusion-impaired (17.9 [95 % confidence interval 10.3, 25.0] vs. 58.1 [95 % confidence interval 50.1, 70.3]; P < 0.001) and tissue in the contralateral hemisphere (68.2 [95 % confidence interval 61.4, 75.0]; P < 0.001). rCMRO{sub 2} in perfusion-impaired tissue showed no significant change compared to tissue in the contralateral hemisphere (58.1 [95 % confidence interval 50.1, 70.3] vs. 66.7 [95 % confidence interval 53.4, 73.4]; P = 0.34). MR-derived CMRO{sub 2} was decreased within diffusion-restricted tissue and stable within perfusion-impaired tissue, suggesting that this technique may be adequate to reveal different pathophysiological stages in acute stroke. (orig.)

  1. Near-infrared spectroscopy determined cerebral oxygenation with eliminated skin blood flow in young males.

    Science.gov (United States)

    Hirasawa, Ai; Kaneko, Takahito; Tanaka, Naoki; Funane, Tsukasa; Kiguchi, Masashi; Sørensen, Henrik; Secher, Niels H; Ogoh, Shigehiko

    2016-04-01

    We estimated cerebral oxygenation during handgrip exercise and a cognitive task using an algorithm that eliminates the influence of skin blood flow (SkBF) on the near-infrared spectroscopy (NIRS) signal. The algorithm involves a subtraction method to develop a correction factor for each subject. For twelve male volunteers (age 21 ± 1 yrs) +80 mmHg pressure was applied over the left temporal artery for 30 s by a custom-made headband cuff to calculate an individual correction factor. From the NIRS-determined ipsilateral cerebral oxyhemoglobin concentration (O2Hb) at two source-detector distances (15 and 30 mm) with the algorithm using the individual correction factor, we expressed cerebral oxygenation without influence from scalp and scull blood flow. Validity of the estimated cerebral oxygenation was verified during cerebral neural activation (handgrip exercise and cognitive task). With the use of both source-detector distances, handgrip exercise and a cognitive task increased O2Hb (P cognitive task (P = 0.105). These findings suggest that the algorithm with the individual correction factor allows for evaluation of changes in an accurate cerebral oxygenation without influence of extracranial blood flow by NIRS applied to the forehead. PMID:26018458

  2. Regional cerebral oxygen saturation in newborn infants in the first 15 min of life after vaginal delivery

    International Nuclear Information System (INIS)

    The objective of this study was to evaluate regional oxygen saturation of the brain during immediate transition after birth, and to correlate it with pre-ductal arterial oxygen saturation in newborn infants. The prospective observational study including newborn infants in the first 15 min after spontaneous vaginal delivery and uncomplicated transitional period was undertaken. Regional cerebral oxygen saturation (rSO2brain) was measured using near-infrared spectroscopy. Arterial oxygen saturation (SpO2) and heart rate (HR) were measured on the right wrist by pulse oximetry. rSO2brain, SpO2 and HR measurements were started immediately after birth and were performed in the first 15 min of life. Cerebral fractional tissue oxygen extraction (FTOE) was calculated for each minute. Of 145 newborn infants, 16 were included and the gender allocation was 31 females (49.2%) and 32 males (50.8%). rSO2brain increased rapidly from 39% (2 min) to 69% (5 min), SpO2 increased from 72% (2 min) to 96% (14 min) and FTOE showed a significant decrease from minute 2 (0.47) until minute 4 (0.30) and an increase between 8 to 13 min. rSO2brain increased rapidly after vaginal delivery. Although SpO2 increased within the first 14 min after delivery, rSO2brain showed no further significant changes after 5 min. FTOE decreased in the first 4 min and reached standard values subsequently. (paper)

  3. Linear coupling between cerebral blood flow and oxygen consumption in activated human cortex

    OpenAIRE

    Richard D. Hoge; Atkinson, Jeff; Gill, Brad; Crelier, Gérard R.; Marrett, Sean; Pike, G Bruce

    1999-01-01

    The aim of this study was to test the hypothesis that, within a specific cortical unit, fractional changes in cerebral blood flow (CBF) and cerebral metabolic rate of oxygen consumption (CMRO2) are coupled through an invariant relationship during physiological stimulation. This aim was achieved by simultaneously measuring relative changes in these quantities in human primary visual cortex (V1) during graded stimulation with patterns designed to selectively activate different populations of V1...

  4. Hyperbaric Oxygen for Cerebral Vasospasm and Brain Injury Following Subarachnoid Hemorrhage

    OpenAIRE

    Ostrowski, Robert P.; Zhang, John H.

    2011-01-01

    The impact of acute brain injury and delayed neurological deficits due to cerebral vasospasm (CVS) are major determinants of outcomes after subarachnoid hemorrhage (SAH). Although hyperbaric oxygen (HBO) had been used to treat patients with SAH, the supporting evidence and underlying mechanisms have not been systematically reviewed. In the present paper, the overview of studies of HBO for cerebral vasospasm is followed by a discussion of HBO molecular mechanisms involved in the protection aga...

  5. Evaluation of near infrared spectroscopy for detecting the β blocker-induced decrease in cerebral oxygenation during hemodilution in a swine model.

    Science.gov (United States)

    Kurita, Tadayoshi; Morita, Koji; Sato, Shigehito

    2015-12-01

    β blockers reduce cerebral oxygenation after acute hemodilution and may contribute to the incidence of stroke when used perioperatively. The goal of the study was to investigate whether cerebral tissue oxygenation using near infrared spectroscopy can detect the β blocker-induced decrease in cerebral oxygenation depending on the severity of hemodilution and/or the dose of β blockers. Animals were anesthetized with 2% isoflurane and randomly assigned to a landiolol or esmolol group. After baseline measurement, landiolol or esmolol was administered at 40 µg/kg/min for 20 min, increased to 200 µg/kg/min for 20 min, and then stopped. Hemodynamic and arterial variables and the tissue oxygenation index (TOI) were recorded at each β blocker dose. Two stages of hemodilution were sequentially induced by repeated hemorrhage of 600 ml (33% of estimated blood volume) and infusion of the same volume of hydroxyethylstarch. During each stage, landiolol or esmolol was similarly administered and measurements were made. Landiolol and esmolol both dose-dependently decreased heart rate, mean arterial pressure and cardiac output, depending on the severity of hemodilution. Landiolol at 40 µg/kg/min was almost equivalent in potency to 200 µg/kg/min esmolol for decreasing HR before hemodilution. Based on the TOI, short-acting β blockers reduced cerebral oxygenation in a dose-dependent manner during hemodilution, and oxygenation returned to the baseline level after drug infusion was stopped. TOI may be useful for identification of a decrease in cerebral oxygenation for patients receiving β blockade during surgery associated with major bleeding. PMID:25876017

  6. Microcirculatory dysfunction and tissue oxygenation in critical illness.

    Science.gov (United States)

    Østergaard, L; Granfeldt, A; Secher, N; Tietze, A; Iversen, N K; Jensen, M S; Andersen, K K; Nagenthiraja, K; Gutiérrez-Lizardi, P; Mouridsen, K; Jespersen, S N; Tønnesen, E K

    2015-11-01

    Severe sepsis is defined by organ failure, often of the kidneys, heart, and brain. It has been proposed that inadequate delivery of oxygen, or insufficient extraction of oxygen in tissue, may explain organ failure. Despite adequate maintenance of systemic oxygen delivery in septic patients, their morbidity and mortality remain high. The assumption that tissue oxygenation can be preserved by maintaining its blood supply follows from physiological models that only apply to tissue with uniformly perfused capillaries. In sepsis, the microcirculation is profoundly disturbed, and the blood supply of individual organs may therefore no longer reflect their access to oxygen. We review how capillary flow patterns affect oxygen extraction efficacy in tissue, and how the regulation of tissue blood flow must be adjusted to meet the metabolic needs of the tissue as capillary flows become disturbed as observed in critical illness. Using the brain, heart, and kidney as examples, we discuss whether disturbed capillary flow patterns might explain the apparent mismatch between organ blood flow and organ function in sepsis. Finally, we discuss diagnostic means of detecting capillary flow disturbance in animal models and in critically ill patients, and address therapeutic strategies that might improve tissue oxygenation by modifying capillary flow patterns. PMID:26149711

  7. Cerebral perfusion, oxygenation and metabolism during exercise in young and elderly individuals

    DEFF Research Database (Denmark)

    Fisher, James P; Hartwich, Doreen; Seifert, Thomas;

    2013-01-01

    artery blood velocity (MCA V(mean)), mean arterial pressure (MAP), cardiac output (CO) and the partial pressure of arterial carbon dioxide (PaCO(2)) were measured. Blood samples were obtained from the right internal jugular vein and brachial artery to determine concentration differences for oxygen (O(2......We evaluated cerebral perfusion, oxygenation, and metabolism in eleven young (age 22 ± 1 years) and nine older (age 66 ± 2 years) individuals at rest and during cycling exercise at low (25% W(max)), moderate (50% W(max)), high (75% W(ma)) and exhaustive (100% W(max)) workloads. Mean middle cerebral...

  8. Blood flow and oxygenation changes due to low-frequency repetitive transcranial magnetic stimulation of the cerebral cortex

    Science.gov (United States)

    Mesquita, Rickson C.; Faseyitan, Olufunsho K.; Turkeltaub, Peter E.; Buckley, Erin M.; Thomas, Amy; Kim, Meeri N.; Durduran, Turgut; Greenberg, Joel H.; Detre, John A.; Yodh, Arjun G.; Hamilton, Roy H.

    2013-06-01

    Transcranial magnetic stimulation (TMS) modulates processing in the human brain and is therefore of interest as a treatment modality for neurologic conditions. During TMS administration, an electric current passing through a coil on the scalp creates a rapidly varying magnetic field that induces currents in the cerebral cortex. The effects of low-frequency (1 Hz), repetitive TMS (rTMS) on motor cortex cerebral blood flow (CBF) and tissue oxygenation in seven healthy adults, during/after 20 min stimulation, is reported. Noninvasive optical methods are employed: diffuse correlation spectroscopy (DCS) for blood flow and diffuse optical spectroscopy (DOS) for hemoglobin concentrations. A significant increase in median CBF (33%) on the side ipsilateral to stimulation was observed during rTMS and persisted after discontinuation. The measured hemodynamic parameter variations enabled computation of relative changes in cerebral metabolic rate of oxygen consumption during rTMS, which increased significantly (28%) in the stimulated hemisphere. By contrast, hemodynamic changes from baseline were not observed contralateral to rTMS administration (all parameters, p>0.29). In total, these findings provide new information about hemodynamic/metabolic responses to low-frequency rTMS and, importantly, demonstrate the feasibility of DCS/DOS for noninvasive monitoring of TMS-induced physiologic effects.

  9. Effect of propofol and remifentanil on cerebral perfusion and oxygenation in pigs: a systematic review.

    Science.gov (United States)

    Mikkelsen, Mai Louise Grandsgaard; Ambrus, Rikard; Miles, James Edward; Poulsen, Helle Harding; Moltke, Finn Borgbjerg; Eriksen, Thomas

    2016-01-01

    The objective of this review is to evaluate the existing literature with regard to the influence of propofol and remifentanil total intravenous anaesthesia (TIVA) on cerebral perfusion and oxygenation in healthy pigs. Anaesthesia has influence on cerebral haemodynamics and it is important not only in human but also in veterinary anaesthesia to preserve optimal regulation of cerebral haemodynamics. Propofol and remifentanil are widely used in neuroanaesthesia and are increasingly used in experimental animal studies. In translational models, the pig has advantages compared to small laboratory animals because of brain anatomy, metabolism, neurophysiological maturation, and cerebral haemodynamics. However, reported effects of propofol and remifentanil on cerebral perfusion and oxygenation in pigs have not been reviewed. An electronic search identified 99 articles in English. Title and abstract screening selected 29 articles for full-text evaluation of which 19 were excluded with reasons. Of the 10 peer-reviewed articles included for review, only three had propofol or remifentanil anaesthesia as the primary study objective and only two directly investigated the effect of anaesthesia on cerebral perfusion and oxygenation (CPO). The evidence evaluated in this systematic review is limited, not focused on propofol and remifentanil and possibly influenced by factors of potential importance for CPO assessment. In one study of healthy pigs, CPO measures were within normal ranges following propofol-remifentanil anaesthesia, and addition of a single remifentanil bolus did not affect regional cerebral oxygen saturation (rSO2). Even though the pool of evidence suggests that propofol and remifentanil alone or in combination have limited effects on CPO in healthy pigs, confirmative evidence is lacking. PMID:27334375

  10. Low oxygen concentrations impair tissue development in tissue-engineered cardiovascular constructs

    NARCIS (Netherlands)

    Vlimmeren, M.A.A. van; Driessen-Mol, A.; Oomens, C.W.J.; Broek, M. van den; Stoop, R.; Bouten, C.V.C.; Baaijens, F.P.T.

    2012-01-01

    Cardiovascular tissue engineering has shown considerable progress, but in vitro tissue conditioning to stimulate the development of a functional extracellular matrix still needs improvement. We investigated the environmental factor oxygen concentration for its potential to increase the amount of col

  11. The evaluation of cerebral oxygenation by oximetry in patients with ischaemic stroke.

    Directory of Open Access Journals (Sweden)

    Demet G

    2000-04-01

    Full Text Available AIMS: To evaluate the clinical significance of estimation of the regional cerebral oxygen saturation (rSO2 in the patients with ischaemic stroke by the cerebral oximetry during acute, sub-acute and chronic phases. SUBJECTS AND METHODS: In this prospective study, 24 patients with ischaemic stroke in the middle cerebral artery territory were included. A detailed clinical examination and appropriate laboratory investigations were carried out. The rSO2 was determined by oximetery (INVOS 3100-SD bilaterally on the first, third, seventh, and fifteenth days. The blood pressure, the peripheral capillary oxygen saturation and the arterial blood gas values were noted too. the changes were evaluated along with Glasgow coma scale (GCS using unpaired student t-test and one way ANOVA test. RESULTS: There were significant differences between the rSO2 values in acute, subacute and chronic phases on the side of the lesion (p value < 0.05. The values of oxygen saturation gradually increased throughout the chronic phase. These values showed a positive correlation with GCS, but the results were not significant statistically. The rSO2 values were also significantly higher on the non-lesional side than those on the lesion side in the acute phase (p= 0.0034, the discrepancy disappeared during the sub-acute and chronic phases. CONCLUSION: Cerebral oximetry can be used as a measure to evaluate the cerebral oxygenation during the various phases of ischaemic stroke. It has a potential to serve as a useful marker for detection of cerebral oxygenation imbalances, to judge the effectiveness of the management and for the follow-up of patients with ischaemic stroke.

  12. Statistical mapping of effects of middle cerebral artery occlusion (MCAO) on blood flow and oxygen consumption in porcine brain.

    Science.gov (United States)

    Watanabe, Hideaki; Sakoh, Masaharu; Andersen, Flemming; Rodell, Anders; Sørensen, Jens Christian; Østergaard, Leif; Mouridsen, Kim; Cumming, Paul

    2007-02-15

    The volume of cerebral tissue perturbed in experimental models of middle cerebral artery occlusion (MCAO) can be highly variable. Thus, the territories of reduced cerebral blood flow (CBF) or oxygen consumption (CMRO(2)) following MCAO might properly be defined using statistical parametric mapping within a population. In order to establish such a method, we mapped CBF and CMRO(2) in 18 pigs with acute MCAO. Parametric maps were flipped about the axis of symmetry, and CBF and CMRO(2) in the infarcted hemisphere were calculated as percentages of the magnitudes in mirror-image pixels. There were log-linear relationships between the volumes of affected tissue and the percentages of normal CFB or CMRO(2). This graphical analysis showed that the volume of the core deficit was smaller for CBF that for CMRO(2), but expanded more rapidly with decreasing CBF deficit than did the corresponding volumes of reduced CMRO(2). Thus, acute changes in CBF and CMRO(2) following MCAO in the pig can be defined as probabilistic volumes. PMID:17129609

  13. Sanguinate's effect on pial arterioles in healthy rats and cerebral oxygen tension after controlled cortical impact.

    Science.gov (United States)

    Mullah, Saad H; Abutarboush, Rania; Moon-Massat, Paula F; Saha, Biswajit K; Haque, Ashraful; Walker, Peter B; Auker, Charles R; Arnaud, Francoise G; McCarron, Richard M; Scultetus, Anke H

    2016-09-01

    Sanguinate, a polyethylene glycol-conjugated carboxyhemoglobin, was investigated for cerebral vasoactivity in healthy male Sprague-Dawley rats (Study 1) and for its ability to increase brain tissue oxygen pressure (PbtO2) after controlled cortical impact (CCI) - traumatic brain injury (TBI) (Study 2). In both studies ketamine-acepromazine anesthetized rats were ventilated with 40% O2. In Study 1, a cranial window was used to measure the diameters of medium - (50-100μm) and small-sized (volume-matched Hextend, or normal saline. In Study 2, PbtO2 was measured using a phosphorescence quenching method before TBI, 15min after TBI (T15) and then every 10min thereafter for 155min. At T15, rats received either 8mL/kg IV Sanguinate (40mL/kg/h) or no treatment (saline, 4mL/kg/h). Results showed: 1) in healthy rats, percentage changes in pial arteriole diameter were the same among the groups, 2) in TBI rats, PbtO2 decreased from 36.5±3.9mmHg to 19.8±3.0mmHg at T15 in both groups after TBI and did not recover in either group for the rest of the study, and 3) MAP increased 16±4mmHg and 36±5mmHg after Sanguinate in healthy and TBI rats, respectively, while MAP was unchanged in control groups. In conclusion, Sanguinate did not cause vasoconstriction in the cerebral pial arterioles of healthy rats but it also did not acutely increase PbtO2 when administered after TBI. Sanguinate was associated with an increase in MAP in both studies. PMID:27287870

  14. Buyanghuanwu decoction promotes angiogenesis after cerebral ischemia/reperfusion injury: mechanisms of brain tissue repair.

    Science.gov (United States)

    Zhang, Zhen-Qiang; Song, Jun-Ying; Jia, Ya-Quan; Zhang, Yun-Ke

    2016-03-01

    Buyanghuanwu decoction has been shown to protect against cerebral ischemia/reperfusion injury, but the underlying mechanisms remain unclear. In this study, rats were intragastrically given Buyanghuanwu decoction, 15 mL/kg, for 3 days. A rat model of cerebral ischemia/reperfusion injury was established by middle cerebral artery occlusion. In rats administered Buyanghuanwu decoction, infarct volume was reduced, serum vascular endothelial growth factor and integrin αvβ3 levels were increased, and brain tissue vascular endothelial growth factor and CD34 expression levels were increased compared with untreated animals. These effects of Buyanghuanwu decoction were partially suppressed by an angiogenesis inhibitor (administered through the lateral ventricle for 7 consecutive days). These data suggest that Buyanghuanwu decoction promotes angiogenesis, improves cerebral circulation, and enhances brain tissue repair after cerebral ischemia/reperfusion injury. PMID:27127482

  15. Buyanghuanwu decoction promotes angiogenesis after cerebral ischemia/reperfusion injury:mechanisms of brain tissue repair

    Institute of Scientific and Technical Information of China (English)

    Zhen-qiang Zhang; Jun-ying Song; Ya-quan Jia; Yun-ke Zhang

    2016-01-01

    Buyanghuanwu decoction has been shown to protect against cerebral ischemia/reperfusion injury, but the underlying mechanisms remain unclear. In this study, rats were intragastrically givenBuyanghuanwu decoction, 15 mL/kg, for 3 days. A rat model of cerebral ischemia/reper-fusion injury was established by middle cerebral artery occlusion. In rats administeredBuyanghuanwu decoction, infarct volume was reduced, serum vascular endothelial growth factor and integrinαvβ3 levels were increased, and brain tissue vascular endothelial growth factor and CD34 expression levels were increased compared with untreated animals. These effects ofBuyanghuanwu decoction were partially suppressed by an angiogenesis inhibitor (administered through the lateral ventricle for 7 consecutive days). These data suggest thatBuyanghuanwu de-coction promotes angiogenesis, improves cerebral circulation, and enhances brain tissue repair after cerebral ischemia/reperfusion injury.

  16. Buyanghuanwu decoction promotes angiogenesis after cerebral ischemia/reperfusion injury: mechanisms of brain tissue repair

    Directory of Open Access Journals (Sweden)

    Zhen-qiang Zhang

    2016-01-01

    Full Text Available Buyanghuanwu decoction has been shown to protect against cerebral ischemia/reperfusion injury, but the underlying mechanisms remain unclear. In this study, rats were intragastrically given Buyanghuanwu decoction, 15 mL/kg, for 3 days. A rat model of cerebral ischemia/reperfusion injury was established by middle cerebral artery occlusion. In rats administered Buyanghuanwu decoction, infarct volume was reduced, serum vascular endothelial growth factor and integrin αvβ3 levels were increased, and brain tissue vascular endothelial growth factor and CD34 expression levels were increased compared with untreated animals. These effects of Buyanghuanwu decoction were partially suppressed by an angiogenesis inhibitor (administered through the lateral ventricle for 7 consecutive days. These data suggest that Buyanghuanwu decoction promotes angiogenesis, improves cerebral circulation, and enhances brain tissue repair after cerebral ischemia/reperfusion injury.

  17. Factors affecting cerebral oxygenation in hemodialysis patients: cerebral oxygenation associates with pH, hemodialysis duration, serum albumin concentration, and diabetes mellitus.

    Directory of Open Access Journals (Sweden)

    Kiyonori Ito

    Full Text Available Patients undergoing hemodialysis (HD often develop cerebral disease complications. Furthermore, cerebral regional saturation of oxygen (rSO2 was previously reported to be significantly lower in HD patients than in healthy subjects. We aimed to identify the factors affecting the cerebral rSO2 in HD patients.Fifty-four HD patients (38 men and 16 women; mean age, 67.7 ± 1.2 years, HD duration, 6.5 ± 1.9 years were recruited. Cerebral rSO2 was monitored at the forehead before HD using an INVOS 5100C (Covidien Japan, Tokyo, Japan.The rSO2 levels were significantly lower in HD patients compared with healthy controls (49.5 ± 1.7% vs. 68.9 ± 1.6%, p <0.001. Multiple regression analysis showed that cerebral rSO2 independently associated with pH (standardized coefficient: -0.35, HD duration (standardized coefficient: -0.33, and serum albumin concentration (standardized coefficient: 0.28. Furthermore, the rSO2 was significantly lower in HD patients with diabetes mellitus (DM, compared with patients without DM (46.8 ± 1.7% vs. 52.1 ± 1.8%, p <0.05.In HD patients, cerebral rSO2 was affected by multiple factors, including pH, HD duration, and serum albumin concentration. Furthermore, this is the first report describing significantly lower levels of rSO2 in HD patients with DM than in those without DM.

  18. Renal Tissue Oxygenation in Essential Hypertension and Chronic Kidney Disease

    OpenAIRE

    Menno Pruijm; Lucie Hofmann; Bruno Vogt; Marie-Eve Muller; Maciej Piskunowicz; Matthias Stuber; Michel Burnier

    2013-01-01

    Animal studies suggest that renal tissue hypoxia plays an important role in the development of renal damage in hypertension and renal diseases, yet human data were scarce due to the lack of noninvasive methods. Over the last decade, blood oxygenation level-dependent magnetic resonance imaging (BOLD-MRI), detecting deoxyhemoglobin in hypoxic renal tissue, has become a powerful tool to assess kidney oxygenation noninvasively in humans. This paper provides an overview of BOLD-MRI studies perform...

  19. Cerebral blood flow, oxygen and glucose metabolism with PET in progressive supranuclear palsy

    Energy Technology Data Exchange (ETDEWEB)

    Otsuka, Makoto; Ichiya, Yuici; Kuwabara, Yasuo (Kyushu Univ., Fukuoka (Japan). Faculty of Medicine) (and others)

    1989-11-01

    Cerebral blood flow, cerebral oxygen metabolic rate and cerebral glucose metabolic rate were measured with positron emission tomography (PET) in four patients with progressive supranuclear palsy (PSP). Decreased blood flow and hypometabolism of oxygen and glucose were found in both subcortical and cortical regions, particularly in the striatum including the head of the caudate nucleus and the frontal cortex. The coupling between blood flow and metabolism was preserved even in the regions which showed decreased blood flow and hypometabolism. These findings indicated the hypofunction, as revealed by decreased blood flow and hypometablolism on PET, both in the striatum and the frontal cortex, and which may underlie the pathophysiological mechanism of motor and mental disturbance in PSP. (author).

  20. Cerebral blood flow, oxygen and glucose metabolism with PET in progressive supranuclear palsy

    International Nuclear Information System (INIS)

    Cerebral blood flow, cerebral oxygen metabolic rate and cerebral glucose metabolic rate were measured with positron emission tomography (PET) in four patients with progressive supranuclear palsy (PSP). Decreased blood flow and hypometabolism of oxygen and glucose were found in both subcortical and cortical regions, particularly in the striatum including the head of the caudate nucleus and the frontal cortex. The coupling between blood flow and metabolism was preserved even in the regions which showed decreased blood flow and hypometabolism. These findings indicated the hypofunction, as revealed by decreased blood flow and hypometablolism on PET, both in the striatum and the frontal cortex, and which may underlie the pathophysiological mechanism of motor and mental disturbance in PSP. (author)

  1. Marked reduction of cerebral oxygen metabolism in patients with advanced cirrhosis; A positron emission tomography study

    Energy Technology Data Exchange (ETDEWEB)

    Kawatoko, Toshiharu; Murai, Koichiro; Ibayashi, Setsurou; Tsuji, Hiroshi; Nomiyama, Kensuke; Sadoshima, Seizo; Eujishima, Masatoshi; Kuwabara, Yasuo; Ichiya, Yuichi (Kyushu Univ., Fukuoka (Japan). Faculty of Medicine)

    1992-01-01

    Regional cerebral blood flow (rCBF), cerebral metabolic rate of oxygen (rCMRO{sub 2}), and oxygen extraction fraction (rOEF) were measured using positron emission tomography (PET) in four patients with cirrhosis (two males and two females, aged 57 to 69 years) in comparison with those in five age matched controls with previous transient global amnesia. PET studies were carried out when the patients were fully alert and oriented after the episodes of encephalopathy. In the patients, rCBF tended to be lower, while rCMRO{sub 2} was significantly lowered in almost all hemisphere cortices, more markedly in the frontal cortex. Our results suggest that the brain oxygen metabolism is diffusely impaired in patients with advanced cirrhosis, and the frontal cortex seems to be more susceptible to the systemic metabolic derangements induced by chronic liver disease. (author).

  2. Marked reduction of cerebral oxygen metabolism in patients with advanced cirrhosis

    International Nuclear Information System (INIS)

    Regional cerebral blood flow (rCBF), cerebral metabolic rate of oxygen (rCMRO2), and oxygen extraction fraction (rOEF) were measured using positron emission tomography (PET) in four patients with cirrhosis (two males and two females, aged 57 to 69 years) in comparison with those in five age matched controls with previous transient global amnesia. PET studies were carried out when the patients were fully alert and oriented after the episodes of encephalopathy. In the patients, rCBF tended to be lower, while rCMRO2 was significantly lowered in almost all hemisphere cortices, more markedly in the frontal cortex. Our results suggest that the brain oxygen metabolism is diffusely impaired in patients with advanced cirrhosis, and the frontal cortex seems to be more susceptible to the systemic metabolic derangements induced by chronic liver disease. (author)

  3. Examination of dexamethasone sodium sulfate and hyperbaric oxygenation in experimentally produced cerebral edema

    International Nuclear Information System (INIS)

    Dexamethasone sodium sulfate and hyperbaric oxygenation were used for experimentally produced cerebral edema for the examination of the water content of the brain and cerebrovascular permeability using 203Hg as the tracer. Although dexamethasone starts lowering vascular permeability of the edematous brain at one hour after the intravenous injection, a lapse of 24 hours is required until the water content returns to normal. Although hyperbaric oxygenation dose not reduce cerebrovascular permeability, it brings back the water content of the brain to normal immediately after pressurization. Since the combination of dexamethasone and hyperbaric oxygenation maintains the water content of the brain almost normal throughout the entire process, it is ideal for the treatment of cerebral edema. (Chiba, N.)

  4. Diagnostic efficacy of biophysical tests and cerebral-umbilical index when assessing fetal oxygenation

    Directory of Open Access Journals (Sweden)

    Čančarević-Đajić Branka

    2013-01-01

    Full Text Available Introduction. Perinatal morbidity and mortality are the ultimate indicators of antenatal care today, whose responsible task is to assess the respiratory function of the placenta, fetal growth and placental maturation in order to provide conditions for the delivery of a living and viable newborn. The diagnostic procedures of antenatal care tested within this study were the biophysical tests of cardiotocography and the fetal biophysical profile, along with the colour doppler evaluation of the cerebral-umbilical ratio. The objective of this study was to determine the most effective diagnostic procedure when assessing fetal oxygenation. Materials and Methods. The prospective study included 119 pregnant women. They all underwent cardiotocography, biophysical profile and colour doppler evaluation of the cerebral-umbilical ratio. The babies’ umbilical artery blood pH was determined in the first minute upon birth, along with the Apgar score. Results. The results were processed statistically and the most effective diagnostic procedure for the evaluation of fetal oxygenation was selected, after which the rates of perinatal morbidity and mortality were calculated. The findings revealed that cardiotocography was the most sensitive antepartal predictor of fetal acidosis, while the fetal biophysical profile proved the most specific. The rates of perinatal morbidity and of perinatal mortality were 24.37% and 1.68%, respectively. Conclusion. The findings analysis revealed a high statistical significance of both biophysical tests and the cerebral-umbilical ratio evaluation as predictors of the fetal distress syndrome. The analysis of the cerebral-umbilical ratio and biophysical tests showed that the cerebral-umbilical ratio evaluation not only was more sensitive as a parameter compared to biophysical tests but it was also more specific than cardiotocography. Cardiotocography is the most sensitive antepartal predictor of fetal acidosis, followed by the cerebral

  5. Quantitative measurement of cerebral oxygen extraction fraction using MRI in patients with MELAS.

    Directory of Open Access Journals (Sweden)

    Lei Yu

    Full Text Available OBJECTIVE: To quantify the cerebral OEF at different phases of stroke-like episodes in patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS by using MRI. METHODS: We recruited 32 patients with MELAS confirmed by gene analysis. Conventional MRI scanning, as well as functional MRI including arterial spin labeling and oxygen extraction fraction imaging, was undertaken to obtain the pathological and metabolic information of the brains at different stages of stroke-like episodes in patients. A total of 16 MRI examinations at the acute and subacute phase and 19 examinations at the interictal phase were performed. In addition, 24 healthy volunteers were recruited for control subjects. Six regions of interest were placed in the anterior, middle, and posterior parts of the bilateral hemispheres to measure the OEF of the brain or the lesions. RESULTS: OEF was reduced significantly in brains of patients at both the acute and subacute phase (0.266 ± 0.026 and at the interictal phase (0.295 ± 0.009, compared with normal controls (0.316 ± 0.025. In the brains at the acute and subacute phase of the episode, 13 ROIs were prescribed on the stroke-like lesions, which showed decreased OEF compared with the contralateral spared brain regions. Increased blood flow was revealed in the stroke-like lesions at the acute and subacute phase, which was confined to the lesions. CONCLUSION: MRI can quantitatively show changes in OEF at different phases of stroke-like episodes. The utilization of oxygen in the brain seems to be reduced more severely after the onset of episodes in MELAS, especially for those brain tissues involved in the episodes.

  6. Clinical usefulness of positron emission tomography in the evaluation of regional cerebral blood flow and cerebral oxygen metabolism under glycerol and carbon dioxide loadings

    Energy Technology Data Exchange (ETDEWEB)

    Tanada, Shuji; Yonekura, Yoshiharu; Senda, Michio

    1987-02-01

    Cerebral blood flow (CBF) and oxygen metabolism (CMRO/sub 2/) were studied in normal cerebral cortices by positron emission tomography using continuous inhalation method of oxygen-15 labeled carbon dioxide and oxygen, and single inhalation method of oxygen-15 labeled carbon monoxide. The values of CBF, CMRO/sub 2/, and oxygen extraction fraction (OEF) in cerebral cortices of 18 healthy normal volunteers represented 40 +- 7 ml/100 ml/min, 3.2 +- 0.5 ml O/sub 2//100 ml/min, and 0.43 +- 0.07, respectively. In cases with glycerol loading, CBF increased in 10/14 cases. Studies of 6 cases with intracranial pressure indicated the presence of mechanism by which depressed CMRO/sub 2/ improved and was kept in normal values. The loading of 5% carbon dioxide showed an increase in CBF in cases with cerebral infarction, which implied the good cerebral vascular response to the elevated arterial carbon dioxide, but no particular changes were observed in CMRO/sub 2/ which seemed to be less responsive to the elevated arterial carbon dioxide level. In cases with moyamoya disease, 5% carbon dioxide loading showed no changes in CBF and CMRO/sub 2/. This suggested the poor cerebral vascular response to the elevation of arterial carbon dioxide, while X-ray CT failed to demonstrate any abnormalities in corresponding areas. Positron emission tomography proved to have a great potentiality regarding the evaluation of the changes in cerebral blood flow and cerebral oxygen metabolism under various loadings.

  7. Oxygen radical microscopy in living plant tissues

    DEFF Research Database (Denmark)

    Kristiansen, Kim Anker; Møller, Ian Max; Schulz, Alexander

    nonphotosynthesizing plants the ROS production stems from the mitochondria and peroxisomes as is seen in animal cells. At the Bioimaging Center at KVL we employ different techniques to induce, detect and monitor ROS production, distribution and in and among living plant cells. Both confocal laser scanning microscopy......Reactive oxygen species (ROS) play a crucial role in a wide variety of processes. Initiation of many different cellular pathways, crosstalk between cells, developmental signalling in planta, programmed cell death and hypersensitive response in connection with plant-pathogen interactions are among...... the different roles ROS play. On the other hand ROS also cause damage to cellular components at sub-lethal to lethal levels. In photosynthesizing plants the major production of ROS origin from the chloroplast. ROS is a by product from the Photosystem I/II handling of light energy. In...

  8. Study on the relationship of cytochrome C expression and cerebral edema in perihematomal brain tissue in patients with hypertensive cerebral hemorrhage

    Institute of Scientific and Technical Information of China (English)

    CAI Heng; LIU Guixiang; XU Chunsheng; LIU Qingxin; XU Xiaobo

    2007-01-01

    Objective To investigate the expression of cytochrome C in perihematomal brain tissue and its relationship with the histopathological change and formation of cerebral edema in patients with hypertensive cerebral hemorrhage. Methods Thirty four patients (23 male, 11 female) of hypertensive cerebral hemorrhage in hospital from Sep. 2001 to Sep. 2002 were selected with a mean age 55.6± 10.2 years (from 35 to 75 years). The mean volume of hemorrhagic blood was 50.4±11.6 ml (from 25 to 85 ml). The perihematomal brain tissue was obtained from the minimally invasive surgery. Histopathological change and expressions of cytochrome C in perihematomal brain tissue was detected by histopathological and immunohistochemical techniques. The volume of perihematomal cerebral edema was determined by computed tomographic scan before operation. The results of staining and the volume of perihematomal cerebral edema were analyzed with double blind fashion. Results Perihematomal cerebral edema were found 12-72h after cerebral hemorrhage. Myelin sheath degeneration, condensation of nucleus and typical apopototic body were observed in perihematomal brain tissue. Expression of cytochrome C in perihematomal brain tissue was observed at 4 h and reached peak around 48-72 h after cerebral hemorrhage. Cytochrome C expressed higher positively in 16 patients and lower positively in 13 patients. Cytochrome C expression was not detected only in 5 patints. There were significant differences in volume of perihematomal cerebral edema with different expression of cytochrome C in perihematomal brain tissue (P<0.01). Conclusions Cytochrome C expression was upregulated in perihematomal brain tissue in patients with hypertensive cerebral hemorrhage. Cytochrome C might involve in the histopathological change and the formation of perihematomal cerebral edema.

  9. Alveolar gas exchange, oxygen delivery and tissue deoxygenation in men and women during incremental exercise.

    Science.gov (United States)

    Peltonen, Juha E; Hägglund, Harriet; Koskela-Koivisto, Tiina; Koponen, Anne S; Aho, Jyrki M; Rissanen, Antti-Pekka E; Shoemaker, J Kevin; Tiitinen, Aila; Tikkanen, Heikki O

    2013-08-15

    We investigated whether leg and arm skeletal muscle, and cerebral deoxygenation, differ during incremental cycling exercise in men and women, and if women's lower capacity to deliver O2 affects tissue deoxygenation. Men (n=10) compared to women (n=10), had greater cardiac output, which with greater hemoglobin concentration produced greater absolute (QaO2) and body size-adjusted oxygen delivery (QaO2i) at peak exercise. Despite women's lower peak QaO2, their leg muscle deoxygenation was similar at a given work rate and QaO2, but less than in men at peak exercise (Δtissue saturation index -27.1 ± 13.2% vs. -11.8 ± 5.7%, Pexercise, oxygen uptake was associated both with QaO2 and leg muscle deoxygenation (both Pmuscle and cerebral deoxygenation did not differ between sexes at peak exercise. Thus, both high O2 delivery and severe active muscle deoxygenation are determinants of good exercise performance, and active muscle deoxygenation responses are regulated partly in a sex-specific manner with an influence of exercise capacity. PMID:23707876

  10. Long-term existence of cerebral hypoxic tissue in a rat model of cerebral ischemia/reperfusion injury

    Institute of Scientific and Technical Information of China (English)

    Yidong Wang; Jingrui Pan; Yu Qiu; Xiangpen Li; Mei Li; Ying Peng

    2009-01-01

    BACKGROUND: Hypoxic tissue surrounding the ischemic core may represent the ischemic penumbra following cerebral infarction. However, some studies have shown that the duration of ischemic tissue is longer than previously believed.OBJECTIVE: To clarify whether cerebral hypoxic tissue could survive long-term and whether it is altered in rats following cerebral infarction; to establish an ischemia/reperfusion model in which hypoxic tissue exists for extended periods of time.DESIGN, TIME AND SETTING: A completely randomized grouping and controlled experiment was performed at the Experimental Animal Center of Sun Yat-sen University and Medical Research Center, the Second Affiliated Hospital of Sun Yat-sen University between June and December 2008. MATERIALS: 4,9-diaza-3,3,10,10-tetramethyldodecan-2, 11-dione dioxime (BnAO) (HL91), used as the hypoxic marker for autoradiography, was supplied by the Beijing Syncor Star Medicinal, China, and the flesh eluent Na99TcmO4 to mark HL91 was supplied by Guangzhou Medical Isotope Center of the China Institute of Atomic Energy. 2-(2-nitro-1H-imidazole-1-yl)-N-(2,2,3,3,3-pentafluoropropyl) acetamide (EF5) and its antibody ELK3-51, used as a hypoxic marker for immunofluorescence, were supplied by the University of Pennsylvania, USA.METHODS: Male Sprague Dawley rats were randomly divided into four groups: 1.5-hour ischemia/reperfusion group (1.5 h IR), 2-hour ischemia/reperfusion group (2 h IR), 3-hour ischemia/reperfusion group (3 h IR), and permanent ischemia (PI) group, with 21 rats in each group. The middle cerebral artery occlusion model was established using the intraluminal suture method, while reperfusion was performed by removing the suture at each observation time point. However, in the PI group, the suture was left in the artery.MAIN OUTCOME MEASURES: Area and average absorbance of fluorescence, representing hypoxic tissue, were measured by image-analysis.RESULTS: Autoradiography revealed positive hypoxia at days 1 and 14

  11. Is cerebral oxygenation negatively affected by infusion of norepinephrine in healthy subjects?

    DEFF Research Database (Denmark)

    Brassard, P.; Seifert, T.; Secher, Niels H.

    2009-01-01

    BACKGROUND: Vasopressor agents are commonly used to increase mean arterial pressure (MAP) in order to secure a pressure gradient to perfuse vital organs. The influence of norepinephrine on cerebral oxygenation is not clear. The aim of this study was to evaluate the impact of the infusion of...... norepinephrine on cerebral oxygenation in healthy subjects. METHODS: Three doses of norepinephrine (0.05, 0.1, and 0.15 microg kg(-1) min(-1) for 20 min each) were infused in nine healthy subjects [six males; 26 (6) yr, mean (SD)]. MAP, cerebral oxygenation characterized by frontal lobe oxygenation (Sc(O2)) and...... infused at 0.1 microg kg(-1) min(-1) [Sc(O2): 78 (75-94) to 69 (61-83)%; P < 0.05; Sjv(O2): 67 (8) to 64 (7)%; P < 0.01]. MCA Vmean was reduced with each dose of norepinephrine [56.9 (11.2) to 55.0 (11.7) cm s(-1); P < 0.05] and Pa(CO2) lowered from 5.4 (0.4) to 5.1 (0.4) kPa (P < 0.001). CONCLUSIONS...

  12. Systematic review of near-infrared spectroscopy determined cerebral oxygenation during non-cardiac surgery

    Directory of Open Access Journals (Sweden)

    HenningBayNielsen

    2014-03-01

    Full Text Available Near-infrared spectroscopy (NIRS is used to monitor regional cerebral oxygenation (rScO2 during cardiac surgery but is less established during non-cardiac surgery. This systematic review aimed i to determine the non-cardiac surgical procedures that provoke a reduction in rScO2 and ii to evaluate whether an intraoperative reduction in rScO2 influences postoperative outcome. The PubMed and Embase database were searched from inception until April 30, 2013 and inclusion criteria were intraoperative NIRS determined rScO2 in adult patients undergoing non-cardiac surgery. The type of surgery and number of patients included were recorded. There was included 113 articles and evidence suggests that rScO2 is reduced during thoracic surgery involving single lung ventilation, major abdominal surgery, hip surgery, and laparascopic surgery with the patient placed in anti-Tredelenburg’s position. Shoulder arthroscopy in the beach chair and carotid endarterectomy with clamped internal carotid artery also cause pronounced cerebral desaturation. A >20% reduction in rScO2 coincides with indices of regional and global cerebral ischemia during carotid endarterectomy. Following thoracic surgery, major orthopedic and abdominal surgery the occurrence of postoperative cognitive dysfunction might be related to intraoperative cerebral desaturation. In conclusion, certain non-cardiac surgical procedures is associated with an increased risk for the occurrence of regional cerebral oxygenation. Evidence for an association between cerebral desaturation and postoperative outcome parameters other than cognitive dysfunction needs to be established.

  13. New Molecular Knowledge Towards the Trigemino-Cardiac Reflex as a Cerebral Oxygen-Conserving Reflex

    Directory of Open Access Journals (Sweden)

    N. Sandu

    2010-01-01

    Full Text Available The trigemino-cardiac reflex (TCR represents the most powerful of the autonomous reflexes and is a subphenomenon in the group of the so-called “oxygen-conserving reflexes”. Within seconds after the initiation of such a reflex, there is a powerful and differentiated activation of the sympathetic system with subsequent elevation in regional cerebral blood flow (CBF, with no changes in the cerebral metabolic rate of oxygen (CMRO2 or in the cerebral metabolic rate of glucose (CMRglc. Such an increase in regional CBF without a change of CMRO2 or CMRglc provides the brain with oxygen rapidly and efficiently. Features of the reflex have been discovered during skull base surgery, mediating reflex protection projects via currently undefined pathways from the rostral ventrolateral medulla oblongata to the upper brainstem and/or thalamus, which finally engage a small population of neurons in the cortex. This cortical center appears to be dedicated to transduce a neuronal signal reflexively into cerebral vasodilatation and synchronization of electrocortical activity; a fact that seems to be unique among autonomous reflexes. Sympathetic excitation is mediated by cortical-spinal projection to spinal preganglionic sympathetic neurons, whereas bradycardia is mediated via projections to cardiovagal motor medullary neurons. The integrated reflex response serves to redistribute blood from viscera to the brain in response to a challenge to cerebral metabolism, but seems also to initiate a preconditioning mechanism. Previous studies showed a great variability in the human TCR response, in special to external stimuli and individual factors. The TCR gives, therefore, not only new insights into novel therapeutic options for a range of disorders characterized by neuronal death, but also into the cortical and molecular organization of the brain.

  14. Impaired cerebral blood flow and oxygenation during exercise in type 2 diabetic patients

    DEFF Research Database (Denmark)

    Kim, Yu-Sok; Seifert, Thomas; Brassard, Patrice;

    2015-01-01

    Endothelial vascular function and capacity to increase cardiac output during exercise are impaired in patients with type 2 diabetes (T2DM). We tested the hypothesis that the increase in cerebral blood flow (CBF) during exercise is also blunted and, therefore, that cerebral oxygenation becomes.......05). In contrast, CBF increased ~20% during exercise in the control group while the brain uptake of lactate and glucose was similar in the two groups. In conclusion, these results suggest that impaired CBF and oxygenation responses to exercise in T2DM patients may relate to limited ability to increase cardiac...... affected and perceived exertion increased in T2DM patients. We quantified cerebrovascular besides systemic hemodynamic responses to incremental ergometer cycling exercise in eight male T2DM and seven control subjects. CBF was assessed from the Fick equation and by transcranial Doppler-determined middle...

  15. Lung vital capacity and oxygen saturation in adults with cerebral palsy

    Directory of Open Access Journals (Sweden)

    Lampe R

    2014-12-01

    Full Text Available Renée Lampe,1,2 Tobias Blumenstein,2 Varvara Turova,2 Ana Alves-Pinto2 1Markus Würth Stiftungsprofessur, Technical University of Munich, Munich, Germany; 2Research Unit for Cerebral Palsy and Children Neuroorthopaedics of the Buhl-Strohmaier Foundation, Orthopedic Department of the Clinic “rechts der Isar” of the Technical University of Munich, Munich, Germany Background: Individuals with infantile cerebral palsy have multiple disabilities. The most conspicuous syndrome being investigated from many aspects is motor movement disorder with a spastic gait pattern. The lung function of adults with spasticity attracts less attention in the literature. This is surprising because decreased thoracic mobility and longstanding scoliosis should have an impact on lung function. With increasing age and the level of disability, individuals become susceptible to lung infections and reflux illness, and these are accompanied by increased aspiration risk. This study examined, with different methods, to what extent adults with congenital cerebral palsy and acquired spastic paresis – following traumatic brain injury – showed restriction of lung function. It also assessed the contribution of disability level on this restriction.Methods: The oxygen saturation of 46 adults with a diagnosis of cerebral palsy was measured with an oximeter. Lung vital capacity was measured with a mobile spirometer and excursion of the thorax was clinically registered. The gross motor function levels and the presence or absence of scoliosis were determined.Results: A significantly positive correlation between lung vital capacity and chest expansion was established. Both the lung vital capacity and the thorax excursion decreased with increases in gross motor function level. Oxygen saturation remained within the normal range in all persons, in spite of reduced values of the measured lung parameters. No statistically significant dependency between lung vital capacity and oxygen

  16. Hyperbaric oxygen combined with drug therapy in the treatment of acute cerebral infarction clinical analysis

    Institute of Scientific and Technical Information of China (English)

    Wen-Cui Lin; Kang Lin; Jing Wang; Shuai Li

    2015-01-01

    Objective:To explore the effects of hyperbaric oxygen combined with edaravone, salviae miltiorrhizae and ligustrazine and sodium ozagrel in the treatment of acute cerebral infarction clinical analysis.Methods: A total of 200 cases of acute cerebral infraction patients were randomly divided into observation group and control group. The control group was treated with edaravone, salvia miltiorrhizae and ligustrazine and sodium ozagrel; on the basis of treatment in control group, the observation group was combined with hyperbaric oxygen therapy. The neurological deficit scores were observed before and after treatment in patients of two groups, meanwhile the activities of daily living (ADL) and clinical effects were compared.Results: The total effective rate in observation group (92%) was significantly higher than control group (79%), the differences were statistically significant; the score of ADL in observation group after treatment was obviously higher than control group [(79.91±5.16)vs (61.62±5.60)], and the differences were statistically significant. The neurological deficit scores after treatment were obviously lower than the control group [(9.55±4.13)vs (15.46±4.92)], the differences were statistically significant.Conclusion: Hyperbaric oxygen combined with edaravone, salvia miltiorrhizae and ligustrazine and sodium ozagrel in the treatment of acute cerebral infarction can improve the symptoms of microcirculation and neurologic impairment, and improve the patient s quality of life.

  17. Coupling of cerebral blood flow and oxygen metabolism is conserved for chromatic and luminance stimuli in human visual cortex

    OpenAIRE

    Leontiev, Oleg; Buracas, Giedrius T.; Liang, Christine; Ances, Beau M.; Perthen, Joanna E.; Shmuel, Amir; Buxton, Richard B.

    2012-01-01

    The ratio of the changes in cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO2) during brain activation is a critical determinant of the magnitude of the blood oxygenation level dependent (BOLD) response measured with functional magnetic resonance imaging (fMRI). Cytochrome oxidase (CO), a key component of oxidative metabolism in the mitochondria, is non-uniformly distributed in visual area V1 in distinct blob and interblob regions, suggesting significant spatial variation...

  18. A Decrease in Spatially Resolved Near-Infrared Spectroscopy-Determined Frontal Lobe Tissue Oxygenation by Phenylephrine Reflects Reduced Skin Blood Flow

    DEFF Research Database (Denmark)

    Ogoh, Shigehiko; Sato, Kohei; Okazaki, Kazunobu;

    2014-01-01

    BACKGROUND: Spatially resolved near-infrared spectroscopy-determined frontal lobe tissue oxygenation (ScO2) is reduced with administration of phenylephrine, while cerebral blood flow may remain unaffected. We hypothesized that extracranial vasoconstriction explains the effect of phenylephrine on Sc...

  19. Renal Tissue Oxygenation in Essential Hypertension and Chronic Kidney Disease

    Directory of Open Access Journals (Sweden)

    Menno Pruijm

    2013-01-01

    Full Text Available Animal studies suggest that renal tissue hypoxia plays an important role in the development of renal damage in hypertension and renal diseases, yet human data were scarce due to the lack of noninvasive methods. Over the last decade, blood oxygenation level-dependent magnetic resonance imaging (BOLD-MRI, detecting deoxyhemoglobin in hypoxic renal tissue, has become a powerful tool to assess kidney oxygenation noninvasively in humans. This paper provides an overview of BOLD-MRI studies performed in patients suffering from essential hypertension or chronic kidney disease (CKD. In line with animal studies, acute changes in cortical and medullary oxygenation have been observed after the administration of medication (furosemide, blockers of the renin-angiotensin system or alterations in sodium intake in these patient groups, underlining the important role of renal sodium handling in kidney oxygenation. In contrast, no BOLD-MRI studies have convincingly demonstrated that renal oxygenation is chronically reduced in essential hypertension or in CKD or chronically altered after long-term medication intake. More studies are required to clarify this discrepancy and to further unravel the role of renal oxygenation in the development and progression of essential hypertension and CKD in humans.

  20. Positron emission tomography in cerebrovascular disease: The relationship between regional cerebral blood flow, blood volume and oxygen metabolism

    International Nuclear Information System (INIS)

    Positron emission tomography in cerebrovascular disease has demonstrated the importance of the relationship between regional cerebral blood flow and the cerebral metabolic activity. In acute stroke it has been found that within the first hours after the onset of symptoms cerebral blood flow in the affected area is more depressed than cerebral oxygen utilisation. This relative preservation of oxygen utilisation results from an increase in the oxygen extraction ratio far above its normal value. However, the oxygen extraction fraction subsequently falls in the following days indicating the transition from a situation of possibly reversible ischaemia to irreversible infarction. In patients with carotid occlusive disease an increase in the oxygen extraction ratio has been observed only in very few cases. It has been shown, however, that at an earlier stage the relationship between CBF and CBV (as CBF/CBV-ratio) provides a sensitive measure of diminished perfusion pressure which could be helpful for the selection of patients for EC-IC bypass surgery. In patients with sickle cell anaemia it has been found that oxygen delivery to the brain is maintained by an increase in cerebral blood flow, whereas the oxygen extraction ratio is not increased despite the presence of a low oxygen affinity haemoglobin. Preliminary observations in classical migraine suggest an ischaemic situation during the attack. (orig.)

  1. Improvement in the Ultrastructures of Nervous Tissues Damaged in Cerebral Ischemic Rate by Picroside II

    Directory of Open Access Journals (Sweden)

    Li Zhao

    2015-01-01

    Full Text Available The aim of present study was to verify the neuroprotective effect of picroside II on cerebral ischemic injury in rats from the perspective of neuropathology. Healthy adult male Wistar rats were used to establish the forebrain ischemic model. Transmission Electron Microscopy (TEM was used to observe the ultrastructure of neurons, astrocytes, myelin and the Blood-Brain Barrier (BBB. There was morphological damage in neuron, astrocyte, myelin and BBB after cerebral ischemia. After treatment by picroside II, the degree of damage in neuron, astrocytes, myelin and BBB was reduced. These results suggest that picroside II could significantly improve the morphosis of nerve tissue after cerebral ischemia and play a neuroprotective effect on cerebral ischemic injury in rats.

  2. Measurement of local blood flow and oxygen consumption in evolving irreversible cerebral infarction: an in vivo study in man

    International Nuclear Information System (INIS)

    Positron emission tomography (PET) allows in vivo measurement of local cerebral blood flow (1CBF), oxygen consumption rate (1CMRO2) and glucose utilisation (1CMRG1c) in man. Although 1CMRG1c is accessible in animals, this is not the case for 1CMRO2, an excellent index of local functional state. PET imaging of the local interrelationship of CBF and metabolism in completed ischemic stroke has attracted considerable interest because of its potential to differentiate irreversibly damaged from viable tissue on the basis of the CBF- metabolism patterns. Several qualitative or semi-quantitative pioneering studies provided a limited insight into this question, while the single truly quantitative study was only briefly reported. We report here a detailed study of the local CBF-CMRO2 quantitative patterns in irreversibly infarcted brain regions

  3. Agreement of noninvasive cerebral oxygenation with mixed venous oxygen saturation in patients undergoing ECMO-therapy

    OpenAIRE

    H. Paarmann; J. Schön; W. Schmidt; Heinze, H; K.-U. Berger; B. Sedemund-Adib; Bechtel, M; Heringlake, M; H. V. Groesdonk

    2011-01-01

    Purpose: Approximately 1% of patients require temporary circulatory support due to cardiogenic shock following cardiac surgery. These patients are at risk of a mismatch between oxygen delivery and demand and carry a substantial mortality and morbidity risk. Mixed venous oxygen saturation (SvO2) is the still the “gold standard” for the determination of the ratio between systemic oxygen delivery and consumption (DO2/VO2 ratio) in cardiac surgery patients. A noninvasive technique is thought to b...

  4. Revascularization Using an Extracorporeal Pump for the Treatment of Cerebral Embolism in the Acute Stage: For Protection of the Brain Tissue from Irreversible Change due to Cerebral Embolism

    OpenAIRE

    Sonobe, M.; Nakai, Y.; Matsumaru, Y.; Sugita, K.

    2001-01-01

    Object. For patients with cerebral embolism, we are using an extracorporeal pump to revascularize the more peripheral brain tissues far from the thrombus, proceeding the microcatheter beyond the thrombus, and dissolving the thrombus during a satisfactory time as required.

  5. Challenges in understanding the impact of blood pressure management on cerebral oxygenation in the preterm brain

    Directory of Open Access Journals (Sweden)

    Aminath eAzhan

    2012-12-01

    Full Text Available Systemic hypotension in preterm infants has been related to increased mortality, cerebrovascular lesions and neurodevelopmental morbidity. Treatment of hypotension with inotropic medications aims at preservation of end organ perfusion and oxygen delivery, especially the brain. The common inotropic medications in preterm infants include dopamine, dobutamine, adrenalin, with adjunctive use of corticosteroids in cases of refractory hypotension. Whether maintenance of mean arterial blood pressure (MAP by use of inotropic medication is neuroprotective or not remains unclear. This review explores the different inotropic agents and their effects on perfusion and oxygenation in the preterm brain, in clinical studies as well as in animal models. Dopamine and adrenalin, because of their -adrenergic vasoconstrictor actions, have raised concerns of reduction in cerebral blood flow (CBF. Several studies in hypotensive preterm infants have shown that dopamine elevates CBF together with increased MAP, in keeping with limited cerebro-autoregulation. Adrenaline is also effective in raising cerebral perfusion together with MAP in preterm infants. Experimental studies in immature animals show no cerebro-vasoconstrictive effects of dopamine or adrenaline, but demonstrate the consistent findings of increased cerebral perfusion and oxygenation with the use of dopamine, dobutamine and adrenaline, alongside with raised MAP. Both clinical and animal studies report the transitory effects of adrenaline in increasing plasma lactate, and blood glucose, which might render its use as a 2nd line therapy. To investigate the cerebral effects of inotropic agents in long-term outcome in hypotensive preterm infants, carefully designed prospective research possibly including preterm infants with permissive hypotension is required. Preterm animal models would be useful in investigating the relationship between the physiological effects of inotropes and histopathology outcomes in

  6. Monitorization of the effects of spinal anaesthesia on cerebral oxygen saturation in elder patients using near-infrared spectroscopy

    Directory of Open Access Journals (Sweden)

    Aysegul Kusku

    2014-07-01

    Full Text Available OBJECTIVE: Central blockage provided by spinal anaesthesia enables realization of many surgical procedures, whereas hemodynamic and respiratory changes influence systemic oxygen delivery leading to the potential development of series of problems such as cerebral ischemia, myocardial infarction and acute renal failure. This study was intended to detect potentially adverse effects of hemodynamic and respiratory changes on systemic oxygen delivery using cerebral oxymetric methods in patients who underwent spinal anaesthesia. METHODS: Twenty-five ASA I-II Group patients aged 65-80 years scheduled for unilateral inguinal hernia repair under spinal anaesthesia were included in the study. Following standard monitorization baseline cerebral oxygen levels were measured using cerebral oximetric methods. Standardized Mini Mental Test (SMMT was applied before and after the operation so as to determine the level of cognitive functioning of the cases. Using a standard technique and equal amounts of a local anaesthetic drug (15 mg bupivacaine 5% intratechal blockade was performed. Mean blood pressure (MBP, maximum heart rate (MHR, peripheral oxygen saturation (SpO2 and cerebral oxygen levels (rSO2 were preoperatively monitored for 60 min. Pre- and postoperative haemoglobin levels were measured. The variations in data obtained and their correlations with the cerebral oxygen levels were investigated. RESULTS: Significant changes in pre- and postoperative measurements of haemoglobin levels and SMMT scores and intraoperative SpO2 levels were not observed. However, significant variations were observed in intraoperative MBP, MHR and rSO2 levels. Besides, a correlation between variations in rSO2, MBP and MHR was determined. CONCLUSION: Evaluation of the data obtained in the study demonstrated that post-spinal decline in blood pressure and also heart rate decreases systemic oxygen delivery and adversely effects cerebral oxygen levels. However, this downward change did

  7. Effects of hyperbaric oxygenation on hemodynamics and oxygen balance in tissues of miners with vibration pathologies

    Energy Technology Data Exchange (ETDEWEB)

    Larin, Eh.N.; Samokhatko, E.V.; Dorogan' , N.A. (Institut Gigieny Truda i Profzabolevanii, Krivoi Rog (Ukraine))

    1992-08-01

    Studies antihypoxic and microcirculation-stimulating effects of hyperbaric oxygenation in patients suffering from vibration pathologies. Combined clinical and laboratory examinations were conducted on a group of 56 miners diagnosed with the first stage of vibration disease. Ages of the patients varied from 40 to 49 years and duration of work at vibratory type tools was over 15 years. Hyperbaric oxygenation therapy was performed for 40-50 minutes every day in an OKA-MT single-seat compression chamber at a pressure of 1.5-1.7 atm. Hyperbaric therapy was accompanied by treatment with vitamins, biogenic stimulators, ganglioplegics and spasmolytics. Detailed observational data are given. The following conclusions are presented: hyperbaric oxygenation produces a positive effect on oxygen balance in tissues and regional bloodstreams and increases physical endurance; further research for elaborating therapeutic conditions of hyperbaric oxygenation for patients suffering from accompanying diseases is justified. 7 refs.

  8. Cerebral oxygenation monitoring during cardiac bypass surgery in infants with broad band spatially resolved spectroscopy

    Science.gov (United States)

    Soschinski, Jan; Ben Mine, Lofti; Geraskin, Dmitri; Bennink, Gerardus; Kohl-Bareis, Matthias

    2007-07-01

    Neurological impairments following cardio-pulmonary bypass (CPB) during open heart surgery can result from microembolism and ischaemia. Here we present results from monitoring cerebral haemodynamics during CPB with near infrared spatially resolved broadband spectroscopy. In particular, the study has the objective (a) to monitor oxy- and deoxy-hemoglobin concentrations (oxy-Hb, deoxy-Hb) and their changes as well as oxygen saturation during CPB surgery and (b) to develop and test algorithms for the calculation of these parameters from broad band spectroscopy. For this purpose a detection system was developed based on an especially designed lens imaging spectrograph with optimised sensitivity of recorded reflectance spectra for wavelengths between 600 and 1000 nm. The high f/#-number of 1:1.2 of the system results in about a factor of 10 higher light throughput combined with a lower astigmatism and crosstalk between channels when compared with a commercial mirror spectrometers (f/# = 1:4). For both hemispheres two independent channels each with three source-detector distances (ρ = 25 . 35 mm) were used resulting in six spectra. The broad band approach allows to investigate the influence of the wavelength range on the calculated haemoglobin concentrations and their changes and oxygen saturation when the attenuation A(λ) and its slope ΔA(λ)/Δρ are evaluated. Furthermore, the different depth sensitivities of these measurement parameters are estimated from Monte Carlo simulations and exploited for an optimization of the cerebral signals. It is demonstrated that the system does record cerebral oxygenation parameters during CPB in infants. In particular, the correlation of haemoglobin concentrations with blood supply (flow, pressure) by the heart-lung machine and the significant decreases in oxygen saturation during cardiac arrest is discussed.

  9. Cerebral lesions in patients with connective tissue diseases and systemic vasculitides: are there specific patterns?

    Science.gov (United States)

    Schedel, Joerg; Kuchenbuch, Sonja; Schoelmerich, Juergen; Feuerbach, Stefan; Geissler, Angela; Mueller-Ladner, Ulf

    2010-04-01

    This study was performed to evaluate whether specific patterns of cerebral lesions can be identified in different rheumatic disease entities. In 132 patients with different connective tissue diseases and vasculitides (systemic lupus erythematosus [SLE], systemic sclerosis [SSc], mixed connective tissue disease [MCTD], Wegener's granulomatosis [WG], immunocomplex vasculitides, antiphospholipid antibody syndrome [APS]), cerebral magnetic resonance imaging scans were performed. Patients were examined clinically, and laboratory parameters including autoantibodies were determined. Distinct distibution patterns could be identified; in WG, most lesions were seen in the cortex, the periventricular region, basal ganglia, and pons. In both SSc and MCTD, highest numbers of lesions could be detected in the corticomedullary junction. In APS, basal ganglia and periventricular white matter were involved predominantly. Generally, the maximum score of cerebral lesions correlated significantly with patients' age. Pathological values for antinuclear antibodies and increased levels of antiphospholipid antibodies were significantly correlated with the presence of cerebral lesions. WG patients and patients with other vasculitides most frequently showed neurological abnormalities. This study in patients with different rheumatic diseases showed distinct distribution patterns of cerebral lesions, which might help to differentiate between them. PMID:20398025

  10. Cerebral blood flow and oxygen metabolism in dementia with Lewy bodies

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Yoshitomo; Takahashi, Satoshi; Yonezawa, Hisashi [Iwate Medical Univ., Morioka (Japan). School of Medicine

    2000-06-01

    Regional cerebral blood flow (rCBF), oxygen metabolism (rCMRO{sub 2}) and the oxygen extraction fraction (rOEF) were measured using the steady-state {sup 15}O technique and positron emission tomography (PET) in six patients with dementia with Lewy bodies (DLB), and compared with ten patients with Alzheimer disease (AD) and six normal controls. In the AD patients, rCBF and rCMRO{sub 2} were significantly decreased in the frontal, parietal, and temporal cortices compared with controls. In DLB patients, rCBF and rCMRO{sub 2} were decreased in the frontal, parietal, temporal, and occipital cortices compared with controls, and were decreased more diffusely than in AD patients. rCBF and rCMRO{sub 2} were significantly decreased in occipital cortex compared with AD patients. rOEF was significantly increased in the parieto-temporal cortex in AD patients compared with controls. In DLB patients, rOEF was significantly increased not only in the parieto-temporal cortex but also in the occipital and frontal cortices compared with controls, and was significantly increased in the occipital cortex compared with AD patients. The diffuse reduction of cerebral blood flow and oxygen metabolism including the occipital cortex may be related to visual hallucination and other visuospatial deficits frequently seen in DLB patients. The increase in rOEF may be mainly due to the reduction in the vascular bed associated with decreased activity in the vasodilatory cholinergic system. (author)

  11. Cerebral blood flow and oxygen metabolism in dementia with Lewy bodies

    International Nuclear Information System (INIS)

    Regional cerebral blood flow (rCBF), oxygen metabolism (rCMRO2) and the oxygen extraction fraction (rOEF) were measured using the steady-state 15O technique and positron emission tomography (PET) in six patients with dementia with Lewy bodies (DLB), and compared with ten patients with Alzheimer disease (AD) and six normal controls. In the AD patients, rCBF and rCMRO2 were significantly decreased in the frontal, parietal, and temporal cortices compared with controls. In DLB patients, rCBF and rCMRO2 were decreased in the frontal, parietal, temporal, and occipital cortices compared with controls, and were decreased more diffusely than in AD patients. rCBF and rCMRO2 were significantly decreased in occipital cortex compared with AD patients. rOEF was significantly increased in the parieto-temporal cortex in AD patients compared with controls. In DLB patients, rOEF was significantly increased not only in the parieto-temporal cortex but also in the occipital and frontal cortices compared with controls, and was significantly increased in the occipital cortex compared with AD patients. The diffuse reduction of cerebral blood flow and oxygen metabolism including the occipital cortex may be related to visual hallucination and other visuospatial deficits frequently seen in DLB patients. The increase in rOEF may be mainly due to the reduction in the vascular bed associated with decreased activity in the vasodilatory cholinergic system. (author)

  12. Dehydration affects cerebral blood flow but not its metabolic rate for oxygen during maximal exercise in trained humans

    DEFF Research Database (Denmark)

    Trangmar, Steven J; Chiesa, Scott T; Stock, Christopher G;

    2014-01-01

    Intense exercise is associated with a reduction in cerebral blood flow (CBF), but regulation of CBF during strenuous exercise in the heat with dehydration is unclear. We assessed internal (ICA) and common carotid artery (CCA) haemodynamics (indicative of CBF and extra-cranial blood flow), middle...... cerebral artery velocity (MCA Vmean), arterial-venous differences and blood temperature in 10 trained males during incremental cycling to exhaustion in the heat (35°C) in control, dehydrated and rehydrated states. Dehydration reduced body mass (75.8 ± 3 vs. 78.2 ± 3 kg), increased internal temperature (38...... decline in cerebral perfusion with dehydration was accompanied by increased O2 extraction (P < 0.05), resulting in a maintained cerebral metabolic rate for oxygen (CMRO2). In all conditions, reductions in ICA and MCA Vmean were associated with declining cerebral vascular conductance, increasing jugular...

  13. Depressed cerebral oxygen metabolism in patients with chronic renal failure. A positron emission tomography study

    International Nuclear Information System (INIS)

    In order to elucidate brain oxygen metabolism in uremic patients, the regional cerebral blood flow (rCBF), oxygen extraction (rOEF) and oxygen metabolism (rCMRO2) were measured by positron emission tomography (PET) in both 10 hemodialysis patients (HD: male [m]/female [f]=2/8, age of 49±3 [SEM] years old, HD duration of 113±26 months) and 13 pre-dialysis renal failure patients (CRF: m/f=10/3, age of 61±2 years old, serum creatinine (SCr) of 6.3±1.0 mg/dl). Data were compared with 20 non-uremic subjects (Control: m/f=7/13, age of 62±2 years old, SCr of 0.9±0.1 mg/dl). They had no neurological abnormalities, congestive heart failure, history of cerebrovascular accident, diabetes mellitus, or symptomatic brain lesion on magnetic resonance imaging. The age of HD was significantly younger than the other groups (p2 in both HD (1.82±0.10 ml/min/100 g) and CRF (1.95±0.09) showed significantly lower values as compared to Control (2.23±0.05) (p<0.01, respectively). Hemispheric rCBF in HD (35.6±2.1 ml/100 g/min) and in CRF (36.1±2.1) were not different from that in Control (31.8±1.4). Hemispheric rOEF in CRF (45.7±1.6%) was significantly higher than that in Control (40.5±1.2%) (p<0.02), but that in HD (43.7±1.9%) did not increase significantly. These tendencies were similar in all regions of interest, especially in the cerebral cortices, but not in the cerebellum. All PET parameters in the frontal cortices tended to show the lowest value in renal failure patients. For all HD patients, rCBF in both the frontal cortex and the white matter correlated inversely with HD duration (frontal cortex: r=-0.649, p<0.05; white matter: r=-0.706, p<0.02). Based on these data, it is concluded that brain oxygen metabolism is depressed in renal failure patients on or before hemodialysis treatment. The cause for the depressed brain oxygen metabolism is considered to be due either to the dysregulation of cerebral circulation or to lower brain cell activity. (author)

  14. Cerebral energy metabolism during induced mitochondrial dysfunction

    DEFF Research Database (Denmark)

    Nielsen, T H; Bindslev, TT; Pedersen, S M;

    2013-01-01

    In patients with traumatic brain injury as well as stroke, impaired cerebral oxidative energy metabolism may be an important factor contributing to the ultimate degree of tissue damage. We hypothesize that mitochondrial dysfunction can be diagnosed bedside by comparing the simultaneous changes in...... brain tissue oxygen tension (PbtO(2)) and cerebral cytoplasmatic redox state. The study describes cerebral energy metabolism during mitochondrial dysfunction induced by sevoflurane in piglets....

  15. Effects of normobaric oxygen and melatonin on reperfusion injury: role of cerebral microcirculation.

    Science.gov (United States)

    Beker, Mustafa C; Caglayan, Ahmet B; Kelestemur, Taha; Caglayan, Berrak; Yalcin, Esra; Yulug, Burak; Kilic, Ulkan; Hermann, Dirk M; Kilic, Ertugrul

    2015-10-13

    In order to protect the brain before an irreversible injury occurs, penumbral oxygenation is the primary goal of current acute ischemic stroke treatment. However, hyperoxia treatment remains controversial due to the risk of free radical generation and vasoconstriction. Melatonin is a highly potent free radical scavenger that protects against ischemic stroke. Considering its anti-oxidant activity, we hypothesized that melatonin may augment the survival-promoting action of normobaric oxygen (NBO) and prevent brain infarction. Herein, we exposed mice to 30 or 90 min of intraluminal middle cerebral artery occlusion (MCAo) and evaluated the effects of NBO (70% or 100% over 90 min), administered either alone or in combination with melatonin (4 mg/kg, i.p.), on disseminate neuronal injury, neurological deficits, infarct volume, blood-brain barrier (BBB) permeability, cerebral blood flow (CBF) and cell signaling. Both NBO and particularly melatonin alone reduced neuronal injury, neurological deficits, infarct volume and BBB permeability, and increased post-ischemic CBF, evaluated by laser speckle imaging (LSI). They also improved CBF significantly in the ischemic- core and penumbra, which was associated with reduced IgG extravasation, DNA fragmentation, infarct volume, brain swelling and neurological scores. Levels of phosphorylated Akt, anti-apoptotic Bcl-xL, pro-apoptotic Bax and endothelial nitric oxide synthase (NOS) were re-regulated after combined oxygen and melatonin delivery, whereas neuronal and inducible NOS, which were increased by oxygen treatment, were not influenced by melatonin. Our present data suggest that melatonin and NBO are promising approaches for the treatment of acute-ischemic stroke, which encourage proof-of-concept studies in human stroke patients. PMID:26416428

  16. Effects of diving and oxygen on autonomic nervous system and cerebral blood flow.

    Science.gov (United States)

    Winklewski, Pawel J; Kot, Jacek; Frydrychowski, Andrzej F; Nuckowska, Magdalena K; Tkachenko, Yurii

    2013-09-01

    Recreational scuba diving is a popular leisure activity with the number of divers reaching several millions worldwide. Scuba diving represents a huge challenge for integrative physiology. In mammalian evolution, physiological reflexes developed to deal with lack of oxygen, rather than with an excess, which makes adaptations to scuba diving more difficult to describe and understand than those associated with breath-hold diving. The underwater environment significantly limits the use of equipment to register the organism's functions, so, in most instances, scientific theories are built on experiments that model real diving to some extent, like hyperbaric exposures, dive reflexes or water immersion. The aim of this review is to summarise the current knowledge related to the influence exerted by physiological conditions specific to diving on the autonomic nervous system and cerebral blood flow. The main factors regulating cerebral blood flow during scuba diving are discussed as follows: 1) increased oxygen partial pressure; 2) immersion-related trigemino-cardiac reflexes and 3) exposure to cold, exercise and stress. Also discussed are the potential mechanisms associated with immersion pulmonary oedema. PMID:24122190

  17. Cerebral oxygenation monitoring in patients with bilateral carotid stenosis undergoing urgent cardiac surgery: Observational case series

    Science.gov (United States)

    Aktuerk, Dincer; Mishra, Pankaj Kumar; Luckraz, Heyman; Garnham, Andrew; Khazi, Fayaz Mohammed

    2016-01-01

    Background: Patients with significant bilateral carotid artery stenosis requiring urgent cardiac surgery have an increased risk of stroke and death. The optimal management strategy remains inconclusive, and the available evidence does not support the superiority of one strategy over another. Materials and Methods: A number of noninvasive strategies have been developed for minimizing perioperative stroke including continuous real-time monitoring of cerebral oxygenation with near-infrared spectroscopy (NIRS). The number of patients presenting with this combination (bilateral significant carotid stenosis requiring urgent cardiac surgery) in any single institution will be small and hence there is a lack of large randomized studies. Results: This case series describes our early experience with NIRS in a select group of patients with significant bilateral carotid stenosis undergoing urgent cardiac surgery (n = 8). In contrast to other studies, this series is a single surgeon, single center study, where the entire surgery (both distal ends and proximal ends) was performed during single aortic clamp technique, which effectively removes several confounding variables. NIRS monitoring led to the early recognition of decreased cerebral oxygenation, and corrective steps (increased cardiopulmonary bypass flow, increased pCO2, etc.,) were taken. Conclusion: The study shows good clinical outcome with the use of NIRS. This is our “work in progress,” and we aim to conduct a larger study. PMID:26750675

  18. Cerebral oxygenation monitoring in patients with bilateral carotid stenosis undergoing urgent cardiac surgery: Observational case series

    Directory of Open Access Journals (Sweden)

    Dincer Aktuerk

    2016-01-01

    Full Text Available Background: Patients with significant bilateral carotid artery stenosis requiring urgent cardiac surgery have an increased risk of stroke and death. The optimal management strategy remains inconclusive, and the available evidence does not support the superiority of one strategy over another. Materials and Methods: A number of noninvasive strategies have been developed for minimizing perioperative stroke including continuous real-time monitoring of cerebral oxygenation with near-infrared spectroscopy (NIRS. The number of patients presenting with this combination (bilateral significant carotid stenosis requiring urgent cardiac surgery in any single institution will be small and hence there is a lack of large randomized studies. Results: This case series describes our early experience with NIRS in a select group of patients with significant bilateral carotid stenosis undergoing urgent cardiac surgery (n = 8. In contrast to other studies, this series is a single surgeon, single center study, where the entire surgery (both distal ends and proximal ends was performed during single aortic clamp technique, which effectively removes several confounding variables. NIRS monitoring led to the early recognition of decreased cerebral oxygenation, and corrective steps (increased cardiopulmonary bypass flow, increased pCO 2 , etc., were taken. Conclusion: The study shows good clinical outcome with the use of NIRS. This is our "work in progress," and we aim to conduct a larger study.

  19. Reduction in Cerebral Oxygenation After Prolonged Exercise in Hypoxia is Related to Changes in Blood Pressure.

    Science.gov (United States)

    Horiuchi, Masahiro; Dobashi, Shohei; Kiuchi, Masataka; Endo, Junko; Koyama, Katsuhiro; Subudhi, Andrew W

    2016-01-01

    We investigated the relation between blood pressure and cerebral oxygenation (COX) immediately after exercise in ten healthy males. Subjects completed an exercise and recovery protocol while breathing either 21% (normoxia) or 14.1% (hypoxia) O2 in a randomized order. Each exercise session included four sets of cycling (30 min/set, 15 min rest) at 50% of altitude-adjusted peak oxygen uptake, followed by 60 min of recovery. After exercise, mean arterial pressure (MAP; 87±1 vs. 84±1 mmHg, average values across the recovery period) and COX (68±1% vs. 58±1%) were lower in hypoxia compared to normoxia (Pblood pressure following exercise in hypoxia are (1) more pronounced than in normoxia, and (2) associated with reductions in COX. Together, these results suggest an impairment in cerebral autoregulation as COX followed changes in MAP more passively in hypoxia than in normoxia. These findings could help explain the increased risk for postexercise syncope at high altitude. PMID:26782200

  20. Hepatic encephalopathy is associated with decreased cerebral oxygen metabolism and blood flow, not increased ammonia uptake

    DEFF Research Database (Denmark)

    Dam, Gitte; Keiding, Susanne; Munk, Ole L;

    2013-01-01

    tomography (PET)/computed tomography (CT). Ten patients with cirrhosis were studied during an acute episode of HE; nine were reexamined after recovery. Nine patients with cirrhosis with no history of HE served as controls. Mean CMRO(2) increased from 0.73 µmol oxygen/mL brain tissue/min during HE to 0.......91 µmol oxygen/mL brain tissue/min after recovery (paired t test; P <0.05). Mean CBF increased from 0.28 mL blood/mL brain tissue/min during HE to 0.38 mL blood/mL brain tissue/min after recovery (P <0.05). After recovery from HE, CMRO(2) and CBF were not significantly different from values in the control...

  1. Effect of Short Periods of Normobaric Hyperoxia on Local Brain Tissue Oxygenation and Cerebrospinal Fluid Oxidative Stress Markers in Severe Traumatic Brain Injury

    OpenAIRE

    Puccio, Ava M.; Hoffman, Leslie A.; Bayir, Hülya; Zullo, Thomas G.; Fischer, Michael; Darby, Joseph; Alexander, Sheila; Dixon, C. Edward; Okonkwo, David O.; Kochanek, Patrick M.

    2009-01-01

    Preliminary evidence suggests local brain tissue oxygenation (PbtO2) values of ≤15 mm Hg following severe traumatic brain injury (TBI) represent brain tissue hypoxia. Accordingly, many neurotrauma units attempt to maintain PbtO2 ≥20 mm Hg to avoid hypoxia. This study tested the impact of a short (2 h) trial of normobaric hyperoxia on measures of oxidative stress. We hypothesized this treatment would positively affect cerebral oxygenation but negatively affect the cellular environment via oxid...

  2. Retrievable micro-inserts containing oxygen sensors for monitoring tissue oxygenation using EPR oximetry

    International Nuclear Information System (INIS)

    Tissue oxygenation is a crucial parameter in various physiopathological situations and can influence the therapeutic response of tumours. EPR oximetry is a reliable method for assessing and monitoring oxygen levels in vivo over long periods of time. Among the different paramagnetic oxygen sensors available for EPR oximetry, lithium phthalocyanine (LiPc) is a serious candidate for in vivo applications because of its narrow linewidth and its high signal-to-noise ratio. To enhance the biocompatibility of the sensors, fluoropolymer Teflon AF2400 was used to make cylindrical micro-inserts containing LiPc crystals. This new micro-pellet design has several advantages for in vivo studies, including the possibility of being able to choose the implant size, a high sensor content, the facility of in vivo insertion and complete protection with preservation of the oxygen sensor's characteristics. The response to oxygen and the kinetics of this response were tested using in vivo EPR: no differences were observed between micro-inserts and uncoated LiPc crystals. Pellets implanted in vivo in muscles conserved their responsiveness over a long period of time (∼two months), which is much longer than the few days of stability observed using LiPc crystals without protection by the implant. Finally, evaluation of the biocompatibility of the implants revealed no inflammatory reaction around the implantation area

  3. Algorithms for muscle oxygenation monitoring corrected for adipose tissue thickness

    Science.gov (United States)

    Geraskin, Dmitri; Platen, Petra; Franke, Julia; Kohl-Bareis, Matthias

    2007-07-01

    The measurement of skeletal muscle oxygenation by NIRS methods is obstructed by the subcutaneous adipose tissue which might vary between muscle haemoglobin / myoglobin concentrations. First, we demonstrate by comparison with ultrasound imaging that the optical lipid signal peaking at 930 nm is a good predictor of the adipose tissue thickness (ATT). Second, the algorithm is based on measurements of the wavelength dependence of the slope ΔA/Δρ of attenuation A with respect to source detector distance ρ and Monte Carlo simulations which estimate the muscle absorption coefficient based on this slope and the additional information of the ATT. Third, we illustrate the influence of the wavelength dependent transport scattering coefficient of the new algorithm by using the solution of the diffusion equation for a two-layered turbid medium. This method is tested on experimental data measured on the vastus lateralis muscle of volunteers during an incremental cycling exercise under normal and hypoxic conditions (corresponding to 0, 2000 and 4000 m altitude). The experimental setup uses broad band detection between 700 and 1000 nm at six source-detector distances. We demonstrate that the description of the experimental data as judged by the residual spectrum is significantly improved and the calculated changes in oxygen saturation are markedly different when the ATT correction is included.

  4. Preoperative regional cerebral oxygen saturation is a predictor of postoperative delirium in on-pump cardiac surgery patients: a prospective observational trial

    OpenAIRE

    Schoen, Julika; Meyerrose, Joscha; Paarmann, Hauke; Heringlake, Matthias; Hueppe, Michael; Berger, Klaus-Ulrich

    2011-01-01

    Introduction Postoperative delirium is an important problem in patients undergoing major surgery. Cerebral oximetry is a non-invasive method to detect imbalances in the cerebral oxygen supply/demand-ratio. Low preoperative cerebral oxygen saturation (ScO2) levels have been associated with postoperative delirium in non-cardiac surgery patients. The present prospective observational study determines the relationship between pre- and intra-operative ScO2 levels and postoperative delirium in pati...

  5. Effects of pH management during deep hypothermic bypass on cerebral oxygenation:alpha-stat versus pH-stat

    Institute of Scientific and Technical Information of China (English)

    郦志军; 尹小妹; 叶箭

    2004-01-01

    Objective: There is a remarkable lack of scientific evidence to support the option to use alpha-stat or pH-stat management, as to which is more beneficial to brain protection during deep hypothermic CPB. This study examined cortical blood flow (CBF), cerebral oxygenation, and brain oxygen consumption in relation to deep hypothermic CPB with alpha-stat or pH-stat management. Methods: Twenty-two pigs were cooled with alpha-stat or pH-stat during CPB to 15℃ esophageal temperature. CBF and cerebral oxygenation were measured continuously with a laser flowmeter and near-infrared spectroscopy, respectively. Brain oxygen consumption was measured with standard laboratory techniques. Results: During CPB cooling, CBF was significantly decreased, about 52.2%±6.3% (P<0.01 vs 92.6%±6.5% of pH-stat) at 15℃ in alpha-stat,whereas there were no significant changes in CBF in pH-stat. While cooling down, brain oxygen extraction (OER) progressively decreased, about 9.5%±0.9% and 10.9%±1.5% at 15 ℃ in alpha-stat and pH-stat, respectively. At 31℃ the decreased value in pH-stat was lower than in alpha-stat (29.9%±2.7% vs 22.5%±1.9%; P<0.05). The ratio of CBF/OER were 2.0±0.3 in alpha-stat and pH-stat, respectively; it was kept in constant level in alpha-stat, and significantly increased by 19℃ to 15℃ in pH-stat (4.9±0.9 vs 2.3±0.4; P<0.01). In mild hypothermia, cerebral oxyhemoglobin and oxygen saturation in alpha-stat were greater than that in pH-stat (102.5%±1.4% vs 99.1%±0.7%; P<0.05). In deep hypothermia, brain oxygen saturation in pH-stat was greater than that in alpha-stat (99.2%±1.0% vs 93.8%±1.0%; P<0.01), and deoxyhemoglobin in pH-stat decreased more greatly than that in alpha-stat (28.7%±6.8% vs 54.1%±4.7%; P<0.05). Conclusions: In mild hypothermic CPB, brain tissue oxygen saturation was greater in alpha-stat than in pH-stat. However, cerebral oxygenation and brain tissue oxygen saturation were better in pH-stat than in alpha-stat during

  6. Regional changes in cerebral blood flow oxygenation can indicate global changes in cerebral blood flow during coronary artery occlusion in juvenile pigs

    International Nuclear Information System (INIS)

    Near infrared spectroscopy (NIRS) is a widely employed method for assessment of regional cerebral oxygenation (RcStO2). RcStO2 values are expected to vary with changes in the relative amount of oxyhaemoglobin. The present experimental study aimed to assess the response of RcStO2 to controlled alterations of carotid blood flow (CQ). Landrace pigs were anesthetized followed by surgical preparation. Cyclic variations in cardiac output were accomplished by intermittently occluding the main stem of the left coronary artery. A flow measurement probe for assessing CQ was placed around the left carotid artery. One NIRS probe was placed on the left ipsilateral forehead to assess regional cerebral oximetry. Simultaneous registration of CQ and RcStO2 was conducted. There was a strong correlation for variation in CQ and RcStO2 signal values. Based on coherence analysis the fraction of power of the RcStO2 that was coherent with the CQ signal reached 0.84 ± 0.12 (P < 0.05) for frequencies lower than 0.1 Hz. The agreement of the sample-to-sample co-variation, as assessed by the Pearson correlation coefficient, was 0.83 ± 0.08 (P < 0.05). One explanatory component for variations in cerebral oxygenation verified by NIRS should be attributed to variations in the cerebral blood flow. (paper)

  7. Regional cerebral blood flow and oxygen consumption during normal human sleep

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Ken (Toho Univ., Tokyo (Japan). School of Medicine)

    1989-09-01

    Regional cerebral blood flow (rCBF), regional oxygen extraction fraction (rCEF) and regional cerebral metabolic rate for oxygen (rCMRO{sub 2}) were measured using the continuous inhalation technique for {sup 15}O with positron emission tomography (PET) during both wakefulness and sleep. Ten paid volunteers, with a mean age of 21.6 yrs., were deprived of sleep for a period of approximately 20 hours, and the experiments were performed mostly in the morning. {sup 15}O activity of both whole blood and the plasma, pixel count of PET, total arterial blood oxygen content were used for analysis of rCBF, rOEF and rCMRO{sub 2}. PET scannings were carried out mostly during the very light non-rapid eye movement (NREM) sleep, i.e. stage 1 and/or 2, and wakefulness. About 10 minutes after the start of continuous inhalation of {sup 15}O gas, the {sup 15}O activity of the brain was found to be in a steady-state condition. During this steady-state condition, PET scannings were performed for about 10 minutes. Regions of interest, square in shape and having an area of 2.8 cm{sup 3}, were set in each cortex on PET images of a horizontal cross-section of the brain, set at 45 mm above the orbitomeatal line. The rCBF and rCMRO{sub 2} were analysed in 5 of 10 male subjects during both wakefulness and NREM sleep, and only 3 were done during three sleep stages, including REM sleep. Levels of rCBF and rCMRO{sub 2} were found to be decreased in NREM sleep, and the decreasing rates were calculated at 10.2% and 7.6% from the level of wakefulness, respectively. There was no significant difference in the mean value of rOEF between wakefulness and NREM sleep. There were no significant regional differences found in the rate of decrease among the frontal, temporal and occipital cortices. It was considered that the decrease of rCBF and rCMRO{sub 2} during NREM sleep suggested a decrease of the activity levels in the cerebral functions. (author).

  8. Regional cerebral blood flow and oxygen consumption during normal human sleep

    International Nuclear Information System (INIS)

    Regional cerebral blood flow (rCBF), regional oxygen extraction fraction (rCEF) and regional cerebral metabolic rate for oxygen (rCMRO2) were measured using the continuous inhalation technique for 15O with positron emission tomography (PET) during both wakefulness and sleep. Ten paid volunteers, with a mean age of 21.6 yrs., were deprived of sleep for a period of approximately 20 hours, and the experiments were performed mostly in the morning. 15O activity of both whole blood and the plasma, pixel count of PET, total arterial blood oxygen content were used for analysis of rCBF, rOEF and rCMRO2. PET scannings were carried out mostly during the very light non-rapid eye movement (NREM) sleep, i.e. stage 1 and/or 2, and wakefulness. About 10 minutes after the start of continuous inhalation of 15O gas, the 15O activity of the brain was found to be in a steady-state condition. During this steady-state condition, PET scannings were performed for about 10 minutes. Regions of interest, square in shape and having an area of 2.8 cm3, were set in each cortex on PET images of a horizontal cross-section of the brain, set at 45 mm above the orbitomeatal line. The rCBF and rCMRO2 were analysed in 5 of 10 male subjects during both wakefulness and NREM sleep, and only 3 were done during three sleep stages, including REM sleep. Levels of rCBF and rCMRO2 were found to be decreased in NREM sleep, and the decreasing rates were calculated at 10.2% and 7.6% from the level of wakefulness, respectively. There was no significant difference in the mean value of rOEF between wakefulness and NREM sleep. There were no significant regional differences found in the rate of decrease among the frontal, temporal and occipital cortices. It was considered that the decrease of rCBF and rCMRO2 during NREM sleep suggested a decrease of the activity levels in the cerebral functions. (author)

  9. The relationship between cerebral oxygen saturation changes and post operative neurologic complications in patients undergoing cardiac surgery

    International Nuclear Information System (INIS)

    To study the relationship between cerebral oxygen saturation changes and postoperative neurologic complications. Seventy two adult patients with ASA class II, III who were scheduled for elective cardiac surgery, were randomized into three groups: Group I: with CPB (on -pump) Group II: without CPB (off- pump) Group III: valve surgery. Neuropsychological outcome was assessed by the Mini-Mental State Examination (MMSE). Cerebral oxygen saturation was also measured. There was no statistical difference in desaturation of more than 20% among three groups (P=0.113) but it was significant between group I and II (P=0.042). Changes of rSo/sub 2/ in different hours of surgery was significant in group I and group II (P=0.0001 in both) but it was not significant in group III ( P=0.075) . Although cerebral oximetry is a noninvasive and useful method of monitoring during cardiac surgery, it has low accuracy to determine postoperative neurologic complications. (author)

  10. Cerebral misery perfusion diagnosed using hypercapnic blood-oxygenation-level-dependent contrast functional magnetic resonance imaging: a case report

    Directory of Open Access Journals (Sweden)

    D'Souza Olympio

    2010-02-01

    Full Text Available Abstract Introduction Cerebral misery perfusion represents a failure of cerebral autoregulation. It is an important differential diagnosis in post-stroke patients presenting with collapses in the presence of haemodynamically significant cerebrovascular stenosis. This is particularly the case when cortical or internal watershed infarcts are present. When this condition occurs, further investigation should be done immediately. Case presentation A 50-year-old Caucasian man presented with a stroke secondary to complete occlusion of his left internal carotid artery. He went on to suffer recurrent seizures. Neuroimaging demonstrated numerous new watershed-territory cerebral infarcts. No source of arterial thromboembolism was demonstrable. Hypercapnic blood-oxygenation-level-dependent-contrast functional magnetic resonance imaging was used to measure his cerebrovascular reserve capacity. The findings were suggestive of cerebral misery perfusion. Conclusions Blood-oxygenation-level-dependent-contrast functional magnetic resonance imaging allows the inference of cerebral misery perfusion. This procedure is cheaper and more readily available than positron emission tomography imaging, which is the current gold standard diagnostic test. The most evaluated treatment for cerebral misery perfusion is extracranial-intracranial bypass. Although previous trials of this have been unfavourable, the results of new studies involving extracranial-intracranial bypass in high-risk patients identified during cerebral perfusion imaging are awaited. Cerebral misery perfusion is an important and under-recognized condition in which emerging imaging and treatment modalities present the possibility of practical and evidence-based management in the near future. Physicians should thus be aware of this disorder and of recent developments in diagnostic tests that allow its detection.

  11. Hyperbaric oxygen therapy for cerebral blood flow and electroencephalogram in patients with acute cerebral infarction Choice for therapeutic occasion

    Institute of Scientific and Technical Information of China (English)

    Lei Chen; Fei Li; Dexiang Gu

    2007-01-01

    BACKGROUND: Hyperbaric oxygen (HBO) therapy increases blood oxygen content, changes cerebral blood flow (CBF) and cerebral metabolism. Its therapeutic effects on cerebrovascular disease have been fully confirmed, but the occasion for HBO therapy is still unclear.OBJECTIVE: To observe the therapeutic effects of HBO therapy at different time on CBF and electroencephalogram (EEG) in patients with acute cerebral infarction (CI).DESIGN: Randomized controlled trial.SETTING: Department of Neurology, Shidong Hospital, Yangpu District of Shanghai.PARTICIPANTS: Ninety-six inpatients with acute CI, admitted to Department of Neurology, Shidong Hospital, Yangpu District of Shanghai from January 2001 to December 2006, were involved in this experiment. The involved participants met the diagnosis criteria of acute CI and confirmed by skull CT or MRI. They all were patients with moderate CI (16- 30 points) according to neurologic deficit score formulated by Chinese Medical Association. Informed consents of detected items and therapeutic regimen were obtained from all the involved participants. They were randomized into two groups with 48 in each:early-stage treatment group and advanced-stage treatment group. Among the 48 patients in the early-stage treatment group, 21 male and 27 female, aged 53 -68 years, 22 patients were found with basal ganglia infarction, 10 with brain lobe infarction, 16 with multiple infarction, 27 accompanied with hypertension and 2 accompanied with diabetes mellitus. Among the 48 patients in the advanced-stage treatment group, 23 male and 25 female, aged 52 - 71 years, 25 patients were found with basal ganglia infarction, 10 with brain lobe infarction, 12 with multiple infarction, 1 with brain stem infarction, 28 accompanied with hypertension and 1 accompanied with diabetes mellitus.METHODS: After admission, patients of two groups received routine drug treatment. ① Patients in the early-stage treatment group and advanced-stage treatment group began to

  12. Near-infrared spectroscopy assessed cerebral oxygenation during open abdominal aortic aneurysm repair

    DEFF Research Database (Denmark)

    Sørensen, Henrik; Nielsen, H B; Secher, N H

    2016-01-01

    not prevent an increase in ScO2 by 2 % (-1 to 4; P < 0.001) as EtCO2 increased 0.5 kPa (0.1-1.0; P < 0.001) despite an increase in ventilation by 1.8 l min(-1) (0.9-2.7; P < 0.001). Changes in ScO2 related to those in EtCO2 (r = 0.41; P = 0.0001) and cerebral deoxygenation (-15 %) was noted in three......During open abdominal aortic aneurism (AAA) repair cerebral blood flow is challenged. Clamping of the aorta may lead to unintended hyperventilation as metabolism is reduced by perfusion of a smaller part of the body and reperfusion of the aorta releases vasodilatory substances including CO2. We...... intend to adjust ventilation according end-tidal CO2 tension (EtCO2) and here evaluated to what extent that strategy maintains frontal lobe oxygenation (ScO2) as determined by near infrared spectroscopy. For 44 patients [5 women, aged 70 (48-83) years] ScO2, mean arterial pressure (MAP), EtCO2, and...

  13. Effects of rapid versus slow infusion of sodium bicarbonate on cerebral hemodynamics and oxygenation in preterm infants.

    NARCIS (Netherlands)

    Velden, A.A.E.M. van der; Hopman, J.C.W.; Klaessens, J.H.G.M.; Feuth, A.B.; Sengers, R.C.A.; Liem, K.D.

    2006-01-01

    BACKGROUND: Sodium bicarbonate (NaHCO3) is often used for correction of metabolic acidosis in preterm infants. The effects of NaHCO3 administration on cerebral hemodynamics and oxygenation are not well known. Furthermore, there is no consensus on infusion rate of NaHCO3. OBJECTIVES: To evaluate the

  14. Postoperative cognitive deficit after cardiopulmonary bypass with preserved cerebral oxygenation: a prospective observational pilot study

    Directory of Open Access Journals (Sweden)

    Meybohm Patrick

    2011-03-01

    Full Text Available Abstract Background Neurologic deficits after cardiac surgery are common complications. Aim of this prospective observational pilot study was to investigate the incidence of postoperative cognitive deficit (POCD after cardiac surgery, provided that relevant decrease of cerebral oxygen saturation (cSO2 is avoided during cardiopulmonary bypass. Methods cSO2 was measured by near infrared spectroscopy in 35 patients during cardiopulmonary bypass. cSO2 was kept above 80% of baseline and above 55% during anesthesia including cardiopulmonary bypass. POCD was tested by trail making test, digit symbol substitution test, Ray's auditorial verbal learning test, digit span test and verbal fluency test the day before and 5 days after surgery. POCD was defined as a decline in test performance that exceeded - 20% from baseline in two tests or more. Correlation of POCD with lowest cSO2 and cSO2 - threshold were determined explorative. Results POCD was observed in 43% of patients. Lowest cSO2 during cardiopulmonary bypass was significantly correlated with POCD (p = 0.015, r2 = 0.44, without Bonferroni correction. A threshold of 65% for cSO2 was able to predict POCD with a sensitivity of 86.7% and a specificity of 65.0% (p = 0.03, without Bonferroni correction. Conclusions Despite a relevant decrease of cerebral oxygen saturation was avoided in our pilot study during cardiopulmonary bypass, incidence of POCD was comparable to that reported in patients without monitoring. A higher threshold for cSO2 may be needed to reduce the incidence of POCD.

  15. Depressed cerebral oxygen metabolism in patients with chronic renal failure. A positron emission tomography study

    Energy Technology Data Exchange (ETDEWEB)

    Hirakata, Hideki; Kanai, Hidetoshi; Nakane, Hiroshi; Fujii, Ken-ichiro; Hirakata, Eriko; Ibayashi, Setsuro; Kuwabara, Yasuo; Deenitchna, S.S.; Fujishima, Masatoshi [Kyushu Univ., Fukuoka (Japan). Graduate School of Medical Sciences

    2001-07-01

    In order to elucidate brain oxygen metabolism in uremic patients, the regional cerebral blood flow (rCBF), oxygen extraction (rOEF) and oxygen metabolism (rCMRO{sub 2}) were measured by positron emission tomography (PET) in both 10 hemodialysis patients (HD: male [m]/female [f]=2/8, age of 49{+-}3 [SEM] years old, HD duration of 113{+-}26 months) and 13 pre-dialysis renal failure patients (CRF: m/f=10/3, age of 61{+-}2 years old, serum creatinine (SCr) of 6.3{+-}1.0 mg/dl). Data were compared with 20 non-uremic subjects (Control: m/f=7/13, age of 62{+-}2 years old, SCr of 0.9{+-}0.1 mg/dl). They had no neurological abnormalities, congestive heart failure, history of cerebrovascular accident, diabetes mellitus, or symptomatic brain lesion on magnetic resonance imaging. The age of HD was significantly younger than the other groups (p<0.02) and the hemoglobin (Hb) levels in both HD (10.5{+-}0.5 g/dl) and CRF (9.8{+-}0.9) were significantly lower than that in Control (13.3{+-}0.3) (p<0.02). In the hemisphere, rCMRO{sub 2} in both HD (1.82{+-}0.10 ml/min/100 g) and CRF (1.95{+-}0.09) showed significantly lower values as compared to Control (2.23{+-}0.05) (p<0.01, respectively). Hemispheric rCBF in HD (35.6{+-}2.1 ml/100 g/min) and in CRF (36.1{+-}2.1) were not different from that in Control (31.8{+-}1.4). Hemispheric rOEF in CRF (45.7{+-}1.6%) was significantly higher than that in Control (40.5{+-}1.2%) (p<0.02), but that in HD (43.7{+-}1.9%) did not increase significantly. These tendencies were similar in all regions of interest, especially in the cerebral cortices, but not in the cerebellum. All PET parameters in the frontal cortices tended to show the lowest value in renal failure patients. For all HD patients, rCBF in both the frontal cortex and the white matter correlated inversely with HD duration (frontal cortex: r=-0.649, p<0.05; white matter: r=-0.706, p<0.02). Based on these data, it is concluded that brain oxygen metabolism is depressed in renal failure

  16. Development of an ultrasound sensitive oxygen carrier for oxygen delivery to hypoxic tissue.

    Science.gov (United States)

    Eisenbrey, John R; Albala, Lorenzo; Kramer, Michael R; Daroshefski, Nick; Brown, David; Liu, Ji-Bin; Stanczak, Maria; O'Kane, Patrick; Forsberg, Flemming; Wheatley, Margaret A

    2015-01-15

    Radiation therapy is frequently used in the treatment of malignancies, but tumors are often more resistant than the surrounding normal tissue to radiation effects, because the tumor microenvironment is hypoxic. This manuscript details the fabrication and characterization of an ultrasound-sensitive, injectable oxygen microbubble platform (SE61O2) for overcoming tumor hypoxia. SE61O2 was fabricated by first sonicating a mixture of Span 60 and water-soluble vitamin E purged with perfluorocarbon gas. SE61O2 microbubbles were separated from the foam by flotation, then freeze dried under vacuum to remove all perfluorocarbon, and reconstituted with oxygen. Visually, SE61O2 microbubbles were smooth, spherical, with an average diameter of 3.1 μm and were reconstituted to a concentration of 6.5 E7 microbubbles/ml. Oxygen-filled SE61O2 provides 16.9 ± 1.0 dB of enhancement at a dose of 880 μl/l (5.7 E7 microbubbles/l) with a half-life under insonation of approximately 15 min. In in vitro release experiments, 2 ml of SE61O2 (1.3 E8 microbubbles) triggered with ultrasound was found to elevate oxygen partial pressures of 100ml of degassed saline 13.8 mmHg more than untriggered bubbles and 20.6 mmHg more than ultrasound triggered nitrogen-filled bubbles. In preliminary in vivo delivery experiments, triggered SE61O2 resulted in a 30.4 mmHg and 27.4 mmHg increase in oxygen partial pressures in two breast tumor mouse xenografts. PMID:25448552

  17. Brain tissue partial pressure of oxygen predicts the outcome of severe traumatic brain injury under mild hypothermia treatment

    Directory of Open Access Journals (Sweden)

    Sun H

    2016-08-01

    Full Text Available Hongtao Sun,1,* Maohua Zheng,2,* Yanmin Wang,1 Yunfeng Diao,1 Wanyong Zhao,1 Zhengjun Wei1 1Sixth Department of Neurosurgery, Affiliated Hospital of Logistics University of People’s Armed Police Force, Tianjin, 2Department of Neurosurgery, The First Hospital of Lanzhou University, Lanzhou, People’s Republic of China *These authors contributed equally to this work Objective: The aim of this study was to investigate the clinical significance and changes of brain tissue partial pressure of oxygen (PbtO2 in the course of mild hypothermia treatment (MHT for treating severe traumatic brain injury (sTBI. Methods: There were 68 cases with sTBI undergoing MHT. PbtO2, intracranial pressure (ICP, jugular venous oxygen saturation (SjvO2, and cerebral perfusion pressure (CPP were continuously monitored, and clinical outcomes were evaluated using the Glasgow Outcome Scale score. Results: Of 68 patients with sTBI, PbtO2, SjvO2, and CPP were obviously increased, but decreased ICP level was observed throughout the MHT. PbtO2 and ICP were negatively linearly correlated, while there was a positive linear correlation between PbtO2 and SjvO2. Monitoring CPP and SjvO2 was performed under normal circumstances, and a large proportion of patients were detected with low PbtO2. Decreased PbtO2 was also found after MHT. Conclusion: Continuous PbtO2 monitoring could be introduced to evaluate the condition of regional cerebral oxygen metabolism, thereby guiding the clinical treatment and predicting the outcome. Keywords: severe traumatic brain injury, hypothermia, brain tissue partial pressure of oxygen, therapy

  18. Combination therapy of normobaric oxygen with hypothermia or ethanol modulates pyruvate dehydrogenase complex in thromboembolic cerebral ischemia.

    Science.gov (United States)

    Cai, Lipeng; Thibodeau, Alexa; Peng, Changya; Ji, Xunming; Rastogi, Radhika; Xin, Ruiqiang; Singh, Sunpreet; Geng, Xiaokun; Rafols, Jose A; Ding, Yuchuan

    2016-08-01

    Pyruvate dehydrogenase complex (PDH) is a brain mitochondrial matrix enzyme. PDH impairment after stroke is particularly devastating given PDH's critical role in the link between anaerobic and aerobic metabolism. This study evaluates the restoration of oxidative metabolism and energy regulation with a therapeutic combination of normobaric oxygen (NBO) plus either therapeutic hypothermia (TH) or ethanol. Sprague-Dawley rats were subjected to middle cerebral artery occlusion with an autologous embolus. One hour after occlusion, tissue-type plasminogen activator (t-PA) was administered alone or with NBO (60%), EtOH (1.0 g/kg), or TH (33°C), either singly or in combination. Neurological deficit score and infarct volume were assessed 24 hr after t-PA-induced reperfusion. PDH activity and reactive oxygen species (ROS) levels were measured 3 and 24 hr after t-PA. Western blotting was used to detect PDH and pyruvate dehydrogenase kinase (PDK) protein expression. After t-PA in ischemic rats, NBO combined with TH or EtOH most effectively decreased infarct volume and neurological deficit. The combined therapies produced greater increases in PDH activity and protein expression as well as greater decreases in PDK expression. Compared with the monotherapeutic approaches, the combined therapies provided the most significant declines in ROS generation. Reperfusion with t-PA followed by 60% NBO improves the efficacy of EtOH or TH in neuroprotection by ameliorating oxidative injury and improving PDH regulation. Comparable neuroprotective effects were found when treating with either EtOH or TH, suggesting a similar mechanism of neuroprotection and the possibility of substituting EtOH for TH in clinical settings. © 2016 Wiley Periodicals, Inc. PMID:27027410

  19. Correlation of cutaneous tension distribution and tissue oxygenation with acute external tissue expansion

    Directory of Open Access Journals (Sweden)

    Marquardt C

    2009-11-01

    Full Text Available Abstract Today, the biomechanical fundamentals of skin expansion are based on viscoelastic models of the skin. Although many studies have been conducted in vitro, analyses performed in vivo are rare. Here, we present in vivo measurements of the expansion at the skin surface as well as measurement of the corresponding intracutaneous oxygen partial pressure. In our study the average skin stretching was 24%, with a standard deviation of 11%, excluding age or gender dependency. The measurement of intracutaneous oxygen partial pressure produced strong inter-individual fluctuations, including initial values at the beginning of the measurement, as well as varying individual patient reactions to expansion of the skin. Taken together, we propose that even large defect wounds can be closed successfully using the mass displacement caused by expansion especially in areas where soft, voluminous tissue layers are present.

  20. Spontaneous calcium waves in Bergman glia increase with age and hypoxia and may reduce tissue oxygen

    OpenAIRE

    Mathiesen, Claus; Brazhe, Alexey; Thomsen, Kirsten; Lauritzen, Martin

    2012-01-01

    Glial calcium (Ca2+) waves constitute a means to spread signals between glial cells and to neighboring neurons and blood vessels. These waves occur spontaneously in Bergmann glia (BG) of the mouse cerebellar cortex in vivo. Here, we tested three hypotheses: (1) aging and reduced blood oxygen saturation alters wave activity; (2) glial Ca2+ waves change cerebral oxygen metabolism; and (3) neuronal and glial wave activity is correlated. We used two-photon microscopy in the cerebellar cortexes of...

  1. Local cerebral blood flow (1CBF) and oxygen consumption (1CMRO2) in evolving irreversible ischemic infarction: a study with positron tomography and oxygen-15

    International Nuclear Information System (INIS)

    In 25 patients suffering from cerebral ischemia set up in the area of the internal carotid artery the local cerebral blood flow (lCBF) and local cerebral oxygen consumption (lCMRO2) were measured by the method of continuous inhalation of oxygen 15-labelled gas combined with positron emission tomography. These two local parameters and their ratio, the local oxygen extraction rate (lO2E), were studied inside the brain region tending spontaneously towards ischemic necrosis, a zone defined by means of repeated tomodensitometric examinations. The essential facts observed are the variability of the lCBF and the lO2E values, from extremely low to extremely high, whereas the collapse of the lCMRO2 is constant. Consequently this last parameter alone would be a good prognostic index, an lCMRO2 decrease to a level below about 70% of the controlateral value indicating that the necrosis is spontaneously irreparable. These results are discussed in the light of published data

  2. Reduced cerebral blood flow and oxygen metabolism in extremely preterm neonates with low-grade germinal matrix- intraventricular hemorrhage

    Science.gov (United States)

    Lin, Pei-Yi; Hagan, Katherine; Fenoglio, Angela; Grant, P. Ellen; Franceschini, Maria Angela

    2016-01-01

    Low-grade germinal matrix-intraventricular hemorrhage (GM-IVH) is the most common complication in extremely premature neonates. The occurrence of GM-IVH is highly associated with hemodynamic instability in the premature brain, yet the long-term impact of low-grade GM-IVH on cerebral blood flow and neuronal health have not been fully investigated. We used an innovative combination of frequency-domain near infrared spectroscopy and diffuse correlation spectroscopy (FDNIRS-DCS) to measure cerebral oxygen saturation (SO2) and an index of cerebral blood flow (CBFi) at the infant’s bedside and compute an index of cerebral oxygen metabolism (CMRO2i). We enrolled twenty extremely low gestational age (ELGA) neonates (seven with low-grade GM-IVH) and monitored them weekly until they reached full-term equivalent age. During their hospital stay, we observed consistently lower CBFi and CMRO2i in ELGA neonates with low-grade GM-IVH compared to neonates without hemorrhages. Furthermore, lower CBFi and CMRO2i in the former group persists even after the resolution of the hemorrhage. In contrast, SO2 does not differ between groups. Thus, CBFi and CMRO2i may have better sensitivity than SO2 in detecting GM-IVH-related effects on infant brain development. FDNIRS-DCS methods may have clinical benefit for monitoring the evolution of GM-IVH, evaluating treatment response, and potentially predicting neurodevelopmental outcome. PMID:27181339

  3. Reduced cerebral blood flow and oxygen metabolism in extremely preterm neonates with low-grade germinal matrix- intraventricular hemorrhage

    Science.gov (United States)

    Lin, Pei-Yi; Hagan, Katherine; Fenoglio, Angela; Grant, P. Ellen; Franceschini, Maria Angela

    2016-05-01

    Low-grade germinal matrix-intraventricular hemorrhage (GM-IVH) is the most common complication in extremely premature neonates. The occurrence of GM-IVH is highly associated with hemodynamic instability in the premature brain, yet the long-term impact of low-grade GM-IVH on cerebral blood flow and neuronal health have not been fully investigated. We used an innovative combination of frequency-domain near infrared spectroscopy and diffuse correlation spectroscopy (FDNIRS-DCS) to measure cerebral oxygen saturation (SO2) and an index of cerebral blood flow (CBFi) at the infant’s bedside and compute an index of cerebral oxygen metabolism (CMRO2i). We enrolled twenty extremely low gestational age (ELGA) neonates (seven with low-grade GM-IVH) and monitored them weekly until they reached full-term equivalent age. During their hospital stay, we observed consistently lower CBFi and CMRO2i in ELGA neonates with low-grade GM-IVH compared to neonates without hemorrhages. Furthermore, lower CBFi and CMRO2i in the former group persists even after the resolution of the hemorrhage. In contrast, SO2 does not differ between groups. Thus, CBFi and CMRO2i may have better sensitivity than SO2 in detecting GM-IVH-related effects on infant brain development. FDNIRS-DCS methods may have clinical benefit for monitoring the evolution of GM-IVH, evaluating treatment response, and potentially predicting neurodevelopmental outcome.

  4. Effects of race and sex on cerebral hemodynamics, oxygen delivery and blood flow distribution in response to high altitude

    Science.gov (United States)

    Liu, Jie; Liu, Yang; Ren, Li-Hua; Li, Li; Wang, Zhen; Liu, Shan-Shan; Li, Su-Zhi; Cao, Tie-Sheng

    2016-08-01

    To assess racial, sexual, and regional differences in cerebral hemodynamic response to high altitude (HA, 3658 m). We performed cross-sectional comparisons on total cerebral blood flow (TCBF = sum of bilateral internal carotid and vertebral arterial blood flows = QICA + QVA), total cerebrovascular resistance (TCVR), total cerebral oxygen delivery (TCOD) and QVA/TCBF (%), among six groups of young healthy subjects: Tibetans (2-year staying) and Han (Han Chinese) at sea level, Han (2-day, 1-year and 5-year) and Tibetans at HA. Bilateral ICA and VA diameters and flow velocities were derived from duplex ultrasonography; and simultaneous measurements of arterial pressure, oxygen saturation, and hemoglobin concentration were conducted. Neither acute (2-day) nor chronic (>1 year) responses showed sex differences in Han, except that women showed lower TCOD compared with men. Tibetans and Han exhibited different chronic responses (percentage alteration relative to the sea-level counterpart value) in TCBF (‑17% vs. 0%), TCVR (22% vs. 12%), TCOD (0% vs. 10%) and QVA/TCBF (0% vs. 2.4%, absolute increase), with lower resting TCOD found in SL- and HA-Tibetans. Our findings indicate racial but not sex differences in cerebral hemodynamic adaptations to HA, with Tibetans (but not Han) demonstrating an altitude-related change of CBF distribution.

  5. Effects of race and sex on cerebral hemodynamics, oxygen delivery and blood flow distribution in response to high altitude.

    Science.gov (United States)

    Liu, Jie; Liu, Yang; Ren, Li-Hua; Li, Li; Wang, Zhen; Liu, Shan-Shan; Li, Su-Zhi; Cao, Tie-Sheng

    2016-01-01

    To assess racial, sexual, and regional differences in cerebral hemodynamic response to high altitude (HA, 3658 m). We performed cross-sectional comparisons on total cerebral blood flow (TCBF = sum of bilateral internal carotid and vertebral arterial blood flows = QICA + QVA), total cerebrovascular resistance (TCVR), total cerebral oxygen delivery (TCOD) and QVA/TCBF (%), among six groups of young healthy subjects: Tibetans (2-year staying) and Han (Han Chinese) at sea level, Han (2-day, 1-year and 5-year) and Tibetans at HA. Bilateral ICA and VA diameters and flow velocities were derived from duplex ultrasonography; and simultaneous measurements of arterial pressure, oxygen saturation, and hemoglobin concentration were conducted. Neither acute (2-day) nor chronic (>1 year) responses showed sex differences in Han, except that women showed lower TCOD compared with men. Tibetans and Han exhibited different chronic responses (percentage alteration relative to the sea-level counterpart value) in TCBF (-17% vs. 0%), TCVR (22% vs. 12%), TCOD (0% vs. 10%) and QVA/TCBF (0% vs. 2.4%, absolute increase), with lower resting TCOD found in SL- and HA-Tibetans. Our findings indicate racial but not sex differences in cerebral hemodynamic adaptations to HA, with Tibetans (but not Han) demonstrating an altitude-related change of CBF distribution. PMID:27503416

  6. Alteration in regional tissue oxygenation of preterm infants during placement in the semi-upright seating position.

    Science.gov (United States)

    Petrova, Anna; Mehta, Rajeev

    2015-01-01

    We investigated whether the cerebral (rSO2-C %) and renal (rSO2-R %) tissue oxygenation of preterm infants is altered by repositioning from the supine to semi-upright position for pre-discharge car seat testing. Near-infrared spectroscopy was used to measure rSO2-C and rSO2-R, which were recorded simultaneously with vital signs in 15 preterm infants for 30 minutes in supine, 60 minutes in the semi-upright (at 45 degrees in a car seat), and 30 minutes in the post-semi-upright (supine) position. Changes in rSO2-C and SO2-R were mostly within 1 Standard Deviation (SD) of baseline mean levels in the supine position. Decrease in rSO2-C and rSO2-R (more than 1SD below baseline mean) was recorded in 26.7% and 6.6% of infants respectively, which persisted even after adjustment for variation in heart and respiratory rate, and pulse oximeter measured oxygen saturation (P, 0.0001). Re-positioning the infants from the car seat to supine position was associated with normalization of the rSO2-C. Alteration in rSO2-C and rSO2-R in a car seat was independent from the gestational and post-conception age, weight and presence of anemia. We concluded that approximately one-third of preterm infants show minor reduction of cerebral tissue oxygenation in the semi-upright (car seat) position. PMID:25661986

  7. Brazilein inhibits neuronal inflammation induced by cerebral ischemia and oxygen-glucose deprivation through targeting NOD2 expression.

    Science.gov (United States)

    Yan, Xiao-Jin; Chai, Yu-Shuang; Yuan, Zhi-Yi; Wang, Xin-Pei; Jiang, Jing-Fei; Lei, Fan; Xing, Dong-Ming; DU, Li-Jun

    2016-05-01

    Brazilein is reported to have immunosuppressive effect on cardiovascular and cerebral-vascular diseases. The essential roles of innate immunity in cerebral ischemia are increasingly identified, but no studies concerning the influence of brazilein on the innate immunity receptors have been reported. The present study was designed to investigate the regulation of NOD2 (Nucleotide-binding oligomerization domain-containing protein 2) by brazilein for its protection of neuron in cerebral ischemia in vivo and oxygen-glucose deprivation in vitro. The results showed that brazilein could reverse the elevated expression of NOD2 and TNFα (tumor necrosis factor alpha) elicited by cerebral ischemia and reperfusion. This reduction could also be detected in normal mice and C17.2 cells, indicating that this suppressive effect of brazilein was correlated with NOD2. The results from GFP reporter plasmid assay suggested brazilein inhibited NOD2 gene transcription. In conclusion, brazilein could attenuate NOD2 and TNFα expression in cerebral ischemia and NOD2 may be one possible target of brazilein for its immune suppressive effect in neuro-inflammation. PMID:27478098

  8. 高压氧治疗脑梗死疗效观察%Observation of therapeutic effect of hyperbaric oxygen on cerebral infarction

    Institute of Scientific and Technical Information of China (English)

    马维艳; 杨丽

    2002-01-01

    Background:Hypoxia and ischemia resulting from cerebral infarction can further cause a series of pathological changes such as hydrocephallus.Drug therapy can improve cerebral blood circulation and enhance flow volume and decrease infarction area.If hyperbaric oxygen is added,pathophysiological changes such as ischemia and hypoxia can be improved and normal metabolism of brain cells be restored.

  9. MRI-based methods for quantification of the cerebral metabolic rate of oxygen.

    Science.gov (United States)

    Rodgers, Zachary B; Detre, John A; Wehrli, Felix W

    2016-07-01

    The brain depends almost entirely on oxidative metabolism to meet its significant energy requirements. As such, the cerebral metabolic rate of oxygen (CMRO2) represents a key measure of brain function. Quantification of CMRO2 has helped elucidate brain functional physiology and holds potential as a clinical tool for evaluating neurological disorders including stroke, brain tumors, Alzheimer's disease, and obstructive sleep apnea. In recent years, a variety of magnetic resonance imaging (MRI)-based CMRO2 quantification methods have emerged. Unlike positron emission tomography - the current "gold standard" for measurement and mapping of CMRO2 - MRI is non-invasive, relatively inexpensive, and ubiquitously available in modern medical centers. All MRI-based CMRO2 methods are based on modeling the effect of paramagnetic deoxyhemoglobin on the magnetic resonance signal. The various methods can be classified in terms of the MRI contrast mechanism used to quantify CMRO2: T2*, T2', T2, or magnetic susceptibility. This review article provides an overview of MRI-based CMRO2 quantification techniques. After a brief historical discussion motivating the need for improved CMRO2 methodology, current state-of-the-art MRI-based methods are critically appraised in terms of their respective tradeoffs between spatial resolution, temporal resolution, and robustness, all of critical importance given the spatially heterogeneous and temporally dynamic nature of brain energy requirements. PMID:27089912

  10. Mitochondrial regulation of reactive oxygen species (ROS) production-Unexpected observations in early postnatal cerebral vasculature.

    Science.gov (United States)

    Wolf, S; Mattheis, A; Laufs, U; Meier, C; Tschernig, T

    2016-07-01

    Nicotinamide-nucleotide-transhydrogenase (Nnt) is a mitochondrial protein. It is altered and functionally lacking in the C57BL/6J sub-strain. This leads to the generation of more radical oxygen species than in the C57BL/6N sub-strain. During studies on the effect of Nnt in perinatal hypoxia the cerebral vasculature was investigated in postnatal day 9 mice using post mortem arterial filling with silicone rubber compounds. Surprisingly, the tiny vessels were no longer uniformly filled and a bleb-like pattern occurred in both sub-strains. Furthermore, considerably more bleb-like spots were observed in the C57Bl/6J sub-strain than in the C57Bl/6N sub-strain. These blebs might be the result of feathery vessels bursting. It remains unclear how the mechanisms in the used strains differ. Nnt might influence the vascular structure or its development and mechanisms and should be investigated further. PMID:26724498

  11. Protective effects of l-glutamine against toxicity of deltamethrin in the cerebral tissue

    Science.gov (United States)

    Varol, Sefer; Özdemir, Hasan Hüseyin; Çevik, Mehmet Uğur; Altun, Yaşar; Ibiloğlu, Ibrahim; Ekinci, Aysun; Ibiloğlu, Aslıhan Okan; Balduz, Metin; Arslan, Demet; Tekin, Recep; Aktar, Fesih; Aluçlu, Mehmet Ufuk

    2016-01-01

    Background Deltamethrin (DLM) is a broad-spectrum synthetic dibromo-pyrethroid pesticide that is widely used for agricultural and veterinary purposes. However, human exposure to the pesticide leads to neurotoxicity. Glutamine is one of the principal, free intracellular amino acids and may also be an antioxidant. This study was undertaken in order to examine the neuroprotective and antioxidant potential of l-glutamine against DLM toxicity in female Wistar albino rats. Materials and methods The rats were divided into the following groups (n=10): Group I: control (distilled water; 10 mL/kg, po one dose), Group II: l-glutamine (1.5 g/kg, po one dose), Group III: DLM (35 mg/kg, po one dose), and Group IV: DLM (35 mg/kg, po one dose) and l-glutamine (1.5 g/kg, po one dose after 4 hours). Total oxidant status (TOS), total antioxidant status (TAS), tumor necrosis factor-α, interleukin (IL)-1β, and IL-6 levels and apoptosis were evaluated in brain tissue. Results DLM-treated animals had a significant increase in brain biochemical parameters, as well as TOS and TAS. Furthermore, the histopathological examination showed neuronal cell degeneration in the cerebral tissue. l-Glutamine treatment decreased the elevated brain levels of TOS and neuronal cell degeneration. There was no difference in tumor necrosis factor-α, IL-1β, and IL-6 levels between the groups. Conclusion l-Glutamine may reduce the toxic effects of DLM in the cerebral tissue through antioxidant properties. PMID:27143900

  12. The effect of Sub-maximal exercise-rehabilitation program on cardio-respiratory endurance indexes and oxygen pulse in patients with spastic cerebral palsy

    OpenAIRE

    M Izadi; F. Nazem; M Hazavehei

    2006-01-01

    Background: Physical or cardio-respiratory fitness are of the best important physiological variables in children with cerebral palsy (CP), but the researches on exercise response of individuals with CP are limited. Our aim was to determine the effect of sub-maximal rehabilitation program (aerobic exercise) on maximal oxygen uptake, oxygen pulse and cardio- respiratory physiological variables of children with moderate to severe spastic cerebral palsy diplegia and compare with able-bodied child...

  13. Variations of brain edema and neurological function of rat models of cerebral infarction after hyperbaric oxygen therapy%高压氧干预脑梗死模型大鼠脑水肿及神经功能变化

    Institute of Scientific and Technical Information of China (English)

    田烜

    2015-01-01

    背景:研究认为,高压氧有较好保护脑神经和脑细胞的作用,应用高压氧可使氧分压快速弥撒到相对缺氧的脑组织中,增加脑组织的血氧含量,促进脑水肿及脑神经功能的恢复。目的:观察大脑中动脉阻塞造模后高压氧干预对大鼠脑梗死组织水肿的影响,并探讨其对脑梗死大鼠神经功能保护的可能作用机制。方法:成年雌性SD大鼠65只,造模成功60只,随机区组法分为假手术组、脑梗死组、高压氧组,每组20只,按照线栓线法建立大鼠大脑中动脉阻塞脑梗死模型。造模后3 d,通过TUNEL法检测各实验组大鼠脑梗死区神经细胞的凋亡情况。伤后72 h通过RT-PCR、Western blot检测脑梗死区周围AQP4/9、基质金属蛋白酶9/2基因转录和蛋白的表达,通过苏木精-伊红染色观察脑梗死区病理组织形态学变化,通过免疫组织化学法检测胶质纤维酸性蛋白的表达量,高压氧干预后24 h,3 d及伤后1、2周行Longa行为学评分,检测神经功能的损伤情况。结果与结论:①高压氧组Longa行为学评分在治疗后1,2 d均较脑梗死组显著降低(P <0.05)。②造模后3 d高压氧组细胞凋亡指数均明显低于脑梗死组(P<0.05)。③造模后72 h,与脑梗死组相比高压氧组AQP4/9、基质金属蛋白酶9/2基因和蛋白表达均较显著降低(P<0.05)。结果提示高压氧治疗通过减少大鼠脑梗死区神经细胞的凋亡和降低脑组织水肿,对脑梗死起到保护作用。%BACKGROUND:Several studies have suggested that hyperbaric oxygen could better protect cranial nerve and brain cels. Hyperbaric oxygen therapy can make oxygen partial pressure rapidly diffusing toward relatively hypoxic brain tissue, so as to increase blood oxygen content in the brain tissue, reduce brain edema and promote the recovery of brain function. OBJECTIVE: To observe the effects of hyperbaric oxygen therapy on brain tissue

  14. Near-infrared spectroscopy monitoring of cerebral oxygen during assisted ventilation

    OpenAIRE

    Booth, Erin A.; Dukatz, Christopher; Sood, Beena G.; Wider, Michael

    2011-01-01

    Background: Changes in the arterial partial pressure of CO2 (PaCO2) has a direct though transient effect on the cerebral vasculature and cerebral circulation. Decreased PaCO2 levels lead to vasoconstriction and can result in dangerously low levels of cerebral perfusion that resolve in 4–6 h. It is currently believed that perfusion abnormalities contribute to intraventricular hemorrhage (IVH) and periventricular leukomalacia (PVL) in the neonate. PaCO2-induced vasoconstriction may contribute t...

  15. Tissue oxygenation and muscular substrate turnover in two subjects with high hemoglobin oxygen affinity.

    OpenAIRE

    Wranne, B; Berlin, G; Jorfeldt, L; Lund, N.

    1983-01-01

    Oxygen transport to and substrate turnover in leg muscle were studied at rest and during light and heavy upright bicycle exercise in two brothers with a hereditary hemoglobinopathy associated with high oxygen affinity (P50 = 13 mmHg). Femoral venous oxygen tension was below normal and femoral venous oxygen saturation above normal at rest and during exercise. Thus, the arterial-femoral venous oxygen saturation difference was decreased. Despite a compensatory increase in hemoglobin concentratio...

  16. Chronic Aldosterone Administration Causes NOX2-Mediated Increases In Reactive Oxygen Species Production and Endothelial Dysfunction in the Cerebral Circulation

    Science.gov (United States)

    CHRISSOBOLIS, Sophocles; DRUMMOND, Grant R.; FARACI, Frank M.; SOBEY, Christopher G.

    2014-01-01

    Objective An elevated plasma aldosterone level is an independent cardiovascular risk factor. Although excess aldosterone promotes cardiovascular disease, no studies have examined the effect of increased plasma aldosterone on the cerebral circulation. A major source of vascular reactive oxygen species (ROS) during cardiovascular disease is the NADPH oxidases. Because NOX2-containing NADPH oxidase (NOX2 oxidase) is highly expressed in cerebral endothelium, we postulated that it might contribute to ROS generation and vascular dysfunction in response to aldosterone. Here we examined the effect of aldosterone and NOX2 oxidase on ROS production and endothelial dysfunction in the cerebral circulation, and whether the effects of aldosterone are exacerbated in aged mice. Methods and Results In adult (average age ~24–25 wk) wild-type (WT) and Nox2-deficient (Nox2−/y) mice, neither vehicle nor aldosterone (0.28 mg/kg/day for 14 days) affected blood pressure (measured using tail-cuff). By contrast, aldosterone treatment reduced dilation of the basilar artery (measured using myography) to the endothelium-dependent agonist acetylcholine in WT mice (P0.05). Aldosterone increased basal and phorbol-dibutyrate stimulated superoxide production (measured using L-012-enhanced chemiluminesence) in cerebral arteries from WT but not Nox2−/y mice. In aged WT mice (average age ~70 wk), aldosterone treatment increased blood pressure, but had a similar effect on cerebral artery superoxide levels as in adult WT mice. Conclusions These data indicate that NOX2 oxidase mediates aldosterone-induced increases in ROS production and endothelial dysfunction in cerebral arteries from adult mice independently of blood pressure changes. Aldosterone-induced hypertension is augmented during aging. PMID:24991871

  17. Diastolic myocardial dysfunction by tissue Doppler imaging predicts mortality in patients with cerebral infarction

    DEFF Research Database (Denmark)

    Olsen, Flemming J; Jørgensen, Peter G; Møgelvang, Rasmus;

    2015-01-01

    Several clinical prediction score models have been investigated for predicting mortality in patients with cerebral infarction. However, none of these include echocardiographic measures. Our objective was to evaluate the prognostic value of tissue Doppler imaging (TDI) of the myocardium in patients......-statistics and reclassification analysis were performed for global and segmental e'. During a median follow-up of 3 years 42 patients died. Patients who died had significantly impaired systolic and diastolic function (determined by LVEF and E/e'). The risk of dying increased with decreasing global e', being...... approximately 13 times higher for patients in the lowest tertile compared to patients in the highest tertile (HR 13.4 [3.2;56.3], p < 0.001). Patients with significantly impaired global e' showed increased mortality after multivariable adjustment for: LVEF, E/e', age, gender, heart failure, chronic obstructive...

  18. Can the cerebral metabolic rate of oxygen be estimated with near-infrared spectroscopy?

    International Nuclear Information System (INIS)

    We have measured the changes in oxy-haemoglobin and deoxy-haemoglobin in the adult human brain during a brief finger tapping exercise using near-infrared spectroscopy (NIRS). The cerebral metabolic rate of oxygen (CMRO2) can be estimated from these NIRS data provided certain model assumptions. The change in CMRO2 is related to changes in the total haemoglobin concentration, deoxy-haemoglobin concentration and blood flow. As NIRS does not provide a measure of dynamic changes in blood flow during brain activation, we relied on a Windkessel model that relates dynamic blood volume and flow changes, which has been used previously for estimating CMRO2 from functional magnetic resonance imaging (fMRI) data. Because of the partial volume effect we are unable to quantify the absolute changes in the local brain haemoglobin concentrations with NIRS and thus are unable to obtain an estimate of the absolute CMRO2 change. An absolute estimate is also confounded by uncertainty in the flow-volume relationship. However, the ratio of the flow change to the CMRO2 change is relatively insensitive to these uncertainties. For the finger tapping task, we estimate a most probable flow-consumption ratio ranging from 1.5 to 3 in agreement with previous findings presented in the literature, although we cannot exclude the possibility that there is no CMRO2 change. The large range in the ratio arises from the large number of model parameters that must be estimated from the data. A more precise estimate of the flow-consumption ratio will require better estimates of the model parameters or flow information, as can be provided by combining NIRS with fMRI

  19. Can the cerebral metabolic rate of oxygen be estimated with near-infrared spectroscopy?

    Science.gov (United States)

    Boas, D. A.; Strangman, G.; Culver, J. P.; Hoge, R. D.; Jasdzewski, G.; Poldrack, R. A.; Rosen, B. R.; Mandeville, J. B.

    2003-08-01

    We have measured the changes in oxy-haemoglobin and deoxy-haemoglobin in the adult human brain during a brief finger tapping exercise using near-infrared spectroscopy (NIRS). The cerebral metabolic rate of oxygen (CMRO2) can be estimated from these NIRS data provided certain model assumptions. The change in CMRO2 is related to changes in the total haemoglobin concentration, deoxy-haemoglobin concentration and blood flow. As NIRS does not provide a measure of dynamic changes in blood flow during brain activation, we relied on a Windkessel model that relates dynamic blood volume and flow changes, which has been used previously for estimating CMRO2 from functional magnetic resonance imaging (fMRI) data. Because of the partial volume effect we are unable to quantify the absolute changes in the local brain haemoglobin concentrations with NIRS and thus are unable to obtain an estimate of the absolute CMRO2 change. An absolute estimate is also confounded by uncertainty in the flow-volume relationship. However, the ratio of the flow change to the CMRO2 change is relatively insensitive to these uncertainties. For the finger tapping task, we estimate a most probable flow-consumption ratio ranging from 1.5 to 3 in agreement with previous findings presented in the literature, although we cannot exclude the possibility that there is no CMRO2 change. The large range in the ratio arises from the large number of model parameters that must be estimated from the data. A more precise estimate of the flow-consumption ratio will require better estimates of the model parameters or flow information, as can be provided by combining NIRS with fMRI.

  20. Dissolution of emboli in rats with experimental cerebral thromboembolism by recombinant human tissue plasminogen activator (TD-2061)

    International Nuclear Information System (INIS)

    Tissue plasminogen activator (t-PA) is frequently administered clinically as thrombolytic therapy. We injected recombinant t-PA into rats with cerebral 125I-labeled blood clot emboli to evaluate the dissolutive effect of recombinant human single-chain t-PA (rt-PA; TD-2061) on such emboli and to examine the possibility of improving neurological damage in patients with cerebral thrombosis. When rt-PA was given intravenously at a dose of 350,000 IU/kg 2 minutes before embolization, radioactivity in the affected cerebral hemisphere decreased to 20% of that in the vehicle control 2 hours after embolization. A significant decrease in radioactivity in the cerebral hemisphere was also found on the administration of 700,000 IU/kg of rt-PA 30 or 60 minutes after embolization, but not when rt-PA was administered 2 minutes after embolization. Marked inhibition of abnormal behavior such as hemiplegia was seen on treatment with rt-PA 2 minutes before embolization, but not at all when rt-PA treatment was given 30 or 60 minutes after embolization. The findings suggest that rt-PA can dissolve blood clot emboli in cerebral vessels and that prompt thrombolytic therapy is important to minimize neurological dysfunction in cases of cerebral thromboembolism

  1. The changes of oxygen extraction fraction and cerebral blood flow of brain parenchyma in patients with unilateral cerebral vessel stenosis: initial experience of the quantitative measurements

    International Nuclear Information System (INIS)

    Objective: Using gradient-echo sampling of spin-echo (GESSE) sequence to study the change of oxygen extraction fraction (OEF) in patients with unilateral cerebral vessel stenosis and the relationship between OEF and cerebral blood flow (CBF). Methods: Eight normal volunteers and 16 patients with unilateral cerebral vessel stenosis were enrolled in this study. Written informed consents were obtained from all subjects. Routine MRI, GESSE and arterial spin labeling (ASL) sequences were performed for all patients. Raw data from GESSE and VE-ASL sequences were transferred to PC to conduct postprocessing. To obtain quantitative OEF and CBF of the brain parenchyma, 6 ROIs were placed respectively in the anterior, middle and posterior part of both hemispheres. The relative CBF (rCBF) was defined as the ratio of CBF of ischemic hemisphere to that of contralateral hemisphere. T test was used for statistics. Results: The mean value and normal range of OEF in the volunteers were 0.318±0.023 and 0.272-0.364, respectively. In the 16 patients with unilateral cerebral vessel stenosis, 8 patients had ROIs with greater OEF iri unilateral hemisphere than those in contralateral hemisphere. These cases presented multiple intracranial main arterial stenoses in digital subtraction angiography (DSA) or MR angiography (MRA) examination. The other 8 patients had normal OEF in all ROIs. And they only had single arterial stenosis in DSA or MRA. Set rCBF = 0.50 as a dividing point, the mean OEF value was 0.397±0.010 in the patients with rCBF < 0.50. In the patients with rCBF ≥ 0.5, the mean OEF value was 0.325± 0.028. The difference between the two groups was statistically significant (t=-8.840, P=0.000). Conclusion: Patients with chronic cerebral ischemia may present with various hemodynamic impairment. The more CBF decreases, the more OEF increases. Those with increased OEF tended to have more than one lesion in the major intracranial arteries. (authors)

  2. Cerebral blood flow and oxygen metabolism in senile dementia of Alzheimer's type and vascular dementia with deep white matter changes

    International Nuclear Information System (INIS)

    Regional cerebral blood flow (rCBF), cerebral metabolic rate of oxygen (rCMRO2), oxygen extraction fraction (rOEF), and cerebral blood volume (rCBV) were investigated using positron emission tomography (PET) in 16 patients with senile dementia of Alzheimer's type (SDAT), and compared with those of 6 nondemented and 3 demented patients with deep white matter high signal (DWMH) on T2-weighted MRI and 6 controls. rCBF, rCMRO2 and rCBV were determined using C15O2, 15O2 and C15O, respectively. rCBF and CMRO2 were significantly decreased in the frontal, parietal and temporal cortex (P 2 was significantly reduced in only the frontal and temporal cortex of demented patients (P < 0.05). rOEF was significantly increased in the parietal cortex of patients with SDAT and in the white matter of patients with SDAT or DWMH (P < 0.05), and the increase in the frontal white matter significantly paralleled the progression of dementia in patients with SDAT (P < 0.05). rCBV was significantly decreased in the parietal and temporal cortex of patients with SDAT (P < 0.05), but not in any areas of those with DWMH. (orig.)

  3. Ultrastructure of focal cerebral cortex tissue from rats with focal cortical dysplasia

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    BACKGROUND:Developing a model of focal cortical dysplasia in microgyrus and observing the ultrastructure of focal tissue is of important significance for analyzing the pathology of cortical developmental disorder and the factors of structural changes. OBJECTIVE:This study was to observe the pathological characteristics of focal tissue around the microgyrus of rats with cortical developmental disorder using an electron microscope,so as to analyze the causes associated with cerebral cortical developmental disorder. DESIGN:A randomized controlled animal experiment. SETTING:The First Affiliated Hospital of Chongqing Medical University. MATERIALS:This study was carried out in the Chongqing Key Laboratory of Neurology,Room for Electron Microscope of Chongqing Medical University,and Laboratory Animal Center,Research Institute of Surgery,Daping Hospital,Third Military Medical University of Chinese PLA between January 2004 and August 2006.Eighteen healthy newborn male Wistar rats,weighing 3.0 - 6.0 g,provided by the Laboratory Animal Center,Daping Hospital,Third Military Medical University of Chinese PLA,were involved in this study.The protocol was carried out in accordance with animal ethics guidelines for the use and care of animals.Probes (Chongqing Wire & Cable Factory,China) were made of copper core wire with diameter of 1 mm.METHODS:The rats were randomly divided into 3 groups with 6 in each:normal control group,liquid nitrogen injured group and sham-operation group.①In the liquid nitrogen injured group,a blunt probe frozen by liquid nitrogen was placed on fronto-parietal crinial bone of rats for 8 s.A 3 - 5 cm of microgyrus was induced in the unilateral cerebral sensory cortical area.In the sham-operation group,probe was placed at the room temperature.In the normal control group,rats were untouched.② The conscious state and electrical activity of brain of rats in each group were observed.③ 2-3 mm thickness of hippocampal tissue with coronary section was taken

  4. Measuring brain tissue oxygenation under oxidative stress by ESR/MR dual imaging system

    International Nuclear Information System (INIS)

    The in vivo measurement of oxygen in tissues is of great interest because of oxygen's fundamental role in life. Many methods have been developed for such measurement, but all have been limited, especially with regard to repeated measurement, degree of invasiveness, and sensitivity. We describe electron spin resonance (ESR) oximetry with paramagnetic oxygen-sensing probe for in vivo measurement of oxygen in brain tissues by homemade ESR/MR dual imaging spectroscopy. Lithium 5, 9, 14, 18, 23, 27, 32, 36-octan-butoxy-2, 3-naphthalocyanine (LiNc-BuO) radical was employed as the solid oxygen-sensing probe, and we confirmed its ability to report partial pressure of oxygen (pO2) in brain tissues of live animals under normal and pathological conditions for more than a month. pO2 measurements could also be made repeatedly on the same animal and at the same location. The implantation site of LiNc-BuO in examined rats was verified by 0.5T magnetic resonance (MR) imaging. Septic-shock rats were used to monitor tissue oxygenation during pathological state. A decline in pO2 levels from severe hypotension during sepsis was detected, and generation of nitric oxide (NO) in brain tissues was confirmed by NO spin trapping. ESR oximetry using oxygen-sensing probe and NO spin-trapping can be used to monitor pO2 change and NO production simultaneously and repeatedly at the same site in examined animals. (author)

  5. An Asymptotic Study for the Steady Model of Oxygen Diffusion in Tissue Region

    Directory of Open Access Journals (Sweden)

    Kartika Yulianti

    2012-07-01

    Full Text Available Oxygen plays an important role in cell metabolism inside a human's body. The transfer of oxygen from blood to tissues takes place in capillaries through the diffusion process. A capillary-tissue region is usually represented by so called the Krogh Cylinder arrangement in which the distribution of the oxygen concentration in a tissue region leads to a diffusion equation with oxygen consumption rates following the Michaelis-Menten kinetics. In this paper, we restrict ourselves to consider the steady case and solve the equation analytically, by means of the asymptotic expansions, for a particular limit of the oxygen consumption rate. Results show that there exists a critical ratio between supply and consumption of oxygen in tissue region in order to fulfill cell’s oxygen requirements. Above this critical ratio, we also find a critical distance in the tissue region above which the oxygen concentration vanishes. We also compare our asymptotic results with numerical simulations which are both quite in agreement.

  6. Systematic review of near-infrared spectroscopy determined cerebral oxygenation during non-cardiac surgery

    DEFF Research Database (Denmark)

    Nielsen, Henning B

    2014-01-01

    . Shoulder arthroscopy in the beach chair and carotid endarterectomy with clamped internal carotid artery (ICA) also cause pronounced cerebral desaturation. A >20% reduction in rScO2 coincides with indices of regional and global cerebral ischemia during carotid endarterectomy. Following thoracic surgery......, major orthopedic, and abdominal surgery the occurrence of postoperative cognitive dysfunction (POCD) might be related to intraoperative cerebral desaturation. In conclusion, certain non-cardiac surgical procedures is associated with an increased risk for the occurrence of rScO2. Evidence for an...

  7. Protective effects of L-glutamine against toxicity of deltamethrin in the cerebral tissue

    Directory of Open Access Journals (Sweden)

    Varol S

    2016-04-01

    Full Text Available Sefer Varol, Hasan Hüseyin Özdemir, Mehmet Uğur Çevik, Yaşar Altun, Ibrahim Ibiloğlu, Aysun Ekinci, Aslıhan Okan Ibiloğlu, Metin Balduz, Demet Arslan, Recep Tekin, Fesih Aktar, Mehmet Ufuk Aluçlu Department of Neurology, Faculty of Medicine, Dicle University, Diyarbakir, Turkey Background: Deltamethrin (DLM is a broad-spectrum synthetic dibromo-pyrethroid pesticide that is widely used for agricultural and veterinary purposes. However, human exposure to the pesticide leads to neurotoxicity. Glutamine is one of the principal, free intracellular amino acids and may also be an antioxidant. This study was undertaken in order to examine the neuroprotective and antioxidant potential of L-glutamine against DLM toxicity in female Wistar albino rats. Materials and methods: The rats were divided into the following groups (n=10: Group I: control (distilled water; 10 mL/kg, po one dose, Group II: L-glutamine (1.5 g/kg, po one dose, Group III: DLM (35 mg/kg, po one dose, and Group IV: DLM (35 mg/kg, po one dose and L-glutamine (1.5 g/kg, po one dose after 4 hours. Total oxidant status (TOS, total antioxidant status (TAS, tumor necrosis factor-α, interleukin (IL-1β, and IL-6 levels and apoptosis were evaluated in brain tissue. Results: DLM-treated animals had a significant increase in brain biochemical parameters, as well as TOS and TAS. Furthermore, the histopathological examination showed neuronal cell degeneration in the cerebral tissue. L-Glutamine treatment decreased the elevated brain levels of TOS and neuronal cell degeneration. There was no difference in tumor necrosis factor-α, IL-1β, and IL-6 levels between the groups. Conclusion: L-Glutamine may reduce the toxic effects of DLM in the cerebral tissue through antioxidant properties. Keywords: deltamethrin, L-glutamine, rat

  8. Tissue-type plasminogen activator induces synaptic vesicle endocytosis in cerebral cortical neurons.

    Science.gov (United States)

    Yepes, M; Wu, F; Torre, E; Cuellar-Giraldo, D; Jia, D; Cheng, L

    2016-04-01

    The release of the serine proteinase tissue-type plasminogen activator (tPA) from the presynaptic terminal of cerebral cortical neurons plays a central role in the development of synaptic plasticity, adaptation to metabolic stress and neuronal survival. Our earlier studies indicate that by inducing the recruitment of the cytoskeletal protein βII-spectrin and voltage-gated calcium channels to the active zone, tPA promotes Ca(2+)-dependent translocation of synaptic vesicles (SVs) to the synaptic release site where they release their load of neurotransmitters into the synaptic cleft. Here we used a combination of in vivo and in vitro experiments to investigate whether this effect leads to depletion of SVs in the presynaptic terminal. Our data indicate that tPA promotes SV endocytosis via a mechanism that does not require the conversion of plasminogen into plasmin. Instead, we show that tPA induces calcineurin-mediated dynamin I dephosphorylation, which is followed by dynamin I-induced recruitment of the actin-binding protein profilin II to the presynaptic membrane, and profilin II-induced F-actin formation. We report that this tPA-induced sequence of events leads to the association of newly formed SVs with F-actin clusters in the endocytic zone. In summary, the data presented here indicate that following the exocytotic release of neurotransmitters tPA activates the mechanism whereby SVs are retrieved from the presynaptic membrane and endocytosed to replenish the pool of vesicles available for a new cycle of exocytosis. Together, these results indicate that in murine cerebral cortical neurons tPA plays a central role coupling SVs exocytosis and endocytosis. PMID:26820595

  9. The Effect of Equal Ratio Ventilation on Oxygenation, Respiratory Mechanics, and Cerebral Perfusion Pressure During Laparoscopy in the Trendelenburg Position.

    Science.gov (United States)

    Jo, Youn Yi; Kim, Ji Young; Chang, Young Jin; Lee, Sehwan; Kwak, Hyun Jeong

    2016-06-01

    The aim of this study was to investigate the effects of equal ratio ventilation (ERV) on oxygenation, respiratory mechanics, and the cerebral perfusion pressure during pneumoperitoneum in the Trendelenburg position. Thirty patients undergoing laparoscopic low anterior resection (25 to 65 y) were enrolled. Mechanical ventilator was set to volume-controlled mode at an inspiratory to expiratory (I:E) ratio of 1:2 with a tidal volume of 8 mL/kg of ideal body weight with a 5 cm H2O positive end-expiratory pressure. Twenty minutes after pneumoperitoneum in the Trendelenburg position, the I:E ratio was changed to 1:1 for 20 minutes and then restored to 1:2. No significant changes in arterial oxygen tension and respiratory compliance after adopting ERV. Mean arterial pressure and cerebral perfusion pressure decreased significantly over time after adopting the Trendelenburg position during pneumoperitoneum (P=0.014 and 0.005, respectively). In conclusion, there was no improvement in oxygenation or respiratory mechanics with ERV. PMID:27258912

  10. Coupling of cerebral blood flow and oxygen metabolism is conserved for chromatic and luminance stimuli in human visual cortex.

    Science.gov (United States)

    Leontiev, Oleg; Buracas, Giedrius T; Liang, Christine; Ances, Beau M; Perthen, Joanna E; Shmuel, Amir; Buxton, Richard B

    2013-03-01

    The ratio of the changes in cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO(2)) during brain activation is a critical determinant of the magnitude of the blood oxygenation level dependent (BOLD) response measured with functional magnetic resonance imaging (fMRI). Cytochrome oxidase (CO), a key component of oxidative metabolism in the mitochondria, is non-uniformly distributed in visual area V1 in distinct blob and interblob regions, suggesting significant spatial variation in the capacity for oxygen metabolism. The goal of this study was to test whether CBF/CMRO(2) coupling differed when these subpopulations of neurons were preferentially stimulated, using chromatic and luminance stimuli to preferentially stimulate either the blob or interblob regions. A dual-echo spiral arterial spin labeling (ASL) technique was used to measure CBF and BOLD responses simultaneously in 7 healthy human subjects. When the stimulus contrast levels were adjusted to evoke similar CBF responses (mean 65.4% ± 19.0% and 64.6% ± 19.9%, respectively for chromatic and luminance contrast), the BOLD responses were remarkably similar (1.57% ± 0.39% and 1.59% ± 0.35%) for both types of stimuli. We conclude that CBF-CMRO(2) coupling is conserved for the chromatic and luminance stimuli used, suggesting a consistent coupling for blob and inter-blob neuronal populations despite the difference in CO concentration. PMID:23238435

  11. Molecular and histological changes in cerebral cortex and lung tissues under the effect of tramadol treatment.

    Science.gov (United States)

    Awadalla, Eatemad A; Salah-Eldin, Alaa-Eldin

    2016-08-01

    Tramadol abuse is one of the most frequent health problems in Egypt and worldwide. In most cases, tramadol abused by men face a problem with premature ejaculation. Tramadol like other opioids induces a decrease in plasma antioxidant levels, which may reflect a failure of the antioxidant defense mechanism against oxidative damage. The present work aimed to study the possible deleterious effects of oral administration of tramadol on brain and lung tissues in rats. Twenty adult male albino rats were divided into two groups; a control administered with normal saline and tramadol-treated (40mg/kg b.w.) group for 20 successive days. At the end of experimental period, blood was collected and specimens from brains and lungs were taken for histopathological and molecular studies. Malondialdehyde (MDA), reduced glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT) activities were measured in serum of control and tramadol-treated groups. Brain and lung specimens were histopathological evaluated using light microscopy. The expression levels of apoptotic related genes; Bcl-2, Bax and Caspase-3 were study in brain and lung tissues using RT-PCR analysis. We recorded a significant increase MDA level, while antioxidant enzymes; GSH, SOD and CAT were significantly decreased after tramadol-treatment. The obtained results revealed that tramadol induced a remarkable histomorphological changes in rats' brains (cerebral cortex and hippocampus) and severe histopathological changes in rats' lung when compared to that of control. On molecular level, the expression of the pro-apoptotic Bax and Caspase-3 showed a significant increase whereas the anti-apoptotic Bcl-2 decreased markedly indicating that tramadol is harmful at cellular level and can induce apoptotic changes in brain tissues. Our data confirmed the risk of increased oxidative stress, neuronal and pulmonary damage due to tramadol abuse. Although tramadol is reported to be effective in pain management, its toxicity should

  12. Determination of oxygen tension in the subcutaneous tissue of cosmonauts during the Salyut-6 mission

    Science.gov (United States)

    Baranski, S.; Bloszczynski, R.; Hermaszewski, M.; Kubiczkowa, J.; Piorko, A.; Saganiak, R.; Sarol, Z.; Skibniewsky, F.; Stendera, J.; Walichnowski, W.

    1982-01-01

    A polarographic technique was used to measure the oxygen tension in subcutaneous tissue of the forearm of a cosmonaut prior to, after, and on the fourth day of a space mission performed by Salut-6. A drop in the oxygen exchange rate in the peripheral tissues during weightlessness was observed. The mechanisms of this change are studied, taking into consideration the blood distribution in the organism and microcirculation disorders reflected by a decreased blood flow rate in arterial-venous junctions.

  13. Low Cerebral Oxygen Consumption and Blood Flow in Patients With Cirrhosis and an Acute Episode of Hepatic Encephalopathy

    DEFF Research Database (Denmark)

    Iversen, Peter; Bak, Lasse Kristoffer; Waagepetersen, Helle Sønderby;

    2009-01-01

    (15)O-water PET in 6 patients with liver cirrhosis and an acute episode of overt HE, 6 cirrhotic patients without HE, and 7 healthy subjects. RESULTS: Neither whole-brain CMRO(2) nor CBF differed significantly between cirrhotic patients without HE and healthy subjects, but were both significantly...... reductions in CMRO(2) and CBF in patients with HE were essentially generalized throughout the brain. CONCLUSIONS: The observations imply that reduced cerebral oxygen consumption and blood flow in cirrhotic patients with an acute episode of overt HE are associated with HE and not cirrhosis as such, and that...

  14. Oxygen regimen in the human peripheral tissue during space flights.

    Science.gov (United States)

    Haase, H; Kovalenko, E A; Vacek, A; Bobrovnickij, M P; Jarsumbeck, B; Semencov, V N; Sarol, Z; Hideg, J; Zlatarev, K

    1986-05-01

    A survey of the results of the experiment "Oxygen," carried out within the scope of the INTER-KOSMOS program in members of the permanent crews and of international visiting expeditions to the Soviet orbital station Salyut-6, is given. During the 7-day space flights of the international visiting expeditions a significant decrease in pO2ic by 3.28 kPa was observed. Local oxygen utilization reduced significantly by 0.44 kPa. During hyperventilation testing after return to earth a statistically significant decrease in the peak value by 1.39 kPa was noted. In the long-term crews of the orbital station Salyut-6 the highest decrease in pO2ic of 3.8 kPa and the absolutely lowest value of 3.4 -/+ 0.5 kPa during space flight were observed. The decrease in local oxygen utilization during the flight of 0.8 kPa/min was greater than that of the visiting crews. The results indicate the importance of investigating the dynamics of the oxygen regimen for medical control of the crew members both during the space flight and during the readaptation phase after return to earth. PMID:11542832

  15. Eigenspectra optoacoustic tomography achieves quantitative blood oxygenation imaging deep in tissues

    CERN Document Server

    Tzoumas, Stratis; Olefir, Ivan; Stangl, Stefan; Symvoulidis, Panagiotis; Glasl, Sarah; Bayer, Christine; Multhoff, Gabriele; Ntziachristos, Vasilis

    2015-01-01

    Light propagating in tissue attains a spectrum that varies with location due to wavelength-dependent fluence attenuation by tissue optical properties, an effect that causes spectral corruption. Predictions of the spectral variations of light fluence in tissue are challenging since the spatial distribution of optical properties in tissue cannot be resolved in high resolution or with high accuracy by current methods. Spectral corruption has fundamentally limited the quantification accuracy of optical and optoacoustic methods and impeded the long sought-after goal of imaging blood oxygen saturation (sO2) deep in tissues; a critical but still unattainable target for the assessment of oxygenation in physiological processes and disease. We discover a new principle underlying light fluence in tissues, which describes the wavelength dependence of light fluence as an affine function of a few reference base spectra, independently of the specific distribution of tissue optical properties. This finding enables the introd...

  16. LOCALISED MUSCLE TISSUE OXYGENATION DURING DYNAMIC EXERCISE WITH WHOLE BODY VIBRATION

    Directory of Open Access Journals (Sweden)

    Daniel Robbins

    2012-06-01

    Full Text Available Despite increasing use of whole body vibration during exercise an understanding of the exact role of vibration and the supporting physiological mechanisms is still limited. An important aspect of exercise analysis is the utilisation of oxygen, however, there have been limited studies considering tissue oxygenation parameters, particularly during dynamic whole body vibration (WBV exercise. The aim of this study was to determine the effect of adding WBV during heel raise exercises and assessing changes in tissue oxygenation parameters of the lateral gastrocnemius using Near Infra Red Spectroscopy (NIRS. Twenty healthy subjects completed ten alternating sets of 15 heel raises (vibration vs. no vibration. Synchronous oxygenation and motion data were captured prior to exercise to determine baseline levels, for the duration of the exercise and 20 sec post exercise for the recovery period. Both vibration and no vibration conditions elicited a characteristic increase in deoxyhaemoglobin and decreases in oxyhaemoglobin, total haemoglobin, tissue oxygenation index and normalised tissue haemoglobin index which are indicative of local tissue hypoxia. However, the addition of vibration elicited significantly lower (p < 0. 001 depletions in oxyhaemoglobin, total haemoglobin, normalised tissue haemoglobin index but no significant differences in deoxyhaemoglobin. These findings suggest that addition of vibration to exercise does not increase the cost of the exercise for the lateral gastrocnemius muscle, but does decrease the reduction in local muscle oxygenation parameters, potentially resulting from increased blood flow to the calf or a vasospastic response in the feet. However, further studies are needed to establish the mechanisms underlying these findings

  17. Absolute Oxygenation Metabolism Measurements Using Magnetic Resonance Imaging

    OpenAIRE

    An, Hongyu; Liu, Qingwei; Eldeniz, Cihat; Lin, Weili

    2011-01-01

    Cerebral oxygen metabolism plays a critical role in maintaining normal function of the brain. It is the primary energy source to sustain neuronal functions. Abnormalities in oxygen metabolism occur in various neuro-pathologic conditions such as ischemic stroke, cerebral trauma, cancer, Alzheimer’s disease and shock. Therefore, the ability to quantitatively measure tissue oxygenation and oxygen metabolism is essential to the understanding of pathophysiology and treatment of various diseases. T...

  18. Functional photoacoustic tomography for non-invasive imaging of cerebral blood oxygenation and blood volume in rat brain in vivo

    Science.gov (United States)

    Wang, Xueding; Xie, Xueyi; Ku, Geng; Stoica, George; Wang, Lihong V.

    2005-04-01

    Based on the multi-wavelength laser-based photoacoustic tomography, non-invasive in vivo imaging of functional parameters, including the hemoglobin oxygen saturation and the total concentration of hemoglobin, in small-animal brains was realized. The high sensitivity of this technique is based on the spectroscopic differences between oxy- and deoxy-hemoglobin while its spatial resolution is bandwidth-limited by the photoacoustic signals rather than by the optical diffusion as in optical imaging. The point-by-point distributions of blood oxygenation and blood volume in the cerebral cortical venous vessels, altered by systemic physiological modulations including hyperoxia, normoxia and hypoxia, were visualized successfully through the intact skin and skull. This technique, with its prominent intrinsic advantages, can potentially accelerate the progress in neuroscience and provide important new insights into cerebrovascular physiology and brain function that are of great significance to the neuroscience community.

  19. Development of 17O NMR approach for fast imaging of cerebral metabolic rate of oxygen in rat brain at high field

    OpenAIRE

    Zhu, Xiao-Hong; Zhang, Yi; Tian, Run-Xia; Lei, Hao; Zhang, Nanyin; Zhang, Xiaoliang; Merkle, Hellmut; Ugurbil, Kamil; Chen, Wei(Department of Physics, State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing, 100871, China)

    2002-01-01

    A comprehensive technique was developed for using three-dimensional 17O magnetic resonance spectroscopic imaging at 9.4T for rapidly imaging the cerebral metabolic rate of oxygen consumption (CMRO2) in the rat brain during a two-min inhalation of 17O2. The CMRO2 value (2.19 ± 0.14 μmol/g/min, n = 7) was determined in the rat anesthetized with α-chloralose by independent and concurrent 17O NMR measurements of cerebral H217O content, arterial input function, and cerebral perfusion. CMRO2 values...

  20. The preliminary study of Ultraviolet-Irradiated and Oxygenated Blood Transfusion Therapy(UOBT) for Experimental Cerebral Infarction of Animal Brain Model

    Institute of Scientific and Technical Information of China (English)

    Su Xiu-Chu; Feng You-Qi; Zhou gang; Wu jun-yi

    2000-01-01

    In this presented study, we have developed a photochemical model of cerebral in farction in rabbit with stable and reproducible infarct size and extent. This model is similar to the pathological changes in human cerebral infarction. Using this model, therapeutic effects and mechanisms of UOBT on brain ischemic injury were invetigated in rabbits following the photochemical infarcnon The results showed that UOBT could significantly reduce the mtarcted size, and improve the cerebral blood flow compared with the control animals treated with non-u-radiated ad non-oxygenated blood transfusion. These data suggest that the UOBT may have a therapeutic potential for clinical rehabilitation effect in stroke treatment

  1. Evaluation of tissue oxygen measurements for flap monitoring in an animal model

    DEFF Research Database (Denmark)

    Bonde, Christian; Elberg, Jens; Holstein-Rathlou, N.-H.

    2008-01-01

    Tissue oxygen tension (p(ti)O(2)) measurements are common in neurosurgery but uncommon in plastic surgery. We examined this technique as a monitoring method with probe placement in the subcutaneous tissue and addressed the importance of probe placement. Myocutaneous flaps were raised in an animal...

  2. Restoration of Normal Cerebral Oxygen Consumption with Rapamycin Treatment in a Rat Model of Autism-Tuberous Sclerosis.

    Science.gov (United States)

    Chi, Oak Z; Wu, Chang-Chih; Liu, Xia; Rah, Kang H; Jacinto, Estela; Weiss, Harvey R

    2015-09-01

    Tuberous sclerosis (TSC) is associated with autism spectrum disorders and has been linked to metabolic dysfunction and unrestrained signaling of the mammalian target of rapamycin (mTOR). Inhibition of mTOR by rapamycin can mitigate some of the phenotypic abnormalities associated with TSC and autism, but whether this is due to the mTOR-related function in energy metabolism remains to be elucidated. In young Eker rats, an animal model of TSC and autism, which harbors a germ line heterozygous Tsc2 mutation, we previously reported that cerebral oxygen consumption was pronouncedly elevated. Young (4 weeks) male control Long-Evans and Eker rats were divided into control and rapamycin-treated (20 mg/kg once daily for 2 days) animals. Cerebral regional blood flow ((14)C-iodoantipyrine) and O2 consumption (cryomicrospectrophotometry) were determined in isoflurane-anesthetized rats. We found significantly increased basal O2 consumption in the cortex (8.7 ± 1.5 ml O2/min/100 g Eker vs. 2.7 ± 0.2 control), hippocampus, pons and cerebellum. Regional cerebral blood flow and cerebral O2 extractions were also elevated in all brain regions. Rapamycin had no significant effect on O2 consumption in any brain region of the control rats, but significantly reduced consumption in the cortex (4.1 ± 0.3) and all other examined regions of the Eker rats. Phosphorylation of mTOR and S6K1 was similar in the two groups and equally reduced by rapamycin. Thus, a rapamycin-sensitive, mTOR-dependent but S6K1-independent, signal led to enhanced oxidative metabolism in the Eker brain. We found decreased Akt phosphorylation in Eker but not Long-Evans rat brains, suggesting that this may be related to the increased cerebral O2 consumption in the Eker rat. Our findings suggest that rapamycin targeting of Akt to restore normal cerebral metabolism could have therapeutic potential in tuberous sclerosis and autism. PMID:26048361

  3. Cerebral hemodynamic and oxygenation changes induced by inner and heard speech: a study combining functional near-infrared spectroscopy and capnography

    Science.gov (United States)

    Scholkmann, Felix; Klein, Sabine D.; Gerber, Ursina; Wolf, Martin; Wolf, Ursula

    2014-01-01

    The aim of this study was to investigate the effects of inner and heard speech on cerebral hemodynamics and oxygenation in the anterior prefrontal cortex (PFC) using functional near-infrared spectroscopy and to test whether potential effects were caused by alterations in the arterial carbon dioxide pressure (PaCO2). Twenty-nine healthy adult volunteers performed six different tasks of inner and heard speech according to a randomized crossover design. During the tasks, we generally found a decrease in PaCO (only for inner speech), tissue oxygen saturation (StO), oxyhemoglobin ([O2Hb]), total hemoglobin ([tHb]) concentration and an increase in deoxyhemoglobin concentration ([HHb]). Furthermore, we found significant relations between changes in [OHb], [HHb], [tHb], or StO and the participants' age, the baseline PETCO2, or certain speech tasks. We conclude that changes in breathing during the tasks led to lower PaCO (hypocapnia) for inner speech. During heard speech, no significant changes in PaCO occurred, but the decreases in StO, [OHb], and [tHb] suggest that changes in PaCO were also involved here. Different verse types (hexameter and alliteration) led to different changes in [tHb], implying different brain activations. In conclusion, StO, [OHb], [HHb], and [tHb] are affected by interplay of both PaCO reactivity and functional brain activity.

  4. Tissue at risk in the deep middle cerebral artery territory is critical to stroke outcome

    Energy Technology Data Exchange (ETDEWEB)

    Rosso, Charlotte; Samson, Yves [Pitie-Salpetriere Hospital, AP-HP, Urgences Cerebro-Vasculaires, Paris (France); UPMC, Univ Paris 06, Paris (France); Centre de Recherche de l' Institut du Cerveau et de la Moelle epiniere, ICM, UPMC Paris 6, Inserm, U975, CNRS, UMR 7225, COGIMAGE, Paris (France); Colliot, Olivier [UPMC, Univ Paris 06, Paris (France); Centre de Recherche de l' Institut du Cerveau et de la Moelle epiniere, ICM, UPMC Paris 6, Inserm, U975, CNRS, UMR 7225, COGIMAGE, Paris (France); Valabregue, Romain [UPMC, Univ Paris 06, Paris (France); Centre de Recherche de l' Institut du Cerveau et de la Moelle epiniere, ICM, UPMC Paris 6, Inserm, U975, CNRS, UMR 7225, Centre for NeuroImaging Research (CENIR), Paris (France); Crozier, Sophie [Pitie-Salpetriere Hospital, AP-HP, Urgences Cerebro-Vasculaires, Paris (France); Dormont, Didier [UPMC, Univ Paris 06, Paris (France); Centre de Recherche de l' Institut du Cerveau et de la Moelle epiniere, ICM, UPMC Paris 6, Inserm, U975, CNRS, UMR 7225, COGIMAGE, Paris (France); Pitie-Salpetriere Hospital, AP-HP, Department of Neuroradiology, Paris (France); Lehericy, Stephane [UPMC, Univ Paris 06, Paris (France); Centre de Recherche de l' Institut du Cerveau et de la Moelle epiniere, ICM, UPMC Paris 6, Inserm, U975, CNRS, UMR 7225, Centre for NeuroImaging Research (CENIR), Paris (France); Pitie-Salpetriere Hospital, AP-HP, Department of Neuroradiology, Paris (France)

    2011-10-15

    The clinical efficacy of thrombolysis in stroke patients is explained by the increased rate of recanalization, which limits infarct growth. However, the efficacy could also be explained by the protection of specific sites of the brain. Here, we investigate where is this outcome-related tissue at risk using voxel-based analysis. We included 68 acute stroke patients with middle cerebral artery (MCA) occlusion on the admission MRI performed within 6 h of symptoms onset (H6) and 16 controls. MCA recanalization was assessed using the magnetic resonance angiography performed at day 1 (D1). Apparent diffusion coefficient (ADC) changes were analyzed using a voxel-based method between patients vs. controls group at admission (H6) in non-recanalized vs. recanalized and in 3-month poor vs. good outcome patients at D1. Complete or partial MCA recanalization was observed in 52 of 68 patients. Good outcome at 3 months occurred in 40 patients (59%). In non-recanalized patients, ADC was decreased in the deep MCA and watershed arterial territory (the lenticular nucleus, internal capsule, and the overlying periventricular white matter). This decrease was not observed in recanalized patients at D1 or patients at H6. Fiber tracking suggested that the area is crossed by the cortico-spinal, cerebellar, and intra-hemispheric association tracts. Finally, this area almost co-localized with the area associated with poor outcome. A clinically relevant area of tissue at risk may occur in patients with MCA infarcts at the level of deep white matter fiber tracts. These findings suggest that neuroprotection research should be refocused on white matter. (orig.)

  5. Monitoring tissue oxygen availability with near infrared spectroscopy (NIRS) in health and disease

    DEFF Research Database (Denmark)

    Boushel, R; Langberg, Henning; Olesen, J; Gonzales-Alonzo, J; Bülow, J; Kjaer, M

    2001-01-01

    vessels (arterioles, capillaries and venules). Refinement of NIRS hardware and the algorithms used to deconvolute the light absorption signal have improved the resolution and validity of cytochrome oxidase measurements. NIRS has been applied to measure oxygenation in a variety of tissues including muscle...... along with the assessment of tissue O2 saturation. The venular O2 saturation can be estimated with NIRS by applying venous occlusion and measuring changes in oxygenated vs. total hemoglobin. These various measurements provide the opportunity to evaluate several important metabolic and circulatory......Near infrared spectroscopy (NIRS) is becoming a widely used research instrument to measure tissue oxygen (O2) status non-invasively. Continuous-wave spectrometers are the most commonly used devices, which provide semi-quantitative changes in oxygenated and deoxygenated hemoglobin in small blood...

  6. Contribution of oxygen-sensitive neurons of the rostral ventrolateral medulla to hypoxic cerebral vasodilatation in the rat

    Science.gov (United States)

    Golanov, E. V.; Reis, D. J.

    1996-01-01

    1. We sought to determine whether hypoxic stimulation of neurons of the rostral ventrolateral reticular nucleus (RVL) would elevate regional cerebral blood flow (rCBF) in anaesthetized paralysed rats. 2. Microinjection of sodium cyanide (NaCN; 150-450 pmol) into the RVL rapidly (within 1-2 s), transiently, dose-dependently and site-specifically elevated rCBF1 measured by laser Doppler flowmetry, by 61.3 +/- 22.1% (P anaesthesia. 4. Electrical stimulation of NaCN-sensitive sites in the RVL in spinalized rats increased rCBF measured autoradiographically with 14C iodoantipyrine (Kety method) in the mid-line thalamus (by 182.3 +/- 17.2%; P < 0.05) and cerebral cortex (by 172.6 +/- 15.6%; P < 0.05) regions, respectively, directly or indirectly innervated by RVL neurons, and in the remainder of the brain. In contrast regional cerebral glucose utilization (rCGU), measured autoradiographically with 14C-2-deoxyglucose (Sokoloff method), was increased in proportion to rCBF in the mid-line thalamus (165.6 +/- 17.8%, P < 0.05) but was unchanged in the cortex. 5. Bilateral electrolytic lesions of NaCN sensitive sites of RVL, while not altering resting rCBF or the elevation elicited by hypercarbia (arterial CO2 pressure, Pa,CO2, approximately 69 mmHg), reduced the vasodilatation elicited by normocapnic hypoxaemia (arterial O2 pressure, Pa,O2, approximately 27 mmHg) by 67% (P < 0.01) and flattened the slope of the Pa,O2-rCBF response curve. 6. We conclude that the elevation of rCBF produced in the cerebral cortex by hypoxaemia is in large measure neurogenic, mediated trans-synaptically over intrinsic neuronal pathways, and initiated by excitation of oxygen sensitive neurons in the RVL.

  7. Combined effect of protein and oxygen on reactive oxygen and nitrogen species in the plasma treatment of tissue

    Science.gov (United States)

    Gaur, Nishtha; Szili, Endre J.; Oh, Jun-Seok; Hong, Sung-Ha; Michelmore, Andrew; Graves, David B.; Hatta, Akimitsu; Short, Robert D.

    2015-09-01

    The influence of protein and molecular, ground state oxygen (O2) on the plasma generation, and transport of reactive oxygen and nitrogen species (RONS) in tissue are investigated. A tissue target, comprising a 1 mm thick gelatin film (a surrogate for real tissue), is placed on top of a 96-well plate; each well is filled with phosphate buffered saline (PBS, pH 7.4) containing one fluorescent or colorimetric reporter that is specific for one of three RONS (i.e., H2O2, NO2-, or OH•) or a broad spectrum reactive oxygen species reporter (2,7-dichlorodihydrofluorescein). A helium cold atmospheric plasma (CAP) jet contacts the top of the gelatin surface, and the concentrations of RONS generated in PBS are measured on a microplate reader. The data show that H2O2, NO2-, or OH• are generated in PBS underneath the target. Independently, measurements are made of the O2 concentration in the PBS with and without the gelatin target. Adding bovine serum albumin protein to the PBS or gelatin shows that protein either raises or inhibits RONS depending upon the O2 concentration. Our results are discussed in the context of plasma-soft tissue interactions that are important in the development of CAP technology for medicine, biology, and food manufacturing.

  8. 高压氧对急性脑梗死临床应用分析%CLINICAL APPLICATION OF HYPERBARIC OXYGENATION TO ACUTE CEREBRAL INFARCTION

    Institute of Scientific and Technical Information of China (English)

    邵伟波

    2002-01-01

    Objective:To determine the effect of hyperbaric oxygenation(HBO) on treating acute cerebral infarction(ACI). Methods: We randomly divided 60 patients with acute cerebral infarction into the treatment group and the control group. Hyperbaric oxygenation treatment was applied in the treatment group as routine drug therapy was used. The neurological function, living ability, clinical therapeutic effectiveness and hemorrheology changes of pa tients in the two groups before and after treatment were observed and evaluated. Results: The indexes of treatment were obviously improved one month after treatment (P < 0.05 ). Clinical effective rate was 93.3 % in this group,which was obviously higher than that of the control group(P < 0.05). Conclusion: Hyperbaric oxygenation can accelerate the recovery of neurological function of patients with acute cerebral infarction.

  9. Effects of Acute Bleeding Followed by Hydroxyethyl Starch 130/0.4 or a Crystalloid on Propofol Concentrations, Cerebral Oxygenation, and Electroencephalographic and Haemodynamic Variables in Pigs

    Directory of Open Access Journals (Sweden)

    Aura Silva

    2014-01-01

    Full Text Available Bleeding changes the haemodynamics, compromising organ perfusion. In this study, the effects of bleeding followed by replacement with hydroxyethyl starch 130/0.4 (HES or lactated Ringer’s (LR on cerebral oxygenation and electroencephalogram-derived parameters were investigated. Twelve young pigs under propofol-remifentanil anaesthesia were bled 30 mL/kg and, after a 20-minute waiting period, volume replacement was performed with HES (GHES; N=6 or LR (GRL; N=6. Bleeding caused a decrease of more than 50% in mean arterial pressure (P<0.01 and a decrease in cerebral oximetry (P=0.039, bispectral index, and electroencephalogram total power (P=0.04 and P<0.01, resp., while propofol plasma concentrations increased (P<0.01. Both solutions restored the haemodynamics and cerebral oxygenation similarly and were accompanied by an increase in electroencephalogram total power. No differences between groups were found. However, one hour after the end of the volume replacement, the cardiac output (P=0.03 and the cerebral oxygenation (P=0.008 decreased in the GLR and were significantly lower than in GHES (P=0.02. Volume replacement with HES 130/0.4 was capable of maintaining the cardiac output and cerebral oxygenation during a longer period than LR and caused a decrease in the propofol plasma concentrations.

  10. 99mTc-ECD brain perfusion SPECT imaging for the assessment of brain perfusion in cerebral palsy (CP) patients with evaluation of the effect of hyperbaric oxygen therapy

    OpenAIRE

    Asl, Mina Taghizadeh; Yousefi, Farzaneh; Nemati, Reza; Assadi, Majid

    2015-01-01

    Objective: The present study was carried out to evaluate cerebral perfusion in different types of cerebral palsy (CP) patients. For those patients who underwent hyperbaric oxygen therapy, brain perfusion before and after the therapy was compared. Methods: A total of 11 CP patients were enrolled in this study, of which 4 patients underwent oxygen therapy. Before oxygen therapy and at the end of 40 sessions of oxygen treatment, 99mTc-ECD brain perfusion single photon emission computed tomograph...

  11. Development of 200-channel mapping system for tissue oxygenation measured by near-infrared spectroscopy

    Science.gov (United States)

    Niwayama, Masatsugu; Kohata, Daisuke; Shao, Jun; Kudo, Nobuki; Hamaoka, Takatumi; Katsumura, Toshihito; Yamamoto, Katsuyuki

    2000-07-01

    Near-infrared spectroscopy (NIRS) is a very useful technique for noninvasive measurement of tissue oxygenation. Among various methods of NIRS, continuous wave near-infrared spectroscopy (CW- NIRS) is especially suitable for real-time measurement and for practical use. CW-NIRS has recently been applied in vivo reflectance imaging of muscle oxygenation and brain activity. However, conventional mapping systems do not have a sufficient mapping area at present. Moreover, they do not enable quantitative measurement of tissue oxygenation because conventional NIRS is based on the inappropriate assumption that tissue is homogeneous. In this study, we developed a 200-channel mapping system that enables measurement of changes in oxygenation and blood volume and that covers a wider area (30 cm x 20 cm) than do conventional systems. The spatial resolution (source- detector separation) of this system is 15 mm. As for the effcts of tissue inhomogeneity on muscle oxygenation measurement, subcutaneous adipose tissue greatly reduces measurement sensitivity. Therefore, we also used a correction method for influence of the subcutaneous fat layer so that we could obtain quantitative changes in concentrations of oxy- and deoxy- hemoglobin. We conducted exercise tests and measured the changed in hemoglobin concentration in the thigh using the new system. The working muscles in the exercises could be imaged, and the heterogeneity of the muscles was shown. These results demonstrated the new 200-channel mapping system enables observation of the distribution of muscle metabolism and localization of muscle function.

  12. Propagation of damage in brain tissue: coupling the mechanics of oedema and oxygen delivery.

    Science.gov (United States)

    Lang, Georgina E; Vella, Dominic; Waters, Sarah L; Goriely, Alain

    2015-11-01

    Brain tissue swelling, or oedema, is a dangerous consequence of traumatic brain injury and stroke. In particular, a locally swollen region can cause the injury to propagate further through the brain: swelling causes mechanical compression of the vasculature in the surrounding tissue and so can cut off that tissue's oxygen supply. We use a triphasic mathematical model to investigate this propagation, and couple tissue mechanics with oxygen delivery. Starting from a fully coupled, finite elasticity, model, we show that simplifications can be made that allow us to express the volume of the propagating region of damage analytically in terms of key parameters. Our results show that performing a craniectomy, to alleviate pressure in the brain and allow the tissue to swell outwards, reduces the propagation of damage; this finding agrees with experimental observations. PMID:25822263

  13. Role of ammonia, inflammation, and cerebral oxygenation in brain dysfunction of acute-on-chronic liver failure patients.

    Science.gov (United States)

    Sawhney, Rohit; Holland-Fischer, Peter; Rosselli, Matteo; Mookerjee, Rajeshwar P; Agarwal, Banwari; Jalan, Rajiv

    2016-06-01

    Hepatic encephalopathy (HE) is a common feature of acute-on-chronic liver failure (ACLF). Although ammonia, inflammation, and cerebral oxygenation are associated with HE in acute liver failure, their roles in ACLF are unknown. The aim of this prospective, longitudinal study was to determine the role of these pathophysiological variables in ACLF patients with and without HE. We studied 101 patients with ACLF admitted to the intensive care unit. Severity of ACLF and HE, arterial ammonia, jugular venous oxygen saturation (JVO2 ), white blood cell count (WCC), and C-reactive protein were measured at days 0, 1, 3, and 7. Patients were followed until death or hospital discharge. Mortality was high (51 patients, 50.5%), especially in patients with HE of whom 35 of 53 (66.0%) died regardless of ACLF severity. At baseline, increased WCC and abnormal JVO2 (high or low) were independent predictors of death. Further deterioration in inflammation, JVO2 , and ammonia were also predictive of mortality. JVO2 deviation and hyperammonemia were associated with the presence and severity of HE; improvement in these parameters was associated with a reduction in HE grade. No direct interaction was observed between these variables in regards to mortality or HE. In conclusion, this study describes potential mechanisms of HE in ACLF indicating that ammonia and abnormal cerebral oxygenation are important. The results suggest that ammonia, JVO2 , and WCC are important prognostic biomarkers and therapeutic targets. The relative roles of these pathophysiological factors in the pathogenesis of HE in ACLF or guiding therapy to improve survival requires future study. Liver Transplantation 22 732-742 2016 AASLD. PMID:27028317

  14. Increased oxygenation of the cerebral prefrontal cortex prior to the onset of voluntary exercise in humans.

    Science.gov (United States)

    Matsukawa, Kanji; Ishii, Kei; Liang, Nan; Endo, Kana; Ohtani, Ryo; Nakamoto, Tomoko; Wakasugi, Rie; Kadowaki, Akito; Komine, Hidehiko

    2015-09-01

    To determine whether output from the forebrain (termed central command) may descend early enough to increase cardiac and renal sympathetic outflows at the onset of voluntary exercise, we examined the changes in regional tissue blood flows of bilateral prefrontal cortices with near-infrared spectroscopy, precisely identifying the onset of voluntary ergometer 30-s exercise at 41 ± 2% of the maximal exercise intensity in humans. Prefrontal oxygenated-hemoglobin (Oxy-Hb) concentration was measured as index of regional blood flow unless deoxygenated-hemoglobin concentration remained unchanged. Prefrontal Oxy-Hb concentration increased significantly (P start, whereas such increase in prefrontal Oxy-Hb was absent before exercise abruptly started by a verbal cue. Furthermore, the increase in prefrontal Oxy-Hb observed at the initial 15-s period of exercise was greater with arbitrary start than cued start. The prefrontal Oxy-Hb, thereafter, decreased during the later period of exercise, irrespective of either arbitrary or cued start. The reduction in prefrontal Oxy-Hb had the same time course and response magnitude as that during motor-driven passive exercise. Cardiac output increased at the initial period of exercise, whereas arterial blood pressure and total peripheral resistance decreased. The depressor response was more pronounced (P start than cued start. Taken together, it is suggested that the increase in prefrontal Oxy-Hb observed prior to the onset of voluntary exercise may be in association with central command, while the later decrease in the Oxy-Hb during exercise may be in association with feedback stimulated by mechanical limb motion. PMID:26183481

  15. 'Multi-associations': predisposed to misinterpretation of peripheral tissue oxygenation and circulation in neonates

    International Nuclear Information System (INIS)

    Interpretation of peripheral circulation in ill neonates is crucial but difficult. The aim was to analyse parameters potentially influencing peripheral oxygenation and circulation. In a prospective observational cohort study in 116 cardio-circulatory stable neonates, peripheral muscle near-infrared spectroscopy (NIRS) with venous occlusion was performed. Tissue oxygenation index (TOI), mixed venous oxygenation (SvO2), fractional oxygen extraction (FOE), fractional tissue oxygen extraction (FTOE), haemoglobin flow (Hbflow), oxygen delivery (DO2), oxygen consumption (VO2), and vascular resistance (VR) were assessed. Correlation coefficients between NIRS parameters and demographic parameters (gestational age, birth weight, age, actual weight, diameter of calf, subcutaneous adipose tissue), monitoring parameters (heart rate, arterial oxygen saturation (SaO2), mean blood pressure (MAP), core/peripheral temperature, central/peripheral capillary refill time) and laboratory parameters (haemoglobin concentration (Hb-blood), pCO2) were calculated. All demographic parameters except for Hbflow and DO2 correlated with NIRS parameters. Heart rate correlated with TOI, SvO2, VO2 and VR. SaO2 correlated with FOE/FTOE. MAP correlated with Hbflow, DO2, VO2 and VR. Core temperature correlated with FTOE. Peripheral temperature correlated with all NIRS parameters except VO2. Hb-blood correlated with FOE and VR. pCO2 levels correlated with TOI and SvO2. The presence of multiple interdependent factors associated with peripheral oxygenation and circulation highlights the difficulty in interpreting NIRS data. Nevertheless, these findings have to be taken into account when analysing peripheral oxygenation and circulation data

  16. Effect of oxygen breathing on micro oxygen bubbles in nitrogen-depleted rat adipose tissue at sea level and 25 kPa altitude exposures

    DEFF Research Database (Denmark)

    Randsoe, Thomas; Hyldegaard, Ole

    2012-01-01

    The standard treatment of altitude decompression sickness (aDCS) caused by nitrogen bubble formation is oxygen breathing and recompression. However, micro air bubbles (containing 79% nitrogen), injected into adipose tissue, grow and stabilize at 25 kPa regardless of continued oxygen breathing...... at 101.3 kPa (sea level) or at 25 kPa altitude exposures during continued oxygen breathing. In keeping with previous observations and bubble kinetic models, we hypothesize that oxygen breathing may contribute to oxygen bubble growth at altitude. Anesthetized rats were exposed to 3 h of oxygen...... prebreathing at 101.3 kPa (sea level). Micro oxygen bubbles of 500-800 nl were then injected into the exposed abdominal adipose tissue. The oxygen bubbles were studied for up to 3.5 h during continued oxygen breathing at either 101.3 or 25 kPa ambient pressures. At 101.3 kPa, all bubbles shrank consistently...

  17. Dependency of the [18f]fluoro misonidazole uptake on oxygen delivery and tissue oxygenation in the porcine liver

    International Nuclear Information System (INIS)

    We have previously shown that the accumulation of fluorine-18-labeled fluoromisonidazole ([18F]FMISO) is inversely correlated to tissue oxygenation, allowing the quantification of porcine liver tissue hypoxia in vivo. We determined the activity from administered [18F]FMISO in relation to the hepatic oxygen availability and the partial pressure of oxygen in tissue (tPO2) to define a critical oxygen delivery on a regional basis. [18F]FMISO was injected 2 h after onset of regional liver hypoxia due to arterial occlusion of branches of the hepatic artery in 10 domestic pigs. During the experimental procedure the fractional concentration of inspired oxygen (FiO2) was set to 0.67 in group A ( N=5) and to 0.21 in group B ( N=5) animals. Immediately before sacrifice, the tPO2 was determined in normal flow and flow-impaired liver segments. The standardized uptake values (SUV) for [18F]FMISO was calculated from 659 single tissue samples obtained 3 h after injection of approximately 10 MBq/kg body weight [18F]FMISO and was compared with the regional total hepatic oxygen delivery (DO2) calculated from the regional arterial and portal venous flow (based on 141Ce- and 99mTc-microspheres measurements) and the oxygen content of the arterial and portal venous blood. In 121 tPO2-measured liver tissue samples, the mean DO2 was significantly decreased in occluded liver tissue samples [group A: 0.063 (0.044-0.089); group B: 0.046 (0.032-0.066)] compared to normal flow segments [group A: 0.177 (0.124-0.252); group B: 0.179 (0.128-0.25) mL·min-1·g-1; geometric mean (95% confidence limits); p2 of occluded segments [group A: 5.1 (3.2-8.1); group B: 3.9 (2.4-6.2) mm Hg] was significantly decreased compared to normal flow segments [group A: 20.2 (12.6-32.5); group B: 22.4 (14.3-35.2) mm Hg; p 18F]FMISO administration, the mean [18F]FMISO SUV determined in tPO2-measured occluded segments was significantly higher [group A: 4.08 (3.12-5.34), group B: 5.43 (4.14-7.13)] compared to normal liver

  18. Elevated global cerebral blood flow, oxygen extraction fraction and unchanged metabolic rate of oxygen in young adults with end-stage renal disease: an MRI study

    International Nuclear Information System (INIS)

    To noninvasively assess global cerebral blood flow (CBF), oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO2) in young adults with end-stage renal disease (ESRD). Thirty-six patients and 38 healthy volunteers were included and took part in MR examinations, blood and neuropsychological tests. CBF and OEF were measured by phase-contrast and T2-relaxation-under-spin-tagging MRI techniques, respectively. CMRO2 was computed from CBF, OEF and hematocrit according to Fick's principle. Correlations were performed between MR measurements, blood biochemistry measurements and neuropsychological test scores. Compared with controls, ESRD patients had elevated CBF (72.9 ± 12.5 vs. 63.8 ± 8.5 ml min-1 100 g-1, P < 0.001), elevated OEF (47.2 ± 10.2 vs. 35.8 ± 5.4 %, P < 0.001), but unaffected CMRO2 (199.5 ± 36.4 vs. 193.8 ± 28.6 μmol O2 min-1 100 g-1, P = 0.879). Hematocrit negatively correlated with CBF (r = -0.640, P < 0.001) and OEF (r = -0.701, P < 0.001), but not with CMRO2. Altered neuropsychological test scores of ESRD patients were associated with OEF and CBF, but not with CMRO2. There were weak relationships between eGFR and hematocrit (r = 0.308, P = 0.068) or CBF (r = 0.318, P = 0.059). Our findings suggested that anaemic young adults with ESRD may afford higher CBF and OEF to maintain a normal CMRO2. Despite this compensatory process, however, cognitive function was still impaired and its severity was correlated with their CBF and OEF abnormality. (orig.)

  19. Elevated global cerebral blood flow, oxygen extraction fraction and unchanged metabolic rate of oxygen in young adults with end-stage renal disease: an MRI study

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Gang; Lou, Yaxian; Pan, Zhiying; Liu, Ya [Medical School of Nanjing University, Department of Medical Imaging, Jinling Hospital, Nanjing, Jiangsu (China); Nanjing University of Aeronautics and Astronautics, College of Aivil Aviation, Nanjing, Jiangsu (China); Wen, Jiqiu; Li, Xue; Zhang, Zhe [Medical School of Nanjing University, National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing, Jiangsu (China); Lu, Hanzhang [University of Texas Southwestern Medical Center, Advanced Imaging Research Center, Dallas, TX (United States); Liu, Wei [Siemens Shenzhen Magnetic Resonance Ltd., Shenzhen, Guangdong (China); Liu, Hui [Siemens MR NEA Collaboration, Siemens Ltd., Shanghai (China); Chen, Huijuan; Kong, Xiang; Luo, Song; Jiang, Xiaolu; Zhang, Zongjun; Zhang, Long Jiang; Lu, Guang Ming [Medical School of Nanjing University, Department of Medical Imaging, Jinling Hospital, Nanjing, Jiangsu (China)

    2016-06-15

    To noninvasively assess global cerebral blood flow (CBF), oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO{sub 2}) in young adults with end-stage renal disease (ESRD). Thirty-six patients and 38 healthy volunteers were included and took part in MR examinations, blood and neuropsychological tests. CBF and OEF were measured by phase-contrast and T2-relaxation-under-spin-tagging MRI techniques, respectively. CMRO{sub 2} was computed from CBF, OEF and hematocrit according to Fick's principle. Correlations were performed between MR measurements, blood biochemistry measurements and neuropsychological test scores. Compared with controls, ESRD patients had elevated CBF (72.9 ± 12.5 vs. 63.8 ± 8.5 ml min{sup -1} 100 g{sup -1}, P < 0.001), elevated OEF (47.2 ± 10.2 vs. 35.8 ± 5.4 %, P < 0.001), but unaffected CMRO{sub 2} (199.5 ± 36.4 vs. 193.8 ± 28.6 μmol O{sub 2} min{sup -1} 100 g{sup -1}, P = 0.879). Hematocrit negatively correlated with CBF (r = -0.640, P < 0.001) and OEF (r = -0.701, P < 0.001), but not with CMRO{sub 2}. Altered neuropsychological test scores of ESRD patients were associated with OEF and CBF, but not with CMRO{sub 2}. There were weak relationships between eGFR and hematocrit (r = 0.308, P = 0.068) or CBF (r = 0.318, P = 0.059). Our findings suggested that anaemic young adults with ESRD may afford higher CBF and OEF to maintain a normal CMRO{sub 2}. Despite this compensatory process, however, cognitive function was still impaired and its severity was correlated with their CBF and OEF abnormality. (orig.)

  20. Multimodal optical imaging system for in vivo investigation of cerebral oxygen delivery and energy metabolism

    OpenAIRE

    Yaseen, Mohammad A.; Vivek J Srinivasan; Gorczynska, Iwona; Fujimoto, James G.; Boas, David A.; Sakadžić, Sava

    2015-01-01

    Improving our understanding of brain function requires novel tools to observe multiple physiological parameters with high resolution in vivo. We have developed a multimodal imaging system for investigating multiple facets of cerebral blood flow and metabolism in small animals. The system was custom designed and features multiple optical imaging capabilities, including 2-photon and confocal lifetime microscopy, optical coherence tomography, laser speckle imaging, and optical intrinsic signal i...

  1. Contrast Enhancement for in vivo Visible Reflectance Imaging of Tissue Oxygenation

    OpenAIRE

    Crane, Nicole J.; Schultz, Zachary D.; Levin, Ira W.

    2007-01-01

    Results are presented illustrating a straightforward algorithm to be used for real time monitoring of oxygenation levels in blood cells and tissue based on the visible spectrum of hemoglobin. Absorbance images obtained from the visible reflection of white light through separate red and blue bandpass filters recorded by monochrome CCDs are combined to create enhanced images that suggest a quantitative correlation to the degree of oxygenated and deoxygenated hemoglobin in red blood cells. The f...

  2. Influence of residual oxygen-15-labeled carbon monoxide radioactivity on cerebral blood flow and oxygen extraction fraction in a dual-tracer autoradiographic method

    International Nuclear Information System (INIS)

    Cerebral blood flow (CBF), cerebral metabolic rate of oxygen (CMRO2), oxygen extraction fraction (OEF), and cerebral blood volume (CBV) are quantitatively measured with positron emission tomography (PET) with 15O gases. Kudomi et al. developed a dual tracer autoradiographic (DARG) protocol that enables the duration of a PET study to be shortened by sequentially administrating 15O2 and C15O2 gases. In this protocol, before the sequential PET scan with 15O2 and C15O2 gases (15O2-C15O2 PET scan), a PET scan with C15O should be preceded to obtain CBV image. C15O has a high affinity for red blood cells and a very slow washout rate, and residual radioactivity from C15O might exist during a 15O2-C15O2 PET scan. As the current DARG method assumes no residual C15O radioactivity before scanning, we performed computer simulations to evaluate the influence of the residual C15O radioactivity on the accuracy of measured CBF and OEF values with DARG method and also proposed a subtraction technique to minimize the error due to the residual C15O radioactivity. In the simulation, normal and ischemic conditions were considered. The 15O2 and C15O2 PET count curves with the residual C15O PET counts were generated by the arterial input function with the residual C15O radioactivity. The amounts of residual C15O radioactivity were varied by changing the interval between the C15O PET scan and 15O2-C15O2 PET scan, and the absolute inhaled radioactivity of the C15O gas. Using the simulated input functions and the PET counts, the CBF and OEF were computed by the DARG method. Furthermore, we evaluated a subtraction method that subtracts the influence of the C15O gas in the input function and PET counts. Our simulations revealed that the CBF and OEF values were underestimated by the residual C15O radioactivity. The magnitude of this underestimation depended on the amount of C15O radioactivity and the physiological conditions. This underestimation was corrected by the subtraction method. This

  3. Carbogen inhalation increases oxygen transport to hypoperfused brain tissue in patients with occlusive carotid artery disease: increased oxygen transport to hypoperfused brain

    DEFF Research Database (Denmark)

    Ashkanian, Mahmoud; Gjedde, Albert; Mouridsen, Kim;

    2009-01-01

    Sa(O2) are readily obtained with carbogen, while oxygen increases only Sa(O2). Thus, carbogen improves oxygen transport to brain tissue more efficiently than oxygen alone. Further studies with more subjects are, however, needed to investigate the applicability of carbogen for long-term inhalation and...

  4. An irradiation system for photodynamic therapy with a fiber-optic sensor for measuring tissue oxygen

    Science.gov (United States)

    Quintanar, L.; Fabila, D.; Stolik, S.; de la Rosa, J. M.

    2013-11-01

    Photodynamic Therapy is a well known treatment based on the interaction of light of specific wavelength with a photosensitizing drug. In the presence of oxygen molecules, the illumination of the photosensitizer can activate the production of reactive oxygen species, which leads to the death of target cells within the treated tissue. In order to obtain the best therapy response, the tissue oxygen concentration should be measured to adjust the therapy parameters before and during the treatment. In this work, an irradiation system for 5-Aminolevulinic Acid Photodynamic Therapy is presented. It allows the application of visible light radiation of 630 nm using as a light source a high-brightness light emitting diode with an optical-power automatic control considering a light depth-distribution model. A module to measure the tissue oxygen saturation has been implemented into the system. It is based on two light emitting diodes of 660 nm and 940 nm as light sources, a photodiode as a detector and a new handheld fiber optic reflectance pulse oximetry sensor for estimating the blood oxygen saturation within the tissue. The pulse oximetry sensor was modeled through multilayered Monte Carlo simulations to study the behavior of the sensor with changes in skin thickness and melanin content.

  5. The effects of anticholinergic drugs on regional cerebral blood flow, and oxygen metabolism in previously untreated patients with Parkinson's disease

    International Nuclear Information System (INIS)

    Regional cerebral blood flow (rCBF) and oxygen metabolism (rCMRO2) were measured using the steady-state 15O technique and positron emission tomography (PET) in six previously untreated patients with Parkinson's disease before and after trihexyphenidyl (THP) treatment. The patients comprised of 4 men and 2 women with Hoehn-Yahr stage II-III. Their ages at the onset of the study ranged from 46 to 57 years (mean±SD, 51.8±3.7) and the duration of the illness ranged from 10 to 48 months (mean±SD, 28.8±15.5). The PET study, assessments of the disability and cognitive function were undergone twice. The first time assessments were done was when the patients were not receiving any drugs, and the second time was one to three months after administration of 6 mg THP. All patients showed clinical improvement after THP treatment. The mean disability score of Unified Parkinson's Disease Rating Scale decreased from 35.1 (SD±11.3) to 25.7 (SD±11.6). The cognitive function assessed by Hasegawa's dementia rating scale-revised, Mini-Mental State Examination, Wechsler Adult Intelligence Scale-Revised, and Wechsler Memory Scale-Revised, were not significantly different before and after the THP treatment. After the THP treatment, rCBF and rCMRO2 decreased significantly in the striatum (about 15%) and all cerebral cortices (about 10%) on both sides contralateral and ipsilateral to the predominantly symptomatic limbs. We conclude that an anticholinergic THP decreases the rCBF and rCMRO2 significantly in the cerebral cortices without cognitive impairment in early untreated patients with Parkinson's disease. (author)

  6. 脑血管周围组织通道的功能%Functions of cerebral perivascular tissue channel

    Institute of Scientific and Technical Information of China (English)

    王俊华; 田牛; 郑世荣; 刘育英; 刘凤英; 李玉珍; 刘秀华; 赵秀梅; 韩岳; 蔡莉蓉

    2005-01-01

    背景:在缺乏淋巴管的脑组织内,脑组织液与脑脊液间、脑组织液与淋巴系统间以及各部位脑实质之间的物质传递的过程与途径是一个被忽略的未知领域,这就是本文要探讨的脑组织通道,对指导中枢神经系统疾病的预后与康复干预具有重要意义.目的:探讨脑血管周围组织通道的功能,为研究脑组织的病理生理机制提供理论依据.设计:完全随机对照实验研究.单位:解放军空军总医院心内科;解放军总医院病理生理研究室.材料:实验在解放军总医院病理生理研究室完成.选择雄性SD大鼠20只,体质量250~300 g,购自解放军总医院动物中心.干预:将大相对分子质量的异硫氰酸荧光素标记的白蛋白(fluorescein isothiocyanate labelled albumin,FA)及相对分子质量较小的异硫氰酸荧光素标记的右旋糖酐(fluorescein isothiocyanate labelled dextran,FD)分别定位注射入大鼠脑内,一定时间后通过示踪剂与血管同时显影的方法观察注入的荧光物质在脑内的分布情况及其与组织结构间的关系.主要观察指标:荧光显微镜下观察注入的荧光示踪剂在脑内的分布情况、与血管之间的关系;对比分析注射不同相对分子质量荧光示踪剂实验组之间示踪剂分布的差异.结果:注入FA,FD之后均可见微血管周围广泛分布荧光浓集细胞(Mato细胞);FD在脑内扩散速度大于FA;FA注入后还出现血管周围荧光浓集影像,并沿血管通向远处,在皮质者通向脑表面,在白质者通向脑腹侧颅底血管,速度与距离均大于简单扩散.结论:脑血管周围组织通道与细胞间组织通道相比,具有物质传递优势;具有与淋巴管类似的功能,在大分子物质的传递引流方面具有重要作用;它与Mato细胞共同参与脑内免疫.%BACKGROUND: The substance transmitting process and pathway in cerebral tissues in which there are lack of lymphatic vessels, between cerebral

  7. Monitoring tissue oxygen availability with near infrared spectroscopy (NIRS) in health and disease

    DEFF Research Database (Denmark)

    Boushel, Robert Christopher; Langberg, H; Olesen, J;

    2001-01-01

    Near infrared spectroscopy (NIRS) is becoming a widely used research instrument to measure tissue oxygen (O2) status non-invasively. Continuous-wave spectrometers are the most commonly used devices, which provide semi-quantitative changes in oxygenated and deoxygenated hemoglobin in small blood......, brain and connective tissue, and more recently it has been used in the clinical setting to assess circulatory and metabolic abnormalities. Quantitative measures of blood flow are also possible using NIRS and a light-absorbing tracer, which can be applied to evaluate circulatory responses to exercise...

  8. CEREBRAL SINUS THROMBOSIS IN A CASE OF ANTI-PHOSPHOLIPID ANTIBODY SYNDROME WITHOUT ASSOCIATED CONNECTIVE TISSUE INVOLVEMENT

    Directory of Open Access Journals (Sweden)

    Biswarup

    2014-12-01

    Full Text Available : The association of antiphospholipid antibodies with vascular thrombotic episodes is well established. In absence of other connective tissue disease such an association is very rare & known as the primary antiphospholipid antibody syndrome. Cerebral venous sinus thrombosis is associated with hypercoaguable states and a number of immune-mediated conditions. However the report of cerebral venous sinus thrombosis with antiphospholipid antibodies alone is limited. Here a case presenting with painful bilateral ophthalmoplegia with bilateral optic disc edema (due to raised intra cranial tension showing positive lupus anticoagulant in serum and right central venous sinus (transverse and sigmoid thrombosis on MRI and MR venogram is reported which showed clinical improvement with anticoagulant therapy

  9. Massive Hemorrhage from Internal Carotid Artery Pseudoaneurysm Successfully Treated by Transcatheter Arterial Embolization with Assessment of Regional Cerebral Oxygenation

    International Nuclear Information System (INIS)

    A 54-year-old male presented with intermittent massive hemorrhage from recurrent oropharyngeal cancer. The angiogram showed the encasements at the main trunk of the left internal carotid artery (ICA) and external carotid artery (ECA). Transcatheter arterial embolization (TAE) of the ECA with gelatin sponge particles and microcoils was performed. However, hemorrhage recurred several hours after the initial TAE. The second angiogram showed a large pseudoaneurysm of the ICA developing at the encasement on the initial angiogram. As a simple neurologic test, regional cerebral oxygenation (rSO2) was assessed with and without manual compression of the common carotid artery (CCA). With compression of the left CCA, the rSO2 did not change. We therefore performed isolation of the pseudoaneurysm. We embolized proximally and distally to the ICA pseudoaneurysm with microcoils and the pseudoaneurysm disappeared. No major complications occurred and no massive hemorrhage recurred until death from the cancer. TAE was an effective treatment for massive hemorrhage caused by tumor invasion to ICA. Assessment of rSO2 was a simple and useful neurologic test predicting the cerebral blood flow to prevent complications of TAE

  10. Eigenspectra optoacoustic tomography achieves quantitative blood oxygenation imaging deep in tissues

    Science.gov (United States)

    Tzoumas, Stratis; Nunes, Antonio; Olefir, Ivan; Stangl, Stefan; Symvoulidis, Panagiotis; Glasl, Sarah; Bayer, Christine; Multhoff, Gabriele; Ntziachristos, Vasilis

    2016-06-01

    Light propagating in tissue attains a spectrum that varies with location due to wavelength-dependent fluence attenuation, an effect that causes spectral corruption. Spectral corruption has limited the quantification accuracy of optical and optoacoustic spectroscopic methods, and impeded the goal of imaging blood oxygen saturation (sO2) deep in tissues; a critical goal for the assessment of oxygenation in physiological processes and disease. Here we describe light fluence in the spectral domain and introduce eigenspectra multispectral optoacoustic tomography (eMSOT) to account for wavelength-dependent light attenuation, and estimate blood sO2 within deep tissue. We validate eMSOT in simulations, phantoms and animal measurements and spatially resolve sO2 in muscle and tumours, validating our measurements with histology data. eMSOT shows substantial sO2 accuracy enhancement over previous optoacoustic methods, potentially serving as a valuable tool for imaging tissue pathophysiology.

  11. Eigenspectra optoacoustic tomography achieves quantitative blood oxygenation imaging deep in tissues

    Science.gov (United States)

    Tzoumas, Stratis; Nunes, Antonio; Olefir, Ivan; Stangl, Stefan; Symvoulidis, Panagiotis; Glasl, Sarah; Bayer, Christine; Multhoff, Gabriele; Ntziachristos, Vasilis

    2016-01-01

    Light propagating in tissue attains a spectrum that varies with location due to wavelength-dependent fluence attenuation, an effect that causes spectral corruption. Spectral corruption has limited the quantification accuracy of optical and optoacoustic spectroscopic methods, and impeded the goal of imaging blood oxygen saturation (sO2) deep in tissues; a critical goal for the assessment of oxygenation in physiological processes and disease. Here we describe light fluence in the spectral domain and introduce eigenspectra multispectral optoacoustic tomography (eMSOT) to account for wavelength-dependent light attenuation, and estimate blood sO2 within deep tissue. We validate eMSOT in simulations, phantoms and animal measurements and spatially resolve sO2 in muscle and tumours, validating our measurements with histology data. eMSOT shows substantial sO2 accuracy enhancement over previous optoacoustic methods, potentially serving as a valuable tool for imaging tissue pathophysiology. PMID:27358000

  12. How to Get Hyperbaric Oxygen Therapy for Children with Cerebral Palsy or Brain Injury: Navigating Insurance Denials, Red Tape, and Other Challenges

    Science.gov (United States)

    Console, Richard P., Jr.

    2010-01-01

    Medical professionals who use hyperbaric oxygen therapy (HBOT) say that recent studies, as well as anecdotal evidence, indicate that this treatment significantly improves the lives of many children with cerebral palsy and other types of chronic brain injury. So why do many children with these diagnoses not have access to this treatment? Simply…

  13. Energy spectra of secondary neutrons produced by high energy bremsstrahlung in carbon, nitrogen, oxygen and tissue

    International Nuclear Information System (INIS)

    Neutron energy spectra in carbon, nitrogen and oxygen were calculated for various bremsstrahlung end-point energies and, from these, tissue spectra were calculated using the tissue equivalent molecular formula C5H40O18N. The method involves folding the known bremsstrahlung spectrum shape with the cross section for each possible decay mode in each element which leads to neutron production. The partial photoneutron cross sections used have been derived from published data

  14. Simultaneous Blood–Tissue Exchange of Oxygen, Carbon Dioxide, Bicarbonate, and Hydrogen Ion

    OpenAIRE

    Dash, Ranjan K.; BASSINGTHWAIGHTE, JAMES B.

    2006-01-01

    A detailed nonlinear four-region (red blood cell, plasma, interstitial fluid, and parenchymal cell) axially distributed convection-diffusion-permeation-reaction-binding computational model is developed to study the simultaneous transport and exchange of oxygen (O2) and carbon dioxide (CO2) in the blood–tissue exchange system of the heart. Since the pH variation in blood and tissue influences the transport and exchange of O2 and CO2 (Bohr and Haldane effects), and since most ...

  15. Cerebral Metabolic Profiling of Hypothermic Circulatory Arrest with and Without Antegrade Selective Cerebral Perfusion: Evidence from Nontargeted Tissue Metabolomics in a Rabbit Model

    Directory of Open Access Journals (Sweden)

    Li-Hua Zou

    2016-01-01

    Conclusions: The present study applied metabolomics analysis to identify the cerebral metabolic profiling in rabbits with ASCP, and the results may shed new lights that cerebral metabolism is better preserved by ASCP compared with DHCA alone.

  16. The effect of Sub-maximal exercise-rehabilitation program on cardio-respiratory endurance indexes and oxygen pulse in patients with spastic cerebral palsy

    Directory of Open Access Journals (Sweden)

    M Izadi

    2006-05-01

    Full Text Available Background: Physical or cardio-respiratory fitness are of the best important physiological variables in children with cerebral palsy (CP, but the researches on exercise response of individuals with CP are limited. Our aim was to determine the effect of sub-maximal rehabilitation program (aerobic exercise on maximal oxygen uptake, oxygen pulse and cardio- respiratory physiological variables of children with moderate to severe spastic cerebral palsy diplegia and compare with able-bodied children. Methods: In a controlled clinical trial study, 15 children with diplegia spastic cerebral palsy, were recruited on a voluntarily basis (experimental group and 18 subjects without neurological impairments selected as control group. In CP group, aerobic exercise program performed on the average of exercise intensity (144 beat per minute of heart rate, 3 times a week for 3 months. The time of each exercise session was 20-25 minutes. Dependent variables were measured in before (pretest and after (post test of rehabilitation program through Mac Master Protocol on Tantories cycle ergometer in CP group and compared with the control group. Results: The oxygen pulse (VO2/HR during ergometery protocol was significantly lower in CP group than normal group (P<0.05. No significant statistical difference in maximal oxygen uptake (VO2 max was found between groups. The rehabilitation program leads to little increase of this variable in CP group. After sub-maximal exercise in pretest and post test, the heart rate of patient group was greater than control group, and aerobic exercise leads to significant decrease in heart rate in CP patients(P<0.05. Conclusion: The patients with spastic cerebral palsy, because of high muscle tone, severe spasticity and involuntarily movements have higher energy cost and lower aerobic fitness than normal people. The rehabilitation exercise program can improve physiological function of muscle and cardio-respiratory endurance in these

  17. Regional cerebral blood flow and oxygen metabolism in patients with ischemic stroke studied with high resolution pet and the O-15 labelled gas steady-state method

    International Nuclear Information System (INIS)

    Although regional cerebral blood flow (rCBF) studies have considerably increased pathophysiological knowledge in ischemic cerebrovascular disease, sometimes the results of such studies do not correlate with neurological abnormalities observed in the subjects being examined. Because regional neuronal activities always couple to the regional energy metabolism of brain tissue, simultaneous observation of rCBF and regional energy metabolism, such as regional oxygen consumption (rCMRO/sub 2/) and regional glucose consumption (rCMRG1), will provide greater understanding of the pathophysiology of the disease than rCBF study alone. Positron emission tomography (PET) using the 0-15 labelled gas steady-state method offers simultaneous measurement of rCBF and rCMRO/sub 2/ in vivo, and demonstrates imbalance between rCBF and rCMRO/sub 2/ in an ischemic lesion in a human brain. However, clinical PET studies in ischemic cerebrovascular disease reported previously, have been carried out using low resolution (more than 15 mm in the full width at half maximum; FWHM) PET. This report presents preliminary results using a high resolution tomograph; Headtome III and 0-15 labelled gas steady state method to investigate ischemic cerebrovascular disease

  18. Detecting the subregion proceeding to infarction in hypoperfused cerebral tissue: a study with diffusion and perfusion weighted MRI.

    Science.gov (United States)

    Liu, Y; Karonen, J O; Vanninen, R L; Nuutinen, J; Perkiö, J; Vainio, P A; Soimakallio, S; Aronen, H J

    2003-06-01

    Diffusion and perfusion weighted MRI have been widely used in ischaemic stroke. We studied 17 patients in whom ischaemic areas showed an ischaemic core, an area of infarct growth and hypoperfused but ultimately surviving tissue. Apparent diffusion coefficients (ADC) were measured on days 1, 2, and 8 in the three subregions and in contralateral control areas. Cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) were measured in these regions on day 1 perfusion maps. On day 1, the ischaemic core had very low ADC and CBF and increased MTT. The ADC in the ischaemic core gradually increased during the week. The area of infarct growth on day 1 had slightly but significantly decreased ADC (96% of control, P=0.028), moderately decreased CBF and increased MTT. On day 1 the hypoperfused but surviving tissue had slightly but significantly increased ADC (103% of control, P=0.001), mildly decreased CBF and increased CBV and MTT. The ADC of the area of infarct growth decreased to the same level as in the ischaemic core on days 2 and 8. That of surviving tissue was still above normal on day 2 (103% of control), but had returned to the normal level by day 8. Measurement of ADC combined with perfusion MRI may help distinguish different subregions in acutely hypoperfused brain. PMID:12750863

  19. Detecting the subregion proceeding to infarction in hypoperfused cerebral tissue: a study with diffusion and perfusion weighted MRI

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Y.; Vanninen, R.L.; Vainio, P.A.; Soimakallio, S. [Department of Clinical Radiology, Kuopio University Hospital, P.O. Box 1777, 70211, Kuopio (Finland); Karonen, J.O. [Department of Clinical Radiology, Kuopio University Hospital, P.O. Box 1777, 70211, Kuopio (Finland); Department of Radiology, Mikkeli Central Hospital, Mikkeli (Finland); Nuutinen, J. [Department of Neurology, Kuopio University Hospital, Kuopio (Finland); Perkioe, J. [Department of Radiology, Helsinki University Central Hospital (Finland); Department of Physical Sciences, University of Helsinki (Finland); Functional Brain Imaging Unit, Helsinki Brain Research Centre (Finland); Aronen, H.J. [Department of Clinical Radiology, Kuopio University Hospital, P.O. Box 1777, 70211, Kuopio (Finland); Department of Radiology, Helsinki University Central Hospital (Finland)

    2003-06-01

    Diffusion and perfusion weighted MRI have been widely used in ischaemic stroke. We studied 17 patients in whom ischaemic areas showed an ischaemic core, an area of infarct growth and hypoperfused but ultimately surviving tissue. Apparent diffusion coefficients (ADC) were measured on days 1, 2, and 8 in the three subregions and in contralateral control areas. Cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) were measured in these regions on day 1 perfusion maps. On day 1, the ischaemic core had very low ADC and CBF and increased MTT. The ADC in the ischaemic core gradually increased during the week. The area of infarct growth on day 1 had slightly but significantly decreased ADC (96% of control, P=0.028), moderately decreased CBF and increased MTT. On day 1 the hypoperfused but surviving tissue had slightly but significantly increased ADC (103% of control, P=0.001), mildly decreased CBF and increased CBV and MTT. The ADC of the area of infarct growth decreased to the same level as in the ischaemic core on days 2 and 8. That of surviving tissue was still above normal on day 2 (103% of control), but had returned to the normal level by day 8. Measurement of ADC combined with perfusion MRI may help distinguish different subregions in acutely hypoperfused brain. (orig.)

  20. [Effect of the exposure to factors inducing diffuse damage of cerebral tissue on sleep structure in laboratory rats].

    Science.gov (United States)

    Koval'zon, V M; Dorokhov, V B; Loginov, V V

    2009-01-01

    Effects of strong stress inducing diffuse damage of the brain tissue on subsequent sleep were studied in rats preliminary implanted with chronic electrodes for the neocortical and hippocampal EEG as well as EMG of the neck muscles. An acute and three chronic experimental models were used: general cerebral ischemia induced by a permanent unilateral occlusion of the common carotid artery, hypoxic hypoxia, hypoglycemia, and "penicillinium" epilepsy. Polysomnographic recording was performed either continuously within 24 hrs (in case of the chronic stress model) or 3 hrs daily: from 09 to 12 a.m. (for three acute stress models). In all the models, a significant increase in the paradoxical sleep (PS) percentage was found which reached its maximum within 1-3 days since stress exposure. The following changes were found to be dependent upon the character of the stress factor. In acute stress models, the PS percentage returned to the baseline level within 5-6 days. In the chronic model, the PS percentage returned to baseline level on the 40-45th day after the day of occlusion. The sharp increase in the PS percentage following the exposure to stress factors inducing cerebral tissue damage corroborate the hypothesis of an increase in neural tissue restitution processes during PS periods. PMID:19445391

  1. Design of a tissue oxygenation monitor and verification on human skin

    Science.gov (United States)

    Liu, Hongyuan; Kohl-Bareis, Matthias; Huang, Xiabing

    2011-07-01

    We report the design of a tissue oxygen and temperature monitor. The non-invasive, fibre based device monitors tissue haemoglobin (Hb) and oxygen saturation (SO2) and is based on white-light reflectance spectroscopy.Visible light with wavelengths in the 500 - 650nm range is utilized. The spectroscopic algorithm takes into account the tissue scattering and melanin absorption for the calculation of tissue haemoglobin concentration and oxygen saturation. The monitor can probe superficial layers of tissue with a high spatial resolution (mm3) and a high temporal resolution (40 Hz). It provides an accurate measurement with the accuracy of SO2 at 2 % and high reliability with less than 2 % variation of continuous SO2 measurement over 12 hours. It can also form a modular system when used in conjunction with a laser Doppler monitor, enabling simultaneous measurements of Hb, SO2 and blood flow. We found experimentally that the influence of the source-detector separation on the haemoglobin parameters is small. This finding is discussed by Monte Carlo simulations for the depth sensitivity profile. The influence of probe pressure and the skin pigmentation on the measurement parameters are assessed before in vivo experimental data is presented. The combination with laser Doppler flowmetry demonstrates the importance of a measurement of both the haemoglobin and the blood flow parameters for a full description of blood tissue perfusion. This is discussed in experimental data on human skin during cuff occlusion and after hyperemisation by a pharmacological cream. Strong correlation is observed between tissue oxygen (Hb and SO2) and blood flow measurements.

  2. Contrast enhancement for in vivo visible reflectance imaging of tissue oxygenation.

    Science.gov (United States)

    Crane, Nicole J; Schultz, Zachary D; Levin, Ira W

    2007-08-01

    Results are presented illustrating a straightforward algorithm to be used for real-time monitoring of oxygenation levels in blood cells and tissue based on the visible spectrum of hemoglobin. Absorbance images obtained from the visible reflection of white light through separate red and blue bandpass filters recorded by monochrome charge-coupled devices (CCDs) are combined to create enhanced images that suggest a quantitative correlation between the degree of oxygenated and deoxygenated hemoglobin in red blood cells. The filter bandpass regions are chosen specifically to mimic the color response of commercial 3-CCD cameras, representative of detectors with which the operating room laparoscopic tower systems are equipped. Adaptation of this filter approach is demonstrated for laparoscopic donor nephrectomies in which images are analyzed in terms of real-time in vivo monitoring of tissue oxygenation. PMID:17716397

  3. Evolution of oxygen utilization in multicellular organisms and implications for cell signalling in tissue engineering

    Directory of Open Access Journals (Sweden)

    Katerina Stamati

    2011-11-01

    Full Text Available Oxygen is one of the critically defining elements resulting in the existence of eukaryotic life on this planet. The rise and fall of this element can be tracked through time and corresponds with the evolution of diverse life forms, development of efficient energy production (oxidative phosphorylation in single cell organisms, the evolution of multicellular organisms and the regulation of complex cell phenotypes. By understanding these events, we can plot the effect of oxygen on evolution and its direct influence on different forms of life today, from the whole organism to specific cells within multicellular organisms. In the emerging field of tissue engineering, understanding the role of different levels of oxygen for normal cell function as well as control of complex signalling cascades is paramount to effectively build 3D tissues in vitro and their subsequent survival when implanted.

  4. Acetylbritannilactone Modulates MicroRNA-155-Mediated Inflammatory Response in Ischemic Cerebral Tissues

    OpenAIRE

    Wen, Ya; Zhang, Xiangjian; Dong, Lipeng; Zhao, Jingru; Zhang, Cong; Zhu, Chunhua

    2015-01-01

    Inflammatory responses play a critical role in ischemic brain injury. MicroRNA-155 (miR-155) induces the expression of inflammatory cytokines, and acetylbritannilactone (ABL) exerts potent antiinflammatory actions by inhibiting expression of inflammation-related genes. However, the functions of miR-155 and the actual relationship between ABL and miR-155 in ischemia-induced cerebral inflammation remain unclear. In this study, cerebral ischemia of wild-type (WT) and miR-155−/− mice was induced ...

  5. Non-invasive monitoring of tissue oxygenation during laparoscopic donor nephrectomy

    Directory of Open Access Journals (Sweden)

    Kirk Allan D

    2008-04-01

    Full Text Available Abstract Background Standard methods for assessment of organ viability during surgery are typically limited to visual cues and tactile feedback in open surgery. However, during laparoscopic surgery, these processes are impaired. This is of particular relevance during laparoscopic renal donation, where the condition of the kidney must be optimized despite considerable manipulation. However, there is no in vivo methodology to monitor renal parenchymal oxygenation during laparoscopic surgery. Methods We have developed a method for the real time, in vivo, whole organ assessment of tissue oxygenation during laparoscopic nephrectomy to convey meaningful biological data to the surgeon during laparoscopic surgery. We apply the 3-CCD (charge coupled device camera to monitor qualitatively renal parenchymal oxygenation with potential real-time video capability. Results We have validated this methodology in a porcine model across a range of hypoxic conditions, and have then applied the method during clinical laparoscopic donor nephrectomies during clinically relevant pneumoperitoneum. 3-CCD image enhancement produces mean region of interest (ROI intensity values that can be directly correlated with blood oxygen saturation measurements (R2 > 0.96. The calculated mean ROI intensity values obtained at the beginning of the laparoscopic nephrectomy do not differ significantly from mean ROI intensity values calculated immediately before kidney removal (p > 0.05. Conclusion Here, using the 3-CCD camera, we qualitatively monitor tissue oxygenation. This means of assessing intraoperative tissue oxygenation may be a useful method to avoid unintended ischemic injury during laparoscopic surgery. Preliminary results indicate that no significant changes in renal oxygenation occur as a result of pneumoperitoneum.

  6. Brain Oxygenation Monitoring.

    Science.gov (United States)

    Kirkman, Matthew A; Smith, Martin

    2016-09-01

    A mismatch between cerebral oxygen supply and demand can lead to cerebral hypoxia/ischemia and deleterious outcomes. Cerebral oxygenation monitoring is an important aspect of multimodality neuromonitoring. It is increasingly deployed whenever intracranial pressure monitoring is indicated. Although there is a large body of evidence demonstrating an association between cerebral hypoxia/ischemia and poor outcomes, it remains to be determined whether restoring cerebral oxygenation leads to improved outcomes. Randomized prospective studies are required to address uncertainties about cerebral oxygenation monitoring and management. This article describes the different methods of monitoring cerebral oxygenation, their indications, evidence base, limitations, and future perspectives. PMID:27521197

  7. Circulation time determined by carotid angiography in patients with chronic internal Carotid artery occlusion. Comparison with cerebral blood flow and oxygen metabolism measured by PET

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Hiroshi; Inugami, Atsushi (Research Inst. for Brain and Blood Vessels, Akita (Japan)); Shishido, Fumio (and others)

    1994-10-01

    The degree of collateral circulation in patients with unilaterally chronic internal carotid artery occlusion was estimated by mean transit time of contrast material in rapid sequence carotid angiography (Angiographic MTT), and compared with cerebral blood flow and oxygen metabolism measured by PET. In normal density region on X-ray CT, a significant negative correlation was observed between Angiographic MTT and cerebral blood flow (CBF). This indicates that cerebral blood flow can be estimated by Angiographic MTT. It has been reported that the ratio of cerebral blood volume (CBV) to CBF (CBV/CBF), i.e., mean transit time determined by PET well agreed with OEF, and is good indicator for brain circulation reserve. In this study, no significant correlation was observed between Angiographic MTT and CBV/CBF. However, a significant positive correlation was observed between Angiographic MTT and oxygen extraction fraction (OEF), and no significant correlation was observed between Angiographic MTT and oxygen consumption rate (CMRO[sub 2]). These indicates that Angiographic MTT may be indicator for brain circulation reserve. (author).

  8. The dual roles of red blood cells in tissue oxygen delivery

    DEFF Research Database (Denmark)

    Jensen, Frank Bo

    2009-01-01

    Vertebrate red blood cells (RBCs) seem to serve tissue oxygen delivery in two distinct ways. Firstly, RBCs enable the adequate transport of O2 between respiratory surfaces and metabolizing tissues by means of their high intracellular concentration of hemoglobin (Hb), appropriate allosteric...... interactions between Hb ligand-binding sites, and an adjustable intracellular chemical environment that allows fine-tuning of Hb O2 affinity. Secondly, RBCs may sense tissue O2 requirements via their degree of deoxygenation when they travel through the microcirculation and release vasodilatory compounds that...... enhance blood flow in hypoxic tissues. This latter function could be important in matching tissue O2 delivery with local O2 demand. Three main mechanisms by which RBCs can regulate their own distribution in the microcirculation have been proposed. These are: (1) deoxygenation-dependent release of ATP from...

  9. The therapeutic effect and prognosis of acute cerebral infarction patients with atrial fibrillation treated by intravenous thrombolysis with recombinant tissue plasminogen activator

    Institute of Scientific and Technical Information of China (English)

    尤寿江

    2013-01-01

    Objective To investigate the efficacy and safety of intravenous thrombolysis with recombinant tissue plasminogen activator (rt-PA) in acute cerebral infarct patients with atrial fibrillation (AF) and the predicting factors of poor prognosis.Methods Totally 162 patients with acute cerebral infarct were treated with rt-PA within 4.5hours from the onset.According to past history and the electrocardiogram,the patients was classified into AF

  10. The relationship between the cerebral blood flow, oxygen consumption and glucose metabolism in primary degenerative dementia

    International Nuclear Information System (INIS)

    The CBF, CMRO2 and CMRGlu were measured in patients with primary degenerative dementia including 5 patients with dementia of Alzheimer's type and 4 patients with Pick's disease, and then the correlation between the cerebral blood flow and energy metabolism was evaluated. The control subjects consisted of 5 age-matched normal volunteers. The CBF, CMRO2 and CMRGlu decreased in the bilateral frontal, temporal and parietal regions in the patients with Alzheimer's dementia, while they decreased in the bilateral frontal and temporal regions in the patients with Pick's disease. Both the CBF and CMRO2 were closely correlated with each other. However, the CMRGlu was more severely impaired than the CBF or CMRO2 in both pathological conditions. These results suggested that CMRGlu began to decrease before the reduction of the aerobic metabolism and thus measuring the CMRGlu is considered to be the most sensitive method for detecting abnormal regions in primary degenerative dementia. (author)

  11. Effect of end-tidal CO2 clamping on cerebrovascular function, oxygenation, and performance during 15-km time trial cycling in severe normobaric hypoxia: the role of cerebral O2 delivery.

    Science.gov (United States)

    Fan, Jui-Lin; Bourdillon, Nicolas; Kayser, Bengt

    2013-08-01

    During heavy exercise, hyperventilation-induced hypocapnia leads to cerebral vasoconstriction, resulting in a reduction in cerebral blood flow (CBF). A reduction in CBF would impair cerebral O2 delivery and potentially account for reduced exercise performance in hypoxia. We tested the hypothesis that end-tidal Pco2 (PETCO2) clamping in hypoxic exercise would prevent the hypocapnia-induced reduction in CBF during heavy exercise, thus improving exercise performance. We measured PETCO2, middle cerebral artery velocity (MCAv; index of CBF), prefrontal cerebral cortex oxygenation (cerebral O2Hb; index of cerebral oxygenation), cerebral O2 delivery (DO2), and leg muscle oxygenation (muscle O2Hb) in 10 healthy men (age 27 ± 7 years; VO2max 63.3 ± 6.6 mL/kg/min; mean ± SD) during simulated 15-km time trial cycling (TT) in normoxia and hypoxia (FIO2 = 0.10) with and without CO2 clamping. During exercise, hypoxia elevated MCAv and lowered cerebral O2Hb, cerebral DO2, and muscle O2Hb (P exercise in both normoxic and hypoxic conditions (P effect on either cerebral and muscle O2Hb (P = 0.118 and P = 0.124). Nevertheless, CO2 clamping elevated cerebral DO2 during TT in both normoxic and hypoxic conditions (P hypoxia and tended to have a greater effect on TT performance in hypoxia compared to normoxia (P = 0.097). However, post hoc analysis revealed no effect of CO2 clamping on TT performance either in normoxia (P = 0.588) or in hypoxia (P = 0.108). Our findings confirm that the hyperventilation-induced hypocapnia and the subsequent drop in cerebral oxygenation are unlikely to be the cause of the reduced endurance exercise performance in hypoxia. PMID:24303142

  12. Hyperbaric oxygen treatment induces dynamic ATPase activity changes in the rat brain following transient global cerebral ischemia-reperfusion

    Institute of Scientific and Technical Information of China (English)

    Shiming Xu; Hongjuan Wang; Tongnan Gu; Xiuyan Zhou; Rui Chen

    2008-01-01

    BACKGROUND: Energy depletion, induced by ischemia or hypoxia, is one of the first events in neuronal injury. OBJECTIVE: To investigate the dynamic changes of Na+-K+-ATPase and Ca2+-ATPase activity in the rat brain following transient global cerebral ischemia-reperfusion (IR), as well as the effects of hyperbaric oxygen (HBO) treatment. DESIGN, TIME AND SETTING: A randomized and controlled animal study was performed in the Department of Biochemistry and Molecular Biology, Capital Medical University between February and December 2006. MATERIALS: Clean-grade, female, Sprague Dawley rats were provided by the Animal Research Department of Capital Medical University (License number: SYXK11-00-0047). Na+-K+-ATPase and Ca2+-ATPase kits were provided by Nanjing Jiancheng Bioengineering Institute (Nanjing, China). A hyperbaric oxygen chamber (DWC150-300) was supplied by Shanghai 701 Medical Oxygen Chamber Factory (Shanghai, China). METHODS: Sixty-three rats were randomly divided into nine groups: sham operated group (sham-O) as control, groups of IR, and groups treated with hyperbaric oxygen (HBO) after IR. Animal from the IR and HBO groups were sacrificed after four different survival intervals of 6, 24, 48 and 96 hours, respectively. Each group consisted of seven rats. The rats of HBO groups were placed into the hyperbaric chamber. The HBO chamber was flushed with pure oxygen for 5 minutes, followed by a gradual rise in pressure over 5 minutes and stabilization at 0.2 MPa. Then, pure oxygen was supplied for 45 minutes in stabilized pressure, followed by gradually reduced pressure over 15 minutes. The rats of the 6-h HBO group were placed into the HBO chamber following reperfusion for 3 hours on the first day, which was repeated on three consecutive days, always at the same time. Rats in the sham-O group and IR group remained under normal atmospheric pressure. MAIN OUTCOME MEASURES: The Na+-K+-ATPase and Ca2+-ATPase activity in rat brain homogenate was detected by the

  13. Increased cerebral oxygen extraction capacity in patients with Alzheimer’s disease

    DEFF Research Database (Denmark)

    Eskildsen, Simon Fristed; Gyldensted, Louise; Nagenthiraja, Kartheeban;

    Vascular risk factors are suspected to play a role in the etiology of Alzheimer’s disease. Recently, a model that relates capillary dysfunction to the development of AD was proposed [1]. The model predicts that increased capillary dysfunction leads to increased oxygen extraction in order to support...

  14. Oxygen regulation of uricase and sucrose synthase synthesis in soybean callus tissue is exerted at the mRNA level

    DEFF Research Database (Denmark)

    Xue, Z T; Larsen, K; Jochimsen, B U

    1991-01-01

    The effect of lowering oxygen concentration on the expression of nodulin genes in soybean callus tissue devoid of the microsymbiont has been examined. Poly(A)+ RNA was isolated from tissue cultivated in 4% oxygen and in normal atmosphere. Quantitative mRNA hybridization experiments using nodule...

  15. Tissue gradients of energy metabolites mirror oxygen tension gradients in a rat mammary carcinoma model

    International Nuclear Information System (INIS)

    Purpose: It has been shown that oxygen gradients exist in R3230AC tumors grown in window chambers. The fascial surface is better oxygenated than the tumor surface. The purpose of the present study was to determine whether gradients exist for energy metabolites and other end points related to oxygen transport. Methods and Materials: Imaging bioluminescence was used to measure ATP, glucose, and lactate in cryosections of R3230AC tumors. Mean vessel density and hypoxic tissue fraction were assessed using immunohistochemistry. Tumor redox ratio was assessed by redox ratio scanning. Results: Lactate content and hypoxic fraction increased, whereas ATP, glucose, redox ratio, and vessel density decreased from the fascial to the tumor surface. Conclusions: The data support a switch from aerobic to anaerobic metabolism concomitant with the PO2 gradient. The vascular hypoxia that exists in perfused vessels at the tumor surface leads to macroscopic tissue regions with restricted oxygen availability and altered metabolic status. Methods to reduce tumor hypoxia may have to take this into account if such gradients exist in human tumors. The results also have implications for hypoxia imaging, because macroscopic changes in PO2 (or related parameters) will be easier to see than PO2 gradients limited to the diffusion distance of oxygen

  16. Discussing the model of cerebral watershed infarction and leukoaraiosis based on the perforating artery-neural tissue units

    Directory of Open Access Journals (Sweden)

    Yong-Peng Yu

    2015-01-01

    Full Text Available At present, there is still controversy in the etiology and pathogenesis of cerebral watershed infarction (CWI. The classification of watershed infarction is also confusing. Great changes have taken place in the knowledge of CWI with the development of the medical and imaging technology. Based on the concept of the perforating artery-neural tissue units, the innovative speculation on the relation among leukoaraiosis (LA (belong to white matter lesions, CWI and the mechanism of the perforating artery infarction formation was proposed in this paper. Based on the combination possibility of different perforating artery-neural tissue units,  the CWI was classified as lateral watershed infarction  (anterior cortical and posterior cortical watershed infarction, internal watershed infarction (anterior and interior type, posterior and interior type and interior type and deep watershed infarction (deep anterior type, deep posterior type and the various subtypes. This paper suggests that LA might be caused by chronic watershed cerebral ischemia change,  and perforating artery infarction and CWI are the same strain. This inference may help us to understand the relation among the mechanisms of the perforating artery infarction, CWI and LA.

  17. Artificial membrane-binding proteins stimulate oxygenation of stem cells during engineering of large cartilage tissue

    Science.gov (United States)

    Armstrong, James P. K.; Shakur, Rameen; Horne, Joseph P.; Dickinson, Sally C.; Armstrong, Craig T.; Lau, Katherine; Kadiwala, Juned; Lowe, Robert; Seddon, Annela; Mann, Stephen; Anderson, J. L. Ross; Perriman, Adam W.; Hollander, Anthony P.

    2015-06-01

    Restricted oxygen diffusion can result in central cell necrosis in engineered tissue, a problem that is exacerbated when engineering large tissue constructs for clinical application. Here we show that pre-treating human mesenchymal stem cells (hMSCs) with synthetic membrane-active myoglobin-polymer-surfactant complexes can provide a reservoir of oxygen capable of alleviating necrosis at the centre of hyaline cartilage. This is achieved through the development of a new cell functionalization methodology based on polymer-surfactant conjugation, which allows the delivery of functional proteins to the hMSC membrane. This new approach circumvents the need for cell surface engineering using protein chimerization or genetic transfection, and we demonstrate that the surface-modified hMSCs retain their ability to proliferate and to undergo multilineage differentiation. The functionalization technology is facile, versatile and non-disruptive, and in addition to tissue oxygenation, it should have far-reaching application in a host of tissue engineering and cell-based therapies.

  18. Vital Organ Tissue Oxygenation After Serial Normovolemic Exchange Transfusion With HBOC-201 in Anesthetized Swine

    OpenAIRE

    Muir, William W; Ilangovan, Govindasamy; Zweier, Jay L.; Moon-Massat, Paula F.; Rentko, Virginia T.

    2011-01-01

    This study determined the effects of serial, normovolemic, stepwise exchange transfusions with either 6% human serum albumin (HSA) or the hemoglobin-based oxygen carrier, HBOC-201, on tissue oxygenation of the heart, brain and kidney in intact anaesthetized pigs. Exchange transfusions to 10%, 30% and 50% of the pigs total blood volume were completed at a withdrawal rate of 1.0 ml/kg/min followed by an infusion rate of 0.5 ml/kg/min of HBOC-201 or iso-oncotically matched 6% HSA. Measurements i...

  19. Validation of quantitative estimation of tissue oxygen extraction fraction and deoxygenated blood volume fraction in phantom and in vivo experiments by using MRI.

    Science.gov (United States)

    Sedlacik, Jan; Reichenbach, Jürgen R

    2010-04-01

    The blood oxygenation level dependent signal of cerebral tissue can be theoretically derived using a network model formed by randomly oriented infinitely long cylinders. The validation of this model by phantom and in vivo experiments is still an object of research. A network phantom was constructed of solid polypropylene strings immersed in silicone oil, which essentially eliminated the effect of spin diffusion. The volume fraction and magnetic property of the string network was predetermined by independent methods. Ten healthy volunteers were measured for in vivo demonstration. The gradient echo sampled spin echo signal was evaluated with the cylinder network model. We found a strong interdependency between the two network characterizing parameters deoxygenated blood volume and oxygen extraction fraction. Here, different sets of deoxygenated blood volume/oxygen extraction fraction values were able to describe the measured signal equally well. However, by setting one parameter constant to a predetermined value, reasonable estimates of the other parameter were obtained. The same behavior was found for the in vivo demonstration. The signal theory of the cylinder network was validated by a well-characterized phantom. However, the found interdependency that was found between deoxygenated blood volume and oxygen extraction fraction requires an independent estimation of one variable to determine reliable values of the other parameter. PMID:20373392

  20. Comparative study of cerebral blood perfusion SPECT imaging and CT scan in evaluation of the curative effect of hyperbaric oxygen in patients with post-traumatic brain syndrome

    International Nuclear Information System (INIS)

    Objective: To comparatively study the results of cerebral SPECT and cerebral CT before and after hyperbaric oxygen (HBO) treatment in post-traumatic brain syndrome. Methods: HBO was used to treat 288 patients with post-traumatic brain syndrome for two courses, and made therapeutic surveillance and comparative analysis with 99Tcm-ECD SPECT, CT before and after treatment. Results: Before treatment, the positive rate of cerebral SPECT was 80.6%, but the positive rate of CT was only 10.2%; after treatment, 90% of SPECT became negative, and the clinical symptoms of the patients disappeared as SPECT became negative. The results showed that HBO treatment could evidently improve rCBF, and showed that SPECT was superior to CT in surveillance of HBO treatment. Conclusions: 99Tcm-ECD SPECT could play an important role in the diagnosis of post-traumatic brain syndrome and the therapeutic surveillance of HBO

  1. Localized increase of tissue oxygen tension by magnetic targeted drug delivery

    Science.gov (United States)

    Liong, Celine; Ortiz, Daniel; Ao-ieong, Eilleen; Navati, Mahantesh S.; Friedman, Joel M.; Cabrales, Pedro

    2014-07-01

    Hypoxia is the major hindrance to successful radiation therapy of tumors. Attempts to increase the oxygen (O2) tension (PO2) of tissue by delivering more O2 have been clinically disappointing, largely due to the way O2 is transported and released by the hemoglobin (Hb) within the red blood cells (RBCs). Systemic manipulation of O2 transport increases vascular resistance due to metabolic autoregulation of blood flow to prevent over oxygenation. This study investigates a new technology to increase O2 delivery to a target tissue by decreasing the Hb-O2 affinity of the blood circulating within the targeted tissue. As the Hb-O2 affinity decreases, the tissue PO2 to satisfy tissue O2 metabolic needs increases without increasing O2 delivery or extraction. Paramagnetic nanoparticles (PMNPs), synthetized using gadolinium oxide, were coated with the cell permeable Hb allosteric effector L35 (3,5-trichlorophenylureido-phenoxy-methylpropionic acid). L35 decreases Hb affinity for O2 and favors the release of O2. The L35-coated PMNPs (L35-PMNPs) were intravenously infused (10 mg kg-1) to hamsters instrumented with the dorsal window chamber model. A magnetic field of 3 mT was applied to localize the effects of the L35-PMNPs to the window chamber. Systemic O2 transport characteristics and microvascular tissue oxygenation were measured after administration of L35-PMNPs with and without magnetic field. The tissue PO2 in untreated control animals was 25.2 mmHg. L35-PMNPs without magnetic field decreased tissue PO2 to 23.4 mmHg, increased blood pressure, and reduced blood flow, largely due to systemic modification of Hb-O2 affinity. L35-PMNPs with magnetic field increased tissue PO2 to 27.9 mmHg, without systemic or microhemodynamic changes. These results indicate that localized modification of Hb-O2 affinity can increase PO2 of target tissue without affecting systemic O2 delivery or triggering O2 autoregulation mechanisms. This technology can be used to treat local hypoxia and to

  2. Localized increase of tissue oxygen tension by magnetic targeted drug delivery

    International Nuclear Information System (INIS)

    Hypoxia is the major hindrance to successful radiation therapy of tumors. Attempts to increase the oxygen (O2) tension (PO2) of tissue by delivering more O2 have been clinically disappointing, largely due to the way O2 is transported and released by the hemoglobin (Hb) within the red blood cells (RBCs). Systemic manipulation of O2 transport increases vascular resistance due to metabolic autoregulation of blood flow to prevent over oxygenation. This study investigates a new technology to increase O2 delivery to a target tissue by decreasing the Hb-O2 affinity of the blood circulating within the targeted tissue. As the Hb-O2 affinity decreases, the tissue PO2 to satisfy tissue O2 metabolic needs increases without increasing O2 delivery or extraction. Paramagnetic nanoparticles (PMNPs), synthetized using gadolinium oxide, were coated with the cell permeable Hb allosteric effector L35 (3,5-trichlorophenylureido-phenoxy-methylpropionic acid). L35 decreases Hb affinity for O2 and favors the release of O2. The L35-coated PMNPs (L35-PMNPs) were intravenously infused (10 mg kg−1) to hamsters instrumented with the dorsal window chamber model. A magnetic field of 3 mT was applied to localize the effects of the L35-PMNPs to the window chamber. Systemic O2 transport characteristics and microvascular tissue oxygenation were measured after administration of L35-PMNPs with and without magnetic field. The tissue PO2 in untreated control animals was 25.2 mmHg. L35-PMNPs without magnetic field decreased tissue PO2 to 23.4 mmHg, increased blood pressure, and reduced blood flow, largely due to systemic modification of Hb-O2 affinity. L35-PMNPs with magnetic field increased tissue PO2 to 27.9 mmHg, without systemic or microhemodynamic changes. These results indicate that localized modification of Hb-O2 affinity can increase PO2 of target tissue without affecting systemic O2 delivery or triggering O2 autoregulation mechanisms. This technology can be used to treat local hypoxia and to

  3. Localized Increase of Tissue Oxygen Tension by Magnetic Targeted Drug Delivery

    Science.gov (United States)

    Liong, Celine; Ortiz, Daniel; Ao-ieong, Eilleen; Navati, Mahantesh S.; Friedman, Joel M.; Cabrales, Pedro

    2014-01-01

    Hypoxia is the major hindrance to successful radiation therapy of tumors. Attempts to increase the oxygen (O2) tension (PO2) of tissue by delivering more O2 have been clinically disappointing, largely due to the way O2 is transported and released by the hemoglobin (Hb) within the red blood cells (RBCs). Systemic manipulation of O2 transport increases vascular resistance due to metabolic autoregulation of blood flow to prevent over oxygenation. This study investigates a new technology to increase O2 delivery to a target tissue by decreasing the Hb-O2 affinity of the blood circulating within the targeted tissue. As the Hb-O2 affinity decreases, the tissue PO2 to satisfy tissue O2 metabolic needs increases, without increasing O2 delivery or extraction. Paramagnetic nanoparticles (PMNPs) synthetized using gadolinium oxide, were coated with the cell permeable Hb allosteric effector, L35 (3,5-trichlorophenylureido-phenoxy-methylpropionic acid). L35 decreases Hb affinity for O2 and favors the release of O2. The L35-coaded PMNPs (L35-PMNPs) were intravenously infused (10 mg/kg) to hamster instrumented with the dorsal window chamber model. Magnetic field of 3 mT was applied to localize the effects of the L35-PMNPs to the window chamber. Systemic O2 transport characteristics and microvascular tissue oxygenation were measured after L35-PMNPs administration with and without magnetic field. The tissue PO2 untreated control animals was 25.2 mmHg. L35-PMNP without magnetic field decreased tissue PO2 to 23.4 mmHg, increased blood pressure and reduced blood flow, largely due to systemic modification of Hb-O2 affinity. L35-PMNP with magnetic field increased tissue PO2 to 27.9 mmHg, without systemic or microhemodynamics changes. These results indicate that localized modification of Hb-O2 affinity can increase PO2 of target tissue, without affecting systemic O2 delivery or triggering O2 autoregulation mechanisms. This technology can be used to treat local hypoxia and to increase O2 in

  4. Autoradiographic determination of regional cerebral blood flow and metabolism in conscious rats after fluid resuscitation from haemorrhage with a haemoglobin-based oxygen carrier.

    Science.gov (United States)

    Waschke, K F; Albrecht, D M; van Ackern, K; Kuschinsky, W

    1994-10-01

    The effects of resuscitation fluids on the brain have been investigated in previous studies by global measurements of cerebral blood flow and metabolism. In this study we have examined the effects of a novel haemoglobin-based oxygen carrier on local cerebral blood flow (LCBF) and local cerebral glucose utilization (LCGU) after resuscitation from a volume-controlled haemorrhage of 30 min (3.0 ml/100 g body weight) with ultrapurified, polymerized, bovine haemoglobin (UPBHB). LCBF and LCGU were measured in 34 brain structures of conscious rats 2 h after resuscitation using quantitative iodo(14C)antipyrine and 2-(14C)-deoxy-D-glucose methods. The data were compared with a control group without haemorrhage and fluid resuscitation. In the haemorrhage group, LCBF increased after resuscitation by 12-56% in the different brain structures (mean 36%). LCGU changed less (0 to +18%, mean +9%). In the control group there was a close relationship between LCGU and LCBF (r = 0.95). After fluid resuscitation the relationship was preserved (r = 0.95), although it was reset at a higher ratio of LCBF to LCGU (P < 0.05). We conclude that fluid resuscitation of a 30 min volume-controlled haemorrhage using the haemoglobin-based oxygen carrier, UPBHB, induced a moderate degree of heterogeneity in the resulting changes of LCGU and LCBF. Local disturbances of cerebral blood flow or metabolism were not observed. PMID:7999496

  5. Reduced blood flow response to acetazolamide reflects pre-existing vasodilation and decreased oxygen metabolism in major cerebral arterial occlusive disease

    International Nuclear Information System (INIS)

    A decrease in the cerebral blood flow (CBF) response to acetazolamide may indicate an increase in cerebral blood volume (CBV) caused by reduced perfusion pressure in patients with major cerebral artery steno-occlusive lesions. However, a decrease in cerebral metabolic rate of oxygen (CMRO2) caused by ischemic changes may also decrease the CBF response to acetazolamide by decreasing the production of carbon dioxide. The purpose of this study was to determine whether the values of CBV and CMRO2 are independent predictors of the CBF response to acetazolamide in major cerebral arterial occlusive disease. We used positron emission tomography to study 30 patients with major cerebral artery steno-occlusive lesions. The CBF response to acetazolamide was assessed by measuring baseline CBF and CBF 10 min after an intravenous injection of 1 g of acetazolamide. Multivariate analysis was used to test the independent predictive value of the CBV and CMRO2 at baseline with respect to the percent change in CBF during acetazolamide administration. Both increased CBV and decreased CMRO2 were significant and independent predictors of the reduced CBF response to acetazolamide. CBV accounted for 25% of the variance in the absolute change in CBF during acetazolamide administration and 42% of the variance in the percent change in CBF, whereas CMRO2 accounted for 19% and 4% of the variance, respectively. In patients with major cerebral arterial occlusive disease, a decrease in CMRO2 may contribute to the reduced CBF response to acetazolamide, although an increase in CBV appears to be the major contributing factor. (orig.)

  6. Tissue oxygenation during exercise measured with NIRS: reproducibility and influence of wavelengths.

    Science.gov (United States)

    Gerz, Erwin; Geraskin, Dmitri; Franke, Julia; Platen, Petra; Steimers, André; Kohl-Bareis, Matthias

    2013-01-01

    Near-infrared spectroscopy (NIRS) is widely used for the measurement of skeletal muscle oxygenation during exercise as it reflects muscle metabolism, and most studies report a large variability between subjects. Here we assess the data quality of tissue oxygen saturation (SO2) and oxygenated (oxyHb) and deoxygenated (deoxyHb) haemoglobin concentrations recorded during an incremental cycling protocol in nine healthy volunteers. The protocol was repeated three times on the same day and a fourth session on a different day to estimate the reproducibility of the method with a broadband, spatially resolved spectroscopy (SRS) system. We found that the inter-subject variation in SO2 (standard deviation ≈ 6 %) was considerably larger than the reproducibility (≈ 1.5 %) both for the same-day and different-day tests. The reproducibility of changes in SO2 was better than 1 %. PMID:23852492

  7. Influence of Negative-Pressure Wound Therapy on Tissue Oxygenation of the Foot

    OpenAIRE

    Shon, Yoo-Seok; Lee, Ye-Na; Jeong, Seong-Ho; Dhong, Eun-Sang; Han, Seung-Kyu

    2014-01-01

    Background Negative-pressure wound therapy (NPWT) is believed to accelerate wound healing by altering wound microvascular blood flow. Although many studies using laser Doppler have found that NPWT increases perfusion, recent work using other modalities has demonstrated that perfusion is reduced. The purpose of this study was to investigate the influence of NPWT on tissue oxygenation of the foot, which is the most sensitive region of the body to ischemia. Methods Transcutaneous partial pressur...

  8. Single event-related changes in cerebral oxygenated hemoglobin using word game in schizophrenia

    Directory of Open Access Journals (Sweden)

    Fujiki R

    2014-12-01

    Full Text Available Ryo Fujiki,1,2 Kiichiro Morita,1,2 Mamoru Sato,1,2 Yuji Yamashita,1,2 Yusuke Kato,1,2 Yohei Ishii,2 Yoshihisa Shoji,1,2 Naohisa Uchimura1 1Department of Neuropsychiatry, Kurume University, 2Cognitive and Molecular Research Institute of Brain Diseases, Kurume University School of Medicine, Kurume-City, Japan Abstract: Neuroimaging studies have been conducted using word generation tasks and have shown greater hypofrontality in patients with schizophrenia compared with healthy subjects. In this study, we compared the characteristics of oxygenated hemoglobin changes involved in both phonological and categorical verbal fluency between 35 outpatients with schizophrenia and 35 healthy subjects during a Japanese “shiritori” task using single-event-related near-infrared spectroscopy. During this task, the schizophrenic patients showed significantly smaller activation in the prefrontal cortex area than the controls. In addition, a significant positive correlation was obtained between oxygenated hemoglobin changes (prefrontal cortex area, inferior parietal area and the severity of positive psychiatric symptoms. It is possible that hypofrontality of patients may be a diagnostic assistance tool for schizophrenia, and that the relationship between activation and positive syndrome scores may be of help in predicting functional outcome in patients. Keywords: word production task, single-event-related near-infrared spectroscopy, schizophrenia, hypofrontality, biological marker

  9. Comparison of the effects of on-pump and off-pump coronary artery bypass surgery on cerebral oxygen saturation using near-infrared spectroscopy

    OpenAIRE

    Demir, Guray; Çukurova, Zafer; Eren, Gülay; Hergünsel, Oya

    2014-01-01

    Background Central nervous system complications are the most clinically important of those affecting mortality in patients undergoing coronary artery surgery. Newly developed sophisticated techniques and surgical interventions obviating the need for cardiopulmonary pumps have facilitated avoidance of these complications. In this study, we compared the impact of on-pump and off-pump coronary artery bypass surgery on cerebral oxygenation using near-infrared spectroscopy. Methods This study incl...

  10. Influence of skin blood flow and source-detector distance on near-infrared spectroscopy-determined cerebral oxygenation in humans

    DEFF Research Database (Denmark)

    Hirasawa, Ai; Yanagisawa, Shintaro; Tanaka, Naoki;

    2015-01-01

    semi-recumbent position, while extracranial blood flow was restricted by application of four different pressures (+20 to +80 mmHg) to the left temporal artery. The O2 Hb was measured at the forehead via a multidistance probe (source-detector distance; 15, 22·5 and 30 mm), and SkBF was determined by...... to 30 mm. Therefore, new algorithms need to be developed for unbiased NIRS detection of cerebral oxygenation....

  11. Contribution of reactive oxygen species to cerebral amyloid angiopathy, vasomotor dysfunction, and microhemorrhage in aged Tg2576 mice

    OpenAIRE

    Han, Byung Hee; Zhou, Meng-liang; Johnson, Andrew W; Singh, Itender; Liao, Fan; Vellimana, Ananth K.; Nelson, James W.; Milner, Eric; Cirrito, John R.; Basak, Jacob; Yoo, Min; Dietrich, Hans H.; Holtzman, David M.; Zipfel, Gregory Joseph

    2015-01-01

    One of the hallmarks of Alzheimer’s disease (AD) is cerebral amyloid angiopathy (CAA), which is a strong and independent risk factor for cerebral hemorrhage, ischemic stroke, and dementia. However, the mechanisms by which CAA contributes to these conditions are poorly understood. Results from the present study provide strong evidence that vascular oxidative stress plays a causal role in CAA-induced cerebrovascular dysfunction, CAA-induced cerebral hemorrhage, and CAA formation, itself. They a...

  12. Effects of Repetitive Hyperbaric Oxygen Treatment in Patients with Acute Cerebral Infarction: A Pilot Study

    Directory of Open Access Journals (Sweden)

    Cheng-Hsin Chen

    2012-01-01

    Full Text Available The role of hyperbaric oxygen therapy (HBOT in the treatment of acute ischemic stroke is controversial. This prospective study assessed the efficacy and safety of HBOT as adjuvant treatment on 46 acute ischemic stroke in patients who did not receive thrombolytic therapy. The HBOT group (n=16 received conventional medical treatment with 10 sessions of adjunctive HBOT within 3–5 days after stroke onset, while the control group (n=30 received the same treatment but without HBOT. Early (around two weeks after onset and late (one month after onset outcomes (National Institutes of Health Stroke Scale, NIHSS scores and efficacy (changes of NIHSS scores of HBOT were evaluated. The baseline clinical characteristics were similar in both groups. Both early and late outcomes of the HBOT group showed significant difference (P≤0.001. In the control group, there was only significant difference in early outcome (P=0.004. For early efficacy, there was no difference when comparing changes of NIHSS scores between the two groups (P=0.140 but there was statistically significant difference when comparing changes of NIHSS scores at one month (P≤0.001. The HBOT used in this study may be effective for patients with acute ischemic stroke and is a safe and harmless adjunctive treatment.

  13. A Porous Tissue Engineering Scaffold Selectively Degraded by Cell-Generated Reactive Oxygen Species

    Science.gov (United States)

    Martin, John R.; Gupta, Mukesh K.; Page, Jonathan M.; Yu, Fang; Davidson, Jeffrey M.; Guelcher, Scott A.

    2014-01-01

    Biodegradable tissue engineering scaffolds are commonly fabricated from poly(lactide-co-glycolide) (PLGA) or similar polyesters that degrade by hydrolysis. PLGA hydrolysis generates acidic breakdown products that trigger an accelerated, autocatalytic degradation mechanism that can create mismatched rates of biomaterial breakdown and tissue formation. Reactive oxygen species (ROS) are key mediators of cell function in both health and disease, especially at sites of inflammation and tissue healing, and induction of inflammation and ROS are natural components of the in vivo response to biomaterial implantation. Thus, polymeric biomaterials that are selectively degraded by cell-generated ROS may have potential for creating tissue engineering scaffolds with better matched rates of tissue in-growth and cell-mediated scaffold biodegradation. To explore this approach, a series of poly(thioketal) (PTK) urethane (PTK-UR) biomaterial scaffolds were synthesized that degrade specifically by an ROS-dependent mechanism. PTK-UR scaffolds had significantly higher compressive moduli than analogous poly(ester urethane) (PEUR) scaffolds formed from hydrolytically-degradable ester-based diols (p < 0.05). Unlike PEUR scaffolds, the PTK-UR scaffolds were stable under aqueous conditions out to 25 weeks but were selectively degraded by ROS, indicating that their biodegradation would be exclusively cell-mediated. The in vitro oxidative degradation rates of the PTK-URs followed first-order degradation kinetics, were significantly dependent on PTK composition (p < 0.05), and correlated to ROS concentration. In subcutaneous rat wounds, PTK-UR scaffolds supported cellular infiltration and granulation tissue formation, followed first-order degradation kinetics over 7 weeks, and produced significantly greater stenting of subcutaneous wounds compared to PEUR scaffolds. These combined results indicate that ROS-degradable PTK-UR tissue engineering scaffolds have significant advantages over analogous

  14. Changes in tumor tissue oxygenation during microwave hyperthermia-clinical relevance

    International Nuclear Information System (INIS)

    Tissue oxygen levels, blood flow and temperature were determined using a multiwire electrode system carried by insertable sutures into cancerous tissues in patients undergoing microwave hyperthermia treatments in different regions of the body. TpO/sub 2/ was determined using a 25 micron gold in teflon wire. Temperature was measured using a 100 micron copper-constantan microthermocouple placed at the same point as the O/sub 2/ electrode. Blood flow was determined using the thermal washout method. Tumors were heated using air cooled microwave applicators at a frequency of 915 or 300 MHz. As previously described TpO/sub 2/ and flow increase in tumor as temperatures increase to 410C and then decrease (microcirculation ''breaking point''). In the present study this response was reproduced in over 25 treatment sessions. However, as treatment progresses (patients are treated for 1 hour 10 times, twice weekly, and concomitantly receive 4000 rads of ionizing radiation) the initial increase of blood flow and TpO/sub 2/ is reduced and there is an immediate decrease in tissue oxygenation. A correlation between microvascular tumor physiological changes and tumor treatment responses is being developed

  15. A ‘tissue model’ to study the plasma delivery of reactive oxygen species

    International Nuclear Information System (INIS)

    We demonstrate the utility of a ‘tissue model’ to monitor the delivery of plasma jet-generated reactive oxygen species (ROS). We report on helium plasma jet interactions both across the surface and into the subsurface (defined as 150 µm to 1.5 mm) of the tissue model. The model comprises a gelatin gel encapsulating a homogeneously dispersed chemical or biological reporter molecule. Jet–surface interactions result in (i) star shaped patterns that resemble those previously reported for surface-plasma streamers on insulators (as imaged by Pockels sensing) and (ii) ‘filled’ or hollow circular surface features, which resemble the ‘killing’ patterns seen in plasma jet treatments of bacterial lawns. The use of reporter molecules show that plasma can deliver ROS from 150 µm to 1.5 mm below the tissue surface. Subsurface delivery of ROS is consistent with the use of plasma to decontaminate wounds (covered by wound exudate and clotted blood), the deactivation of whole biofilms, plasma-enhanced drug delivery through skin and the destruction of solid tumours. From the data presented, we argue that in these four cases (and others) ROS may be capable of directly accessing a tissue's subsurface, as opposed to other proposed mechanisms, which involve stimulating surface reactions that trigger a cascade of biomolecular signalling events (into the tissue). (fast track communication)

  16. Non-invasive Assessment of Neonatal Brain Oxygen Metabolism: A Review of Newly Available Techniques

    OpenAIRE

    Liu, Peiying; Chalak, Lina F.; Lu, Hanzhang

    2014-01-01

    Because oxidative metabolism is the primary form of energy production in the brain, the amount of oxygen consumed by the brain, denoted by a physiological parameter termed cerebral metabolic rate of oxygen (CMRO2), represents a key marker for tissue viability and brain function. Quantitative assessment of cerebral oxygen metabolism in the neonate may provide an important marker in better understanding normal brain development and in making diagnosis and treatment decisions in neonatal brain i...

  17. Correlation between quantitative EEG and cerebral blood flow and oxygen metabolism in patients with dementia of Alzheimer type

    International Nuclear Information System (INIS)

    Quantitative scalp EEG and cerebral blood flow (CBF) and oxygen metabolism (CMRO2) measured by the steady-state 15O technique and positron emission tomography were studied in 19 patients with mild to moderate dementia of Alzheimer type (DAT) and age-matched controls (EEG=19, PET=6). Scalp electrodes were placed according to the international 10-20 method except for Cz, T3, and T4. To evaluate the relative changes in power for each frequency band between the two groups, the percentage power fraction (percentage power for each frequency band at a site compared to the total power at that site; %delta for 2.0-3.8 Hz, %theta for 4.0-7.8 Hz, %alpha for 8.0-12.8 Hz, %beta for 13.0-25.4 Hz) was calculated. Compared with controls, DAT patients showed a significant decrease in %alpha, while significant increases in %theta at all electrodes, and significant increases in %delta at the temporal, parietal and occipital electrodes were observed. The patient group displayed a significant decrease in rCBF and rCMRO2 in the parietal, temporal and frontal cortices, but the reduction in rCMRO2 was less remarkable than that of rCBF. %Theta at P3, O1 and O2 showed a significant negative correlation with rCBF, and %theta at P3, O1showed a significant negative correlation with rCMRO2. %Delta at P3, P4 and T5 was significantly negatively correlated with rCBF in the corresponding regions, and %alpha at almost all the electrodes (except O1, F3, P3) was significantly positively correlated with rCBF in the corresponding regions. %Delta and %alpha did not show any significant correlation with rCMRO2. (author)

  18. Determinants of renal tissue oxygenation as measured with BOLD-MRI in chronic kidney disease and hypertension in humans.

    OpenAIRE

    Pruijm, Menno; Hofmann, Lucie; Piskunowicz, Maciej; Muller, Marie-Eve; Zweiacker, Carole; Bassi, Isabelle; Vogt, Bruno; Stuber, Matthias; Burnier, Michel

    2014-01-01

    Experimentally renal tissue hypoxia appears to play an important role in the pathogenesis of chronic kidney disease (CKD) and arterial hypertension (AHT). In this study we measured renal tissue oxygenation and its determinants in humans using blood oxygenation level-dependent magnetic resonance imaging (BOLD-MRI) under standardized hydration conditions. Four coronal slices were selected, and a multi gradient echo sequence was used to acquire T2* weighted images. The mean cortical and medullar...

  19. Determinants of Renal Tissue Oxygenation as Measured with BOLD-MRI in Chronic Kidney Disease and Hypertension in Humans

    OpenAIRE

    Menno Pruijm; Lucie Hofmann; Maciej Piskunowicz; Marie-Eve Muller; Carole Zweiacker; Isabelle Bassi; Bruno Vogt; Matthias Stuber; Michel Burnier

    2014-01-01

    Experimentally renal tissue hypoxia appears to play an important role in the pathogenesis of chronic kidney disease (CKD) and arterial hypertension (AHT). In this study we measured renal tissue oxygenation and its determinants in humans using blood oxygenation level-dependent magnetic resonance imaging (BOLD-MRI) under standardized hydration conditions. Four coronal slices were selected, and a multi gradient echo sequence was used to acquire T2* weighted images. The mean cortical and medullar...

  20. Blood flow and oxygenation in peritendinous tissue and calf muscle during dynamic exercise in humans

    DEFF Research Database (Denmark)

    Boushel, R; Langberg, Henning; Green, Stefan Mathias; Skovgaard, D; Bulow, J; Kjaer, M

    1. Circulation around tendons may act as a shunt for muscle during exercise. The perfusion and oxygenation of Achilles' peritendinous tissue was measured in parallel with that of calf muscle during exercise to determine (1) whether blood flow is restricted in peritendinous tissue during exercise...... output by dye dilution, arterial pressure by an arterial catheter-transducer, and muscle and peritendinous O2 saturation by spatially resolved spectroscopy (SRS). 3. Calf blood flow rose 20-fold with exercise, reaching 44 +/- 7 ml (100 g)-1 min-1 (mean +/- s.e.m. ) at 9 W, while Achilles' peritendinous...... flow increased (7-fold) to 14 +/- 4 ml (100 g)-1 min-1, which was 18 % of the maximal flow established during reactive hyperaemia. SRS-O2 saturation fell both in muscle (from 66 +/- 2 % at rest to 57 +/- 3 %, P <0.05) and in peritendinous regions (58 +/- 4 to 52 +/- 4 %, P <0.05) during exercise along...

  1. Blood flow and oxygenation in peritendinous tissue and calf muscle during dynamic exercise in humans

    DEFF Research Database (Denmark)

    Boushel, Robert Christopher; Langberg, H; Green, Sara Marie Ehrenreich;

    2000-01-01

    1. Circulation around tendons may act as a shunt for muscle during exercise. The perfusion and oxygenation of Achilles' peritendinous tissue was measured in parallel with that of calf muscle during exercise to determine (1) whether blood flow is restricted in peritendinous tissue during exercise...... output by dye dilution, arterial pressure by an arterial catheter-transducer, and muscle and peritendinous O2 saturation by spatially resolved spectroscopy (SRS). 3. Calf blood flow rose 20-fold with exercise, reaching 44 +/- 7 ml (100 g)-1 min-1 (mean +/- s.e.m. ) at 9 W, while Achilles' peritendinous...... with a rise in leg vascular conductance and microvascular haemoglobin volume, despite elevated systemic vascular resistance. 4. The parallel rise in calf muscle and peritendinous blood flow and fall in O2 saturation during exercise indicate that blood flow is coupled to oxidative metabolism in both...

  2. Influence of mild hypothermia on vascular endothelial growth factor and infarct volume in brain tissues after cerebral ischemia in rats

    Institute of Scientific and Technical Information of China (English)

    Fei Ye; Gangming Xi; Biyong Qin; Shifeng Wang; Chengyan Li

    2006-01-01

    BACKGROUND: It has been demonstrated that mild hypothermia has obvious protective effect on both whole and local cerebral ischemia. However, the definite mechanism is still unclear for the brain protection of mild hypothermia on cerebral edema, inhibiting inflammatory reaction, stabilizing blood brain barrier, etc.OBJECTIVE: To investigate the effect of mild hypothermia on the expression of vascular endothelial growth factor and the infarct volume after cerebral ischemia in rats, and analyze the brain protective mechanism of mild hypothermia.DESIGN: A randomized grouping and controlled animal trial.SETTING: Department of Neurology, People's Hospital of Yunyang Medical College.MATERIALS: Twenty adult male SD rats of clean degree, weighing (250±30) g, were provided by the animal experimental center, School of Medicine, Wuhan University. The kits for SP immunohistochemistry were purchased from Beijing Zhongshan Golden Bridge Biotechnology Co., Ltd.METHODS: The experiments were carried out in the laboratory of Department of Neurology, Renmen Hospital of Wuhan University from May to July 2005. ① The 20 rats were divided randomly into normal temperature group (n =10) and mild hypothermia group (n =10). Models of permanent middle cerebral artery occlusion were established with modified nylon suture embolization. The rats were assessed with the Longa standards: O point for without nerve dysfunction; 1 for mild neurological deficit (fore claws could no extend completely); 2 for moderate neurological deficit (circling towards the affected side); 3 for severe neurological deficit (tilting towards the affected side); 4 for coma and unconscious; 1 -3 points represented that models were successfully established. The rats of the normal temperature group were fed at room temperature, and those in the mild hypothermia group were induced by hypothermia from 2 hours postoperatively, and the rectal temperature was kept at 34-35 ℃ for 72 hours. ② Measurement of infarct volume

  3. In vivo evidence of methamphetamine induced attenuation of brain tissue oxygenation as measured by EPR oximetry

    Energy Technology Data Exchange (ETDEWEB)

    Weaver, John, E-mail: jmweaver@salud.unm.edu [Center of Biomedical Research Excellence, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM 87131 (United States); Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM 87131 (United States); Yang, Yirong [Center of Biomedical Research Excellence, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM 87131 (United States); Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM 87131 (United States); Purvis, Rebecca [Center of Biomedical Research Excellence, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM 87131 (United States); Department of Neurology, University of New Mexico Health Sciences Center, Albuquerque, NM 87131 (United States); Weatherwax, Theodore [Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM 87131 (United States); Rosen, Gerald M. [Center for Biomedical Engineering and Technology, University of Maryland, Baltimore, MD 21201 (United States); Center for EPR Imaging In Vivo Physiology, University of Maryland, Baltimore, MD 21201 (United States); Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD 21201 (United States); Liu, Ke Jian [Center of Biomedical Research Excellence, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM 87131 (United States); Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM 87131 (United States); Department of Neurology, University of New Mexico Health Sciences Center, Albuquerque, NM 87131 (United States)

    2014-03-01

    Abuse of methamphetamine (METH) is a major and significant societal problem in the US, as a number of studies have suggested that METH is associated with increased cerebrovascular events, hemorrhage or vasospasm. Although cellular and molecular mechanisms involved in METH-induced toxicity are not completely understood, changes in brain O{sub 2} may play an important role and contribute to METH-induced neurotoxicity including dopaminergic receptor degradation. Given that O{sub 2} is the terminal electron acceptor for many enzymes that are important in brain function, the impact of METH on brain tissue pO{sub 2}in vivo remains largely uncharacterized. This study investigated striatal tissue pO{sub 2} changes in male C57BL/6 mice (16–20 g) following METH administration using EPR oximetry, a highly sensitive modality to measure pO{sub 2}in vivo, in situ and in real time. We demonstrate that 20 min after a single injection of METH (8 mg/kg i.v.), the striatal pO{sub 2} was reduced to 81% of the pretreatment level and exposure to METH for 3 consecutive days further attenuated striatal pO{sub 2} to 64%. More importantly, pO{sub 2} did not recover fully to control levels even 24 h after administration of a single dose of METH and continual exposure to METH exacerbates the condition. We also show a reduction in cerebral blood flow associated with a decreased brain pO{sub 2} indicating an ischemic condition. Our findings suggests that administration of METH can attenuate brain tissue pO{sub 2}, which may lead to hypoxic insult, thus a risk factor for METH-induced brain injury and the development of stroke in young adults. - Highlights: • Explored striatal tissue pO{sub 2}in vivo after METH administration by EPR oximetry. • pO{sub 2} was reduced by 81% after a single dose and 64% after 3 consecutive daily doses. • pO{sub 2} did not recover fully to control levels even 24 h after a single dose. • Decrease in brain tissue pO{sub 2} may be associated with a decrease in

  4. In vivo evidence of methamphetamine induced attenuation of brain tissue oxygenation as measured by EPR oximetry

    International Nuclear Information System (INIS)

    Abuse of methamphetamine (METH) is a major and significant societal problem in the US, as a number of studies have suggested that METH is associated with increased cerebrovascular events, hemorrhage or vasospasm. Although cellular and molecular mechanisms involved in METH-induced toxicity are not completely understood, changes in brain O2 may play an important role and contribute to METH-induced neurotoxicity including dopaminergic receptor degradation. Given that O2 is the terminal electron acceptor for many enzymes that are important in brain function, the impact of METH on brain tissue pO2in vivo remains largely uncharacterized. This study investigated striatal tissue pO2 changes in male C57BL/6 mice (16–20 g) following METH administration using EPR oximetry, a highly sensitive modality to measure pO2in vivo, in situ and in real time. We demonstrate that 20 min after a single injection of METH (8 mg/kg i.v.), the striatal pO2 was reduced to 81% of the pretreatment level and exposure to METH for 3 consecutive days further attenuated striatal pO2 to 64%. More importantly, pO2 did not recover fully to control levels even 24 h after administration of a single dose of METH and continual exposure to METH exacerbates the condition. We also show a reduction in cerebral blood flow associated with a decreased brain pO2 indicating an ischemic condition. Our findings suggests that administration of METH can attenuate brain tissue pO2, which may lead to hypoxic insult, thus a risk factor for METH-induced brain injury and the development of stroke in young adults. - Highlights: • Explored striatal tissue pO2in vivo after METH administration by EPR oximetry. • pO2 was reduced by 81% after a single dose and 64% after 3 consecutive daily doses. • pO2 did not recover fully to control levels even 24 h after a single dose. • Decrease in brain tissue pO2 may be associated with a decrease in CBF. • Administration of methamphetamine may lead to hypoxic insult

  5. Simultaneous measurement of cerebral and muscle tissue parameters during cardiac arrest and cardiopulmonary resuscitation

    Science.gov (United States)

    Nosrati, Reyhaneh; Ramadeen, Andrew; Hu, Xudong; Woldemichael, Ermias; Kim, Siwook; Dorian, Paul; Toronov, Vladislav

    2015-03-01

    In this series of animal experiments on resuscitation after cardiac arrest we had a unique opportunity to measure hyperspectral near-infrared spectroscopy (hNIRS) parameters directly on the brain dura, or on the brain through the intact pig skull, and simultaneously the muscle hNIRS parameters. Simultaneously the arterial blood pressure and carotid and femoral blood flow were recorded in real time using invasive sensors. We used a novel hyperspectral signalprocessing algorithm to extract time-dependent concentrations of water, hemoglobin, and redox state of cytochrome c oxidase during cardiac arrest and resuscitation. In addition in order to assess the validity of the non-invasive brain measurements the obtained results from the open brain was compared to the results acquired through the skull. The comparison of hNIRS data acquired on brain surface and through the adult pig skull shows that in both cases the hemoglobin and the redox state cytochrome c oxidase changed in similar ways in similar situations and in agreement with blood pressure and flow changes. The comparison of simultaneously measured brain and muscle changes showed expected differences. Overall the results show feasibility of transcranial hNIRS measurements cerebral parameters including the redox state of cytochrome oxidase in human cardiac arrest patients.

  6. Investigation of endocrine and immunological response in fat tissue to hyperbaric oxygen administration in rats.

    Science.gov (United States)

    Şen, H; Erbağ, G; Ovali, M A; Öztopuz, R Ö; Uzun, M

    2016-01-01

    Though HBO treatment is becoming more common, the mechanism of action is not fully known. The positive effects of HBO administration on the inflammatory response is thought to be a possible basic mechanism. As a result, we aimed to research whether endocrine and immunological response of fat tissue changes in rats given HBO treatment model. This research was carried out on Wistar albino rats, they were treated with hyperbaric oxygen therapy. Their fatty tissue were taken from the abdomen, gene expression of the cytokines and adipokines were analyzed with Real time PCR method. When the gene expression of hormones and cytokines by fat tissue was examined, the leptin, visfatin, TNF-α, IL-1β and IL-10 levels in the HBO treatment group were statistically significantly increased compared to the control group (p=0.0313, p=0.0156, p=0.0156, p=0.0156, p=0.0313). In conclusion, in our study we identified that HBO administration affected the endochrinological functions of fat tissue. PMID:27188864

  7. Stable hydrogen, oxygen and sulfur isotopes composition in different tissues of cattle

    International Nuclear Information System (INIS)

    In order to research on stable hydrogen, oxygen, sulfur isotopes composition in different tissues of cattle, as well as the breed, δ 2H and δ 34S values of different defatted muscle, cattle tail hair, blood, liver, also δ 2h and δ 18O values of water from muscle were determined by isotope ratio mass spectrometry. The stable sulfur isotope composition was not affected by cattle variety, meanwhile the hydrogen was uncertain; the δ 2H and δ 34S values between different defatted muscle, blood, liver, cattle hair were significantly different, at the same time the δ 34S and δ 2H values between each tissue were not significantly correlated; the δ 2H values were strongly correlated with the δ 18O values of muscle water. The above results indicated that stable sulfur and hydrogen isotopes fractionation in the various tissues were discrepant, thus the proper tissue should be selected according to the purpose and object in the beef traceability. (authors)

  8. Association of serum reactive oxygen metabolite levels with normal tissue damages by carbon-ion radiotherapy

    International Nuclear Information System (INIS)

    Oxygen is required for respiration and the energetic processes that enable aerobic life. Free radical and reactive oxygen metabolite (ROM) formations create oxidative stress and contribute to various processes including aging, degenerative diseases and cancer. Additionally, they may have a role in the radiotherapy for various types of cancer. In this study, we aimed to investigate the degree of oxidative stress for carbon-ion radiotherapy in locally recurrent rectal cancer and pancreas cancer, and to find out whether the degree of oxidative stress shows any difference among different grade of normal tissue damages. It can be used as an index for their differential diagnosis. Sixteen patients with locally recurrent rectal cancer and 6 pancreas cancers were included in the study. The BAP levels were lower before carbon-ion treatment than after treatment. The ROM levels were significantly lower before treatment than after treatment. It might be possible to conclude that the serum BAP and ROM levels may be an index parameter for normal tissue damages. (author)

  9. Nanoparticle-enhanced spectral photoacoustic tomography: effect of oxygen saturation and tissue heterogeneity

    Science.gov (United States)

    Vogt, William C.; Jia, Congxian; Wear, Keith A.; Garra, Brian S.; Pfefer, T. Joshua

    2016-03-01

    Molecular imaging for breast cancer detection, infectious disease diagnostics and preclinical animal research may be achievable through combined use of targeted exogenous agents - such as nanoparticles - and spectral Photoacoustic Tomography (PAT). However, tissue heterogeneity can alter fluence distributions and acoustic propagation, corrupting measured PAT absorption spectra and complicating in vivo nanoparticle detection and quantitation. Highly absorptive vascular structures represent a common confounding factor, and variations in vessel hemoglobin saturation (SO2) may alter spectral content of signals from adjacent/deeper regions. To evaluate the impact of this effect on PAT nanoparticle detectability, we constructed heterogeneous phantoms with well-characterized channel-inclusion geometries and biologically relevant optical and acoustic properties. Phantoms contained an array of tubes at several depths filled with hemoglobin solutions doped with varying concentrations of gold nanorods with an absorption peak at 780 nm. Both overlying and target network SO2 was tuned using sodium dithionite. Phantoms were imaged from 700 to 900 nm using a custom PAT system comprised of a tunable pulsed laser and a research-grade ultrasound system. Recovered nanoparticle spectra were analyzed and compared with results from both spectrophotometry and PAT data from waterimmersed tubes containing blood and nanoparticle solutions. Results suggested that nanoparticle selection for a given PAT application should take into account expected oxygenation states of both target blood vessel and background tissue oxygenation to achieve optimal performance.

  10. Red blood cell (RBC) deformability, RBC aggregability and tissue oxygenation in hypertension.

    Science.gov (United States)

    Cicco, G; Pirrelli, A

    1999-01-01

    Arterial hypertension could be considered a progressive ischaemic syndrome interesting the macro and the microcirculation. In order to improve the clinical and therapeutic approach to the treatment of arterial hypertension, research has centered on blood flow to evaluate the different components and their very intricate relationships influencing the micro- and the macrocirculation. Of course the main problem is to study the link between the blood flow and the peripheral tissue oxygenation. During hypertension very important alterations in rheological, mechanical and biochemical characteristics of erythrocytes and of blood flow have been shown. It is very relevant the increase in blood viscosity, the decrease in red blood cell (RBC) deformability, the formation of RBC "rouleaux" and RBC aggregates. These hemorheological determinants can favour an increase of peripheral resistances and of arterial blood pressure, causing or worsening hypertension, a decrease in oxygen transport to tissue and peripheral perfusion, a decrease of the active exchange surface area in the microvasculature, especially in complicated hypertension. We have studied 320 patients: 123 with Essential Hypertension (EH) (M 59, F 64 aged 50 +/- 25 years); 81 with Secondary Hypertension (SH) without associated other pathologies influencing hemorheology (M 42, F 39 aged 48 +/- 20 years); 116 SH with other pathologies or conditions associated influencing hemorheology such as: diabetes, lipoidoproteinosis, obesity, smoking, HD, elderly, etc. (M 48, F 68 aged 46 +/- 20 years). Using a Laser-assisted Optical Rotational Red Cell Analyzer (LORCA) acc. to Hardeman (1994) we studied Elongation Index (EI) and aggregation kinetics of red blood cells in these patients. We also evaluated TcpO2 and TcpCO2 using a transcutaneous oxymeter (Microgas 7650, Kontron Instruments). In hypertensives we found a decrease in erythrocyte deformability (evaluated with EI), in erythrocyte aggregation time, a fibrinogenaemia

  11. Neuroprotective effect of high-dose hyperbaric oxygenation on rats with acute cerebral infarction in super-early stage Curative comparison between 9-hour and 18-hour therapeutic protocols

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    BACKGROUND: Previously, only single short-time low-dose hyperbaric oxygenation (HBO) protocol was administrated to treat acute ischemic stroke in early stage and the conflicting results were obtained. There are few studies to report the outcome of administering long-time (can cover all the natural pathologic progression period) high-dose HBO to treat the disease.OBJECTIVE: To evaluate the therapeutic effect between two kinds of high-dose hyperbaric oxygenation on super-early stage of acute permanent middle cerebral artery occlusion (MCAO) in rats.DESIGN: A randomized controlled experimental study.SETTING: Beijing Tiantan Hospital, Capital Medical University; Beijing Research Institute of Neurosurgery.MATERIALS: Seventy-four male SD rats, aged 2.5 months old, weighing (280±20) g, were provided by the Animal Institute, Chinese Academy of Medical Sciences. Hyperbaric oxygenation device was hyperbaric air cabin in which there was a self-made pure oxygen animal experimental cabin (made in China).METHODS: This experiment was carried out in the municipal laboratory of Beijing Tiantan Hospital affiliated to Capital Medical University and Beijing Research Institute of Neurosurgery. ① Experimental intervention: All the rats were developed into models of permanent MCAO by suture embolism. Then, they were randomly divided into two HBO groups (9hours and 18 hours) and control group, with 24 rats in each as well as 3-hour ultrastructure control group, with 2 rats. After being modeled for 3 hours, rats in the two HBO groups stayed in the hyperbaric cabin for 9 hours and 18 hours,separately. Rats in the 9-hour HBO group inhaled pure oxygen at hours 1, 3, 5, 7 and 9, and hyperbaric air at hours 2, 4, 6 and 8. Rats in the 18-hour HBO group inhaled pure oxygen at hours 1, 3, 5, 7, 9, 11, 13, 15 and 17, and hyperbaric air at hours 2, 4, 6, 8, 10 12, 14, 16 and 18. After being created into models, rats in the control group and 3-hour ultrastructure control group breathed room air.

  12. Effects of the Oxygen-Carrying Solution OxyVita C on the Cerebral Microcirculation and Systemic Blood Pressures in Healthy Rats

    Directory of Open Access Journals (Sweden)

    Rania Abutarboush

    2014-11-01

    Full Text Available The use of hemoglobin-based oxygen carriers (HBOC as oxygen delivering therapies during hypoxic states has been hindered by vasoconstrictive side effects caused by depletion of nitric oxide (NO. OxyVita C is a promising oxygen-carrying solution that consists of a zero-linked hemoglobin polymer with a high molecular weight (~17 MDa. The large molecular weight is believed to prevent extravasation and limit NO scavenging and vasoconstriction. The aim of this study was to assess vasoactive effects of OxyVita C on systemic blood pressures and cerebral pial arteriole diameters. Anesthetized healthy rats received four intravenous (IV infusions of an increasing dose of OxyVita C (2, 25, 50, 100 mg/kg and hemodynamic parameters and pial arteriolar diameters were measured pre- and post-infusion. Normal saline was used as a volume-matched control. Systemic blood pressures increased (P ≤ 0.05 with increasing doses of OxyVita C, but not with saline. There was no vasoconstriction in small (<50 µm and medium-sized (50–100 µm pial arterioles in the OxyVita C group. In contrast, small and medium-sized pial arterioles vasoconstricted in the control group. Compared to saline, OxyVita C showed no cerebral vasoconstriction after any of the four doses evaluated in this rat model despite increases in blood pressure.

  13. Effect of oxygen and heliox breathing on air bubbles in adipose tissue during 25-kPa altitude exposures

    DEFF Research Database (Denmark)

    Randsoe, T.; Kvist, T.M.; Hyldegaard, O.

    2008-01-01

    .7) after which they started shrinking or remained stable throughout the observation period. Bubble growth time was significantly longer during oxygen breathing compared with heliox breathing and preoxygenated animals. Significantly more bubbles disappeared in preoxygenated animals compared with oxygen and......At altitude, bubbles are known to form and grow in blood and tissues causing altitude decompression sickness. Previous reports indicate that treatment of decompression sickness by means of oxygen breathing at altitude may cause unwanted bubble growth. In this report we visually followed the in vivo...... changes of micro air bubbles injected into adipose tissue of anesthetized rats at 101.3 kPa (sea level) after which they were decompressed from 101.3 kPa to and held at 25 kPa (10,350 m), during breathing of oxygen or a heliox(34:66) mixture (34% helium and 66% oxygen). Furthermore, bubbles were studied...

  14. Validation of NIRS in measuring tissue hemoglobin concentration and oxygen saturation on ex vivo and isolated limb models

    Science.gov (United States)

    Xu, Xiaorong; Zhu, Wen; Padival, Vikram; Xia, Mengna; Cheng, Xuefeng; Bush, Robin; Christenson, Linda; Chan, Tim; Doherty, Tim; Iatridis, Angelo

    2003-07-01

    Photonify"s tissue spectrometer uses Near-Infrared Spectroscopy for real-time, noninvasive measurement of hemoglobin concentration and oxygen saturation [SO2] of biological tissues. The technology was validated by a series of ex vivo and animal studies. In the ex vivo experiment, a close loop blood circulation system was built, precisely controlling the oxygen saturation and the hemoglobin concentration of a liquid phantom. Photonify"s tissue spectrometer was placed on the surface of the liquid phantom for real time measurement and compared with a gas analyzer, considered the gold standard to measure oxygen saturation and hemoglobin concentration. In the animal experiment, the right hind limb of each dog accepted onto the study was surgically removed. The limb was kept viable by connecting the femoral vein and artery to a blood-primed extracorporeal circuit. Different concentrations of hemoglobin were obtained by adding designated amount of saline solution into the perfusion circuit. Photonify"s tissue spectrometers measured oxygen saturation and hemoglobin concentration at various locations on the limb and compared with gas analyzer results. The test results demonstrated that Photonify"s tissue spectrometers were able to detect the relative changes in tissue oxygen saturation and hemoglobin concentration with a high linear correlation compared to the gas analyzer

  15. Intramuscular pressure, tissue oxygenation and EMG fatigue measured during isometric fatigue-inducing contraction of the multifidus muscle

    OpenAIRE

    Kramer, M.; Dehner, C; Hartwig, E; Völker, H. U.; Sterk, J; Elbel, M.; Weikert, E.; Gerngroß, H; Kinzl, L.; Willy, C

    2005-01-01

    Simultaneous measurement of intramuscular pressure (IMP), tissue oxygen partial pressure (pO2) and EMG fatigue parameters in the multifidus muscle during a fatigue-inducing sustained muscular contraction. The study investigated the following hypotheses: (1) Increases in IMP result in tissue hypoxia; (2) Tissue hypoxia is responsible for loss of function in the musculature. The nutrient supply to muscle during muscle contraction is still not fully understood. It is assumed that muscle contract...

  16. Effects of Electroacupuncture plus Intra-carotid Drug Injection on Rheoencephalogram in Patients with Cerebral Infarction

    Institute of Scientific and Technical Information of China (English)

    李江明; 胡永均; 童利民; 王大军; 张道敬

    2004-01-01

    Purpose: To investigate the mechanism of electroacupuncture (EA) plus intra-carotid drug injection for treating cerebral infarction. Methods: Rheoencephalogram was recorded with a RG-2B type of bridge rheoencephalograph and findings were compared before and after the treatment. Results: After the treatment, the prolonged rising time was shortened, and the decreased amplitude obviously elevated. Conclusion: The therapy can dilate cerebral blood vessels, increase the cerebral blood flow, and improve the elasticity of cerebral blood vessels, leading to sufficient blood and oxygen supply in the ischemic brain tissues and to restoration of their functions.

  17. Multisite Tissue Oxygenation Monitoring Indicates Organ-Specific Flow Distribution and Oxygen Delivery Related to Low Cardiac Output in Preterm Infants With Clinical Sepsis

    NARCIS (Netherlands)

    van der Laan, Michelle E; Roofthooft, Marc; Fries, Marian W A; Schat, Trijntje E; Bos, Arend F; Berger, Rolf M F; Kooi, Elisabeth M W

    2016-01-01

    OBJECTIVES: Cardiac output may be compromised in preterm infants with sepsis. Whether low cardiac output is associated with low tissue oxygen supply in these patients is unclear. The aim of the current study was to assess the association between cardiac output, assessed by echocardiography, and tiss

  18. Alterations in deoxyribonucleic acid and proteins in cerebral tissues from fetuses subject to alcohol in utero

    OpenAIRE

    Lopez-de-Ochoa, J.A.F. (J.A.F.); Villa-Elizaga, I. (Ignacio); Frizell, E. (E.); Fresnillo, M. (M.); Ballesteros, A.; Olazabal, A. (A.); Sierrasesumaga, L. (Luis)

    1989-01-01

    Critical period for intra-uterine growth retardation (IUGR), and biochemical parameters for tissue growth were studied in an animal model of Fetal Alcohol Syndrome (FAS) in rats. Our research used 40 animals, fed Lieber and DeCarli liquid diets, distributed into 4 groups: C, or control--non-alcoholic--, ad libitum; E, or alcoholic, fed ad libitum; F, or alcoholic, pair fed to E; and P, non-alcoholic, pair fed to E and F. Fetuses of group E were exposed to ethanol during the organogenic period...

  19. Effect of oxygen breathing and perfluorocarbon emulsion treatment on air bubbles in adipose tissue during decompression sickness

    DEFF Research Database (Denmark)

    Randsoe, T; Hyldegaard, O

    2009-01-01

    Decompression sickness (DCS) after air diving has been treated with success by means of combined normobaric oxygen breathing and intravascular perfluorocarbon (PFC) emulsions causing increased survival rate and faster bubble clearance from the intravascular compartment. The beneficial PFC effect...... breathing. The combined effect of oxygen breathing and PFC infusion neither prevented nor increased transient bubble growth time, rate, or growth ratio compared with oxygen breathing alone. We conclude that oxygen breathing in combination with PFC infusion causes faster bubble disappearance and does...... has been explained by the increased transport capacity of oxygen and inert gases in blood. However, previous reports have shown that extravascular bubbles in lipid tissue of rats suffering from DCS will initially grow during oxygen breathing at normobaric conditions. We hypothesize that the combined...

  20. Cerebral Metabolic Profiling of Hypothermic Circulatory Arrest with and Without Antegrade Selective Cerebral Perfusion: Evidence from Nontargeted Tissue Metabolomics in a Rabbit Model

    Science.gov (United States)

    Zou, Li-Hua; Liu, Jin-Ping; Zhang, Hao; Wu, Shu-Bin; Ji, Bing-Yang

    2016-01-01

    Background: Antegrade selective cerebral perfusion (ASCP) is regarded to perform cerebral protection during the thoracic aorta surgery as an adjunctive technique to deep hypothermic circulatory arrest (DHCA). However, brain metabolism profile after ASCP has not been systematically investigated by metabolomics technology. Methods: To clarify the metabolomics profiling of ASCP, 12 New Zealand white rabbits were randomly assigned into 60 min DHCA with (DHCA+ASCP [DA] group, n = 6) and without (DHCA [D] group, n = 6) ASCP according to the random number table. ASCP was conducted by cannulation on the right subclavian artery and cross-clamping of the innominate artery. Rabbits were sacrificed 60 min after weaning off cardiopulmonary bypass. The metabolic features of the cerebral cortex were analyzed by a nontargeted metabolic profiling strategy based on gas chromatography-mass spectrometry. Variable importance projection values exceeding 1.0 were selected as potentially changed metabolites, and then Student's t-test was applied to test for statistical significance between the two groups. Results: Metabolic profiling of brain was distinctive significantly between the two groups (Q2Y = 0.88 for partial least squares-DA model). In comparing to group D, 62 definable metabolites were varied significantly after ASCP, which were mainly related to amino acid metabolism, carbohydrate metabolism, and lipid metabolism. Kyoto Encyclopedia of Genes and Genomes analysis revealed that metabolic pathways after DHCA with ASCP were mainly involved in the activated glycolytic pathway, subdued anaerobic metabolism, and oxidative stress. In addition, L-kynurenine (P = 0.0019), 5-methoxyindole-3-acetic acid (P = 0.0499), and 5-hydroxyindole-3-acetic acid (P = 0.0495) in tryptophan metabolism pathways were decreased, and citrulline (P = 0.0158) in urea cycle was increased in group DA comparing to group D. Conclusions: The present study applied metabolomics analysis to identify the cerebral

  1. Non-invasive, simultaneous quantification of vascular oxygenation and glucose uptake in tissue.

    Directory of Open Access Journals (Sweden)

    Narasimhan Rajaram

    Full Text Available We report the development of non-invasive, fiber-based diffuse optical spectroscopy for simultaneously quantifying vascular oxygenation (SO2 and glucose uptake in solid tumors in vivo. Glucose uptake was measured using a fluorescent glucose analog, 2-[N-(7-nitrobenz-2-oxa-1,3-diaxol-4-ylamino]-2-deoxyglucose (2-NBDG. Quantification of label-free SO2 and 2-NBDG-fluorescence-based glucose uptake 60 minutes after administration of the tracer (2-NBDG60 was performed using computational models of light-tissue interaction. This study was carried out on normal tissue and 4T1 and 4T07 murine mammary tumor xenografts in vivo. Injection of 2-NBDG did not cause a significant change in optical measurements of SO2, demonstrating its suitability as a functional reporter of tumor glucose uptake. Correction of measured 2-NBDG-fluorescence for the effects of absorption and scattering significantly improved contrast between tumor and normal tissue. The 4T1 and 4T07 tumors showed significantly decreased SO2, and 4T1 tumors demonstrated increased 2-NBDG60 compared with normal tissue (60 minutes after the administration of 2-NBDG when perfusion-mediated effects have cleared. 2-NBDG-fluorescence was found to be highly sensitive to food deprivation-induced reduction in blood glucose levels, demonstrating that this endpoint is indeed sensitive to glycolytic demand. 2-NBDG60 was also found to be linearly related to dose, underscoring the importance of calibrating for dose when comparing across animals or experiments. 4T1 tumors demonstrated an inverse relationship between 2-NBDG60 and SO2 that was consistent with the Pasteur effect, particularly when exposed to hypoxic gas breathing. Our results illustrate the potential of optical spectroscopy to provide valuable information about the metabolic status of tumors, with important implications for cancer prognosis.

  2. Exploration study on nursing care in hyperbaric oxygen treatment for cerebral infarction%高压氧治疗脑梗塞的护理探讨

    Institute of Scientific and Technical Information of China (English)

    叶秋燕; 陈冬梅; 刘涛; 伍柳丝; 伍爱芳; 冯散香

    2013-01-01

    目的 观察高压氧治疗对脑梗塞患者的疗效及相关护理措施.方法 随机将120例脑梗塞患者分成实验组和对照组,实验组行高压氧治疗并进行观察,治疗方案:压力0.20 MPa,吸纯氧80min,中间休息10 min,改吸空气,12d为1个疗程.结果 高压氧治疗组基本痊愈率、显效率、有效率分别为93%、93%、100%;对照组有效率为78%,两组比较P<0.01,差异有显著性.结论 高压氧对脑梗塞的治疗有助于提高疗效,促进机体整体功能的恢复,减少后遗症的发生率,减少致残率,明显提高了患者的生命质量和生活质量.%Objective To observe the efficacy of hyperbaric oxygen therapy on patients with cerebral infarction and explore related care measures.Methods Randomized 120 patients with cerebral infarction were divided into experimental and control groups,the experimental group used hyperbaric oxygen therapy and observation,treatment options: pressure 0.20 MPa,inhaling pure oxygen 80 min break of 10 min changed breathing air,12 d as a course of treatment.Results The cure rate of hyperbaric oxygen therapy group were markedly effective,93%,93%,and 100% respectively; effective rate of 78% in the control group,the differences of two groups were statistically significant (P<O.OI).Conclusion Hyperbaric oxygen treatment of cerebral infarction helps to improve efficacy.promote the recovery of the overall function of the body,and reduce the incidence of complications and morbidity,and significantly improve the patients' quality of life.

  3. Even mild respiratory distress alters tissue oxygenation significantly in preterm infants during neonatal transition

    International Nuclear Information System (INIS)

    Near-infrared spectroscopy (NIRS) enables continuous non-invasive measurements of regional oxygen saturation (rSO2). The aim was to evaluate the dynamics of rSO2 of the brain, preductal and postductal tissues during postnatal transition in preterm infants with and without respiratory support (RS). This single-centre study was designed as an exploratory prospective observational study. Fifty one preterm infants (≥ 30 + 0 and < 37 + 0 weeks) delivered by caesarean section were included. RS using a T-Piece-Resuscitator and supplemental oxygen were given according to guidelines. NIRS measurements were carried out by using Invos Monitor (Covidien; USA) for the first 15 min of life. Three NIRS transducers were attached on the forehead (rSO2brain), the right forearm (rSO2arm) and the left lower leg (rSO2leg). Two groups were compared based on need for RS: normal transition (NT) and RS group. Results: In NT group rSO2brain increased over time and was significantly higher than rSO2arm, whereas in RS group rSO2brain and rSO2arm increased without significant differences. Courses of rSO2arm and rSO2leg increased over time and showed a converging pattern with initially lower values of rSO2leg in NT group and a diverging pattern with lower levels of rSO2leg in RS group. Overall, rSO2 levels were higher in NT compared to RS group. Conclusion: Our findings indicate that the decreased rSO2 levels in RS group compared to NT group are not only caused by lower arterial oxygen saturation levels, but also by a compromised perfusion even in infants with only mild respiratory distress. (paper)

  4. Modelling of the Effect of End-Tidal Carbon Dioxide on Cerebral Oxygen Saturation in Beach Chair Position under General Anaesthesia.

    Science.gov (United States)

    Kim, So Yeon; Chae, Dong Woo; Chun, Yong-Min; Jeong, Kyu Hee; Park, Kyungsoo; Han, Dong Woo

    2016-07-01

    Patients undergoing shoulder surgery in the beach chair position (BCP) under general anaesthesia may be at risk of cerebral desaturation. Increasing end-tidal carbon dioxide (EtCO2 ) is the most convenient and powerful method for the management of cerebral desaturation. The purpose of this study was to investigate the quantitative relationship between EtCO2 and cerebral oxygen saturation (rSO2 ) and to identify the associated influencing factors. Fifty-one patients undergoing arthroscopic shoulder surgery in the BCP under general anaesthesia completed this study. Desflurane and remifentanil were used, and EtCO2 was steadily increased and then decreased by adjusting the ventilator settings every 3 min. so that time lag of rSO2 response to EtCO2 changes could be delineated. Near-infrared spectroscopy was used to monitor rSO2 response. An indirect response model was used to examine the relationship between EtCO2 and rSO2 . To determine the relevant covariates, a stepwise approach was used. There was a linear relationship between rSO2 and EtCO2 with a slight delay in the peak of rSO2 relative to EtCO2 . Increase in end-tidal desflurane concentration led to a slower response of rSO2 to the changes of EtCO2 (p = 0.0002). The presence of diabetes mellitus reduced the reactivity of rSO2 to EtCO2 changes (p < 0.0001). This model-based approach revealed that diabetes mellitus attenuates the response of rSO2 to changes in EtCO2 . The management of cerebral desaturation by hypercapnia in patients with diabetes may be less effective than in non-diabetic patients under general anaesthesia with BCP. PMID:26707006

  5. A pilot study of a new spectrophotometry device to measure tissue oxygen saturation

    International Nuclear Information System (INIS)

    Tissue oxygen saturation (SO2) measurements have the potential for far wider use than at present but are limited by device availability and portability for many potential applications. A device based on a small, low-cost general-purpose spectrophotometer (the Harrison device) might facilitate wider use. The aim of this study was to compare the Harrison device with a commercial instrument, the LEA O2C. Measurements were carried out on the forearm and finger of 20 healthy volunteers, using a blood pressure cuff on the upper arm to induce different levels of oxygenation. Repeatability of both devices was assessed, and the Bland–Altman method was used to assess agreement between them. The devices showed agreement in overall tracking of changes in SO2. Test–retest agreement for the Harrison device was worse than for O2C, with SD repeatability of 10.6% (forearm) or 18.6% (finger). There was no overall bias between devices, but mean (SD) difference of 1.2 (11.8%) (forearm) or 4.4 (11.5%) (finger) were outside of a clinically acceptable range. Disagreements were attributed to the stability of the Harrison probe and the natural SO2 variations across the skin surface increasing the random error. Therefore, though not equivalent to the LEA O2C, a probe redesign and averaged measurements may help establish the Harrison device as a low cost alternative. (paper)

  6. Intermittent high oxygen influences the formation of neural retinal tissue from human embryonic stem cells.

    Science.gov (United States)

    Gao, Lixiong; Chen, Xi; Zeng, Yuxiao; Li, Qiyou; Zou, Ting; Chen, Siyu; Wu, Qian; Fu, Caiyun; Xu, Haiwei; Yin, Zheng Qin

    2016-01-01

    The vertebrate retina is a highly multilayered nervous tissue with a large diversity of cellular components. With the development of stem cell technologies, human retinas can be generated in three-dimensional (3-D) culture in vitro. However, understanding the factors modulating key productive processes and the way that they influence development are far from clear. Oxygen, as the most essential element participating in metabolism, is a critical factor regulating organic development. In this study, using 3-D culture of human stem cells, we examined the effect of intermittent high oxygen treatment (40% O2) on the formation and cellular behavior of neural retinas (NR) in the embryonic body (EB). The volume of EB and number of proliferating cells increased significantly under 40% O2 on day 38, 50, and 62. Additionally, the ratio of PAX6+ cells within NR was significantly increased. The neural rosettes could only develop with correct apical-basal polarity under 40% O2. In addition, the generation, migration and maturation of retinal ganglion cells were enhanced under 40% O2. All of these results illustrated that 40% O2 strengthened the formation of NR in EB with characteristics similar to the in vivo state, suggesting that the hyperoxic state facilitated the retinal development in vitro. PMID:27435522

  7. Repetitive Transcranial Magnetic Stimulation Changes Cerebral Oxygenation on the Left Dorsolateral Prefrontal Cortex in Bulimia Nervosa: A Near-Infrared Spectroscopy Pilot Study.

    Science.gov (United States)

    Sutoh, Chihiro; Koga, Yasuko; Kimura, Hiroshi; Kanahara, Nobuhisa; Numata, Noriko; Hirano, Yoshiyuki; Matsuzawa, Daisuke; Iyo, Masaomi; Nakazato, Michiko; Shimizu, Eiji

    2016-01-01

    Previous studies showed that food craving in eating disorders can be weakened with high-frequency repetitive transcranial magnetic stimulation (rTMS) on the left dorsolateral prefrontal cortex (DLPFC). The aims of this study were to assess cerebral oxygenation change induced with rTMS and to assess the short-term impact of rTMS on food craving and other bulimic symptoms in patients with bulimia nervosa (BN). Eight women diagnosed with BN according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision criteria participated in this study. We measured haemoglobin concentration changes in the DLPFC with near-infrared spectroscopy during cognitive tasks measuring self-regulatory control in response to food photo stimuli, both at baseline and after a single session of rTMS. Subjective ratings for food cravings demonstrated significant reduction. A significant decrease in cerebral oxygenation of the left DLPFC was also observed after a single session of rTMS. Measurement with NIRS after rTMS intervention may be applicable for discussing the mechanisms underlying rTMS modulation in patients with BN. PMID:26481583

  8. Near-infrared spectroscopy for monitoring of tissue oxygenation of exercising skeletal muscle in a chronic compartment syndrome model

    Science.gov (United States)

    Breit, G. A.; Gross, J. H.; Watenpaugh, D. E.; Chance, B.; Hargens, A. R.

    1997-01-01

    Variations in the levels of muscle hemoglobin and of myoglobin oxygen saturation can be detected non-invasively with near-infrared spectroscopy. This technique could be applied to the diagnosis of chronic compartment syndrome, in which invasive testing has shown increased intramuscular pressure associated with ischemia and pain during exercise. We simulated chronic compartment syndrome in ten healthy subjects (seven men and three women) by applying external compression, through a wide inflatable cuff, to increase the intramuscular pressure in the anterior compartment of the leg. The tissue oxygenation of the tibialis anterior muscle was measured with near-infrared spectroscopy during gradual inflation of the cuff to a pressure of forty millimeters of mercury (5.33 kilopascals) during fourteen minutes of cyclic isokinetic dorsiflexion and plantar flexion of the ankle. The subjects exercised with and without external compression. The data on tissue oxygenation for each subject then were normalized to a scale of 100 per cent (the baseline value, or the value at rest) to 0 per cent (the physiological minimum, or the level of oxygenation achieved by exercise to exhaustion during arterial occlusion of the lower extremity). With external compression, tissue oxygenation declined at a rate of 1.4 +/- 0.3 per cent per minute (mean and standard error) during exercise. After an initial decrease at the onset, tissue oxygenation did not decline during exercise without compression. The recovery of tissue oxygenation after exercise was twice as slow with compression (2.5 +/- 0.6 minutes) than it was without the use of compression (1.3 +/- 0.2 minutes).

  9. Simultaneous measurement of cerebral blood flow and oxygen extraction fraction by positron emission tomography: theoretical study and experimental evidence of cerebral blood flow measurement with the C15O2 continuous inhalation technique

    International Nuclear Information System (INIS)

    The method of the continuous inhalation technique of oxygen-15 labelled CO2 coupled with positron emission tomography for the measurement of cerebral blood flow (C.B.F.) is described. An indirect experimental verification that this technique allowed the measurement of C.B.F. has been carried out in baboons by showing the expected change in the measured parameter with variations in the PaCO2. A critical investigation of the C15O2 model was performed. The amount of tracer present in the cerebral vascular pool has a negligible effect on C.B.F. value. The use of a mean brain-blood partition coefficient of water instead of that specific to gray or to white matter is commented upon, and its influence on the final C.B.F. value is studied. Lastly, the problem of the limited diffusion of water across the blood-brain-barrier is discussed. The study of the combined effects of gray-white mixing and limited wates extraction of the C.B.F. value shows that the C15O2 technique tends to understimate real C.B.F., and that this error is more severe with high flows and even gray white mixing. These limitations do not depart from the possibility to estimate in the same brain locus not only C.B.F. but oxygen utilization as well by the consecutive inhalation of C15O2 and 15O2. The advantages of this possibility has already been shown in a number of clinical studies

  10. Correlation between regional cerebral blood flow and degree of brain tissue injury of interictal epileptic activity in patients with epilepsy

    International Nuclear Information System (INIS)

    Objective: To explore the correlation between the change of regional cerebral blood flow (rCBF) and brain tissue injury from interictal epileptic activity in patients with epilepsy. Methods: Forty-eight patients with epilepsy and 30 healthy persons were included in the study from which the serum S100β protein levels were determined by double antibody sandwich ELISA method. SPECT rCBF imaging was performed in all patients. The visual and semi-quantitative analyses were used to analyze the epileptic foci. SPSS 11.0 was applied for variance and linear correlation analyses. Results: Serum S-100β in patients with interictal epileptic activity was significantly higher than that in control group ((0.572±0.163) μg/L vs (0.218±0.134) μg/L, t =9.96, P<0.01). According to epilepsy control criteria, 20 cases achieved complete control (CC), 18 cases achieved partial control (PR). However, 10 cases got no improvement,whose serum S-100β protein ((0.809±0.056) μg/L) and the percentage change of rCBF ((0.337±0.060) %) were significantly higher than those of CC ((0.443±0.083) μg/L, (0.035±0.038) %) and those of PC ((0.585±0.108) μg/L, (0.187±0.075)%), F=56. 740, 92. 316, P<0.01. There were high correlation between serum S-100β and the percentage change of rCBF in epilepsy patients (r =0.887, P<0.01). Conclusion: Serum S-100β protein assay combined with rCBF on SPECT imaging can make semi-quantitative diagnosis of epilepsy and help evaluate the brain damage from interictal epileptic activity. (authors)

  11. Investigating tissue respiration and skin microhaemocirculation under adaptive changes and the synchronization of blood flow and oxygen saturation rhythms

    International Nuclear Information System (INIS)

    Multi-functional laser non-invasive diagnostic systems allow the study of a number of microcirculatory parameters, including index of blood microcirculation (Im) (by laser Doppler flowmetry, LDF) and oxygen saturation (StO2) of skin tissue (by tissue reflectance oximetry, TRO). This research aimed to use such a system to investigate the synchronization of microvascular blood flow and oxygen saturation rhythms under normal and adaptive change conditions. Studies were conducted on eight healthy volunteers of 21–49 years. These volunteers were observed between one and six months, totalling 422 basic tests (3 min each). Measurements were performed on the palmar surface of the right middle finger and the lower forearm's medial surface. Rhythmic oscillations of LDF and TRO were studied using wavelet analysis. Combined tissue oxygen consumption data for all volunteers during ‘adaptive changes’ increased relative to normal conditions with and without arteriovenous anastomoses. Data analysis revealed resonance and synchronized rhythms in microvascular blood flow and oxygen saturation as an adaptive change in myogenic oscillation (vasomotion) resulting from exercise and possibly psychoemotional stress. Synchronization of myogenic rhythms during adaptive changes may lead to increased oxygen consumption as a result of increased microvascular blood flow velocity. (paper)

  12. Intracellular expression of reactive oxygen species-generating NADPH oxidase NOX4 in normal and cancer thyroid tissues

    NARCIS (Netherlands)

    U. Weyemi; B. Caillou; M. Talbot; R. Ameziane-El-Hassani; L. Lacroix; O. Lagent-Chevallier; A. Al Ghuzlan; D. Roos; J.M. Bidart; A. Virion; M. Schlumberger; C. Dupuy

    2010-01-01

    NADPH oxidase 4 (NOX4) belongs to the NOX family that generates reactive oxygen species (ROS). Function and tissue distribution of NOX4 have not yet been entirely clarified. To date, in the thyroid gland, only DUOX1/2 NOX systems have been described. NOX4 mRNA expression, as shown by real-time PCR,

  13. Simultaneous blood-tissue exchange of oxygen, carbon dioxide, bicarbonate, and hydrogen ion.

    Science.gov (United States)

    Dash, Ranjan K; Bassingthwaighte, James B

    2006-07-01

    A detailed nonlinear four-region (red blood cell, plasma, interstitial fluid, and parenchymal cell) axially distributed convection-diffusion-permeation-reaction-binding computational model is developed to study the simultaneous transport and exchange of oxygen (O2) and carbon dioxide (CO2) in the blood-tissue exchange system of the heart. Since the pH variation in blood and tissue influences the transport and exchange of O2 and CO2 (Bohr and Haldane effects), and since most CO2 is transported as HCO3(-) (bicarbonate) via the CO2 hydration (buffering) reaction, the transport and exchange of HCO3(-) and H+ are also simulated along with that of O2 and CO2. Furthermore, the model accounts for the competitive nonlinear binding of O2 and CO2 with the hemoglobin inside the red blood cells (nonlinear O2-CO2 interactions, Bohr and Haldane effects), and myoglobin-facilitated transport of O2 inside the parenchymal cells. The consumption of O2 through cytochrome-c oxidase reaction inside the parenchymal cells is based on Michaelis-Menten kinetics. The corresponding production of CO2 is determined by respiratory quotient (RQ), depending on the relative consumption of carbohydrate, protein, and fat. The model gives a physiologically realistic description of O2 transport and metabolism in the microcirculation of the heart. Furthermore, because model solutions for tracer transients and steady states can be computed highly efficiently, this model may be the preferred vehicle for routine data analysis where repetitive solutions and parameter optimization are required, as is the case in PET imaging for estimating myocardial O2 consumption. PMID:16775761

  14. Is dynamic cerebral autoregulation measurement using transcranial Doppler ultrasound reproducible in the presence of high concentration oxygen and carbon dioxide?

    Science.gov (United States)

    Minhas, Jatinder S; Syed, Nazia F; Haunton, Victoria J; Panerai, Ronney B; Robinson, Thompson G; Mistri, Amit K

    2016-05-01

    Reliability of cerebral blood flow velocity (CBFV) and dynamic cerebral autoregulation estimates (expressed as autoregulation index: ARI) using spontaneous fluctuations in blood pressure (BP) has been demonstrated. However, reliability during co-administration of O2 and CO2 is unknown. Bilateral CBFV (using transcranial Doppler), BP and RR interval recordings were performed in healthy volunteers (seven males, four females, age: 54  ±  10 years) on two occasions over 9  ±  4 d. Four 5 min recordings were made whilst breathing air (A), then 5%CO2 (C), 80%O2 (O) and mixed O2  +  CO2 (M), in random order. CBFV was recorded; ARI was calculated using transfer function analysis. Precision was quantified as within-visit standard error of measurement (SEM) and the coefficient of variation (CV). CBFV and ARI estimates with A (SEM: 3.85 & 0.87; CV: 7.5% & 17.8%, respectively) were comparable to a previous reproducibility study. The SEM and CV with C and O were similar, though higher values were noted with M; Bland-Altman plots indicated no significant bias across all gases for CBFV and ARI (bias  Doppler-ultrasound-estimated CBFV and ARI during inhalation of O2 and CO2 have acceptable levels of reproducibility and can be used to study the effect of these gases on cerebral haemodynamics. PMID:27093290

  15. The effects of anticholinergic drugs on regional cerebral blood flow, and oxygen metabolism in previously untreated patients with Parkinson`s disease

    Energy Technology Data Exchange (ETDEWEB)

    Obara, Satoko; Takahashi, Satoshi; Yonezawa, Hisashi; Sato, Yoshitomo [Iwate Medical Univ., Morioka (Japan). School of Medicine

    1998-12-01

    Regional cerebral blood flow (rCBF) and oxygen metabolism (rCMRO{sub 2}) were measured using the steady-state {sup 15}O technique and positron emission tomography (PET) in six previously untreated patients with Parkinson`s disease before and after trihexyphenidyl (THP) treatment. The patients comprised of 4 men and 2 women with Hoehn-Yahr stage II-III. Their ages at the onset of the study ranged from 46 to 57 years (mean{+-}SD, 51.8{+-}3.7) and the duration of the illness ranged from 10 to 48 months (mean{+-}SD, 28.8{+-}15.5). The PET study, assessments of the disability and cognitive function were undergone twice. The first time assessments were done was when the patients were not receiving any drugs, and the second time was one to three months after administration of 6 mg THP. All patients showed clinical improvement after THP treatment. The mean disability score of Unified Parkinson`s Disease Rating Scale decreased from 35.1 (SD{+-}11.3) to 25.7 (SD{+-}11.6). The cognitive function assessed by Hasegawa`s dementia rating scale-revised, Mini-Mental State Examination, Wechsler Adult Intelligence Scale-Revised, and Wechsler Memory Scale-Revised, were not significantly different before and after the THP treatment. After the THP treatment, rCBF and rCMRO{sub 2} decreased significantly in the striatum (about 15%) and all cerebral cortices (about 10%) on both sides contralateral and ipsilateral to the predominantly symptomatic limbs. We conclude that an anticholinergic THP decreases the rCBF and rCMRO{sub 2} significantly in the cerebral cortices without cognitive impairment in early untreated patients with Parkinson`s disease. (author)

  16. Nrf2/antioxidant defense pathway is involved in the neuroprotective effects of Sirt1 against focal cerebral ischemia in rats after hyperbaric oxygen preconditioning.

    Science.gov (United States)

    Xue, Fen; Huang, Jin-Wen; Ding, Pei-Yan; Zang, Hong-Gang; Kou, Zhi-Jian; Li, Ting; Fan, Juan; Peng, Zheng-Wu; Yan, Wen-Jun

    2016-08-01

    Sirtuin 1 (Sirt1) is a class III histone deacetylase involved in neuroprotection induced by hyperbaric oxygen preconditioning (HBO-PC) in animal models of ischemia. However, the underlying mechanisms remain to be illustrated. In the present study, rats exposed to middle cerebral artery occlusion (MCAO) were used to establish an ischemic stroke model. The infarct volume ratio, neurobehavioral score, and expressions of Sirt1, nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase 1 (HO-1), and superoxide dismutase 1 (SOD1) were evaluated at 7 days after reperfusion, and the level of malondialdehyde (MDA) was used to assess oxidative stress. HBO-PC increased the expression of Sirt1 and reduced infarct volume ratio and neurobehavioral deficit in MCAO rats. Meanwhile, HBO-PC also increased expression of Nrf2, HO-1, and SOD1 and decreased MDA content. Furthermore, either Sirt1 or Nrf2 knockdown by short interfering RNA (siRNA) inhibited the expression of Nrf2, HO-1, and SOD1 and eliminated the neuroprotective effects of HBO-PC. Taken together, the results suggest that the Nrf2/antioxidant defense pathway is involved in the long lasting neuroprotective effects of Sirt1 induced by HBO-PC against transient focal cerebral ischemia. PMID:27131779

  17. A new hemodynamic model shows that temporal perturbations of cerebral blood flow and metabolic rate of oxygen cannot be measured individually using functional near-infrared spectroscopy

    International Nuclear Information System (INIS)

    A recent dynamic model relates the functional near-infrared spectroscopy (fNIRS) measurements to hemodynamic and metabolic parameters. This note reports modified expressions of the new model in terms of cerebral blood volume (CBV), blood flow (CBF) and metabolic rate of oxygen (CMRO2). On the basis of these modified expressions, the new model reproduces known steady state relationships between hemoglobin concentration, CBF and CMRO2, and yields time-dependent relationships that describe transient changes. This new model allows for the translation of the fNIRS measurements into dynamic measures of ΔCBV/CBV0 and the difference ΔCBF/CBF0 – ΔCMRO2/CMRO2|0, provided that some baseline physiological parameters and a relationship between overall, arterial and venous blood volume changes are assumed. (note)

  18. Neuroprotective effects of the AMPA antagonist PNQX in oxygen-glucose deprivation in mouse hippocampal slice cultures and global cerebral ischemia in gerbils

    DEFF Research Database (Denmark)

    Montero, Maria; Nielsen, Marianne; Rønn, Lars Christian B;

    2007-01-01

    PNQX (9-methyl-amino-6-nitro-hexahydro-benzo(F)quinoxalinedione) is a selective AMPA antagonist with demonstrated neuroprotective effects in focal ischemia in rats. Here we report corresponding effects in mouse hippocampal slice cultures subjected to oxygen and glucose deprivation (OGD) and in....... For comparison, other cultures were exposed to the NMDA antagonist MK-801 using the same protocol. Both PNQX and MK-801 displayed significant neuroprotective effects in all hippocampal subfields when present during and after OGD. When added just after OGD, only PNQX retained some neuroprotective...... effect. When added 2 h after OGD neither PNQX nor MK-801 had an effect. Transient global cerebral ischemia was induced in Mongolian gerbils by occlusion of both common carotid arteries for 4.5 min, with PNQX (10 mg/kg) being injected i.p. 30, 60 and 90 min after the insult. Subsequent analysis of brain...

  19. 液体高压氧对急性脑卒中患者神经功能缺损恢复的作用%Observation on the effect of liquid hyperbaric oxygen therapy for acute cerebral infarction

    Institute of Scientific and Technical Information of China (English)

    杨金升; 王燕; 于伟玲; 罗晓红; 石莉

    2002-01-01

    @@ Background:Liquid hyperbaric oxygen therapy is a quickly developed therapy for acute cerebral infarction in recent years.It has characteristics of high safety,low toxicity,easy manipulation,especially good recovering effect on neurological deficit in acute stroke patients.We observed this effect in this paper.

  20. Care of Hyperbaric Oxygen in the Treatment of Patients with Acute Cerebral Infarction%急性脑梗死高压氧治疗的护理

    Institute of Scientific and Technical Information of China (English)

    刘艳洁; 李雪莲; 任秀国; 王静; 李超; 王丽茹

    2012-01-01

    本文总结了30 例高压氧治疗急性脑梗死患者过程中的护理要点.护理要点主要包括高压氧入舱前的护理、舱内的护理、出舱后的护理等.入舱前的护理主要包括对患者的常规护理及对病人的安全告知,并对患者进行心理护理及健康教育,使患者充分了解高压氧治疗前的一些注意事项.舱内的护理主要是定时与患者沟通,了解治疗过程中患者的感受与需求,以保证治疗的顺利进行.出舱后的护理包括协助患者出舱,告知患者出舱后的一些注意事项,如休息及饮食等,告知下次治疗的时间,并将患者安全送回病房.良好的护理能够提高高压氧治疗急性脑梗死的疗效.%This paper summarizes the nursing points of 30 cases of hyperbaric oxygen therapy of acute cerebral infarction . Nursing points include care before entering hyperbaric chamber, care in the hyperbaric chamber and care after hyperbaric oxygen therapy . Care before entering hyperbaric chamber includes the routine care safety inform to patients , psychological care and health education to patients , making the patients fully know about the notes before hyperbaric oxygen treatment. Care in the hyperbaric chamber is to communicate with patients , knowing about the feelings and needs of the patients during treatment for making sure the smooth progress of treatment . Care after hyperbaric oxygen therapy is to help patients* spacewalk . Informing some notes of the patients extravehicular , such as rest and diet , informing them the time of next treatment and safely transporting patients return to the wards . Therefore, the author thinks that good care can improve the efficacy of the patients with acute cerebral infarction which is worth to the application for the nurses .

  1. Prevention of radiation induced normal tissue damage by cytokines and hyperbaric oxygen

    International Nuclear Information System (INIS)

    Purpose/Objective: Radiation therapy (XRT) is an effective cancer treatment. A goal of therapy is minimization of side effects. Bone growth after XRT of children is one limiting normal tissue tolerance. The goal of the current experiment is to identify the possible protective effect of hyperbaric oxygen (HBO) and basic fibroblast growth factor (FGF) on bone growth after lower extremity radiation. Material and Methods: 170 five weeks old female C3H mice were divided into 17 study groups. Groups 1-4 are controls which received XRT at 0, 10, 20, and 30 Gy single fraction without subsequent HBO. Groups 5-7 had XRT at 10 Gy with HBO at weeks 1-4, weeks 5-8, and weeks 9-12 after XRT. Groups 8-10 had XRT at 20 Gy with HBO at weeks 1-4, weeks 5-8, and weeks 9-12 after XRT. Groups 11-13 had XRT at 30 Gy with HBO at weeks 1-4, weeks 5-8, and weeks 9-12 after XRT. Groups 14-17 had XRT at 30 Gy and iv FGF with or without HBO at weeks 1-4 (groups 14, 15), and at weeks 5-8 (groups 16, 17) after XRT. Using fluoroscopy, the animals were positioned so that the beam was directed to irradiate the entire right hindlimb, including the majority of the femur. Dosimetry was confirmed by TLD in mouse phantoms. HBO treatments were given 5 days per week for 4 weeks to each study group using 2 ATA (max. 15 PSI) of 100% oxygen for 3 hours/day. FGF was given intravenously at 6 μg twice a week for 4 weeks. X-ray films were taken to measure the leg (tibia and femur) length of animals before and 18 weeks after radiation. The acute and chronic side effects of skin in the irradiated area were checked daily according to standard criteria. The leg bones and soft tissue were collected at the end of experiment for histologic study. Result: HBO significantly reduces the retardation of bone growth induced by XRT for 10 and 20 Gy groups. For example, at the 18th week, leg length discrepancy is 0.0±1.6% for control, 4.2±1.3% for 10 Gy, and 8.2±1.8% for 20 Gy. HBO in 10 Gy groups decreased these

  2. Noninvasive Intracranial Pressure and Tissue Oxygen Measurements for Space and Earth

    Science.gov (United States)

    Hargens, A. R.; Ballard, R. E.; Murthy, G.; Watenpaugh, D. E.

    1994-01-01

    The paper discusses the following: Increasing intracranial pressure in humans during simulated microgravity. and near-infrared monitoring of model chronic compartment syndrome in exercising skeletal muscle. Compared to upright-seated posture, 0 deg. supine, 6 deg. HDT, and 15 deg. HDT produced TMD changes of 317 +/- 112, 403 +/- 114, and 474 +/- 112 n1 (means +/- S.E.), respectively. Furthermore, postural transitions from 0 deg. supine to 6 deg. HDT and from 6 deg. to 15 deg. HDT generated significant TMD changes (p less than 0.05). There was no hysteresis when postural transitions to HDT were compared to reciprocal transitions toward upright seated posture. Currently, diagnosis of chronic compartment syndrome (CCS) depends on measurement of intramuscular pressure by invasive catheterization. We hypothesized that this syndrome can be detected noninvasively by near-infrared (NIR) spectroscopy, which tracks variations in muscle hemoglobin/myoglobin oxygen saturation. CCS was simulated in the tibialis anterior muscle of 7 male and 3 female subjects by gradual inflation of a cuff placed around the leg to 40 mmHg during 14 minutes of cyclic isokinetic dorsiflexion exercise. On a separate day, subjects underwent the identical exercise protocol with no external compression. In both cases, tissue oxygenation (T(sub O2) was measured in the tibialis anterior by NIR spectroscopy and normalized to a percentage scale between baseline and a T(sub O2) nadir reached during exercise to ischemic exhaustion. Over the course of exercise, T(sub O2) declined at a rate of 1.4 +/- 0.3% per minute with model CCS, yet did not decrease during control exercise. Post-exercise recovery of T(sub O2) was slower with model CCS (2.5 +/- 0.6 min) than in control (1.3 +/- 0.2 min). These results demonstrate that NIR spectroscopy can detect muscle deoxygenation caused by pathologically elevated intramuscular pressure in exercising skeletal muscle. Consequently, this technique shows promise as a

  3. Characterization of positron emission tomography hypoxia tracer uptake and tissue oxygenation via electrochemical modeling

    International Nuclear Information System (INIS)

    Purpose: Unique uptake and retention mechanisms of positron emission tomography (PET) hypoxia tracers make in vivo comparison between them challenging. Differences in imaged uptake of two common hypoxia radiotracers, [61Cu]Cu-ATSM and [18F]FMISO, were characterized via computational modeling to address these challenges. Materials and Methods: An electrochemical formalism describing bioreductive retention mechanisms of these tracers under steady-state conditions was adopted to relate time-averaged activity concentration to tissue partial oxygen tension (PO2), a common metric of hypoxia. Chemical equilibrium constants of product concentration to reactant concentration ratios were determined from free energy changes and reduction potentials of pertinent reactions reported in the literature. Resulting transformation functions between tracer uptake and PO2 were compared against measured values in preclinical models. Additionally, calculated PO2 distributions from imaged Cu-ATSM tracer activity concentrations of 12 head and neck squamous cell carcinoma (HNSCC) patients were validated against microelectrode PO2 measurements in 69 HNSCC patients. Results: Both Cu-ASTM- and FMISO-modeled PO2 transformation functions were in agreement with preclinical measured values within single-deviation confidence intervals. High correlation (r2=0.94, P2 distributions and measured distributions in the patient populations. On average, microelectrode hypoxia thresholds (2.5 and 5.0 mmHg) corresponded to higher Cu-ATSM uptake [2.5 and 2.0 standardized uptake value (SUV)] and lower FMISO uptake (2.0 and 1.4 SUV). Uncertainties in the models were dominated by variations in the estimated specific activity and intracellular acidity. Conclusions: Results indicated that the high dynamic range of Cu-ATSM uptake was representative of a narrow range of low oxygen tension whose values were dependent on microenvironment acidity, while FMISO uptake was representative of a wide range of PO2 values that

  4. Substrate stiffness and oxygen as regulators of stem cell differentiation during skeletal tissue regeneration: a mechanobiological model.

    Directory of Open Access Journals (Sweden)

    Darren Paul Burke

    Full Text Available Extrinsic mechanical signals have been implicated as key regulators of mesenchymal stem cell (MSC differentiation. It has been possible to test different hypotheses for mechano-regulated MSC differentiation by attempting to simulate regenerative events such as bone fracture repair, where repeatable spatial and temporal patterns of tissue differentiation occur. More recently, in vitro studies have identified other environmental cues such as substrate stiffness and oxygen tension as key regulators of MSC differentiation; however it remains unclear if and how such cues determine stem cell fate in vivo. As part of this study, a computational model was developed to test the hypothesis that substrate stiffness and oxygen tension regulate stem cell differentiation during fracture healing. Rather than assuming mechanical signals act directly on stem cells to determine their differentiation pathway, it is postulated that they act indirectly to regulate angiogenesis and hence partially determine the local oxygen environment within a regenerating tissue. Chondrogenesis of MSCs was hypothesized to occur in low oxygen regions, while in well vascularised regions of the regenerating tissue a soft local substrate was hypothesised to facilitate adipogenesis while a stiff substrate facilitated osteogenesis. Predictions from the model were compared to both experimental data and to predictions of a well established computational mechanobiological model where tissue differentiation is assumed to be regulated directly by the local mechanical environment. The model predicted all the major events of fracture repair, including cartilaginous bridging, endosteal and periosteal bony bridging and bone remodelling. It therefore provides support for the hypothesis that substrate stiffness and oxygen play a key role in regulating MSC fate during regenerative events such as fracture healing.

  5. Determinants of renal tissue oxygenation as measured with BOLD-MRI in chronic kidney disease and hypertension in humans.

    Directory of Open Access Journals (Sweden)

    Menno Pruijm

    Full Text Available Experimentally renal tissue hypoxia appears to play an important role in the pathogenesis of chronic kidney disease (CKD and arterial hypertension (AHT. In this study we measured renal tissue oxygenation and its determinants in humans using blood oxygenation level-dependent magnetic resonance imaging (BOLD-MRI under standardized hydration conditions. Four coronal slices were selected, and a multi gradient echo sequence was used to acquire T2* weighted images. The mean cortical and medullary R2* values ( = 1/T2* were calculated before and after administration of IV furosemide, a low R2* indicating a high tissue oxygenation. We studied 195 subjects (95 CKD, 58 treated AHT, and 42 healthy controls. Mean cortical R2 and medullary R2* were not significantly different between the groups at baseline. In stimulated conditions (furosemide injection, the decrease in R2* was significantly blunted in patients with CKD and AHT. In multivariate linear regression analyses, neither cortical nor medullary R2* were associated with eGFR or blood pressure, but cortical R2* correlated positively with male gender, blood glucose and uric acid levels. In conclusion, our data show that kidney oxygenation is tightly regulated in CKD and hypertensive patients at rest. However, the metabolic response to acute changes in sodium transport is altered in CKD and in AHT, despite preserved renal function in the latter group. This suggests the presence of early renal metabolic alterations in hypertension. The correlations between cortical R2* values, male gender, glycemia and uric acid levels suggest that these factors interfere with the regulation of renal tissue oxygenation.

  6. Comparative study between the effects of dexmedetomidine and propofol on cerebral oxygenation during sedation at pediatric cardiac catheterization

    OpenAIRE

    Murat Cetin; Handan Birbicer; Olgu Hallioglu; Gulhan Orekeci

    2016-01-01

    Introduction: Nowadays, assessment of brain oxygen saturation, which is simply appliable and noninvasive method, can provide the anesthesia plans to be optimized according to the needs of the brain, which is the main target organ. Brain may be exposed to hypoxia due to supply-demand imbalance of oxygen not only in general anesthesia procedures but also in sedation practices. The aim of the study is to compare the effects of dexmedetomidine and propofol which are widely used agents for pediatr...

  7. Cerebral Microcirculation during Experimental Normovolaemic Anemia

    Science.gov (United States)

    Bellapart, Judith; Cuthbertson, Kylie; Dunster, Kimble; Diab, Sara; Platts, David G.; Raffel, O. Christopher; Gabrielian, Levon; Barnett, Adrian; Paratz, Jenifer; Boots, Rob; Fraser, John F.

    2016-01-01

    Anemia is accepted among critically ill patients as an alternative to elective blood transfusion. This practice has been extrapolated to head injury patients with only one study comparing the effects of mild anemia on neurological outcome. There are no studies quantifying microcirculation during anemia. Experimental studies suggest that anemia leads to cerebral hypoxia and increased rates of infarction, but the lack of clinical equipoise, when testing the cerebral effects of transfusion among critically injured patients, supports the need of experimental studies. The aim of this study was to quantify cerebral microcirculation and the potential presence of axonal damage in an experimental model exposed to normovolaemic anemia, with the intention of describing possible limitations within management practices in critically ill patients. Under non-recovered anesthesia, six Merino sheep were instrumented using an intracardiac transeptal catheter to inject coded microspheres into the left atrium to ensure systemic and non-chaotic distribution. Cytometric analyses quantified cerebral microcirculation at specific regions of the brain. Amyloid precursor protein staining was used as an indicator of axonal damage. Animals were exposed to normovolaemic anemia by blood extractions from the indwelling arterial catheter with simultaneous fluid replacement through a venous central catheter. Simultaneous data recording from cerebral tissue oxygenation, intracranial pressure, and cardiac output was monitored. A regression model was used to examine the effects of anemia on microcirculation with a mixed model to control for repeated measures. Homogeneous and normal cerebral microcirculation with no evidence of axonal damage was present in all cerebral regions, with no temporal variability, concluding that acute normovolaemic anemia does not result in short-term effects on cerebral microcirculation in the ovine brain. PMID:26869986

  8. Tissue Kallikrein Alleviates Cerebral Ischemia-Reperfusion Injury by Activating the B2R-ERK1/2-CREB-Bcl-2 Signaling Pathway in Diabetic Rats

    Science.gov (United States)

    Yuan, Kunxiong; Hu, Bin; Sang, Hongfei; Xie, Yi; Xu, Lili; Cao, Qinqin; Chen, Xin; Zhao, Lingling; Liu, Xinfeng; Liu, Ling; Zhang, Renliang

    2016-01-01

    Diabetes mellitus (DM) substantially increases the risk of ischemic stroke and reduces the tolerance to ischemic insults. Tissue kallikrein (TK) has been demonstrated to protect neurons from ischemia/reperfusion (I/R) injury in orthoglycemic model by activating the bradykinin B2 receptor (B2R). Considering the differential effects of B2R or bradykinin B1 receptor (B1R) on cardioprotection and neuroprotection in I/R with or without diabetes, this study was designed to investigate the role of TK during cerebral I/R injury in streptozotocin-induced diabetic rats. Intravenous injection of TK inhibited apoptosis in neurons, alleviated edema and inflammatory reactions after focal cerebral I/R, significantly reduced the infarct volume, and improved functional recovery. These beneficial effects were accompanied by activation of the extracellular signal-regulated kinase 1/2 (ERK1/2), cAMP response element-binding (CREB), and Bcl-2 signal proteins. Inhibition of the B2R or ERK1/2 pathway abated the effects of TK, whereas an antagonist of B1R enhanced the effects. These findings reveal that the neuroprotective effect of TK against cerebral I/R injury in streptozotocin-induced diabetic rats mainly involves the enhancement of B2R and ERK1/2-CREB-Bcl-2 signaling pathway activity.

  9. Online oxygen kinetic isotope effects using membrane inlet mass spectrometry can differentiate between oxidases for mechanistic studies and calculation of their contributions to oxygen consumption in whole tissues.

    Science.gov (United States)

    Cheah, Mun Hon; Millar, A Harvey; Myers, Ruth C; Day, David A; Roth, Justine; Hillier, Warwick; Badger, Murray R

    2014-05-20

    The reduction chemistry of molecular oxygen underpins the energy metabolism of multicellular organisms, liberating free energy needed to catalyze a plethora of enzymatic reactions. Measuring the isotope signatures of (16)O and (18)O during O2 reduction can provide insights into both kinetic and equilibrium isotope effects. However, current methods to measure O2 isotope signatures are time-consuming and disruptive. This paper describes the application of membrane inlet mass spectrometry to determine the oxygen isotope discrimination of a range of O2-consuming reactions, providing a rapid and convenient method for determining these values. A survey of oxygenase and oxidase reactions provides new insights into previously uncharacterized amino acid oxidase enzymes. Liquid and gas phase measurements show the ease of assays using this approach for purified enzymes, biological extracts and intact tissues. PMID:24786640

  10. 2H,3H-decafluoropentane-based nanodroplets: new perspectives for oxygen delivery to hypoxic cutaneous tissues.

    Directory of Open Access Journals (Sweden)

    Mauro Prato

    Full Text Available Perfluoropentane (PFP-based oxygen-loaded nanobubbles (OLNBs were previously proposed as adjuvant therapeutic tools for pathologies of different etiology sharing hypoxia as a common feature, including cancer, infection, and autoimmunity. Here we introduce a new platform of oxygen nanocarriers, based on 2H,3H-decafluoropentane (DFP as core fluorocarbon. These new nanocarriers have been named oxygen-loaded nanodroplets (OLNDs since DFP is liquid at body temperature, unlike gaseous PFP. Dextran-shelled OLNDs, available either in liquid or gel formulations, display spherical morphology, ~600 nm diameters, anionic charge, good oxygen carrying capacity, and no toxic effects on human keratinocytes after cell internalization. In vitro OLNDs result more effective in releasing oxygen to hypoxic environments than former OLNBs, as demonstrated by analysis through oxymetry. In vivo, OLNDs effectively enhance oxy-hemoglobin levels, as emerged from investigation by photoacoustic imaging. Interestingly, ultrasound (US treatment further improves transdermal oxygen release from OLNDs. Taken together, these data suggest that US-activated, DFP-based OLNDs might be innovative, suitable and cost-effective devices to topically treat hypoxia-associated pathologies of the cutaneous tissues.

  11. 2H,3H-decafluoropentane-based nanodroplets: new perspectives for oxygen delivery to hypoxic cutaneous tissues.

    Science.gov (United States)

    Prato, Mauro; Magnetto, Chiara; Jose, Jithin; Khadjavi, Amina; Cavallo, Federica; Quaglino, Elena; Panariti, Alice; Rivolta, Ilaria; Benintende, Emilio; Varetto, Gianfranco; Argenziano, Monica; Troia, Adriano; Cavalli, Roberta; Guiot, Caterina

    2015-01-01

    Perfluoropentane (PFP)-based oxygen-loaded nanobubbles (OLNBs) were previously proposed as adjuvant therapeutic tools for pathologies of different etiology sharing hypoxia as a common feature, including cancer, infection, and autoimmunity. Here we introduce a new platform of oxygen nanocarriers, based on 2H,3H-decafluoropentane (DFP) as core fluorocarbon. These new nanocarriers have been named oxygen-loaded nanodroplets (OLNDs) since DFP is liquid at body temperature, unlike gaseous PFP. Dextran-shelled OLNDs, available either in liquid or gel formulations, display spherical morphology, ~600 nm diameters, anionic charge, good oxygen carrying capacity, and no toxic effects on human keratinocytes after cell internalization. In vitro OLNDs result more effective in releasing oxygen to hypoxic environments than former OLNBs, as demonstrated by analysis through oxymetry. In vivo, OLNDs effectively enhance oxy-hemoglobin levels, as emerged from investigation by photoacoustic imaging. Interestingly, ultrasound (US) treatment further improves transdermal oxygen release from OLNDs. Taken together, these data suggest that US-activated, DFP-based OLNDs might be innovative, suitable and cost-effective devices to topically treat hypoxia-associated pathologies of the cutaneous tissues. PMID:25781463

  12. 颅脑损伤患者高压氧治疗的观察和护理体会%Nursing Experience on Patients with Cerebral Injury Treated with Hyperbaric Oxygen

    Institute of Scientific and Technical Information of China (English)

    孙慧娟; 杨伟江; 姚含英; 孙昇

    2011-01-01

    Objective: To investigate the care for traumatic cerebral injury with hyperbaric oxygen therapy. Method: 60 patients with cerebral injury were randomly divided into two groups , one group was treated with hyperbaric oxygen therapy, and the other group on the basis of hyperbaric oxygen therapy were given the overall care, observed the effects before and after therapy. Result: Of hyperbaric oxygen treatment, care group, there was always more efficient than non-nursing group, the difference was statistically significant ( P <0.05 ). Conclusion: Hyperbaric oxygen therapy can improve the efficacy of cerebral injury, intensive care can promote recovery.%目的:探讨颅脑损伤高压氧治疗的护理效果.方法:将我院收治的颅脑损伤患者60例随机分成两组,一组给予高压氧进行治疗,另一组在高压氧治疗的基础上给予整体护理,观察理疗前后的疗效.结果:通过高压氧治疗后,护理组的总有效率高于非护理组,差异具有统计学意义(P<0.05).结论:高压氧治疗颅脑损伤能提高疗效,加强护理可促进康复.

  13. Characteristics of the oxygen regime in radiosensitive tissues in course of irradiation and with application of radiomodifying drugs

    International Nuclear Information System (INIS)

    Using the microelectrode polarography technique it has been found that the oxygen regime in the radiosensitive tissues (spleen) is drastically disturbed in the course of irradiation and during a short period thereupon. The effect manifests itself in phase changes of the pO2 resulting eventually in a profound hypoxia. It depends on irradiation dose and exposure time. 5-methoxytryptamine and cystamine alter the pattern of hypoxia development and stabilize the pO2 at a level as these radioprotective compounds usually do in radiosensitive tissues. (author)

  14. Circulatory and metabolic effects of glycerol infusion in patients with recent cerebral infarction.

    Science.gov (United States)

    Meyer, J S; Itoh, Y; Okamoto, S; Welch, K M; Mathew, N T; Ott, E O; Sakaki, S; Miyakawa, Y; Chabi, E; Ericsson, A D

    1975-04-01

    The effect of intravenous infusion of 10 per cent glycerol on regional cerebral blood flow (using hydrogen bolus and Xenon-133 (133Xe) clearance methods) and metabolism was investigated in 57 patients with recent cerebral infarction. Hemispheric blood flow (HBF) increased, together with increase in regional cerebral blood flow (rCBF) and cerebral blood volume (rCBV), in foci of brain ischemia. Hemispheric oxygen consumption (HMIO2) decreased together with hemispheric respiratory quotient. Systemic blood levels of glucose, lactate, pyruvate, and triglycerides also increased after glycerol while free fatty acids (FFA) and inorganic phosphate (Pi) decreased. Hemispheric glucose consumption was unaltered after glycerol so that hemispheric glucose to oxygen ratio tended to rise. Pyruvate and lactate production by brain was unchanged. Glycerol moved across the blood brain barrier into brain and cerebrospinal fluid (CSF). Release of FFA and Pi from infarcted brain was reversed by glycerol. Total phosphate balance was maintained actoss brain both before and after glycerol infusion. Triglycerides increased in CSF after glycerol, originating either from cerebral blood or as a result of lipogenesis in cerebral tissue. The EEG Recording and neurological status of the patients improved despite decreased brain oxygen consumption. Results of this study suggest that after intravenous infusion of 10 per cent glycerol in patients with recent cerebral infarction, glycerol rapidly enters the CSF and brain compartments and favorably affects the stroke process in two ways: first, by redistribution of cerebral blood flow with increase in rCBF and rCBV in ischemic brain secondary to reduction in focal cerebral edema; and second glycerol may become an alternative source of energy either by being directly metabolized by the brain, or indirectly, by enhancing lipogenesis, or by both processes. Involvement of glycerol in lipogenesis with esterification to accumulated FFA might lead to

  15. MULTILEVEL SOFT TISSUE WITH BONY CORRECTIVE SURGERY IN LOWER LIMB DEFORMITIES AS ONE SITTING PROCEDURE IN SPASTIC CEREBRAL PALSY: AN EXPERIENCE FROM FREE DISABLED SURGICAL CAMPS

    Directory of Open Access Journals (Sweden)

    Antony R

    2015-06-01

    Full Text Available The study was intended to assess the results of multilevel soft tissue with bony corrective surgery as one sitting procedure on static deformities and contractures in lower limbs with patients of spastic cerebral palsy at free disabled surgical camps at Chhattisgarh state. In our study 30 patients were included with sixty percent male and forty percent female , within 4 - 16 years age group. Almost all patients had diplegia and only few patients had quadriplegia with grade 3 power in both upper limbs. Improvement in functional ability and locomotion of all operated patients were asse ssed by gross motor functional classification scale and with physical examination. Almost all patients who were operated in our study showed significant improvement in functional abilities and locomotion after surgery. All patients were maintaining functional abilities at follow up duration of 2 years (24 months, with 70%. excellent cases gait of patient were normal or mild spastic but they were walking without support , with 20% good cases gait of patients were spastic but patients comfortably walk with short knee braces and with 10% fair cases gait of patients were scissors but patients walked comfortably with long knee braces . Our study shows that, promising results can be obtained in spastic cerebral palsy patients with static deformities and cont ractures of joints in lower limbs with multilevel soft tissue and bony corrective surgery. We believe that it’s a team effort of the surgeon , paramedical and rehabilitation staff in postoperative period for the achievement of better results.

  16. Analyzing Ph value, energy and phospholipid metabolism of various cerebral tumors and normal brain tissue with 31P magnetic resonance spectroscopy

    Institute of Scientific and Technical Information of China (English)

    Wei Tan; Guangyao Wu; Junmo Sun

    2006-01-01

    BACKGROUND: 31P magnetic resonance spectroscopy (31P MRS) can be used to non-injuredly and dynamicly detect various metabolites including phosphorus in organis and reflect changes of phospholipid metabolism and energy metabolism in tissue and pH value in cells.OBJECTIVE: To observe changes of pH value, phospholipid metabolism and energy metabolism of various cerebral tumors and normal brain tissue with 31P MRS.DESIGN: Semi-quantitative contrast observation.PARTICIPANTS: A total of 44 patients with cerebral tumor diagnosed with surgery operation were selected from the Department of Magnetic Resonance, Central South Hospital, Wuhan University from September 2004 to June 2006. All the subjects had complete 31P MRS data before steroid and operation. Among them,16 patients had glioma of grade Ⅱ-Ⅲ, 12 spongioblastoma and 16 meningioma. The mean age was (45±6)years. Another 36 subjects without focus on cerebral MRI were regarded as normal group, including 19 males and 18 females, and the mean age was (41±4) years. Included subjects were consent.METHODS: Eclipse1.5T MRS (Philips Company) was used to collect wave spectrum; jMRUI(1.3) was used to analyze experimental data and calculate pH value in voxel and ratios of phosphocreatine (PCr)/inorganic phosphate (Pi), PCr/phosphodiesterase (PDE) and phosphomonoesterase (PME)/β-adenosine triphosphate (β-ATP) of various metabolites. 31P MRS results were compared with t test between tumor patients and normal subjects.MAIN OUTCOME MEASURES: Changes of phospholipid metabolism (PME/PDE), energy metabolism (PCr/ATP) and pH value of various cerebral tumors and normal brain tissues.RESULTS: A total of 44 cases with cerebral tumor and 36 normal subjects were involved in the final analysis. pH value and semi-quantitative measurements of normal brain tissues and various cerebral tumors: ① pH value at top occipital region and temple occipital region of normal brain tissue was 7.04±0.02;PCt/β-ATP was 1.51 ±0.03; PCt/Pi was 2.85

  17. A Quantitative Near-Infrared Spectroscopy Study: A Decrease in Cerebral Hemoglobin Oxygenation in Alzheimer's Disease and Mild Cognitive Impairment

    Science.gov (United States)

    Arai, Heii; Takano, Maki; Miyakawa, Koichi; Ota, Tsuneyoshi; Takahashi, Tadashi; Asaka, Hirokazu; Kawaguchi, Tsuneaki

    2006-01-01

    A newly developed quantitative near-infrared spectroscopy (NIRS) system was used to measure changes in cortical hemoglobin oxygenation during the Verbal Fluency Task in 32 healthy controls, 15 subjects with mild cognitive impairment (MCI), and 15 patients with Alzheimer's disease (AD). The amplitude of changes in the waveform, which was…

  18. Changes in serum cellular adhesion molecule and matrix metalloproteinase-9 levels in patients with cerebral infarction following hyperbaric oxygen therapy A case and intergroup control study

    Institute of Scientific and Technical Information of China (English)

    Renliang Zhao; Chunxia Wang; Yongjun Wang

    2008-01-01

    BACKGROUND: Animal studies have confirmed that hyperbaric oxygen (HBO) therapy can reduce matrix metalloproteinase activity and blood brain barrier permeability, thereby exhibiting neuroprotective effects. However, at present, consensus does not exist in terms of its clinical efficacy. OBJECTIVE: To validate the significance of changes in serum cellular adhesion molecule and MMP-9 levels in patients with cerebral infarction following HBO therapy. DESIGN, TIME AND SETTING: This randomized, controlled, neurobiochemical study was performed at the Department of Neurology, Affiliated Hospital of Qingdao University Medical College between December 2002 and March 2006. PARTICIPANTS: A total of 112 patients with acute cerebral infarction of internal carotid artery, comprising 64 males and 48 females, averaging (67 ± 11) years, were recruited and randomized to a HBO group (n = 50) and a routine treatment group (n = 62). An additional 30 gender- and age-matched normal subjects, consisting of 17 males and 13 females, averaging (63 ± 9) years, were enrolled as control subjects. METHODS: The routine treatment group received routine drug treatment and rehabilitation exercise. HBO treatment was additionally performed in the HBO group, once a day, for a total of 10 days. MAIN OUTCOME MEASURES: Serum levels of soluble intercellular adhesion molecule, soluble vascular cell adhesion molecule, soluble E-selectin, and matrix metalloproteinase-9 were detected by enzyme linked immunosorbent assay. RESULTS: Upon admission, serum levels of soluble intercellular adhesion molecule, soluble vascular cell adhesion molecule, soluble E-selectin, and matrix metalloproteinase-9 were significantly increased in patients with cerebral infarction, compared with control subjects (P < 0.01). Following HBO and routine treatments, serum levels of the above-mentioned indices were significantly reduced in the HBO and routine treatment groups (P < 0.01). Moreover, greater efficacy was observed in the HBO

  19. Total Flavone of Hawthorn Leaf inhibits neuronal apoptosis in brain tissue of rat models of chronic cerebral ischemia

    Institute of Scientific and Technical Information of China (English)

    Tan Rong-fang; Xia Ai-hua; Wu Xiao-guang; Cao Na-na; Li Meng-meng; Zhang Tian-ge; Wang Yi-ru; Yue Zhi-ling

    2014-01-01

    BACKGROUND: Cerebrovascular disease often causes dysfunction of the brain nerve, and nerve cel apoptosis is the important factor of cerebral nerve dysfunction. The excessive expression of c-fos can block the transduction of intracelular signal so that producing some apoptosis-promoting factors, which involve in nerve cel apoptosis process after ischemia injury of brain. Bcl-2 is an inhibited factor. It might to be the key to treat ischemic cerebrovascular disease by inhibiting or reducing the apoptosis of nerve cels after ischemia injury. OBJECTIVE: To investigate the therapeutic effect and mechanism of the Total Flavone of Hawthorn Leaf on chronic cerebral ischemia rats. METHODS: A total of 72 healthy male Sprague-Dawley rats were randomly divided into sham surgery group, model group, Total Flavone of Hawthorn Leaf group and ginkgo leaf group. Permanent bilateral carotid artery ligation was used to prepare chronic cerebral ischemia model in the model group, Total Flavone of Hawthorn Leaf group and ginkgo leaf group. Total Flavone of Hawthorn Leaf group and ginkgo leaf group respectively received 140 mg/kg Total Flavone of Hawthorn Leaf and 12.3 mg/kg ginkgo leaf intragastricaly for 36 days from 36 days after model induction. Model group and sham surgery group received 3.5 mL/kg physiological saline intragastricaly. RESULTS AND CONCLUSION: Compared with the model group, the expression of c-fos protein significantly deceased in the Total Flavone of Hawthorn Leaf group (P 0.05). These data indicated that the protective effect of Total Flavone of Hawthorn Leaf on chronic cerebral ischemia was associated with its inhibition of neuronal apoptosis. Its mechanism of anti-apoptosis might be associated with up-regulating expression of Bcl-2, down-regulating expression of c-fos and decreasing Ca2+ content in brain.

  20. Increased Cerebral Oxygen Metabolism and Ischemic Stress in Subjects with Metabolic Syndrome-Associated Risk Factors: Preliminary Observations

    OpenAIRE

    Uchino, Ken; Lin, Ridwan; Zaidi, Syed F.; Kuwabara, Hiroto; Sashin, Donald; Bircher, Nicholas; Chang, Yue-Fang; Hammer, Maxim D.; Reddy, Vivek; Jovin, Tudor G.; Vora, Nirav; Jumaa, Mouhammad; Massaro, Lori; Billigen, Julia; Boada, Fernando

    2010-01-01

    Hypertension, diabetes, obesity, and dyslipidemia are risk factors that characterize metabolic syndrome (MetS), which increases the risk for stroke by 40%. In a preliminary study, our aim was to evaluate cerebrovascular reactivity and oxygen metabolism in subjects free of vascular disease but with one or more of these risk factors. Volunteers (n=15) 59±15 (mean±SD)years of age clear of cerebrovascular disease by magnetic resonance angiography but with one or more risk factors were studied by ...

  1. Gene interference regulates aquaporin-4 expression in swollen tissue of rats with cerebral ischemic edema Correlation with variation in apparent diffusion coefficient

    Institute of Scientific and Technical Information of China (English)

    Hui Hu; Hong Lu; Zhanping He; Xiangjun Han; Jing Chen; Rong Tu

    2012-01-01

    To investigate the effects of mRNA interference on aquaporin-4 expression in swollen tissue of rats with ischemic cerebral edema, and diagnose the significance of diffusion-weighted MRI, we injected 5 μL shRNA- aquaporin-4 (control group) or siRNA- aquaporin-4 solution (1:800) (RNA interference group) into the rat right basal ganglia immediately before occlusion of the middle cerebral artery. At 0.25 hours after occlusion of the middle cerebral artery, diffusion-weighted MRI displayed a high signal; within 2 hours, the relative apparent diffusion coefficient decreased markedly, aquaporin-4 expression increased rapidly, and intracellular edema was obviously aggravated; at 4 and 6 hours, the relative apparent diffusion coefficient slowly returned to control levels, aquaporin-4 expression slightly increased, and angioedema was observed. In the RNA interference group, during 0.25- 6 hours after injection of siRNA- aquaporin-4 solution, the relative apparent diffusion coefficient slightly fluctuated and aquaporin-4 expression was upregulated; during 0.5-4 hours, the relative apparent diffusion coefficient was significantly higher, while aquaporin-4 expression was significantly lower when compared with the control group, and intracellular edema was markedly reduced; at 0.25 and 6 hours, the relative apparent diffusion coefficient and aquaporin-4 expression were similar when compared with the control group; obvious angioedema remained at 6 hours. Pearson's correlation test results showed that aquaporin-4 expression was negatively correlated with the apparent diffusion coefficient (r = -0.806, P < 0.01). These findings suggest that upregulated aquaporin-4 expression is likely to be the main molecular mechanism of intracellular edema and may be the molecular basis for decreased relative apparent diffusion coefficient. Aquaporin-4 gene interference can effectively inhibit the upregulation of aquaporin-4 expression during the stage of intracellular edema with time

  2. An upgraded camera-based imaging system for mapping venous blood oxygenation in human skin tissue

    Science.gov (United States)

    Li, Jun; Zhang, Xiao; Qiu, Lina; Leotta, Daniel F.

    2016-07-01

    A camera-based imaging system was previously developed for mapping venous blood oxygenation in human skin. However, several limitations were realized in later applications, which could lead to either significant bias in the estimated oxygen saturation value or poor spatial resolution in the map of the oxygen saturation. To overcome these issues, an upgraded system was developed using improved modeling and image processing algorithms. In the modeling, Monte Carlo (MC) simulation was used to verify the effectiveness of the ratio-to-ratio method for semi-infinite and two-layer skin models, and then the relationship between the venous oxygen saturation and the ratio-to-ratio was determined. The improved image processing algorithms included surface curvature correction and motion compensation. The curvature correction is necessary when the imaged skin surface is uneven. The motion compensation is critical for the imaging system because surface motion is inevitable when the venous volume alteration is induced by cuff inflation. In addition to the modeling and image processing algorithms in the upgraded system, a ring light guide was used to achieve perpendicular and uniform incidence of light. Cross-polarization detection was also adopted to suppress surface specular reflection. The upgraded system was applied to mapping of venous oxygen saturation in the palm, opisthenar and forearm of human subjects. The spatial resolution of the oxygenation map achieved is much better than that of the original system. In addition, the mean values of the venous oxygen saturation for the three locations were verified with a commercial near-infrared spectroscopy system and were consistent with previously published data.

  3. Study on changes of partial pressure of brain tissue oxygen and brain temperature in acute phase of severe head injury during mild hypothermia therapy

    Institute of Scientific and Technical Information of China (English)

    朱岩湘; 姚杰; 卢尚坤; 章更生; 周关仁

    2003-01-01

    Objective: To study the changes of partial pressure of brain tissue oxygen (PbtO2) and brain temperature in acute phase of severe head injury during mild hypothermia therapy and the clinical significance.Methods: One hundred and sixteen patients with severe head injury were selected and divided into a mild hypothermia group (n=58), and a control group (n=58) according to odd and even numbers of hospitalization. While mild hypothermia therapy was performed PbtO2 and brain temperature were monitored for 1-7 days (mean=86 hours), simultaneously, the intracranial pressure, rectum temperature, cerebral perfusion pressure, PaO2 and PaCO2 were also monitored. The patients were followed up for 6 months and the prognosis was evaluated with GOS (Glasgow outcome scale).Results: The mean value of PbtO2 within 24 hour monitoring in the 116 patients was 13.7 mm Hg±4.94 mm Hg, lower than the normal value (16 mm Hg±40 mm Hg) The time of PbtO2 recovering to the normal value in the mild hypothermia group was shortened by 10±4.15 hours compared with the control group (P<0.05). The survival rate of the mild hypothermia group was 60.43%, higher than that of the control group (46.55%). After the recovery of the brain temperature, PbtO2 increased with the rise of the brain temperature. Conclusions: Mild hypothermia can improve the survival rate of severe head injury. The technique of monitoring PbtO2 and the brain temperature is safe and reliable, and has important clinical significance in judging disease condition and instructing clinical therapy.

  4. Craniofacial tissue oxygen saturation is associated with blood pH using an examiner's finger-mounted tissue oximetry in mice

    Science.gov (United States)

    Uchida, Toshiyuki; Kanayama, Naohiro; Kawai, Kenta; Niwayama, Masatsugu

    2016-04-01

    Although fetal scalp blood sampling is an examination to assess fetal acidosis during the intrapartum period, it has not been widely used by obstetricians because of its invasiveness. We have developed a small, portable oximetry with a sensor attached to the examiner's finger. Our previous report using this oximetry concluded that fetal head tissue oxygen saturation (StO2) correlated with umbilical cord artery blood pH. We investigated whether the association between StO2 and blood pH in mice could be validated using this oximetry. Eleven the Institute for Cancer Research (ICR) mice were measured using a near-infrared spectroscopy probe at the craniofacial site in a closed polyethylene bag while changing the oxygen concentration. A total of nine blood samples were collected and analyzed for pH. The StO2 and tissue blood pH showed a strong positive correlation (r=0.90 and P=0.0009). The StO2 and total hemoglobin index also showed a positive correlation (r=0.84 and P=0.0049). Thus, the results of the present study support those of our previous report on clinical cases and allow examiners to easily check the status of fetal acidosis. Fetal management using this oximetry might gain popularity with obstetricians in the near future.

  5. Cerebral Hypoxia

    Science.gov (United States)

    ... Enhancing Diversity Find People About NINDS NINDS Cerebral Hypoxia Information Page Synonym(s): Hypoxia, Anoxia Table of Contents ( ... Trials Organizations Publicaciones en Español What is Cerebral Hypoxia? Cerebral hypoxia refers to a condition in which ...

  6. Radiosensitisation in normal tissues with oxygen, carbogen or nicotinamide: therapeutic gain comparisons for fractionated x-ray schedules

    International Nuclear Information System (INIS)

    Methods: Radiosensitisation with oxygen, carbogen or nicotinamide alone and oxygen or carbogen combined with nicotinamide was compared in early and late responding normal tissues in rodents. X-ray treatments were delivered as single doses or fractionated schedules of 2 fractions in 1 day, 2, 12 and 36 fractions in an overall time of 12 days and 10 fractions in 5 or 12 days. Acute skin reactions, survival of intestinal crypts, breathing rate, reduction in the packed red-cell volume and clearance of 51Cr-EDTA were used as assays of epidermal, gut, lung and renal damage. Results: Relative to air-breathing mice, carbogen or oxygen produced a small, and not always significant, increase in sensitivity (enhancement ratios ≤ 1.15) in gut, lung and kidneys; however, in skin a dose enhancement of 1.2-1.3 was observed. The effect of nicotinamide in air, carbogen or oxygen was studied only in lung and gut. The drug produced variable but generally significant increases in radiosensitisation (≤ 1.26) in all three gases. Relative to treatments in air, enhancement ratios for nicotinamide alone were usually slightly higher than those observed when either carbogen or oxygen were administered without the drug. With all three modifiers (i.e. oxygen, carbogen, nicotinamide alone or for the drug-gas combinations) there was no significant change in the enhancement ratios observed as the number of radiation dose fractions was varied. Conclusions: Comparisons with fractionated X-ray studies done previously in rodent tumours indicate that a therapeutic benefit, relative to lung, gut and renal damage, would be observed with oxygen or carbogen alone but not with nicotinamide alone. The greatest gain would be achieved with the combination of carbogen and nicotinamide, with which a benefit was observed even relative to epidermal damage. These results indicate that some decrease in normal tissue tolerance could be observed when using these modifiers in clinical radiotherapy and, although

  7. MR vascular fingerprinting: A new approach to compute cerebral blood volume, mean vessel radius, and oxygenation maps in the human brain.

    Science.gov (United States)

    Christen, T; Pannetier, N A; Ni, W W; Qiu, D; Moseley, M E; Schuff, N; Zaharchuk, G

    2014-04-01

    In the present study, we describe a fingerprinting approach to analyze the time evolution of the MR signal and retrieve quantitative information about the microvascular network. We used a Gradient Echo Sampling of the Free Induction Decay and Spin Echo (GESFIDE) sequence and defined a fingerprint as the ratio of signals acquired pre- and post-injection of an iron-based contrast agent. We then simulated the same experiment with an advanced numerical tool that takes a virtual voxel containing blood vessels as input, then computes microscopic magnetic fields and water diffusion effects, and eventually derives the expected MR signal evolution. The parameter inputs of the simulations (cerebral blood volume [CBV], mean vessel radius [R], and blood oxygen saturation [SO2]) were varied to obtain a dictionary of all possible signal evolutions. The best fit between the observed fingerprint and the dictionary was then determined by using least square minimization. This approach was evaluated in 5 normal subjects and the results were compared to those obtained by using more conventional MR methods, steady-state contrast imaging for CBV and R and a global measure of oxygenation obtained from the superior sagittal sinus for SO2. The fingerprinting method enabled the creation of high-resolution parametric maps of the microvascular network showing expected contrast and fine details. Numerical values in gray matter (CBV=3.1±0.7%, R=12.6±2.4μm, SO2=59.5±4.7%) are consistent with literature reports and correlated with conventional MR approaches. SO2 values in white matter (53.0±4.0%) were slightly lower than expected. Numerous improvements can easily be made and the method should be useful to study brain pathologies. PMID:24321559

  8. Electro-acupuncture for STAT3 expression and nuclear translocation in hippocampal tissues of rats following cerebral ischemia/reperfusion

    Institute of Scientific and Technical Information of China (English)

    Lihong Kong; Xiaoling Zeng; Guojie Sun; Shenghong Liu

    2006-01-01

    BACKGROUND: It has been found in recent years that STATS widely distributes in nervous system, including hippocampal CA1-3 region, dentate gyrus and cerebral neocortex, etc. Ischemic brain injury can cause the release of some cytokines and growth factors, while electro-acupuncture may have multi-level, multi-channel and multi-target protective and interventional effects on ischemic brain injury.OBJ ECTIVE: To observe the effects of electro-acupuncture on STAT3 expression and nuclear translocation in hippocampal CA1 region of rat models of brain ischemia/reperfusion.DESIGN: Randomized and controlled observation.SETTING: Staff Room of Acupuncture and Moxibustion, Department of Acupuncture and Bone Injury,Hubei College of Traditional Chinese Medicine; Tongji Medical College, Huazhong University of Science and Technology.MATERTALS: Seventy-two healthy SD rats, of clean degree and either gender, weighing (200±20) g, were provided by the Experimental Animal Center of Hubei College of Traditional Chinese Medicine. STAT3monoclonal antibody was purchased from Santa Cruz Company, USA, and G-6805 electro-acupuncture instrument was purchased from Shanghai Medical Electronic Instruments Factory.METHODS: This experiment was carried out in the comprehensive laboratory of Department of Acupuncture and Bone Injury, Hubei College of Traditional Chinese Medicine between September 2005 and February 2006.Seventy-two rats were randomly divided into 4 groups: ① control group(n =6): Untouched. ② Sham-operation group (n =18): Artery was isolated, but without inserting thread bolt.③ Model group (n =24): Rat models of local brain ischemia/reperfusion were established with modified suture occlusion. ④Electro-acupuncture group (n =24): Dazhui and bilateral Neiguan points were selected for electro-acupuncture treatment. No. 28acupuncture needle of 3.33 cm was used in the treatment A G-6085 electro-acupuncture instrument with continuous wave, frequency of 120 times/min, intensity of 1 m

  9. Cerebral perfusion SPECT imaging for assessment of the effect of hyperbaric oxygen therapy on patients with postbrain injury neural status

    Institute of Scientific and Technical Information of China (English)

    施小燕; 汤宗泉; 熊冰; 包建秀; 孙达; 张云秋; 姚瑜

    2003-01-01

    Objective: To evaluate the effects of hyperbaric oxygen (HBO) therapy on patients with postbrain injury neural status.Methods: Two to 4 courses of HBO therapy and/or medications were used to treat 320 patients who were randomly divided into two groups. Assessment was made with 99mTc-ethyl cysteinate dimer (99mTc-ECD) single photon emission computed tomography (SPECT) before and after treatment. Results: There was a significant difference between the HBO therapy group and the non-HBO therapy group. HBO therapy was superior to medication treatment alone in the recovery of clinical symptoms, control of epilepsy, and resolution of hydrocephalus (P<0.01). Conclusions: HBO therapy has specific curative effects on patients with postbrain injury neural status, and 99mTc-ECD SPECT could play an important role in diagnosing postbrain injury neural status and monitoring the therapeutic effects of HBO.

  10. Cerebral effects of commonly used vasopressor-inotropes: a study in newborn piglets.

    Directory of Open Access Journals (Sweden)

    Gitte H Hahn

    Full Text Available BACKGROUND: Despite widespread use in sick infants, it is still debated whether vasopressor-inotropes have direct cerebral effects that might affect neurological outcome. We aimed to test direct cerebrovascular effects of three commonly used vasopressor-inotropes (adrenaline, dopamine and noradrenaline by comparing the responses to those of nonpharmacologically induced increases in blood pressure. We also searched for reasons for a mismatch between the response in perfusion and oxygenation. METHODS: Twenty-four piglets had long and short infusions of the three vasopressor-inotropes titrated to raise mean arterial blood pressure (MAP 10 mmHg in random order. Nonpharmacological increases in MAP were induced by inflation of a balloon in the descending aorta. We measured cerebral oxygenation (near-infrared spectroscopy, perfusion (laser-Doppler, oxygen consumption (co-oximetry of arterial and superior sagittal sinus blood, and microvascular heterogeneity (side stream dark field video microscopy. RESULTS: Vasopressor-inotropes increased cerebral oxygenation significantly less (p≤0.01 compared to non-pharmacological MAP increases, whereas perfusion was similar. Furthermore, cerebral total hemoglobin concentration increased significantly less during vasopressor-inotrope infusions (p = 0.001. These physiologic responses were identical between the three vasopressor-inotropes (p>0.05. Furthermore, they induced a mild, although insignificant increase in cerebral metabolism and microvascular heterogeneity (p>0.05. Removal of the scalp tissue did not influence the mismatch (p>0.05. CONCLUSION: We demonstrated a moderate vasopressor-inotrope induced mismatch between cerebral perfusion and oxygenation. Scalp removal did not affect this mismatch, why vasopressor-inotropes appear to have direct cerebral actions. The statistically nonsignificant increases in cerebral metabolism and/or microvascular heterogeneity may explain the mismatch. Alternatively, it

  11. Enhanced cerebrovascular expression of matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 via the MEK/ERK pathway during cerebral ischemia in the rat

    DEFF Research Database (Denmark)

    Maddahi, Aida; Chen, Qingwen; Edvinsson, Lars

    2009-01-01

    metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1). RESULTS: Here, we found an infarct volume of 24.8 +/- 2% and a reduced neurological function after two hours of middle cerebral artery occlusion (MCAO), followed by 48 hours of recirculation in rat. Immunocytochemistry and confocal...... microscopy revealed enhanced expression of MMP-9, TIMP-1, and phosphorylated ERK1/2 in the smooth muscle cells of the ischemic MCA and associated intracerebral microvessels. The specific MEK1/2 inhibitor U0126, given intraperitoneal zero or 6 hours after the ischemic event, reduced the infarct volume...... significantly (11.8 +/- 2% and 14.6 +/- 3%, respectively; P <0.05), improved neurological function, normalized expression of phosphorylated ERK1/2, and reduced expression of MMP-9 and TIMP-1 in the vessel walls. Administration of U0126 12 hours after MCAO did not alter the expression of MMP-9...

  12. Clinical Neuroimaging of cerebral ischemia

    International Nuclear Information System (INIS)

    Notice points in clinical imaging of cerebral ischemia are reviewed. When cerebral blood flow is determined in acute stage of cerebral embolism (cerebral blood flow SPECT), it is important to find area of ischemic core and ischemic penumbra. When large cortex area is assigned to ischemic penumbra, thrombolytic therapy is positively adapted, but cautious correspondence is necessary when ischemic core is recognized. DWI is superior in the detection of area equivalent to ischemic core of early stage, but, in imaging of area equivalent to ischemic penumbra, perfusion image or distribution image of cerebral blood volume (CBV) by MRI need to be combined. Luxury perfusion detected by cerebral blood flow SPECT in the cases of acute cerebral embolism suggests vascular recanalization, but a comparison with CT/MRI and continuous assessment of cerebral circulation dynamics were necessary in order to predict brain tissue disease (metabolic abnormality). In hemodynamic cerebral ischemia, it is important to find stage 2 equivalent to misery perfusion by quantification of cerebral blood flow SPECT. Degree of diaschisis can indicate seriousness of brain dysfunction for lacuna infarct. Because cerebral circulation reserve ability (perfusion pressure) is normal in all areas of the low cerebral blood flow by diaschisis mechanism, their areas are easily distinguished from those of hemodynamic cerebral ischemia. (K.H.)

  13. Spontaneous calcium waves in Bergman glia increase with age and hypoxia and may reduce tissue oxygen

    DEFF Research Database (Denmark)

    Mathiesen, Claus; Brazhe, Alexey; Thomsen, Kirsten Joan;

    2013-01-01

    Glial calcium (Ca(2+)) waves constitute a means to spread signals between glial cells and to neighboring neurons and blood vessels. These waves occur spontaneously in Bergmann glia (BG) of the mouse cerebellar cortex in vivo. Here, we tested three hypotheses: (1) aging and reduced blood oxygen sa...

  14. Effects of Reduced Oxygen and Glucose Levels on Ocular Cells in vitro: Implications for Tissue Models

    OpenAIRE

    Sander, Edward A.; Nauman, Eric A.

    2009-01-01

    An important goal of tissue engineering is the development of better in vitro tissue models for the study and treatment of diseases, especially those that are difficult to model in animals, such as glaucoma. In order to properly interpret experimental results designed to mimic in vivo conditions, it is necessary to characterize the metabolic state of the in vitro culture. The goal of this study was to determine how porcine lamina cribrosa cells (PLC), porcine scleral fibroblasts (PSC) and rat...

  15. Recombinant Tissue Plasminogen Activator Induces Neurological Side Effects Independent on Thrombolysis in Mechanical Animal Models of Focal Cerebral Infarction: A Systematic Review and Meta-Analysis.

    Directory of Open Access Journals (Sweden)

    Mei-Xue Dong

    Full Text Available Recombinant tissue plasminogen activator (rtPA is the only effective drug approved by US FDA to treat ischemic stroke, and it contains pleiotropic effects besides thrombolysis. We performed a meta-analysis to clarify effect of tissue plasminogen activator (tPA on cerebral infarction besides its thrombolysis property in mechanical animal stroke.Relevant studies were identified by two reviewers after searching online databases, including Pubmed, Embase, and ScienceDirect, from 1979 to 2016. We identified 6, 65, 17, 12, 16, 12 and 13 comparisons reporting effect of endogenous tPA on infarction volume and effects of rtPA on infarction volume, blood-brain barrier, brain edema, intracerebral hemorrhage, neurological function and mortality rate in all 47 included studies. Standardized mean differences for continuous measures and risk ratio for dichotomous measures were calculated to assess the effects of endogenous tPA and rtPA on cerebral infarction in animals. The quality of included studies was assessed using the Stroke Therapy Academic Industry Roundtable score. Subgroup analysis, meta-regression and sensitivity analysis were performed to explore sources of heterogeneity. Funnel plot, Trim and Fill method and Egger's test were obtained to detect publication bias.We found that both endogenous tPA and rtPA had not enlarged infarction volume, or deteriorated neurological function. However, rtPA would disrupt blood-brain barrier, aggravate brain edema, induce intracerebral hemorrhage and increase mortality rate.This meta-analysis reveals rtPA can lead to neurological side effects besides thrombolysis in mechanical animal stroke, which may account for clinical exacerbation for stroke patients that do not achieve vascular recanalization with rtPA.

  16. Effect of mild hypothermia on partial pressure of oxygen in brain tissue and brain temperature in patients with severe head injury

    Institute of Scientific and Technical Information of China (English)

    张赛; 只达石; 林欣; 尚彦国; 牛玉德

    2002-01-01

    Objective: To study the changes of partial pressure of oxygen in brain tissue (PbtO2) and brain temperature (BT) in patients in acute phase of severe head injury, and to study the effect of mild hypothermia on PbtO2 and BT.   Methods: The PbtO2 and the BT of 18 patients with severe head injury were monitored, and the patients were treated with mild hypothermia within 20 hours after injury. The rectal temperature (RT) of the patients was kept on 31.5-34.9℃ for 1-7 days (57.7 hours±28.4 hours averagely), simultaneously, the indexes of PbtO2 and BT were monitored for 1-5 days (with an average of 54.8 hours±27.0 hours). According to Glasgow Outcome Scale (GOS), the prognosis of the patients was evaluated at 6 months after injury.   Results: Within 24 hours after severe head injury, the PbtO2 was significantly lower (9.6 mm Hg±6.8 mm Hg, 1 mm Hg=0.133 kPa) than the normal value (16-40 mm Hg). After treatment of mild hypothermia, the mean PbtO2 increased to 28.7 mm Hg±8.8 mm Hg during the first 24 hours, and the PbtO2 was still maintained within the range of normal value at 3 days after injury. The BT was higher than the RT in the patients in acute phase of severe head injury, and the difference between the BT and the RT significantly increased after treatment of mild hypothermia. Hyperventilation (the partial pressure of carbon dioxide in artery (PaCO2)≈25 mm Hg) decreased the high intracranial pressure (ICP) and significantly decreased the PbtO2.   Conclusions: This study demonstrates that PptO2 and BT monitoring is a safe, reliable and sensitive diagnostic method to follow cerebral oxygenation. It might become an important tool in our treatment regime for patients in the acute phase of severe head injury requiring hypothermia and hyperventilation.

  17. A Microperfusion and In-Bore Oxygenator System Designed for Magnetic Resonance Microscopy Studies on Living Tissue Explants

    Science.gov (United States)

    Flint, Jeremy J.; Menon, Kannan; Hansen, Brian; Forder, John; Blackband, Stephen J.

    2015-12-01

    Spectrometers now offer the field strengths necessary to visualize mammalian cells but were not designed to accommodate imaging of live tissues. As such, spectrometers pose significant challenges—the most evident of which are spatial limitations—to conducting experiments in living tissue. This limitation becomes problematic upon trying to employ commercial perfusion equipment which is bulky and—being designed almost exclusively for light microscopy or electrophysiology studies—seldom includes MR-compatibility as a design criterion. To overcome problems exclusive to ultra-high magnetic field environments with limited spatial access, we have designed microperfusion and in-bore oxygenation systems capable of interfacing with Bruker’s series of micro surface-coils. These devices are designed for supporting cellular resolution imaging in MR studies of excised, living tissue. The combined system allows for precise control of both dissolved gas and pH levels in the perfusate thus demonstrating applicability for a wide range of tissue types. Its compactness, linear architecture, and MR-compatible material content are key design features intended to provide a versatile hardware interface compatible with any NMR spectrometer. Such attributes will ensure the microperfusion rig’s continued utility as it may be used with a multitude of contemporary NMR systems in addition to those which are currently in development.

  18. Muscle tissue oxygenation, pressure, electrical, and mechanical responses during dynamic and static voluntary contractions

    DEFF Research Database (Denmark)

    Vedsted, Pernille; Blangsted, Anne Katrine; Søgaard, Karen;

    2006-01-01

    Dynamic muscle contractions have been shown to cause greater energy turnover and fatigue than static contractions performed at a corresponding force level. Therefore, we hypothesized that: (1) electro- (EMG) and mechanomyography (MMG), intramuscular pressure (IMP), and reduction in muscle oxygen...... tension (rTO(2)) would be larger during dynamic (DYN) than intermittent static (IST) low force contractions; and that (2) oxygen tension would remain lower in the resting periods subsequent to DYN as compared to those following IST. Eight subjects performed elbow flexions with identical time......-tension products: (1) DYN as a 20 degrees elbow movement of 2 s concentric and 2 s eccentric followed by a 4 s rest; and (2) IST with a 4 s contraction followed by a 4 s rest. Each session was performed for 1 min at 10 and 20% of the maximal voluntary contraction (MVC). The force, bipolar surface EMG, MMG, IMP, r...

  19. Evidence of a heterogeneous tissue oxygenation: renal ischemia/reperfusion injury in a large animal model

    Science.gov (United States)

    Crane, Nicole J.; Huffman, Scott W.; Alemozaffar, Mehrdad; Gage, Frederick A.; Levin, Ira W.; Elster, Eric A.

    2013-03-01

    Renal ischemia that occurs intraoperatively during procedures requiring clamping of the renal artery (such as renal procurement for transplantation and partial nephrectomy for renal cancer) is known to have a significant impact on the viability of that kidney. To better understand the dynamics of intraoperative renal ischemia and recovery of renal oxygenation during reperfusion, a visible reflectance imaging system (VRIS) was developed to measure renal oxygenation during renal artery clamping in both cooled and warm porcine kidneys. For all kidneys, normothermic and hypothermic, visible reflectance imaging demonstrated a spatially distinct decrease in the relative oxy-hemoglobin concentration (%HbO2) of the superior pole of the kidney compared to the middle or inferior pole. Mean relative oxy-hemoglobin concentrations decrease more significantly during ischemia for normothermic kidneys compared to hypothermic kidneys. VRIS may be broadly applicable to provide an indicator of organ ischemia during open and laparoscopic procedures.

  20. Intra-arterial tert-Butyl-Hydroperoxide Infusion Induces an Exacerbated Sensory Response in the Rat Hind Limb and is Associated with an Impaired Tissue Oxygen Uptake

    OpenAIRE

    Tan, Edward C. T. H.; van Goor, Harry; Bahrami, Soheyl; Kozlov, Andrey V; Leixnering, Martin; Redl, Heinz; Goris, R. Jan A.

    2010-01-01

    The objective of this study was to investigate oxidative stress and oxygen extraction mechanisms in an animal model of continuous intra-arterial infusion of a free radical donor and in an in vitro model using isolated mitochondria. tert-Butyl-hydroperoxide (tert-BuOOH, 25 mM) was infused for 24 h in the left hind limb of rats to induce soft tissue damage (n = 8). After 7 days, we assessed local sensory response, tissue oxygen consumption, oxygen radicals, and antioxidant levels. In vitro mito...

  1. Concentration of labelled polyphosphates in soft tissue lesions. Application to the study of cerebral and myocardial infarction

    International Nuclear Information System (INIS)

    The biological behavior and tissue localization of phosphorus compounds used in Nuclear Medicine are reviewed. The mechanism of skeletal localization is emphasized. Labeled pyrophosphate compounds have proved extremely useful for skeletal imaging, however the mechanism of increased accumulation of these agents has been observed also in soft tissues. They localize in the acutely infarcted myocardium and in brain lesions. Clinical results obtained with sup(99m)Tc stannous pyrophosphate in brain and myocardium imaging are reported

  2. Enantioselective S-oxygenation of para-methoxyphenyl-1,3-dithiolane by various tissue preparations: effect of estradiol.

    Science.gov (United States)

    Cashman, J R; Olsen, L D; Lambert, C E; Presas, M J

    1990-02-01

    Liver, kidney, and lung microsomes prepared from nonpretreated female Sprague-Dawley rats catalyze the NADPH- and oxygen-dependent S-oxygenation of para-methoxyphenyl-1,3-dithiolane. Studies on the biochemical mechanism of dithiolane S-oxygenation in liver, kidney, and lung microsomes suggest that this reaction is catalyzed in a diastereoselective and enantioselective fashion by the flavin-containing monooxygenase and, to a lesser extent, the cytochromes P-450. This conclusion is based on results examining the effects of selective cytochrome P-450 inhibitors and positive effectors, microsome heat-inactivation treatment, and alternate substrates for the flavin-containing monooxygenase. Liver and kidney microsomes prepared from ovarectomized female rats tended to have decreased S-oxygenase activity, compared with nonpretreated female rats, whereas ovarectomized rats pretreated with estradiol had markedly lower S-oxygenase activity. In contrast, lung microsomal S-oxygenase activity, which is low in pulmonary microsomes from nonpretreated female rats, increases 2-4-fold after ovariectomization and estradiol pretreatment. In female Sprague-Dawley rats, estradiol pretreatment is mainly responsible for the large decrease (or increase) in S-oxygenase activity observed in the tissues examined, although it is unlikely that estradiol alone controls flavin-containing monooxygenase S-oxygenase activity. PMID:2304455

  3. Effect of nicardipine combined with esmolol on systemic and tissue oxygenation during off-pump coronary artery bypass grafting surgery

    Institute of Scientific and Technical Information of China (English)

    WANG Tian-long; JIANG Yan; YANG Ba-xian

    2005-01-01

    Background The hemodynamics and oxygenation severely fluctuated during the off-pump coronary artery bypass grafting (OPCABG). This study aimed at investigating whether or not nicardipine combined with esmolol (1∶ 10) can maintain systemic and tissue oxygenation during OPCABG.Methods Twenty patients scheduled for OPCABG were divided ramdomly into Group nicardipine (N) and Group nitroglycerine (X) respectively combined with esmolol (E) (Dosage ratio: 1 to 10) (Group N+E and Group X+E) with 10 patients in each group. The mixed solution of N+E or X+E were titrated to maintain mean arterial blood pressure between 70 and 80 mmHg following anesthesia induction. The variables of hemodynamics, arterial blood lactate content (Lac) and gastric intramucosal partial pressure of carbon dioxide were measured at the following time points: after induction of anesthesia (T1), pre-revascularization (T2), grafting of left anterior descending (T3), right coronary descending (T4) and left coronary circumflexus branches (T5), post-revascularization (T6), the end of operation (T7). The delivery of oxygen (DO2), consumption of oxygen (VO2) and gastric intramucosal pH (pHi) were calculated.Results The cardiac index (CI) in Group N+E was significantly increased (P<0.05) as compared with T1 during OPCABG, while it was mildly decreased in Group X+E. The stroke volumes at T4, T5 in Group N+E and at T3-T6 in Group X+E were significantly decreased (P<0.05). The systemic vascular resistance indices in Group N+E were significantly decreased as compared with T1 (P<0.05). The heart rates in these two Groups were significantly elevated intraoperatively (P<0.05). The DO2 after the infusion of N+E was significantly increased (P<0.05) or leveled to T1, and the Lac were within the normal range. But the DO2 in Group X+E was decreased throughout the procedure, reaching significant level at T5 (P<0.05), and the Lac was significantly increased beyond normal range (P<0.05). The pHi in Group N+E was

  4. Effect of ultraviolet blood irradiation and oxygenation on nerve function and function of the red blood cell membrane pump in patients with acute cerebral infarction

    Institute of Scientific and Technical Information of China (English)

    Jiaquan Wang; Chun Mao; Kaifu Ma; Shiqing Wang

    2006-01-01

    BACKGROUND: Ultraviolet blood irradiation and oxygenation (UBIO) has obtained better clinical effect in treating acute cerebral infarction, but the mechanism underlying this effect remains unclear.OBJECTIVE: To observe the effect of UBIO on the nerve function and activities of K+-Na+-ATPase and Ca2+-Mg2+-ATPase activities on the red blood cell (RBC) membrane of patients with acute cerebral infarction.DESIGN: A randomized and controlled study.SETTING: Department of Neurology, Xiangfan Central Hospital.PARTICIPANTS: From January 2000 to December 2001, excluding those above 70 years old, 58 cases of 700 patients with acute cerebral infarction admitted in the Department of Neurology, Xiangfan Central Hospital, were recruited and divided into two groups according to the random number table: UBIO treated group (n=28), including 17 males and 11 females, aged 40-68 years; and control group (n=30), including 20males and 10 females, aged 44-69 years. All the patients agreed to participate in the therapeutic program and detected items. The general informations were comparable without obvious differences between the two groups (P > 0.05).METHODS: ① The patients in both groups received routine treatments, besides, those in the UBIO treated group were given UBIO treatment by using the XL-200 type therapeutic apparatus produced in Shijiazhuang, whose ultraviolet wave was set at 253.7 nm with the energy density of 0.568 J/m2 per second, UBIO treatment started from the second day after admission, once every other day, with a single course consisting of 5-7 treatments. ② In the UBIO treated group, the venous blood was sampled before and after the first, third and the completion of the treatment course respectively, the venous blood was taken at each corresponding time point in the control group. After centrifugation of the blood at 10 000 rounds per minute,the RBC membrane was separated and then the activities of K+-Na+-ATPase and Ca2+-Mg2+-ATPase were detected by means of

  5. Improved cerebral oxygenation response and executive performance as a function of cardiorespiratory fitness in older women: a fNIRS study

    Directory of Open Access Journals (Sweden)

    Cédric T Albinet

    2014-10-01

    Full Text Available Cardiorespiratory fitness has been shown to protect and enhance cognitive and brain functions, but little is known about the cortical mechanisms that underlie these changes in older adults. In this study, functional NIRS was used to investigate variations in oxyhemoglobin ([HbO2] and in deoxyhemoglobin ([HHb] in the dorsolateral prefrontal cortex (DLPFC during the performance of an executive control task in older women with different levels of cardiorespiratory fitness (VO2max. Thirty-four women aged 60-77 years were classified as high-fit and low-fit based on VO2max measures. They all performed a control counting task and the Random Number Generation (RNG task at two different paces (1 number / 1 s and 1 number / 1.5 s, allowing to manipulate task difficulty, while hemodynamic responses in the bilateral DLPFCs were recorded using continuous-wave NIRS. The behavioral data revealed that the high-fit women showed significantly better performance on the RNG tasks compared with the low-fit women. The high-fit women showed significant increases in [HbO2] responses in both left and right DLPFCs during the RNG task, while the low-fit women showed significantly less activation in the right DLPFC compared with the right DLPFC of the high-fit women and compared with their own left DLPFC. At the level of the whole sample, increases in the [HbO2] responses in the right DLPFC were found to mediate in part the relationship between VO2max level and executive performance during the RNG task at 1.5 s but not at 1 s. These results provide support for the cardiorespiratory fitness hypothesis and suggest that higher levels of aerobic fitness in older women are related to increased cerebral oxygen supply to the DLPFC, sustaining better cognitive performance.

  6. Tuberculoma cerebral Cerebral tuberculoma

    OpenAIRE

    ELIZABETH CLARA BARROSO; TÂNIA REGINA BRÍGIDO DE OLIVEIRA; ANA MARIA DANTAS DO AMARAL; VALÉRIA GÓES FERREIRA PINHEIRO; ANA LÚCIA DE OLIVEIRA SOUSA

    2002-01-01

    Relata-se o caso de paciente com crises convulsivas de início recente. A tomografia computadorizada cerebral evidenciou imagem sugestiva de lesão expansiva metastática frontoparietal direita. A investigação de tumor primário ou outra doença foi negativa e o exame histopatológico do tecido cerebral diagnosticou tuberculoma. As convulsões foram controladas com a associação de hidantoína 300mg/dia ao esquema específico, utilizado por 18 meses. A tuberculose do sistema nervoso central representa ...

  7. Cerebral haematocrit measurement

    International Nuclear Information System (INIS)

    Regional cerebral haematocrit was measured in a group of sixteen subjects by the single-photon emission computerized tomography method. This group included three normal subjects as controls and thirteen patients affected with ischaemic cerebral disease presenting clinically with transient ischaemic attacks-six patients - or recent cerebral stroke - seven patients. Two intravenous radioactive tracers - technetium-99m labelled autologous red blood cells and Tc-99m human serum albumin were used. Cerebral tomographic imaging was performed using a rotating scintillation camera. The values of cerebral haematocrit obtained, taken as a ratio to venous haematocrit, range between 0.65-0.88 in the subjects studied. As a general finding in normal subjects and in patients with transient ischaemic attacks, no significant difference between right and left hemispheric haematocrit value was noted. However, in the group of patients affected with stroke, a significant difference in the right versus left hemispheric Hct was observed in 3 patients, the higher Hct value corresponding to the affected side. The clinical implication is on the emphasis of cerebral Hct measurement when the measurement of cerebral blood flow or volume is sought. Also the variation in regional Hct value observed in patients with stroke, above mentioned, points to a regulation mechanism of the blood composition for optimal oxygen delivery to the brain that is impaired in these patients. 14 refs. (Author)

  8. Effect of Immediate Hyperbaric Oxygen on Infarct Size in Rats after Focal Cerebral Ischemia%即时高压氧对大鼠局灶性脑缺血后梗死体积的影响

    Institute of Scientific and Technical Information of China (English)

    李纲; 张志强; 张立新

    2015-01-01

    目的:探讨即时高压氧对大鼠局灶性脑缺血后梗死体积的影响。方法 Sprague-Dawly大鼠随机分成对照组(n=9)、高压空气组(n=9)、高压氧组(n=9)、假手术组(n=5),前三组应用线栓法制作大鼠局灶性脑缺血模型,高压空气组、高压氧组在高压氧舱内造模,高压氧组于造模后立即行高压氧治疗。各组大鼠均于术后6h断头取脑,计算各组大鼠脑梗死占脑总体积百分比。结果与对照组相比,高压氧组及高压空气组梗死百分比均显著减少(P<0.001),高压氧组减少得更显著(P<0.001)。结论即时高压氧治疗能够降低大鼠脑局灶性缺血后梗死体积。%Objective To investigate the effect of immediate hyperbaric oxygen on focal cerebral ischemia of rats. Methods Sprague-Dawly rats were randomly divided into control group (n=9), hyperbaric air group (n=9), hyperbaric oxygen group (n=9) and sham group (n=5). The middle cerebral arteries were occluded in the former 3 groups, while the hyperbaric air group and the hyperbaric oxygen group operated in the hyperbaric chamber, and the hyperbaric oxygen group accepted hyperbaric oxygen immediately after operation. All the rats were sacrificed 6 hours after operation and the percentage of volume of infarction in the brain slices was calculated. Results The per-centage of infarction decreased in both hyperbaric oxygen group and hyperbaric air group compared with the control group (P<0.001), and decreased more in the hyperbaric oxygen therapy than in the hyperbaric air group (P<0.001). Conclusion Immediate hyperbaric oxygen ther-apy can reduce infarct size in rats after focal cerebral ischemia.

  9. Potato chip intake increases ascorbic acid levels and decreases reactive oxygen species in SMP30/GNL knockout mouse tissues.

    Science.gov (United States)

    Kondo, Yoshitaka; Sakuma, Rui; Ichisawa, Megumi; Ishihara, Katsuyuki; Kubo, Misako; Handa, Setsuko; Mugita, Hiroyuki; Maruyama, Naoki; Koga, Hidenori; Ishigami, Akihito

    2014-09-24

    Potato chips (PC) contain abundant amounts of the free radical scavenger ascorbic acid (AA) due to the rapid dehydration of potato tubers (Solanum tuberosum) that occurs during frying. To evaluate the antioxidant activity of PC, this study examined reactive oxygen species (ROS) levels in tissues from SMP30/GNL knockout (KO) mice that cannot synthesize AA and determined AA and ROS levels after the animals were fed 20 and 10% PC diets for 7 weeks. Compared with AA-sufficient mice, AA-depleted SMP30/GNL KO mice showed high ROS levels in tissues. SMP30/GNL KO mice fed a PC diet showed high AA and low ROS levels in the brain, heart, lung, testis, soleus muscle, plantaris muscle, stomach, small intestine, large intestine, eyeball, and epididymal fat compared with AA-depleted mice. The data suggest that PC intake increases AA levels and enhances ROS scavenging activity in tissues of SMP30/GNL KO mice, which are a promising model for evaluating the antioxidant activity of foods. PMID:25180784

  10. Acute hypoxia increases the cerebral metabolic rate

    DEFF Research Database (Denmark)

    Vestergaard, Mark Bitsch; Lindberg, Ulrich; Aachmann-Andersen, Niels Jacob;

    2016-01-01

    imaging techniques were used to measure global cerebral blood flow and the venous oxygen saturation in the sagittal sinus. Global cerebral metabolic rate of oxygen was quantified from cerebral blood flow and arteriovenous oxygen saturation difference. Concentrations of lactate, glutamate, N......-acetylaspartate, creatine and phosphocreatine were measured in the visual cortex by magnetic resonance spectroscopy. Twenty-three young healthy males were scanned for 60 min during normoxia, followed by 40 min of breathing hypoxic air. Inhalation of hypoxic air resulted in an increase in cerebral blood flow of 15.5% (p = 0.......058), and an increase in cerebral metabolic rate of oxygen of 8.5% (p = 0.035). Cerebral lactate concentration increased by 180.3% ([Formula: see text]), glutamate increased by 4.7% ([Formula: see text]) and creatine and phosphocreatine decreased by 15.2% (p[Formula: see text]). The N-acetylaspartate concentration...

  11. Comparison of regional skeletal muscle tissue oxygenation in college athletes and sedentary control subjects using quantitative BOLD MR imaging.

    Science.gov (United States)

    Stacy, Mitchel R; Caracciolo, Christopher M; Qiu, Maolin; Pal, Prasanta; Varga, Tyler; Constable, Robert Todd; Sinusas, Albert J

    2016-08-01

    Blood oxygen level-dependent (BOLD) magnetic resonance (MR) imaging permits noninvasive assessment of tissue oxygenation. We hypothesized that BOLD imaging would allow for regional evaluation of differences in skeletal muscle oxygenation between athletes and sedentary control subjects, and dynamic BOLD responses to ischemia (i.e., proximal cuff occlusion) and reactive hyperemia (i.e., rapid cuff deflation) would relate to lower extremity function, as assessed by jumping ability. College football athletes (linemen, defensive backs/wide receivers) were compared to sedentary healthy controls. BOLD signal of the gastrocnemius, soleus, anterior tibialis, and peroneus longus was assessed for peak hyperemic value (PHV), time to peak (TTP), minimum ischemic value (MIV), and time to recovery (TTR). Significantly higher PHVs were identified in athletes versus controls for the gastrocnemius (linemen, 15.8 ± 9.1%; defensive backs/wide receivers, 17.9 ± 5.1%; controls, 7.4 ± 3.5%), soleus (linemen, 25.9 ± 11.5%; backs/receivers, 22.0 ± 9.4%; controls, 12.9 ± 5.8%), and anterior tibialis (linemen, 12.8 ± 5.3%; backs/receivers, 12.6 ± 3.9%; controls, 7.7 ± 4.0%), whereas no differences in PHV were found for the peroneus longus (linemen, 14.1 ± 6.9%; backs/receivers, 11.7 ± 4.6%; controls, 9.0 ± 4.9%). In all subject groups, the gastrocnemius and soleus muscles exhibited the lowest MIVs during cuff occlusion. No differences in TTR were found between muscles for any subject group. PHV of the gastrocnemius muscle was significantly and positively related to maximal vertical (r = 0.56, P = 0.002) and broad jump (r = 0.47, P = 0.01). These results suggest that BOLD MR imaging is a useful noninvasive tool for evaluating differences in tissue oxygenation of specific muscles between active and sedentary individuals, and peak BOLD responses may relate to functional capacity. PMID:27535483

  12. Noninvasive cerebral hemoglobin oxygenation quantification of fetal sheep under hypoxic stress in utero using frequency-domain diffuse optical two-layer model

    Science.gov (United States)

    Choe, Regine; Durduran, Turgut; Yu, Guoqiang; Nijland, Mark J. M.; Nathanielsz, Peter W.; Chance, Britton; Yodh, Arjun G.; Ramanujam, Nirmala

    2003-07-01

    A study using pregnant sheep was designed to simulate fetal hypoxia in order to investigate the ability of near-infrared spectroscopy (NIRS) to detect and quantify fetal hypoxia in utero. The near-infrared spectroscopic probe consisted of two detectors and six source positions. It was placed on the maternal ewe abdomen above the fetal head. The light sources were modulated at 70 MHz and frequency-encoded so that simultaneous measurements at 675, 786, 830 nm for each source position were possible. After the baseline measurements, fetal hypoxia was induced by blocking the aorta of pregnant ewe and thus compromising the blood supply to the uterus. Blood gas samples were concurrently drawn from the fetal brachial artery and jugular veins. Analysis of the diffuse optical data used a two-layer model to separate the maternal layer from the fetal head. The analysis also employed a priori spectral information about tissue chromophores. This approach provided good quantification of blood oxygenation changes, which correlated well with the blood gas analyses. By contrast the homogeneous model underestimated oxygenation changes during hypoxia.

  13. Cerebral cysticercosis

    International Nuclear Information System (INIS)

    Two cases of histologically proven cerebral cysticercosis are presented. In both cases subcutaneous tissue nodules, a rare feature, were present. Several disease patterns are apparent - meningeal, parenchymatous and ventricular, spinal cord lesions and mixed patterns. Epilepsy is by far the major presenting symptom of cysticercosis, which in turn plays a significant role in the causation of adult-onset epilepsy in Blacks. Despite its drawbacks, the haemag-glutination inhibition test remains the most satisfactory serological method at present available for the diagnosis of cysticercosis; it is positive in up to 85% of cases of proven cysticercosis. With the advent of computed tomography many cases of unsuspected cysticercosis (symptomatic or asymptomatic) are being discovered

  14. Cerebral circulation and metabolism in cerebral infarction of middle cerebral artery territory

    International Nuclear Information System (INIS)

    Regional cerebral blood flow (rCBF), oxygen metabolism (rCMRO2), oxygen extraction fraction (rOEF) and blood volume (rCBV) were measured with a high performance positron CT (HEADTOME-III) and the 15O labeled gas steady-state method. Seven normal volunteers and 13 patients with ischemic infarction located in the territory of unilateral middle cerebral artery (MCA) were subjected to the positron CT measurement. In the present study, over estimation of rOEF and rCMRO2 were corrected by rCBV using the principle described by Lammertsma and Jones. From these paremeters we also calculated an rCBV/rCBF which meant regional blood transient time of cerebral vessels (rTT). Early ischemic lesions showed two types of uncoupling between rCBF and rCMRO2. Patients studied within the 5th day of the onset showed high rOEF with low rCBF in the infarcted forcus (misery perfusion). About a week after onset rOEF was changed into low level with decreased rCMRO2 and recovered rCBF, and the change lasted to a month after onset recovered rCBF, and the change lasted to a month after onset (luxury perfusion). Then, about two months later, the lesions gradually went to matched change of rCBF and rCMRO2 (coupled perfusion). These changes of rCBF and rCMRO2 described above will reveal the natural course of ischemic brain tissue with acute onset. It was also proved that there was positive correlation between rTT and rOEF. A parameter of rTT will be important to presume rOEF from a single photon emission CT measurement, which has not been able to study oxygen metabolism but could measure rCBF and rCBV. The threshold levels of rCBF and rCMRO2 for morphological tissue damages assessed as a low density area on a X-ray CT were clinically estimated from the present study. The thresholds evaluated in patients within a day of onset, were 12 ml/100 ml/min, and 1.5 ml/ 100 ml/min for rCBF and rCMRO2, respectively. (J.P.N.)

  15. Hyperventilation, cerebral perfusion, and syncope

    DEFF Research Database (Denmark)

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

    2014-01-01

    dioxide (PaCO2) and oxygen (PaO2) partial pressures so that hypercapnia/hypoxia increases and hypocapnia/hyperoxia reduces global cerebral blood flow. Cerebral hypoperfusion and TLOC have been associated with hypocapnia related to HV. Notwithstanding pronounced cerebrovascular effects of PaCO2 the......This review summarizes evidence in humans for an association between hyperventilation (HV)-induced hypocapnia and a reduction in cerebral perfusion leading to syncope defined as transient loss of consciousness (TLOC). The cerebral vasculature is sensitive to changes in both the arterial carbon...... contribution of a low PaCO2 to the early postural reduction in middle cerebral artery blood velocity is transient. HV together with postural stress does not reduce cerebral perfusion to such an extent that TLOC develops. However when HV is combined with cardiovascular stressors like cold immersion or reduced...

  16. A stereotaxic, population-averaged T1w ovine brain atlas including cerebral morphology and tissue volumes

    OpenAIRE

    Nitzsche, Björn; Frey, Stephen; Collins, Louis D.; Seeger, Johannes; Lobsien, Donald; Dreyer, Antje; Kirsten, Holger; Stoffel, Michael H.; Fonov, Vladimir S.; Boltze, Johannes

    2015-01-01

    Standard stereotaxic reference systems play a key role in human brain studies. Stereotaxic coordinate systems have also been developed for experimental animals including non-human primates, dogs, and rodents. However, they are lacking for other species being relevant in experimental neuroscience including sheep. Here, we present a spatial, unbiased ovine brain template with tissue probability maps (TPM) that offer a detailed stereotaxic reference frame for anatomical features and localization...

  17. A stereotaxic, population-averaged T1w ovine brain atlas including cerebral morphology and tissue volumes

    OpenAIRE

    Björn Nitzsche; Stephen Frey; Johannes Seeger; Donald Lobsien; Antje Dreyer; Holger Kirsten; Stoffel, Michael H.; Johannes Boltze

    2015-01-01

    Standard stereotaxic reference systems play a key role in human brain studies. Stereotaxic coordinate systems have also been developed for experimental animals including non-human primates, dogs and rodents. However, they are lacking for other species being relevant in experimental neuroscience including sheep. Here, we present a spatial, unbiased ovine brain template with tissue probability maps (TPM) that offer a detailed stereotaxic reference frame for anatomical features and localization ...

  18. Hyperbaric oxygen therapy in the treatment of radio-induced lesions in normal tissues: a literature review

    International Nuclear Information System (INIS)

    Late complications are one of the major factors limiting radiotherapy treatment, and their treatment is not codified. Hyperbaric oxygen (HBO) has been used in combination with radiotherapy for over half a century, either to maximise its effectiveness or in an attempt to treat late complications. In this latter case, retrospective trials and case reports are prevailing in literature. This prompted European Society for Therapeutic Radiotherapy and Oncology and European Committee for Hyperbaric Medicine to organise a consensus conference in October 2001, dealing with the HBO indications on radiotherapy for the treatment and prevention of late complications. This updated literature review is part of the documents the jury based its opinion on. A systematic search was done on literature from 1960 to 2004, by only taking into account the articles that appeared in peer review journals. Hyperbaric oxygen treatment involving complications to the head and neck, pelvis and nervous system, and the prevention of complications after surgery in irradiated tissues have been studied. Despite the small number of controlled trials, it may be indicated for the treatment of mandibular osteoradionecrosis in combination with surgery, haemorrhagic cystitis resistant to conventional treatments and the prevention of osteoradionecrosis after dental extraction, whose level of evidence seems to be the most significant though randomised trials are still necessary. The other treatment methods are also outlined for each location

  19. Cerebral Palsy. Fact Sheet = La Paralisis Cerebral. Hojas Informativas Sobre Discapacidades.

    Science.gov (United States)

    National Information Center for Children and Youth with Disabilities, Washington, DC.

    This fact sheet on cerebral palsy is written in both English and Spanish. First, it provides a definition of cerebral palsy and considers various causes (e.g., an insufficient amount of oxygen reaching the fetal or newborn brain). The fact sheet then offers incidence figures and explains characteristics of the three main types of cerebral palsy:…

  20. Cerebral Palsy

    Science.gov (United States)

    Cerebral palsy is a group of disorders that affect a person's ability to move and to maintain balance ... do not get worse over time. People with cerebral palsy may have difficulty walking. They may also have ...

  1. A stereotaxic, population-averaged T1w ovine brain atlas including cerebral morphology and tissue volumes

    Directory of Open Access Journals (Sweden)

    Björn eNitzsche

    2015-06-01

    Full Text Available Standard stereotaxic reference systems play a key role in human brain studies. Stereotaxic coordinate systems have also been developed for experimental animals including non-human primates, dogs and rodents. However, they are lacking for other species being relevant in experimental neuroscience including sheep. Here, we present a spatial, unbiased ovine brain template with tissue probability maps (TPM that offer a detailed stereotaxic reference frame for anatomical features and localization of brain areas, thereby enabling inter-individual and cross-study comparability. Three-dimensional data sets from healthy adult Merino sheep (Ovis orientalis aries, 12 ewes and 26 neutered rams were acquired on a 1.5T Philips MRI using a T1w sequence. Data were averaged by linear and non-linear registration algorithms. Moreover, animals were subjected to detailed brain volume analysis including examinations with respect to body weight, age and sex. The created T1w brain template provides an appropriate population-averaged ovine brain anatomy in a spatial standard coordinate system. Additionally, TPM for gray (GM and white (WM matter as well as cerebrospinal fluid (CSF classification enabled automatic prior-based tissue segmentation using statistical parametric mapping (SPM. Overall, a positive correlation of GM volume and body weight explained about 15% of the variance of GM while a positive correlation between WM and age was found. Absolute tissue volume differences were not detected, indeed ewes showed significantly more GM per bodyweight as compared to neutered rams. The created framework including spatial brain template and TPM represent a useful tool for unbiased automatic image preprocessing and morphological characterization in sheep. Therefore, the reported results may serve as a starting point for further experimental and/or translational research aiming at in vivo analysis in this species.

  2. Fuzzy segmentation of cerebral tissues in a 3-D MR image: a possibilistic approach versus other methods

    International Nuclear Information System (INIS)

    An algorithm for the segmentation of a single sequence of 3-D magnetic resonance images into cerebrospinal Fluid (CSF), Grey (GM) and White Matter (WM) classes is proposed. The method is a possibilistic clustering algorithm on the wavelet coefficients of the voxels. Possibilistic logic allows for modeling the uncertainty and the impreciseness inherent in MR images of the brain, while the wavelet representation allows to take into account both spatial and textural information. The procedure is fast, unsupervised and totally independent of statistical assumptions. In method is validated on a phantom, and then compared with other very used brain tissues segmentation algorithms. (authors)

  3. Tumour oxygenation assessed by polarographic needle electrodes and bioenergetic status measured by 31P magnetic resonance spectroscopy im human soft tissue tumours

    International Nuclear Information System (INIS)

    The purpose of this study was to evaluate the feasibility of polarographic oxygen electrode measurements and phosphorus magnetic resonance spectroscopy (31P-MRS) in extravisceral soft tissue tumours, designated to receive preoperative radiotherapy. Pretreatment tumour oxygenation was determined in 41 cases and 31P-MRS was amenable to lesions in 34 patients. Biopsies were characterized histopathologically as 25 primary soft tissue sarcomas (STS), 2 recurrent STS, 9 benign and 5 other malignancies. Evaluation of phosphorus (31P) spectra was possible in 11 cases. The oxygenation status of normal tissue was higher than that of tumours, whereas no difference was found between oxygenation status of benign lesions and that of STS. There was substantial variation between tumours in the median pO2 and the bioenergetic status (β-NTP/Pi). No correlation was found between tumour pO2 and volume (n=25). Moreover, there was no correlation between β-NTP/Pi and the median tumour pO2, the fraction of pO2 values ≤2.5 mm Hg or tumour volume (n=10), respectively. In conclusion, oxygen electrode assessment was found to be a clinically applicable and feasible technique for measuring tumour oxygenation status, whereas the success of 31P-MRS in human neoplasms was limited by a very poor resolution in the phosphorus signal that allowed analysis of 31P spectra in 11 tumours out of 34 cases. (orig.)

  4. Crew Cerebral Oxygen Monitor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Phase I SBIR proposal is aimed at developing a non-invasive, optical method for monitoring the state of consciousness of crew members in operational...

  5. Crew Cerebral Oxygen Monitor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Phase II SBIR proposal is aimed at developing a non-invasive, optical method for monitoring crew member state of awareness in operational environments. All...

  6. Cerebral Atrophy

    Science.gov (United States)

    ... Alzheimer’s disease, Pick’s disease, and fronto-temporal dementia cerebral palsy , in which lesions (damaged areas) may impair motor ... lead to cerebral atrophy. NIH Patient Recruitment for Cerebral Atrophy Clinical Trials ... by: Office of Communications and Public Liaison National Institute of Neurological Disorders ...

  7. 不同时间窗及疗程的高压氧治疗对急性脑梗死的影响%Influence of Acute Cerebral Infarction and Treatment of Different Time Windows Hyperbaric Oxygen Therapy

    Institute of Scientific and Technical Information of China (English)

    潘红伟

    2016-01-01

    Objective To investigate the effect of hyperbaric oxygen on acute cerebral infarction in different time windows and treatment. Methods 112 patients with acute cerebral infarction were divided into four groups according to the time window and the course of treatment, 28 cases in each group. After hyperbaric oxygen therapy, the daily activity of daily living (ADL) score and EEG were examined and compared between groups. Result The same line course of hyperbaric oxygen therapy, hyperbaric oxygen therapy sooner, the patient's activities of daily living (ADL) score and EEG better result, the difference was statistically significant (P<0.05). Conclusion Hyperbaric oxygen therapy time window has an important influence on the treatment of first onset of acute cerebral infarction patients, the early treatment time is better, with the incidence of 24 h after treatment with hyperbaric oxygen therapy, 24-72 h within the efficacy of intervention, more than 72 h.%目的:探讨不同时间窗及疗程的高压氧对急性脑梗死疗效的影响。方法对我院2013年7月至2015年1月间接治的112例急性脑梗死患者按从发病到高压氧治疗的时间窗及疗程分为四组,每组28例。对各组患者在高压氧治疗后分别进行日常生活活动能力(ADL)评分及脑电图检查,并进行各组之间的比较。结果在行同样疗程的高压氧治疗中,越早进行高压氧治疗,患者的日常生活活动能力(ADL)评分及脑电图结果越好,差异有统计学意义(P<0.05)。结论高压氧治疗时间窗对首次发病的急性脑梗死患者疗效具有重要影响,开始治疗时间越早则疗效越佳,以发病后24 h 内行高压氧治疗疗效最佳,24~72 h 内干预则疗效次之,超过72 h 则疗效大幅降低。

  8. RBC-coupled tPA prevents cerebrovasodilatory impairment and tissue injury in pediatric cerebral hypoxia/ischemia through inhibition of ERK MAPK unregulation

    Energy Technology Data Exchange (ETDEWEB)

    Ganguly, Kumkum [Los Alamos National Laboratory; Armstead, William M [U PENNSYLVANIA; Kiessling, J W [U PENNSYLVANIA; Chen, Xiao - Han [U PENNSYLVANIA; Smith, Douglas H [U PENNSYLVANA; Higazi, Abd Ar [U PENNSYLVANIA; Cines, Douglas B [U PENNSYLVANIA; Bdeir, Khalil [U PENNSYLVANIA; Zaitsev, Sergei [U PENNSYLVANIA; Muzykantov, Vladimir R [U PENNSYLVANIA

    2008-01-01

    Babies experience hypoxia (H) and ischemia (I) from stroke. The only approved treatment for stroke is fibrinolytic therapy with tissue-type plasminogen activator (tPA). However, tPA potentiates H/I-induced impairment of responses to cerebrovasodilators such as hypercapnia and hypotension, and blockade of tPA-mediated vasoactivity prevents this deleterious effect. Coupling tPA to RBCs reduces its CNS toxicity through spatially confining the drug to the vasculature. Mitogen activated protein kinase (MAPK), a family of at least 3 kinases, is upregulated after H/I. In this study we determined if RBC-tPA given before or after cerebral H/I would preserve responses to cerebrovasodilators and prevent neuronal injury mediated through the ERK MAPK pathway. Animals given RBC-tPA maintained responses to cerebrovasodilators at levels equivalent to pre-H/I values. CSF and brain parenchymal ERK MAPK was elevated by H/I and this upregulation was potentiated by tPA, but blunted by RBC-tPA. U 0126, an ERK MAPK antagonist, also maintained cerebrovasodilation post H/I. Neuronal degeneration in CA1 hippocampus and parietal cortex after H/I was exacerbated by tPA, but ameliorated by RBC-tPA and U 0126. These data suggest that coupling tPA to RBCs may offer a novel approach towards increasing the benefit/risk ratio of thrombolytic therapy for CNS disorders associated with H/I.

  9. Non-invasive assessment of cerebral microcirculation with diffuse optics and coherent hemodynamics spectroscopy

    Science.gov (United States)

    Fantini, Sergio; Sassaroli, Angelo; Kainerstorfer, Jana M.; Tgavalekos, Kristen T.; Zang, Xuan

    2016-03-01

    We describe the general principles and initial results of coherent hemodynamics spectroscopy (CHS), which is a new technique for the quantitative assessment of cerebral hemodynamics on the basis of dynamic near-infrared spectroscopy (NIRS) measurements. The two components of CHS are (1) dynamic measurements of coherent cerebral hemodynamics in the form of oscillations at multiple frequencies (frequency domain) or temporal transients (time domain), and (2) their quantitative analysis with a dynamic mathematical model that relates the concentration and oxygen saturation of hemoglobin in tissue to cerebral blood volume (CBV), cerebral blood flow (CBF), and cerebral metabolic rate of oxygen (CMRO2). In particular, CHS can provide absolute measurements and dynamic monitoring of CBF, and quantitative measures of cerebral autoregulation. We report initial results of CBF measurements in hemodialysis patients, where we found a lower CBF (54 +/- 16 ml/(100 g-min)) compared to a group of healthy controls (95 +/- 11 ml/(100 g-min)). We also report CHS measurements of cerebral autoregulation, where a quantitative index of autoregulation (its cutoff frequency) was found to be significantly greater in healthy subjects during hyperventilation (0.034 +/- 0.005 Hz) than during normal breathing (0.017 +/- 0.002 Hz). We also present our approach to depth resolved CHS, based on multi-distance, frequency-domain NIRS data and a two-layer diffusion model, to enhance sensitivity to cerebral tissue. CHS offers a potentially powerful approach to the quantitative assessment and continuous monitoring of local brain perfusion at the microcirculation level, with prospective brain mapping capabilities of research and clinical significance.

  10. Acupressure at the Meridian Acupoint Xiyangguan (GB33) Influences Near-Infrared Spectroscopic Parameters (Regional Oxygen Saturation) in Deeper Tissue of the Knee in Healthy Volunteers

    OpenAIRE

    Gerhard Litscher; Michael Ofner; Wei He; Lu Wang; Ingrid Gaischek

    2013-01-01

    Up to now, it is still unknown whether microcirculation of deeper peripheral tissue (knee) can be modulated by acupuncture or acupressure on a meridian acupoint. The goal of this pilot study was to investigate possible effects of acupressure at the Xiyangguan acupoint (GB33) on the regional oxygen saturation of the deeper knee tissues by near-infrared spectroscopy (NIRS). Twelve healthy volunteers with a mean age of 23.8 ± 1.6 years were investigated. Acupressure stimulation was performed for...

  11. Perfusion MRI in cerebral infarction

    International Nuclear Information System (INIS)

    Purpose: To investigate the hemodynamic changes in patients with acute cerebral stroke by perfusion MRI. Materials and methods: In 12 patients with acute stroke in the territory of the middle cerebral artery, perfusion MRI was performed. Peak time, mean transit time, regional cerebral blood volume and regional cerebral blood flow were calculated in the infarction, the peri-infarction area and the contralateral hemisphere. Results: In the infarction the mean blood flow was 29 ml/100 g/min, compared to about 40 ml/100 g/min in the peri-infarction area and the contralateral hemisphere. In two patients increased cortical blood flow was found in the infarction due to luxury perfusion. The cerebral blood volume was reduced in the infarction, but significantly increased, to 7.3 ml/100 g, in the peri-infarction tissue. Conclusion: Perfusion MRI allows one to differentiate various patterns of perfusion disorders in patients with acute cerebral stroke. (orig./AJ)

  12. Effect analysis on hyperbaric oxygen in treating infants and young children with cerebral palsy%高压氧治疗婴幼儿脑瘫的疗效分析

    Institute of Scientific and Technical Information of China (English)

    闫斐; 邱萌

    2011-01-01

    目的 探讨高压氧治疗要幼儿脑瘫的效果.方法 选择90例脑瘫患儿随机分为治疗组及对照组,各45例;对照组采用常规药物治疗,治疗组在对照组基础上加用高压氧治疗.结果 治疗组治疗前后发育商评分和运动功能评分显著高于对照组(P<0.05);治疗组总有效率为91.1%,显著高于对照组的71.1%(P<0.05);治疗组在高压氧舱治疗过程中未发现眼型、肺型氧中毒的不良反应.结论 使用高压氧治疗要幼儿脑瘫能使患儿运动、言语、智力等功能达到最佳功能状态,且方法 简便、不良反应少,是减轻残疾的有效手段之一.%Objective To discuss the effect of hyperbaric oxygen t in treating infants and young children with cerebral palsy. Methods 90 cases of infants and young children with cerebral palsy were randomly divided into treatment group (n = 45) and con-trol group ( n = 45 ) , patients in control group received conventional therapy; patients in treatment group were added with hyperbaric oxygen on the basis of conventional therapy. Results After treatment, development quotient ( DQ) scores and motor function scores in treatment group were significantly higher than that in control group (P < 0.05 ) ; the total effective rate in treatment group was 91.1% , significantly higher than that in control group (71.1%), (P <0.05) ; No advene effects (ophthalmoretinal type and pulmonary type oxygen poisoning) were found during hyperbaric oxygen treatment in treatment group. Conclusion Use hyperbaric oxygen to treat infants and young children with cerebral palsy can makes the optimal functional status of movement, speech, mental function and other functions, it is simple, less adverse reactions and is one of the effective means to reduce disabilities.

  13. Effect of pre-ischemia on hypoxia-inducible factor expression in the brain tissue of rats with cerebral ischemia/reperfusion injury

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    BACKGROUND: Hypoxia-inducible factor 1 (HIF-1) can lead to the adaptative reaction of body for hypoxia and ischemia. HIF-1 plays an important role in the response of ischemia-hypoxia. At present, there has been no overall report on the significance for the expression of HIF-1 following experimental cerebral ischemia.OBJECTIVE: To observe the expression of HIF-1 after middle cerebral artery occlusion (MCAO) by immunohistochemical method.DESIGN: Completely randomly grouped controlled animal experiment.SETTING: Second Hospital, Xi'an Jiaotong University.MATERIALS: Thirty-six Sprague-Dawley healthy male rats, with body mass of 250 - 330 g, were used in this study. Thirty-six rats were randomized into 3 groups: pre-ischemia group, sham-operation group and control group, with 12 rats in each.METHODS: This study was carried out in the clinical laboratory, People's Hospital of Ningjin County of Shandong Province from March 2006 to January 2007. Rats in the pre-ischemia group were created into pre-ischemia models by two embolisms twice. Three days after ischemic preconditioning, middle cerebral artery (MCA) was occluded for 2 hours with the same method. After being perfused for 22 hours, the rats were euthanized. In the sham-operation group, rats were not given the treatment of pre-ischemia. In the first operation, only common carotid artery (CCA) and its crotch were exposed in the first operation, and MCA was not blocked by inserting embolism. At postoperative 3 days, rats were euthanized after being subjected to MCAO for 2 hours and reperfusion 22 hours by the same procedure as that in the pre-ischemia group. As for each rat in the control group, only CCA and its crotch were exposed, and no any other treatment was carried out on them.MAIN OUTCOME MEASURES: Brain tissue of each rat was performed immunohistochemical staining at reperfusion 22 hours after pre-ischemia, HIF-1 expression and brain infarct volume were detected.RESULTS: Thirty-six Sprague-Dawley rats were

  14. 组织细胞氧合障碍的机制及其对策%Mechanism and strategy of oxygenation dysfunction in tissue and cell levels

    Institute of Scientific and Technical Information of China (English)

    赵良

    2013-01-01

    According to theory of oxygen transport, mechanism of oxygenation dysfunction in tissue and cell levels can be divided into five types: low oxygen supply, high oxygen consumption, decreased oxygen extraction, oxygen utilization dysfunction and mixed pattern. Up to now, clinically corresponding strategy have been taken. Oxygen supply in global levels can be increased by blood transfusion, use of positive inotropic drugs, elevation of inspired oxygen fraction. Oxygen supply in tissue levels can be elevated by regulation of blood vessel tension, improvement of blood hemorheology. Oxygen consumption can be decreased by anesthesia, sedation, muscle relaxation, hypothermia and mechanical ventilation. Improvement of capillary permeability can increase oxygen uptake by enlargement in diffusion area of oxygen. On basis of osmotic pressure elevation, the edema eliminated by diuresis or dehydration can facilitate oxygen extraction through shortening diffusion distance of oxygen.%依据氧输送原理可以将组织细胞氧合障碍的机制划分为五种类型:①低氧供;②高氧耗;③氧摄取能力减退;④氧利用障碍;⑤混合型.迄今为止,临床上能够采取的相应对策有输血、应用正性肌力药物、提高吸氧浓度以增加系统水平氧供给,调节血管张力、改善血液流变学来增加组织水平氧供给.麻醉、镇静、肌肉松弛、降温和机械通气等措施降低氧耗;改善毛细血管通透性,通过扩大氧弥散面积,增加组织水平氧摄取;在提高胶体渗透压基础上利尿、脱水消除水肿,通过缩短氧弥散距离,易化组织水平氧摄取.

  15. Specificity of Compensatory Reserve and Tissue Oxygenation as Early Predictors of Tolerance to Progressive Reductions in Central Blood Volume.

    Science.gov (United States)

    Howard, Jeffrey T; Janak, Jud C; Hinojosa-Laborde, Carmen; Convertino, Victor A

    2016-09-01

    We previously reported that measurements of muscle oxygen saturation (SmO2) and the compensatory reserve index (CRI) provided earlier indication of reduced central blood volume than standard vital signs (e.g., blood pressure, heart rate, arterial oxygen saturation). In the present study, we hypothesized that the CRI would provide greater sensitivity and specificity to detect progressive decrease in central circulating blood volume compared with SmO2. Continuous noninvasive measures of CRI (calculated from feature changes in the photoplethysmographic arterial waveforms) were collected from 55 healthy volunteer subjects before and during stepwise lower body negative pressure (LBNP) to the onset of hemodynamic decompensation. Near infrared spectroscopy was used on the forearm to obtain deep SmO2, hydrogen ion concentration ([H]), and hemoglobin volume (HbT; decreases reflect vasoconstriction). CRI decreased by 97% in a linear fashion across progressive blood volume loss, with no clinically significant alterations in vital signs. The receiver operating characteristic (ROC) area under the curve (AUC) for the CRI was 0.91, with a sensitivity of 0.87 and specificity of 0.80, when predicting decompensation at progressive levels of LBNP. In comparison, SmO2, [H], and HbT had significantly lower ROC AUC, sensitivity and specificity values for detecting the same outcome. Consistent with our hypothesis, CRI detected central hypovolemia with significantly greater specificity than measures of tissue metabolism. Single measurement of CRI may enable more accurate triage, while CRI monitoring may allow for earlier detection of casualty deterioration. PMID:27058052

  16. Light-Addressable Measurement of in Vivo Tissue Oxygenation in an Unanesthetized Zebrafish Embryo via Phase-Based Phosphorescence Lifetime Detection

    Directory of Open Access Journals (Sweden)

    Shih-Hao Huang

    2015-04-01

    Full Text Available We have developed a digital light modulation system that utilizes a modified commercial projector equipped with a laser diode as a light source for quantitative measurements of in vivo tissue oxygenation in an unanesthetized zebrafish embryo via phase-based phosphorescence lifetime detection. The oxygen-sensitive phosphorescent probe (Oxyphor G4 was first inoculated into the bloodstream of 48 h post-fertilization (48 hpf zebrafish embryos via the circulation valley to rapidly disperse probes throughout the embryo. The unanesthetized zebrafish embryo was introduced into the microfluidic device and immobilized on its lateral side by using a pneumatically actuated membrane. By controlling the illumination pattern on the digital micromirror device in the projector, the modulated excitation light can be spatially projected to illuminate arbitrarily-shaped regions of tissue of interest for in vivo oxygen measurements. We have successfully measured in vivo oxygen changes in the cardiac region and cardinal vein of a 48 hpf zebrafish embryo that experience hypoxia and subsequent normoxic conditions. Our proposed platform provides the potential for the real-time investigation of oxygen distribution in tissue microvasculature that relates to physiological stimulation and diseases in a developing organism.

  17. Patterns and variability of tumor oxygenation in human soft tissue sarcomas, cervical carcinomas, and lymph node metastases

    International Nuclear Information System (INIS)

    Purpose: The validity of tumor pO2 measurement as a predictive outcome assay depends upon demonstrating that intrapatient pO2 variation is less than interpatient variation. No consensus exists regarding the appropriate distance between individual measurements. This distance could affect the calculation of the hypoxic fraction (% pO2s 2 heterogeneity in three different sets of patients. Materials and Methods: Fifteen patients with soft tissue sarcoma, nine patients with cervical carcinoma, and eight patients with squamous carcinoma metastatic to lymph nodes underwent pretreatment polarographic pO2 measurements. Two grossly distinct sites were studied in each tumor, and 2-3 linear tracks were measured at each site. Track lengths varied from 20-36 mm. Distance between measured points was either 0.7-0.8 mm or 0.4 mm. Mean pO2, median pO2, and hypoxic fraction were calculated for each track. Data for each patient were also averaged across all tracks obtained for that patient. Track-specific data were used to evaluate intrapatient variation. The range of average values for each patient was used to assess interpatient heterogeneity. The ratio of these measures provided an assessment of within- vs. between-patient heterogeneity. Results: The median number of pO2 measurements/patient was 200 (range: 88-356). The average length of hypoxic regions varied from 4.5-5.6 mm. Median tumor pO2s for the cervix, lymph node, and sarcoma patients were 4.5 mm Hg, 12.6 mm Hg, and 18.0 mm Hg, respectively (p = 0.07). Median hypoxic fractions were 0.61, 0.36, and 0.31, respectively (p = 0.07). Intrapatient heterogeneity was less than interpatient heterogeneity for all parameters in all patients, except for mean pO2 for the cervix patients measured at 0.7-mm increments (1.51). Assessment of oxygenation was not affected by the distance between samples. Conclusions: Heterogeneity of tumor oxygenation within tumors is less than that between tumors. Both 0.4 mm and 0.7-0.8 mm sampling

  18. Cytochrome c oxidase response to changes in cerebral oxygen delivery in the adult brain shows higher brain-specificity than haemoglobin

    OpenAIRE

    Kolyva, C; Ghosh, A.; Tachtsidis, I; Highton, D; Cooper, C E; Smith, M; Elwell, C. E.

    2014-01-01

    The redox state of cerebral mitochondrial cytochrome c oxidase monitored with near-infrared spectroscopy (Δ[oxCCO]) is a signal with strong potential as a non-invasive, bedside biomarker of cerebral metabolic status. We hypothesised that the higher mitochondrial density of brain compared to skin and skull would lead to evidence of brain-specificity of the Δ[oxCCO] signal when measured with a multi-distance near-infrared spectroscopy (NIRS) system. Measurements of Δ[oxCCO] as well as of concen...

  19. The effect of hyperbaric oxygen therapy on the nervous system. Systematic review

    OpenAIRE

    Kujawski Sławomir; Kujawska Agnieszka; Kozakiewicz Mariusz; Olszański Romuald; Siermontowski Piotr; Zalewski Paweł

    2015-01-01

    Hyperbaric oxygen therapy (HBOT) is found among the interests of researchers who seek new methods of treatment of diseases of the nervous system. An increase of the partial pressure of oxygen in arterial blood within the appropriate range leads to numerous changes in the cells of the brain tissue. In this paper we analyse the results of selected articles describing HBOT used on pathologies of the nervous system such as stroke, autism, multiple sclerosis and cerebral palsy as well as in the co...

  20. Radiation-induced DNA damage in tumors and normal tissues. II. Influence of dose, residual DNA damage and physiological factors in oxygenated cells

    International Nuclear Information System (INIS)

    Detection and quantification of hypoxic cells in solid tumors is important for many experimental and clinical situations. Several laboratories, including ours, have suggested that assays which measure radiation-induced DNA strand breaks and DNA-protein crosslinks (DPCs) might be used to detect or quantify hypoxic cells in tumors and normal tissues. Recently, we demonstrated the feasibility of using an alkaline elution assay that measures strand breaks and DPCs to detect and/or quantify hypoxic cells in tissues. For this approach to be valid, DPCs must not be formed to any great extent in irradiated oxygenated cells, and the formation and repair of strand breaks and DPCs in oxygenated cells must not be modified appreciably by physiological factors (e.g., temperature, pH and nutrient depletion) that are often found in solid tumors. To address these issues, two sets of experiments were performed. In one set of experiments, oxygenated 9L cells in tissue culture, subcutaneous 9L tumors and rat cerebella were irradiated with doses of 15 or 50 Gy and allowed to repair until the residual strand break damage was low enough to detect DPCs. In another set of experiments, oxygenated exponentially growing or plateau-phase 9L cells in tissue culture were irradiated with a dose of 15 Gy at 37 or 20 degrees C, while the cells were maintained at a pH of either 6.6 or 7.3. DNA-protein crosslinks were formed in oxygenated cells about 100 times less efficiently than in hypoxic cells. In addition, temperature, pH, nutrient depletion and growth phase did not appreciably alter the formation and repair of strand breaks or the formation of DPCs in oxygenated 9L cells. These results support the use of this DNA damage assay for the detection and quantification of hypoxic cells in solid tumors. 27 refs., 5 tabs

  1. Energy spectra of secondary neutrons produced by high-energy bremsstrahlung in carbon, nitrogen, oxygen and tissue

    International Nuclear Information System (INIS)

    The energy spectra of secondary neutrons produced when bremsstrahlung of end-point energy in the range 10-30 MeV is incident on oxygen, carbon and nitrogen have been calculated. Photonuclear reactions of the type (γ,n) and (γ,pn) have been included. The respective contributions of various nuclear reactions have been adjusted using the published values of experimentally determined cross-sections, or branching ratios, where these are available. Where no such information exists in the literature, the values have been empirically estimated. Agreement has been obtained between the calculated photoneutron spectra from C, N and O at various energies and the available experimentally-measured spectra. The photoneutron spectra from C,N and O have been combined in the right proportion (C5H40O18N) to compute the spectra of secondary neutrons from tissue irradiated with bremsstrahlung of end-point energy from 10-30 MeV. Mean neutron energies and kerma factors for these spectra have been calculated. (author)

  2. Treadmill exercise induces neutrophil recruitment into muscle tissue in a reactive oxygen species-dependent manner. An intravital microscopy study.

    Directory of Open Access Journals (Sweden)

    Albená Nunes-Silva

    Full Text Available Intense exercise is a physiological stress capable of inducing the interaction of neutrophils with muscle endothelial cells and their transmigration into tissue. Mechanisms driving this physiological inflammatory response are not known. Here, we investigate whether production of reactive oxygen species is relevant for neutrophil interaction with endothelial cells and recruitment into the quadriceps muscle in mice subjected to the treadmill fatiguing exercise protocol. Mice exercised until fatigue by running for 56.3±6.8 min on an electric treadmill. Skeletal muscle was evaluated by intravital microscopy at different time points after exercise, and then removed to assess local oxidative stress and histopathological analysis. We observed an increase in plasma lactate and creatine kinase (CK concentrations after exercise. The numbers of monocytes, neutrophils, and lymphocytes in blood increased 12 and 24 hours after the exercise. Numbers of rolling and adherent leukocytes increased 3, 6, 12, and 24 hours post-exercise, as assessed by intravital microscopy. Using LysM-eGFP mice and confocal intravital microscopy technology, we show that the number of transmigrating neutrophils increased 12 hours post-exercise. Mutant gp91phox-/- (non-functional NADPH oxidase mice and mice treated with apocynin showed diminished neutrophil recruitment. SOD treatment promoted further adhesion and transmigration of leukocytes 12 hours after the exercise. These findings confirm our hypothesis that treadmill exercise increases the recruitment of leukocytes to the postcapillary venules, and NADPH oxidase-induced ROS plays an important role in this process.

  3. Effects of ketamine on the circulatory functions and body tissue oxygenation in dogs under normal and hypovolemic conditions.

    Science.gov (United States)

    Chen, T S; Yeh, F C; Chou, Y P; Chen, H I

    1984-04-01

    Anesthetic induction with ketamine may cause cardiovascular (CV) stimulation and depression. The study was conducted in dogs to evaluate the dependence of ketamine-induced CV effects upon the dosage, mode of administration and experimental hypovolemic conditions. Slow ketamine infusion (n = 12) at 3 dose levels (5 mg/kg/min for 1, 2 and 4 min to a total dose of 5, 10 and 20 mg/kg) consistently increased the arterial pressure (AP) and heart rate (HR). Rapid bolus injections at 5, 10 and 20 mg/kg (n = 16) produced biphasic changes--decreases followed by increases in AP and HR. Profound depressor and bradycardic responses were readily observed with large dose, rapid bolus injection and during hemorrhagic hypotension. The striking CV depression in some cases became irreversible and led to death. Further study in 8 open-chest dogs revealed that ketamine infusion (a total dose of 10 mg/kg) caused slight increases in cardiac output (CO) and tissue oxygen uptake (VO2). However, the marked depressor response to bolus injection was associated with decreases in CO, total peripheral resistance, stroke volume and VO2. These inhibitory effects were prolonged after hemorrhagic hypotension. In a few cases, CO and VO2 became severely and progressively depressed and death ensued shortly following the injection. PMID:6571587

  4. Therapeutic interventions in cerebral palsy.

    Science.gov (United States)

    Patel, Dilip R

    2005-11-01

    Various therapeutic interventions have been used in the management of children with cerebral palsy. Traditional physiotherapy and occupational therapy are widely used interventions and have been shown to be of benefit in the treatment of cerebral palsy. Evidence in support of the effectiveness of the neurodevelopmental treatment is equivocal at best. There is evidence to support the use and effectiveness of neuromuscular electrical stimulation in children with cerebral palsy. The effectiveness of many other interventions used in the treatment of cerebral palsy has not been clearly established based on well-controlled trials. These include: sensory integration, body-weight support treadmill training, conductive education, constraint-induced therapy, hyperbaric oxygen therapy, and the Vojta method. This article provides an overview of salient aspects of popular interventions used in the management of children with cerebral palsy. PMID:16391455

  5. HMG-CoA Reductase Inhibition Promotes Neurological Recovery, Peri-Lesional Tissue Remodeling, and Contralesional Pyramidal Tract Plasticity after Focal Cerebral Ischemia.

    Science.gov (United States)

    Kilic, Ertugrul; Reitmeir, Raluca; Kilic, Ülkan; Caglayan, Ahmet Burak; Beker, Mustafa Caglar; Kelestemur, Taha; Ethemoglu, Muhsine Sinem; Ozturk, Gurkan; Hermann, Dirk M

    2014-01-01

    3-Hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors are widely used for secondary stroke prevention. Besides their lipid-lowering activity, pleiotropic effects on neuronal survival, angiogenesis, and neurogenesis have been described. In view of these observations, we were interested whether HMG-CoA reductase inhibition in the post-acute stroke phase promotes neurological recovery, peri-lesional, and contralesional neuronal plasticity. We examined effects of the HMG-CoA reductase inhibitor rosuvastatin (0.2 or 2.0 mg/kg/day i.c.v.), administered starting 3 days after 30 min of middle cerebral artery occlusion for 30 days. Here, we show that rosuvastatin treatment significantly increased the grip strength and motor coordination of animals, promoted exploration behavior, and reduced anxiety. It was associated with structural remodeling of peri-lesional brain tissue, reflected by increased neuronal survival, enhanced capillary density, and reduced striatal and corpus callosum atrophy. Increased sprouting of contralesional pyramidal tract fibers crossing the midline in order to innervate the ipsilesional red nucleus was noticed in rosuvastatin compared with vehicle-treated mice, as shown by anterograde tract tracing experiments. Western blot analysis revealed that the abundance of HMG-CoA reductase was increased in the contralesional hemisphere at 14 and 28 days post-ischemia. Our data support the idea that HMG-CoA reductase inhibition promotes brain remodeling and plasticity far beyond the acute stroke phase, resulting in neurological recovery. PMID:25565957

  6. Drug Therapy and Combined with Hyperbaric Oxygen in the Treatment of Acute Cerebral Infarction Clinical Analysis%单纯药物治疗与联合高压氧治疗急性脑梗死临床分析

    Institute of Scientific and Technical Information of China (English)

    杨淑琴; 张泽萍

    2013-01-01

      Objective:To study the effects of hyperbaric oxygen in the treatment of cerebral infarction and clinical analysis. Method:A retrospective study of our hospital from 2010 July to 2012 March,80 patients with acute cerebral infarction. Patients were randomly divided into 2 groups, 40 cases in the control group only received drug therapy,The treatment group of 40 cases in addition to drug treatment,also given the hyperbaric oxygen therapy. According to the“European Stroke Scale”(ESS)in the treatment group and the control group before and after treatment,and observe the clinical curative effect,score. Result:Drug and hyperbaric oxygen in the treatment of acute cerebral infarction clinical curative effect is better than simple drug use. Conclusion:Early hyperbaric oxygen treatment,In many ways to better improve brain ischemia,hypoxia,so as to achieve the purpose of treatment.%  目的:探讨高压氧治疗脑梗死的效果并进行临床分析。方法:回顾性研究笔者所在医院2010年4月-2012年11月急性脑梗死住院病例80例。随机分为两组,对照组40例,仅单纯药物治疗。治疗组40例,单纯药物治疗+高压氧治疗。根据“欧洲卒中量表”(ESS)对治疗组和对照组于治疗前、后,进行评分并观察疗效。结果:药物联合高压氧治疗急性脑梗死临床疗效优于单纯使用药物。结论:及早进行高压氧的治疗,并配合康复锻炼对减少梗死后的残疾、提高生活质量有极大的帮助。

  7. Tuberculoma cerebral Cerebral tuberculoma

    Directory of Open Access Journals (Sweden)

    ELIZABETH CLARA BARROSO

    2002-01-01

    Full Text Available Relata-se o caso de paciente com crises convulsivas de início recente. A tomografia computadorizada cerebral evidenciou imagem sugestiva de lesão expansiva metastática frontoparietal direita. A investigação de tumor primário ou outra doença foi negativa e o exame histopatológico do tecido cerebral diagnosticou tuberculoma. As convulsões foram controladas com a associação de hidantoína 300mg/dia ao esquema específico, utilizado por 18 meses. A tuberculose do sistema nervoso central representa 5-15% das formas extrapulmonares e é reconhecida como de alta letalidade. Apresentação tumoral como a relatada é rara, particularmente em imunocompetentes. Quando tratada, pode ter bom prognóstico e deve entrar sempre no diagnóstico diferencial de massas cerebrais.It is reported a case of a previously healthy man with seizures of sudden onset. A contrast head computerized tomogram (CT showed a right frontoparietal expanding lesion suggesting to be metastatic. No prior disease was found on investigation. The histologic exam of the brain revealed tuberculoma. The seizures were controlled with Hidantoin 300 mg/day and antituberculosis chemotherapy for 18 months. Central nervous system tuberculosis (5-15% of the extrapulmonary forms is highly lethal. The case reported herein is specially rare in immunocompetent patients. It may have good prognosis and should be considered in the differential diagnosis of brain tumours.

  8. Brain tissue aspiration neural tube defect Aspiração de tecido cerebral em casos de defeitos de fechamento do tubo neural

    Directory of Open Access Journals (Sweden)

    Luiz Cesar Peres

    2005-09-01

    Full Text Available The study aimed to find out how frequent is brain tissue aspiration and if brain tissue heterotopia could be found in the lung of human neural tube defect cases. Histological sections of each lobe of both lungs of 22 fetuses and newborn with neural tube defect were immunostained for glial fibrillary acidic protein (GFAP. There were 15 (68.2% females and 7 (31.8% males. Age ranged from 18 to 40 weeks of gestation (mean= 31.8. Ten (45.5% were stillborn, the same newborn, and 2 (9.1% were abortuses. Diagnosis were: craniorrhachischisis (9 cases, 40.9%, anencephaly (8 cases, 36,4%, ruptured occipital encephalocele and rachischisis (2 cases, 9.1% each, and early amniotic band disruption sequence (1 case, 4.5%. Only one case (4.5% exhibited GFAP positive cells inside bronchioles and alveoli admixed to epithelial amniotic squames. No heterotopic tissue was observed in the lung interstitium. We concluded that aspiration of brain tissue from the amniotic fluid in neural tube defect cases may happen but it is infrequent and heterotopia was not observed.O objetivo do estudo foi identificar qual a freqüência de aspiração de tecido cerebral e a existência de heterotopia nos pulmões de casos humanos de defeito de fechamento do tubo neural através da reação imuno-histoquímica para proteína fibrilar glial ácida (GFAP em cortes histológicos de todos os lobos de ambos os pulmões de 22 casos de fetos e neonatos com defeito de fechamento do tubo neural. Havia 15 casos femininos (68,2% e 7 masculinos (31,8%, com idade gestacional variando de 18 a 40 semanas (média= 31,8, sendo natimortos e neomortos 10 (45,5% cada e 2 (9,1% abortos. Os diagnósticos foram: Craniorraquisquise (9 casos, 40,9%, anencefalia (8 casos, 36,4%, encefalocele occipital rota e raquisquise (2 casos, 9,1% e 1 (4,5%caso de seqüência de disruptura amniótica precoce. Somente 1 caso (4,5% apresentou células positivas dentro de bronquíolos e alvéolos em meio a células epiteliais

  9. Integrated Measurements of Electrical Activity, Oxygen Tension, Blood Flow, and Ca2+ -Signaling in Rodents In Vivo

    DEFF Research Database (Denmark)

    Mathiesen, Claus; Thomsen, Kirsten; Lauritzen, Martin

    2014-01-01

    in rodent preparation. We also describe methods for recording of cerebral blood flow (CBF), tissue partial pressure of oxygen (tpO2), and cytosolic calcium transients. We finally give examples where electrophysiology, blood flow, metabolism, and calcium transients have been studied together....

  10. Role of Aquaporin-4 in Cerebral Edema and Stroke

    OpenAIRE

    Zador, Zsolt; Stiver, Shirley; Wang, Vincent; Manley, Geoffrey T.

    2009-01-01

    Cerebral edema plays a central role in the pathophysiology of many diseases of the central nervous system (CNS) including ischemia, trauma, tumors, inflammation, and metabolic disturbances. The formation of cerebral edema results in an increase in tissue water content and brain swelling which, if unchecked, can lead to elevated intracranial pressure (ICP), reduced cerebral blood flow, and ultimately cerebral herniation and death. Despite the clinical significance of cerebral edema, the mechan...

  11. Cerebral Palsy

    Science.gov (United States)

    ... 1 • 2 • 3 For Teens For Kids For Parents MORE ON THIS TOPIC Cerebral Palsy: Keith's Story Physical Therapy I Have Cerebral Palsy. Can I Babysit? Body Image and Self-Esteem Contact Us Print Resources Send to a friend ...

  12. The role of tissue oxygen tension in the control of local blood flow in the microcirculation of skeletal muscles

    DEFF Research Database (Denmark)

    Ngo, Thuc Anh

    2010-01-01

    . In a separate study we examined if low or high oxygen caused any change in the intracellular Ca2+ concentration of isolated mouse cremaster arterioles using fluorescent microscopy. Cremaster arterioles were isolated by gentle microdissection, loaded with Fura-PE3 (calcium fluorescent dye) and placed...... high oxygen perfusate. Possible explanations for these findings could be: a) that the oxygen sensing mechanism was damaged during the dissection procedure, b) changes in oxygen tension does not cause changes in the intracellular Ca2+ concentration, but rather changes the Ca2+ sensitivity of contractive...

  13. MRI of sickle cell cerebral infarction

    International Nuclear Information System (INIS)

    Eleven patients with sickle cell disease and neurological symptoms underwent MRI examination. Cerebral infarcts of two types were found, those in the vascular distribution of the middle cerebral artery and those in the deep white matter. In the patient whose hydration and whose oxygenation of erythrocytes has been treated, MRI offers diagnostic advantages over arteriography and CT. (orig.)

  14. Tracking of In-111-labeled human umbilical tissue-derived cells (hUTC) in a rat model of cerebral ischemia using SPECT imaging

    International Nuclear Information System (INIS)

    In order to increase understanding of how infused cells work, it becomes important to track their initial movement, localization, and engraftment efficiency following transplantation. However, the available in vivo cell tracking techniques are suboptimal. The study objective was to determine the biodistribution of intravenously administered Indium-111 (In-111) oxine labeled human umbilical tissue-derived cells (hUTC) in a rat model of transient middle cerebral occlusion (tMCAo) using single photon emission computed tomography (SPECT). Rats received 3 million In-111 labeled hUTC (i.v.) 48 hrs after tMCAo. Following the administration of either hUTC or equivalent dose of In-111-oxine (18.5 MBq), animals underwent SPECT imaging on days 0, 1, and 3. Radioactivity in various organs as well as in the stroke area and contralateral hemisphere was determined, decay corrected and normalized to the total (whole body including head) radioactivity on day 0. Immunohistochemical analysis was also performed to confirm the beneficial effects of hUTC on vascular and synaptic density, and apoptosis. Most of the radioactivity (43.36±23.07% on day 0) trafficked to the lungs immediately following IV administration of In-111 labeled hUTC (day 0) and decreased drastically to 8.81±7.75 and 4.01±4.52% on days 1 and 3 post-injection, respectively. In contrast, radioactivity measured in the lung of animals that received In-111-oxine alone remained relatively unchanged from day 0 to day 1 (18.38±5.45% at day 0 to 12.59±5.94%) and decreased to 8.34±4.25% on day 3. Significantly higher radioactivity was observed in stroke areas of animals that received In-111 labeled hUTC indicating the presence of cells at the site of injury representing approximately 1% of total administered dose. In addition, there was significant increase in vascular and synaptophysin immunoreactivity in stroke areas of rats that received In-111 labeled hUTC. The present studies showed the tracking of In-111 labeled h

  15. Acupressure at the Meridian Acupoint Xiyangguan (GB33 Influences Near-Infrared Spectroscopic Parameters (Regional Oxygen Saturation in Deeper Tissue of the Knee in Healthy Volunteers

    Directory of Open Access Journals (Sweden)

    Gerhard Litscher

    2013-01-01

    Full Text Available Up to now, it is still unknown whether microcirculation of deeper peripheral tissue (knee can be modulated by acupuncture or acupressure on a meridian acupoint. The goal of this pilot study was to investigate possible effects of acupressure at the Xiyangguan acupoint (GB33 on the regional oxygen saturation of the deeper knee tissues by near-infrared spectroscopy (NIRS. Twelve healthy volunteers with a mean age of 23.8±1.6 years were investigated. Acupressure stimulation was performed for 5 minutes at the Xiyangguan acupoint. The results of the controlled study showed a significant increase of the values of regional oxygen saturation on the stimulated side of the knee (P=0.033, whereas the opposite side on the same knee showed insignificant changes. These results may serve as a valuable basis for monitoring a possible therapeutic effect (e.g., after Khalifa therapy in patients with knee problems.

  16. The problems of tissue oxygenation in diabetes mellitus. III. The "three-in-one concept" for the development of diabetic microangiopathy and a rational approach to its prophylaxis.

    Science.gov (United States)

    Ditzel, J

    1975-01-01

    Evidence for a causative relationship between prolonged tissue hypoxia and diabetic retinopathy and glomerulosclerosis are presented. Based on the assumption that one of the most fundamental requirements for optimal cellular metabolism is a constant cellular oxygen tension, the "three-in-one concept" for the development of diabetic microangiopathy is formulated. The term "three-in-one" is employed because this concept partly or completely includes "the glycoprotein-", "the hypoxia-", and "the growth hormone hypothesis". Diabetics show evidence of variability in the tissue oxygen availability/demand ratio which is compensated by three self-regulating factors: 1) an increase in local flow, 2) an increase in red cell 2,3-DPG leading to a shift to the right of the oxyhaemoglobin dissociation curve, and 3) an increase in the oxygen-binding capacity or the haemoglobin concentration. The level of plasma inorganic phosphate (Pi) is of importance in maintaining high 2,3-DPG levels. However, since Pi fluctuates depending upon changes in the control of diabetes, the regulatory mechanism of the 2,3-DPG modulated unloading of oxygen from the erythrocytes often becomes insufficient, and therefore in poorly regulated diabetics with less than optimal 2,3-DPG levels, the main load of compensation against tissue hypoxia is placed on an adjustment in the microcirculation of the organ involved. However, in order for the microvascular dilatation to occur, the cells must experience a hypoxic stimulus. The summation of the infinite number of discrete and occasionally pronounced hypoxic injuries to the tissue cells in association with the adverse effect of local vasodilatation with increased plasma permeation through the vessel walls might over the years lead to diabetic microangiopathy. Based on this theory the high level of Pi in diabetes becomes of particular significance. Our experience with a high phosphate diabetes diet in the treatment of diabetics is presented. This dietary

  17. Glycopyrrolate abolishes the exercise-induced increase in cerebral perfusion in humans

    DEFF Research Database (Denmark)

    Seifert, Thomas; Fisher, James P; Young, Colin N;

    2010-01-01

    Brain blood vessels contain muscarinic receptors that are important for cerebral blood flow (CBF) regulation, but whether a cholinergic receptor mechanism is involved in the exercise-induced increase in cerebral perfusion or affects cerebral metabolism remains unknown. We evaluated CBF and cerebr...... abolished by glycopyrrolate (P <0.05). Thus, during both cycling and static handgrip, a cholinergic receptor mechanism is important for the exercise-induced increase in cerebral perfusion without affecting the cerebral metabolic rate for oxygen....

  18. Effects of exposing rats to 100% oxygen at 450 and 600 mm Hg on in vitro liver and adipose tissue lipid synthesis.

    Science.gov (United States)

    Feller, D. D.; Neville, E. D.; Talarico, K. S.

    1972-01-01

    Male rats (260-285 gm) were exposed to 100% oxygen at 450 or 600 mm Hg for 1 to 4 days. Rats maintained at 450 mm Hg ate 92% the amount of food eaten by ad libitum controls maintained at sea level conditions. At 600 mm Hg, the food intake was 77% of the ad libitum controls. No difference was found in the plasma level of glucose, free fatty acids, and corticosterone between oxygen exposed rats and their respective pair-fed controls. The in vitro conversion of acetate into fatty acids by adipose tissue from rats exposed at 450 mm Hg for 2, 3, or 4 days was significantly increased above pair-fed controls and ad libitum controls. Increasing the oxygen pressure to 600 mm Hg abolished this increase, and in fact, reversed the increased synthesis to a significant decrease for the 4-day exposure.

  19. Simultaneous multi-depth assessment of tissue oxygen saturation in thenar and forearm using near-infrared spectroscopy during a simple cardiovascular challenge

    OpenAIRE

    Bezemer, R.; Karemaker, J. M.; Klijn, E; D. Martin; Mitchell, K; Grocott, M.; Heger, M; Ince, C.

    2009-01-01

    INTRODUCTION: Hypovolemia and hypovolemic shock are life-threatening conditions that occur in numerous clinical scenarios. Near-infrared spectroscopy (NIRS) has been widely explored, successfully and unsuccessfully, in an attempt to use it as an early detector of hypovolemia by measuring tissue oxygen saturation (StO2). In order to investigate the measurement site dependence and probe dependence of NIRS in response to hemodynamic changes, such as hypovolemia, we applied a simple cardiovascula...

  20. Cerebral palsy.

    Science.gov (United States)

    Graham, H Kerr; Rosenbaum, Peter; Paneth, Nigel; Dan, Bernard; Lin, Jean-Pierre; Damiano, Diane L; Becher, Jules G; Gaebler-Spira, Deborah; Colver, Allan; Reddihough, Dinah S; Crompton, Kylie E; Lieber, Richard L

    2016-01-01

    Cerebral palsy is the most common cause of childhood-onset, lifelong physical disability in most countries, affecting about 1 in 500 neonates with an estimated prevalence of 17 million people worldwide. Cerebral palsy is not a disease entity in the traditional sense but a clinical description of children who share features of a non-progressive brain injury or lesion acquired during the antenatal, perinatal or early postnatal period. The clinical manifestations of cerebral palsy vary greatly in the type of movement disorder, the degree of functional ability and limitation and the affected parts of the body. There is currently no cure, but progress is being made in both the prevention and the amelioration of the brain injury. For example, administration of magnesium sulfate during premature labour and cooling of high-risk infants can reduce the rate and severity of cerebral palsy. Although the disorder affects individuals throughout their lifetime, most cerebral palsy research efforts and management strategies currently focus on the needs of children. Clinical management of children with cerebral palsy is directed towards maximizing function and participation in activities and minimizing the effects of the factors that can make the condition worse, such as epilepsy, feeding challenges, hip dislocation and scoliosis. These management strategies include enhancing neurological function during early development; managing medical co-morbidities, weakness and hypertonia; using rehabilitation technologies to enhance motor function; and preventing secondary musculoskeletal problems. Meeting the needs of people with cerebral palsy in resource-poor settings is particularly challenging. PMID:27188686

  1. Enhanced cerebrovascular expression of matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 via the MEK/ERK pathway during cerebral ischemia in the rat

    DEFF Research Database (Denmark)

    Maddahi, Aida; Chen, Qingwen; Edvinsson, Lars

    2009-01-01

    BACKGROUND: Cerebral ischemia is usually characterized by a reduction in local blood flow and metabolism and by disruption of the blood-brain barrier in the infarct region. The formation of oedema and opening of the blood-brain barrier in stroke is associated with enhanced expression of metallopr......BACKGROUND: Cerebral ischemia is usually characterized by a reduction in local blood flow and metabolism and by disruption of the blood-brain barrier in the infarct region. The formation of oedema and opening of the blood-brain barrier in stroke is associated with enhanced expression...

  2. Cerebral and muscle deoxygenation, hypoxic ventilatory chemosensitivity and cerebrovascular responsiveness during incremental exercise.

    Science.gov (United States)

    Peltonen, Juha E; Paterson, Donald H; Shoemaker, J Kevin; Delorey, Darren S; Dumanoir, Gregory R; Petrella, Robert J; Kowalchuk, John M

    2009-10-31

    To examine if cerebral (frontal cortex) and skeletal muscle (m. vastus lateralis) deoxygenation and cerebral blood flow velocity (V(mean)) in the middle cerebral artery differentiated between normoxic and hypoxic (end-tidal P(O)(2) 71 mmHg) conditions, and if they were associated with hypoxic ventilatory chemosensitivity and cerebrovascular responsiveness, 8 men performed incremental cycling trials (30W/min ramp) under normoxic (T1-N) and hypoxic (T1-H) conditions until volitional fatigue, or until arterial O2 saturation decreased below 80%. The tests were repeated (T2-N; T2-H) on another day with supplemental O2 (Sup-O2) at the end of exercise. The V(mean) response was similar in normoxia and hypoxia. In hypoxia compared to normoxia, cerebral deoxygenation ( upward arrow deoxyhemoglobin concentration (Delta[HHb]) and downward arrow tissue oxygenation index (TOI)) was greater at a given work rate. A strong hypoxic ventilatory chemosensitivity was associated with a rapid reduction of cerebral TOI (r=0.94, PMuscle deoxygenation was similar in normoxia and hypoxia suggesting greater muscle blood flow in hypoxia compared to normoxia and thus the existence of control features that match muscle perfusion and O2 delivery tightly with O2 demand during exercise. Sup-O2 reduced both cerebral and muscle deoxygenation, at least transiently. PMID:19729079

  3. MRI of cerebral blood flow under hyperbaric conditions in rats.

    Science.gov (United States)

    Cardenas, Damon P; Muir, Eric R; Duong, Timothy Q

    2016-07-01

    Hyperbaric oxygen (HBO) therapy has a number of clinical applications. However, the effects of acute HBO on basal cerebral blood flow (CBF) and neurovascular coupling are not well understood. This study explored the use of arterial spin labeling MRI to evaluate changes in baseline and forepaw stimulus-evoked CBF responses in rats (n = 8) during normobaric air (NB), normobaric oxygen (NBO) (100% O2 ), 3 atm absolute (ATA) hyperbaric air (HB) and 3 ATA HBO conditions. T1 was also measured, and the effects of changes in T1 caused by increasing oxygen on the CBF calculation were investigated. The major findings were as follows: (i) increased inhaled oxygen concentrations led to a reduced respiration rate; (ii) increased dissolved paramagnetic oxygen had significant effects on blood and tissue T1 , which affected the CBF calculation using the arterial spin labeling method; (iii) the differences in blood T1 had a larger effect than the differences in tissue T1 on CBF calculation; (iv) if oxygen-induced changes in blood and tissue T1 were not taken into account, CBF was underestimated by 33% at 3 ATA HBO, 10% at NBO and HBO, HB and NBO were similar (p > 0.05) and all were higher than CBF under NB by ~40% (p HBO, similar to NB, supporting the notion that activation-induced CBF regulation in the brain does not operate through an oxygen-sensing mechanism. CBF MRI provides valuable insights into the effects of oxygen on basal CBF and neurovascular coupling under hyperbaric conditions. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27192391

  4. Protective Effect of Extract of Folium Ginkgo on Repeated Cerebral Ischemia-Reperfusion Injury

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective: To study the protective effect of extract of Folium Ginkgo (FGE) on repeated cerebral ischemia-reperfusion injury. Methods: The model in waking mice induced by repeated cerebral ischemia-reperfusion were used in the experiment to observe the effect of FGE on behavior, oxygen free radical metabolism and prostaglandin E2 (PGE2) content by step-through experiment, diving stand and colorimetric method. Results: FGE could obviously improve the learning ability and memory of model animals, and could lower obviously the content of malonyldialdehyde, nitric oxide and PGE2, restore the lowered activity of superoxide dismutase and catalase in cerebral tissue. Conclusion: FGE has highly protective effect against repeated ischemia-reperfusion injury, the mechanism might be related with its action on anti-lipid oxidatin, improve the activity of antioxidase and inhibit the producing of PGE2.

  5. Changes in cerebral oxidative metabolism in patients with acute liver failure

    DEFF Research Database (Denmark)

    Bjerring, P N; Larsen, F S

    2013-01-01

    Acute liver failure patients with a persistence of hyperammonemia are at an increased risk of intracranial hypertension due to development of brain oedema. In vitro studies of brain tissue and cell cultures that indicates that exposure to ammonium inhibits enzymatic activity in the tricarboxylic...... acid cycle, induces substrate depletion through marked glutamate utilization for glutamine synthesis and leads to mitochondrial dysfunction. In patients with acute liver failure cerebral microdialysis studies show a linear correlation between the lactate to pyruvate ratio and the glutamine...... concentration, as well as to some of the adenosine triphosphate degradation products. However, clinical observations of cerebral exchange rates of oxygen, glucose, lactate and amino acids challenge the interpretation of these findings. In this review the conflicting data of cerebral metabolism during acute...

  6. Cerebral hypoxia

    Science.gov (United States)

    ... the veins ( deep vein thrombosis ) Lung infections (pneumonia) Malnutrition When to Contact a Medical Professional Cerebral hypoxia ... References Bernat JL. Coma, vegetative state, and brain death. In: Goldman L, Schafer AI, eds. Goldman's Cecil ...

  7. Tissue microcirculation measured by vascular occlusion test during anesthesia induction.

    Science.gov (United States)

    Kim, Tae Kyong; Cho, Youn Joung; Min, Jeong Jin; Murkin, John M; Bahk, Jae-Hyon; Hong, Deok Man; Jeon, Yunseok

    2016-02-01

    Tissue microcirculation measured by vascular occlusion test is impaired during septic shock. However, it has not been investigated extensively during anesthesia induction. The aim of the study is to evaluate tissue microcirculation during anesthesia induction. We hypothesized that during anesthesia induction, tissue microcirculation measured by vascular occlusion test might be enhanced with peripheral vasodilation during anesthesia induction. We conducted a prospective observational study of 50 adult patients undergoing cardiac surgery. During anesthesia induction, we measured and analyzed tissue oxygen saturation, vascular occlusion test, cerebral oximetry, forearm-minus-fingertip skin temperature gradients and hemodynamic data in order to evaluate microcirculation as related to alterations in peripheral vasodilation as reflected by increased Tforearm-finger thermal gradients. During anesthesia induction, recovery slope during vascular occlusion test and cerebral oxygen saturation increased from 4.0 (1.5) to 4.7 (1.3) % s(-1) (p = 0.02) and 64.0 (10.2) to 74.2 (9.2) % (p Forearm-minus-fingertip skin temperature gradients decreased from 1.9 (2.9) to -1.4 (2.2) °C (p blood pressure and forearm-minus-fingertip skin temperature gradients decrease while cerebral oximetry and vascular occlusion test recovery slope increase. These findings suggest that anesthesia induction increases tissue microcirculation with peripheral vasodilation. PMID:25750016

  8. Effects of deliberate hypotension with remifentanil on hemodynamics and cerebral oxygen supply and consumption in craniocerebral operations%瑞芬太尼用于颅脑手术控制性降压的研究

    Institute of Scientific and Technical Information of China (English)

    骆智宇; 莫惠飞; 李斌

    2011-01-01

    Objectve To observe the effects of deliberate nypotension witn remifentanil on hemodynamics and cerebral oxygen supply and consumption in craniocerebral operations. Methods Thirty ASA Ⅰ or Ⅱ patients undcrgoing elective craniocerebral operations were equally randomized into two groups to induce deliberate hypotension with remifentanil (R group) and sodium nitroprusside (N group). HR, MAP, CVP, PErCO2 and SpO2 were monotored during operations.Blood samples were taken from radial artery and internal jugular bulb to determine cerebral arteriovenous oxygen differences (Da-jvO2), cerebral oxygen extraction (CERO2), and rate-pressure product (RPP). Results HR was lower in R group cmpared with N group (P<0. 05). Da-jrO2 and CERO2 decreased during deliberate hypotension in two groups (P<0. 05), however there was no significant difference between the two groups. Conclusion Deliberate hypotension with remifentanil improves cerebral blood flow-metabolism coupling without increasing HR.%目的 观察瑞芬太尼用于颅脑手术控制性降压对血流动力学和脑氧代谢的影响.方法 择期行颅脑手术患者30例,ASA Ⅰ或Ⅱ级,随机均分为瑞芬太尼组(R组)和硝普钠组(N组).术中监测和记录手术前、降压前、达到目标血压0 rain(T0)、5 min(T1)、10 min(T2)、20 min(T3)、30min(T4)及停止降压5 min(T5)、10 min(T6)、30 min(T7)时的HR、MAP、CVP、P盯C02和spO2,并抽取桡动脉、右颈内静脉球部血标本测血气,计算麻醉后、手术前、降压前、达到目标血压10 min的颈内静脉球部血氧含量差(Da-jvO2)、脑氧代谢率(CERO2)、RPP.结果 R组各时点HR慢于N组(P<0.05).R组和N组的Da-jvO2、CERO2在降压时均下降(P<0.05),但两组差异无统计学意义.结论 瑞芬太尼用于颅脑手术控制性降压在改善脑氧代谢的同时不增快HR.

  9. Modification of the radiation response of pig skin by manipulation of tissue oxygen tension using anesthetics and administration of BW12C

    International Nuclear Information System (INIS)

    The importance of tissue oxygen tension on radiosensitivity was studied by examining modifications in the incidence of moist desquamation in pig skin after irradiation with strontium-90 plaques. The effects were analyzed using quantal dose-response data and comparisons were made using ED50 values for moist desquamation. Under standard anesthetic conditions of 2% halothane, approximately 70% oxygen, and approximately 30% nitrous oxide, the ED50 value (+/- SE) for moist desquamation was 27.32 +/- 0.52 Gy with no significant variation in radiosensitivity between dorsal, lateral, and ventral skin sites on the flank. Irradiation with 2% halothane and air increased the ED50 to 31.25 +/- 0.94 Gy, primarily due to an increased radioresistance of the dorsal sites. When combined with BW12C, a drug which binds oxygen selectively to hemoglobin and hence reduced the oxygen availability to tissues, a further increase in the ED50 values was observed. This was approximately 39 Gy with BW12C concentrations of 30 mg/kg and 50 mg/kg b.w. of BW12C, indicating a dose modification factor (DMF) of approximately 1.26. However, when animals were breathing the standard gas mixture, this DMF was reduced to 1.15 for 30 mg/kg of BW12C, indicating that a higher level of oxygen partly counteracted the effects of the drug in these studies with BW12C. The greatest variability in radiosensitivity was seen in the dorsal fields. This suggested complex physiological adaptation, a phenomenon that might also explain the absence of any modification of the radiation response when 100 mg/kg of BW12C was used

  10. Non-invasive optical measurement of cerebral metabolism and hemodynamics in infants.

    Science.gov (United States)

    Lin, Pei-Yi; Roche-Labarbe, Nadege; Dehaes, Mathieu; Carp, Stefan; Fenoglio, Angela; Barbieri, Beniamino; Hagan, Katherine; Grant, P Ellen; Franceschini, Maria Angela

    2013-01-01

    Perinatal brain injury remains a significant cause of infant mortality and morbidity, but there is not yet an effective bedside tool that can accurately screen for brain injury, monitor injury evolution, or assess response to therapy. The energy used by neurons is derived largely from tissue oxidative metabolism, and neural hyperactivity and cell death are reflected by corresponding changes in cerebral oxygen metabolism (CMRO₂). Thus, measures of CMRO₂ are reflective of neuronal viability and provide critical diagnostic information, making CMRO₂ an ideal target for bedside measurement of brain health. Brain-imaging techniques such as positron emission tomography (PET) and single-photon emission computed tomography (SPECT) yield measures of cerebral glucose and oxygen metabolism, but these techniques require the administration of radionucleotides, so they are used in only the most acute cases. Continuous-wave near-infrared spectroscopy (CWNIRS) provides non-invasive and non-ionizing radiation measures of hemoglobin oxygen saturation (SO₂) as a surrogate for cerebral oxygen consumption. However, SO₂ is less than ideal as a surrogate for cerebral oxygen metabolism as it is influenced by both oxygen delivery and consumption. Furthermore, measurements of SO₂ are not sensitive enough to detect brain injury hours after the insult, because oxygen consumption and delivery reach equilibrium after acute transients. We investigated the possibility of using more sophisticated NIRS optical methods to quantify cerebral oxygen metabolism at the bedside in healthy and brain-injured newborns. More specifically, we combined the frequency-domain NIRS (FDNIRS) measure of SO2 with the diffuse correlation spectroscopy (DCS) measure of blood flow index (CBFi) to yield an index of CMRO₂ (CMRO₂i). With the combined FDNIRS/DCS system we are able to quantify cerebral metabolism and hemodynamics. This represents an improvement over CWNIRS for detecting brain health, brain

  11. [Should cerebral autoregulation be reassessed?

    DEFF Research Database (Denmark)

    Secher, Niels H.

    2009-01-01

    Maintained cardiac output (CO) and cerebral oxygenation (ScO2) are of importance for a reduction in perioperative complications. Normovolaemia is defined as a central blood volume that does not limit CO for the supine patient and is maintained by individualized goal directed fluid therapy. Thereby...

  12. A Prospective Randomized Study of Brain Tissue Oxygen Pressure-Guided Management in Moderate and Severe Traumatic Brain Injury Patients

    Directory of Open Access Journals (Sweden)

    Chien-Min Lin

    2015-01-01

    Full Text Available The purpose of this study was to compare the effect of PbtO2-guided therapy with traditional intracranial pressure- (ICP- guided treatment on the management of cerebral variables, therapeutic interventions, survival rates, and neurological outcomes of moderate and severe traumatic brain injury (TBI patients. From 2009 to 2010, TBI patients with a Glasgow coma scale 20 mmHg, and 27 patients were treated with ICP-guided therapy (ICP 60 mmHg in the neurosurgical intensive care unit (NICU; demographic characteristics were similar across groups. The survival rate in the PbtO2-guided group was also significantly increased at 3 and 6 months after injury. Moreover, there was a significant correlation between the PbtO2 signal and Glasgow outcome scale-extended in patients from 1 to 6 months after injury. This finding demonstrates that therapy directed by PbtO2 monitoring is valuable for the treatment of patients with moderate and severe TBI and that increasing PaO2 to 150 mmHg may be efficacious for preventing cerebral hypoxic events after brain trauma.

  13. Hyperbaric oxygen therapy may improve symptoms in autistic children.

    Science.gov (United States)

    Rossignol, Daniel A; Rossignol, Lanier W

    2006-01-01

    Autism is a neurodevelopmental disorder that currently affects as many as 1 out of 166 children in the United States. Recent research has discovered that some autistic individuals have decreased cerebral perfusion, evidence of neuroinflammation, and increased markers of oxidative stress. Multiple independent single photon emission computed tomography (SPECT) and positron emission tomography (PET) research studies have revealed hypoperfusion to several areas of the autistic brain, most notably the temporal regions and areas specifically related to language comprehension and auditory processing. Several studies show that diminished blood flow to these areas correlates with many of the clinical features associated with autism including repetitive, self-stimulatory and stereotypical behaviors, and impairments in communication, sensory perception, and social interaction. Hyperbaric oxygen therapy (HBOT) has been used with clinical success in several cerebral hypoperfusion syndromes including cerebral palsy, fetal alcohol syndrome, closed head injury, and stroke. HBOT can compensate for decreased blood flow by increasing the oxygen content of plasma and body tissues and can even normalize oxygen levels in ischemic tissue. In addition, animal studies have shown that HBOT has potent anti-inflammatory effects and reduces oxidative stress. Furthermore, recent evidence demonstrates that HBOT mobilizes stem cells from human bone marrow, which may aid recovery in neurodegenerative diseases. Based upon these findings, it is hypothesized that HBOT will improve symptoms in autistic individuals. A retrospective case series is presented that supports this hypothesis. PMID:16554123

  14. Cerebral Palsy (For Parents)

    Science.gov (United States)

    ... Story" 5 Things to Know About Zika & Pregnancy Cerebral Palsy KidsHealth > For Parents > Cerebral Palsy Print A A ... kids who are living with the condition. About Cerebral Palsy Cerebral palsy is one of the most common ...

  15. 羟基喜树碱缓释片在大鼠脑内的释放情况研究%Drug Release of Hydroxycamptothecin Sustained-release Tablets in Cerebral Tissue of Rats

    Institute of Scientific and Technical Information of China (English)

    胡婧; 刘松青

    2012-01-01

    OBJECTIVE: To investigate the release of Hydroxycamptothecin (HCPT) sustained-release tablets in cerebral tissue of rats. METHODS: HCPT sustained-release tablets were implanted into cerebral tissue of 40 SD rats. Those rats were sacrificed on 1, 3, 7, 10, 13, 17, 21, 28 d. Residual medicine was obtained and HPLC was used to determine the amount of residual medicine and cumulative release rate was calculated. Concentrations of medicine in cerebral tissue and plasma were determined. RESULTS: The cumulative release rates of HCPT sustained-release tablets were (12.13 ± 7.58)% on the first day and(72.31 ± 15.17)% on 28th day. It indicated that drug release of HCPT sustained-release tablets lasted for more than 28 days. The concentrations of HCPT in cerebral tissue and plasma were (135.41 ±17.48) μg·mL-1 and (133.75 ± 10.81) ng·mL-1. The concentration of HCPT in cerebral tissue was higher than in plasma. CONCLUSION: HPCT sustained-release tablets can achieve ideal release effect and reduce general toxicity.%目的:考察羟基喜树碱(HCPT)缓释片植入大鼠脑内的释放情况.方法:将HCPT缓释片植入40只SD大鼠脑内,分别于第1、3、7、10、13、17、21、28天时处死大鼠,取出残留缓释片采用高效液相色谱法考察其未释放的药量并计算累积释放百分率;另取大鼠血浆和脑组织检测其中药物浓度.结果:HCPT缓释片在大鼠脑内第1、28天的累积释放百分率分别为(12.13±7.58)%、(72.31±15.17)%,表明其释放时间达28 d以上;其在大鼠脑组织和血浆中第28天的药物浓度分别为(135.41±17.48) μg·mL-1、(133.75±10.81) ng·mL-1,表明在脑组织中的药物浓度明显高于在血浆中的浓度.结论:自制的HCPT缓释片在大鼠脑内有较好的缓释效果,且可降低全身性毒副作用.

  16. EFFECT OF ELECTROACUPUNCTURE OF DUMAI-ACUPOINTS ON CEREBRAL NO AND BLOOD ENDOTHELIN CONTENTS IN RATS WITH ACUTE CEREBRAL ISCHEMIA

    Institute of Scientific and Technical Information of China (English)

    MaYang; XuNenggui; XuGuansun; ZhongPing; WangLianfa; ZhuShunli; ChenQuanzhu

    2000-01-01

    Thirty Wistar rats were randomly and evenly divided into control group, cerebral ischemia group and ischemia + electroacupuncture (EA) group. The bilateral common carotid arteries were occluded to induce acute cerebral ischemia. Nitric oxide (NO) and endothelin (ET)contents in the cerebral tissues and blood were measured under normal condition, immediately after ischemia and following EA. Results showed that after acute cerebral ischemia NO and ET contents in the cerebral tissues increased significantly (P<0.01) while serum ET increased and serum NO lowered obviously (P<0.05). Following EA of Baihui (GV 20) and Dazhui (GV 14), both NO and ET in cerebral tissues and serum turned to normal basically. It showed that EA could protect the cerebral tissues from injury induced by ischemia, NO and ET might participate in the modulation process of EA.

  17. EFFECT OF ELECTROACUPUNCTURE OF DUMAI-ACUPOINTS ON CEREBRAL NO AND BLOOD ENDOTHELIN CONTENTS IN RATS WITH ACUTE CEREBRAL ISCHEMIA

    Institute of Scientific and Technical Information of China (English)

    马杨; 许能贵; 许冠荪; 钟平; 王联发; 朱舜丽; 陈全珠

    2000-01-01

    Thirty Wistar rats were randomly and evenly divided into control group, cerebral ischemia group and ischemia + electroacupuncture (EA) group. The bilateral common carotid arteries were occluded to induce acute cerebral ischemia. Nitric oxide (NO) and endothelin (ET) contents in the cerebral tissues and blood were measured under normal condition, immediately after ischemia and following EA. Results showed that after acute cerebral ischemia NO and ET contents in the cerebral tissues increased significantly (P < 0.01) while serum ET increased and serum NO lowered obviously (P<0.05). Following EA of Baihui (GV 20) and Dazhui (GV 14), both NO and ET in cerebral tissues and serum turned to normal basically. It showed that EA could protect the cerebral tissues from injury induced bv ischemia. NO and ET might oarticioate in the modulation orocess of EA.

  18. Effect of hyperbaric oxygenation on plasma endothelin and calcitonin gene related peptide in hypertensive cerebral hemorrhage patients%高压氧对高血压脑出血患者血浆ET、CGRP的影响

    Institute of Scientific and Technical Information of China (English)

    赵波; 吕云利; 姚向荣; 廖军

    2012-01-01

    目的 探讨高压氧对高血压脑出血患者血浆内皮素(ET)、降钙素基因相关肽(CGRP)的影响.方法 选择70例高血压脑出血患者,随机分为高压氧治疗组和常规治疗组,每组35例;2组均予常规治疗,高压氧治疗组在常规治疗的基础上于入院后第5天生命体征稳定后进行高压氧治疗,每天1次,共治疗14d.采用放射免疫法在治疗不同时间点(24h、5d、14d、21d)分别测血浆ET、CGRP值.另选择35例健康体检者作为正常对照组.结果 入院时24h高压氧治疗组及常规治疗组ET值高于正常对照组,CGRP值低于正常对照组.入院后(14d、21d)高压氧治疗组ET值低于常规治疗组,CGRP值高于常规治疗组.结论 高压氧治疗可以降低血浆ET水平,提高CGRP含量,从而改善高血压脑出血患者预后,并对继发性脑损伤有一定的治疗作用.%Objective It is to investigate the effect of hyperbaric oxygenation on plasma endothelin( ET ) and calcitonin gene-related peptide( CGRP ). Methods 70 hypertensive cerebral hemorrhage patients were randomly divided into hyperbaric oxygenation therapeutic group and conventional therapy group ( 35 cases in each group ). Beside the conventional therap,patients in hyperbaric oxygenation therapeutic group also received hyperbaric oxygenation in the fifth day after being in hospital if the body signs were stable,once a day and for 14 days. The developments of ET and CGRP levels in serum from both groups were monitored ( 24 h, 5 d, 14 d, 21 d ) with radioimmunoassay ,35 healthy people ( control group ) were enrolled in this stud-y. Results The level of ET was higher and the level of CGRP was lower in treatment group and conventional therapy group than that in normal control group in 24 h after being in hospital. The level of ET was lower and the level of CGRP was higher in hyperbaric oxygenation therapy group after therapy at 14 d and 21 d than that in conventional therapy( P <0. 05 ). Conclusion Hyperbaric

  19. Comparison of cerebral oxygen saturation in premature infants by near-infrared spatially resolved spectroscopy: observations on probe-dependent bias

    DEFF Research Database (Denmark)

    Sorensen, Line C; Leung, Terence S; Greisen, Gorm

    2008-01-01

    oxygenation index (c-TOI) was measured using NIRO 300 (Hamamatsu Photonics KK). c-TOI was measured at several positions in each infant. c-TOI varied over time, increasing in the first third and decreasing in the last third of the study period (p<10(-6)). Two probes were used in the study, and a highly...

  20. Recirculation usually precedes malignant edema in middle cerebral artery infarcts

    DEFF Research Database (Denmark)

    Nielsen, T H; Ståhl, N; Schalén, W;

    2012-01-01

    In patients with large middle cerebral artery (MCA) infarcts, maximum brain swelling leading to cerebral herniation and death usually occurs 2-5 days after onset of stroke. The study aimed at exploring the pattern of compounds related to cerebral energy metabolism in infarcted brain tissue....

  1. Wearable wireless cerebral oximeter (Conference Presentation)

    Science.gov (United States)

    Zhang, Xin; Jiang, Tianzi

    2016-03-01

    Cerebral oximeters measure continuous cerebral oxygen saturation using near-infrared spectroscopy (NIRS) technology noninvasively. It has been involved into operating room setting to monitor oxygenation within patient's brain when surgeons are concerned that a patient's levels might drop. Recently, cerebral oxygen saturation has also been related with chronic cerebral vascular insufficiency (CCVI). Patients with CCVI would be benefited if there would be a wearable system to measure their cerebral oxygen saturation in need. However, there has yet to be a wearable wireless cerebral oximeter to measure the saturation in 24 hours. So we proposed to develop the wearable wireless cerebral oximeter. The mechanism of the system follows the NIRS technology. Emitted light at wavelengths of 740nm and 860nm are sent from the light source penetrating the skull and cerebrum, and the light detector(s) receives the light not absorbed during the light pathway through the skull and cerebrum. The amount of oxygen absorbed within the brain is the difference between the amount of light sent out and received by the probe, which can be used to calculate the percentage of oxygen saturation. In the system, it has one source and four detectors. The source, located in the middle of forehead, can emit two near infrared light, 740nm and 860nm. Two detectors are arranged in one side in 2 centimeters and 3 centimeters from the source. Their measurements are used to calculate the saturation in the cerebral cortex. The system has included the rechargeable lithium battery and Bluetooth smart wireless micro-computer unit.

  2. The role of UCP 1 in production of reactive oxygen species by mitochondria isolated from brown adipose tissue

    Czech Academy of Sciences Publication Activity Database

    Dlasková, Andrea; Clarke, K.J.; Porter, R. K.

    2010-01-01

    Roč. 1797, č. 8 (2010), s. 1470-1476. ISSN 0005-2728 Institutional research plan: CEZ:AV0Z50110509 Keywords : Mitochondria * Reactive oxygen species * Uncoupling protein 1 Subject RIV: ED - Physiology Impact factor: 5.132, year: 2010

  3. Measuring tissue hemodynamics and oxygenation by continuous-wave functional near-infrared spectroscopy—how robust are the different calculation methods against movement artifacts?

    International Nuclear Information System (INIS)

    Continuous-wave near-infrared spectroscopy and imaging enable tissue hemodynamics and oxygenation to be determined non-invasively. Movements of the investigated subject can cause movement artifacts (MAs) in the recorded signals. The strength and type of MAs induced depend on the measurement principle. The aim of the present study was to investigate the quantitative relationship between different single-distance (SD) and multi-distance (MD) measurement methods and their susceptibility to MAs. We found that each method induces MAs to a different degree, and that MD methods are more robust against MAs than SD methods. (paper)

  4. A study on the pathogenesis of human cerebral malaria and cerebral babesiosis

    Directory of Open Access Journals (Sweden)

    Masamichi Aikawa

    1992-01-01

    Full Text Available Cerebral complications are important, but poorly understood pathological features of infections caused by some species of Plasmodium and Babesia. Patients dying from P. falciparum were classified as cerebral or non-cerebral cases according to the cerebral malaria coma scale. Light microscopy revealed that cerebral microvessels of cerebral malaria patients were field with a mixture of parazited and unparazited erythrocytes, with 94% of the vessels showing parasitized red blood cell (PRBC sequestration. Some degree of PRBC sequestration was also found in non-cerebral malaria patients, but the percentage of microvessls with sequestered PRBC was only 13% Electron microscopy demonstrated knobs on the membrane of PRBC that formed focal junctions with the capillary endothelium. A number of host cell molecules such as CD36, thrombospondim (TSP and intracellular adhesion molecule I (ICAM-1 may function as endothelial cell surfacereports for P. falciparum-infected erythrocytes. Affinity labeling of CD36 and TSP to the PRBC surface showed these molecules specifically bind to the knobs. Babesia bovis infected erythrocytes procedure projections of the erythrocyte membrane that are similar to knobs. When brain tissue from B. bovis-infected cattle was examined, cerebral capillaries were packed with PRBC. Infected erythrocytes formed focal attachments with cerebral endothelial cells at the site of these knob-like projections. These findings indicate that cerebral pathology caused by B. bovis is similar to human cerebral malaria. A search for cytoadherence proteins in the endothelial cells may lead to a better understanding of the pathogenisis of cerebral babesiosis.

  5. Tuberculoma cerebral

    OpenAIRE

    BARROSO ELIZABETH CLARA; OLIVEIRA TÂNIA REGINA BRÍGIDO DE; AMARAL ANA MARIA DANTAS DO; PINHEIRO VALÉRIA GÓES FERREIRA; SOUSA ANA LÚCIA DE OLIVEIRA

    2002-01-01

    Relata-se o caso de paciente com crises convulsivas de início recente. A tomografia computadorizada cerebral evidenciou imagem sugestiva de lesão expansiva metastática frontoparietal direita. A investigação de tumor primário ou outra doença foi negativa e o exame histopatológico do tecido cerebral diagnosticou tuberculoma. As convulsões foram controladas com a associação de hidantoína 300mg/dia ao esquema específico, utilizado por 18 meses. A tuberculose do sistema nervoso central representa ...

  6. Iatrogenic systemic air embolism treated with hyperbaric oxygen therapy

    DEFF Research Database (Denmark)

    Jørgensen, Thomas Bech; Sørensen, Allan Martini Ibsen; Jansen, Erik C.

    2008-01-01

    arterial circulation through a shunt, it may cause cerebral emboli with neurological symptoms. We present two cases with venous air emboli and concurrent cerebral arterial emboli. Both patients were successfully treated with hyperbaric oxygen therapy Udgivelsesdato: 2008/4...

  7. Anemia and Oxygen Delivery.

    Science.gov (United States)

    Bliss, Stuart

    2015-09-01

    Clinical assessment of tissue oxygenation is challenging. Anemia reflects a decreased oxygen carrying capacity of the blood and its significance in the perioperative setting relates largely to the associated risk of insufficient oxygen delivery and cellular hypoxia. Until meaningful clinical measures of tissue oxygenation are available in veterinary practice, clinicians must rely on evaluation of a patient's hemodynamic and ventilatory performance, along with biochemical and hemogasometric measurements. Blood transfusion is used commonly for treatment of perioperative anemia, and may improve tissue oxygenation by normalizing the rheologic properties of blood and enhancing perfusion, independent of increases in oxygen carrying capacity. PMID:26033442

  8. Noninvasive functional photoacoustic tomography of blood-oxygen saturation in the brain

    Science.gov (United States)

    Wang, Xueding; Ku, Geng; Xie, Xueyi; Wang, Yiwen; Stoica, George; Wang, Lihong V.

    2004-07-01

    Since optical contrast is sensitive to functional parameters, including the hemoglobin oxygen saturation and the total concentration of hemoglobin, imaging based on optical contrast has been widely employed for the real-time monitoring of tissue oxygen consumption and hemodynamics in biological tissues. However, due to the overwhelming scattering of light in tissues, traditional optical imaging modalities cannot provide satisfactory spatial resolution. Functional photoacoustic tomography is a novel technique that combines high optical contrast and high ultrasonic resolution. Here, we present our study of a laser-based photoacoustic technique that, for the first time to our knowledge, monitors blood oxygenation in the rat brain in vivo. The cerebral blood oxygenation in the rat brain was imaged by photoacoustic detection at two wavelengths. The change in the hemoglobin oxygen saturation in the brain vessels as a result of the alternation from hyperoxia status to hypoxia status was visualized successfully with satisfactory spatial resolution. This work demonstrates that photoacoustic technique, based on the spectroscopic absorption of oxy- and deoxy-hemoglobin, can provide accurate functional imaging of cerebral blood oxygenation in the small-animal brain non-invasively with the skin and skull intact.

  9. In-vivo optical imaging and spectroscopy of cerebral hemodynamics

    Science.gov (United States)

    Zhou, Chao

    Functional optical imaging techniques, such as diffuse optical imaging and spectroscopy and laser speckle imaging (LSI), were used in research and clinical settings to measure cerebral hemodynamics. In this thesis, theoretical and experimental developments of the techniques and their in-vivo applications ranging from small animals to adult humans are demonstrated. Near infrared diffuse optical techniques non-invasively measure hemoglobin concentrations, blood oxygen saturation (diffuse reflectance spectroscopy, DRS) and blood flow (diffuse correlation spectroscopy, DCS) in deep tissues, e.g. brain. A noise model was derived for DCS measurements. Cerebral blood flow (CBF) measured with DCS was validated with arterial-spin-labeling MRI. Three-dimensional CBF tomography was obtained during cortical spreading depression from a rat using the optimized diffuse correlation tomographic method. Cerebral hemodynamics in newborn piglets after traumatic brain injury were continuously monitored optically for six hours to demonstrate the feasibility of using diffuse optical techniques as bedside patient monitors. Cerebral autoregulation in piglets and human stroke patients was demonstrated to be non-invasively assessable via the continuous DCS measurement. Significant differences of CBF responses to head-of-bead maneuvers were observed between the peri- and contra-infarct hemispheres in human stroke patients. A significant portion of patient population showed paradoxical CBF responses, indicating the importance of individualized stroke management. The development of a speckle noise model revealed the source of noise for LSI. LSI was then applied to study the acute functional recovery of the rat brain following transient brain ischemia. The spatial and temporal cerebral blood flow responses to functional stimulation were statistically quantified. The area of activation, and the temporal response to stimulation were found significantly altered by the ischemic insult, while the

  10. Cerebral Arteriosclerosis

    Science.gov (United States)

    ... the brain can cause a hemorrhagic stroke. Both types of stroke can be fatal. Cerebral arteriosclerosis is also related to a condition known as vascular dementia, in which small, symptom-free strokes cause cumulative damage and death to neurons (nerve cells) in the brain. Personality changes in ...

  11. Comparing CT perfusion with oxygen partial pressure in a rabbit VX2 soft-tissue tumor model

    International Nuclear Information System (INIS)

    The aim of this study was to evaluate the oxygen partial pressure of the rabbit model of the VX2 tumor using a 64-slice perfusion CT and to compare the results with that obtained using the oxygen microelectrode method. Perfusion CT was performed for 45 successfully constructed rabbit models of a VX2 brain tumor. The perfusion values of the brain tumor region of interest, the blood volume (BV), the time to peak (TTP) and the peak enhancement intensity (PEI) were measured. The results were compared with the partial pressure of oxygen (PO2) of that region of interest obtained using the oxygen microelectrode method. The perfusion values of the brain tumor region of interest in 45 successfully constructed rabbit models of a VX2 brain tumor ranged from 1.3–127.0 (average, 21.1 ± 26.7 ml/min/ml); BV ranged from 1.2–53.5 ml/100g (average, 22.2 ± 13.7 ml/100g); PEI ranged from 8.7–124.6 HU (average, 43.5 ± 28.7 HU); and TTP ranged from 8.2–62.3 s (average, 38.8 ± 14.8 s). The PO2 in the corresponding region ranged from 0.14–47 mmHg (average, 16 ± 14.8 mmHg). The perfusion CT positively correlated with the tumor PO2, which can be used for evaluating the tumor hypoxia in clinical practice. (author)

  12. Cerebral hemodynamics in aging : the interplay between blood pressure, cerebral perfusion, and dementia

    OpenAIRE

    Claassen, J.A.H.R.

    2008-01-01

    Advances in measurement techniques have made it possible to study dynamic changes in brain blood flow. Transcranial Doppler ultrasonography measures changes in cerebral blood flow-velocity in the larger cerebral arteries (e.g. the middle cerebral artery). Near infrared spectroscopy records changes in brain cortical tissue concentrations of hemoglobin. These techniques are non-invasive, and can be performed with the subject in supine, sitting or standing position. Together with photoplethysmog...

  13. Myogenic and metabolic feedback in cerebral autoregulation: Putative involvement of arachidonic acid-dependent pathways.

    Science.gov (United States)

    Berg, Ronan M G

    2016-07-01

    The present paper presents a mechanistic model of cerebral autoregulation, in which the dual effects of the arachidonic acid metabolites 20-hydroxyeicosatetraenoic acid (20-HETE) and epoxyeicosatrienoic acids (EETs) on vascular smooth muscle mediate the cerebrovascular adjustments to a change in cerebral perfusion pressure (CPP). 20-HETE signalling in vascular smooth muscle mediates myogenic feedback to changes in vessel wall stretch, which may be modulated by metabolic feedback through EETs released from astrocytes and endothelial cells in response to changes in brain tissue oxygen tension. The metabolic feedback pathway is much faster than 20-HETE-dependent myogenic feedback, and the former thus initiates the cerebral autoregulatory response, while myogenic feedback comprises a relatively slower mechanism that functions to set the basal cerebrovascular tone. Therefore, assessments of dynamic cerebral autoregulation, which may provide information on the response time of the cerebrovasculature, may specifically be used to yield information on metabolic feedback mechanisms, while data based on assessments of static cerebral autoregulation represent the integrated functionality of myogenic and metabolic feedback. PMID:27241246

  14. Non-invasive measurements of tissue hemodynamics with hybrid diffuse optical methods

    Science.gov (United States)

    Durduran, Turgut

    Diffuse optical techniques were used to measure hemodynamics of tissues non-invasively. Spectroscopy and tomography of the brain, muscle and implanted tumors were carried out in animal models and humans. Two qualitatively different methods, diffuse optical tomography and diffuse correlation tomography, were hybridized permitting simultaneous measurement of total hemoglobin concentration, blood oxygen saturation and blood flow. This combination of information was processed further to derive estimates of oxygen metabolism (e.g. CMRO 2) in tissue. The diffuse correlation measurements of blood flow were demonstrated in human tissues, for the first time, demonstrating continous, non-invasive imaging of oxygen metabolism in large tissue volumes several centimeters below the tissue surface. The bulk of these investigations focussed on cerebral hemodynamics. Extensive validation of this methodology was carried out in in vivo rat brain models. Three dimensional images of deep tissue hemodynamics in middle cerebral artery occlusion and cortical spreading depression (CSD) were obtained. CSD hemodynamics were found to depend strongly on partial pressure of carbon dioxide. The technique was then adapted for measurement of human brain. All optical spectroscopic measurements of CMRO2 during functional activation were obtained through intact human skull non-invasively. Finally, a high spatio-temporal resolution measurement of cerebral blood flow due to somatosensory cortex activation following electrical forepaw stimulation in rats was carried out with laser speckle flowmetry. New analysis methods were introduced for laser speckle flowmetry. In other organs, deep tissue hemodynamics were measured on human calf muscle during exercise and cuff-ischemia and were shown to have some clinical utility for peripheral vascular disease. In mice tumor models, the measured hemodynamics were shown to be predictive of photodynamic therapy efficacy, again suggesting promise of clinical utility

  15. The effect of phenylephrine on arterial and venous cerebral blood flow in healthy subjects

    DEFF Research Database (Denmark)

    Ogoh, Shigehiko; Sato, Kohei; Fisher, James P; Seifert, Thomas; Overgaard, Morten; Secher, Niels H

    2011-01-01

    Sympathetic regulation of the cerebral circulation remains controversial. Although intravenous phenylephrine (PE) infusion reduces the near-infrared spectroscopy (NIRS)-determined measure of frontal lobe oxygenation (S(c) O(2) ) and increases middle cerebral artery mean blood velocity (MCA V(mean......(mean) ), suggesting α-adrenergic-mediated cerebral vasoconstriction, this remains unconfirmed by evaluation of arterial and venous cerebral blood flow.......Sympathetic regulation of the cerebral circulation remains controversial. Although intravenous phenylephrine (PE) infusion reduces the near-infrared spectroscopy (NIRS)-determined measure of frontal lobe oxygenation (S(c) O(2) ) and increases middle cerebral artery mean blood velocity (MCA V...

  16. Unchanged cerebral blood flow and oxidative metabolism after acclimatization to high altitude

    DEFF Research Database (Denmark)

    Møller, Kirsten; Paulson, Olaf B; Hornbein, Thomas F.;

    2002-01-01

    . Global cerebral blood flow at rest and during exercise on a bicycle ergometer was measured by the Kety-Schmidt technique. Cerebral metabolic rates of oxygen, glucose, and lactate were calculated by the Fick principle. Cerebral function was assessed by a computer-based measurement of reaction time...... and cerebral metabolic rates of oxygen and glucose also remained unchanged, whereas cerebral metabolic rates of lactate increased slightly but nonsignificantly at high altitude during exercise compared with high altitude at rest. Reaction time was unchanged. The data indicate that cerebral blood flow...... and oxidative metabolism are unaltered after high-altitude acclimatization from sea level, despite marked changes in breathing and other organ functions....

  17. Cerebral near infrared spectroscopy oximetry in extremely preterm infants

    DEFF Research Database (Denmark)

    Hyttel-Sorensen, Simon; Pellicer, Adelina; Alderliesten, Thomas;

    2015-01-01

    ultrasonography. RANDOMISATION: Allocation sequence 1:1 with block sizes 4 and 6 in random order concealed for the investigators. The allocation was stratified for gestational age (<26 weeks or ≥ 26 weeks). BLINDING: Cerebral oxygenation measurements were blinded in the control group. All outcome assessors were......OBJECTIVE: To determine if it is possible to stabilise the cerebral oxygenation of extremely preterm infants monitored by cerebral near infrared spectroscopy (NIRS) oximetry. DESIGN: Phase II randomised, single blinded, parallel clinical trial. SETTING: Eight tertiary neonatal intensive care units...... infants using a dedicated treatment guideline in combination with cerebral NIRS monitoring.Trial registration ClinicalTrial.gov NCT01590316....

  18. Effects of In Vitro Low Oxygen Tension Preconditioning of Adipose Stromal Cells on Their In Vivo Chondrogenic Potential: Application in Cartilage Tissue Repair

    Science.gov (United States)

    Gauthier, Olivier; Lesoeur, Julie; Sourice, Sophie; Masson, Martial; Fellah, Borhane Hakim; Geffroy, Olivier; Lallemand, Elodie; Weiss, Pierre

    2013-01-01

    Purpose Multipotent stromal cell (MSC)-based regenerative strategy has shown promise for the repair of cartilage, an avascular tissue in which cells experience hypoxia. Hypoxia is known to promote the early chondrogenic differentiation of MSC. The aim of our study was therefore to determine whether low oxygen tension could be used to enhance the regenerative potential of MSC for cartilage repair. Methods MSC from rabbit or human adipose stromal cells (ASC) were preconditioned in vitro in control or chondrogenic (ITS and TGF-β) medium and in 21 or 5% O2. Chondrogenic commitment was monitored by measuring COL2A1 and ACAN expression (real-time PCR). Preconditioned rabbit and human ASC were then incorporated into an Si-HPMC hydrogel and injected (i) into rabbit articular cartilage defects for 18 weeks or (ii) subcutaneously into nude mice for five weeks. The newly formed tissue was qualitatively and quantitatively evaluated by cartilage-specific immunohistological staining and scoring. The phenotype of ASC cultured in a monolayer or within Si-HPMC in control or chondrogenic medium and in 21 or 5% O2 was finally evaluated using real-time PCR. Results/Conclusions 5% O2 increased the in vitro expression of chondrogenic markers in ASC cultured in induction medium. Cells implanted within Si-HPMC hydrogel and preconditioned in chondrogenic medium formed a cartilaginous tissue, regardless of the level of oxygen. In addition, the 3D in vitro culture of ASC within Si-HPMC hydrogel was found to reinforce the pro-chondrogenic effects of the induction medium and 5% O2. These data together indicate that although 5% O2 enhances the in vitro chondrogenic differentiation of ASC, it does not enhance their in vivo chondrogenesis. These results also highlight the in vivo chondrogenic potential of ASC and their potential value in cartilage repair. PMID:23638053

  19. Effects of Hyperoxia on Brain Tissue Oxygen Tension in Non-Sedated, Non- Anesthetized Arctic Ground Squirrels: An Animal Model of Hyperoxic Stress

    Directory of Open Access Journals (Sweden)

    Y. Ma

    2011-01-01

    Full Text Available Arctic Ground Squirrels (AGS are classic hibernators known for their tolerance to hypoxia. AGS have been studied as a model of hypoxia with potential as a medical research model. Problem statement: Their unique resistance to the stressors of low oxygen led us to hypothesize that AGS might also be adaptable to hyperoxia. Approach: This study examined the physiological pattern associated with hyperoxia in response to brain tissue oxygen partial pressure (PtO2, brain temperature (Tbrain, global oxygen consumption (VO2 and respiratory frequency (fR using non-sedated and nonanesthetized Arctic Ground Squirrels (AGS and rats. Results: We found that 1 100% inspired oxygen (FiO2 increased the baseline values of brain PtO2 significantly in both summer euthermic AGS (24.4 ± 3.6-87.3 ± 3.6 mmHg, n=6 and in rats (18.2 ± 5.2-73.3 ± 5.2 mmHg, n = 3; PtO2 was significantly higher in AGS than in rats during hyperoxic exposure; 2 hyperoxic exposure had no effect on brain temperature in either AGS or rats, with the brain temperatures maintaining constancy before, during and after 100% O2 exposure; 3 systemic metabolic rates increased significantly during hyperoxic exposure in both euthermic AGS and rats; moreover, VO2 were significantly lower in AGS than in rats during hyperoxic exposure; 4 the respiratory rates for rats were maintained before, during and after 100% O2 exposure, while the respiratory responding patterns to hyperoxic exposure changed after exposure in AGS. AGS fR was significantly lower after hyperoxic exposure than before the exposure. Conclusion: These results suggest that hyperoxic ventilation induced PtO2 and VO2 differences between AGS and rats and led to altered respiratory patterns between these species. AGS and the rat serves as an excellent comparative model for hypoxic and hyperoxic stress studies of the brain.

  20. Effects of reactive oxygen species on metabolism monitored by longitudinal {sup 1}H single voxel MRS follow-up in patients with mitochondrial disease or cerebral tumors

    Energy Technology Data Exchange (ETDEWEB)

    Constans, J M; Collet, S; Hossu, G; Courtheoux, P [MRI Unit, Caen University Hospital, Caen, Normandy (France); Guillamo, J S; Lechapt-Zalcman, E; Valable, S [CERVOxy Group, CI-NAPS, UMR 6232 CI-NAPS, Cyceron, Caen, Normandy (France); Lacombe, S; Houee Levin, C [Paris-Sud 11 University-CNRS, Orsay (France); Gauduel, Y A [LOA, Ecole Polytechnique - ENSTA ParisTech, Palaiseau (France); Dou, W [Tsinghua University, Beijing (China); Ruan, S [CReSTIC EA 3804, IUT Troyes, Troyes (France); Barre, L [GDMTEP, Group CI-NAPS, UMR 6232 CI-NAPS, Cyceron, Caen (France); Rioult, F [CNRS UMR 6072, GREYC, Caen, Normandy (France); Derlon, J M [Neurosurgery and Neurology, Caen University Hospital, Caen, Normandy (France); Chapon, F [Pathology, Caen University Hospital, Caen, Normandy (France); Fong, V [Caen University (France); Kauffmann, F, E-mail: constans-jm@chu-caen.fr [Mathematics LMNO CNRS UMR 6139, Caen University, Caen, Normandy (France)

    2011-01-01

    Free radicals, or Reactive Oxygen Species (ROS), have an effect on energy and glycolytic metabolism, mitochondrial function, lipid metabolism, necrosis and apoptosis, cell proliferation, and infiltration. These changes could be monitored longitudinally (every 4 months over 6 years) in humans with glial brain tumors (low and high grade) after therapy, using conventional magnetic resonance imaging (MRI) and spectroscopy (MRS) and MR perfusion. Some examples of early clinical data from longitudinal follow-up monitoring in humans of energy and glycolytic metabolism, lipid metabolism, necrosis, proliferation, and infiltration measured by conventional MRI, MRS and perfusion, and positron emission tomography (PET) are shown in glial brain tumors after therapy. Despite the difficulty, the variability and unknown factors, these repeated measurements give us a better insight into the nature of the different processes, tumor progression and therapeutic response.

  1. 早期高压氧及针灸治疗高血压性脑出血术后脑及肢体功能障碍%The effect of early hyperbaric oxygen and acupuncture on hypertension patients with cerebral hemorrhage and limb dysfunction

    Institute of Scientific and Technical Information of China (English)

    林志忠; 李万川; 黄镔霖; 张和平; 余惠平

    2001-01-01

    Objective To evaluate the rehabilitation therapy for the patient with hypertensive cerebral hemorrhage after operation.Method All cases suffered from hyperensive cerebral hemorrhage are divided into two groups,the rehabiliatation therapy group(the one with both early hyperbaric oxygen and the early acupuncture ),the common therapy group(the one neither with hyperbaric oxygen nor with acupuncture).Result 93 cases in rehabilitation therapy group are favourable(ADL:1~3).14 cases in common therapy group are favourable.The outcome of the rehabilitation therapy group is better than that of the latter(P<0.05). Conclusion The early treatment by hyperbaric oxygen and acupuncturewill promoted the rehabilitation of the patient suffered from hypertensive cerebral hemorrhage after operation.%目的 讨高血压脑出血术后脑及肢体功能障碍的康复治疗。方法康复治疗组行早期高压氧及针灸等治疗,对照组单纯药物治疗。结果 DL1~3级康复治疗组93例,对照组14例,康复治疗组优于对照组,P<0.05。结论 期高压氧及针灸治疗,有利于高血压脑出血术后康复。

  2. 早期高压氧及针灸治疗高血压性脑出血术后脑及肢体功能障碍%The effect of early hyperbaric oxygen and acupuncture on hypertension patients with cerebral hemorrhage and limb dysfunction

    Institute of Scientific and Technical Information of China (English)

    林志忠; 李万川; 黄镔霖; 张和平; 余惠平

    2001-01-01

    Objective To evaluate the rehabilitation therapy for the patientwith hypertensive cerebral hemorrhage after operation.Method All cases suffered from hyperensive cerebral hemorrhage are divided into two groups,the rehabiliatation therapy group(the one with both early hyperbaric oxygen and the early acupuncture ),the common therapy group(the one neither with hyperbaric oxygen nor with acupuncture).Result 93 cases in rehabilitation therapy group are favourable(ADL:1~3).14 cases in common therapy group are favourable.The outcome of the rehabilitation therapy group is better than that of the latter(P<0.05). Conclusion The early treatment by hyperbaric oxygen and acupuncturewill promoted the rehabilitation of the patient suffered from hypertensive cerebral hemorrhage after operation.%目的 探讨高血压脑出血术后脑及肢体功能障碍的康复治疗。方法康复治疗组行早期高压氧及针灸等治疗,对照组单纯药物治疗。结果 DL1~3级康复治疗组93例,对照组14例,康复治疗组优于对照组,P<0.05。结论 期高压氧及针灸治疗,有利于高血压脑出血术后康复。

  3. Should Cerebral Near-infrared Spectroscopy be Standard of Care in Adult Cardiac Surgery?

    Science.gov (United States)

    Bevan, Priscilla J W

    2015-06-01

    Near-infrared spectroscopy (NIRS) is non-invasive, easy to use, and offers real-time monitoring of the oxygen content of cerebral tissue. An effective and user-friendly method of cerebral monitoring stands to offer a significant advance in patient care during adult cardiac surgery, particularly for surgery in which the continuity of cerebral vessels may be compromised. While the current evidence does not definitively show improvement in neurological outcomes, it can be argued that the overall risk to benefit ratio falls on the side of NIRS. NIRS also gives information about the oxygenation of systemic tissues. It may be that in surgery that does not involve the aortic arch, the value of NIRS will be in increased individualisation of patient management and improved systemic perfusion, impacting general outcomes as much as neurological outcomes. This review will summarise the need for neuromonitoring and the principles of NIRS. It will examine the thresholds used to define desaturation, the evidence for clinical benefit from NIRS, and the criticisms and limitations of NIRS. It will also discuss the uses of NIRS beyond improving neurological outcomes alone. PMID:25735719

  4. The Effects of a Home-Based Connective Tissue Targeting Therapy on Hip Development in Children With Cerebral Palsy: Six Case Reports.

    Science.gov (United States)

    Drewes, Erika; Driscoll, Mark; Blyum, Leonid; Vincentz, Diane

    2016-01-01

    Hip subluxation in children with Cerebral Palsy (CP) has an incidence of 10-30 %, and children with severe CP having the highest incidence. The condition deteriorates if left untreated. Surgery is the most common method used in managing hip subluxation because standard conservative therapies do not improve it. Surgery may have to be repeated and comes at a biological cost to the child. A new home-based CAM, Advanced Biomechanical Rehabilitation (ABR), has shown encouraging results leading to improved spinal stability and stability in sitting in children with severe CP. This case report examines hip development over time in six children with severe CP in the ABR Program. Changes in their clinical picture and pelvic X-Rays are reported. ABR appeared to help stabilize and improve hip subluxation, resulting in these children not requiring further surgical intervention. These findings warrant further investigation of ABR as a noninvasive therapy for hip subluxation. PMID:27198038

  5. Study of cerebral oxygen metabolism in patients with acute severe craniocerebral injury%特重度颅脑损伤患者急性期脑氧代谢变化的研究

    Institute of Scientific and Technical Information of China (English)

    鹿中华; 孙昀; 李惠; 郑瑶; 汤艳

    2012-01-01

    Objective To study the changes of brain oxygen metabolism in patients with acute severe craniocerebral injury, and the influence on the prognosis of the patients. Methods A total of 27 patients with acute severe craniocerebral injury were selected from June 2009 to July 2011 in ICU, their blood from jugular vein and radial artery was collected, the blood gas analysis were performed and blood sugar were assayed. The cerebral oxygen utilization coefficients (02Ucc), and difference of CO2 partial pressure (V-APCO2), lactic acid (V- ALac) and blood sugar (V-AGlu) between jugular vein and radial artery were calculated and O2 suturation of jugular venous blood (SjvO2) were determined. All patients were divided into the survival group and the death group according to the early prognosis, and the index was compared between two groups. Results Compared with the death group, the V-ALac was lower in the survival group significantly (P 0.05). Conclusion The changes of cerebral oxygen metabolism exist in patients with acute severe craniocerebral injury. 02Ucc, V-ALac, V-APCO2, SjvO2 can be used as indices of the prognosis evaluation.%目的探讨特重度颅脑损伤患者早期脑氧代谢变化及其对患者预后的影响.方法自2009年6月至2011年7月ICU治疗的27例特重度颅脑损伤患者,采集其颈静脉与桡动脉血进行血气分析及血葡萄糖测定,计算脑氧利用率(O2Ucc),以及颈内静脉与动脉血二氧化碳分压差(V-APCO2)、血乳酸差(V-ALac)、血糖差(V-AGlu)的绝对值和颈内静脉血氧饱和度(SjvO2),根据近期预后将患者分为存活组和死亡组,对两组患者上述观察指标进行比较.结果与死亡组比较,存活组V-ALac显著降低(P0.05).结论特重度颅脑损伤患者早期存在脑氧代谢异常,O2Ucc、V-ALac、V-APCO2、SjvO2等指标可作为评估患者预后的指标.

  6. Edaravone (MCI-186) scavenges reactive oxygen species and ameliorates tissue damage in the murine spinal cord injury model.

    Science.gov (United States)

    Aoyama, Takeshi; Hida, Kazutoshi; Kuroda, Satoshi; Seki, Toshitaka; Yano, Shunsuke; Shichinohe, Hideo; Iwasaki, Yoshinobu

    2008-12-01

    The present study evaluated the effect of the free radical scavenger edaravone on lesion volume and neurological dysfunction after spinal cord injury (SCI) in mice, and investigated its protective effects on superoxide generation. Female C57BL/6 mice were subjected to SCI using a pneumatic impact device and were treated with 3 mg/kg of edaravone or vehicle 30 minutes before the insult. Motor functions were quantitatively evaluated. Lesion volume was assessed by Dohrmann's two-cone method after one week. In situ detection of superoxide in the injured cord was carried out using the superoxide-sensitive dye dihydroethidium (DHE) staining technique. Pretreatment with edaravone significantly improved motor dysfunction and reduced the lesion volume to about 63% of the control (p scavenging reactive oxygen species, especially in the neurons, after SCI. PMID:19106491

  7. Photodynamic treatment of the RIF-1 tumor with verteporfin with online monitoring of tissue oxygen using electron paramagnetic resonance oximetry

    Science.gov (United States)

    Pogue, Brian W.; O'Hara, Julia A.; Liu, Ke J.; Hasan, Tayyaba; Swartz, Harold

    1999-06-01

    In this study, treatment of the RIF-1 tumor was examined with photodynamic therapy using Verteprofin (formerly benzoporphyrin derivative, BPD). The effects of two different optical dose rates were examined, with no detectable difference in the tumor regrowth time. Oxygen consumption during PDT could reliably be monitored with electron paramagnetic resonance (EPR) oximetry using an implanted paramagnetic material within the tumor. A reduction of the tumor pO2 was detected in the animals that were followed after treatment, suggesting that there was a compromise to the tumor vasculature that persisted throughout the measurements. At high total doses some of the tumors did not regrow. Altogether these results are indicative of the tumor destruction being caused by destruction of the blood vessels from the treatment.

  8. Employees with Cerebral Palsy

    Science.gov (United States)

    ... Resources Home | Accommodation and Compliance Series: Employees with Cerebral Palsy (CP) By Eddie Whidden, MA Preface Introduction Information ... SOAR) at http://AskJAN.org/soar. Information about Cerebral Palsy (CP) What is CP? Cerebral palsy is a ...

  9. Changes of regional cerebral blood oxygenation in recognizing Chinese characters in children with Chinese dyslexia%汉语阅读障碍儿童汉字识别过程中脑血氧的变化

    Institute of Scientific and Technical Information of China (English)

    宋然然; 吴汉荣

    2006-01-01

    化量明显高于对照组(0.073 0,-0.072 1,F=15.59,P<0.01).结论:汉字认知过程阅读障碍儿童左前额叶皮层虽然激活,但相对正常儿童,激活的程度和激活模式均有差异,提示特定脑区功能异常可能是阅读障碍发生的生物学基础.%BACKGROUND: Dyslexia is the most common in the study of learning disabilities, it can affect various aspects of children, including behaviors,cognition, emotion, social adaptation, etc., and seriously block their obtaining of knowledge and improvement of ability in children.OBJECTIVE: To study the changing law of regional cerebral blood oxygenation in children with Chinese dyslexia in the process of recognizing Chinese characters, and investigate the neurophysiological basis of dyslexia in children.DESIGN: A case-control study.SETTING: Department of Child and Adolescent Health and Maternal Care, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology.PARTICIPANTS: The study was carried out in Huazhong University of Science and Technology from June to September in 2003. Forty-five primary students of 8 to 12 years old, who were grade 3 to 5 in Wuhan city,were enrolled in this study, including 26 dyslexic children (dyslexia group)and 19 normal readers (control group). All the enrolled children were righthanded. Informed consents were obtained from all the participants and their parents (guardians) after explanation of aims and steps of this study.METHODS: The functional near-infrared imager (fNIRI) was applied to detect the changes of cerebral blood oxygenation in left prefrontal lobe of dyslexic children and normal children in the primary processing (viewing passively, reading aloud, producing an action word) and secondary processing of Chinese characters (outputting task, action words association) of Chinese characters.MAIN OUTCOME MEASURES: The changes of cerebral blood oxygenation in the primary processing and secondary processing of Chinese characters were observed in both

  10. In vivo measurements of regional hemoglobin oxygen saturation values and limb-to-arm ratios of near-infrared spectroscopy for tissue oxygenation monitoring of lower extremities in healthy subjects

    Directory of Open Access Journals (Sweden)

    Boezeman RP

    2014-12-01

    Full Text Available Reinout PE Boezeman,1 Johannes C Kelder,2 Frans GJ Waanders,3 Frans L Moll,4 Jean-Paul PM de Vries1 1Department of Vascular Surgery, St Antonius Hospital, Nieuwegein, the Netherlands; 2Department of Research and Developments, St Antonius Hospital, Nieuwegein, the Netherlands; 3Department of Perfusion, St Antonius Hospital, Nieuwegein, the Netherlands; 4Department of Vascular Surgery, University Medical Center Utrecht, Utrecht, the Netherlands Objective: Near-infrared spectroscopy (NIRS is a noninvasive technique that allows monitoring of regional hemoglobin oxygen saturation (rSO2 values and might have a role in the diagnosis of peripheral arterial disease. We assessed the reproducibility and inter-subject variability of rSO2 values and rSO2 limb-to-arm ratios (LARs in lower extremities of healthy subjects. Methods: The rSO2 values and rSO2 LARs were calculated in eight healthy subjects without peripheral arterial disease. The rSO2 values were measured at rest at six fixed spots at each lower limb and a reference spot at each upper arm. NIRS provided the rSO2 values without involvement of any other processing technique. After measurements were completed, rSO2 LARs were calculated by dividing the rSO2 value of a lower extremity spot by the rSO2 value of the arm. Measurements were performed twice on 1 day and repeated on 4 different days. Results: Mean coefficients of variation of measurements of rSO2 values and rSO2 LARs at the same spot in the same subject were respectively less than 6% and 8% for every measurement spot over time. Coefficients of variation of measurements at the same spot between different subjects were less than 15% and 19% for every measurement spot respectively. Conclusion: NIRS is an easily applicable, noninvasive tool for measurement of tissue oxygenation of lower extremities in healthy subjects. The reproducibility of rSO2 values and rSO2 LARs at the same measurement spot in the same subject is good. Keywords: NIRS, rSO2

  11. Susceptibility weighted imaging of stroke brain in response to normobaric oxygen (NBO) therapy

    Science.gov (United States)

    Zhou, Iris Y.; Igarashi, Takahiro; Guo, Yingkun; Sun, Phillip Z.

    2015-03-01

    The neuroprotective effect of oxygen leads to recent interest in normobaric oxygen (NBO) therapy after acute ischemic stroke. However, the mechanism remains unclear and inconsistent outcomes were reported in human studies. Because NBO aims to improve brain tissue oxygenation by enhancing oxygen delivery to ischemic tissue, monitoring the oxygenation level changes in response to NBO becomes necessary to elucidate the mechanism and to assess the efficacy. Susceptibility weighted imaging (SWI) which provides a new MRI contrast by combining the magnitude and phase images is fit for purpose. SWI is sensitive to deoxyhemoglobin level changes and thus can be used to evaluate the cerebral metabolic rate of oxygen. In this study, SWI was used for in vivo monitoring of oxygenation changes in a rat model of permanent middle cerebral artery occlusion (MCAO) before, during and after 30 min of NBO treatment. Regions of interest in ischemic core, penumbra and contralateral normal area were generated based on diffusionweighted imaging and perfusion imaging. Significant differences in SWI indicating different oxygenation levels were generally found: contralateral normal > penumbra > ischemic core. Ischemic core showed insignificant increase in oxygenation during NBO and returned to pre-treatment level after termination of NBO. Meanwhile, the oxygenation levels slightly increased in contralateral normal and penumbra regions during NBO and significantly decreased to a level lower than pre-treatment after termination of NBO, indicating secondary metabolic disruption upon the termination of transient metabolic support from oxygen. Further investigation of NBO effect combined with reperfusion is necessary while SWI can be used to detect hemorrhagic transformation after reperfusion.

  12. Quantitative spatially resolved measurement of tissue chromophore concentrations using photoacoustic spectroscopy: application to the measurement of blood oxygenation and haemoglobin concentration

    International Nuclear Information System (INIS)

    A new approach based on pulsed photoacoustic spectroscopy for non-invasively quantifying tissue chromophore concentrations with high spatial resolution has been developed. The technique is applicable to the quantification of tissue chromophores such as oxyhaemoglobin (HbO2) and deoxyhaemoglobin (HHb) for the measurement of physiological parameters such as blood oxygen saturation (SO2) and total haemoglobin concentration. It can also be used to quantify the local accumulation of targeted contrast agents used in photoacoustic molecular imaging. The technique employs a model-based inversion scheme to recover the chromophore concentrations from photoacoustic measurements. This comprises a numerical forward model of the detected time-dependent photoacoustic signal that incorporates a multiwavelength diffusion-based finite element light propagation model to describe the light transport and a time-domain acoustic model to describe the generation, propagation and detection of the photoacoustic wave. The forward model is then inverted by iteratively fitting it to measurements of photoacoustic signals acquired at different wavelengths to recover the chromophore concentrations. To validate this approach, photoacoustic signals were generated in a tissue phantom using nanosecond laser pulses between 740 nm and 1040 nm. The tissue phantom comprised a suspension of intralipid, blood and a near-infrared dye in which three tubes were immersed. Blood at physiological haemoglobin concentrations and oxygen saturation levels ranging from 2% to 100% was circulated through the tubes. The signal amplitude from different temporal sections of the detected photoacoustic waveforms was plotted as a function of wavelength and the forward model fitted to these data to recover the concentrations of HbO2 and HHb, total haemoglobin concentration and SO2. The performance was found to compare favourably to that of a laboratory CO-oximeter with measurement resolutions of ±3.8 g l-1 (±58 μM) and ±4

  13. Quantitative spatially resolved measurement of tissue chromophore concentrations using photoacoustic spectroscopy: application to the measurement of blood oxygenation and haemoglobin concentration

    Energy Technology Data Exchange (ETDEWEB)

    Laufer, Jan; Delpy, Dave; Elwell, Clare; Beard, Paul [Department of Medical Physics and Bioengineering, University College London, Malet Place Engineering Building, London WC1E 6BT (United Kingdom)

    2007-01-07

    A new approach based on pulsed photoacoustic spectroscopy for non-invasively quantifying tissue chromophore concentrations with high spatial resolution has been developed. The technique is applicable to the quantification of tissue chromophores such as oxyhaemoglobin (HbO{sub 2}) and deoxyhaemoglobin (HHb) for the measurement of physiological parameters such as blood oxygen saturation (SO{sub 2}) and total haemoglobin concentration. It can also be used to quantify the local accumulation of targeted contrast agents used in photoacoustic molecular imaging. The technique employs a model-based inversion scheme to recover the chromophore concentrations from photoacoustic measurements. This comprises a numerical forward model of the detected time-dependent photoacoustic signal that incorporates a multiwavelength diffusion-based finite element light propagation model to describe the light transport and a time-domain acoustic model to describe the generation, propagation and detection of the photoacoustic wave. The forward model is then inverted by iteratively fitting it to measurements of photoacoustic signals acquired at different wavelengths to recover the chromophore concentrations. To validate this approach, photoacoustic signals were generated in a tissue phantom using nanosecond laser pulses between 740 nm and 1040 nm. The tissue phantom comprised a suspension of intralipid, blood and a near-infrared dye in which three tubes were immersed. Blood at physiological haemoglobin concentrations and oxygen saturation levels ranging from 2% to 100% was circulated through the tubes. The signal amplitude from different temporal sections of the detected photoacoustic waveforms was plotted as a function of wavelength and the forward model fitted to these data to recover the concentrations of HbO{sub 2} and HHb, total haemoglobin concentration and SO{sub 2}. The performance was found to compare favourably to that of a laboratory CO-oximeter with measurement resolutions of {+-}3

  14. 丙泊酚靶控输注诱导气管插管对腹腔镜手术患者脑氧平衡及代谢的影响%Influence on cerebral oxygen balance and metabolism of propofol target controlled infusion induced tracheal intubation in patients with laparoscopic surgery

    Institute of Scientific and Technical Information of China (English)

    廖亿粦; 魏伟; 黄典

    2014-01-01

    the laparoscopic surgery in patients with cerebral oxygen metabolism and the brain tissue of ischemia hypoxia tolerance,but will not lead to cerebral oxygen supply and demand imbalance,and 7 μ g/ml concentration of propofol anesthesia effect is the best.%目的 探讨丙泊酚靶控输注诱导气管插管对腹腔镜手术患者脑氧平衡及代谢的影响.方法 选取2012年1月至2013年10月择期行妇科腹腔镜手术患者96例,所有患者均在丙泊酚靶控输注麻醉诱导下行颈内静脉逆行穿刺置管至右侧颈内静脉球部,行桡动脉置管.根据丙泊酚靶控输注的目标浓度分为A组32例、B组33例和C组31例,浓度分别为3,5,7μg/ml.监测患者手术过程中血流动力学及Nacotrend指数(NI)变化,分别于诱导前(T0)、插管即刻(T1)、插管后30 min(T2)、术毕(T3)收集患者颈内静脉和桡动脉血进行血气分析,比较三组患者不同时间点的动脉血氧分压(PaO2)、动脉血氧含量(CaO2)、颈内静脉球部血氧饱和度(SjvO2)、颈内静脉球部血氧分压(PjvO2),计算三组动脉-颈内静脉球部血氧差(Da-jvO2)、脑氧摄取率(CEO2)、乳酸含量差(Da-jvL).结果 三组患者收缩压、心率和NI在T1和T2时均明显低于To,差异有统计学意义(P<0.05),而三组患者T1、T2时的NI比较差异有统计学意义(P<0.05).与To比较,三组患者的PaO2、PjvO2、SjvO2和CaO2在T1~T3明显升高(P<0.05),且三组数值均以C组最高,B组次之,A组最低.在丙泊酚靶控输注过程中,Da-jvO2、CEO2和Da-jvL均呈现逐渐下降的趋势,其中以Da-jvL下降趋势最为明显,差异有统计学意义(P<0.05).结论 丙泊酚靶控输注诱导气管插管可降低腹腔镜手术患者的脑氧代谢速度,增加脑组织对缺血缺氧的耐受性,但并不会导致患者出现脑氧供需失衡,其中以7μg/ml丙泊酚浓度的麻醉效果最佳.

  15. The effect of herbs on cerebral energy metabolism in cerebral ischemia-reperfusion mice

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@Vascular dementia is one of the most familiar types of senile dementia. Over the past few years, the research on the damage of cerebral tissues after ischemia has become a focus. The factors and mechanism of cerebral tissue damage after ischemia are very complex. The handicap of energy metabolism is regarded as the beginning factor which leads to the damage of neurons, but its dynamic changes in ischemic area and its role during the process of neuronal damage are not very clear. There are few civil reports on using 31 P nuclear magnetic resonance instrument to explore the changes of cerebral energy metabolism in intravital animals. After exploring the influence of herbs on cerebral energy metabolism in ischemia-reperfusion mice, we came to the conclusion that herbs can improve the cerebral energy metabolism in ischemia-reperfusion mice.

  16. Dynamic oxygen-enhanced MRI of cerebrospinal fluid.

    Directory of Open Access Journals (Sweden)

    Taha M Mehemed

    Full Text Available Oxygen causes an increase in the longitudinal relaxation rate of tissues through its T1-shortening effect owing to its paramagnetic properties. Due to such effects, MRI has been used to study oxygen-related signal intensity changes in various body parts including cerebrospinal fluid (CSF space. Oxygen enhancement of CSF has been mainly studied using MRI sequences with relatively longer time resolution such as FLAIR, and T1 value calculation. In this study, fifteen healthy volunteers were scanned using fast advanced spin echo MRI sequence with and without inversion recovery pulse in order to dynamically track oxygen enhancement of CSF. We also focused on the differences of oxygen enhancement at sulcal and ventricular CSF. Our results revealed that CSF signal after administration of oxygen shows rapid signal increase in both sulcal CSF and ventricular CSF on both sequences, with statistically significant predominant increase in sulcal CSF compared with ventricular CSF. CSF is traditionally thought to mainly form from the choroid plexus in the ventricles and is absorbed at the arachnoid villi, however, it is also believed that cerebral arterioles contribute to the production and absorption of CSF, and controversy remains in terms of the precise mechanism. Our results demonstrated rapid oxygen enhancement in sulcal CSF, which may suggest inhaled oxygen may diffuse into sulcal CSF space rapidly probably due to the abundance of pial arterioles on the brain sulci.

  17. Advances in the Management of Cerebral Vascular Disease

    OpenAIRE

    Muhammad Imran Qadir; Hina Kanwal

    2015-01-01

    A cerebral vascular disease occurred with the arteries of brain due to the less supply of blood.  Stroke is mostly caused by cerebral vascular disease and it is also a common cause of vascular dementia due to reduced oxygen supply and blood flow to the brain. In industrialized countries, neurologic disability is most frequently caused by cerebeovascular disease. Individuals with cardiovascular disease, diabetes and high blood pressure etc are at higher possibility for cerebral vascular diseas...

  18. Cerebral palsy

    International Nuclear Information System (INIS)

    This paper reviews cranial MR findings in patients with cerebral palsy (CP) to clarify and categorize this disorder. The MR images of 40 patients with clinical CP were retrospectively reviewed. All patients suffered either varying spastic plegias, hypotonicity, or choreoathetosis. Concomitantly, the patients suffered from static encephalopathy, developmental delay, and/or microcephaly. Twenty-four patients were born at or near term, 10 were premature, and incomplete birth histories were available in six. The MR images revealed mild to severe degrees of white matter damage in 24 patients (12 term, nine premature, three unknown)

  19. Protein kinase C-dependent increase in reactive oxygen species (ROS) production in vascular tissues of diabetes: role of vascular NAD(P)H oxidase.

    Science.gov (United States)

    Inoguchi, Toyoshi; Sonta, Toshiyo; Tsubouchi, Hirotaka; Etoh, Takashi; Kakimoto, Maiko; Sonoda, Noriyuki; Sato, Naoichi; Sekiguchi, Naotaka; Kobayashi, Kunihisa; Sumimoto, Hideki; Utsumi, Hideo; Nawata, Hajime

    2003-08-01

    Hyperglycemia seems to be an important causative factor in the development of micro- and macrovascular complications in patients with diabetes. Several hypotheses have been proposed to explain the adverse effects of hyperglycemia on vascular cells. Both protein kinase C (PKC) activation and oxidative stress theories have increasingly received attention in recent years. This article shows a PKC-dependent increase in oxidative stress in diabetic vascular tissues. High glucose level stimulated reactive oxygen species (ROS) production via a PKC-dependent activation of NAD(P)H oxidase in cultured aortic endothelial cells, smooth muscle cells, and renal mesangial cells. In addition, expression of NAD(P)H oxidase components were shown to be upregulated in vascular tissues and kidney from animal models of diabetes. Furthermore, several agents that were expected to block the mechanism of a PKC-dependent activation of NAD(P)H oxidase clearly inhibited the increased oxidative stress in diabetic animals, as assessed by in vivo electron spin resonance method. Taken together, these findings strongly suggest that the PKC-dependent activation of NAD(P)H oxidase may be an essential mechanism responsible for increased oxidative stress in diabetes. PMID:12874436

  20. 高压氧治疗促进脑梗死模型大鼠神经再生微环境及神经功能的恢复%Hyperbaric oxygen therapy improves nerve regeneration microenvironment and promotes rat nerve function recovery after cerebral infarction

    Institute of Scientific and Technical Information of China (English)

    孙晶晶; 宋乃光; 张耀龙; 高淑焕; 孙彩悦; 薛建; 贺永贵; 习瑾琨; 张国彬

    2015-01-01

    背景:大量临床研究证实,脊髓损伤区域的微环境通过高压氧可获得显著改善,但高压氧对脑损伤微环境有何影响呢?目的:观察高压氧治疗对大鼠脑梗死区神经再生微环境及神经功能恢复的影响。方法:构建大脑中动脉阻断制作局灶性脑梗死模型大鼠,并进行高压氧治疗,设假手术组和模型组作对照,假手术组不结扎颈内动脉不干预,模型组造模后模拟除压力和氧浓度以外的其他高压氧治疗过程及环境条件。结果与结论:与模型组相比,治疗后第16天高压氧组的大鼠肢体功能评分、术后14 d脑梗死区组织生长相关蛋白43表达均升高(P<0.05),术后24 h梗死灶体积均降低(P <0.05)。结果证实,高压氧治疗促进脑梗死模型大鼠神经再生微环境及神经功能的恢复。%BACKGROUND:Numerous clinical studies have confirmed that the microenvironment at a spinal cord injury site can be obviously improved through hyperbaric oxygen therapy; however, what effect does hyperbaric oxygen have on the microenvironment of the injured brain? OBJECTIVE:To investigate the effect of hyperbaric oxygen therapy on nerve regeneration microenvironment and the recovery of rat nerve function after focal cerebral infarction. METHODS:Rat models of focal cerebral infarction were established by occlusion of the middle cerebral artery and subjected to hyperbaric oxygen therapy. Sham group and model group were established as comparison. In the sham group, rat models of focal cerebral infarction were established but did not receive any treatment. Rats in the model group were placed in a hyperbaric oxygen therapy chamber but the pressure and oxygen concentration were not administered. RESULTS AND CONCLUSION:Compared with the model group, the score of rat limb function at 16 days after treatment and the expression of growth associated protein 43 in the rat cerebral infarcted area at postoperative 14 days were

  1. Human cerebral circulation. Positron emission tomography studies

    International Nuclear Information System (INIS)

    We reviewed the literature on human cerebral circulation and oxygen metabolism, as measured by positron emission tomography (PET), with respect to normal values and of regulation of cerebral circulation. A multicenter study in Japan showed that between-center variations in cerebral blood flow (CBF), cerebral blood volume (CBV), cerebral oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO2) values were not considerably larger than the corresponding within-center variations. Overall mean±SD values in cerebral cortical regions of normal human subjects were as follows: CBF=44.4±6.5 ml/100 ml/min; CBV=3.8±0.7 ml/100 ml; OEF=0.44±0.06; CMRO2=3.3±0.5 ml/100 ml/min (11 PET centers, 70 subjects). Intrinsic regulation of cerebral circulation involves several factors. Autoregulation maintains CBF in response to changes in cerebral perfusion pressure; chemical factors such as PaCO2 affect cerebral vascular tone and alter CBF; changes in neural activity cause changes in cerebral energy metabolism and CBF; neurogenic control of CBF occurs by sympathetic innervation. Regional differences in vascular response to changes in PaCO2 have been reported, indicating regional differences in cerebral vascular tone. Relations between CBF and CBV during changes in PaCO2 and during changes in neural activity were in good agreement with Poiseuille's law. The mechanisms of vascular response to neural activation and deactivation were independent on those of responses to PaCO2 changes. CBV in a brain region is the sum of three components: arterial, capillary and venous blood volumes. It has been reported that the arterial blood volume fraction is approximately 30% in humans and that changes in human CBV during changes in PaCO2 are caused by changes in arterial blood volume without changes in venous blood volume. These findings should be considered in future studies of the pathophysiology of cerebrovascular diseases. (author) 136 refs

  2. Cerebral malaria.

    Science.gov (United States)

    Postels, Douglas G; Birbeck, Gretchen L

    2013-01-01

    Malaria, the most significant parasitic disease of man, kills approximately one million people per year. Half of these deaths occur in those with cerebral malaria (CM). The World Health Organization (WHO) defines CM as an otherwise unexplained coma in a patient with malarial parasitemia. Worldwide, CM occurs primarily in African children and Asian adults, with the vast majority (greater than 90%) of cases occurring in children 5 years old or younger in sub-Saharan Africa. The pathophysiology of the disease is complex and involves infected erythrocyte sequestration, cerebral inflammation, and breakdown of the blood-brain barrier. A recently characterized malarial retinopathy is visual evidence of Plasmodium falciparum's pathophysiological processes occurring in the affected patient. Treatment consists of supportive care and antimalarial administration. Thus far, adjuvant therapies have not been shown to improve mortality rates or neurological outcomes in children with CM. For those who survive CM, residual neurological abnormalities are common. Epilepsy, cognitive impairment, behavioral disorders, and gross neurological deficits which include motor, sensory, and language impairments are frequent sequelae. Primary prevention strategies, including bed nets, vaccine development, and chemoprophylaxis, are in varied states of development and implementation. Continuing efforts to find successful primary prevention options and strategies to decrease neurological sequelae are needed. PMID:23829902

  3. Fatal cerebral arterial gas embolism after endoscopic retrograde cholangiopancreatography

    OpenAIRE

    Rangappa Pradeep; Uhde Britta; Byard Roger; Wurm Alex; Thomas Peter

    2009-01-01

    We report the case of a 50-year-old woman undergoing elective endoscopic retrograde cholangiopancreatography, who developed coma and hemiparesis secondary to severe cerebral artery gas embolism. Despite prompt diagnosis and early hyperbaric oxygen therapy (HBO 2 ) she developed severe cerebral edema and died within 24 h.

  4. Fatal cerebral arterial gas embolism after endoscopic retrograde cholangiopancreatography

    Directory of Open Access Journals (Sweden)

    Rangappa Pradeep

    2009-01-01

    Full Text Available We report the case of a 50-year-old woman undergoing elective endoscopic retrograde cholangiopancreatography, who developed coma and hemiparesis secondary to severe cerebral artery gas embolism. Despite prompt diagnosis and early hyperbaric oxygen therapy (HBO 2 she developed severe cerebral edema and died within 24 h.

  5. 4(α-L-RHAMNOSYLOXY)-BENZYL ISOTHIOCYANATE, A BIOACTIVE PHYTOCHEMICAL THAT DEFENDS CEREBRAL TISSUE AND PREVENTS SEVERE DAMAGE INDUCED BY FOCAL ISCHEMIA/REPERFUSION.

    Science.gov (United States)

    Galuppo, M; Giacoppo, S; Iori, R; De Nicola, G R; Milardi, D; Bramanti, P; Mazzon, E

    2015-01-01

    Natural compounds are a promising source to treat several pathologies. The present study shows the in vivo pharmacological beneficial effect of 4(α-L-rhamnosyloxy)-benzyl isothiocyanate (glucomoringin isothiocyanate; GMG-ITC) obtained from glucomoringin (GMG; 4(α;-L-rhamnosyloxy)- benzyl glucosinolate), purified from Moringa oleifera seeds and hydrolyzed by myrosinase enzyme (β-thioglucoside glucohydrolase; E.C. 3.2.1.147). Cerebral ischemia/reperfusion (CIR) was induced in rats according to a classic model of carotid artery occlusion for a time period of 1 h and the reperfusion time was prolonged for seven days. GMG-ITC (3.5 mg GMG/ml plus 30 μl enzyme/rat; one ml i.p./rat) was administered 15 min after the beginning of ischemia and daily. The results clearly show that GMG-ITC possesses the capability to counteract the CIR-induced damage reducing TNF-alpha release, IκB-alpha cytosolic degradation/NFκBp65 nuclear translocation, as well as several other direct or indirect markers of inflammation (phospho-ERK p42/44, p-selectin) and oxidative stress (inducible Nitric Oxide Synthase (iNOS), MMP-9). GMG-ITC was shown to exert neuroprotective properties in preventing CIR-induced damage and the related cascade of inflammatory and oxidative mediators that exacerbate the progression of this disease in an experimental rat model. Our results clearly show that the tested phytochemical GMG-ITC possesses the capability to counteract CIR-induced damage. PMID:26122222

  6. Investigating cerebral oedema using poroelasticity.

    Science.gov (United States)

    Vardakis, John C; Chou, Dean; Tully, Brett J; Hung, Chang C; Lee, Tsong H; Tsui, Po-Hsiang; Ventikos, Yiannis

    2016-01-01

    Cerebral oedema can be classified as the tangible swelling produced by expansion of the interstitial fluid volume. Hydrocephalus can be succinctly described as the abnormal accumulation of cerebrospinal fluid (CSF) within the brain which ultimately leads to oedema within specific sites of parenchymal tissue. Using hydrocephalus as a test bed, one is able to account for the necessary mechanisms involved in the interaction between oedema formation and cerebral fluid production, transport and drainage. The current state of knowledge about integrative cerebral dynamics and transport phenomena indicates that poroelastic theory may provide a suitable framework to better understand various diseases. In this work, Multiple-Network Poroelastic Theory (MPET) is used to develop a novel spatio-temporal model of fluid regulation and tissue displacement within the various scales of the cerebral environment. The model is applied through two formats, a one-dimensional finite difference - Computational Fluid Dynamics (CFD) coupling framework, as well as a two-dimensional Finite Element Method (FEM) formulation. These are used to investigate the role of endoscopic fourth ventriculostomy in alleviating oedema formation due to fourth ventricle outlet obstruction (1D coupled model) in addition to observing the capability of the FEM template in capturing important characteristics allied to oedema formation, like for instance in the periventricular region (2D model). PMID:26749338

  7. Cerebral hemodynamics in patients with obstructive sleep apnea syndrome monitored with near-infrared spectroscopy (NIRS) during positive airways pressure (CPAP) therapy: a pilot study

    Science.gov (United States)

    Zhang, Zhongxing; Schneider, Maja; Laures, Marco; Fritschi, Ursula; Lehner, Isabella; Qi, Ming; Khatami, Ramin

    2014-03-01

    In obstructive sleep apnea syndrome (OSA) the periodic reduction or cessation of breathing due to narrowing or occlusion of the upper airway during sleep leads to daytime symptoms and increased cardiovascular risk, including stroke. The higher risk of stroke is related to the impairment in cerebral vascular autoregulation. Continuous positive airways pressure (CPAP) therapy at night is the most effective treatment for OSA. However, there is no suitable bedside monitoring method evaluating the treatment efficacy of CPAP therapy, especially to monitor the recovery of cerebral hemodynamics. NIRS is ideally suited for non-invasive monitoring the cerebral hemodynamics during sleep. In this study, we will for first time assess dynamic changes of cerebral hemodynamics during nocturnal CPAP therapy in 3 patients with OSA using NIRS. We found periodic oscillations in HbO2, HHb, tissue oxygenation index (TOI) and blood volume associated with periodic apnea events without CPAP in all OSA patients. These oscillations were gradually attenuated and finally eliminated with the stepwise increments of CPAP pressures. The oscillations were totally eliminated in blood volume earlier than in other hemodynamic parameters. These results suggested that 1) the cerebral hemodynamic oscillations induced by OSA events can effectively be attenuated by CPAP therapy, and 2) blood flow and blood volume recovered first during CPAP therapy, followed by the recovery of oxygen consumption. Our study suggested that NIRS is a useful tool to evaluate the efficacy of CPAP therapy in patients with OSA bedside and in real time.

  8. Alteration of Brain Oxygenation During "Piggy Back" Liver Transplantation

    Science.gov (United States)

    Panzera, Piercarmine; Greco, Luigi; Carravetta, Giuseppe; Gentile, Antonella; Catalano, Giorgio; Cicco, Giuseppe; Memeo, Vincenzo

    Relevant changes in cerebral circulation occur during "Piggy Back" liver transplantation. Particularly at the washout-reperfusion time the cerebral perfusion suddenly changes from its lowest to its highest values. Further investigation is required to evaluate whether patients with the greatest change in cerebral oxygenation at this time point will suffer neurological complications after transplantation.

  9. Hemodynamic and metabolic effects of cerebral revascularization.

    Science.gov (United States)

    Leblanc, R; Tyler, J L; Mohr, G; Meyer, E; Diksic, M; Yamamoto, L; Taylor, L; Gauthier, S; Hakim, A

    1987-04-01

    Pre- and postoperative positron emission tomography (PET) was performed in six patients undergoing extracranial to intracranial bypass procedures for the treatment of symptomatic extracranial carotid occlusion. The six patients were all men, aged 52 to 68 years. Their symptoms included transient ischemic attacks (five cases), amaurosis fugax (two cases), and completed stroke with good recovery (one case). Positron emission tomography was performed within 4 weeks prior to surgery and between 3 to 6 months postoperatively, using oxygen-15-labeled CO, O2, and CO2 and fluorine-18-labeled fluorodeoxyglucose. Cerebral blood flow (CBF), cerebral blood volume (CBV), cerebral metabolic rates for oxygen and glucose (CMRO2 and CMRGlu), and the oxygen extraction fraction (OEF) were measured in both hemispheres. Preoperatively, compared to five elderly control subjects, patients had increased CBV, a decreased CBF/CBV ratio, and decreased CMRO2, indicating reduced cerebral perfusion pressure and depressed oxygen metabolism. The CBF was decreased in only one patient who had bilateral carotid occlusions; the OEF, CMRGlu, and CMRO2/CMRGlu and CMRGlu/CBF ratios were not significantly different from control measurements. All bypasses were patent and all patients were asymptomatic following surgery. Postoperative PET revealed decreased CBV and an increased CBF/CBV ratio, indicating improved hemodynamic function and oxygen hypometabolism. This was associated with increased CMRO2 in two patients in whom the postoperative OEF was also increased. The CMRGlu and CMRGlu/CBF ratio were increased in five patients. Changes in CBF and the CMRO2/CMRGlu ratio were variable. One patient with preoperative progressive mental deterioration, documented by serial neuropsychological testing and decreasing CBF and CMRO2, had improved postoperative CBF and CMRO2 concomitant with improved neuropsychological functioning. It is concluded that symptomatic carotid occlusion is associated with altered

  10. Cerebral energy metabolism during mitochondrial dysfunction induced by cyanide in piglets

    DEFF Research Database (Denmark)

    Nielsen, Troels Halfeld; Olsen, N.V.; Toft, P; Nordström, C H

    2013-01-01

    variables related to energy metabolism. METHODS: Mitochondrial dysfunction was induced in piglets and evaluated by monitoring brain tissue oxygen tension (PbtO2 ) and cerebral levels of glucose, lactate, pyruvate, glutamate, and glycerol bilaterally. The biochemical variables were obtained by microdialysis...... insufficient energy metabolism and degradation of cellular membranes, respectively. CONCLUSION: Mitochondrial dysfunction is characterised by an increased LP ratio signifying a shift in cytoplasmatic redox state at normal or elevated PbtO2 . The condition is biochemically characterised by a marked increase in...

  11. Ultrasound tagged near infrared spectroscopy does not detect hyperventilation-induced reduction in cerebral blood flow

    DEFF Research Database (Denmark)

    Lund, Anton; Secher, Niels H; Hirasawa, Ai;

    2015-01-01

    healthy males (age 21-26 years) hyperventilated and were administered phenylephrine to increase mean arterial pressure by 20-30 mmHg. Frontal lobe tissue oxygenation (ScO2) and CFI were obtained using the CerOx and mean blood flow velocity in the middle cerebral artery (MCAvmean) was determined by....... Administration of phenylephrine was not associated with any changes in MCAvmean, ICAf, ECAf, ScO2, SkBF, SskinO2, or CFI. CONCLUSION: The CerOx was able to detect a stable CBF during administration of phenylephrine. However, during hyperventilation MCAvmean and ICAf decreased while CFI increased, likely due to...

  12. Cerebral autoregulation in the preterm newborn using near-infrared spectroscopy

    DEFF Research Database (Denmark)

    Eriksen, Vibeke R; Holst Hahn, Gitte; Greisen, Gorm

    2015-01-01

    The aim was to compare two conventional methods used to describe cerebral autoregulation (CA): frequency-domain analysis and time-domain analysis. We measured cerebral oxygenation (as a surrogate for cerebral blood flow) and mean arterial blood pressure (MAP) in 60 preterm infants. In the frequen...