WorldWideScience

Sample records for cerebral oxygen metabolism

  1. 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).

  2. 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...... with a lower plasma epinephrine concentration (P exercising at 70% of maximal oxygen uptake (approximately 211 W). Before training, both OCI (3.9 +/- 0.9) and DeltaP(Mito)O(2) (-22 mmHg) decreased (P ... attenuates the cerebral metabolic response to submaximal exercise, as reflected in a lower carbohydrate uptake and maintained cerebral oxygenation....

  3. Influence of remote ischemic preconditioning on cerebral oxygen metabolism and cerebral blood flow indexes of patients with ischemic cerebrovascular disease

    Institute of Scientific and Technical Information of China (English)

    Hui Lu; Ning-Ning Cui; Bin-Cheng Wang

    2016-01-01

    Objective:To study the influence of remote ischemic preconditioning on cerebral oxygen metabolism and cerebral blood flow indexes of patients with ischemic cerebrovascular disease. Methods:A total of 58 patients with ischemic cerebrovascular disease in our hospital from April 2015 to January 2016 were selected as the study object, and 58 patients were randomly divided into two groups, 29 patients in control group were treated with routine treatment, 29 patients in observation group were treated with remote ischemic preconditioning on the basic treatment of control group, then the cerebral oxygen metabolism and cerebral blood flow indexes of two groups before the treatment and at first, third and sixth month after the treatment were respectively detected and compared.Results:The cerebral oxygen metabolism and cerebral blood flow indexes of two groups before the treatment all showed no significant differences (allP>0.05), while the cerebral oxygen metabolism and cerebral blood flow indexes of observation group at first, third and sixth month after the treatment were all significantly better than those before the treatment, and the results were all significantly better than those of control group at the same time too (allP>0.05).Conclusions: The influence of remote ischemic preconditioning on cerebral oxygen metabolism and cerebral blood flow indexes of patients with ischemic cerebrovascular disease are better, and its application value for the patients with ischemic cerebrovascular disease is higher.

  4. Correlation between cerebral oxygen metabolism and cerebral blood flow simultaneously measured before and after acetazolamide administration

    Science.gov (United States)

    Yamaguchi, Hiroichiro; Yamauchi, Hideto; Hazama, Shiro; Hamamoto, Hirotsugu; Inoue, Nobuhiro

    1999-10-01

    The cerebral circulation and metabolism of ten preoperative cardiac surgery patients were assessed. Alterations in regional cerebral blood flow (rCBF), measured by 123I-N- isopropyl-p-iodo-amphetamine single-photon emission computed tomography, and in cerebral oxygen metabolism, simultaneously detected by near-infrared spectroscopy (NIRS) before and after acetazolamide administration, were investigated. The rCBF (ml/min/100 g) increased significantly from 40.21 +/- 7.65 to 56.24 +/- 13.69 (p equals 0.001), and a significant increase in oxyhemoglobin (Oxy-Hb) of 13.9% (p equals 0.0022) and total hemoglobin (Total-Hb) of 5.7% (0.0047) along with a significant decrease in deoxyhemoglobin (Deoxy-Hb) of 8.9% (p equals 0.0414) were observed concomitantly. Thus, the Oxy-Hb/Total- Hb ratio (%Oxy-Hb) rose significantly from 67.26 +/- 9.82% to 72.98 +/- 8.09% (p equals 0.0022). Examination of the relationships between individual parameters showed that the percentage changes in rCBF and Oxy-Hb were significantly correlated (r equals 0.758, p equals 0.011). The percentage changes in rCBF and %Oxy-Hb were also correlated significantly (r equals 0.740, p equals 0.014). In conclusion, this evidence suggested that NIRS is able to detect relative changes in cerebral hemodynamics and reflect luxury perfusion induced by acetazolamide.

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

    DEFF Research Database (Denmark)

    Borghammer, Per; Cumming, Paul; Østergaard, Karen;

    2012-01-01

    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...

  6. PET imaging of cerebral perfusion and oxygen metabolism in stroke

    Energy Technology Data Exchange (ETDEWEB)

    Pointon, O.; Yasaka, M.; Berlangieri, S.U.; Newton, M.R.; Thomas, D.L.; Chan, C.G.; Egan, G.F.; Tochon-Danguy, H.J.; O``Keefe, G.; Donnan, G.A.; McKay, W.J. [Austin Hospital, Melbourne, VIC (Australia). Centre for PET and Depts of Nuclear Medicine and Neurology

    1998-03-01

    Full text: Stroke remains a devastating clinical event with few therapeutic options. In patients with acute stroke, we studied the cerebral perfusion and metabolic patterns with {sup 15}O-CO{sub 2} or H{sub 2}O and {sup 15}O-O{sub 2} positron emission tomography and correlated these findings to the clinical background. Forty three patients underwent 45 studies 0-23 days post-stroke (mean 7 days). Fifteen patients showed luxury perfusion (Group A), 10 had matched low perfusion and metabolism (B) and 3 showed mixed pattern including an area of misery perfusion (C). Seventeen showed no relevant abnormality (D) and there were no examples of isolated misery perfusion. Twelve of the 15 in Group A had either haemorrhagic transformation on CT, re-opening on angiography, or a cardioembolic mechanism. In contrast only 5/10 in Group B, 0/3 in Group C and 2/17 in Group D had these features. Although 7/10 in group B had moderate or large size infarcts on CT the incidence of haemorrhagic transformation was low (2/10) and significant carotid stenoses were more common in those studied (5/8) compared with the other groups. Misery perfusion was not seen beyond five days. Thus, luxury perfusion seems to be related to a cardio-embolic mechanism or reperfusion. Matched low perfusion and metabolism was associated with a low rate of haemorrhagic transformation despite a high incidence of moderate to large size infarcts. Misery perfusion is an early phenomenon in the evolution of ischaemic stroke.

  7. 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).

  8. 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

    Studies have shown decreased cerebral oxygen metabolism (CMRO(2)) and blood flow (CBF) in patients with cirrhosis with hepatic encephalopathy (HE). It remains unclear, however, whether these disturbances are associated with HE or with cirrhosis itself and how they may relate to arterial blood...... ammonia concentration and cerebral metabolic rate of blood ammonia (CMRA). We addressed these questions in a paired study design by investigating patients with cirrhosis during and after recovery from an acute episode of HE type C. CMRO(2), CBF, and CMRA were measured by dynamic positron emission...

  9. 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......)), glucose and lactate across the brain. The molar ratio between the cerebral uptake of O(2) versus carbohydrate (O(2)-carbohydrate index; O(2) / [glucose + 0.5 lactate]; OCI), the cerebral metabolic rate of O(2) (CMRO(2)) and changes in mitochondrial O(2) tension (P(mito)O(2)) were calculated. W...

  10. The cerebral metabolic ratio is not affected by oxygen availability during maximal exercise in humans

    DEFF Research Database (Denmark)

    Volianitis, S.; Fabricius-Bjerre, A.; Overgaard, A.;

    2008-01-01

    .2% during exercise with an inspired O(2) fraction of 0.17 and 0.30, respectively. Whilst the increase in a-v lactate difference was attenuated by manipulation of cerebral O(2) availability, the cerebral metabolic ratio was not affected significantly. During maximal rowing, the cerebral metabolic ratio...

  11. 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)

  12. Time-dependent changes in cerebral blood flow after acetazolamide loading into patients with hemodynamic cerebral ischemia. Relationship to cerebral oxygen metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Masakazu [Iwate Medical Univ., Morioka (Japan). School of Medicine

    2001-10-01

    The aim of this study was to clarify the relationship between time-dependent changes in cerebral blood flow (CBF) after acetazolamide loading and cerebral oxygen metabolism (CMRO{sub 2}). The subjects consisted of 30 patients with severe stenosis or occlusion of either internal carotid, middle cerebral, or vertebro-basilar artery. Regional CBF was measured at the resting state and 6, 16 and 30 minutes after intravenous administration of 1 gram of acetazolamide using the positron emission tomography in combination with the [{sup 15}O] H{sub 2}O bolus-injection method. Prior to CBF study, regional cerebral oxygen extraction fraction (OEF) was measured using the [{sup 15}O] O{sub 2} inhalation method. Regional CMRO{sub 2} was calculated based on CBF and OEF. According to the time-dependent changes in CBF responses to acetazolamide loading, the CBF responses are classified into good response type, paradoxical response type, and poor response type. Good response type (CBF increase rate more than 20% 6 minutes after acetazolamide loading), paradoxical response type (decrease of CBF 6 minutes after acetazolamide loading) and poor response type (CBF increase rate less than 20% 6 minutes after acetazolamide loading) were identified in 39, 11 and 10 areas, respectively. Brain areas with good response type showed normal OEF and normal CMRO{sub 2}. Brain areas with paradoxical response type showed increased OEF and normal CMRO{sub 2}. Brain areas with poor response type showed normal OEF and decreased CMRO{sub 2}. In view of these findings, the writer concludes that sequential measurement of cerebral blood flow (CBF) after acetazolamide loading enables one to know the regional cerebral oxygen metabolic state in patients with hemodynamic ischemia, and CBF should be measured at an early stage after the administration of acetazolamide to accurately detect misery perfusion. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Herold, S.

    1985-03-01

    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.

  14. Effects of aging on cerebral blood flow, oxygen metabolism, and blood oxygenation level dependent responses to visual stimulation.

    Science.gov (United States)

    Ances, Beau M; Liang, Christine L; Leontiev, Oleg; Perthen, Joanna E; Fleisher, Adam S; Lansing, Amy E; Buxton, Richard B

    2009-04-01

    Calibrated functional magnetic resonance imaging (fMRI) provides a noninvasive technique to assess functional metabolic changes associated with normal aging. We simultaneously measured both the magnitude of the blood oxygenation level dependent (BOLD) and cerebral blood flow (CBF) responses in the visual cortex for separate conditions of mild hypercapnia (5% CO(2)) and a simple checkerboard stimulus in healthy younger (n = 10, mean: 28-years-old) and older (n = 10, mean: 53-years-old) adults. From these data we derived baseline CBF, the BOLD scaling parameter M, the fractional change in the cerebral metabolic rate of oxygen consumption (CMRO(2)) with activation, and the coupling ratio n of the fractional changes in CBF and CMRO(2). For the functional activation paradigm, the magnitude of the BOLD response was significantly lower for the older group (0.57 +/- 0.07%) compared to the younger group (0.95 +/- 0.14%), despite the finding that the fractional CBF and CMRO(2) changes were similar for both groups. The weaker BOLD response for the older group was due to a reduction in the parameter M, which was significantly lower for older (4.6 +/- 0.4%) than younger subjects (6.5 +/- 0.8%), most likely reflecting a reduction in baseline CBF for older (41.7 +/- 4.8 mL/100 mL/min) compared to younger (59.6 +/- 9.1 mL/100 mL/min) subjects. In addition to these primary responses, for both groups the BOLD response exhibited a post-stimulus undershoot with no significant difference in this magnitude. However, the post-undershoot period of the CBF response was significantly greater for older compared to younger subjects. We conclude that when comparing two populations, the BOLD response can provide misleading reflections of underlying physiological changes. A calibrated approach provides a more quantitative reflection of underlying metabolic changes than the BOLD response alone.

  15. Optical measurement of cerebral hemodynamics and oxygen metabolism in neonates with congenital heart defects

    Science.gov (United States)

    Durduran, Turgut; Zhou, Chao; Buckley, Erin M.; Kim, Meeri N.; Yu, Guoqiang; Choe, Regine; Gaynor, J. William; Spray, Thomas L.; Durning, Suzanne M.; Mason, Stefanie E.; Montenegro, Lisa M.; Nicolson, Susan C.; Zimmerman, Robert A.; Putt, Mary E.; Wang, Jiongjiong; Greenberg, Joel H.; Detre, John A.; Yodh, Arjun G.; Licht, Daniel J.

    2010-05-01

    We employ a hybrid diffuse correlation spectroscopy (DCS) and near-infrared spectroscopy (NIRS) monitor for neonates with congenital heart disease (n=33). The NIRS-DCS device measured changes during hypercapnia of oxyhemoglobin, deoxyhemoglobin, and total hemoglobin concentrations; cerebral blood flow (rCBFDCS); and oxygen metabolism (rCMRO2). Concurrent measurements with arterial spin-labeled magnetic resonance imaging (rCBFASL-MRI, n=12) cross-validate rCBFDCS against rCBFASL-MRI, showing good agreement (R=0.7, p=0.01). The study demonstrates use of NIRS-DCS on a critically ill neonatal population, and the results indicate that the optical technology is a promising clinical method for monitoring this population.

  16. 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

  17. Quantifying the cerebral metabolic rate of oxygen by combining diffuse correlation spectroscopy and time-resolved near-infrared spectroscopy.

    Science.gov (United States)

    Verdecchia, Kyle; Diop, Mamadou; Lee, Ting-Yim; St Lawrence, Keith

    2013-02-01

    Preterm infants are highly susceptible to ischemic brain injury; consequently, continuous bedside monitoring to detect ischemia before irreversible damage occurs would improve patient outcome. In addition to monitoring cerebral blood flow (CBF), assessing the cerebral metabolic rate of oxygen (CMRO2) would be beneficial considering that metabolic thresholds can be used to evaluate tissue viability. The purpose of this study was to demonstrate that changes in absolute CMRO2 could be measured by combining diffuse correlation spectroscopy (DCS) with time-resolved near-infrared spectroscopy (TR-NIRS). Absolute CBF was determined using bolus-tracking TR-NIRS to calibrate the DCS measurements. Cerebral venous blood oxygenation (SvO2) was determined by multiwavelength TR-NIRS measurements, the accuracy of which was assessed by directly measuring the oxygenation of sagittal sinus blood. In eight newborn piglets, CMRO2 was manipulated by varying the anesthetics and by injecting sodium cyanide. No significant differences were found between the two sets of SvO2 measurements obtained by TR-NIRS or sagittal sinus blood samples and the corresponding CMRO2 measurements. Bland-Altman analysis showed a mean CMRO2 difference of 0.0268 ± 0.8340 mLO2/100 g/min between the two techniques over a range from 0.3 to 4 mL O2/100 g/min.

  18. 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.

  19. 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.

  20. 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.

  1. Effect of sevoflurane and propofol on cerebral oxygen metabolism in cardiopulmonary bypass and postoperative neurological function injury

    Institute of Scientific and Technical Information of China (English)

    Zhu Zhu; Wei-Wei Li

    2016-01-01

    Objective:To study the effect of sevoflurane and propofol on cerebral oxygen metabolism in cardiopulmonary bypass (CPB) and postoperative neurological function injury.Methods:A total of 48 cases of patients who received mitral valve replacement under CPB in our hospital were selected and randomly divided into sevoflurane group (S group) and propofol group (P group) who received sevoflurane-based intravenous inhalational anesthesia and propofol-based total intravenous anesthesia respectively, cerebral oxygen metabolism indexes were determined before CPB started (T0), when nasopharyngeal temperature fell to a constant low temperature (T1), when CPB ended (T2) and 1 h after CPB ended (T3) respectively during operation, and serum neurological function, cardiac function and liver function injury molecules were determined after operation.Results: Intraoperative SjvO2, AVDO2, O2ER and rSO2 were not significantly different between two groups, SjvO2 at T1 significantly increased, AVDO2 and O2ER significantly decreased and rSO2 didn’t change significantly, SjvO2 at T2 significantly decreased, AVDO2 and O2ER significantly increased and rSO2 didn’t change significantly; postoperative serum NSE, S100β, Aβ, Glu, Asp and Gly levels of S group were significantly lower than those of P group, and CK-MB, LDH, cTnI, ALT and AST levels were not significantly different from those of P group.Conclusion:Both sevoflurane and propofol can maintain the balance of cerebral oxygen metabolism in mitral valve replacement under CPB and protect the cardiac function and liver function, but sevoflurane has more ideal protective effect on postoperative neurological function.

  2. Cerebral oxygenation and hyperthermia

    Directory of Open Access Journals (Sweden)

    Anthony Richard Bain

    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.

  3. 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...... 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....

  4. Database of normal human cerebral blood flow, cerebral blood volume, cerebral oxygen extraction fraction and cerebral metabolic rate of oxygen measured by positron emission tomography with {sup 15}O-labelled carbon dioxide or water, carbon monoxide and oxygen: a multicentre study in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Hiroshi [Department of Radiology and Nuclear Medicine, Akita Research Institute of Brain and Blood Vessels, Akita (Japan); Department of Nuclear Medicine and Radiology, Division of Brain Sciences, Institute of Development, Aging and Cancer, Tohoku University, 4-1 Seiryo-Machi, 980-8575, Aoba-Ku, Sendai (Japan); Kanno, Iwao [Department of Radiology and Nuclear Medicine, Akita Research Institute of Brain and Blood Vessels, Akita (Japan); Kato, Chietsugu [Department of Nuclear Medicine, Hokkaido University School of Medicine, Sapporo (Japan); Sasaki, Toshiaki [Cyclotoron Research Center, Iwate Medical University, Morioka (Japan); Ishii, Kenji [Positron Medical Center, Tokyo Metropolitan Institute of Gerontology, Tokyo (Japan); Ouchi, Yasuomi [Positron Medical Center, Hamamatsu Medical Center, Hamakita (Japan); Iida, Akihiko [Nagoya City Rehabilitation Center, Nagoya (Japan); Okazawa, Hidehiko [PET Unit, Research Institute, Shiga Medical Center, Moriyama (Japan); Hayashida, Kohei [Department of Radiology, National Cardiovascular Center, Suita, Osaka (Japan); Tsuyuguchi, Naohiro [Department of Neurosurgery, Osaka City University Medical School, Osaka (Japan); Ishii, Kazunari [Division of Imaging Research, Hyogo Institute for Aging Brain and Cognitive Disorders, Himeji, Hyogo (Japan); Kuwabara, Yasuo [Department of Radiology, Faculty of Medicine, Kyushu University, Fukuoka (Japan); Senda, Michio [Department of Image-based Medicine, Institute of Biomedical Research and Innovation, Kobe (Japan)

    2004-05-01

    Measurement of cerebral blood flow (CBF), cerebral blood volume (CBV), cerebral oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO{sub 2}) by positron emission tomography (PET) with oxygen-15 labelled carbon dioxide (C{sup 15}O{sub 2}) or {sup 15}O-labelled water (H{sub 2}{sup 15}O), {sup 15}O-labelled carbon monoxide (C{sup 15}O) and {sup 15}O-labelled oxygen ({sup 15}O{sub 2}) is useful for diagnosis and treatment planning in cases of cerebrovascular disease. The measured values theoretically depend on various factors, which may differ between PET centres. This study explored the applicability of a database of {sup 15}O-PET by examining between-centre and within-centre variation in values. Eleven PET centres participated in this multicentre study; seven used the steady-state inhalation method, one used build-up inhalation and three used bolus administration of C{sup 15}O{sub 2} (or H{sub 2}{sup 15}O) and {sup 15}O{sub 2}. All used C{sup 15}O for measurement of CBV. Subjects comprised 70 healthy volunteers (43 men and 27 women; mean age 51.8{+-}15.1 years). Overall mean{+-}SD values for cerebral cortical regions were: CBF=44.4{+-}6.5 ml 100 ml{sup -1} min{sup -1}; CBV=3.8{+-}0.7 ml 100 ml{sup -1}; OEF=0.44{+-}0.06; CMRO{sub 2}=3.3{+-}0.5 ml 100 ml{sup -1} min{sup -1}. Significant between-centre variation was observed in CBV, OEF and CMRO{sub 2} by one-way analysis of variance. However, the overall inter-individual variation in CBF, CBV, OEF and CMRO{sub 2} was acceptably small. Building a database of normal cerebral haemodynamics obtained by the{sup 15}O-PET methods may be practicable. (orig.)

  5. In vivo imaging of hemodynamics and oxygen metabolism in acute focal cerebral ischemic rats with laser speckle imaging and functional photoacoustic microscopy

    Science.gov (United States)

    Deng, Zilin; Wang, Zhen; Yang, Xiaoquan; Luo, Qingming; Gong, Hui

    2012-08-01

    Stroke is a devastating disease. The changes in cerebral hemodynamics and oxygen metabolism associated with stroke play an important role in pathophysiology study. But the changes were difficult to describe with a single imaging modality. Here the changes in cerebral blood flow (CBF), cerebral blood volume (CBV), and oxygen saturation (SO2) were yielded with laser speckle imaging (LSI) and photoacoustic microscopy (PAM) during and after 3-h acute focal ischemic rats. These hemodynamic measures were further synthesized to deduce the changes in oxygen extraction fraction (OEF). The results indicate that all the hemodynamics except CBV had rapid declines within 40-min occlusion of middle cerebral artery (MCAO). CBV in arteries and veins first increased to the maximum value of 112.42±36.69% and 130.58±31.01% by 15 min MCAO; then all the hemodynamics had a persistent reduction with small fluctuations during the ischemic. When ischemia lasted for 3 h, CBF in arteries, veins decreased to 17±14.65%, 24.52±20.66%, respectively, CBV dropped to 62±18.56% and 59±18.48%. And the absolute SO2 decreased by 40.52±22.42% and 54.24±11.77%. After 180-min MCAO, the changes in hemodynamics and oxygen metabolism were also quantified. The study suggested that combining LSI and PAM provides an attractive approach for stroke detection in small animal studies.

  6. 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.)

  7. 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.)

  8. Monitoring Cerebral Oxygenation in Neonates: An Update

    Science.gov (United States)

    Dix, Laura Marie Louise; van Bel, Frank; Lemmers, Petra Maria Anna

    2017-01-01

    Cerebral oxygenation is not always reflected by systemic arterial oxygenation. Therefore, regional cerebral oxygen saturation (rScO2) monitoring with near-infrared spectroscopy (NIRS) is of added value in neonatal intensive care. rScO2 represents oxygen supply to the brain, while cerebral fractional tissue oxygen extraction, which is the ratio between rScO2 and systemic arterial oxygen saturation, reflects cerebral oxygen utilization. The balance between oxygen supply and utilization provides insight in neonatal cerebral (patho-)physiology. This review highlights the potential and limitations of cerebral oxygenation monitoring with NIRS in the neonatal intensive care unit. PMID:28352624

  9. Combined administration of hyperbaric oxygen and hydroxocobalamin improves cerebral metabolism after acute cyanide poisoning in rats

    DEFF Research Database (Denmark)

    Hansen, M B; Olsen, Niels Vidiendal; Hyldegaard, O

    2013-01-01

    Hyperbaric oxygen therapy (HBOT) or intravenous hydroxocobalamin (OHCob) both abolish cyanide (CN)-induced surges in interstitial brain lactate and glucose concentrations. HBOT has been shown to induce a delayed increase in whole blood CN concentrations, whereas OHCob may act as an intravascular CN...

  10. A novel method of combining blood oxygenation and blood flow sensitive magnetic resonance imaging techniques to measure the cerebral blood flow and oxygen metabolism responses to an unknown neural stimulus.

    Directory of Open Access Journals (Sweden)

    Aaron B Simon

    Full Text Available Simultaneous implementation of magnetic resonance imaging methods for Arterial Spin Labeling (ASL and Blood Oxygenation Level Dependent (BOLD imaging makes it possible to quantitatively measure the changes in cerebral blood flow (CBF and cerebral oxygen metabolism (CMRO(2 that occur in response to neural stimuli. To date, however, the range of neural stimuli amenable to quantitative analysis is limited to those that may be presented in a simple block or event related design such that measurements may be repeated and averaged to improve precision. Here we examined the feasibility of using the relationship between cerebral blood flow and the BOLD signal to improve dynamic estimates of blood flow fluctuations as well as to estimate metabolic-hemodynamic coupling under conditions where a stimulus pattern is unknown. We found that by combining the information contained in simultaneously acquired BOLD and ASL signals through a method we term BOLD Constrained Perfusion (BCP estimation, we could significantly improve the precision of our estimates of the hemodynamic response to a visual stimulus and, under the conditions of a calibrated BOLD experiment, accurately determine the ratio of the oxygen metabolic response to the hemodynamic response. Importantly we were able to accomplish this without utilizing a priori knowledge of the temporal nature of the neural stimulus, suggesting that BOLD Constrained Perfusion estimation may make it feasible to quantitatively study the cerebral metabolic and hemodynamic responses to more natural stimuli that cannot be easily repeated or averaged.

  11. A novel method of combining blood oxygenation and blood flow sensitive magnetic resonance imaging techniques to measure the cerebral blood flow and oxygen metabolism responses to an unknown neural stimulus.

    Science.gov (United States)

    Simon, Aaron B; Griffeth, Valerie E M; Wong, Eric C; Buxton, Richard B

    2013-01-01

    Simultaneous implementation of magnetic resonance imaging methods for Arterial Spin Labeling (ASL) and Blood Oxygenation Level Dependent (BOLD) imaging makes it possible to quantitatively measure the changes in cerebral blood flow (CBF) and cerebral oxygen metabolism (CMRO(2)) that occur in response to neural stimuli. To date, however, the range of neural stimuli amenable to quantitative analysis is limited to those that may be presented in a simple block or event related design such that measurements may be repeated and averaged to improve precision. Here we examined the feasibility of using the relationship between cerebral blood flow and the BOLD signal to improve dynamic estimates of blood flow fluctuations as well as to estimate metabolic-hemodynamic coupling under conditions where a stimulus pattern is unknown. We found that by combining the information contained in simultaneously acquired BOLD and ASL signals through a method we term BOLD Constrained Perfusion (BCP) estimation, we could significantly improve the precision of our estimates of the hemodynamic response to a visual stimulus and, under the conditions of a calibrated BOLD experiment, accurately determine the ratio of the oxygen metabolic response to the hemodynamic response. Importantly we were able to accomplish this without utilizing a priori knowledge of the temporal nature of the neural stimulus, suggesting that BOLD Constrained Perfusion estimation may make it feasible to quantitatively study the cerebral metabolic and hemodynamic responses to more natural stimuli that cannot be easily repeated or averaged.

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

    Energy Technology Data Exchange (ETDEWEB)

    Yamauchi, Hiroshi; Okazawa, Hidehiko; Kishibe, Yoshihiko; Sugimoto, Kanji; Takahashi, Masaaki [Research Institute, Shiga Medical Center, 5-4-30 Moriyama, Moriyama-city, Shiga 524-8524 (Japan)

    2002-10-01

    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 (CMRO{sub 2}) 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 CMRO{sub 2} 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 CMRO{sub 2} at baseline with respect to the percent change in CBF during acetazolamide administration. Both increased CBV and decreased CMRO{sub 2} 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 CMRO{sub 2} accounted for 19% and 4% of the variance, respectively. In patients with major cerebral arterial occlusive disease, a decrease in CMRO{sub 2} may contribute to the reduced CBF response to acetazolamide, although an increase in CBV appears to be the major contributing factor. (orig.)

  13. Cerebral blood flow and oxygen metabolism in patients with dementia of the Alzheimer's type by position emission tomography using 0-15 steady state technique

    Energy Technology Data Exchange (ETDEWEB)

    Sakamoto, Shizuki; Kitamura, Shin; Ujike, Takashi; Terashi, Akiro; Iio, Masaaki.

    1988-07-01

    In 12 patients with dementia of the Alzheimer's type (DAT) and 5 age-matched healthy subjects, regional cerebral blood flow (rCBF), oxygen extraction fraction (rOEF), and cerebral oxygen consumption (rCMRO/sub 2/) were determined using positron emission tomography (PET) with 0-15 labeled CO/sub 2/ and O/sub 2/ inhalation method. There was a significant reduction in CMRO/sub 2/ of the temporal cortex in the group of mild DAT compared with the control group. In the group of moderate DAT, CBF of the temporal cortex and CMRO/sub 2/ of the temporal and parietal cortices were significantly reduced. The group of severe DAT showed a significantly reduced CBF and CMRO/sub 2/ in the frontal cortex, and a relatively spared occipital cortex in all stages. The results indicated that metabolic reduction in the temporal cortex first occurs, and that metabolic dysfunction in the parietal and frontal cortices results in blood flow reduction and deterioration of DAT. Right/left metabolic asymmetry in the temporal and parietal cortices was correlated with language and visuospatial functions. (Namekawa, K).

  14. Regional differences in the coupling of cerebral blood flow and oxygen metabolism changes in response to activation: implications for BOLD-fMRI.

    Science.gov (United States)

    Ances, Beau M; Leontiev, Oleg; Perthen, Joanna E; Liang, Christine; Lansing, Amy E; Buxton, Richard B

    2008-02-15

    Functional magnetic resonance imaging (fMRI) based on blood oxygenation level dependent (BOLD) signal changes is a sensitive tool for mapping brain activation, but quantitative interpretation of the BOLD response is problematic. The BOLD response is primarily driven by cerebral blood flow (CBF) changes, but is moderated by M, a scaling parameter reflecting baseline deoxyhemoglobin, and n, the ratio of fractional changes in CBF to cerebral metabolic rate of oxygen consumption (CMRO(2)). We compared M and n between cortical (visual cortex, VC) and subcortical (lentiform nuclei, LN) regions using a quantitative approach based on calibrating the BOLD response with a hypercapnia experiment. Although M was similar in both regions (~5.8%), differences in n (2.21+/-0.03 in VC and 1.58+/-0.03 in LN; Cohen d=1.71) produced substantially weaker (~3.7x) subcortical than cortical BOLD responses relative to CMRO(2) changes. Because of this strong sensitivity to n, BOLD response amplitudes cannot be interpreted as a quantitative reflection of underlying metabolic changes, particularly when comparing cortical and subcortical regions.

  15. Improved light collection and wavelet de-noising enable quantification of cerebral blood flow and oxygen metabolism by a low-cost, off-the-shelf spectrometer

    Science.gov (United States)

    Diop, Mamadou; Wright, Eric; Toronov, Vladislav; Lee, Ting-Yim; St. Lawrence, Keith

    2014-05-01

    Broadband continuous-wave near-infrared spectroscopy (CW-NIRS) is an attractive alternative to time-resolved and frequency-domain techniques for quantifying cerebral blood flow (CBF) and oxygen metabolism in newborns. However, efficient light collection is critical to broadband CW-NIRS since only a small fraction of the injected light emerges from any given area of the scalp. Light collection is typically improved by optimizing the contact area between the detection system and the skin by means of light guides with large detection surface. Since the form-factor of these light guides do not match the entrance of commercial spectrometers, which are usually equipped with a narrow slit to improve their spectral resolution, broadband NIRS spectrometers are typically custom-built. Nonetheless, off-the-shelf spectrometers have attractive advantages compared to custom-made units, such as low cost, small footprint, and wide availability. We demonstrate that off-the-shelf spectrometers can be easily converted into suitable instruments for deep tissue spectroscopy by improving light collection, while maintaining good spectral resolution, and reducing measurement noise. The ability of this approach to provide reliable cerebral hemodynamics was illustrated in a piglet by measuring CBF and oxygen metabolism under different anesthetic regimens.

  16. Feasibility of mapping the tissue mass corrected bioscale of cerebral metabolic rate of oxygen consumption using 17-oxygen and 23-sodium MR imaging in a human brain at 9.4 T.

    Science.gov (United States)

    Atkinson, Ian C; Thulborn, Keith R

    2010-06-01

    The reduction of molecular oxygen to water is the final step of oxidative phosphorylation that couples adenosine triphosphate production to the reoxidation of reducing equivalents formed during the oxidation of glucose to carbon dioxide. This coupling makes the cerebral metabolic rate of oxygen consumption (CMRO(2)) an excellent reflection of the metabolic health of the brain. A multi-nuclear magnetic resonance (MR) imaging based method for CMRO(2) mapping is proposed. Oxygen consumption is determined by applying a new three-phase metabolic model for water generation and clearance to the changing 17-oxygen ((17)O) labeled water MR signal measured using quantitative (17)O MR imaging during inhalation of (17)O-enriched oxygen gas. These CMRO(2) data are corrected for the regional brain tissue mass computed from quantitative 23-sodium MR imaging of endogenous tissue sodium ions to derive quantitative results of oxygen consumption in micromoles O(2)/g tissue/minute that agree with literature results reported from positron emission tomography. The proposed technique is demonstrated in the human brain using a 9.4 T MR scanner optimized for human brain imaging.

  17. Cerebral oxygen delivery and consumption during evoked neural activity

    Directory of Open Access Journals (Sweden)

    Alberto L Vazquez

    2010-06-01

    Full Text Available Increases in neural activity evoke increases in the delivery and consumption of oxygen. Beyond observations of cerebral tissue and blood oxygen, the role and properties of cerebral oxygen delivery and consumption during changes in brain function are not well understood. This work overviews the current knowledge of functional oxygen delivery and consumption and introduces recent and preliminary findings to explore the mechanisms by which oxygen is delivered to tissue as well as the temporal dynamics of oxygen metabolism. Vascular oxygen tension measurements have shown that a relatively large amount of oxygen exits pial arterioles prior to capillaries. Additionally, increases in cerebral blood flow (CBF induced by evoked neural activation are accompanied by arterial vasodilation and also by increases in arteriolar oxygenation. This increase contributes not only to the down-stream delivery of oxygen to tissue, but also to delivery of additional oxygen to extra-vascular spaces surrounding the arterioles. On the other hand, the changes in tissue oxygen tension due to functional increases in oxygen consumption have been investigated using a method to suppress the evoked CBF response. The functional decreases in tissue oxygen tension induced by increases in oxygen consumption are slow to evoked changes in CBF under control conditions. Preliminary findings obtained using flavoprotein autofluorescence imaging suggest cellular oxidative metabolism changes at a faster rate than the average changes in tissue oxygen. These issues are important in the determination of the dynamic changes in tissue oxygen metabolism from hemoglobin-based imaging techniques such as blood oxygenation-level dependent functional magnetic resonance imaging (fMRI.

  18. Cerebral oxygenation is reduced during hyperthermic exercise in humans

    DEFF Research Database (Denmark)

    Rasmussen, P.; Nybo, Lars; Volianitis, Stefanos;

    2010-01-01

    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 eight males [27 +/- 6 years (mean +/- SD) and maximal oxygen uptake (VO(2max)) 63 +/- 6 mL kg(-1) min(-1)]. Results: The CBF, CMRO(2) and P(mito)O(2) remained stable during 1 h of moderate cycling (170 +/- 11 W, approximately 50% of VO(2max), RPE 9-12) in normothermia (core temperature of 37.8 +/- 0...

  19. 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

    venous noradrenaline, and falling arterial carbon dioxide tension (P aCO 2) (R(2) ≥ 0.41, P ≤ 0.01) whereas CCA flow and conductance were related to elevated blood temperature. In conclusion, dehydration accelerated the decline in CBF by decreasing P aCO 2 and enhancing vasoconstrictor activity. However......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...

  20. Metabolic control of resting hemispheric cerebral blood flow is oxidative, not glycolytic

    OpenAIRE

    Powers, William. J.; Videen, Tom O.; Markham, Joanne; Walter, Vonn; Perlmutter, Joel S.

    2011-01-01

    Although the close regional coupling of resting cerebral blood flow (CBF) with both cerebral metabolic rate of oxygen (CMRO2) and cerebral metabolic rate of glucose (CMRglc) within individuals is well documented, there are few data regarding the coupling between whole brain flow and metabolism among different subjects. To investigate the metabolic control of resting whole brain CBF, we performed multivariate analysis of hemispheric CMRO2, CMRglc, and other covariates as predictors of resting ...

  1. Cerebral blood flow and metabolism during isoflurane-induced hypotension in patients subjected to surgery for cerebral aneurysms

    DEFF Research Database (Denmark)

    Madsen, J B; Cold, G E; Hansen, E S;

    1987-01-01

    Cerebral blood flow and cerebral metabolic rate for oxygen were measured during isoflurane-induced hypotension in 10 patients subjected to craniotomy for clipping of a cerebral aneurysm. Flow and metabolism were measured 5-13 days after the subarachnoid haemorrhage by a modification of the classi......Cerebral blood flow and cerebral metabolic rate for oxygen were measured during isoflurane-induced hypotension in 10 patients subjected to craniotomy for clipping of a cerebral aneurysm. Flow and metabolism were measured 5-13 days after the subarachnoid haemorrhage by a modification......). Controlled hypotension to an average MAP of 50-55 mm Hg was induced by increasing the dose of isoflurane, and maintained at an inspired concentration of 2.2 +/- 0.2%. This resulted in a significant decrease in CMRO2 (to 1.73 +/- 0.16 ml/100 g min-1), while CBF was unchanged. After the clipping...

  2. Cerebral oxygen extraction, oxygen consumption, and regional cerebral blood flow during the aura phase of migraine

    DEFF Research Database (Denmark)

    Friberg, L; Olesen, Jes; Lassen, N A

    1994-01-01

    The aura phase of migraine is associated with focal blood flow changes, but it has been largely unknown whether these changes are correlated to changes in the cerebral metabolism.......The aura phase of migraine is associated with focal blood flow changes, but it has been largely unknown whether these changes are correlated to changes in the cerebral metabolism....

  3. The significance of changes in cerebral oxygen and glucose metabolism in patients with cerebral hemorrhage caused by acute hypertension%急性高血压脑出血患者脑糖氧代谢变化及意义

    Institute of Scientific and Technical Information of China (English)

    马骏; 陈锷峰; 屠传建; 钱辉; 骆明; 顾志伟; 张建民

    2014-01-01

    Objective To study the clinical significance of early changes in cerebral oxygen and glucose metabolism in patients with cerebral hemorrhage and with Glasgow coma score (GCS) of 5-8 caused by acute hypertension in order to find relationship between those changes and prognosis.Methods From January 1,2011 to June 30,2012,a cohort of 43 patients with cerebral hemorrhage caused by acute hypertension were enrolled for retrospective study.Radial artery and internal jugular vein were separately cannulated retrogradely for collecting blood for blood gas analysis and blood glucose tests carried out 24 hours after the onset of the cerebral hemorrhage and then every 6-8 hours and as any major changes in physical signs of patients occurred.And this monitoring kept for consecutive 3 days.The data of these laboratory findings were analyzed and calculated to determine internal jugular vein oxygen saturation (SjVO2),cerebral oxygen utilization rate (CEO2),cerebral arterio-venous oxygen difference (AVDO2),arterio-venous blood glucose difference (V-Aglu),arterio-venous lactic acid difference (V-Alac) and absolute value of carbon dioxide pressure difference between jugular vein and artery (V-APCO2).All patients met the diagnostic criteria of hypertensive cerebral hemorrhage revised by the 4th National Academic Conference on cerebrovascular disease in 1995 requiring diagnosis confirmed by brain CT,admitted within 24 hours of onset,Glasgow coma score (GCS) 5-8 and a history of hypertension.Exclusion criteria were:cerebral hemorrhage caused by traumatic intracranial hematoma,spontaneous subarachnoid hemorrhage,arteriovenous malformation and Moyamoya disease,intracranial tumor apoplexy,cerebral bleeding derived from the disturbance of blood coagulation system,and cerebral hemorrhagic infarction.According to the short-term prognosis,the patients were divided into the death group and the survival group.Then the differences in biomarkers mentioned above between two groups were compared to

  4. Cerebral Tissue Oxygenation during Immediate Neonatal Transition and Resuscitation

    Science.gov (United States)

    Pichler, Gerhard; Schmölzer, Georg M.; Urlesberger, Berndt

    2017-01-01

    This article provides a review of cerebral tissue oxygenation during immediate transition after birth in human neonates. Recommended routine monitoring, especially if resuscitation is needed, during this period includes arterial oxygen saturation and heart rate measured by pulse oximetry and electrocardiogram. However, there is increasing interest to monitor in addition with near-infrared spectroscopy (NIRS) the oxygenation of the brain. There is a different pattern of increase between cerebral tissue oxygenation and arterial oxygen saturation during the immediate transition, with cerebral tissue oxygenation reaching a plateau faster than arterial oxygen saturation. Differences can be explained, since cerebral tissue oxygenation is not only affected by arterial oxygen saturation but also by cerebral blood flow, hemoglobin content, and cerebral oxygen consumption. Normal values have already been established for different devices, gestational ages, and modes of delivery in neonates without any medical support. Cerebral hypoxia during immediate transition might cause brain damage. In preterm neonates with cerebral hemorrhage evolving in the first week after birth, the cerebral tissue oxygenation is already lower in the first minutes after birth compared to preterm neonates without cerebral hemorrhage. Using cerebral NIRS in combination with intervention guidelines has been shown to reduce the burden of cerebral hypoxia in preterm neonates. Cerebral tissue oxygenation during immediate transition seems to have an impact on outcome, whereby NIRS monitoring is feasible and has the advantage of continuous, non-invasive recording. The impact of NIRS monitoring and interventions on short- and long-term outcomes still need to be evaluated. PMID:28280719

  5. Cerebral vascular control and metabolism in heat stress

    DEFF Research Database (Denmark)

    Bain, Anthony R; Nybo, Lars; Ainslie, Philip N

    2015-01-01

    in cerebral oxygen extraction. However, severe increases in whole-body and brain temperature may increase blood-brain barrier permeability, potentially leading to cerebral vasogenic edema. The cerebrovascular challenges associated with hyperthermia are of paramount importance for populations with compromised......This review provides an in-depth update on the impact of heat stress on cerebrovascular functioning. The regulation of cerebral temperature, blood flow, and metabolism are discussed. We further provide an overview of vascular permeability, the neurocognitive changes, and the key clinical...... implications and pathologies known to confound cerebral functioning during hyperthermia. A reduction in cerebral blood flow (CBF), derived primarily from a respiratory-induced alkalosis, underscores the cerebrovascular changes to hyperthermia. Arterial pressures may also become compromised because of reduced...

  6. Effects of propofol versus sevoflurane on cerebral oxygenation and cognitive outcome in patients with impaired cerebral oxygenation

    Directory of Open Access Journals (Sweden)

    Guo JY

    2016-01-01

    Full Text Available Jun-ying Guo,1,* Jie-yu Fang,1,* San-rong Xu,2 Ming Wei,1 Wen-qi Huang1 1Department of Anesthesia, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, 2Department of Anesthesia, Zhangzhou Municipal Hospital of Fujian Province, Zhangzhou, Fujian, People’s Republic of China *These authors contributed equally to this work Background: Postoperative neurocognitive dysfunction induced by anesthetics, particularly in elderly patients with impaired oxygenation, is a common complication of surgery and is eliciting increased interest in clinical practice. To investigate the effects of anesthetics on neurocognition, we compared the effects of propofol versus sevoflurane on cerebral oxygenation and cognitive outcome in patients with impaired cerebral oxygenation undergoing general anesthesia. Methods: Sixty-three patients with impaired cerebral oxygenation (jugular venous bulb oxygen saturation [SjvO2] <50% or cerebral blood flow/cerebral metabolic rate of oxygen ([CBF/CMRO2] ≤15% undergoing elective abdominal surgery were randomly allocated into propofol group (group P or sevoflurane group (group S. The clinical parameters and jugular venous bulb blood gas analysis were monitored throughout the surgical procedure. Cognitive function was assessed with the mini-mental state examination and Montreal Cognitive Assessment at day 1 and day 7 following surgery. S100β protein in plasma was measured using enzyme-linked immunosorbent assay. Results: The SjvO2 increased during anesthesia induction and surgery when compared to baseline but had no significant difference between group P and group S. When compared to baseline, the CBF/CMRO2 was increased only at the end of surgery and extubation in group P; however, the CBF/CMRO2 in group S was increased during anesthesia induction at 1 hour, 2 hours, end of surgery, and extubation. Furthermore, the CBF/CMRO2 in group S was significantly higher than that in group P during anesthesia

  7. 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.

  8. The coupling of cerebral blood flow and oxygen metabolism with brain activation is similar for simple and complex stimuli in human primary visual cortex.

    Science.gov (United States)

    Griffeth, Valerie E M; Simon, Aaron B; Buxton, Richard B

    2015-01-01

    Quantitative functional MRI (fMRI) experiments to measure blood flow and oxygen metabolism coupling in the brain typically rely on simple repetitive stimuli. Here we compared such stimuli with a more naturalistic stimulus. Previous work on the primary visual cortex showed that direct attentional modulation evokes a blood flow (CBF) response with a relatively large oxygen metabolism (CMRO2) response in comparison to an unattended stimulus, which evokes a much smaller metabolic response relative to the flow response. We hypothesized that a similar effect would be associated with a more engaging stimulus, and tested this by measuring the primary human visual cortex response to two contrast levels of a radial flickering checkerboard in comparison to the response to free viewing of brief movie clips. We did not find a significant difference in the blood flow-metabolism coupling (n=%ΔCBF/%ΔCMRO2) between the movie stimulus and the flickering checkerboards employing two different analysis methods: a standard analysis using the Davis model and a new analysis using a heuristic model dependent only on measured quantities. This finding suggests that in the primary visual cortex a naturalistic stimulus (in comparison to a simple repetitive stimulus) is either not sufficient to provoke a change in flow-metabolism coupling by attentional modulation as hypothesized, that the experimental design disrupted the cognitive processes underlying the response to a more natural stimulus, or that the technique used is not sensitive enough to detect a small difference.

  9. Sympathetic influence on cerebral blood flow and metabolism during exercise in humans

    DEFF Research Database (Denmark)

    Seifert, Thomas; Secher, Niels H

    2011-01-01

    This review focuses on the possibility that autonomic activity influences cerebral blood flow (CBF) and metabolism during exercise in humans. Apart from cerebral autoregulation, the arterial carbon dioxide tension, and neuronal activation, it may be that the autonomic nervous system influences CBF......, but increases during cycling exercise. The increase in CMRO(2) is unaffected by beta-adrenergic blockade even though CBF is reduced suggesting that cerebral oxygenation becomes critical and a limited cerebral mitochondrial oxygen tension may induce fatigue. Also, sympathetic activity may drive cerebral non...

  10. Transcranial laser stimulation improves human cerebral oxygenation

    OpenAIRE

    2016-01-01

    Background and Objective Transcranial laser stimulation of the brain with near‐infrared light is a novel form of non‐invasive photobiomodulation or low‐level laser therapy (LLLT) that has shown therapeutic potential in a variety of neurological and psychological conditions. Understanding of its neurophysiological effects is essential for mechanistic study and treatment evaluation. This study investigated how transcranial laser stimulation influences cerebral hemodynamics and oxygenation in th...

  11. Purine Metabolism in Acute Cerebral Ischemia

    Directory of Open Access Journals (Sweden)

    Ye. V. Oreshnikov

    2008-01-01

    Full Text Available Objective: to study the specific features of purine metabolism in clinically significant acute cerebral ischemia. Subjects and materials. Three hundred and fifty patients with the acutest cerebral ischemic stroke were examined. The parameters of gas and electrolyte composition, acid-base balance, the levels of malonic dialdehyde, adenine, guanine, hypox-anthine, xanthine, and uric acid, and the activity of xanthine oxidase were determined in arterial and venous bloods and spinal fluid. Results. In ischemic stroke, hyperuricemia reflects the severity of cerebral metabolic disturbances, hemodynamic instability, hypercoagulation susceptiility, and the extent of neurological deficit. In ischemic stroke, hyperuri-corachia is accompanied by the higher spinal fluid levels of adenine, guanine, hypoxanthine, and xanthine and it is an indirect indicator of respiratory disorders of central genesis, systemic acidosis, hypercoagulation susceptibility, free radical oxidation activation, the intensity of a stressor response to cerebral ischemia, cerebral metabolic disturbances, the depth of reduced consciousness, and the severity of neurological deficit. Conclusion. The high venous blood activity of xanthine oxidase in ischemic stroke is associated with the better neurological parameters in all follow-up periods, the better early functional outcome, and lower mortality rates. Key words: hyperuricemia, stroke, xanthine oxidase, uric acid, cerebral ischemia.

  12. Cerebral blood flow, oxidative metabolism and cerebrovascular carbon dioxide reactivity in patients with acute bacterial meningitis

    DEFF Research Database (Denmark)

    Møller, Kirsten; Strauss, Gitte Irene; Thomsen, Gerda;

    2002-01-01

    BACKGROUND: The optimal arterial carbon dioxide tension (P(a)CO(2)) in patients with acute bacterial meningitis (ABM) is unknown and controversial. The objective of this study was to measure global cerebral blood flow (CBF), cerebrovascular CO(2) reactivity (CO(2)R), and cerebral metabolic rates...... to baseline ventilation, whereas CMR(glu) increased. CONCLUSION: In patients with acute bacterial meningitis, we found variable levels of CBF and cerebrovascular CO(2) reactivity, a low a-v DO(2), low cerebral metabolic rates of oxygen and glucose, and a cerebral lactate efflux. In these patients...

  13. Relationship Between Cerebral Oxygenation and Hemodynamic and Oxygen Transport Parameters in Surgery for Acquired Heart Diseases

    Directory of Open Access Journals (Sweden)

    A. I. Lenkin

    2012-01-01

    Full Text Available Objective: to evaluate the relationship between cerebral oxygenation and hemodynamic and oxygen transport parameters in surgical correction of concomitant acquired heart diseases. Subjects and methods. Informed consent was received from 40 patients who required surgery because of concomitant (two or more acquired heart defects. During procedure, perioperative monitoring of oxygen transport and cerebral oxygenation was performed with the aid of PiCCO2 monitor (Pulsion Medical Systems, Germany and a Fore-Sight cerebral oximeter (CASMED, USA. Anesthesia was maintained with propofol and fen-tanyl, by monitoring the depth of anesthesia. Early postoperative intensive therapy was based on the protocol for early targeted correction of hemodynamic disorders. Oxygen transport and cerebral oxygenation parameters were estimated intraopera-tively and within 24 postoperative hours. A statistical analysis including evaluation of Spearman correlations was performed with the aid of SPSS 15.0. Results. During perfusion, there was a relationship between cerebral oximetry values and hemat-ocrit levels, and oxygen partial pressure in the venous blood. Furthermore, a negative correlation between cerebral oximetry values and blood lactate levels was found 30 minutes after initiation of extracorporeal circulation (EC. During the study, there was a positive correlation between cerebral oxygenation and values of cardiac index, central venous saturation, and oxygen delivery index. There was a negative relationship between cerebral oxygenation and extravascular lung water at the beginning of surgery and a correlation between cerebral oximetry values and oxygenation index by the end of the first 24 postoperative hours. Conclusion. The cerebral oxygenation values correlate -with the main determinants of oxygen transport during EC and after cardiac surgical procedures. Cerebral oximetry may be used in early targeted therapy for the surgical correction of acquired combined

  14. Lipopolysaccharide infusion enhances dynamic cerebral autoregulation without affecting cerebral oxygen vasoreactivity in healthy volunteers

    DEFF Research Database (Denmark)

    Berg, Ronan Mg; Plovsing, Ronni R; Evans, Kevin A;

    2013-01-01

    Sepsis may be associated with disturbances in cerebral oxygen transport and cerebral haemodynamic function, thus rendering the brain particularly susceptible to hypoxia. The purpose of this study was to assess the impact of isocapnic hypoxia and hyperoxia on dynamic cerebral autoregulation...... in a human-experimental model of the systemic inflammatory response during the early stages of sepsis....

  15. Modeling of cerebral oxygen transport based on in vivo microscopic imaging of microvascular network structure, blood flow and oxygenation

    Directory of Open Access Journals (Sweden)

    Louis Gagnon

    2016-08-01

    Full Text Available 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.

  16. 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...

  17. Cerebral aspects of neonatal extracorporeal membrane oxygenation: a review.

    NARCIS (Netherlands)

    Mol, A.C. de; Liem, K.D.; Heijst, A.F.J. van

    2013-01-01

    Background: Neonatal extracorporeal membrane oxygenation (ECMO) is a lifesaving therapeutic approach in newborns suffering from severe, but potentially reversible, respiratory insufficiency, mostly complicated by neonatal persistent pulmonary hypertension. However, cerebral damage, intracerebral hem

  18. Research on the effect of remifentanil on cerebral oxygen metabolism and cerebral blood flow of patients with severe brain injury%瑞芬太尼对重型颅脑损伤患者脑氧代谢及脑血流的影响

    Institute of Scientific and Technical Information of China (English)

    王言武

    2014-01-01

    Objective To investigate the effect of remifentanil on cerebral oxygen metabolism and cerebral blood flow of patients with severe brain injury.Methods Retrospective analysis of the clinical data of the 64 cases with severe head injury ad-mitted to our hospital was processed. According to the anesthetic drugs ,64 cases were divided into treatment group and control group ,the control group was treated with fentanyl for anesthesia ,the treatment group was treated with remifentanil for anes-thesia. Cerebral oxygen metabolism and hemodynamic indexes of the two groups before anesthesia and after anesthesia for 10min were compared.Results Before anesthesia ,brain oxygen metabolism and hemodynamic parameters of the two groups were not significantly different ,P>0.05 ;10 min after anesthesia ,CERO2 of the treatment group was significantly higher than that of the control group ,CjvO2 ,Da-jvO2 are significantly lower than that of the control group ,P<0.05;Qmean ,Wv of the treatment group were significantly higher than those of the control group ;DR was significantly lower than that of the control group ,P<0.05.Conclusion Remifentanil anesthesia for patients with severe head injury surgery can improve cerebral oxygen metabolism and cerebral blood flow ,has high security.%目的:探讨瑞芬太尼对重型颅脑损伤患者脑氧代谢的影响。方法回顾性分析我院收治的64例重型颅脑损伤患者的临床资料,根据麻醉药物不同分为治疗组和对照组,对照组采用芬太尼麻醉,治疗组采用瑞芬太尼麻醉,比较2组患者麻醉前、麻醉后10 min时脑氧代谢指标和血流动力学指标。结果麻醉前2组患者的脑氧代谢指标和血流动力学指标比较均无显著性差异(P>0.05);麻醉后10 min治疗组CERO2显著高于对照组,CjvO2、Da-jvO2均显著低于对照组(P<0.05);治疗组Qmean、Wv显著高于对照组,DR显著低于对照组(P<0.05)。结论瑞芬太尼在重型颅脑损

  19. Cerebral blood flow and metabolism during sleep.

    Science.gov (United States)

    Madsen, P L; Vorstrup, S

    1991-01-01

    A review of the current literature regarding sleep-induced changes in cerebral blood flow (CBF) and cerebral metabolic rate (CMR) is presented. Early investigations have led to the notion that dreamless sleep was characterized by global values of CBF and CMR practically at the level of wakefulness, while rapid eye movement (REM) sleep (dream sleep) was a state characterized by a dramatically increased level of CBF and possibly also of CMR. However, recent investigations firmly contradict this notion. Investigations on CBF and CMR performed during non-REM sleep, taking the effect of different levels of sleep into consideration, show that light sleep (stage II) is characterized by global levels of CBF and CMR only slightly reduced by 3-10% below the level associated with wakefulness, whereas CBF and CMR during deep sleep (stage III-IV) is dramatically reduced by 25-44%. Furthermore, recent data indicate that global levels of CBF and CMR are about the same during REM sleep as in wakefulness. On the regional level, deep sleep seems to be associated with a uniform decrease in regional CBF and CMR. Investigations concerning regional CBF and CMR during REM sleep are few but data from recent investigations seem to identify site-specific changes in regional CBF and CMR during REM sleep. CBF and CMR are reflections of cerebral synaptic activity and the magnitude of reduction in these variables associated with deep sleep indicates that overall cerebral synaptic activity is reduced to approximately one-half the level associated with wakefulness, while cerebral synaptic activity levels during REM sleep are similar to wakefulness. However, even though the new understanding of CBF and CMR during sleep provides significant and important information of the brain's mode of working during sleep, it does not at its current state identify the physiological processes involved in sleep or the physiological role of sleep.

  20. Cerebral energy metabolism during mitochondrial dysfunction induced by cyanide in piglets

    DEFF Research Database (Denmark)

    Nielsen, Troels Halfeld; Olsen, N.V.; Toft, P;

    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...... 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 cerebral lactate...... with a normal or elevated pyruvate level. The metabolic pattern is different from cerebral ischemia, which is characterised by simultaneous decreases in intracerebral pyruvate and PbtO2 . The study supports the hypothesis that cerebral ischemia and mitochondrial dysfunction may be identified and separated...

  1. Prenatal tobacco exposure influences cerebral oxygenation in preterm infants

    NARCIS (Netherlands)

    Verhagen, Elise A.; ter Horst, Hendrik J.; Kooi, Elisabeth M. W.; Keating, Paul; van den Berg, Paul P.; Bos, Arend F.

    2011-01-01

    Aim: Our aim was to determine the influence of prenatal tobacco exposure on regional cerebral tissue oxygen saturation (r(c)SO(2)) and fractional tissue oxygen extraction (FTOE) in preterm infants. We hypothesized that as a result of vasoconstriction caused by prenatal tobacco exposure r(c)SO(2) wou

  2. Metabolic control of resting hemispheric cerebral blood flow is oxidative, not glycolytic.

    Science.gov (United States)

    Powers, William J; Videen, Tom O; Markham, Joanne; Walter, Vonn; Perlmutter, Joel S

    2011-05-01

    Although the close regional coupling of resting cerebral blood flow (CBF) with both cerebral metabolic rate of oxygen (CMRO(2)) and cerebral metabolic rate of glucose (CMRglc) within individuals is well documented, there are few data regarding the coupling between whole brain flow and metabolism among different subjects. To investigate the metabolic control of resting whole brain CBF, we performed multivariate analysis of hemispheric CMRO(2), CMRglc, and other covariates as predictors of resting CBF among 23 normal humans. The univariate analysis showed that only CMRO(2) was a significant predictor of CBF. The final multivariate model contained two additional terms in addition to CMRO(2): arterial oxygen content and oxygen extraction fraction. Notably, arterial plasma glucose concentration and CMRglc were not included in the final model. Our data demonstrate that the metabolic factor controlling hemispheric CBF in the normal resting brain is CMRO(2) and that CMRglc does not make a contribution. Our findings provide evidence for compartmentalization of brain metabolism into a basal component in which CBF is coupled to oxygen metabolism and an activation component in which CBF is controlled by another mechanism.

  3. Physiological meaning of cerebral oxygen saturation for piglet with hypoxia-ischemia

    Science.gov (United States)

    Ding, Haishu; Huang, Lan; Jen, Chungchien; Hwang, Betau; Lee, Zhiguang; Teng, Yichao; Zheng, Meizhi

    2005-01-01

    The physiological meaning of cerebral oxygen saturation absolute values and the oxygen metabolism of piglet with hypoxia-ischemia (HIE) were researched. The subjects were two piglets. During the total experiment of hypoxia then recovery, the regional cerebral tissue oxygen (rScO2), pulse oxygen saturation (SpO2) were detected non-invasively and the jugular oxygen saturation (SjO2), arterial oxygen saturation (SaO2) were given invasively. The results show that because SjO2 was equal to or larger than rScO2 and SaO2 > ScO2, rScO2 cannot be determined by the weighted sum of SjO2 and SaO2 which had been presented in some papers. According to above-mentioned analysis, the ecchymoma and pathological changes of the vessels due to HIE may be another contribution of rScO2. SjO2 was correlated with SaO2 (R=0.996 and 0.962 for two piglets) and the values of (SaO2-SjO2) are close to constants (29.3+/-8% and 30.3+/-8%).It means that because the subjects were under anesthesia, the oxygen consumption of cerebral tissue kept constants.

  4. 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

    BACKGROUND & AIMS: It is unclear whether patients with hepatic encephalopathy (HE) have disturbed brain oxygen metabolism and blood flow. METHODS: We measured cerebral oxygen metabolism rate (CMRO(2)) by using (15)O-oxygen positron emission tomography (PET), and cerebral blood flow (CBF) by using....../min in patients with HE, 0.47 +/- 0.02 in patients without HE, and 0.49 +/- 0.03 in healthy subjects. CMRO(2) and CBF were correlated, and both variables correlated negatively with arterial ammonia concentration. Analysis of regional values, using individual magnetic resonance co-registrations, showed...... that the 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...

  5. 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.

  6. Sympathetic influence on cerebral blood flow and metabolism during exercise in humans

    DEFF Research Database (Denmark)

    Seifert, Thomas; Secher, Niels H

    2011-01-01

    , but not by beta1-adrenergic blockade. Furthermore, endurance training appears to lower the cerebral non-oxidative carbohydrate uptake and preserve cerebral oxygenation during submaximal exercise. This is possibly related to an attenuated catecholamine response. Finally, exercise promotes brain health as evidenced......This review focuses on the possibility that autonomic activity influences cerebral blood flow (CBF) and metabolism during exercise in humans. Apart from cerebral autoregulation, the arterial carbon dioxide tension, and neuronal activation, it may be that the autonomic nervous system influences CBF...... as evidenced by pharmacological manipulation of adrenergic and cholinergic receptors. Cholinergic blockade by glycopyrrolate blocks the exercise-induced increase in the transcranial Doppler determined mean flow velocity (MCA Vmean). Conversely, alpha-adrenergic activation increases that expression of cerebral...

  7. Improved cerebral energetics and ketone body metabolism in db/db mice.

    Science.gov (United States)

    Andersen, Jens V; Christensen, Sofie K; Nissen, Jakob D; Waagepetersen, Helle S

    2017-03-01

    It is becoming evident that type 2 diabetes mellitus is affecting brain energy metabolism. The importance of alternative substrates for the brain in type 2 diabetes mellitus is poorly understood. The aim of this study was to investigate whether ketone bodies are relevant candidates to compensate for cerebral glucose hypometabolism and unravel the functionality of cerebral mitochondria in type 2 diabetes mellitus. Acutely isolated cerebral cortical and hippocampal slices of db/db mice were incubated in media containing [U-(13)C]glucose, [1,2-(13)C]acetate or [U-(13)C]β-hydroxybutyrate and tissue extracts were analysed by mass spectrometry. Oxygen consumption and ATP synthesis of brain mitochondria of db/db mice were assessed by Seahorse XFe96 and luciferin-luciferase assay, respectively. Glucose hypometabolism was observed for both cerebral cortical and hippocampal slices of db/db mice. Significant increased metabolism of [1,2-(13)C]acetate and [U-(13)C]β-hydroxybutyrate was observed for hippocampal slices of db/db mice. Furthermore, brain mitochondria of db/db mice exhibited elevated oxygen consumption and ATP synthesis rate. This study provides evidence of several changes in brain energy metabolism in type 2 diabetes mellitus. The increased hippocampal ketone body utilization and improved mitochondrial function in db/db mice, may act as adaptive mechanisms in order to maintain cerebral energetics during hampered glucose metabolism.

  8. 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

    2013-03-14

    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

  9. Reduced muscle activation during exercise related to brain oxygenation and metabolism in humans

    DEFF Research Database (Denmark)

    Rasmussen, P; Nielsen, J; Overgaard, M

    2010-01-01

    of perceived exertion (RPE), arm maximal voluntary force (MVC), and voluntary activation of elbow flexor muscles assessed with transcranial magnetic stimulation. Low intensity exercise did not produce any indication of central fatigue or marked cerebral metabolic deviations. Exercise in hypoxia (0.10) reduced...... cerebral oxygen delivery 25% and decreased 11+/-4 mmHg (PMVC and voluntary activation were reduced (PMVC...... and voluntary activation were reduced (PMVCs were similar to resting values. Exhaustive exercise provoked cerebral deoxygenation, metabolic changes and indices of fatigue similar to those observed during exercise in hypoxia...

  10. 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.

  11. New molecular knowledge towards the trigemino-cardiac reflex as a cerebral oxygen-conserving reflex.

    Science.gov (United States)

    Sandu, N; Spiriev, T; Lemaitre, F; Filis, A; Schaller, B

    2010-05-04

    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.

  12. The SafeBoosC Phase II Randomised Clinical Trial : A Treatment Guideline for Targeted Near-Infrared-Derived Cerebral Tissue Oxygenation versus Standard Treatment in Extremely Preterm Infants

    NARCIS (Netherlands)

    Pellicer, Adelina; Greisen, Gorm; Benders, Manon; Claris, Olivier; Dempsey, Eugene; Fumagalli, Monica; Gluud, Christian; Hagmann, Cornelia; Hellstroem-Westas, Lena; Hyttel-Sorensen, Simon; Lemmers, Petra; Naulaers, Gunnar; Pichler, Gerhard; Roll, Claudia; van Bel, Frank; van Oeveren, Wim; Skoog, Maria; Wolf, Martin; Austin, Topun

    2013-01-01

    Near-infrared spectroscopy-derived regional tissue oxygen saturation of haemoglobin (rSto(2)) reflects venous oxygen saturation. If cerebral metabolism is stable, rSto(2) can be used as an estimate of cerebral oxygen delivery. The SafeBoosC phase II randomised clinical trial hypothesises that the bu

  13. Effects of Yunnan Baiyao through inner layer of cerebral dura mater on cerebral perfusion and oxygen metabolism in rabbits with severe traumatic brain injury%硬脑膜夹层导入云南白药对兔重型颅脑创伤后脑灌注和氧代谢的影响

    Institute of Scientific and Technical Information of China (English)

    徐震; 吕晓皑; 尹利明; 竺国充; 张昕; 李徐; 陈祖鹏

    2012-01-01

    Objective: To explore the effects of Yunnan Baiyao through inner layer of cerebral dura mater on cerebral perfusion and oxygen metabolism in rabbits with severe traumatic brain injury. Methods: 40 New Zealand white rabbits were divided into cerebral dura mater Yunnan Baiyao group(A group), intravenous Mannitol group(B group), oral Yunnan Baiyao group (C group) and control group(D group). Record ICP, CPP and MABP. TCD measured cerebral blood flow volume. Monitor blood gas analysis in femora) artery and internal jugular venous bulb, accounting the CEO2 and D-values of glucose and lactic acid between artery and venous bulb. Results: From 12 to 36 hour after therapy: the ICP of A was highter than B, the CPP and CBFV were lower than B (P<0.05). At 48 hour: the ICP of A was highter than B and lower than C and D, the CPP was lower than B and highter than Cand D, while the CBFV of A was highter than C and D(P<0.05). From 60 to 96 hour: the ICP of A was lower than C and D, the CPP of A was highter than C and D, the CBFV of A was highter than B, C and D(P<0.05). From 36 to 96: The Glua-jv and CEO2 of A were highter than B, C and D, while the Lacjv-a was lower than B, C and D(P<0.05). Conclusion: Yunnan Baiyao through cerebral dura mater can reach effective treatment concentration in brain. By increasing the efficiency of oxygen metabolism of brain it can ameliorate brain cell hypoxia and energy metabolism handicap, adjust cerebral microcirculation, thus improves cytotoxic brain edema, decreases cerebral blood flow resistance, reduces ICP and increase the CPP and CBFV.%目的:探讨硬脑膜夹层应用云南白药对兔重型颅脑创伤后颅内压、脑血流量和脑代谢的影响.方法:将40只雄性新西兰大白兔分为硬脑膜夹层云南白药组(A组)、静脉甘露醇组(B组)、口服云南白药组(C组)和空白组(D组),制作重型颅脑创伤模型,行颅内压(ICP)监测,记录平均动脉压(MABP),计算脑灌注压(CPP),经颅多普勒(TCD)测定脑

  14. T2’-Imaging to Assess Cerebral Oxygen Extraction Fraction in Carotid Occlusive Disease: Influence of Cerebral Autoregulation and Cerebral Blood Volume

    Science.gov (United States)

    Deichmann, Ralf; Pfeilschifter, Waltraud; Hattingen, Elke; Singer, Oliver C.; Wagner, Marlies

    2016-01-01

    Purpose Quantitative T2'-mapping detects regional changes of the relation of oxygenated and deoxygenated hemoglobin (Hb) by using their different magnetic properties in gradient echo imaging and might therefore be a surrogate marker of increased oxygen extraction fraction (OEF) in cerebral hypoperfusion. Since elevations of cerebral blood volume (CBV) with consecutive accumulation of Hb might also increase the fraction of deoxygenated Hb and, through this, decrease the T2’-values in these patients we evaluated the relationship between T2’-values and CBV in patients with unilateral high-grade large-artery stenosis. Materials and Methods Data from 16 patients (13 male, 3 female; mean age 53 years) with unilateral symptomatic or asymptomatic high-grade internal carotid artery (ICA) or middle cerebral artery (MCA) stenosis/occlusion were analyzed. MRI included perfusion-weighted imaging and high-resolution T2’-mapping. Representative relative (r)CBV-values were analyzed in areas of decreased T2’ with different degrees of perfusion delay and compared to corresponding contralateral areas. Results No significant elevations in cerebral rCBV were detected within areas with significantly decreased T2’-values. In contrast, rCBV was significantly decreased (pperfusion delay and decreased T2’. Furthermore, no significant correlation between T2’- and rCBV-values was found. Conclusions rCBV is not significantly increased in areas of decreased T2’ and in areas of restricted perfusion in patients with unilateral high-grade stenosis. Therefore, T2’ should only be influenced by changes of oxygen metabolism, regarding our patient collective especially by an increase of the OEF. T2’-mapping is suitable to detect altered oxygen consumption in chronic cerebrovascular disease. PMID:27560515

  15. 不同麻醉方法对重症颅脑损伤患者脑氧代谢的影响%Effect of different anesthesia methods on cerebral oxygen metabolism in patients with severe traumatic brain injury

    Institute of Scientific and Technical Information of China (English)

    邹斌

    2013-01-01

    Objective To investigate the effects of different anesthesia methods on cerebral oxygen metabolism in patients with severe traumatic brain injury.Methods Forty-five patients with severe traumatic brain injury from March 2011 to March 2013 were divided into propofol intravenous anesthesia group(group A),sevoflurane inhalation anesthesia group(group B) and intravenous inhalational anesthesia group (group C) by random digits table method with 15 cases each.The mean artery pressure (MAP),heart rate (HR) before anesthesia,immediately after tracheal intubation,2 minutes after intubation,10 min and 30 min after operation set and operation end were observed.The oxygen content of jugular venous (SjvO2),jugular bulb venous oxygen content (Da-jvO2) and cerebral metabolic rate for oxygen (CERO2) before anesthesia induction,immediately finish anesthesia induction,30 min and 1 h after operation set and operatin end were calculated.Results The SjvO2 values in three groups were at 30 min,1 h after operation set and operation end was higher than that before anesthesia induction (group A:0.662 ±0.077,0.689 ±0.067,0.685 ±0.066 vs.0.623 ±0.083; group B:0.661 ±0.074,0.681 ±0.072,0.661 ±0.069 vs.0.598 ±0.092; group C:0.715 ± 0.072,0.743 ± 0.070,0.713 ± 0.075 vs.0.631 ± 0.078),and there was significant difference (P < 0.05).The Da-jvO2 values,CERO2 at 30 min,1 h after operation set and operation end was lower than that before anesthesia induction in three groups [group A:Da-jvO2:(41.2 ± 6.3),(41.6 ± 8.1),(44.2 ± 6.3) ml/L vs.(49.2 ± 9.2) ml/L,CERO2:(33.0 ± 1.9)%,(32.7 ± 2.0)%,(32.3 ± 1.9)% vs.(36.0 ±2.3)%; group B:Da-jvO2:(41.8 ± 5.6),(40.2 ± 6.9),(41.8 ± 5.6) ml/L vs.(51.3 ± 8.6) ml/L,CERO2:(33.2 ±2.1)%,(33.0 ±2.6)%,(32.8 ±2.1)% vs.(34.7 ±3.1)% ; group C:Da-jvO2:(39.5 ±6.8),(38.7 ±7.0),(40.2 ±6.8) ml/L vs.(48.8 ±9.7) ml/L,CERO2:(31.8 ±2.9)%,(31.5 ±3.1)%,(32.9 ±2.3)% vs.(35.1 ± 2.9)%],and there was significant difference (P

  16. Cerebral autoregulation and flow/metabolism coupling during cardiopulmonary bypass: the influence of PaCO/sub 2/

    Energy Technology Data Exchange (ETDEWEB)

    Murkin, J.M.; Farrar, J.K.; Tweed, W.A.; McKenzie, F.N.; Guiraudon, G.

    1987-09-01

    Measurement of /sup 133/Xe clearance and effluent cerebral venous blood sampling were used in 38 patients to determine the effects of cardiopulmonary bypass, and of maintaining temperature corrected or noncorrected PaCO/sub 2/ at 40 mm Hg on regulation of cerebral blood flow (CBF) and flow/metabolism coupling. After induction of anesthesia with diazepam and fentanyl, mean CBF was 25 ml X 100 g-1 X min-1 and cerebral oxygen consumption, 1.67 ml X 100 g-1 X min-1. Cerebral oxygen consumption during nonpulsatile cardiopulmonary bypass at 26 degrees C was reduced to 0.42 ml X 100 g-1 X min-1 in both groups. CBF was reduced to 14-15 ml X 100 g-1 X min-1 in the non-temperature-corrected group (n = 21), was independent of cerebral perfusion pressure over the range of 20-100 mm Hg, but correlated with cerebral oxygen consumption. In the temperature-corrected group (n = 17), CBF varied from 22 to 32 ml X 100 g-1 X min-1, and flow/metabolism coupling was not maintained (i.e., CBF and cerebral oxygen consumption varied independently). However, variation in CBF correlated significantly with cerebral perfusion pressure over the pressure range of 15-95 mm Hg. This study demonstrates a profound reduction in cerebral oxygen consumption during hypothermic nonpulsatile cardiopulmonary bypass. When a non-temperature-corrected PaCO/sub 2/ of approximately 40 mm Hg was maintained, CBF was lower, and analysis of pooled data suggested that CBF regulation was better preserved, i.e., CBF was independent of pressure changes and dependent upon cerebral oxygen consumption.

  17. 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.

  18. Effects of hyperthermia on cerebral blood flow and metabolism during prolonged exercise in humans

    DEFF Research Database (Denmark)

    Nybo, Lars; Møller, Kirsten; Volianitis, Stefanos

    2002-01-01

    The development of hyperthermia during prolonged exercise in humans is associated with various changes in the brain, but it is not known whether the cerebral metabolism or the global cerebral blood flow (gCBF) is affected. Eight endurance-trained subjects completed two exercise bouts on a cycle...... ergometer. The gCBF and cerebral metabolic rates of oxygen, glucose, and lactate were determined with the Kety-Schmidt technique after 15 min of exercise when core temperature was similar across trials, and at the end of exercise, either when subjects remained normothermic (core temperature = 37.9 degrees C...... with control at the end of exercise (43 +/- 4 vs. 51 +/- 4 ml. 100 g(-1). min(-1); P

  19. Influence of intranasal and carotid cooling on cerebral temperature balance and oxygenation

    Directory of Open Access Journals (Sweden)

    Lars eNybo

    2014-02-01

    Full Text Available The present study evaluated the influence of intranasal cooling with balloon catheters, increased nasal ventilation, or percutaneous cooling of the carotid arteries on cerebral temperature balance and oxygenation in six healthy male subjects. Aortic arch and internal jugular venous blood temperatures were measured to assess the cerebral heat balance and corresponding paired blood samples were obtained to evaluate cerebral metabolism and oxygenation at rest, following 60 min of intranasal cooling, 5 min of nasal ventilation, and 15 min with carotid cooling. Intranasal cooling induced a parallel drop in jugular venous and arterial blood temperatures by 0.30 ± 0.08 ºC (mean ± SD, whereas nasal ventilation and carotid cooling failed to lower the jugular venous blood temperature. The magnitude of the arterio-venous temperature difference across the brain remained unchanged at - 0.33 ± 0.05 ºC following intranasal and carotid cooling, but increased to - 0.44 ± 0.11 ºC (P< 0.05 following nasal ventilation. Calculated cerebral capillary oxygen tension was 43 ± 3 mmHg at rest and remained unchanged during intranasal and carotid cooling, but decreased to 38 ± 2 mmHg (P< 0.05 following increased nasal ventilation. In conclusion, percutaneous cooling of the carotid arteries and intranasal cooling with balloon catheters are insufficient to influence cerebral oxygenation in normothermic subjects as the cooling rate is only 0.3 ºC per hour and neither intranasal nor carotid cooling is capable of inducing selective brain cooling.

  20. Imaging oxygen metabolism with hyperpolarized magnetic resonance

    DEFF Research Database (Denmark)

    Schroeder, Marie; Laustsen, Christoffer

    2017-01-01

    Every tissue in the body critically depends on meeting its energetic demands with sufficient oxygen supply. Oxygen supply/demand imbalances underlie the diseases that inflict the greatest socioeconomic burden globally. The purpose of this review is to examine how hyperpolarized contrast media, used...... in combination with MR data acquisition methods, may advance our ability to assess oxygen metabolism non-invasively and thus improve management of clinical disease. We first introduce the concept of hyperpolarization and how hyperpolarized contrast media have been practically implemented to achieve translational...... and clinical research. We will then analyze how incorporating hyperpolarized contrast media could enable realization of unmet technical needs in clinical practice. We will focus on imaging cardiac and renal oxygen metabolism, as both organs have unique physiological demands to satisfy their requirements...

  1. 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

    2016-03-01

    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 1h and reperfusion for 2h with and without rapamycin (20mg/kg once daily for two days prior to ischemia). Regional cerebral blood flow was determined using a C(14)-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.

  2. Cerebral blood flow and metabolism during sleep

    DEFF Research Database (Denmark)

    Madsen, Peter Lund; Vorstrup, S

    1991-01-01

    investigations seem to identify site-specific changes in regional CBF and CMR during REM sleep. CBF and CMR are reflections of cerebral synaptic activity and the magnitude of reduction in these variables associated with deep sleep indicates that overall cerebral synaptic activity is reduced to approximately one......-half the level associated with wakefulness, while cerebral synaptic activity levels during REM sleep are similar to wakefulness. However, even though the new understanding of CBF and CMR during sleep provides significant and important information of the brain's mode of working during sleep, it does not at its...

  3. Activated oxygen alters cerebral microvascular responses in newborn pigs

    Energy Technology Data Exchange (ETDEWEB)

    Leffler, C.W.; Busiia, D.W.; Armstead, W.M.; Mirro, R.; Thelin, O. (Univ. of Tennessee, Memphis (United States))

    1990-02-26

    In piglets, cerebral ischemia/reperfusion blocks prostanoid dependent cerebral vasodilation to hypercapnia (CO{sub 2}) and hypotension but not prostanoid independent dilation to isoproterenol (Isu) or constriction to norepinephrine (NE). Ischemia/reperfusion increases activated-O{sub 2} production by piglet brains. Using cranial windows in piglets, the authors investigated the hypothesis that activated oxygen can block prostanoid dependent cerebral vasodilator responses to CO{sub 2} and hypotension without altering responses to Isu and NE. Exposure to an activated oxygen generating system of xanthine oxidase, hypoxanthine, and Fe that made about 3 times the activated-O{sub 2} on the brain surface as ischemia/reperfusion caused reversible pial arteriolar dilation. After exposure, pial arteriolar dilation was reduced to CO{sub 2} and hypotension but not to Isu. NE constrictor responses were also unaltered. H{sub 2}O{sub 2} or H{sub 2}O{sub 2} + Fe caused constriction followed by reversible dilation. After exposure, pial arteriolar dilation in response to CO{sub 2} and hypotension was not altered. However, addition of xanthine oxidase and hypoxanthine with H{sub 2}O{sub 2} and Fe totally eliminated pial arteriolar dilator responses to CO{sub 2} and hypotension but did not decrease dilation caused by Isu or constriction caused by NE. The authors conclude that activated oxygen could produce the altered prostanoid dependent pial arteriolar responses observed following ischemia in piglets.

  4. The Coupling of Cerebral Metabolic Rate of Glucose and Cerebral Blood Flow In Vivo

    DEFF Research Database (Denmark)

    Hasselbalch, Steen; Paulson, Olaf Bjarne

    2012-01-01

    The energy supplied to the brain by metabolic substrate is largely utilized for maintaining synaptic transmission. In this regulation cerebral blood flow and glucose consumption is tightly coupled as well in the resting condition as during activation. Quantification of cerebral blood flow...... not used for aerobic metabolism. Although some of the excess glucose uptake can be explained by lactate production, this phenomenon can still not account for the excess glucose uptake. Thus, more complex metabolic patterns in the brain might be reflected in the excess glucose uptake during activation...

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

    Science.gov (United States)

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

    2016-01-01

    The purpose of this study was to determine the relationship between cerebral tissue oxygen saturation and cerebral blood volume in patients with traumatic brain injury. Perfusion computed tomography of the brain was performed in 25 patients with traumatic brain injury together with simultaneous SctO2 level measurement using cerebral near-infrared oxymetry. The mean age of the injured persons was 34.5±15.6 years (range 15-65); 14 men, 11 women. The Injury Severity Score (ISS) values were 44.4±9.7 (range 25-81). The Glasgow Coma Score (GCS) mean value before the study was 10.6±2.1 (range 5-13). SctO2 ranged from 51 to 89%, mean 62±8.2%. Cerebral blood volume (CBV) values were 2.1±0.67 ml/100 g (min 1.1; max 4.3 ml/100 g). Cerebral blood flow (CBF) was 31.99±13.6 ml/100 g×min. Mean transit time (MTT) values were 5.7±4.5 s (min 2.8; max 34.3 s). The time to peak (TTP) was 22.2±3.1 s. A statistically significant correlation was found between SctO2 level and cerebral blood volume (CBV) level (R=0.9; pperfusion.

  6. Neuroprotection of hyperbaric oxygen therapy in sub-acute traumatic brain injury:not by immediately improving cerebral oxygen saturation and oxygen partial pressure

    Institute of Scientific and Technical Information of China (English)

    Bao-chun Zhou; Li-jun Liu; Bing Liu

    2016-01-01

    Although hyperbaric oxygen (HBO) therapy can promote the recovery of neural function in patients who have suffered traumatic brain injury (TBI), the underlying mechanism is unclear. We hypothesized that hyperbaric oxygen treatment plays a neuroprotective role in TBI by increasing regional transcranial oxygen saturation (rSO2) and oxygen partial pressure (PaO2). To test this idea, we compared two groups:a control group with 20 healthy people and a treatment group with 40 TBI patients. The 40 patients were given 100% oxygen of HBO for 90 minutes. Changes in rSO2 were measured. The controls were also examined for rSO2 and PaO2, but received no treatment. rSO2 levels in the patients did not differ signiifcantly after treatment, but levels before and after treatment were signiifcantly lower than those in the control group. PaO2 levels were signiifcantly decreased after the 30-minute HBO treatment. Our ifndings suggest that there is a disorder of oxygen metabolism in patients with sub-acute TBI. HBO does not immediately affect cerebral oxygen metabolism, and the underlying mechanism still needs to be studied in depth.

  7. 早期脓毒症大鼠脑氧代谢与乳酸的变化%Preliminary study of cerebral oxygen metabolism and change of blood lactate in early stage of sepsis in rats

    Institute of Scientific and Technical Information of China (English)

    钱欣; 郑峥; 汤罗嘉; 陈锋

    2011-01-01

    Objective To observe the change of cerebral oxygen metablism and the level of blood lactate in early stage of sepsis in rats.Method Sixty-four SD rats were randomly(random number)divided into septic group and control group.The sepsis model of rat was made by lipopolysaccharide (LPS,10 mg/kg)injected intra-abdominally,and rats of control group were treated with the same amount of physiological saline instead.And each group was further divided into 4 sub-groups of4 h,6 h,12 h and 24 h after treatment.At each interval,blood samples were obtained via jugular vein for detecting blood oxygen saturation (Sjv02)and blood lactate(LA).The blood oxygen saturation(Sa02)of ventral aorta was also measured.Arteriovenous oxygen content difference (AVD02) and oxygen extraction fraction (OEF) were studied.These four variables were analyzed and compared between two groups.Results The AVD02 and OEF in sepsis group were higher than those in control groups of 3 h,6 h and 12 h (P0.05).LA in sepsis group was higher than that in control group in each interval (P0.05).脓毒症组各时间点LA含量与对照组相比均有不同程度升高,差异具有统计学意义(P<0.05).结论 脓毒症早期可出现脑贯注及脑氧摄取的增强;Sjv02,AVDO2,OEF结合LA水平的监测,能更准确的评估脓毒症早期脑供氧、耗氧和脑贯注状态.

  8. Effects of fluid restriction in combination with small dose of norepinephrine on cerebral oxygen metabolism in elderly patients undergoing gastrointestinal surgery%限制性输液复合小剂量去甲肾上腺素对胃肠道手术老年患者脑氧代谢的影响

    Institute of Scientific and Technical Information of China (English)

    邱晓东; 居斌华; 叶卉; 陆新健; 景亮; 汤文浩

    2015-01-01

    Objective To evaluate the effects of fluid restriction in combination with small dose of norepinephrine on cerebral oxygen metabolism in elderly patients undergoing gastrointestinal surgery.Methods Forty elderly patients of both sexes,aged 65-80 yr,with body mass index of 18-24 kg/m2,of ASA physical status Ⅰ or Ⅱ (NYHA Ⅰ or Ⅱ),with left ventricular ejection fraction≥50%,undergoing elective gastrointestinal surgery,were randomly divided into 2 groups (n =20 each) using a random number table:routine fluid administration group (group S) and restricted fluid administration + small dose of norepinephrine group (group RN).In group S,lactated Ringer's solution was given routinely,ephedrine 5 mg (per time) was injected intravenously,and MAP was maintained ≥ 65 mmHg during operation.In group RN,lactated Ringer's solution was infused intravenously at 5 ml · kg-1 · h-1 starting from 30 min before anesthesia,norepinephrine was infused intravenously at 0.01-0.03 μg · kg-1 · min-1 after induction of anesthesia,and MAP was maintained ≥ 65 mmHg.Intraoperative blood loss was replaced with the equal volume of 6% hydroxyethyl starch 130/0.4 sodium chloride injection in both groups.At 5 min before skin incision,1 and 2 h after skin incision and postanesthesia care unit discharge time,arterial and jugular bulb venous blood samples were obtained for blood gas analysis,and arterial oxygen content,jugular bulb venous oxygen content,arteriovenous oxygen content difference,cerebral oxygen extraction rate,and the ratio of cerebral blood flow to cerebral oxygen metabolic rate were calculated.Results There were no significant differences between the two groups in arterial oxygen content,jugular bulb venous oxygen content,arteriovenous oxygen content difference,cerebral oxygen extraction rate,and the ratio of cerebral blood flow to cerebral oxygen metabolic rate.Conclusion Fluid restriction combined with small dose of norepinephrine produces no effects on cerebral oxygen

  9. Cerebral blood flow and oxidative metabolism during human endotoxemia

    DEFF Research Database (Denmark)

    Møller, Kirsten; Strauss, Gitte Irene; Qvist, Jesper;

    2002-01-01

    The proinflammatory cytokine, tumor necrosis factor-alpha (TNF-alpha), has been suggested to mediate septic encephalopathy through an effect on cerebral blood flow (CBF) and metabolism. The effect of an intravenous bolus of endotoxin on global CBF, metabolism, and net flux of cytokines...... and catecholamines was investigated in eight healthy young volunteers. Cerebral blood flow was measured by the Kety-Schmidt technique at baseline (during normocapnia and voluntary hyperventilation for calculation of subject-specific cerebrovascular CO reactivity), and 90 minutes after an intravenous bolus...

  10. 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...

  11. 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.

  12. Neonatal cerebral oxygenation is not linked to foetal vasculitis and predicts intraventricular haemorrhage in preterm infants

    DEFF Research Database (Denmark)

    Sorensen, Line C; Maroun, Lisa L; Borch, Klaus;

    2008-01-01

    Aim: The aim of the study was to compare the cerebral tissue oxygenation index (c-TOI) measured by near infrared spectroscopy (NIRS) in infants with and without foetal vasculitis. Methods: Twenty-four infants with placental signs of a foetal inflammatory response (FIR), foetal vasculitis, were.......002). Conclusion: Cerebral oxygenation was not affected in the first day of life in preterm infants born with foetal vasculitis, while cerebral oxygenation in infants that later developed intraventricular haemorrhage was impaired....

  13. Neonatal cerebral oxygenation is not linked to foetal vasculitis and predicts intraventricular haemorrhage in preterm infants

    DEFF Research Database (Denmark)

    Sørensen, Line Carøe; Maroun, Lisa Leth; Borch, K.;

    2008-01-01

    AIM: The aim of the study was to compare the cerebral tissue oxygenation index (c-TOI) measured by near infrared spectroscopy (NIRS) in infants with and without foetal vasculitis. METHODS: Twenty-four infants with placental signs of a foetal inflammatory response (FIR), foetal vasculitis, were.......002). CONCLUSION: Cerebral oxygenation was not affected in the first day of life in preterm infants born with foetal vasculitis, while cerebral oxygenation in infants that later developed intraventricular haemorrhage was impaired Udgivelsesdato: 2008/11...

  14. Cerebral glucose metabolism in patients with spasmodic torticollis

    NARCIS (Netherlands)

    MagyarLehmann, S; Antonini, A; Roelcke, U; Maguire, RP; Missimer, J; Leenders, KL

    1997-01-01

    The pathophysiology of spasmodic torticollis is not clear. Basal ganglia dysfunction has been suggested to underlie this clinical syndrome. We studied resting cerebral glucose metabolism in 10 spasmodic torticollis patients and 10 healthy controls by using positron-emission tomography and [F-18]2-fl

  15. Effects of nitrous oxide on cerebral haemodynamics and metabolism during isoflurane anaesthesia in man

    Energy Technology Data Exchange (ETDEWEB)

    Algotsson, L.; Messeter, K. (Department of Anaesthesiology, University Hospital, Lund (Sweden)); Rosen, I. (Department of Clinical Neurophysiology, University Hospital, Lund (Sweden)); Holmin, T. (Department of Surgery, University Hospital, Lund (Sweden))

    1992-01-01

    Seven normoventilated and five hyperventilated healthy adults undergoing cholecystectomy and anaesthetized with methohexitone, fentanyl and pancuronium were studied with measurement of cerebral blood flow (CBF), cereal metabolic rate of oxygen (CMRo[sub 2]), and quantified electroencephalography (EEG) under two sets of conditions: (1) 1.7% end-tidal concentration of isoflurane in air/oxygen: (2) 0.85% end-tidal concentration of isoflurane in nitrous oxide (N[sub 2]O)/oxygen. The object was to study the effects of N[sub 2]O during isoflurane anaesthesia on cerebral circulation, metabolism and neuroelectric activity. N[sub 2]O in the anaesthetic gas mixture caused a 43% (P<0.05) increase in CBF during normocarbic conditions but no significant change during hypocapnia. CMRo[sub 2] was not significantly altered by N[sub 2]O. EEG demonstrated an activated pattern with decreased low frequency activity and increased high frequency activity. The results confirm that N[sub 2]O is a potent cerebral vasodilator in man, although the mechanisms underlying the effects on CBF are still unclear. (au).

  16. 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...

  17. Plasma pH does not influence the cerebral metabolic ratio during maximal whole body exercise

    DEFF Research Database (Denmark)

    Volianitis, Stefanos; Rasmussen, Peter; Seifert, Thomas;

    2011-01-01

    Exercise lowers the cerebral metabolic ratio of O2 to carbohydrate (glucose + 1/2 lactate) and metabolic acidosis appears to promote cerebral lactate uptake. However, the influence of pH on cerebral lactate uptake and, in turn, on the cerebral metabolic ratio during exercise is not known. Sodium.......05) following the Sal and Bicarb trials, respectively. Accordingly, the cerebral metabolic ratio decreased equally during the Sal and Bicarb trials: from 5.8 ± 0.6 at rest to 1.7 ± 0.1 and 1.8 ± 0.2, respectively. The enlarged blood-buffering capacity after infusion of Bicarb eliminated metabolic acidosis...

  18. 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

    . At high altitude at rest, arterial carbon dioxide tension, oxygen saturation, and oxygen tension were significantly reduced, and arterial oxygen content was increased because of an increase in hemoglobin concentration. Global cerebral blood flow was similar in the four conditions. Cerebral oxygen delivery...

  19. 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 tension...

  20. Smoking normalizes cerebral blood flow and oxygen consumption after 12-hour abstention

    DEFF Research Database (Denmark)

    Seyedi Vafaee, Manouchehr; Gjedde, Albert; Imamirad, Nasrin

    2015-01-01

    measurements of cerebral blood flow (CBF) and metabolic rate of oxygen (CMRO2) in 12 smokers who had refrained from smoking overnight, and in a historical group of nonsmokers, testing the prediction that overnight abstinence results in widespread, coupled reductions of CBF and CMRO2. At the end......Acute nicotine administration stimulates [14C]deoxyglucose trapping in thalamus and other regions of rat brain, but acute effects of nicotine and smoking on energy metabolism have rarely been investigated in human brain by positron emission tomography (PET). We obtained quantitative PET...... of the abstention period, global grey-matter CBF and CMRO2 were both reduced by 17% relative to nonsmokers. At 15 minutes after renewed smoking, global CBF had increased insignificantly, while global CMRO2 had increased by 11%. Regional analysis showed that CMRO2 had increased in the left putamen and thalamus...

  1. Local cerebral metabolism during partial seizures

    Energy Technology Data Exchange (ETDEWEB)

    Engel, J. Jr.; Kuhl, D.E.; Phelps, M.E.; Rausch, R.; Nuwer, M.

    1983-04-01

    Interictal and ictal fluorodeoxyglucose scans were obtained with positron CT from four patients with spontaneous recurrent partial seizures, one with epilepsia partialis continua, and one with a single partial seizure induced by electrical stimulation of the hippocampus. Ictal metabolic patterns were different for each patient studied. Focal and generalized increased and decreased metabolism were observed. Ictal hypermetabolism may exceed six times the interictal rate and could represent activation of excitatory or inhibitory synapses in the epileptogenic region and its projection fields. Hypometabolism seen on ictal scans most likely reflects postictal depression and may indicate projection fields of inhibited neurons. No quantitative relationship between alterations in metabolism and EEG or behavioral measurements of ictal events could be demonstrated.

  2. Propofol Compared to Isoflurane Inhibits Mitochondrial Metabolism in Immature Swine Cerebral Cortex

    Energy Technology Data Exchange (ETDEWEB)

    Kajimoto, Masaki; Atkinson, D. B.; Ledee, Dolena R.; Kayser, Ernst-Bernhard; Morgan, Phil G.; Sedensky, Margaret M.; Isern, Nancy G.; Des Rosiers, Christine; Portman, Michael A.

    2014-01-08

    Anesthetics used in infants and children are implicated in development of neurocognitive disorders. Although propofol induces neuroapoptosis in developing brain, the underlying mechanisms require elucidation and may have an energetic basis. We studied substrate utilization in an immature swine model anesthetized with either propofol or isoflurane for 4 hours. Piglets were infused with 13-Carbon labeled glucose and leucine in the common carotid artery in order to assess citric acid cycle (CAC) metabolism in the parietal cortex. The anesthetics produced similar systemic hemodynamics and cerebral oxygen saturation by near-infrared-spectroscopy. Compared to isoflurane, propofol depleted ATP and glycogen stores. Propofol also decreased pools of the CAC intermediates, citrate and α-ketoglutarate, while markedly increasing succinate along with decreasing mitochondrial complex II activity. Propofol also inhibited acetyl-CoA entry into the CAC through pyruvate dehydrogenase, while promoting glycolytic flux with marked accumulation of lactate. Although oxygen supply appeared similar between the anesthetic groups, propofol yielded a metabolic phenotype which resembled a hypoxic state. Propofol impairs substrate flux through the CAC in the immature cerebral cortex. These impairments occurred without systemic metabolic perturbations which typically accompany propofol infusion syndrome. These metabolic abnormalities may play a role in neurotoxity observed with propofol in the vulnerable immature brain.

  3. The effects of sevoflurane and propofol anesthesia on cerebral oxygenation in gynecological laparoscopic surgery

    OpenAIRE

    Kim, Sung-Jin; Kwon, Jae Young; Cho, Ah-Reum; Kim, Hae Kyu; Kim, Tae Kyun

    2011-01-01

    Background Both the Trendelenburg position and pneumoperitoneum with carbon dioxide have been reported to increase intracranial pressure (ICP) and to alter cerebral blood flow or cerebral blood volume. Also anesthetic agents have variable effects on cerebral hemodynamics and ICP. The present study was conducted to determine whether regional cerebral oxygen saturation (rSO2) values differ between propofol and sevoflurane anesthesia during laparoscopic surgery in the Trendelenburg position. Met...

  4. Local cerebral glucose metabolism during controlled hypoxemia in rats.

    Science.gov (United States)

    Pulsinelli, W A; Duffy, T E

    1979-05-11

    2-Deoxy-[14C]glucose metabolism was examined in brains of hypoxic, normotensive rats by autoradiography, which revealed alternating cortical columns of high and low metabolism. Activity in white matter was increased severalfold over that in adjacent gray matter. The columns were anatomically related to penetrating cortical arteries with areas between arteries demonstrating higher rates of metabolism. The results suggest the presence of interarterial tissue oxygen gradients that influence regional glucose metabolism. The relatively greater sensitivity of white matter metabolism to hypoxia may lead to an understanding of white matter damage in postanoxic leukoencephalopathy.

  5. Effect of balloon atrial septostomy on cerebral oxygenation in neonates with transposition of the great arteries

    NARCIS (Netherlands)

    van der Laan, Michelle E.; Verhagen, Elise A.; Bos, Arend F.; Berger, Rolf M. F.; Kooi, Elisabeth M. W.

    2013-01-01

    BACKGROUND: The aim of this study was to determine the effect of balloon atrial septostomy (BAS) on cerebral oxygenation in neonates with transposition of the great arteries (TGA). METHODS: In term neonates with TGA, regional cerebral tissue oxygen saturation (r(c)SO(2)) was measured using, near-inf

  6. Cerebral O2 metabolism and cerebral blood flow in humans during deep and rapid-eye-movement sleep

    DEFF Research Database (Denmark)

    Madsen, P L; Schmidt, J F; Wildschiødtz, Gordon

    1991-01-01

    It could be expected that the various stages of sleep were reflected in variation of the overall level of cerebral activity and thereby in the magnitude of cerebral metabolic rate of oxygen (CMRO2) and cerebral blood flow (CBF). The elusive nature of sleep imposes major methodological restriction...... associated with light anesthesia. During REM sleep (dream sleep) CMRO2 was practically the same as in the awake state. Changes in CBF paralleled changes in CMRO2 during both deep and REM sleep....... on examination of this question. We have now measured CBF and CMRO2 in young healthy volunteers using the Kety-Schmidt technique with 133Xe as the inert gas. Measurements were performed during wakefulness, deep sleep (stage 3/4), and rapid-eye-movement (REM) sleep as verified by standard polysomnography....... Contrary to the only previous study in humans, which reported an insignificant 3% reduction in CMRO2 during sleep, we found a deep-sleep-associated statistically highly significant 25% decrease in CMRO2, a magnitude of depression according with studies of glucose uptake and reaching levels otherwise...

  7. Ozone autohemotherapy induces long-term cerebral metabolic changes in multiple sclerosis patients.

    Science.gov (United States)

    Molinari, F; Simonetti, V; Franzini, M; Pandolfi, S; Vaiano, F; Valdenassi, L; Liboni, W

    2014-01-01

    Ozone autohemotherapy is an emerging therapeutic technique that is gaining increasing importance in treating neurological disorders. A validated and standard methodology to assess the effect of such therapy on brain metabolism and circulation is however still lacking. We used a near-infrared spectroscopy (NIRS) system to monitor the cerebral metabolism and a transcranial Doppler (TCD) to monitor the blood flow velocity in the middle cerebral arteries. Fifty-four subjects (32 neurological patients and 22 controls) were tested before, during, and after ozone autohemotherapy. We monitored the concentration changes in the level of oxygenated and deoxygenated haemoglobin, and in the level of the Cytochrome-c-oxidase (CYT-c). As a primary endpoint of the work, we showed the changes in the brain metabolism and circulation of the entire population. The concentration of oxygenated haemoglobin increased after the reinjection of the ozoned blood and remained higher than the beginning for another 1.5 hours. The concentration of the deoxygenated haemoglobin decreased during the therapy and the CYT-c concentration markedly increased about 1 hour after the reinjection. No significant changes were observed on the blood flow velocity. As secondary endpoint, we compared the NIRS metabolic pattern of 20 remitting-relapsing multiple sclerosis (MS) patients against 20 controls. We showed that by using only 7 NIRS variables it was possible to characterize the metabolic brain pattern of the two groups of subjects. The MS subjects showed a marked increase of the CYT-c activity and concentration about 40 minutes after the end of the autohemotherapy, possibly revealing a reduction of the chronic oxidative stress level typical of MS sufferers. From a technical point of view, this preliminary study showed that NIRS could be useful to show the effects of ozone autohemotherapy at cerebral level, in a long-term monitoring. The clinical result of this study is the quantitative measurement of the

  8. Ventilatory response in metabolic acidosis and cerebral blood volume in humans.

    NARCIS (Netherlands)

    Ven, M.T.P. van de; Colier, W.N.J.M.; Sluijs, M.C. van der; Oeseburg, B.; Folgering, H.T.M.

    2001-01-01

    The relationship between alterations in cerebral blood volume (CBV) and central chemosensitivity regulation was studied under neutral metabolic conditions and during metabolic acidosis. Fifteen healthy subjects (5610 years) were investigated. To induce metabolic acidosis, ammonium chloride (NH(4)Cl)

  9. PET measurements of cerebral metabolism corrected for CSF contributions

    Energy Technology Data Exchange (ETDEWEB)

    Chawluk, J.; Alavi, A.; Dann, R.; Kushner, M.J.; Hurtig, H.; Zimmerman, R.A.; Reivich, M.

    1984-01-01

    Thirty-three subjects have been studied with PET and anatomic imaging (proton-NMR and/or CT) in order to determine the effect of cerebral atrophy on calculations of metabolic rates. Subgroups of neurologic disease investigated include stroke, brain tumor, epilepsy, psychosis, and dementia. Anatomic images were digitized through a Vidicon camera and analyzed volumetrically. Relative areas for ventricles, sulci, and brain tissue were calculated. Preliminary analysis suggests that ventricular volumes as determined by NMR and CT are similar, while sulcal volumes are larger on NMR scans. Metabolic rates (18F-FDG) were calculated before and after correction for CSF spaces, with initial focus upon dementia and normal aging. Correction for atrophy led to a greater increase (%) in global metabolic rates in demented individuals (18.2 +- 5.3) compared to elderly controls (8.3 +- 3.0,p < .05). A trend towards significantly lower glucose metabolism in demented subjects before CSF correction was not seen following correction for atrophy. These data suggest that volumetric analysis of NMR images may more accurately reflect the degree of cerebral atrophy, since NMR does not suffer from beam hardening artifact due to bone-parenchyma juxtapositions. Furthermore, appropriate correction for CSF spaces should be employed if current resolution PET scanners are to accurately measure residual brain tissue metabolism in various pathological states.

  10. Prognostic value of cerebral tissue oxygen saturation during neonatal extracorporeal membrane oxygenation

    Science.gov (United States)

    Clair, Marie-Philippine; Rambaud, Jérôme; Flahault, Adrien; Guedj, Romain; Guilbert, Julia; Guellec, Isabelle; Durandy, Amélie; Demoulin, Maryne; Jean, Sandrine; Mitanchez, Delphine; Chalard, François; Sileo, Chiara; Carbajal, Ricardo; Renolleau, Sylvain

    2017-01-01

    Objectives Extracorporeal membrane oxygenation support is indicated in severe and refractory respiratory or circulatory failures. Neurological complications are typically represented by acute ischemic or hemorrhagic lesions, which induce higher morbidity and mortality. The primary goal of this study was to assess the prognostic value of cerebral tissue oxygen saturation (StcO2) on mortality in neonates and young infants treated with ECMO. A secondary objective was to evaluate the association between StcO2 and the occurrence of cerebral lesions. Study design This was a prospective study in infants < 3 months of age admitted to a pediatric intensive care unit and requiring ECMO support. Measurements The assessment of cerebral perfusion was made by continuous StcO2 monitoring using near-infrared spectroscopy (NIRS) sensors placed on the two temporo-parietal regions. Neurological lesions were identified by MRI or transfontanellar echography. Results Thirty-four infants <3 months of age were included in the study over a period of 18 months. The ECMO duration was 10±7 days. The survival rate was 50% (17/34 patients), and the proportion of brain injuries was 20% (7/34 patients). The mean StcO2 during ECMO in the non-survivors was reduced in both hemispheres (p = 0.0008 right, p = 0.03 left) compared to the survivors. StcO2 was also reduced in deceased or brain-injured patients compared to the survivors without brain injury (p = 0.002). Conclusion StcO2 appears to be a strong prognostic factor of survival and of the presence of cerebral lesions in young infants during ECMO. PMID:28278259

  11. RELATIONS OF THE CEREBRAL OXYGEN METABOLISM AND THE COGNITIVE FUNCTION AFTER COMBINED DEXMEDETOMIDINE ANESTHESIA OPERATION IN ELDERLY PATIENTS%右美托咪定联合全麻下老年患者术后认知功能与脑氧代谢的关系

    Institute of Scientific and Technical Information of China (English)

    吕安庆; 陈文迪

    2012-01-01

    目的 探讨右美托咪定联合全麻下老年患者术后认知功能与脑氧代谢的关系.方法 选取2009年12月-2011年6月期间在全身麻醉下行手术的老年患者100例,美国麻醉医师协会分级Ⅰ~Ⅲ级.随机分为2组,治疗组和对照组,各50例,采用简易智力状态检查表(mini-mental state examination,MMSE)对比评估2组患者术后6h,1、3d的认知功能.2组于麻醉诱导后即刻(T0 )、麻醉后60min(T1) 和麻醉恢复时(T2) 同步采集桡动脉和颈内静脉球部血样行血气分析,根据血红蛋白(hemoglobin,Hb)、动脉血氧饱和度(arterial oxygen saturation,SaO2)、颈内静脉血氧饱和度(jugular venous oxygen saturation,SjvO2)、动脉血氧分压(arterial partial prussure of oxygen,PaO2) 和颈内静脉血氧分压(jugular venous oxygen partial pressure,PjvO2),计算脑血流量/脑氧代谢率比值(cerebral blood flow to cerebral metabolic rate for oxygen,CBF/CMRO2).结果 手术后6h、1d各组MMSE评分均有不同程度的降低(P<0.05);手术后6h、1d A组MMSE评分明显低于B组(P<0.05);A组T0和T1时,CBF/CMR02异常发生率明显降低,差异有统计学意义(P<0.05); Logistic逐步回归分析显示T1时CBF/CMRO2异常与老年患者术后认知功能障碍的发生有关(β=3.413,P<0.05).结论 全麻下老年患者脑氧代谢异常可能是认知功能障碍的诱导原因之一,右美托咪定可能通过调节脑氧代谢功能来改善术后认知功能.%Objective To investigate the relations of the cerebral oxygen metabolism and the cognitive function after combined dexmedetomidine anesthesia operation in elderly patients. Methods One hundred patients aged over 60 years old were randomly divided into two groups: treatment group ( n = 50 ) and control group ( n = 50 ). A battery of mini - mental state examination ( MMSE ) and neuropsychological tests were administered 6 hours, 1 day and 7 days after surgery. Blood samples were taken from artery and internal jugular

  12. 非心脏大手术老年患者术后认知功能障碍与术中脑氧代谢的关系%Relationship between postoperative cognitive dysfunction after major non-cardiac surgery and intraoperative cerebral oxygen metabolism in elder patients

    Institute of Scientific and Technical Information of China (English)

    蔡一榕; 薛张纲; 朱彪

    2008-01-01

    Objective To investigate the changes of cognitive function after major non-cardiac surgery and the relationship between the postoperative cognitive dysfunction(POCD)and the intraoperative cerebral oxygen metabolism in the elderly.Methods Sixty-four patients(49 male,12 female)aged 65-85 yr undergoing elective major non-cardiac surgery were enrolled in this study.A battery of four neuropsycbological tests was administered 2-3 days before and 7 days after surgery by an experienced psychometrician.A postoperative deficit in any test was defined as a cognitive decline by more than or equal to the preoperative standard deviation of that test in all patients.As long aft any patient showed cognitive decline in two or more tests.this situation was defined as POCD.Blood samples were taken from radial artery and internal jugIIlar vein simultaneously for blood gas analysis immediately (T1) and 2 h (T2) after induction of anesthesia,and just before leaving postanesthesia care unit (T3).The ratio of cerebral blood flow to cerebral oxygen metabolic rate(CBF.CMR02)was calculated.Results Sixty-one patients completed postoperative neuropsychological tests and 10 cases(16.4%)had POCD.Logistic regression analysis showed that the abnormality of CBF/CMR02 during operation was associated with the occurrence of POCD.Conclusion The occurrence of POCD after major non-cardiac surgery is related to the abnormality of cerebral oxygen metabolism during operation.%目的 探讨非心脏大手术老年患者术后认知功能的改变及与术中脑氧代谢的关系.方法 择期非心脏大手术老年患者64例,年龄65~85岁,于术前2~3 d和术后第7天时,分别由心理医师进行一次神经心理测验.在单项测验中术前与术后分值之差≥1个术前分值标准差定为认知功能受损,一个患者在2项或2项以上测验中出现认知功能受损则定为认知功能障碍.于麻醉诱导后即刻、2 h、离开麻醉恢复室时分别同步采集桡动脉和颈

  13. Cerebral blood oxygenation changes induced by visual stimulation in humans

    Science.gov (United States)

    Wenzel, Rudiger; Obrig, Hellmuth; Ruben, Jan; Villringer, Kersten; Thiel, Andreas; Bernarding, Johannes; Dirnagl, Ulrich; Villringer, Arno

    1996-10-01

    We examined local changes of cerebral oxygenation in response to visual stimuli by means of near infrared spectroscopy. A sharply outlined colored moving stimulus which is expected to evoke a broad activation of the striate and prestriate cortex was presented to sixteen healthy subjects. Six of these subjects were also exposed to a colored stationary and a gray stationary stimulus. In two subjects the colored moving stimulus was tested against the colored stationary with an optode position presumably over area V5/MT. As a control condition, subjects performed a simple finger opposition task. Since the calcarine fissure varies greatly with respect to bony landmarks, optodes were positioned individually according to 3D reconstructed magnetic resonance imaging (MRI). Concentration changes in oxyhemoglobin (oxy-Hb) and deoxyhemoglobin (deoxy-Hb) were continuously monitored with a temporal resolution of 1 s, using an NIRO 500. In response to the visual stimulus, the grand average across all sixteen subjects resulted in a significant increase in oxy-Hb of 0.33 +/- 0.09 arbitrary units mirrored by a significant decrease in deoxy-Hb of -0.18 +/- 0.02 arbitrary units, while the motor control condition elicited no significant changes in any parameters. When the near infrared spectroscopy probes were positioned over area V5/MT, the drop of deoxy-Hb associated with the moving stimulus was significantly more pronounced than with the stationary stimulus in both subjects examined. No significant differences between the visual stimuli were observed at the optode position close to the calcarine fissure. The oxygenation changes observed in this study are consistent with the pattern we have reported for motor activation. They are in line with physiological considerations and functional MRI studies relying on blood oxygenation level-dependent contrast.

  14. 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.

  15. Oxygen-sensitive flight metabolism in the dragonfly erythemis simplicicollis

    Science.gov (United States)

    Harrison; Lighton

    1998-06-01

    Insect flight metabolism is completely aerobic, and insect resting metabolism is quite insensitive to atmospheric oxygen level, suggesting a large safety margin in the capacity of the tracheal system to deliver oxygen during flight. We tested the sensitivity of flight initiation and metabolism to atmospheric oxygen level in the libellulid dragonfly Erythemis (Mesothemis) simplicicollis using flow-through respirometric measurements of the rate of CO2 emission (CO2). Flight initiations were unimpaired in atmospheric oxygen levels as low as 10 %. However, flight metabolic rate was affected by ambient oxygen level. Flight CO2 decreased in hypoxic mixtures (5 kPa or 10 kPa oxygen) and increased in hyperoxic atmospheres (30 kPa or 50 kPa oxygen), suggesting that ambient oxygen level influences flight muscle oxygen partial pressure (PO2) and the vigour of flight. These are the first data to show oxygen-limitation of flight metabolism in a free-flying insect. A low safety margin for oxygen delivery during dragonfly flight is consistent with a previous hypothesis that atmospheric hyperoxia facilitated gigantism in Paleozoic protodonates. However, allometric studies of tracheal morphology, and mechanisms and capacity of gas exchange in extant insects are necessary in order to test the hypothesis that the oxygen-sensitivity of aerobic metabolism increases with body size in insects.

  16. 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.

  17. Oxygen-deficient metabolism and corneal edema.

    Science.gov (United States)

    Leung, B K; Bonanno, J A; Radke, C J

    2011-11-01

    Wear of low-oxygen-transmissible soft contact lenses swells the cornea significantly, even during open eye. Although oxygen-deficient corneal edema is well-documented, a self-consistent quantitative prediction based on the underlying metabolic reactions is not available. We present a biochemical description of the human cornea that quantifies hypoxic swelling through the coupled transport of water, salt, and respiratory metabolites. Aerobic and anaerobic consumption of glucose, as well as acidosis and pH buffering, are incorporated in a seven-layer corneal model (anterior chamber, endothelium, stroma, epithelium, postlens tear film, contact lens, and prelens tear film). Corneal swelling is predicted from coupled transport of water, dissolved salts, and especially metabolites, along with membrane-transport resistances at the endothelium and epithelium. At the endothelium, the Na+/K+ - ATPase electrogenic channel actively transports bicarbonate ion from the stroma into the anterior chamber. As captured by the Kedem-Katchalsky membrane-transport formalism, the active bicarbonate-ion flux provides the driving force for corneal fluid pump-out needed to match the leak-in tendency of the stroma. Increased lactate-ion production during hypoxia osmotically lowers the pump-out rate requiring the stroma to swell to higher water content. Concentration profiles are predicted for glucose, water, oxygen, carbon dioxide, and hydronium, lactate, bicarbonate, sodium, and chloride ions, along with electrostatic potential and pressure profiles. Although the active bicarbonate-ion pump at the endothelium drives bicarbonate into the aqueous humor, we find a net flux of bicarbonate ion into the cornea that safeguards against acidosis. For the first time, we predict corneal swelling upon soft-contact-lens wear from fundamental biophysico-chemical principles. We also successfully predict that hypertonic tear alleviates contact-lens-induced edema.

  18. 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

    regression analysis estimated the influence of extra-cerebral oxygenation as exemplified by skin oxygenation (Sskin O2 ) on Sc O2 in 21 healthy subjects exposed to whole-body exercise in hypoxia (Fi O2 = 12%; n = 10) and normoxia (n = 12), whole-body heating, hyperventilation (n = 21), administration...

  19. Cerebral glucose metabolic abnormality in patients with congenital scoliosis

    Energy Technology Data Exchange (ETDEWEB)

    Nam, H. Y.; Seo, G. T.; Lee, J. S.; Kim, S. C.; Kim, I. J.; Kim, Y. K.; Jeon, S. M. [Pusan National University Hospital, Pusan (Korea, Republic of)

    2007-07-01

    A possible association between congenital scoliosis and low mental status has been recognized, but there are no reports describing the mental status or cerebral metabolism in patients with congenital scoliosis in detail. We investigated the mental status using a mini-mental status exam as well as the cerebral glucose metabolism using F-18 fluorodeoxyglucose brain positron emission tomography in 12 patients with congenital scoliosis and compared them with those of 14 age-matched patients with adolescent idiopathic scoliosis. The mean mini-mental status exam score in the congenital scoliosis group was significantly lower than that in the adolescent idiopathic scoliosis group. Group analysis found that various brain areas of patients with congenital scoliosis showed glucose hypometabolisms in the left prefrontal cortex (Brodmann area 10), right orbitofrontal cortex (Brodmann area 11), left dorsolateral prefrontal cortex (Brodmann area 9), left anterior cingulate gyrus (Brodmann area 24) and pulvinar of the left thalamus. From this study, we could find the metabolic abnormalities of brain in patients with congenital scoliosis and suggest the possible role of voxel-based analysis of brain fluorodeoxyglucose positron emission tomography.

  20. Effect of propofol and remifentanil on cerebral perfusion and oxygenation in pigs

    DEFF Research Database (Denmark)

    Mikkelsen, Mai Louise Grandsgaard; Ambrus, Rikard; Miles, James Edward;

    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 onl...

  1. 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;

    1995-01-01

    fraction of the activation-induced excess glucose uptake. These data confirm earlier reports that brain activation can induce resetting of the cerebral oxygen/glucose consumption ratio, and indicate that the resetting persists for a long period after cerebral activation has been terminated and physiologic...

  2. Improved Quantification of Cerebral Vein Oxygenation Using Partial Volume Correction.

    Science.gov (United States)

    Ward, Phillip G D; Fan, Audrey P; Raniga, Parnesh; Barnes, David G; Dowe, David L; Ng, Amanda C L; Egan, Gary F

    2017-01-01

    Purpose: Quantitative susceptibility mapping (QSM) enables cerebral venous characterization and physiological measurements, such as oxygen extraction fraction (OEF). The exquisite sensitivity of QSM to deoxygenated blood makes it possible to image small veins; however partial volume effects must be addressed for accurate quantification. We present a new method, Iterative Cylindrical Fitting (ICF), to estimate voxel-based partial volume effects for susceptibility maps and use it to improve OEF quantification of small veins with diameters between 1.5 and 4 voxels. Materials and Methods: Simulated QSM maps were generated to assess the performance of the ICF method over a range of vein geometries with varying echo times and noise levels. The ICF method was also applied to in vivo human brain data to assess the feasibility and behavior of OEF measurements compared to the maximum intensity voxel (MIV) method. Results: Improved quantification of OEF measurements was achieved for vessels with contrast to noise greater than 3.0 and vein radii greater than 0.75 voxels. The ICF method produced improved quantitative accuracy of OEF measurement compared to the MIV approach (mean OEF error 7.7 vs. 12.4%). The ICF method provided estimates of vein radius (mean error partial volume maps (root mean-squared error partial volume estimates from the ICF method.

  3. Adenosine mediates decreased cerebral metabolic rate and increased cerebral blood flow during acute moderate hypoxia in the near-term fetal sheep.

    Science.gov (United States)

    Blood, Arlin B; Hunter, Christian J; Power, Gordon G

    2003-12-15

    Exposure of the fetal sheep to moderate to severe hypoxic stress results in both increased cortical blood flow and decreased metabolic rate. Using intravenous infusion of 8-cyclopentyl-1,3-dipropylxanthine (DPCPX), a selective adenosine A1 receptor antagonist that is permeable to the blood brain barrier, we examine the role of adenosine A1 receptors in mediating cortical blood flow and metabolic responses to moderate hypoxia. The effects of DPCPX blockade are compared to controls as well as animals receiving intravenous 8-(p-sulfophenyl)-theophylline) (8-SPT), a non-selective adenosine receptor antagonist which has been found to be blood brain barrier impermeable. Laser Doppler flow probes, tissue PO2, and thermocouples were implanted in the cerebral cortices of near-term fetal sheep. Catheters were placed in the brachial artery and sagittal sinus vein for collection of samples for blood gas analysis. Three to seven days later responses to a 30-min period of fetal hypoxemia (arterial PO2 10-12 mmHg) were studied with administration of 8-SPT, DPCPX, or vehicle. Cerebral metabolic rate was determined by calculation of both brain heat production and oxygen consumption. In response to hypoxia, control experiments demonstrated a 42 +/- 7 % decrease in cortical heat production and a 35 +/- 10 % reduction in oxygen consumption. In contrast, DPCPX infusion during hypoxia resulted in no significant change in brain heat production or oxygen consumption, suggesting the adenosine A1 receptor is involved in lowering metabolic rate during hypoxia. The decrease in cerebral metabolic rate was not altered by 8-SPT infusion, suggesting that the response is not mediated by adenosine receptors located outside the blood brain barrier. In response to hypoxia, control experiments demonstrated a 35 +/- 7 % increase in cortical blood flow. DPCPX infusion did not change this increase in cortical blood flow, however 8-SPT infusion attenuated increases in flow, indicating that hypoxic

  4. 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.

  5. Bedside Evaluation of Cerebral Energy Metabolism in Severe Community-Acquired Bacterial Meningitis

    DEFF Research Database (Denmark)

    Rom Poulsen, Frantz; Schulz, Mette; Jacobsen, Anne;

    2015-01-01

    BACKGROUND: Mortality and morbidity have remained high in bacterial meningitis. Impairment of cerebral energy metabolism probably contributes to unfavorable outcome. Intracerebral microdialysis is routinely used to monitor cerebral energy metabolism, and recent experimental studies indicate...... that this technique may separate ischemia and non-ischemic mitochondrial dysfunction. The present study is a retrospective interpretation of biochemical data obtained in a series of patients with severe community-acquired meningitis. METHODS: Cerebral energy metabolism was monitored in 15 patients with severe...... community-acquired meningitis utilizing intracerebral microdialysis and bedside biochemical analysis. According to previous studies, cerebral ischemia was defined as lactate/pyruvate (LP) ratio >30 with intracerebral pyruvate level

  6. Cerebral blood flow response to functional activation

    DEFF Research Database (Denmark)

    Paulson, Olaf B; Hasselbalch, Steen G; Rostrup, Egill

    2010-01-01

    Cerebral blood flow (CBF) and cerebral metabolic rate are normally coupled, that is an increase in metabolic demand will lead to an increase in flow. However, during functional activation, CBF and glucose metabolism remain coupled as they increase in proportion, whereas oxygen metabolism only...

  7. Cerebral blood flow and oxygenation in infants after birth asphyxia. Clinically useful information?

    DEFF Research Database (Denmark)

    Greisen, Gorm

    2014-01-01

    The term 'luxury perfusion' was coined nearly 50 years ago after observation of bright-red blood in the cerebral veins of adults with various brain pathologies. The bright-red blood represents decreased oxygen extraction and hence the perfusion is 'luxurious' compared to oxygen needs. Gradual loss...

  8. Imaging cerebral 2-ketoisocaproate metabolism with hyperpolarized (13)C Magnetic Resonance Spectroscopic Imaging

    DEFF Research Database (Denmark)

    Butt, Sadia Asghar; Søgaard, Lise Vejby-Christensen; Magnusson, Peter O.;

    2012-01-01

    The branched chain amino acid transaminase (BCAT) has an important role in nitrogen shuttling and glutamate metabolism in the brain. The purpose of this study was to describe the cerebral distribution and metabolism of hyperpolarized 2-keto[1-(13)C]isocaproate (KIC) in the normal rat using magnetic...... resonance modalities. Hyperpolarized KIC is metabolized to [1-(13)C]leucine (leucine) by BCAT. The results show that KIC and its metabolic product, leucine, are present at imageable quantities 20 seconds after end of KIC administration throughout the brain. Further, significantly higher metabolism...... was observed in hippocampal regions compared with the muscle tissue. In conclusion, the cerebral metabolism of hyperpolarized KIC is imaged and hyperpolarized KIC may be a promising substrate for evaluation of cerebral BCAT activity in conjunction with neurodegenerative disease.Journal of Cerebral Blood Flow...

  9. Cerebral hemodynamics and metabolism in patients with moyamoya disease not demonstrating either cerebral infarct or hemorrhage on MRI

    Energy Technology Data Exchange (ETDEWEB)

    Kuwabara, Yasuo; Ichiya, Yuichi; Sasaki, Masayuki; Akashi, Yuko; Yoshida, Tsuyoshi; Fukumura, Toshimitsu; Masuda, Kouji; Matsushima, Toshio; Fukui, Masashi [Kyushu Univ., Fukuoka (Japan). Faculty of Medicine

    1995-12-01

    We evaluated the cerebral hemodynamics and metabolism in moyamoya patients who did not demonstrate either cerebral infarct or hemorrhage on MRI. The subjects consisted of 5 patients with moyamoya disease (4 females and one male, aged from 15 to 40 ears). The CBF, OEF and CMRO{sub 2} of the moyamoya patients did not differ from those of the normal control subjects. The CBV did increase significantly in the cerebral cortices and striatum, but not in the cerebellum. The TT was also significantly prolonged in the frontal and parietal regions. The cerebrovascular CO{sub 2} response was markedly impaired in the frontal, temporal and parietal cortices. However, it was relatively preserved in the occipital cortex, thalamus and cerebellum. Thus, the cerebral hemodynamic reserve capacity decreased even in the moyamoya patients not demonstrating either cerebral infarct or hemorrhage on MRI, and it should be considered in the management of these patients. (author).

  10. [Evaluation of cerebral oxygenation in newborns with prematurity apnea: new frequency domain NIR oximeter].

    Science.gov (United States)

    Pratesi, S; Donzelli, G

    2000-01-01

    Near infrared spectroscopy (NIRS) is a non invasive, portable, safe technique for monitoring cerebral oxygenation and haemodynamics. A new frequency-domain tissue oximeter based on a multi-distance measurement protocol is presented. The effects of apneic episodes on cerebral and peripheral arterial oxygen saturation (SatO2) in preterm newborns, as monitored by NIRS and by pulse oximetry, are reported. The study population consist of 5 preterms (26 to 30 weeks of gestational age), in the second week of postnatal age, affected by apnea of prematurity. NIRS and pulse oximetric measurements were made contemporarily for a 40-minutes period for each infant. All monitorized apneic events were associated with bradicardia, and resolved spontaneously or after tactile stimulation. As results: a) there was always cerebral deoxygenation in association with apneic events, b) the mean SatO2 as measured by NIRS was slightly lower than the pulse oximeter readings, c) cerebral SatO2 decreased faster and the absolute value of the cerebral SaO2 decrease was greater than that measured peripherally (mean value of 27 versus 13%), d) increases of cerebral deoxyhemoglobin and total hemoglobin and a decrease of oxyhemoglobin were also observed. These preliminary results show that peripheral oxygen saturation measurements as measured by pulse oximetry could not always reflect brain oxygenation.

  11. Cyclooxygenase-derived vasoconstriction restrains hypoxia-mediated cerebral vasodilation in young adults with metabolic syndrome.

    Science.gov (United States)

    Harrell, John W; Schrage, William G

    2014-01-15

    Poor cerebrovascular function in metabolic syndrome (MetSyn) likely contributes to elevated risk of cerebrovascular disease in this growing clinical population. Younger MetSyn adults without clinical evidence of cerebrovascular disease exhibit preserved hypercapnic vasodilation yet markedly impaired hypoxic vasodilation, but the mechanisms behind reduced hypoxic vasodilation are unknown. Based on data from rats, we tested the hypothesis that younger adults with MetSyn exhibit reduced cerebral hypoxic vasodilation due to loss of vasodilating prostaglandins. Middle cerebral artery velocity (MCAv) was measured with transcranial Doppler ultrasound in adults with MetSyn (n = 13, 33 ± 3 yr) and healthy controls (n = 15, 31 ± 2 yr). Isocapnic hypoxia was induced by titrating inspired oxygen to lower arterial saturation to 90% and 80% for 5 min each. Separately, hypercapnia was induced by increasing end-tidal CO2 10 mmHg above baseline levels. Cyclooxygenase inhibition (100 mg indomethacin) was conducted in a randomized double-blind, placebo controlled design. MCAv was normalized for group differences in blood pressure (healthy: 89 ± 2 mmHg vs. MetSyn: 102 ± 2 mmHg) as cerebrovascular conductance index (CVCi), and used to assess cerebral vasodilation. Hypoxia increased CVCi in both groups; however, vasodilation was ∼55% lower in MetSyn at SpO2 = 80% (P vasodilation in healthy controls, and unexpectedly increased dilation in MetSyn (P vasodilation was similar between groups, as was the decrease in vasodilation with indomethacin. These data indicate increased production of vasoconstrictor prostaglandins restrains hypoxic cerebral vasodilation in MetSyn, preventing them from responding appropriately to this important physiological stressor.

  12. 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.

  13. Oxygen, a key factor regulating cell behaviour during neurogenesis and cerebral diseases

    Directory of Open Access Journals (Sweden)

    Kuan eZhang

    2011-04-01

    Full Text Available Oxygen is vital to maintain the normal functions of alomost all the organs, especially for brain which is one of the heaviest oxygen consumers in the body. The important roles of oxygen on the brain are not only reflected in the development, but also showed in the pathological processes of many cerebral diseases. In the current review, we summarized the oxygen levels in brain tissues tested by real-time measurements during the embryonic and adult neurogenesis, the cerebral diseases or in the hyperbaric/hypobaric oxygen environment. Oxygen concentration is low in fetal brain (0.01%- 1% and in adult brain (1.5%-7%, decreased during stroke, and increased in hyperbaric oxygen environment. In addition, we reviewed the effects of oxygen tensions on the behaviors of neural stem cells (NSCs in vitro cultures at different oxygen concentration (2%-20% and in vivo niche during different pathological states and in hyperbaric/hypobaric oxygen environment. Moderate hypoxia (3%-10% is known can promote the proliferation of NSCs and enhance the differentiation of NSCs into the TH-positive neurons. Next, we briefly presented the oxygen-sensitive molecular mechanisms regulating NSCs proliferation and differentiation recently found including the Notch, BMP and Wnt pathways. Finally, the future perspectives about the roles of oxygen on brain and NSCs were given.

  14. Prone position is associated with mild cerebral oxygen desaturation in elderly surgical patients.

    Directory of Open Access Journals (Sweden)

    Stacie Deiner

    Full Text Available PURPOSE: A variety of hemodynamic and respiratory alterations accompany patients in the prone position; however the effect of the prone position on intraoperative cerebral saturation has not been studied. We sought to examine whether the incidence of cerebral oxygen desaturation in elderly patients (≥68 years of age undergoing spine surgery in the prone position was more common than patients undergoing major surgery in the supine position. METHODS: We performed a retrospective cohort study of 205 patients; 63 patients underwent surgery in the prone position and 142 in the supine position. Patients were evaluated for cerebral desaturation with bilateral cerebral oximetry. The primary predictor was position, secondary were: length of the surgery, incidence and duration of cerebral desaturation episodes at several thresholds, average time of Bispectral index below threshold of 45 in minutes, average electroencephalogram suppression ratio >0, amount of blood transfused, and the incidence of hypotension and hypertension. RESULTS: Elderly spine surgery patients in the prone position were more than twice as likely to experience mild cerebral desaturation as patients in the supine position. Patients in the prone position had longer surgeries; however cerebral desaturation in the prone position was significantly more common even when adjusted for surgery time and the occurrence of intraoperative hypotension. CONCLUSION: Cerebral desaturation is related to the prone position in elderly surgery patients. Future studies are necessary to determine whether this translates to a higher incidence of postoperative cognitive dysfunction and delirium.

  15. Global cerebral blood flow and metabolism during acute hyperketonemia in the awake and anesthetized rat

    DEFF Research Database (Denmark)

    Linde, Rasmus; Hasselbalch, Steen G.; Topp, Simon;

    2006-01-01

    In the human setting, it has been shown that acute increase in the concentration of ketone bodies by infusion of beta-hydroxybutyrate increased the cerebral blood flow (CBF) without affecting the overall cerebral metabolic activity. The mechanism by which this effect of ketone bodies was mediated...

  16. Cerebral oxygenation and haemodynamic effects induced by nimodipine in healthy subjects.

    Science.gov (United States)

    Canova, Daniela; Roatta, Silvestro; Micieli, Giuseppe; Bosone, Daniele

    2012-01-01

    The cerebrovascular effects of nimodipine are still poorly understood even in the healthy condition; in particular, its effects on tissue oxygenation have never been investigated. The aim of the present study was to investigate changes in cerebral oxygenation and blood volume upon oral administration of nimodipine (90 mg) in the healthy condition. In eight subjects, changes in cerebral tissue oxygenation and blood volume were determined simultaneously with changes in blood velocity of the middle cerebral artery (VMCA) by using, respectively, near infrared spectroscopy (NIRS) and transcranial Doppler ultrasonography (TCD). The subjects also underwent noninvasive assessment of arterial blood pressure (ABP) and end-tidal CO2. TCD and NIRS CO2 reactivity indices were al-so extracted. Nimodipine significantly reduced ABP (11±13%) and increased heart rate, as well as NIRS oxygenation(6.0±4.8%) and blood volume indices (9.4±10.1%), while V(MCA) was not significantly decreased (2.0±3.5%). Nimodipine slightly but significantly reduced the V(MCA) response to changes in pCO2 whereas the CO2 reactivity of NIRS parameters was improved. The observed changes in cerebral tissue oxygenation and blood volume indicate nimodipine-induced cerebrovascular dilation and increased perfusion, while the effect on V(MCA)possibly results from dilation of the insonated artery. The present results cast doubt on the putative nimodipine-induced impairment of CO2 reactivity.

  17. Aerobic fitness influences cerebral oxygenation response to maximal exercise in healthy subjects.

    Science.gov (United States)

    Oussaidene, Kahina; Prieur, Fabrice; Tagougui, Semah; Abaidia, Abdelbasset; Matran, Regis; Mucci, Patrick

    2015-01-01

    The study examined whether the aerobic fitness level modifies the cerebral oxygenation response to incremental ramp exercise, and more specifically the decline in cerebral oxygenation from heavy exercise up to maximal intensities. 11 untrained (VO2max 47.3±4.0 mL min(-1) kg(-1)) and 13 endurance-trained (VO2max 61.2±8.0 mL min(-1) kg(-1)) healthy men performed a maximal ramp cycle exercise. Left prefrontal cortex oxygenation (ΔHbO2) was monitored by near-infrared spectroscopy. A cerebral oxygenation threshold decline (ThCOx) during exercise was determined. ThCox occurred in all subjects but for higher VO2 (mL min(-1) kg(-1)) in endurance-trained than in untrained subjects (Pexercise intensity corresponding to ThCOx, ΔHbO2 was higher in endurance-trained than in untrained subjects (Pexercise intensities in endurance-trained in relation with their higher VO2max than untrained men. These results demonstrated that aerobic fitness influences cerebral oxygenation during exercise.

  18. 尼卡地平与硝酸甘油控制性降压对颅内动脉瘤夹闭术患者脑氧代谢的影响%Effects of nicardipine and nitroglycerin on cerebral oxygen metabolism during controlled hypotension in intracranial aneurysm clipping surgery

    Institute of Scientific and Technical Information of China (English)

    韩明明; 赵国庆; 苏毅; 高明

    2012-01-01

    Objective To compare the effects of controlled hypotension respectively with nicardipinc and nitroglycer-in on cerebral oxygen metabolism in intracranial ancurysm clipping surgery. Methods 40 patients, involved in this randomized, controlled and double-blind trail, undergoing intracranial ancurysm clipping surgery were devided into Nicar-dipinc( I ) Group and Nitroglycerine (Ⅱ ) Group with 20 cases each. Control hypotension at the moment of cutting dura-mater. Blood gas analyses were performed at the time of T0、Ti、T2 and T3 respectively corresponding to the moment of cutting duramatcr,ancurysm isolation completed, ancurysm clipping done and 20 min after controlled hypotension, by taking samples from radical arteries and jugular vein bulbs. Record the values of PaO2 ,PjvO2 ,SaO2 ,SjvO2 ,Hab,Hjvb and calculate the values of Da-jvO2 and COER. Rsecults Blood pressures were kept at a desirable level without significant difference (P>0. 05). Heart rates in both groups increased obviously (P0. 05) during controlled hypotension. Compared with T0 and T3 , the values of SjvO2 at T1 and T2 increased signifi-cantly(P0. 05 ). Compared with group Ⅱ ,thc values of SjvO2 at T2 and T3 were significantly higher (P<0. 05) whereas the values of Da-jvO2 and COER were significantly lower (P<0. 05) in group I . Conclusion Both nitroglyc-crin and nicardipinc can be safely used for controlling hypotension in intracranial ancurysm clipping surgery. But the later can effectively decrease cerebral oxygen metabolism and improve cerebral oxygenation which is superior to the former in terms of cerebral protection.%目的 对比尼卡地平与硝酸甘油控制性降压对颅内动脉瘤夹闭术患者脑氧代谢的影响.方法 采取随机、对照、双盲的方法将40例行颅内动脉瘤夹闭术的患者分成尼卡地平(Ⅰ)组和硝酸甘油(Ⅱ)组,每组20人.打开硬脑膜行控制性降压,并于打开硬脑膜即刻(T0)、瘤体分离结束(T1)、夹闭完毕(T2)、

  19. Effects of sedation induced with dexmedetomidine versus propofol on intracranial pressure and cerebral oxygen metabolism in patients with permissive hypercapnia%右美托咪啶与异丙酚镇静下允许性高碳酸血症患者颅内压及脑氧代谢的比较

    Institute of Scientific and Technical Information of China (English)

    王丽萍; 陈国忠

    2011-01-01

    Objective To compare the effects of sedation induced with dexmedetomidine and propofol on intracranial pressure and cerebral oxygen metabolism in patients with permissive hypercapnia. Methods Twentyfour patients with acute respiratory distress syndrome (ARDS) were randomly divided into 2 groups ( n = 12 each) :dexmedetomidine group (group D) and propofol group (group P) . Their APACHE Ⅱ scores were 11-18. The patients were mechanically ventilated (VT 5-7 ml/kg, RR 12-17 bpm, PEEP 6-10 cm H2O, FiO2 40-60%). PaCO2 was maintained at 50-65 mm Hg. Radial artery was cannulated for direct BP monitoring and blood sampling. Right internal jugular vein was cannulated and the catheter was advanced cephalad until jugular bulb. Continuous infusion of dexmedetomidine was started at 0.5 μg· kg-1· h-1 and TCI of propofol was started at target plasma concentration (Cp) of 0.4 μg/ml. The infusion of both drugs was gradually increased until Ramsay score (1= fully awake, 6 =asleep, unresponsive to loud verbal stimulus) reached 3,4,5. Transcranial Doppler monitoring was used to determine cerebral blood flow velocity (CBFV), pulsatility index (PI) and resistance index (RI) before administration of dexmedetomidine and propofol (T0 ) and at 30 min after the 3 levels of sedation were reached (T1-3) . Meanwhile blood samples were taken from radial artery and jugular bulb for blood gas analyses. Cerebral O2 metabolic rate (CMRO2), cerebral A-V O2 content differences (Da-jvO2) and cerebral O2 extraction rate (CERO2) were calculated .ResultsCBFV, PI, RI and CMRO2 were significantly decreased at T1-3 as compared with the baseline values at T0 in both groups. CBFV was positively correlated with CMRO2 in both group D (r = 0.80) and group P ( r = 0.76) . CBFV, PI and RI were significantly lower at T1-3 in group D than in group P. There was no significant change in Da-jvO2 and CERO2 at T1-3 as compared with the baseline values at T0 in both groups. Conclusion At different sedation levels

  20. Reduction in Cerebral Oxygenation due to Patent Ductus Arteriosus Is Pronounced in Small-for-Gestational-Age Neonates

    NARCIS (Netherlands)

    Cohen, Emily; Dix, Laura; Baerts, Willem; Alderliesten, Thomas; Lemmers, Petra; van Bel, Frank

    2016-01-01

    BACKGROUND: A haemodynamically significant patent ductus arteriosus (hsPDA) reduces cerebral oxygenation in appropriate-for-gestational-age (AGA) preterm neonates. Reduced cerebral oxygenation has been associated with brain injury. Preterm small-for-gestational-age (SGA) neonates show higher cerebra

  1. 一氧化碳中毒迟发脑病患者高压氧综合治疗前后脑葡萄糖代谢的变化%Change of cerebral metabolism rate of glucose in patient of delayed neuropsychologlcal sequelae after CO poisoning following combining hyperbaric oxygen treatment

    Institute of Scientific and Technical Information of China (English)

    高宇; 高春锦; 王铁; 葛环; 武连华; 赵立明; 宋振国

    2008-01-01

    Objective To estimate the effect of hyperbaric oxygen treatment on cerebral metabolism rate of glucose(CMRglc)in patients with delayed neuropsychological sequelae after CO poisoning(DNS).Methods Thirty cases of DNS were received 18F-FDGPET examination before hyperbaric oxygen treatment (HBOT)and after 40th HBOT respectively.At the same time 17 healthy examiner were also received 18F-FDG PET examination.Radioactive counts in bilateral frontal lobe,parietal lobe,temporal lobe,occipital lobe and ipsilateral cerebellum unit area were recorded,and the radio of radioactive counts were measured and used to evaluate PET study as semi-quantitative parameter.Results The CMRglc of DNS patient decreased in bilateral frontal lobe,parietal lobe,temporal lobe and occipital lobe before HBOT(P<0.05).After HBOT,there were obvious improvement of CMRglc in bilateral parietal lobe,occipital lobe and left side temporal lobe(P<0.05)and no differences in bilateral frontal lobe and right side temporal lobe.Conclusions The CMRglc decreased on the early phase of DNS.Combining hyperbaric oxygen treatment can improve CMRglc and cerebral function.%目的 观察一氧化碳中毒迟发脑病高压氧综合治疗前后患者脑葡萄糖代谢的变化,探讨高压氧综合治疗的作用.方法 一氧化碳中毒迟发脑病(DNS)患者30例(DNS组),高压氧综合治疗前及治疗40次后分别接受18F标记的脱氧葡萄糖正电子发射断层扫描(18F-FDG PET)检查,同时对17例年龄匹配的健康体检者(对照组)进行18F-FDG PET检查.记录DNS组与对照组的双侧额叶、顶叶、颞叶、枕叶与同侧小脑单位面积的放射性计数;计算双侧额叶、顶叶、颞叶、枕叶与同侧小脑单位面积放射性计数的比值,以此比值作为PET研究的半定量观察指标.结果 DNS组高压氧综合治疗前双侧的额/小脑、顶/小脑、颞/小脑、枕/1h脑的比值明显低于对照组(P<0.05);高压氧综合治疗40次后,双侧的顶/小脑、

  2. The Role of Exercise – Rehabilitation on Energy Cost and Metabolic Efficiency in Dipelegic Spastic Cerebral Palsy Children

    Directory of Open Access Journals (Sweden)

    M. Izadi

    2005-07-01

    Full Text Available Introduction & Objective: The aim of this study was to compare the resting energy expenditure and metabolic efficiency before and after of aerobic exercise in spastic cerebral palsy children (mean age of 11 years and also to compare with those of normal children. Materials & Methods : Fifteen dipelegia spastic cerebral palsy children (experimental group participated in exercise–rehabilitation program by voluntarily and the peers eighteen able body children(control group were selected randomly. The experimental group(cp performed rehabilitation program for 3 months,3 session in week with work intensity(%HRR=462.5equal to144bpm of heart rate. The values were measured on tantory cycle ergometer according to Macmaster protocol.Results: Rest and exercise heart rate and exercise intensity(%HRR in patients decreased after rehabilitation program(P<0.05. The resting energy expenditure was similar in cp and normal groups. The rate of oxygen cost of patients decreased in post test(P<0.05 that showed increasing in metabolic efficiency.Conclusion: cerebral palsy children have greater exercise energy cost and lower cardiovascular fitness than normal children and exercise–rehabilitation leads to enhance of metabolic efficiency in this patients that is remarkable from clinical perception.

  3. Effect of artificial hyperventilation on cerebral oxygenation and metabolism under controlled hypotention during intracranial aneurysm surgery%过度通气对控制性降压下颅内动脉瘤夹闭术中脑氧代谢的影响

    Institute of Scientific and Technical Information of China (English)

    刘永哲; 高明龙; 潘宁玲

    2011-01-01

    Objective To investigate the effect ot various degree of artificial byperventilation on cerebral oxygenation and metabolism under controlled hypotention during intracranial aneurysm surgery. Methods thirtysix patients (ASA Ⅰ - Ⅱ ) scheduled for intracranial aneurysm surgery were divided into there groups according to PaCO2: hypotention and PaCO2 (40 ± 2) mmHg (group A), hypotention and PaCO2 (35 ± 2) mmHg (group B)and hypotention and PaCO2 (30 ± 2) mmHg (group C). Arterial and jugular venous blood samples were taken before hypotention (T0), after hypotention for 15 min (T1), artificial ventilation for 15 min (T2), and at the end of hypotention and artificail ventilation (T3). The arterial oxygen content (CaO2), jugular venous oxgen conent (CjvO2), arterial and jugular bulb venous O2 content difference (Da-jvO2) and cerebral oxygen extraction rate (CERO2) were calculated. Results Compared with T0, MAP has significantly decreased at T1 and T2 (P <0.05) and there was no difference at T3 between groups (P>0.05). Compared with T0, CaO2 bas no difference at all points in group C (P > 0.05), CjvO2 decreased significantly at T2 in group C (P < 0.05), Da-jvO2 and CERO2 have increased significantly at T2 in group C (P < 0.05). Conclusion Keeping PaCO2 (30 ± 2)mmHg leads to disorder of cerebral oxygen metabolism and it is safe to keep PaCO2 (35 ± 2) mmHg during intracranial aneurysm surgery.%目的:研究过度通气对控制性降压下颅内动脉瘤夹闭术中脑氧代谢的影响.方法:择取颅内动脉瘤患者36例,ASAⅠ~Ⅱ级,随机分为正常通气组(A组,PaCO2 35 ~ 40 mmHg)、轻度通气组(B组,PaCO2 30 ~ 35 mmHg)和中度通气组(C组,PaCO2 25 ~ 30 mmHg).各组应用硝酸甘油控制性降压,降压幅度在基础值的20% ~ 25%,在降压达到目标值15 min后进行过度通气.各组于降压前(T0)、降压达到目标血压15 min后(T1)、过度通气使PaCO2达到各组预定值15 min后(T2)、MAP恢复且PaCO2

  4. Decreased cerebral glucose metabolism associated with mental deterioration in multi-infarct dementia

    Energy Technology Data Exchange (ETDEWEB)

    Meguro, K. (Tohoku Univ. School of Medicine (Japan). Dept. of Geriatric Medicine Miyama Hospital (Japan)); Doi, C. (Tohoku Univ. School of Literature (Japan). Dept. of Psychology); Yamaguchi, T.; Sasaki, H. (Tohoku Univ. School of Medicine (Japan). Dept. of Geriatric Medicine); Matsui, H.; Yamada, K. (Tohoku Univ. (Japan). Research Inst. for Tuberculosis and Cancer); Kinomura, S. (Miyama Hospital (Japan) Tohoku Univ. (Japan). Research Inst. for Tuberculosis and Cancer); Itoh, M. (Tohoku Univ. School of Medicine (Japan). Cyclotron Radioisotope Center)

    1991-08-01

    Cerebral glucose metabolism of 18 patients with multi-infarct dementia (MID) and 10 age-matched normal subjects were examined with positron emission tomography and the {sup 18}-F-fluoro-deoxy-glucose technique. MID patients had significantly lower glucose metabolsim in all the grey matter regions measured and were also characterized by more individuality in metabolic pattern. MID patients were also evaluated as to intelligence quotient (IQ). A positive correlation between IQ as shown by the Tanaka-Binet test and glucose metabolism for the entire grey matter was found. The clinical applicability of this test for predicting cerebral metabolism is discussed. (orig.).

  5. Effect of propofol and remifentanil on cerebral perfusion and oxygenation in pigs

    DEFF Research Database (Denmark)

    Mikkelsen, Mai Louise Grandsgaard; Ambrus, Rikard; Miles, James Edward

    2016-01-01

    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......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...... 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...

  6. 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...... 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...... at higher workloads in T2DM patients and their work capacity and increase in cardiac output were only ~80% of that established in the control subjects. CBF and cerebral oxygenation were reduced during exercise in T2DM patients (P

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

    DEFF Research Database (Denmark)

    Nielsen, Henning B

    2014-01-01

    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...

  8. Effects of midazolam and morphine on cerebral oxygenation and hemodynamics in ventilated premature 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: Midazolam sedation and morphine analgesia are commonly used in ventilated premature infants. OBJECTIVES: To evaluate the effects of midazolam versus morphine infusion on cerebral oxygenation and hemodynamics in ventilated premature infants. METHODS: 11 patients (GA 26.6-33.0 weeks, BW 78

  9. 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 th...

  10. 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.

  11. Cerebral metabolism of ammonia and amino acids in patients with fulminant hepatic failure

    DEFF Research Database (Denmark)

    Strauss, Gitte Irene; Knudsen, Karen Birgitte Moos; Kondrup, Jens;

    2001-01-01

    BACKGROUND & AIMS: High circulating levels of ammonia have been suggested to be involved in the development of cerebral edema and herniation in fulminant hepatic failure (FHF). The aim of this study was to measure cerebral metabolism of ammonia and amino acids, with special emphasis on glutamine...... metabolism. METHODS: The study consisted of patients with FHF (n = 16) or cirrhosis (n = 5), and healthy subjects (n = 8). Cerebral blood flow was measured by the 133Xe washout technique. Blood samples for determination of ammonia and amino acids were drawn simultaneously from the radial artery...... and the internal jugular bulb. RESULTS: A net cerebral ammonia uptake was only found in patients with FHF (1.62 +/- 0.79 micromol x 100 g(-1) x min(-1)). The cerebral glutamine efflux was higher in patients with FHF than in the healthy subjects and cirrhotics, -6.11 +/- 5.19 vs. -1.93 +/- 1.17 and -1.50 +/- 0...

  12. A quantitative study of oxygen as a metabolic regulator

    Science.gov (United States)

    Radhakrishnan, Krishnan; LaManna, Joseph C.; Cabrera, Marco E.

    2003-01-01

    An acute reduction in oxygen delivery to a tissue is associated with metabolic changes aimed at maintaining ATP homeostasis. However, given the complexity of the human bioenergetic system, it is difficult to determine quantitatively how cellular metabolic processes interact to maintain ATP homeostasis during stress (e.g., hypoxia, ischemia, and exercise). In particular, we are interested in determining mechanisms relating cellular oxygen concentration to observed metabolic responses at the cellular, tissue, organ, and whole body levels and in quantifying how changes in tissue oxygen availability affect the pathways of ATP synthesis and the metabolites that control these pathways. In this study, we extend a previously developed mathematical model of human bioenergetics, to provide a physicochemical framework that permits quantitative understanding of oxygen as a metabolic regulator. Specifically, the enhancement--sensitivity analysis--permits studying the effects of variations in tissue oxygenation and parameters controlling cellular respiration on glycolysis, lactate production, and pyruvate oxidation. The analysis can distinguish between parameters that must be determined accurately and those that require less precision, based on their effects on model predictions. This capability may prove to be important in optimizing experimental design, thus reducing use of animals.

  13. Effect of Oxygen on Lactose Metabolism in Lactic Streptococci

    OpenAIRE

    Smart, John B.; Thomas, Terence D.

    1987-01-01

    Three strains of Streptococcus lactis, two of Streptococcus cremoris, and one of Streptococcus thermophilus metabolized oxygen in the presence of added carbohydrate primarily via a closely coupled NADH oxidase/NADH peroxidase system. No buildup of the toxic intermediate H2O2 was detected with the three S. lactis strains. All six strains contained significant superoxide dismutase activity and are clearly aerotolerant. Lactose- or glucose-driven oxygen consumption was biphasic, with a rapid ini...

  14. 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

  15. Cerebral blood flow and metabolism in adults with acute bacterial meningitis

    DEFF Research Database (Denmark)

    Møller, Kirsten

    2007-01-01

    The intense intrathecal inflammation observed in acute bacterial meningitis (ABM) is associated with pronounced changes in cerebral blood flow (CBF) and metabolism. In seven substudies, CBF and metabolism were measured in adults with ABM as well as healthy volunteers during various interventions...

  16. 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.

  17. The role of blood flow distribution in the regulation of cerebral oxygen availability in fetal growth restriction.

    Science.gov (United States)

    Luria, Oded; Bar, Jacob; Kovo, Michal; Malinger, Gustavo; Golan, Abraham; Barnea, Ofer

    2012-04-01

    Fetal growth restriction (FGR) elicits hemodynamic compensatory mechanisms in the fetal circulation. These mechanisms are complex and their effect on the cerebral oxygen availability is not fully understood. To quantify the contribution of each compensatory mechanism to the fetal cerebral oxygen availability, a mathematical model of the fetal circulation was developed. The model was based on cardiac-output distribution in the fetal circulation. The compensatory mechanisms of FGR were simulated and their effects on cerebral oxygen availability were analyzed. The mathematical analysis included the effects of cerebral vasodilation, placental resistance to blood flow, degree of blood shunting by the ductus venosus and the effect of maternal-originated placental insufficiency. The model indicated a unimodal dependency between placental blood flow and cerebral oxygen availability. Optimal cerebral oxygen availability was achieved when the placental blood flow was mildly reduced compared to the normal flow. This optimal ratio was found to increase as the hypoxic state of FGR worsens. The model indicated that cerebral oxygen availability is increasingly dependent on the cardiac output distribution as the fetus gains weight.

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

    Directory of Open Access Journals (Sweden)

    Henning Bay Nielsen

    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.

  19. Correlation of brain tissue oxygen tension with cerebral near-infrared spectroscopy and mixed venous oxygen saturation during extracorporeal membrane oxygenation.

    Science.gov (United States)

    Tyree, Kreangkai; Tyree, Melissa; DiGeronimo, Robert

    2009-09-01

    The aim of this prospective, animal study was to compare brain tissue oxygen tension (PbtO(2)) with cerebral near infrared spectroscopy (NIRS) and mixed venous oxygen saturation (SVO(2)) during venoarterial extracorporeal membrane oxygenation (VA ECMO) in a porcine model. This was accomplished using twelve immature piglets with surgically implanted catheters placed in the superficial cerebral cortex to measure brain PbtO(2) and microdialysis metabolites. The NIRS sensor was placed overlying the forehead to measure cerebral regional saturation index (rSO(2)i) while SVO(2) was measured directly from the ECMO circuit. Animals were placed on VA ECMO followed by an initial period of stabilization, after which they were subjected to graded hypoxia and recovery. Our results revealed that rSO(2)i and SVO(2) correlated only marginally with PbtO(2) (R(2)=0.32 and R(2)=0.26, respectively) while the correlation between rSO(2)i and SVO( 2) was significantly stronger (R(2)=0.59). Cerebral metabolites and rSO(2)i were significantly altered during attenuation of PbtO( 2), p<0.05). A subset of animals, following exposure to hypoxia, experienced markedly delayed recovery of both rSO(2)i and PbtO( 2) despite rapid normalization of SVO(2). Upon further analysis, these animals had significantly lower blood pressure (p=0.001), lower serum pH (p=0.01), and higher serum lactate (p=0.02). Additionally, in this subgroup, rSO(2)i correlated better with PbtO(2) (R(2)=0.76). These findings suggest that, in our ECMO model, rSO(2)i and SVO( 2) correlate reasonably well with each other, but not necessarily with brain PbtO(2) and that NIRS-derived rSO(2)i may more accurately reflect cerebral tissue hypoxia in sicker animals.

  20. The impact of oxygen on metabolic evolution: a chemoinformatic investigation.

    Directory of Open Access Journals (Sweden)

    Ying-Ying Jiang

    Full Text Available The appearance of planetary oxygen likely transformed the chemical and biochemical makeup of life and probably triggered episodes of organismal diversification. Here we use chemoinformatic methods to explore the impact of the rise of oxygen on metabolic evolution. We undertake a comprehensive comparative analysis of structures, chemical properties and chemical reactions of anaerobic and aerobic metabolites. The results indicate that aerobic metabolism has expanded the structural and chemical space of metabolites considerably, including the appearance of 130 novel molecular scaffolds. The molecular functions of these metabolites are mainly associated with derived aspects of cellular life, such as signal transfer, defense against biotic factors, and protection of organisms from oxidation. Moreover, aerobic metabolites are more hydrophobic and rigid than anaerobic compounds, suggesting they are better fit to modulate membrane functions and to serve as transmembrane signaling factors. Since higher organisms depend largely on sophisticated membrane-enabled functions and intercellular signaling systems, the metabolic developments brought about by oxygen benefit the diversity of cellular makeup and the complexity of cellular organization as well. These findings enhance our understanding of the molecular link between oxygen and evolution. They also show the significance of chemoinformatics in addressing basic biological questions.

  1. Cerebral regional oxygen saturation monitoring in pediatric malfunctioning shunt patients☆,☆☆,★

    Science.gov (United States)

    Abramo, Thomas J.; Zhou, Chuan; Estrada, Cristina; Drayna, Patrick C.; Locklair, Matthew R.; Miller, Renee; Pearson, Matthew; Tulipan, Noel; Arnold, Donald H.

    2014-01-01

    Background Shunt malfunction produces increased intracranial pressure causing decreased cerebral regional perfusion and tissue O2sat. Cerebral regional oxygen saturation (rSO2) by near-infrared spectroscopy represents tissue perfusion and oxygen saturation. Cerebral rSO2 is used to detect cerebral ischemia in pediatric clinical settings. Objective The objective of the study was to determine the reliability of cerebral rSO2 in pediatric malfunctioning shunt. Methods A prospective observational study of pediatric patients presented to the pediatric emergency department was conducted. Confirmed malfunctioning shunt subjects had cerebral rSO2 monitoring. Results A total of 131 malfunctioning shunt subjects had cerebral rSO2 monitoring. Patient's central trend and intrasubject variability of cerebral rSO2 readings for left and right probe and malfunction sites (n = 131) are as follows: VariableOverall, mean SO2Distal, mean SO2Proximal, mean rSO2PLeft cerebral rSO2 trend69.1 (10.7)67.7 (9.81)70.0 (11.17).23Right cerebral rSO2 trend71.3 (9.6)70.5 (8.13)71.8 (10.40).42Left cerebral rSO2 variability3.57 (2.04)4.72 (2.55)2.88 (1.24)<.001Right cerebral rSO2 variability3.46 (1.95)3.77 (2.20)3.28 (1.77).19 Intrasubject left and right rSO2 Pearson correlation was −0.46 to 0.98 (mean ± SD, 0.35 ± 0.34; median, 0.34; interquartile range, 0.06–0.61). The correlation coefficients of 99 subjects between left and right rSO2 was significantly different (P < .001), suggesting that intrasubjects' left and right rSO2 are highly correlated. Sample mean difference between left and right rSO2 were −1.7% (95% confidence interval [CI], −1.8 to −1.6; P < .001) supporting overall left lower than right. Intraclass correlation for left rSO2 was 87.4% (95% CI, 87.2%−87.6%), and that for right rSO2 was 83.8% (95% CI, 83.8%−84%), showing intersubject differences accounting for the variation, and relative to intersubject variation, intrasubjects readings are consistent. Intrasubjects

  2. Changes in cerebral blood oxygenation induced by active standing test in children with POTS and NMS.

    Science.gov (United States)

    Endo, Ayumi; Fujita, Yukihiko; Fuchigami, Tatsuo; Takahashi, Shori; Mugishima, Hideo; Skatani, Kaoru

    2014-01-01

    Orthostatic dysregulation (OD) has been classified into subtypes by heart rate and blood pressure; however, the hemodynamics of brains have not yet been revealed. Therefore, we investigated changes in cerebral blood flow and oxygenation during an active standing test to clarify the pathophysiology of two subtypes: postural tachycardia syndrome (POTS) and neurally mediated syncope (NMS). We studied 31 children (15 boys, 16 girls; mean age, 14.0 ± 1.7 years) who presented with OD at the Department of Pediatrics and Child Health, Nihon University School of Medicine between 2009 and 2011. OD was diagnosed using the Japanese clinical guidelines for juvenile orthostatic dysregulation. After a 10-min resting period in the supine position, patients were asked to quickly stand up and keep upright for 10 min. Cerebral blood flow and cerebral oxygenation were measured using transcranial Doppler sonography and near-infrared spectroscopy. POTS showed a significant decrease of oxy-Hb and resistance index (RI), suggesting transient ischemia with maintainable cerebral autoregulation. NMS showed a decrease of oxy-Hb and an increase of RI, suggesting ischemia and impairment of autoregulation.

  3. Effects of autoregulation and CO2 reactivity on cerebral oxygen transport.

    Science.gov (United States)

    Payne, S J; Selb, J; Boas, D A

    2009-11-01

    Both autoregulation and CO(2) reactivity are known to have significant effects on cerebral blood flow and thus on the transport of oxygen through the vasculature. In this paper, a previous model of the autoregulation of blood flow in the cerebral vasculature is expanded to include the dynamic behavior of oxygen transport through binding with hemoglobin. The model is used to predict the transfer functions for both oxyhemoglobin and deoxyhemoglobin in response to fluctuations in arterial blood pressure and arterial CO(2) concentration. It is shown that only six additional nondimensional groups are required in addition to the five that were previously found to characterize the cerebral blood flow response. A resonant frequency in the pressure-oxyhemoglobin transfer function is found to occur in the region of 0.1 Hz, which is a frequency of considerable physiological interest. The model predictions are compared with results from the published literature of phase angle at this frequency, showing that the effects of changes in breathing rate can significantly alter the inferred phase dynamics between blood pressure and hemoglobin. The question of whether dynamic cerebral autoregulation is affected under conditions of stenosis or stroke is then examined.

  4. Androgenic/estrogenic balance in the male rat cerebral circulation: metabolic enzymes and sex steroid receptors.

    Science.gov (United States)

    Gonzales, Rayna J; Ansar, Saema; Duckles, Sue P; Krause, Diana N

    2007-11-01

    Tissues from males can be regulated by a balance of androgenic and estrogenic effects because of local metabolism of testosterone and expression of relevant steroid hormone receptors. As a critical first step to understanding sex hormone influences in the cerebral circulation of males, we investigated the presence of enzymes that metabolize testosterone to active products and their respective receptors. We found that cerebral blood vessels from male rats express 5alpha-reductase type 2 and aromatase, enzymes responsible for conversion of testosterone into dihydrotestosterone (DHT) and 17beta-estradiol, respectively. Protein levels of these enzymes, however, were not modulated by long-term in vivo hormone treatment. We also showed the presence of receptors for both androgens (AR) and estrogens (ER) from male cerebral vessels. Western blot analysis showed bands corresponding to the full-length AR (110 kDa) and ERalpha (66 kDa). Long-term in vivo treatment of orchiectomized rats with testosterone or DHT, but not estrogen, increased AR levels in cerebral vessels. In contrast, ERalpha protein levels were increased after in vivo treatment with estrogen but not testosterone. Fluorescent immunostaining revealed ERalpha, AR, and 5alpha-reductase type 2 in both the endothelial and smooth muscle layers of cerebral arteries, whereas aromatase staining was solely localized to the endothelium. Thus, cerebral vessels from males are target tissues for both androgens and estrogen. Furthermore, local metabolism of testosterone might balance opposing androgenic and estrogenic influences on cerebrovascular as well as brain function in males.

  5. Closed versus open endotracheal suctioning in preterm infants: effects on cerebral oxygenation and blood volume.

    Science.gov (United States)

    Mosca, F A; Colnaghi, M; Lattanzio, M; Bray, M; Pugliese, S; Fumagalli, M

    1997-01-01

    The aim of our study was to compare, using near-infrared spectroscopy (NIRS), the effects on cerebral intracellular oxygenation and cerebral blood volume (CBV) of closed endotracheal suctioning (CS), which permits continuous ventilation of the patient, with open endotracheal suctioning (OS), which requires disconnection from the ventilator. Eleven preterm infants were studied. Each patient underwent one CS, followed, after 60 min, by one OS, or vice versa, three times during the same day. Modifications in CBV and oxidized cytochrome oxidase (CytO2) were continuously detected by NIRS; arterial oxygen saturation (SaO2) heart rate (HR), transcutaneous carbon dioxide tension and mean arterial blood pressure were simultaneously recorded. Significant reductions in HR and SaO2 were observed following OS; the magnitude and duration of these negative effects of suctioning were significantly reduced with CS. In addition, the decrease in CBV was more pronounced than following CS. No changes in CytO2 concentration were seen.

  6. Transient hyperoxia does not affect regional cerebral tissue oxygen saturation in moderately preterm or term newborns

    DEFF Research Database (Denmark)

    Thing, Mira; Sørensen, Line Carøe; Pryds, Ole

    2015-01-01

    oxygen saturation (rStO2 ) and to evaluate whether any observed prolonged cerebral vasoconstriction was related to maturity. METHODS: The study included 30 infants with a postmenstrual age of more than 32 weeks, who were treated with nasal continuous positive airway pressure and a fraction of inspired......, with a mean difference of 1.37% (95% CI 0.15, 2.6). After the second oxygen exposure, rStO2 remained unchanged with a mean difference of -0.4% (95% CI -1.6, 0.78). Differences in rStO2 were not related to gestational age in either of the two hyperoxic episodes. CONCLUSION: We found no evidence to support...... the theory that transient hyperoxia induces prolonged cerebral vasoconstriction in infants with a postmenstrual age above 32 weeks....

  7. 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 norep......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...... infused at 0.1 microg kg(-1) min(-1) [Sc(O2): 78 (75-94) to 69 (61-83)%; P cm s(-1); P

  8. Maternal antihypertensive drugs may influence cerebral oxygen extraction in preterm infants during the first days after birth

    NARCIS (Netherlands)

    Verhagen, Elise A.; Kooi, Elisabeth M. W.; van den Berg, Paul P.; Bos, Arend F.

    2013-01-01

    Objective: To determine whether maternal antihypertensive drugs influenced cerebral oxygenation in preterm infants during the first days after birth. Methods: We included 49 preterm infants (median gestational age 30.3 weeks, (range 26.0-31.9), birth weight 1250 g (560-2250)). Regional cerebral oxyg

  9. Continuous Dissolved Oxygen Measurements and Modelling Metabolism in Peatland Streams

    OpenAIRE

    2016-01-01

    Stream water dissolved oxygen was monitored in a 3.2km2 moorland headwater catchment in the Scottish Highlands. The stream consists of three 1st order headwaters and a 2nd order main stem. The stream network is fringed by peat soils with no riparian trees, though dwarf shrubs provide shading in the lower catchment. Dissolved oxygen (DO) is regulated by the balance between atmospheric re-aeration and the metabolic processes of photosynthesis and respiration. DO was continuously measured for >1...

  10. 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

  11. 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.

  12. 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 tension...... decreased gradually to 70% of the control value, indicating hyperventilation. At sea level hyperventilation will not increase brain oxygenation significantly in normal man, as the arterial oxygen content only increases minimally, while CBF is unchanged. At high altitude the beneficial effects...... of acetazolamide on the symptoms of acute mountain sickness may well be due to an improved oxygen supply to the brain, as hyperventilation will, at the low ambient PO2, cause a significant increase of the arterial oxygen content, while CBF presumably is unaffected by the drug. During hypoxia at high altitude...

  13. [Study of regional cerebral glucose metabolism, in man, while awake or asleep, by positron emission tomography].

    Science.gov (United States)

    Franck, G; Salmon, E; Poirrier, R; Sadzot, B; Franco, G

    1987-03-01

    Measurements of regional cerebral glucose uptake by the 18F-fluorodeoxyglucose technique (18FDG) and positron emission tomography (PET) along with polygraph recordings were made serially during relaxed wakefulness and different stages of nocturnal sleep in two right-handed normal volunteers. During stage III-IV sleep, values declined diffusely in both hemispheric regions (-31%), thalamus (-33%), cerebellum (-33%) and brain stem (-25%). During paradoxical sleep regional values increased diffusely compared with slow wave sleep. Compared to wakefulness, regional metabolic values seemed to increase but the results were more variable from one volunteer to the other. These preliminary data indicate important regional alterations in cerebral metabolism between sleep states.

  14. Complementary acupuncture treatment increases cerebral metabolism in patients with Parkinson's disease.

    Science.gov (United States)

    Huang, Yong; Jiang, Xuemei; Zhuo, Ying; Tang, Anwu; Wik, Gustav

    2009-01-01

    We used positron emission tomography (PET) and the 18-flourodeoxyglucose tracer to study cerebral effects of complementary acupuncture in Parkinson's disease. Five patients received scalp-acupuncture and Madopa, while the other five had Madopa only. PET scans before and after 5 weeks of complementary acupuncture treatment show increased glucose metabolisms in parietal, temporal, occipital lobes, the thalamus, and the cerebellum in the light-diseased hemisphere, and in parietal and occipital lobes of the severe-diseased hemisphere. No changes were observed in the Madopa-only group. Acupuncture in combination with Madopa may improve cerebral glucose metabolism in Parkinson's disease.

  15. Energy and Oxygen Metabolism Disorder During Septic Acute Kidney Injury

    Directory of Open Access Journals (Sweden)

    Rong-li Yang

    2014-08-01

    Full Text Available Background/Aims: Acute kidney injury (AKI during septic shock, which is one of the most common clinical syndromes in the intensive care unit (ICU, has a high mortality rate and poor prognosis, partly because of a poor understanding of the pathogenesis of renal dysfunction during septic shock. Although ischemic injury of the kidney has been reported to result from adenosine triphosphate (ATP depletion, increasing evidence has demonstrated that AKI occurs in the absence of renal hypoperfusion and even occurs during normal or increased renal blood flow (RBF; nevertheless, whether energy metabolism disorder is involved in septic AKI and whether it changes according to renal hemodynamics have not been established. Moreover, tubular cell apoptosis, which is closely related to ATP depletion, rather than necrosis, has been shown to be the major form of cell injury during AKI. Methods: We used canine endotoxin shock models to investigate the hemodynamics, renal energy metabolism, renal oxygen metabolism, and pathological changes during septic AKI and to explore the underlying mechanisms of septic AKI. Results: The present results revealed that the nicotinamide adenine dinucleotide (NAD+ pool and the ATP/adenosine diphosphate (ADP ratio were significantly decreased during the early phase of septic AKI, which is accompanied by a decreased renal oxygen extraction ratio (O2ER% and decreased renal oxygen consumption (VO2. Furthermore, significant apoptosis was observed following renal dysfunction. RBF and renal oxygen delivery were not significantly altered. Conclusion: These results suggest that imbalanced energy metabolism, rather than tubular cell apoptosis, may be the initiator of renal dysfunction during septic shock.

  16. Cerebral Oxygenation and Oxygen Extraction in the Preterm Infant during Desaturation : Effects of Increasing FiO(2) to Assist Recovery

    NARCIS (Netherlands)

    Baerts, Willem; Lemmers, Petra M. A.; van Bel, Frank

    2011-01-01

    Background: In the clinical setting, episodes of desaturation in newborn infants are often treated by increasing the fraction of inspired oxygen (FiO(2)). Objectives: To study the effect of an increase in FiO(2) on cerebral oxygenation during recovery from desaturation, as measured by near-infrared

  17. 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

  18. Validity of using a 3-dimensional PET scanner during inhalation of 15O-labeled oxygen for quantitative assessment of regional metabolic rate of oxygen in man.

    Science.gov (United States)

    Hori, Yuki; Hirano, Yoshiyuki; Koshino, Kazuhiro; Moriguchi, Tetsuaki; Iguchi, Satoshi; Yamamoto, Akihide; Enmi, Junichiro; Kawashima, Hidekazu; Zeniya, Tsutomu; Morita, Naomi; Nakagawara, Jyoji; Casey, Michael E; Iida, Hidehiro

    2014-09-21

    Use of 15O labeled oxygen (15O2) and positron emission tomography (PET) allows quantitative assessment of the regional metabolic rate of oxygen (CMRO2) in vivo, which is essential to understanding the pathological status of patients with cerebral vascular and neurological disorders. The method has, however, been challenging, when a 3D PET scanner is employed, largely attributed to the presence of gaseous radioactivity in the trachea and the inhalation system, which results in a large amount of scatter and random events in the PET assessment. The present study was intended to evaluate the adequacy of using a recently available commercial 3D PET scanner in the assessment of regional cerebral radioactivity distribution during an inhalation of 15O2. Systematic experiments were carried out on a brain phantom. Experiments were also performed on a healthy volunteer following a recently developed protocol for simultaneous assessment of CMRO2 and cerebral blood flow, which involves sequential administration of 15O2 and C15O2. A particular intention was to evaluate the adequacy of the scatter-correction procedures. The phantom experiment demonstrated that errors were within 3% at the practically maximum radioactivity in the face mask, with the greatest radioactivity in the lung. The volunteer experiment demonstrated that the counting rate was at peak during the 15O gas inhalation period, within a verified range. Tomographic images represented good quality over the entire FOV, including the lower part of the cerebral structures and the carotid artery regions. The scatter-correction procedures appeared to be important, particularly in the process to compensate for the scatter originating outside the FOV. Reconstructed images dramatically changed if the correction was carried out using inappropriate procedures. This study demonstrated that accurate reconstruction could be obtained when the scatter compensation was appropriately carried out. This study also suggested the

  19. Oxygen consumption and blood flow coupling in human motor cortex during intense finger tapping

    DEFF Research Database (Denmark)

    Seyedi Vafaee, Manouchehr; Vang, Kim; Bergersen, Linda H

    2012-01-01

    Rates of cerebral blood flow (CBF) and glucose consumption (CMR(glc)) rise in cerebral cortex during continuous stimulation, while the oxygen-glucose index (OGI) declines as an index of mismatched coupling of oxygen consumption (cerebral metabolic rate of oxygen-CMRO(2)) to CBF and CMR...

  20. Program for PET image alignment: Effects on calculated differences in cerebral metabolic rates for glucose

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, R.L.; London, E.D.; Links, J.M.; Cascella, N.G. (NIDA Addiction Research Center, Baltimore, MD (USA))

    1990-12-01

    A program was developed to align positron emission tomography images from multiple studies on the same subject. The program allowed alignment of two images with a fineness of one-tenth the width of a pixel. The indications and effects of misalignment were assessed in eight subjects from a placebo-controlled double-blind crossover study on the effects of cocaine on regional cerebral metabolic rates for glucose. Visual examination of a difference image provided a sensitive and accurate tool for assessing image alignment. Image alignment within 2.8 mm was essential to reduce variability of measured cerebral metabolic rates for glucose. Misalignment by this amount introduced errors on the order of 20% in the computed metabolic rate for glucose. These errors propagate to the difference between metabolic rates for a subject measured in basal versus perturbed states.

  1. 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

  2. Cerebral blood flow and metabolism for Broca's aphasia using positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Toshiaki

    1987-12-01

    A total of 11 patients with Broca's aphasia (BA) underwent positron emission tomography (PET) with the purpose of investigating the responsible region and the symptomatic flow and metabolism thresholds for BA. Computed tomography (CT) was concurrently performed. In the group of 3 patients undergoing PET with C-11 glucose, both PET and CT provided abnormal findings in the region that is thought to be responsible for BA (Broca's area), including the cortex and subcortex in the anterior region to Sylvian fissure. The Broca's area in the remaining one was shown as low C-11 accumulation area on PET and as isodensity on CT. The second group, consisting of 8 BA patients and 30 control patients without BA, underwent PET using O-15 steady method. PET showed reduction of regional cerebral blood flow (rCBF) and oxygen metabolic rate (rCMRO/sub 2/) in the Broca's area in all BA patients. Computed tomography showed abnormal low density in the Broca's area in 3 patients, and abnormal findings in the basal ganglionic region and subcortex without evidence for abnormal low density in the Broca's area in the other 5 patients. Comparison of rCBF and rCMRO/sub 2/ in BA patients with those in control patients may show the symptomatic thresholds to be 20 - 27 ml100 gmin for rCBF and 2.0 ml100 gmin for rCMRO/sub 2/. (Namekawa, K.).

  3. New insights into coupling and uncoupling of cerebral blood flow and metabolism in the brain

    OpenAIRE

    2016-01-01

    The brain has high metabolic and energy needs and requires continuous cerebral blood flow (CBF), which is facilitated by a tight coupling between neuronal activity, CBF, and metabolism. Upon neuronal activation, there is an increase in energy demand, which is then met by a hemodynamic response that increases CBF. Such regional CBF increase in response to neuronal activation is observed using neuroimaging techniques such as functional magnetic resonance imaging and positron emission tomography...

  4. Brain Size and Cerebral Glucose Metabolic Rate in Nonspecific Retardation and Down Syndrome.

    Science.gov (United States)

    Haier, Richard J.; And Others

    1995-01-01

    Brain size and cerebral glucose metabolic rate were determined for 10 individuals with mild mental retardation (MR), 7 individuals with Down syndrome (DS), and 10 matched controls. MR and DS groups both had brain volumes of about 80% compared to controls, with variance greatest within the MR group. (SLD)

  5. Cerebral perfusion and metabolism in resuscitated patients with severe post-hypoxic encephalopathy

    NARCIS (Netherlands)

    Schaafsma, A.; de Jong, B M; Bams, J.L.; Haaxma-Reiche, H; Pruim, J; Zijlstra, J G

    2003-01-01

    Positron emission tomography (PET) was used for the study of regional cerebral perfusion and metabolism in eight patients with severe post-hypoxic encephalopathy, caused by cardiac arrest and resulting in a coma lasting for at least 24 h. Using this method, we aimed to identify regional vulnerabilit

  6. Changes to coral health and metabolic activity under oxygen deprivation

    Directory of Open Access Journals (Sweden)

    James W.A. Murphy

    2016-04-01

    Full Text Available On Hawaiian reefs, the fast-growing, invasive algae Gracilaria salicornia overgrows coral heads, restricting water flow and light, thereby smothering corals. Field data shows hypoxic conditions (dissolved oxygen (DO2 < 2 mg/L occurring underneath algal mats at night, and concurrent bleaching and partial tissue loss of shaded corals. To analyze the impact of nighttime oxygen-deprivation on coral health, this study evaluated changes in coral metabolism through the exposure of corals to chronic hypoxic conditions and subsequent analyses of lactate, octopine, alanopine, and strombine dehydrogenase activities, critical enzymes employed through anaerobic respiration. Following treatments, lactate and octopine dehydrogenase activities were found to have no significant response in activities with treatment and time. However, corals subjected to chronic nighttime hypoxia were found to exhibit significant increases in alanopine dehydrogenase activity after three days of exposure and strombine dehydrogenase activity starting after one overnight exposure cycle. These findings provide new insights into coral metabolic shifts in extremely low-oxygen environments and point to ADH and SDH assays as tools for quantifying the impact of hypoxia on coral health.

  7. Changes to coral health and metabolic activity under oxygen deprivation

    Science.gov (United States)

    Richmond, Robert H.

    2016-01-01

    On Hawaiian reefs, the fast-growing, invasive algae Gracilaria salicornia overgrows coral heads, restricting water flow and light, thereby smothering corals. Field data shows hypoxic conditions (dissolved oxygen (DO2) < 2 mg/L) occurring underneath algal mats at night, and concurrent bleaching and partial tissue loss of shaded corals. To analyze the impact of nighttime oxygen-deprivation on coral health, this study evaluated changes in coral metabolism through the exposure of corals to chronic hypoxic conditions and subsequent analyses of lactate, octopine, alanopine, and strombine dehydrogenase activities, critical enzymes employed through anaerobic respiration. Following treatments, lactate and octopine dehydrogenase activities were found to have no significant response in activities with treatment and time. However, corals subjected to chronic nighttime hypoxia were found to exhibit significant increases in alanopine dehydrogenase activity after three days of exposure and strombine dehydrogenase activity starting after one overnight exposure cycle. These findings provide new insights into coral metabolic shifts in extremely low-oxygen environments and point to ADH and SDH assays as tools for quantifying the impact of hypoxia on coral health. PMID:27114888

  8. 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

  9. Nitrogen Metabolism During Hepatectomy and Hyperbaric Oxygenation: Experimental Study

    Directory of Open Access Journals (Sweden)

    P. N. Savilov

    2007-01-01

    Full Text Available Objective: to examine nitrogen metabolism in the organs of the portal system during liver resection (LR and hyperbaric oxygenation (HBO.Material and methods: Experiments were conducted on 65 female albino rats. LR was made under ether anesthesia, by removing a portion of the left hepatic lobe with an electric knife, which amounted to 15—20% of the organ’s mass. HBO was performed using medical oxygen at 3 ata for 50 min once daily within the first three days after LR. Lung tissue, gastrointestinal tract (GIT, spleen, and choledochal bile were the subject of the study. The tissue and blood levels of ammonia, glutamine, and urea were measured.Results: LR leads to pathological ammonia accumulation and decreases arterial glutamine consumption in GIT organs. Concurrently, the urea contained in the organs begins to come into portal blood flow, splenic glutamine deficiency develops, and hepatic ammonia-absorptive, glutamine- and urea-excretory functions diminish. Post-LR HBO prevents the accumulation of ammonia in the liver and GIT, restores the ammonia-absorptive, glutamine- and urea-excretory functions of the liver, and stimulates its glutamine and urea accumulation. Concomitantly, under HBO, there is an increase in glutamine entrance from the GIT into blood flow, but there is a decrease in GIT urea excretion and portal venous blood ammonia levels. HBO eliminates arterial hyperammonemia after LR and splenic glutamine deficiency.Conclusion: Hyperbaric oxygen eliminates nitrogen metabolic disturbances in the portal system, regulates compensatory-adaptive ammonia metabolic reactions triggered in the GIT and spleen during LR. 

  10. A reduced cerebral metabolic ratio in exercise reflects metabolism and not accumulation of lactate within the human brain

    DEFF Research Database (Denmark)

    Dalsgaard, Mads K; Quistorff, Bjørn; Danielsen, Else R

    2003-01-01

    During maximal exercise lactate taken up by the human brain contributes to reduce the cerebral metabolic ratio, O(2)/(glucose + 1/2 lactate), but it is not known whether the lactate is metabolized or if it accumulates in a distribution volume. In one experiment the cerebral arterio...... young subjects. In a second experiment magnetic resonance spectroscopy ((1)H-MRS) was performed after exhaustive exercise to assess lactate levels in the brain (n = 5). Exercise increased the AV(O2) from 3.2 +/- 0.1 at rest to 3.5 +/- 0.2 mM (mean +/-s.e.m.; P ...-venous differences (AV) for O(2), glucose (glc) and lactate (lac) were evaluated in nine healthy subjects at rest and during and after exercise to exhaustion. The cerebrospinal fluid (CSF) was drained through a lumbar puncture immediately after exercise, while control values were obtained from six other healthy...

  11. Cerebral glucose metabolism in Wernicke's, Broca's, and conduction aphasia

    Energy Technology Data Exchange (ETDEWEB)

    Metter, E.J.; Kempler, D.; Jackson, C.; Hanson, W.R.; Mazziotta, J.C.; Phelps, M.E.

    1989-01-01

    Cerebral glucose metabolism was evaluated in patients with either Wernicke's (N = 7), Broca's (N = 11), or conduction (N = 10) aphasia using /sup 18/F-2-fluoro-2-deoxy-D-glucose with positron emission tomography. The three aphasic syndromes differed in the degree of left-to-right frontal metabolic asymmetry, with Broca's aphasia showing severe asymmetry and Wernicke's aphasia mild-to-moderate metabolic asymmetry, while patients with conduction aphasia were metabolically symmetric. On the other hand, the three syndromes showed the same degree of metabolic decline in the left temporal region. The parietal region appeared to separate conduction aphasia from both Broca's and Wernicke's aphasias. Common aphasic features in the three syndromes appear to be due to common changes in the temporal region, while unique features were associated with frontal and parietal metabolic differences.

  12. Voxel-based statistical analysis of cerebral glucose metabolism in patients with permanent vegetative state after acquired brain injury

    Institute of Scientific and Technical Information of China (English)

    Yong Wook Kim; Hyoung Seop Kim; Young-Sil An; Sang Hee Im

    2010-01-01

    Background Permanent vegetative state is defined as the impaired level of consciousness longer than 12 months after traumatic causes and 3 months after non-traumatic causes of brain injury. Although many studies assessed the cerebral metabolism in patients with acute and persistent vegetative state after brain injury, few studies investigated the cerebral metabolism in patients with permanent vegetative state. In this study, we performed the voxel-based analysis of cerebral glucose metabolism and investigated the relationship between regional cerebral glucose metabolism and the severity of impaired consciousness in patients with permanent vegetative state after acquired brain injury.Methods We compared the regional cerebral glucose metabolism as demonstrated by F-18 fluorodeoxyglucose positron emission tomography from 12 patients with permanent vegetative state after acquired brain injury with those from 12 control subjects. Additionally, covariance analysis was performed to identify regions where decreased changes in regional cerebral glucose metabolism significantly correlated with a decrease of level of consciousness measured by JFK-coma recovery scare. Statistical analysis was performed using statistical parametric mapping.Results Compared with controls, patients with permanent vegetative state demonstrated decreased cerebral glucose metabolism in the left precuneus, both posterior cingulate cortices, the left superior parietal lobule (Pcorrected <0.001), and increased cerebral glucose metabolism in the both cerebellum and the right supramarginal cortices (Pcorrected <0.001). In the covariance analysis, a decrease in the level of consciousness was significantly correlated with decreased cerebral glucose metabolism in the both posterior cingulate cortices (Puncorrected <0.005).Conclusion Our findings suggest that the posteromedial parietal cortex, which are part of neural network for consciousness, may be relevant structure for pathophysiological mechanism

  13. APP Metabolism Regulates Tau Proteostasis in Human Cerebral Cortex Neurons

    Directory of Open Access Journals (Sweden)

    Steven Moore

    2015-05-01

    Full Text Available Accumulation of Aβ peptide fragments of the APP protein and neurofibrillary tangles of the microtubule-associated protein tau are the cellular hallmarks of Alzheimer’s disease (AD. To investigate the relationship between APP metabolism and tau protein levels and phosphorylation, we studied human-stem-cell-derived forebrain neurons with genetic forms of AD, all of which increase the release of pathogenic Aβ peptides. We identified marked increases in intracellular tau in genetic forms of AD that either mutated APP or increased its dosage, suggesting that APP metabolism is coupled to changes in tau proteostasis. Manipulating APP metabolism by β-secretase and γ-secretase inhibition, as well as γ-secretase modulation, results in specific increases and decreases in tau protein levels. These data demonstrate that APP metabolism regulates tau proteostasis and suggest that the relationship between APP processing and tau is not mediated solely through extracellular Aβ signaling to neurons.

  14. Effects of incremental exercise on cerebral oxygenation measured by near-infrared spectroscopy: a systematic review.

    Science.gov (United States)

    Rooks, Cherie R; Thom, Nathaniel J; McCully, Kevin K; Dishman, Rod K

    2010-10-01

    We conducted a systematic review and meta-regression analysis to quantify effects of exercise on brain hemodynamics measured by near-infrared spectroscopy (NIRS). The results indicate that acute incremental exercise (categorized relative to aerobic capacity (VO(2)peak) as low - <30% VO(2)peak; moderate - ≥30% VO(2)peak to <60% VO(2)peak; hard - ≥60% VO(2)peak to oxygenated hemoglobin (O(2)Hb) or other measures of oxygen level (O(2)Hbdiff) or saturation (SCO(2)) (0.92±0.67, 1.17), deoxygenated hemoglobin (dHb) (0.87±0.56, 1.19), and blood volume estimated by total hemoglobin (tHb) (1.21±0.84, 1.59). After peaking at hard intensities, cerebral oxygen levels dropped during very hard intensities. People who were aerobically trained attained higher levels of cortical oxygen, dHb, and tHb than untrained people during very hard intensities. Among untrained people, a marked drop in oxygen levels and a small increase in dHb at very hard intensities accompanied declines in tHb, implying reduced blood flow. In 6 studies of 222 patients with heart or lung conditions, oxygenation and dHb were lowered or unchanged during exercise compared to baseline. In conclusion, prefrontal oxygenation measured with NIRS in healthy people showed a quadratic response to incremental exercise, rising between moderate and hard intensities, then falling at very hard intensities. Training status influenced the responses. While methodological improvements in measures of brain oxygen are forthcoming, these results extend the evidence relevant to existing models of central limitations to maximal exercise.

  15. Determination of patterns of regional cerebral glucose metabolism in normal aging and dementia

    Energy Technology Data Exchange (ETDEWEB)

    Alavi, A.; Chawluk, J.; Hurtig, H.; Dann, R.; Rosen, M.; Kushner, M.; Silver, F.; Reivich, M.

    1985-05-01

    Regional cerebral metabolic rates for glucose (rCMRGlc) were measured using 18F-FDG and positron emission tomography (PET) in 14 patients with probable Alzheimer's disease (AD) (age=64), 9 elderly controls (age=61), and 9 young controls (age=28). PET studies were performed without sensory stimulation or deprivation. Metabolic rates in individual brain regions were determined using an atlas overlay. Relative metabolic rates (rCMRGl c/global CMRGlc) were determined for all subjects. Comparison of young and elderly controls demonstrated significant decreases in frontal metabolism (rho<0.005) and right inferior parietal (IP) metabolism (rho<0.02) with normal aging. Patients with mild-moderate AD (NMAD) (n=8) when compared to age-matched controls, showed further reduction in right IP metabolism (rho<0.02). SAD patients also demonstrated metabolic decrements in left hemisphere language areas (rho<0.01). This latter finding is consistent with language disturbance observed late in the course of the disease. Out data reveal progressive changes in patterns of cerebral glucose utilization with aging and demential with reflect salient clinical features of these processes.

  16. A Quantitative Study of Oxygen as a Metabolic Regulator

    Science.gov (United States)

    Radhakrishnan, Krishnan; LaManna, Joseph C.; Cabrera, Marco E.

    1999-01-01

    An acute reduction in oxygen (O2) delivery to a tissue is generally associated with a decrease in phosphocreatine, increases in ADP, NADH/NAD, and inorganic phosphate, increased rates of glycolysis and lactate production, and reduced rates of pyruvate and fatty acid oxidation. However, given the complexity of the human bioenergetic system and its components, it is difficult to determine quantitatively how cellular metabolic processes interact to maintain ATP homeostasis during stress (e.g., hypoxia, ischemia, and exercise). Of special interest is the determination of mechanisms relating tissue oxygenation to observed metabolic responses at the tissue, organ, and whole body levels and the quantification of how changes in tissue O2 availability affect the pathways of ATP synthesis and the metabolites that control these pathways. In this study, we extend a previously developed mathematical model of human bioenergetics to provide a physicochemical framework that permits quantitative understanding of O2 as a metabolic regulator. Specifically, the enhancement permits studying the effects of variations in tissue oxygenation and in parameters controlling the rate of cellular respiration on glycolysis, lactate production, and pyruvate oxidation. The whole body is described as a bioenergetic system consisting of metabolically distinct tissue/organ subsystems that exchange materials with the blood. In order to study the dynamic response of each subsystem to stimuli, we solve the ordinary differential equations describing the temporal evolution of metabolite levels, given the initial concentrations. The solver used in the present study is the packaged code LSODE, as implemented in the NASA Lewis kinetics and sensitivity analysis code, LSENS. A major advantage of LSENS is the efficient procedures supporting systematic sensitivity analysis, which provides the basic methods for studying parameter sensitivities (i.e., changes in model behavior due to parameter variation

  17. Low Cerebral Glucose Metabolism: A Potential Predictor for the Severity of Vascular Parkinsonism and Parkinson's Disease.

    Science.gov (United States)

    Xu, Yunqi; Wei, Xiaobo; Liu, Xu; Liao, Jinchi; Lin, Jiaping; Zhu, Cansheng; Meng, Xiaochun; Xie, Dongsi; Chao, Dongman; Fenoy, Albert J; Cheng, Muhua; Tang, Beisha; Zhang, Zhuohua; Xia, Ying; Wang, Qing

    2015-11-01

    This study explored the association between cerebral metabolic rates of glucose (CMRGlc) and the severity of Vascular Parkinsonism (VP) and Parkinson's disease (PD). A cross-sectional study was performed to compare CMRGlc in normal subjects vs. VP and PD patients. Twelve normal subjects, 22 VP, and 11 PD patients were evaluated with the H&Y and MMSE, and underwent 18F-FDG measurements. Pearson's correlations were used to identify potential associations between the severity of VP/PD and CMRGlc. A pronounced reduction of CMRGlc in the frontal lobe and caudate putamen was detected in patients with VP and PD when compared with normal subjects. The VP patients displayed a slight CMRGlc decrease in the caudate putamen and frontal lobe in comparison with PD patients. These decreases in CMRGlc in the frontal lobe and caudate putamen were significantly correlated with the VP patients' H&Y, UPDRS II, UPDRS III, MMSE, cardiovascular, and attention/memory scores. Similarly, significant correlations were observed in patients with PD. This is the first clinical study finding strong evidence for an association between low cerebral glucose metabolism and the severity of VP and PD. Our findings suggest that these changes in glucose metabolism in the frontal lobe and caudate putamen may underlie the pathophysiological mechanisms of VP and PD. As the scramble to find imaging biomarkers or predictors of the disease intensifies, a better understanding of the roles of cerebral glucose metabolism may give us insight into the pathogenesis of VP and PD.

  18. Effect of oxygen on lactose metabolism in lactic streptococci.

    Science.gov (United States)

    Smart, J B; Thomas, T D

    1987-03-01

    Three strains of Streptococcus lactis, two of Streptococcus cremoris, and one of Streptococcus thermophilus metabolized oxygen in the presence of added carbohydrate primarily via a closely coupled NADH oxidase/NADH peroxidase system. No buildup of the toxic intermediate H(2)O(2) was detected with the three S. lactis strains. All six strains contained significant superoxide dismutase activity and are clearly aerotolerant. Lactose- or glucose-driven oxygen consumption was biphasic, with a rapid initial rate followed by a slower secondary rate which correlated with factors affecting the in vivo activation of lactate dehydrogenase. The rate of oxygen consumption was rapid under conditions that led to a reduction in lactate dehydrogenase activity (low intracellular fructose 1,6-bisphosphate concentration). These conditions could be achieved with nongrowing cells by adding lactose at a constant but limiting rate. When the rate of lactose fermentation was limited to 5% of its maximum, nongrowing cells of S. lactis strains ML3 and ML8 carried out an essentially homoacetic fermentation under aerobic conditions. These same cells carried out the expected homolactic fermentation when presented with excess lactose under anaerobic conditions. Homoacetic fermentation leads to the generation of more energy, by substrate-level phosphorylation via acetate kinase, than the homolactic fermentation. However, it was not observed in growing cells and was restricted to slow fermentation rates with nongrowing cells.

  19. 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.

  20. 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.

  1. Lactate storm marks cerebral metabolism following brain trauma.

    Science.gov (United States)

    Lama, Sanju; Auer, Roland N; Tyson, Randy; Gallagher, Clare N; Tomanek, Boguslaw; Sutherland, Garnette R

    2014-07-18

    Brain metabolism is thought to be maintained by neuronal-glial metabolic coupling. Glia take up glutamate from the synaptic cleft for conversion into glutamine, triggering glial glycolysis and lactate production. This lactate is shuttled into neurons and further metabolized. The origin and role of lactate in severe traumatic brain injury (TBI) remains controversial. Using a modified weight drop model of severe TBI and magnetic resonance (MR) spectroscopy with infusion of (13)C-labeled glucose, lactate, and acetate, the present study investigated the possibility that neuronal-glial metabolism is uncoupled following severe TBI. Histopathology of the model showed severe brain injury with subarachnoid and hemorrhage together with glial cell activation and positive staining for Tau at 90 min post-trauma. High resolution MR spectroscopy of brain metabolites revealed significant labeling of lactate at C-3 and C-2 irrespective of the infused substrates. Increased (13)C-labeled lactate in all study groups in the absence of ischemia implied activated astrocytic glycolysis and production of lactate with failure of neuronal uptake (i.e. a loss of glial sensing for glutamate). The early increase in extracellular lactate in severe TBI with the injured neurons rendered unable to pick it up probably contributes to a rapid progression toward irreversible injury and pan-necrosis. Hence, a method to detect and scavenge the excess extracellular lactate on site or early following severe TBI may be a potential primary therapeutic measure.

  2. Fatigue in Parkinson's disease: The contribution of cerebral metabolic changes.

    Science.gov (United States)

    Cho, Sang Soo; Aminian, Kelly; Li, Crystal; Lang, Anthony E; Houle, Sylvain; Strafella, Antonio P

    2017-01-01

    Fatigue is a common and disabling non-motor symptom in Parkinson's disease associated with a feeling of overwhelming lack of energy. The aim of this study was to identify the neural substrates that may contribute to the development of fatigue in Parkinson's disease. Twenty-three Parkinson's disease patients meeting UK Brain Bank criteria for the diagnosis of idiopathic Parkinson's disease were recruited and completed the 2-[(18) F]fluoro-2-deoxy-D-glucose (FDG)-PET scan. The metabolic activities of Parkinson's disease patients with fatigue were compared to those without fatigue using statistical parametric mapping analysis. The Parkinson's disease group exhibiting higher level of fatigue showed anti-correlated metabolic changes in cortical regions associated with the salience (i.e., right insular region) and default (i.e., bilateral posterior cingulate cortex) networks. The metabolic abnormalities detected in these brain regions displayed a significant correlation with level of fatigue and were associated with a disruption of the functional correlations with different cortical areas. These observations suggest that fatigue in Parkinson's disease may be the expression of metabolic abnormalities and impaired functional interactions between brain regions linked to the salience network and other neural networks. Hum Brain Mapp 38:283-292, 2017. © 2016 Wiley Periodicals, Inc.

  3. Typical Cerebral Metabolic Patterns in Neurodegenerative Brain Diseases

    NARCIS (Netherlands)

    Teune, Laura K.; Bartels, Anna L.; de Jong, Bauke M.; Willemsen, Antoon T. M.; Eshuis, Silvia A.; de Vries, Jeroen J.; van Oostrom, Joost C. H.; Leenders, Klaus L.

    2010-01-01

    The differential diagnosis of neurodegenerative brain diseases on clinical grounds is difficult, especially at an early disease stage. Several studies have found specific regional differences of brain metabolism applying [F-18]-fluoro-deoxyglucose positron emission tomography (FDG-PET), suggesting t

  4. Effects of Metformin on the Cerebral Metabolic Changes in Type 2 Diabetic Patients

    Directory of Open Access Journals (Sweden)

    Yung-Cheng Huang

    2014-01-01

    Full Text Available Metformin, a widely used antidiabetic drug, has numerous effects on human metabolism. Based on emerging cellular, animal, and epidemiological studies, we hypothesized that metformin leads to cerebral metabolic changes in diabetic patients. To explore metabolism-influenced foci of brain, we used 2-deoxy-2-[18F]fluoro-D-glucose (FDG positron emission tomography for type 2 diabetic patients taking metformin (MET, n=18, withdrawing from metformin (wdMET, n=13, and not taking metformin (noMET, n=9. Compared with the noMET group, statistical parametric mapping showed that the MET group had clusters with significantly higher metabolism in right temporal, right frontal, and left occipital lobe white matter and lower metabolism in the left parahippocampal gyrus, left fusiform gyrus, and ventromedial prefrontal cortex. In volume of interest (VOI- based group comparisons, the normalized FDG uptake values of both hypermetabolic and hypometabolic clusters were significantly different between groups. The VOI-based correlation analysis across the MET and wdMET groups showed a significant negative correlation between normalized FDG uptake values of hypermetabolic clusters and metformin withdrawal durations and a positive but nonsignificant correlation in the turn of hypometabolic clusters. Conclusively, metformin affects cerebral metabolism in some white matter and semantic memory related sites in patients with type 2 diabetes.

  5. Regional cerebral blood flow and glucose metabolism following transient forebrain ischemia.

    Science.gov (United States)

    Pulsinelli, W A; Levy, D E; Duffy, T E

    1982-05-01

    Progressive brain damage after transient cerebral ischemia may be related to changes in postischemic cerebral blood flow and metabolism. Regional cerebral blood flow (rCBF) and cerebral glucose utilization (rCGU) were measured in adult rats prior to, during (only rCBF), and serially after transient forebrain ischemia. Animals were subjected to 30 minutes of forebrain ischemia by occluding both common carotid arteries 24 hours after cauterizing the vertebral arteries. Regional CBF was measured by the indicator-fractionation technique using 4-iodo-[14C]-antipyrine. Regional CGU was measured by the 2-[14C]deoxyglucose method. The results were correlated with the distribution and progression of ischemic neuronal damage in animals subjected to an identical ischemic insult. Cerebral blood flow to forebrain after 30 minutes of moderate to severe ischemia (less than 10% control CBF) was characterized by 5 to 15 minutes of hyperemia; rCBF then fell below normal and remained low for as long as 24 hours. Post-ischemic glucose utilization in the forebrain, except in the hippocampus, was depressed below control values at 1 hour and either remained low (neocortex, striatum) or gradually rose to normal (white matter) by 48 hours. In the hippocampus, glucose utilization equaled the control value at 1 hour and fell below control between 24 and 48 hours. The appearance of moderate to severe morphological damage in striatum and hippocampus coincided with a late rise of rCBF above normal and with a fall of rCGU; the late depression of rCGU was usually preceded by a period during which metabolism was increased relative to adjacent tissue. Further refinement of these studies may help identify salvageable brain after ischemia and define ways to manipulate CBF and metabolism in the treatment of stroke.

  6. Influence of rotating magnetic field on cerebral infarction volume, cerebral edema and free radicals metabolism after cerebral ischemia/reperfusion injury in rats

    Institute of Scientific and Technical Information of China (English)

    Xiaohong Liu; Zhiqiang Zhang; Lixin Zhang

    2006-01-01

    BACKGROUND: It has shown that magnetic field can improve blood circulation, decrease blood viscosity, inhibit free radicals, affect Ca2+ flow in nerve cells, control inflammatory and immunological reaction, and accelerate nerve cell regeneration. In addition, protective effect of magnetic field, which acts as an iatrophysics, on ischemic brain tissues has been understood gradually.OBJECTIVE: To investigate the effects of rotating magnetic field (RMF) on volume of cerebral infarction,cerebral edema and metabolism of free radicals in rats after cerebral ischemia/reperfusion injury.DESIGN: Randomized controlled animal study.SETTING: Rehabilitation Center of disabled children, Liaoniang; Department of Rehabilitation, the Second Affiliated Hospital, China Medical University; Department of Rehabilitation Physiotherapy, the First Affiliated Hospital, China Medical University.MATERIALS: A total of 70 healthy Wistar rats aged 18-20 weeks of both genders were selected and randomly divided into 3 groups: sham operation group with 12 rats, control group with 20 rats and treatment group with 38 rats. The treatment group included 4 time points: immediate reperfusion with 6 ones, 6-hour reperfusion with 20 ones, 12-hour reperfusion with 6 ones and 18-hour reperfusion with 6 rats. Main instruments were detailed as follows: magnetic head of rotating magnetic device was 6 cm in diameter; magnetic induction intensity at the surface of magnetic head was 0.25 T in silence; the maximal magnetic induction intensity was 0.09 T at the phase of rotation; the average rotating speed was 2500 r per minute.METHODS: The experiment was carried out in the China Medical University in March 2003. Focal cerebral ischemic animal models were established with modified Longa's method. Operation was the same in the sham operation, but the thread was inserted as 10 mm. Neurologic impairment was assessed with 5-rating method to screen out cases. Those survivals with grade 1 and grade 2 after ischemia for 2

  7. Metabolically Derived Human Ventilation Rates: A Revised Approach Based Upon Oxygen Consumption Rates (Final Report, 2009)

    Science.gov (United States)

    EPA announced the availability of the final report, Metabolically Derived Human Ventilation Rates: A Revised Approach Based Upon Oxygen Consumption Rates. This report provides a revised approach for calculating an individual's ventilation rate directly from their oxygen c...

  8. APP metabolism regulates tau proteostasis in human cerebral cortex neurons

    OpenAIRE

    Steven Moore; Evans, Lewis D.B.; Therese Andersson; Erik Portelius; James Smith; Tatyana B. Dias; Nathalie Saurat; Amelia McGlade; Peter Kirwan; Kaj Blennow; John Hardy; Henrik Zetterberg; Frederick J. Livesey

    2015-01-01

    This is the final version. It was first published by Elsevier at http://www.sciencedirect.com/science/article/pii/S2211124715003599. Accumulation of Aβ peptide fragments of the APP protein and neurofibrillary tangles of the microtubule-associated protein tau are the cellular hallmarks of Alzheimer’s disease (AD). To investigate the relationship between APP metabolism and tau protein levels and phosphorylation, we studied human-stem-cell-derived forebrain neurons with genetic forms of AD, a...

  9. Cerebral glucose metabolism in neurofibromatosis type 1 assessed with [18F]-2-fluoro-2-deoxy-D-glucose and PET.

    OpenAIRE

    Balestri, P; Lucignani, G; Fois, A.; Magliani, L; Calistri, L; Grana, C.; Di Bartolo, R M; Perani, D; Fazio, F.

    1994-01-01

    Cerebral PET with [18F]-2-fluoro-2-deoxy-D-glucose has been performed in four patients with neurofibromatosis type 1 (NF1) to assess the relation between cerebral metabolic activity, MRI, and the presence of neurological symptoms, including seizures, as well as mental and language retardation. Widespread hypometabolism occurred in three of the patients. The lesions on MRI, which were localised in the subcortical white matter and grey structures, had normal rates of glucose metabolism. This fi...

  10. Association of genetic variants with atherothrombotic cerebral infarction in Japanese individuals with metabolic syndrome.

    Science.gov (United States)

    Yamada, Yoshiji; Kato, Kimihiko; Oguri, Mitsutoshi; Yoshida, Tetsuro; Yokoi, Kiyoshi; Watanabe, Sachiro; Metoki, Norifumi; Yoshida, Hidemi; Satoh, Kei; Ichihara, Sahoko; Aoyagi, Yukitoshi; Yasunaga, Akitomo; Park, Hyuntae; Tanaka, Masashi; Nozawa, Yoshinori

    2008-06-01

    Metabolic syndrome is a risk factor for cardiovascular disease. The aim of the present study was to identify genetic variants that confer susceptibility to atherothrombotic cerebral infarction among individuals with metabolic syndrome in order to allow prediction of genetic risk for this condition. The study population comprised 1284 unrelated Japanese individuals with metabolic syndrome, including 313 subjects with atherothrombotic cerebral infarction and 971 controls. The genotypes for 296 polymorphisms of 202 candidate genes were determined with a method that combines the polymerase chain reaction and sequence-specific oligonucleotide probes with suspension array technology. The Chi-square test, multivariable logistic regression analysis with adjustment for age, sex, body mass index, and the prevalence of hypertension, hypercholesterolemia, and diabetes mellitus, as well as a stepwise forward selection procedure revealed that the 2445G-->A (Ala54Thr) polymorphism (rs1799883) of FABP2, the -108/3G-->4G polymorphism of IPF1 (S82168), the A-->G (Thr94Ala) polymorphism (rs2241883) of FABP1, the G-->A (Asp2213Asn) polymorphism (rs529038) of ROS1, the -11377C-->G polymorphism (rs266729) of ADIPOQ, the 162A-->C polymorphism (rs4769055) of ALOX5AP, the -786T-->C polymorphism (rs2070744) of NOS3, and the 3279C-->T polymorphism (rs7291467) of LGALS2 were associated (PA (Ala54Thr) polymorphism of FABP2 was most significantly associated with this condition. Our results suggest that FABP2, IPF1, FABP1, ROS1, ADIPOQ, ALOX5AP, NOS3, and LGALS2 are susceptibility loci for atherothrombotic cerebral infarction among Japanese individuals with metabolic syndrome. Genotypes for these polymorphisms, especially for the 2445G-->A (Ala54Thr) polymorphism of FABP2, may prove informative for the prediction of genetic risk for atherothrombotic cerebral infarction among such individuals.

  11. Metabolic effects of perinatal asphyxia in the rat cerebral cortex.

    Science.gov (United States)

    Souza, Samir Khal; Martins, Tiago Leal; Ferreira, Gustavo Dias; Vinagre, Anapaula Sommer; Silva, Roselis Silveira Martins da; Frizzo, Marcos Emilio

    2013-03-01

    We reported previously that intrauterine asphyxia acutely affects the rat hippocampus. For this reason, the early effects of this injury were studied in the cerebral cortex, immediately after hysterectomy (acute condition) or following a recovery period at normoxia (recovery condition). Lactacidemia and glycemia were determined, as well as glycogen levels in the muscle, liver and cortex. Cortical tissue was also used to assay the ATP levels and glutamate uptake. Asphyxiated pups exhibited bluish coloring, loss of movement, sporadic gasping and hypertonia. However, the appearance of the controls and asphyxiated pups was similar at the end of the recovery period. Lactacidemia and glycemia were significantly increased by asphyxia in both the acute and recovery conditions. Concerning muscle and hepatic glycogen, the control group showed significantly higher levels than the asphyxic group in the acute condition and when compared with groups of the recovery period. In the recovery condition, the control and asphyxic groups showed similar glycogen levels. However, in the cortex, the control groups showed significantly higher glycogen levels than the asphyxic group, in both the acute and recovery conditions. In the cortical tissue, asphyxia reduced ATP levels by 70 % in the acute condition, but these levels increased significantly in asphyxic pups after the recovery period. Asphyxia did not affect glutamate transport in the cortex of both groups. Our results suggest that the cortex uses different energy resources to restore ATP after an asphyxia episode followed by a reperfusion period. This strategy could sustain the activity of essential energy-dependent mechanisms.

  12. 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

  13. Omega-3 polyunsaturated fatty acids and oxygenated metabolism in atherothrombosis.

    Science.gov (United States)

    Guichardant, Michel; Calzada, Catherine; Bernoud-Hubac, Nathalie; Lagarde, Michel; Véricel, Evelyne

    2015-04-01

    Numerous epidemiological studies and clinical trials have reported the health benefits of omega-3 polyunsaturated fatty acids (PUFA), including a lower risk of coronary heart diseases. This review mainly focuses on the effects of alpha-linolenic (ALA), eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids on some risk factors associated with atherothrombosis, including platelet activation, plasma lipid concentrations and oxidative modification of low-density lipoproteins (LDL). Special focus is given to the effects of marine PUFA on the formation of eicosanoids and docosanoids, and to the bioactive properties of some oxygenated metabolites of omega-3 PUFA produced by cyclooxygenases and lipoxygenases. The antioxidant effects of marine omega-3 PUFA at low concentrations and the pro-oxidant effects of DHA at high concentrations on the redox status of platelets and LDL are highlighted. Non enzymatic peroxidation end-products deriving from omega-3 PUFA such as hydroxy-hexenals, neuroketals and EPA-derived isoprostanes are also considered in relation to atherosclerosis. This article is part of a Special Issue entitled "Oxygenated metabolism of PUFA: analysis and biological relevance".

  14. 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 cerebral...... metabolism (from arterial and internal jugular venous O(2), glucose and lactate differences), as well as the middle cerebral artery mean blood velocity (MCA V(mean); transcranial Doppler ultrasound) during a sustained static handgrip contraction at 40% of maximal voluntary contraction (n = 9) and the MCA V...... abolished by glycopyrrolate (P perfusion without affecting the cerebral metabolic rate for oxygen....

  15. Metabolism of biogenic amines in acute cerebral ischemia: Influence of systemic hyperglycemia

    Directory of Open Access Journals (Sweden)

    Milovanović Aleksandar

    2012-01-01

    Full Text Available Dopamine, norepinephrine and serotonin are biogenic amines which are transmitters of the central nervous system. The effects of ischemia on the brain parenchyma depends on many factors, such is the mechanism of blood flow interruption, velocity of the occurring blood flow interruption, duration of an ischemic episode, organization of anatomical structures of the brain blood vessels etc., which all influence the final outcome. During interruption of the brain circulation in experimental or clinical conditions, neurotransmitter metabolism, primarily of biogenic amines, is disturbed. Many researches with various experimental models of complete ischemia reported a decrease in the content of norepinephrine, dopamine and serotonin in the CNS tissue. It was proven that hyperglycemia can drastically increase cerebral injury followed by short-term cerebral ischemia. Considering the fact that biogenic amines (dopamine, norepinephrine and serotonin influence the size of neurologic damage, as well as the fact that in hyperglycemic conditions infarct size (from the morphological aspect is larger relative to normoglycemic status, the intention was to evaluate the role of biogenic amines in occurrence of damage in conditions of hyperglycemia, i.e. in the case of brain apoplexia in diabetics. Analysis of biogenic amines metabolism in states of acute hyperglycemia, as well as analysis of the effects of reversible and irreversible brain ischemia on metabolism of serotonin, dopamine and norepinephrine, showed that acute hyperglycemia slows down serotonin, dopamine and norepinephrine metabolism in the cerebral cortex and n. caudatus. Brain ischemia in normoglycemic animals by itself has no influence on biogenic amines metabolism, but the effect of ischemia becomes apparent during reperfusion. In recirculation, which corresponds to the occurrences in penumbra, release of biogenic amines is uncontrolled and increased. Brain ischemia in acute hyperglycemic animals

  16. Neurodynamics of abnormalities in cerebral metabolism and structure in schizophrenia.

    Science.gov (United States)

    Waddington, J L

    1993-01-01

    Much evidence points to the importance of intrauterine events in the etiology of schizophrenia and suggests a complex interplay between dysfunctional and intact neurons in the pathophysiology of the disorder. This article contrasts what is known of the topographies of metabolic and structural brain abnormalities in schizophrenia at differing stages of the illness. From these contrasts, a schema is elaborated by which subtle neurodevelopmental perturbation in early to middle gestation might give rise to functional and structural abnormalities that ultimately release the diagnostic symptoms of schizophrenia. An interaction between those mechanisms mediating the expression of psychosis and the initially subtle stages of normal aging is posited to act on the substrate of a brain that is already developmentally compromised. Such a process might masquerade as "progression" in the absence of any active disease directly attributable to the original etiological event.

  17. Liposome-encapsulated hemoglobin reduces the size of cerebral infarction in rats: effect of oxygen affinity.

    Science.gov (United States)

    Fukumoto, Dai; Kawaguchi, Akira T; Haida, Munetaka; Yamano, Mariko; Ogata, Yoshitaka; Tsukada, Hideo

    2009-02-01

    Liposome-encapsulated hemoglobin (LEH) with a low oxygen affinity (l-LEH, P(50) = 45 mm Hg) was found to be protective in the rodent and primate models of ischemic stroke. This study investigated the role of LEH with a high O(2) affinity (h-LEH, P(50) = 10 mm Hg) in its protective effect on brain ischemia. The extent of cerebral infarction was determined 24 h after photochemically induced thrombosis of the middle cerebral artery from the integrated area of infarction detected by triphenyltetrazolium chloride staining in rats receiving various doses of h-LEH as well as l-LEH. Both h-LEH and l-LEH significantly reduced the extent of cortical infarction. h-LEH remained protective at a lower concentration (minimal effective dose [MED]: 0.08 mL/kg) than l-LEH (MED: 2 mL/kg) in the cortex. h-LEH reduced the infarction extent in basal ganglia as well (MED: 0.4 mL/kg), whereas l-LEH provided no significant protection. h-LEH provided better protection than l-LEH. The protective effect of both high- and low-affinity LEH may suggest the importance of its small particle size (230 nm) as compared to red blood cells. The superiority of h-LEH over l-LEH supports an optimal O(2) delivery to the ischemic penumbra as the mechanism of action in protecting against brain ischemia and reperfusion.

  18. 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.

  19. ADRB2 gly16gly Genotype, Cardiac Output, and Cerebral Oxygenation in Patients Undergoing Anesthesia for Abdominal Aortic Aneurysm Surgery

    DEFF Research Database (Denmark)

    Staalso, Jonatan Myrup; Rokamp, Kim Zillo; Olesen, Niels D.

    2016-01-01

    BACKGROUND: Gly16arg polymorphism of the adrenergic [beta]2-receptor is associated with the elevated cardiac output (Q) in healthy gly16-homozygotic subjects. We questioned whether this polymorphism also affects Q and regional cerebral oxygen saturation (SCO2) during anesthesia in vascular surgic...

  20. Cerebral oxygenation and processed EEG response to clamping and shunting during carotid endarterectomy under general anesthesia.

    Science.gov (United States)

    Perez, William; Dukatz, Christopher; El-Dalati, Sami; Duncan, James; Abdel-Rasoul, Mahmoud; Springer, Andrew; Go, Michael R; Dzwonczyk, Roger

    2015-12-01

    Clamping and shunting during carotid endarterectomy (CEA) surgery causes changes in cerebral blood flow. The purpose of this study was to assess and compare, side by side, the cerebral oxygenation (rSO2) and processed electroencephalogram (EEG) response bilaterally to carotid artery clamping and shunting in patients undergoing CEA under general anesthesia. With institutional approval and written informed consent, patients undergoing CEA under general anesthesia and routine carotid artery shunting were recorded bilaterally, simultaneously and continuously with an rSO2 and processed EEG monitor. The response of the monitors during carotid artery clamping and shunting were assessed and compared between monitors and bilaterally within each monitor. Sixty-nine patients were included in the study. At clamping the surgical-side and contralateral-side rSO2 dropped significantly below the baseline incision value (-17.6 and -9.4% respectively). After shunting, the contralateral-side rSO2 returned to baseline while the surgical-side rSO2 remained significantly below baseline (-9.0%) until the shunt was removed following surgery. At clamping the surgical-side and contralateral-side processed EEG also dropped below baseline (-19.9 and -20.6% respectively). However, following shunt activation, the processed EEG returned bilaterally to baseline. During the course of this research, we found the rSO2 monitor to be clinically more robust (4.4% failure rate) than the processed EEG monitor (20.0% failure rate). There was no correlation between the rSO2 or processed EEG changes that occurred immediately after clamping and the degree of surgical side stenosis measured pre-operatively. Both rSO2 and processed EEG respond to clamping and shunting during CEA. Cerebral oximetry discriminates between the surgical and contralateral side during surgery. The rSO2 monitor is more reliable in the real-world clinical setting. Future studies should focus on developing algorithms based on these

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

    Institute of Scientific and Technical Information of China (English)

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

    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 metabolic profiling in rabbits with ASCP

  2. Effect of desipramine and fluoxetine on energy metabolism of cerebral mitochondria.

    Science.gov (United States)

    Villa, Roberto Federico; Ferrari, Federica; Gorini, Antonella; Brunello, Nicoletta; Tascedda, Fabio

    2016-08-25

    Brain bioenergetic abnormalities in mood disorders were detected by neuroimaging in vivo studies in humans. Because of the increasing importance of mitochondrial pathogenetic hypothesis of Depression, in this study the effects of sub-chronic treatment (21days) with desipramine (15mg/kg) and fluoxetine (10mg/kg) were evaluated on brain energy metabolism. On mitochondria in vivo located in neuronal soma (somatic) and on mitochondria of synapses (synaptic), the catalytic activities of regulatory enzymes of mitochondrial energy-yielding metabolic pathways were assayed. Antidepressants in vivo treatment modified the activities of selected enzymes of different mitochondria, leading to metabolic modifications in the energy metabolism of brain cortex: (a) the enhancement of cytochrome oxidase activity on somatic mitochondria; (b) the decrease of malate, succinate dehydrogenase and glutamate-pyruvate transaminase activities of synaptic mitochondria; (c) the selective effect of fluoxetine on enzymes related to glutamate metabolism. These results overcome the conflicting data so far obtained with antidepressants on brain energy metabolism, because the enzymatic analyses were made on mitochondria with diversified neuronal in vivo localization, i.e. on somatic and synaptic. This research is the first investigation on the pharmacodynamics of antidepressants studied at subcellular level, in the perspective of (i) assessing the role of energy metabolism of cerebral mitochondria in animal models of mood disorders, and (ii) highlighting new therapeutical strategies for antidepressants targeting brain bioenergetics.

  3. A longitudinal study of cerebral glucose metabolism, MRI, and disability in patients with MS

    DEFF Research Database (Denmark)

    Blinkenberg, M; Jensen, C.V.; Holm, S;

    1999-01-01

    in longitudinal studies of MS patients, but little is known about the associated changes in cerebral neural function. METHODS: The authors studied 10 patients with clinically definite MS who underwent serial measurements of CMRglc, MRI T2-weighted total lesion area (TLA), and clinical evaluation of disability...... (Expanded Disability Status Scale [EDSS]) over a period of approximately 2 years (three examinations). CMRglc was calculated using PET and 18-fluorodeoxyglucose (FDG). RESULTS: The global cortical CMRglc decreased with time (p...OBJECTIVE: To study the time-related changes in cerebral metabolic rate of glucose (CMRglc) in MS patients and to correlate these with changes in MRI lesion load and disability. BACKGROUND: Measurements of MRI lesion load and neurologic disability are used widely to monitor disease progression...

  4. Cerebral blood flow and metabolic abnormalities in Alzheimer's disease

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Hiroshi [National Center of Neurology and Psychiatry, Kodaira, Tokyo (Japan). National Center Hospital for Mental, Nervous, and Muscular Disorders

    2001-04-01

    In this review I summarize observations of PET and SPECT studies about cerebral blood flow and metabolic abnormalities in Alzheimer's disease (AD). In very early AD flow or metabolism reduces first in the posterior cingulate gyrus and precuneus. This reduction may arise from functional deafferentation caused by primary neural degeneration in the remote area of the entorhinal cortex that is the first to be pathologically affected in AD. Then medial temporal structures and parietotemporal association cortex show flow or metabolic reduction as disease processes. The reason why flow or metabolism in medial temporal structures shows delay in starting to reduce in spite of the earliest pathological affection remains to be elucidated. It is likely that anterior cingulate gyrus is functionally involved, since attention is the first non-memory domain to be affected, before deficits in language and visuospatial functions. However few reports have described involvement in the anterior cingulate gyrus. Relationship between cerebral blood flow or metabolism and apolipoprotein E (APOE) genotype has been investigated. Especially, the APOE{epsilon}4 allele has been reported to increase risk and to lower onset age as a function of the inherited dose of the {epsilon}4 allele. Reduction of flow or metabolism in the posterior cingulate gyrus and precuneus has been reported even in presymptomatic nondemented subjects who were cognitively normal and had at least a single {epsilon}4 allele. On the contrary the relation of {epsilon}4 allele to the progression rate of AD has been controversial from neuroimaging approaches. PET and SPECT imaging has become to be quite useful for assessing therapeutical effects of newly introduced treatment for AD. Recent investigations observed significant regional flow increase after donepezil hydrochloride treatment. Most of these observations have been made by applying computer assisted analysis of three-dimensional stereotactic surface projection

  5. Initial clinical experience with near-infrared spectroscopy in assessing cerebral tissue oxygen saturation in cerebral vasospasm before and after intra-arterial verapamil injection.

    Science.gov (United States)

    Meng, Lingzhong; Settecase, Fabio; Xiao, Jifang; Yu, Zhaoxia; Flexman, Alana M; Higashida, Randall T

    2016-04-01

    Cerebral vasospasm is a devastating complication after subarachnoid hemorrhage. The use of cerebral tissue oxygen saturation (SctO2) to non-invasively assess changes in cerebral tissue perfusion induced by intra-arterial (IA) verapamil treatment has not been described to our knowledge. A total of 21 consecutive post-craniotomy patients scheduled for possible IA verapamil treatment of cerebral vasospasm were recruited. The effect of IA verapamil injection on SctO2 being continuously monitored on both the left and right forehead was investigated. Comparisons between changes in SctO2 monitored on the ipsilateral and contralateral forehead in relationship to the side of internal carotid artery (ICA) injection were performed. A total of 47 IA verapamil injections (15 left ICA, 18 right ICA, and 14 vertebral artery injections) during 18 neurointerventional procedures in 13 patients were analyzed. IA verapamil administration led to both increases and decreases in SctO2. Changes in SctO2 ipsilateral to the ICA injection side were more pronounced (p=0.02 and 0.07 for left and right ICA injections, respectively) and favored compared to contralateral SctO2 changes. We were unable to obtain reliable measurements on the side ipsilateral to the craniotomy during four procedures in three patients, presumably secondary to pneumocephalus. The local cerebral vasodilating effect of IA verapamil injection is suggested by the differential changes in SctO2 ipsilateral and contralateral to the ICA injection side. The inconsistent changes in SctO2 and the limitations of applying cerebral oximetry in this patient population needs to be recognized.

  6. Genetic enhancement of microsomal epoxide hydrolase improves metabolic detoxification but impairs cerebral blood flow regulation.

    Science.gov (United States)

    Marowsky, Anne; Haenel, Karen; Bockamp, Ernesto; Heck, Rosario; Rutishauser, Sibylle; Mule, Nandkishor; Kindler, Diana; Rudin, Markus; Arand, Michael

    2016-12-01

    Microsomal epoxide hydrolase (mEH) is a detoxifying enzyme for xenobiotic compounds. Enzymatic activity of mEH can be greatly increased by a point mutation, leading to an E404D amino acid exchange in its catalytic triad. Surprisingly, this variant is not found in any vertebrate species, despite the obvious advantage of accelerated detoxification. We hypothesized that this evolutionary avoidance is due to the fact that the mEH plays a dualistic role in detoxification and control of endogenous vascular signaling molecules. To test this, we generated mEH E404D mice and assessed them for detoxification capacity and vascular dynamics. In liver microsomes from these mice, turnover of the xenobiotic compound phenanthrene-9,10-oxide was four times faster compared to WT liver microsomes, confirming accelerated detoxification. mEH E404D animals also showed faster metabolization of a specific class of endogenous eicosanoids, arachidonic acid-derived epoxyeicosatrienoic acids (EETs) to dihydroxyeicosatrienoic acids (DHETs). Significantly higher DHETs/EETs ratios were found in mEH E404D liver, urine, plasma, brain and cerebral endothelial cells compared to WT controls, suggesting a broad impact of the mEH mutant on endogenous EETs metabolism. Because EETs are strong vasodilators in cerebral vasculature, hemodynamics were assessed in mEH E404D and WT cerebral cortex and hippocampus using cerebral blood volume (CBV)-based functional magnetic resonance imaging (fMRI). Basal CBV0 levels were similar between mEH E404D and control mice in both brain areas. But vascular reactivity and vasodilation in response to the vasodilatory drug acetazolamide were reduced in mEH E404D forebrain compared to WT controls by factor 3 and 2.6, respectively. These results demonstrate a critical role for mEH E404D in vasodynamics and suggest that deregulation of endogenous signaling pathways is the undesirable gain of function associated with the E404D variant.

  7. Cerebral metabolic changes in neurologically presymptomatic patients undergoing haemodialysis: in vivo proton MR spectroscopic findings

    Energy Technology Data Exchange (ETDEWEB)

    Chiu, Ming-Lun; Chiang, I. Chan [Kaohsiung Medical University Hospital, Department of Medical Imaging (China); Li, Chun-Wei [Kaohsiung Medical University, Department of Medical Imaging and Radiological Sciences, College of Health Science (China); Chang, Jer-Ming [Kaohsiung Medical University, Department of Internal Medicine, Kaohsiung Hsiao-Kang Municipal Hospital (China); Kaohsiung Medical University, Department of Nephrology, School of Medicine, College of Medicine (China); Ko, Chih-Hung [Kaohsiung Medical University, Department of Psychiatry, School of Medicine, College of Medicine (China); Kaohsiung Medical University Hospital, Department of Psychiatry (China); Chuang, Hung-Yi [Kaohsiung Medical University, Faculty of Public Health, College of Health Science (China); Kaohsiung Medical University Hospital, Department of Environmental and Occupational Medicine (China); Sheu, Reu-Sheng [Kaohsiung Medical University, Department of Radiology, Kaohsiung Municipal Hsiao-Kang Hospital (China); Kaohsiung Medical University, Department of Radiology, Faculty of Medicine, College of Medicine (China); Lee, Chen-Chang [Kaohsiung Medical University, Department of Medical Imaging and Radiological Sciences, College of Health Science (China); Kaohsiung Medical Centre, Department of Radiology, Chang Gung Memorial Hospital (China); Hsieh, Tsyh-Jyi [Kaohsiung Medical University Hospital, Department of Medical Imaging (China); Kaohsiung Medical University, Department of Radiology, Faculty of Medicine, College of Medicine (China); Kaohsiung Municipal Ta-Tung Hospital, Department of Medical Imaging (China)

    2010-06-15

    To prospectively investigate and detect early cerebral metabolic changes in patients with end-stage renal disease (ESRD) by using in vivo proton MR spectroscopy (MRS). We enrolled 32 patients with ESRD and 32 healthy controls between the ages of 26 and 50 years. Short echo time single-voxel proton MRS was acquired from volumes of interest (VOIs) located in the frontal grey and white matter, temporal white matter and basal ganglia. The choline/phospatidylcholine (Cho), myo-inositol (mI), N-acetylaspartate (NAA) and total creatine (tCr) peaks were measured and the metabolic ratios with respect to tCr were calculated. In the ESRD group, significant elevations of the Cho/tCr and mI/tCr ratios were observed for the frontal grey matter, frontal white matter, temporal white matter and basal ganglia as compared with controls. There was no significant difference in the NAA/tCr ratios at all VOIs between the ESRD patients and the healthy controls. Proton MRS is a useful and non-invasive imaging tool for the detection of early cerebral metabolic changes in neurologically presymptomatic ESRD patients. (orig.)

  8. Regional cerebral glucose metabolism in frontotemporal dementia: a study with FDG PET

    Energy Technology Data Exchange (ETDEWEB)

    Cho, S. S.; Jeong, J.; Kang, S. J.; Na, D. L.; Choe, Y. S.; Lee, K. H.; Choi, Y.; Kim, B. T.; Kim, S. E. [Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2002-07-01

    Frontotemporal dementia (FTD) is a common cause of presenile dementia. We investigated the regional cerebral glucose metabolic impairments in patients with FTD using FDG PET. We analysed the regional metabolic patterns on FDG PET images obtained from 30 patients with FTD and age- and sex-matched 15 patients with Alzheimers disease (AD) and 11 healthy subjects using SPM99. We also compared the inter-hemispheric metabolic asymmetry among the three groups by counting the total metabolic activity of each hemisphere and computing asymmetry index (AL) between hemispheres. The hypometabolic brain regions in FTD patients compared with healthy controls were as follows: superior middle and medial frontal lobules, superior and middle temporal lobules, anterior and posterior cingulate gyri, uncus, insula, lateral globus pallidus and thalamus. The regions with decreased metabolism in FTD patients compared with AD patients were as follows: superior, inferior and medial frontal lobules, anterior cingulate gyrus, and caudate nucleus. Twenty-five (83%) out of the 30 FTD patients had AI values that was beyond the 95% confidence interval of the AI values obtained from healthy controls; 10 patients had hypometabolism more severe on the right and 15 patients had the opposite pattern. In comparison, 10 (67%) out of the 15 AD patients had asymmetric metabolism. Our SPM analysis of FDG PET revealed additional areas of decreased metabolism in FTD patients compared with prior studies using the ROI method, involving frontal, temporal, cingulate gyrus, corpus callosum, uncus, insula, and some subcortical areas. The inter-hemispheric metabolic asymmetry was common in FTD patients, which can be another metabolic feature that helps differentiate FTD from AD.

  9. EFFECT OF ACUPUNCTURE STIMULATION AT SANYINJIAO (SP 6) ON CEREBRAL GLUCOSE METABOLISM IN DYSMENORRHEA PATIENTS

    Institute of Scientific and Technical Information of China (English)

    GONG Ping; ZHANG Ming-min; JIANG Li-ming; WU Zhi-jian; WANG Wei; HUANG Guang-ying

    2006-01-01

    Objective: To study the central mechanism of acupuncture stimulation of Sanyinjiao ( 三阴交 SP6) in relieving dysmenorrhea. Methods: A total of 6 dysmenorrhea volunteer patients were subjected into this study. On the first positron emission tomography (PET) scan examination, they were assigned to pseudoacupuncture group by using the acupuncture needle just to prick the skin of Sanyinjiao (SP 6); while on the second PET scans, they were assigned to acupuncture group by inserting the needle into the same acupoint.18F fluorodeoxyglucose (18F-FDG) PET of the whole brain was performed during pseudo-acupuncture and real acupuncture of Sanyinjiao (SP 6). The acquired PET data were analyzed by using statistical parametric mapping (SPM) software to determine changes of glucose metabolism in different cerebral regions. The patient's pain intensity was rated by using 0- 10 numerical pain intensity scale. Results: After pseudo-acupuncture stimulation of Sanyinjiao (SP 6), no significant changes were found in the pain intensity ( P >0.05), while after real-acupuncture stimulation, the pain intensity declined significantly (P < 0.01 ). Following acupuncture of the right Sanyinjiao (SP 6), multiple cerebral regions involving pain were activated (increase of glucose metabolism), including ipsilateral lenticular nucleus (globus pallidus, putamen), ipsilateral cerebellum and insular lobe, bilateral dorsal thalamus, ipsilateral paracentral lobule, bilateral amygdaloid bodies, contralateral substantia nigra of the midbrain, bilateral second somatosensory (S Ⅱ ) areas, ispsilateral hippocampal gyrus, frontal part of the ipsilateral cingulated gyrus, and bilateral mammary bodies of the hypothalamus. In addition, fewer regions of the cerebral cortex responded with decrease of the glucose metabolism after real acupuncture.

  10. Comparison of Cerebral Metabolism between Pig Ventricular Fibrillation and Asphyxial Cardiac Arrest Models

    Institute of Scientific and Technical Information of China (English)

    Yi Zhang; Chun-Sheng Li; Cai-Jun Wu; Jun Yang; Chen-Chen Hang

    2015-01-01

    Background:Morbidity and mortality after resuscitation largely depend on the recovery of brain function.Ventricular fibrillation cardiac arrest (VFCA) and asphyxial cardiac arrest (ACA) are the two most prevalent causes of sudden cardiac death.Up to now,most studies have focused on VFCA.However,results from the two models have been largely variable.So,it is necessary to characterize the features of postresuscitation cerebral metabolism of both models.Methods:Forty-four Wuzhishan miniature inbred pigs were randomly divided into three groups:18 for VFCA group,ACA group,respectively,and other 8 for sham-operated group (SHAM).VFCA was induced by programmed electric stimulation,andACA was induced by endotracheal tube clamping.After 8 min without treatment,standard cardiopulmonary resuscitation (CPR) was initiated.Following neurological deficit scores (NDS) were evaluated at 24 h after achievement of spontaneous circulation,cerebral metabolism showed as the maximum standardized uptake value (SUVmax) was measured by 18F-fluorodeoxyglucose positron emission tomography/computed tomography.Levels of serum markers of brain injury,neuron specific enolase (NSE),and S100β were quantified with an enzyme-linked immunosorbent assay.Results:Compared with VFCA group,fewer ACA animals achieved restoration of spontaneous circulation (61.1% vs.94.4%,P < 0.01) and survived 24-h after resuscitation (38.9% vs.77.8%,P < 0.01) with worse neurological outcome (NDS:244.3 ± 15.3 vs.168.8 ± 9.71,P < 0.01).The CPR duration of ACA group was longer than that of VFCA group (8.1 ± 1.2 min vs.4.5 ± 1.1 min,P < 0.01).Cerebral energy metabolism showed as SUVmax in ACA was lower than in VFCA (P < 0.05 or P < 0.01).Higher serum biomarkers of brain damage (NSE,S100β) were found inACA than VFCA after resuscitation (P < 0.01).Conclusions:Compared with VFCA,ACA causes more severe cerebral metabolism injuries with less successful resuscitation and worse neurological outcome.

  11. Comparison of Cerebral Metabolism between Pig Ventricular Fibrillation and Asphyxial Cardiac Arrest Models

    Directory of Open Access Journals (Sweden)

    Yi Zhang

    2015-01-01

    Full Text Available Background: Morbidity and mortality after resuscitation largely depend on the recovery of brain function. Ventricular fibrillation cardiac arrest (VFCA and asphyxial cardiac arrest (ACA are the two most prevalent causes of sudden cardiac death. Up to now, most studies have focused on VFCA. However, results from the two models have been largely variable. So, it is necessary to characterize the features of postresuscitation cerebral metabolism of both models. Methods: Forty-four Wuzhishan miniature inbred pigs were randomly divided into three groups: 18 for VFCA group, ACA group, respectively, and other 8 for sham-operated group (SHAM. VFCA was induced by programmed electric stimulation, and ACA was induced by endotracheal tube clamping. After 8 min without treatment, standard cardiopulmonary resuscitation (CPR was initiated. Following neurological deficit scores (NDS were evaluated at 24 h after achievement of spontaneous circulation, cerebral metabolism showed as the maximum standardized uptake value (SUVmax was measured by 18 F-fluorodeoxyglucose positron emission tomography/computed tomography. Levels of serum markers of brain injury, neuron specific enolase (NSE, and S100β were quantified with an enzyme-linked immunosorbent assay. Results: Compared with VFCA group, fewer ACA animals achieved restoration of spontaneous circulation (61.1% vs. 94.4%, P < 0.01 and survived 24-h after resuscitation (38.9% vs. 77.8%, P < 0.01 with worse neurological outcome (NDS: 244.3 ± 15.3 vs. 168.8 ± 9.71, P < 0.01. The CPR duration of ACA group was longer than that of VFCA group (8.1 ± 1.2 min vs. 4.5 ± 1.1 min, P < 0.01. Cerebral energy metabolism showed as SUVmax in ACA was lower than in VFCA (P < 0.05 or P < 0.01. Higher serum biomarkers of brain damage (NSE, S100β were found in ACA than VFCA after resuscitation (P < 0.01. Conclusions: Compared with VFCA, ACA causes more severe cerebral metabolism injuries with less successful resuscitation and worse

  12. Limited Influence of Oxygen on the Evolution of Chemical Diversity in Metabolic Networks

    Directory of Open Access Journals (Sweden)

    Kazuhiro Takemoto

    2013-10-01

    Full Text Available Oxygen is thought to promote species and biomolecule diversity. Previous studies have suggested that oxygen expands metabolic networks by acquiring metabolites with different chemical properties (higher hydrophobicity, for example. However, such conclusions are typically based on biased evaluation, and are therefore non-conclusive. Thus, we re-investigated the effect of oxygen on metabolic evolution using a phylogenetic comparative method and metadata analysis to reduce the bias as much as possible. Notably, we found no difference in metabolic network expansion between aerobes and anaerobes when evaluating phylogenetic relationships. Furthermore, we showed that previous studies have overestimated or underestimated the degrees of differences in the chemical properties (e.g., hydrophobicity between oxic and anoxic metabolites in metabolic networks of unicellular organisms; however, such overestimation was not observed when considering the metabolic networks of multicellular organisms. These findings indicate that the contribution of oxygen to increased chemical diversity in metabolic networks is lower than previously thought; rather, phylogenetic signals and cell-cell communication result in increased chemical diversity. However, this conclusion does not contradict the effect of oxygen on metabolic evolution; instead, it provides a deeper understanding of how oxygen contributes to metabolic evolution despite several limitations in data analysis methods.

  13. Preoperative cerebral metabolic difference related to the outcome of cochlear implantation in prelingually deaf children

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J. H.; Lim, G. C.; Ahn, J. H.; Lee, K. S.; Jeong, J. W.; Kim, J. S. [Asan Medical Center, Seoul (Korea, Republic of)

    2007-07-01

    The outcome of cochlear implantation (CI) has known to be variable. The aim of this study was to evaluate the preoperative regional glucose metabolism difference related to the speech perception outcome after CI in prelingually deaf children. Forty-one prelingually deaf children who underwent CI at age 2{approx}10 years were included. All patients underwent F-18 FDG brain PET within one month before CI and measured speech perception using the institute version of the CID at 2 years after CI. Patients were classified into younger (2{approx}6 years) and older (7{approx}10 years) groups. Each group was also divided into a GOOD (CID scores>80) and a BAD (CID scores<60) subgroup. We assessed regional metabolic difference according to CID scores and age by voxel based analysis (SPM2) comparing normal controls (n =8, 20{approx}30 years). Speech perception was good in 19 (68%) of 28 younger patients and 5 (38%) of 13 older patients after CI. Regional metabolism of both younger and older GOOD subgroup was significantly decreased in right temporal, left cerebellar and right frontal regions compared to normal controls (uncorrected p<0.001). In younger GOOD subgroup, left frontotemporal and both parietal regions showed decreased metabolism and right frontal, left temporal and anterior cingulate regions showed increased metabolism compared to BAD subgroup (uncorrected p<0.005). In younger group, regional metabolism in left superior frontal, right temporal and right occipital regions showed a significant negative correlation with CID scores (uncorrected p<0.005). In older group, the pattern of regional metabolic difference correlated with CID score was not similar to that of younger group. Preoperative regional cerebral metabolism is decreased in several brain regions related to the language in preligually deaf patients and the neuralplasty of younger patients are different according to the outcome of speech perception after CI.

  14. Subcortical cerebral blood flow and metabolic changes elicited by cortical spreading depression in rat

    Energy Technology Data Exchange (ETDEWEB)

    Mraovitch, S.; Calando, Y.; Goadsby, P.J.; Seylaz, J. (Laboratoire de Recherches Cerebrovasculaire, Paris (France))

    1992-06-01

    Changes in cerebral cortical perfusion (CBF{sub LDF}), local cerebral blood flow (lCBF) and local cerebral glucose utilization (lCGU) elicited by unilateral cortical spreading depression (SD) were monitored and measured in separate groups of rats anesthetized with {alpha}-chloralose. CBF{sub LDF} was recorded with laser Doppler flowmetry, while lCBF and lCGU were measured by the quantitative autoradiographic ({sup 14}C)iodoantipyrine and ({sup 14}C)-2-deoxyglucose methods, respectively. SD elicited a wave of hyperemia after a latency of 2 to 3 min followed by an oligemic phase. Ninety minutes following the onset of SD cortical lCBF and lCGU were essentially the same as on the contralateral side and in sham-treated rats. However, alteration in the lCBF and lCGU in upper and lower brainstem persisted. The present results demonstrate that long-lasting cerebrovascular and metabolic alterations take place within the subcortical regions following SD. These regions provide an attractive site to integrate observations in man concerning spreading depression and the aura of migraine with the other features of the syndrome. 19 refs., 2 figs., 1 tab.

  15. New insights into coupling and uncoupling of cerebral blood flow and metabolism in the brain.

    Science.gov (United States)

    Venkat, Poornima; Chopp, Michael; Chen, Jieli

    2016-06-30

    The brain has high metabolic and energy needs and requires continuous cerebral blood flow (CBF), which is facilitated by a tight coupling between neuronal activity, CBF, and metabolism. Upon neuronal activation, there is an increase in energy demand, which is then met by a hemodynamic response that increases CBF. Such regional CBF increase in response to neuronal activation is observed using neuroimaging techniques such as functional magnetic resonance imaging and positron emission tomography. The mechanisms and mediators (eg, nitric oxide, astrocytes, and ion channels) that regulate CBF-metabolism coupling have been extensively studied. The neurovascular unit is a conceptual model encompassing the anatomical and metabolic interactions between the neurons, vascular components, and glial cells in the brain. It is compromised under disease states such as stroke, diabetes, hypertension, dementias, and with aging, all of which trigger a cascade of inflammatory responses that exacerbate brain damage. Hence, tight regulation and maintenance of neurovascular coupling is central for brain homeostasis. This review article also discusses the waste clearance pathways in the brain such as the glymphatic system. The glymphatic system is a functional waste clearance pathway that removes metabolic wastes and neurotoxins from the brain along paravascular channels. Disruption of the glymphatic system burdens the brain with accumulating waste and has been reported in aging as well as several neurological diseases.

  16. Influence of temperature, oxygen and salinity on the metabolism of the European sea bass

    Science.gov (United States)

    Claireaux, G.; Lagardère, J.-P.

    1999-09-01

    Standard (SMR) and routine (RMR) metabolic rates of groups (4 to 5 individuals) of European sea bass ( Dicentrarchus labrax) were measured at combinations of the following factors: temperature (10, 15, 20 and 25°C), oxygenation level (air saturation to 1.5 mg dm -3) and salinity (30, 20, 10 and 5‰). The influence of these environmental conditions on fish metabolic demand was then analysed through ANOVA. At 10, 15, 20 and 25°C, standard metabolic rates were 36, 65, 89, and 91 mg O 2 kg -1 h -1, respectively, while routine oxygen consumptions covered most of the metabolic range accessible. Osmoregulatory costs are linked to metabolic activity through ventilation. This relationship was highlighted by the observed interaction between environmental salinity and temperature. We were, however, unable to detect interactions between salinity and routine metabolic rate, or between salinity and oxygenation level. In order to delineate more precisely the restrictions imposed by water oxygenation on fish metabolic performance we determined the limiting oxygen concentration curves at each experimental temperature. We followed up by modelling the bass active metabolic rate (AMR) and metabolic scope (MS) as functions of both ambient temperature and oxygenation. These mathematical models allowed the characterisation of the controlling and limiting effects of water temperature and oxygen content on the metabolic capacity of the species. Thus, AMR at 10, 15 and 20°C were estimated at 65, 160 and 360 mg O 2 kg -1 h -1, respectively. However, at higher temperature (25°C) AMR dropped slightly (to 340 mg O 2 kg -1 h -1). Bass MS increased by a factor of 9 between 10 and 20°C, but diminished at higher temperatures. The present study contributes to our current understanding of the influences of environmental factors on the metabolism of sea bass and provides a bioenergetic basis for a study of how environmental constraints govern the spatial and temporal distribution pattern of this

  17. Near-infrared spectroscopy assessed cerebral oxygenation during open abdominal aortic aneurysm repair: relation to end-tidal CO2 tension.

    Science.gov (United States)

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

    2016-08-01

    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 ventilation were obtained retrospectively from the anesthetic charts. By clamping the aorta, ScO2 and EtCO2 were kept stable by reducing ventilation (median, -0.8 l min(-1); interquartile range, -1.1 to -0.4; P body is reperfused.

  18. 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.

  19. 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.

  20. Enhanced metabolic capacity of the frontal cerebral cortex after Pavlovian conditioning.

    Science.gov (United States)

    Bruchey, A K; Gonzalez-Lima, F

    2008-03-18

    While Pavlovian conditioning alters stimulus-evoked metabolic activity in the cerebral cortex, less is known about the effects of Pavlovian conditioning on neuronal metabolic capacity. Pavlovian conditioning may increase prefrontal cortical metabolic capacity, as suggested by evidence of changes in cortical synaptic strengths, and evidence for a shift in memory initially processed in subcortical regions to more distributed prefrontal cortical circuits. Quantitative cytochrome oxidase histochemistry was used to measure cumulative changes in brain metabolic capacity associated with both cued and contextual Pavlovian conditioning in rats. The cued conditioned group received tone-foot-shock pairings to elicit a conditioned freezing response to the tone conditioned stimulus, while the contextually conditioned group received pseudorandom tone-foot-shock pairings in an excitatory context. Untrained control group was handled daily, but did not receive any tone presentations or foot shocks. The cued conditioned group had higher cytochrome oxidase activity in the infralimbic and anterior cingulate cortex, and lower cytochrome oxidase activity in dorsal hippocampus than the other two groups. A significant increase in cytochrome oxidase activity was found in anterior cortical areas (medial, dorsal and lateral frontal cortex; agranular insular cortex; lateral and medial orbital cortex and prelimbic cortex) in both conditioned groups, as compared with the untrained control group. In addition, no differences in cytochrome oxidase activity in the somatosensory regions and the amygdala were detected among all groups. The findings indicate that cued and contextual Pavlovian conditioning induces sustained increases in frontal cortical neuronal metabolic demand resulting in regional enhancement in the metabolic capacity of anterior cortical regions. Enhanced metabolic capacity of these anterior cortical areas after Pavlovian conditioning suggests that the frontal cortex may play a

  1. RATIONALE FOR PREVENTION OF CARDIO-CEREBRAL COMPLICATIONS IN THE METABOLIC SYNDROME BASED ON MATHEMATICAL FORECASTING TECHNIQUES

    Directory of Open Access Journals (Sweden)

    S. V. Chernavskii

    2011-01-01

    Full Text Available Objective — to study prevention of cardio-cerebral complications of metabolic syndrome on the basis of mathematical methods of forecasting.Subjects and methods. A discriminant analysis of clinical and instrumental data of patients with MS.Results of this study allow the early (prenosological stages of the metabolic syndrome using the linear discriminant equations to predict thedevelopment of myocardial infarction up to 89.3 %, stroke — up to 87.8 %.Conclusion. The diagnostic and treatment algorithms developed based on the stratification of cardiovascular risk index, allow us to give sound recommendations for targeted prevention of cardio-cerebral complications.

  2. Effect of head rotation during surgery in the prone position on regional cerebral oxygen saturation

    DEFF Research Database (Denmark)

    Andersen, Johnny Dohn Holmgren; Baake, Gerben; Wiis, Julie Therese;

    2014-01-01

    BACKGROUND: Near-infrared spectroscopy (NIRS) has been used to study regional cerebral blood oxygen saturation (rScO2) in patients in the prone position. OBJECTIVES: We aimed to test the hypothesis that head rotation more than 45° would affect the rScO2. DESIGN: A prospective, controlled, single......-state anaesthesia with the head in the neutral position, rotated left, rotated right and returned to the neutral position. Each series consisted of three measurements: resting on the head support, during head lift (to relieve pressure on the tissue at the sensors) and returned to rest on the head support. MAIN...... OUTCOME MEASURES: The differences in rScO2 between the neutral and the turned head positions. RESULTS: For both left and right sensors, the median differences in rScO2 between neutral and left or right positions were between 0 and -1 with the head up (P = 0.14 to 0.84). The median differences...

  3. Wavelet analysis of cerebral oxygenation oscillations in the screening of Moyamoya disease.

    Science.gov (United States)

    He, Ying; Jiang, Pengjun; Han, Shanshan; Wang, Rong; Li, Yue; Teng, Yichao; Gao, Tianxin

    2014-01-01

    Near-infrared spectroscopy (NIRS) was used to investigate the cerebral oxygenation of Moyamoya and healthy subjects. Continuous recordings of NIRS signals for 20 min (20 min signals) were obtained from 17 healthy subjects (age: 37.4 ± 11.3) and 17 Moyamoya subjects (age: 40.1 ± 11.2). Spectral analysis based on wavelet transformation identified five frequency intervals (I, 0.0095 Hz to 0.02 Hz; II, 0.02 Hz to 0.06 Hz; III, 0.06 Hz to 0.15 Hz; IV, 0.15 Hz to 0.40 Hz; and V, 0.40 Hz to 2.00 Hz) in the 20 min signals and three frequency intervals (III, 0.06 Hz to 0.15 Hz; IV, 0.15 Hz to 0.40 Hz; and V, 0.40 Hz to 2.00 Hz) in the 3 min signals (the first 3 min signals were continuously extracted from the 20 min signals). Significant differences (p Moyamoya disease. As a potential screening method for Moyamoya disease, the simple threshold method exhibited 73.5% accuracy.

  4. Neurotrophin-3 promotes cell death induced in cerebral ischemia, oxygen-glucose deprivation, and oxidative stress: possible involvement of oxygen free radicals.

    Science.gov (United States)

    Bates, Brian; Hirt, Lorenz; Thomas, Sunu S; Akbarian, Schahram; Le, Dean; Amin-Hanjani, Sepideh; Whalen, Michael; Jaenisch, Rudolf; Moskowitz, Michael A

    2002-02-01

    To explore the role of neurotrophin-3 (NT-3) during cerebral ischemia, NT-3-deficient brains were subjected to transient focal ischemia. Conditional mutant brains produced undetectable amounts of NT-3 mRNA, whereas the expression of the neurotrophin, BDNF, the NT-3 receptor, TrkC, and the nonselective, low-affinity neurotrophin receptor p75NTR, were comparable to wild-type. Baseline absolute blood flow, vascular and neuroanatomical features, as well as physiological measurements were also indistinguishable from wild-type. Interestingly, the absence of NT-3 led to a significantly decreased infarct volume 23 h after middle cerebral artery occlusion. Consistent with this, the addition of NT-3 to primary cortical cell cultures exacerbated neuronal death caused by oxygen-glucose deprivation. Coincubation with the oxygen free radical chelator, trolox, diminished potentiation of neuronal death. NT-3 also enhanced neuronal cell death and the production of reactive oxygen species caused by oxidative damage inducing agents. We conclude that endogenous NT-3 enhanced neuronal injury during acute stroke, possible by increasing oxygen-radical mediated cell death.

  5. EFFECT OF ELECTRO0-SCALP ACUPUNCTURE ON GLUCOSE METABOLISM OF THE CEREBRAL REGIONS INVOLVING MENTAL ACTIVITY IN HEAL THY PEOPLE

    Institute of Scientific and Technical Information of China (English)

    HUANG Yong(黄泳); Win Moe Htut; LI Dong-jiang(李东江); TANG An-wu(唐安戊); LI Qiu-shi(李求实)

    2004-01-01

    Objective: To observe the effect of electro-scalp acupuncture on glucose metabolism of cerebral regions involving mental activity in healthy people. Methods: A total of 6 cases of volunteer healthy subjects (3 males and 3 females) ranging in age from 22 to 36 years were subjected to this study. Changes of cerebral glucose metabolism before and after electro-scalp acupuncture were observed by using positron emission tomography (PET) and semi-quantifying analysis method. Electro-scalp acupuncture stimulation (50 Hz, 2 mA) of Middle Line of Vertex (Dingzhongxian,顶中线,MS5), Middle Line of Forehead (Ezhongxian, 额中线,MS1) and bilateral Lateral Line 1 of Forehead (Epangyixian,额旁一线,MS2) was administered for 30 minutes. Then cerebral regions of interest (ROIs) were chosen and their average glucose metabolism levels (radioactivity of 18 fluorine deoxyglucose ) were analyzed. Results:After administration of electro-scalp acupuncture, the glucose metabolism levels in bilateral frontal lobes and bilateral caudate nuclei, left cingulate gyrus and right cerebellum increased significantly in comparison with those of pre-stimulation (P<0.05). Conclusion:Electro-scalp acupuncture of MS1, MS2 and MS5 can increase the glucose metabolism of certain cerebral regions involving in mental activity in healthy subjects.

  6. Metabolic Adaptations of Azospirillum brasilense to Oxygen Stress by Cell-to-Cell Clumping and Flocculation

    Science.gov (United States)

    Bible, Amber N.; Khalsa-Moyers, Gurusahai K.; Mukherjee, Tanmoy; Green, Calvin S.; Mishra, Priyanka; Purcell, Alicia; Aksenova, Anastasia; Hurst, Gregory B.

    2015-01-01

    The ability of bacteria to monitor their metabolism and adjust their behavior accordingly is critical to maintain competitiveness in the environment. The motile microaerophilic bacterium Azospirillum brasilense navigates oxygen gradients by aerotaxis in order to locate low oxygen concentrations that can support metabolism. When cells are exposed to elevated levels of oxygen in their surroundings, motile A. brasilense cells implement an alternative response to aerotaxis and form transient clumps by cell-to-cell interactions. Clumping was suggested to represent a behavior protecting motile cells from transiently elevated levels of aeration. Using the proteomics of wild-type and mutant strains affected in the extent of their clumping abilities, we show that cell-to-cell clumping represents a metabolic scavenging strategy that likely prepares the cells for further metabolic stresses. Analysis of mutants affected in carbon or nitrogen metabolism confirmed this assumption. The metabolic changes experienced as clumping progresses prime cells for flocculation, a morphological and metabolic shift of cells triggered under elevated-aeration conditions and nitrogen limitation. The analysis of various mutants during clumping and flocculation characterized an ordered set of changes in cell envelope properties accompanying the metabolic changes. These data also identify clumping and early flocculation to be behaviors compatible with the expression of nitrogen fixation genes, despite the elevated-aeration conditions. Cell-to-cell clumping may thus license diazotrophy to microaerophilic A. brasilense cells under elevated oxygen conditions and prime them for long-term survival via flocculation if metabolic stress persists. PMID:26407887

  7. Metabolic adaptations of Azospirillum brasilense to oxygen stress by cell-to-cell clumping and flocculation.

    Science.gov (United States)

    Bible, Amber N; Khalsa-Moyers, Gurusahai K; Mukherjee, Tanmoy; Green, Calvin S; Mishra, Priyanka; Purcell, Alicia; Aksenova, Anastasia; Hurst, Gregory B; Alexandre, Gladys

    2015-12-01

    The ability of bacteria to monitor their metabolism and adjust their behavior accordingly is critical to maintain competitiveness in the environment. The motile microaerophilic bacterium Azospirillum brasilense navigates oxygen gradients by aerotaxis in order to locate low oxygen concentrations that can support metabolism. When cells are exposed to elevated levels of oxygen in their surroundings, motile A. brasilense cells implement an alternative response to aerotaxis and form transient clumps by cell-to-cell interactions. Clumping was suggested to represent a behavior protecting motile cells from transiently elevated levels of aeration. Using the proteomics of wild-type and mutant strains affected in the extent of their clumping abilities, we show that cell-to-cell clumping represents a metabolic scavenging strategy that likely prepares the cells for further metabolic stresses. Analysis of mutants affected in carbon or nitrogen metabolism confirmed this assumption. The metabolic changes experienced as clumping progresses prime cells for flocculation, a morphological and metabolic shift of cells triggered under elevated-aeration conditions and nitrogen limitation. The analysis of various mutants during clumping and flocculation characterized an ordered set of changes in cell envelope properties accompanying the metabolic changes. These data also identify clumping and early flocculation to be behaviors compatible with the expression of nitrogen fixation genes, despite the elevated-aeration conditions. Cell-to-cell clumping may thus license diazotrophy to microaerophilic A. brasilense cells under elevated oxygen conditions and prime them for long-term survival via flocculation if metabolic stress persists.

  8. Early cerebral hemodynamic, metabolic and histological changes in hypoxic-ischemic fetal lambs during postnatal life

    Directory of Open Access Journals (Sweden)

    Carmen eRey-Santano

    2011-09-01

    Full Text Available The hemodynamic, metabolic and biochemical changes produce during transition from fetal to neonatal life could be aggravated if asphyctic event occur during fetal life. The aim of the study was to examine the regional cerebral blood flow (RCBF, histological changes, and cerebral brain metabolism in preterm lambs, and to analyze the role of oxidative stress for the first hours of postnatal life following severe fetal asphyxia. 18 chronically instrumented fetal lambs were assigned to: hypoxic-ischemic group, following fetal asphyxia animals were delivered and maintained on intermittent-positive-pressure-ventilation for 3 hours, and non-injured animals that were managed similarly to the previous group and used as control group. During hypoxic-ischemic insult, injured group developed acidosis, hypoxia, hypercapnia, latacidaemia and tachycardia in comparison to control group, without hypotension. Intermittent-positive-pressure-ventilation transiently improved gas exchange and cardiovascular parameters. After HI injury and during ventilation-support, the increased RCBF in inner zones was maintained for hypoxic-ischemic group, but cortical flow did not exhibit differences compared to the control group. Also, the increase of TUNEL positive cells (apoptosis and antioxidant enzymes, and decrease of ATP reserves was significantly higher in the brain regions where the RCBF were not increased.In conclusion, early metabolic, histological and hemodynamic changes involved in brain damage have been intensively investigated and reported in premature asphyctic lambs for the first 3 hours of postnatal life. Those changes have been described in human neonates, so our model could be useful to test the security and the effectiveness of different neuroprotective or ventilatory strategies when are applied in the first hours after fetal hypoxic-ischemic injury.

  9. Cerebral hemodynamics: concepts of clinical importance

    Directory of Open Access Journals (Sweden)

    Edson Bor-Seng-Shu

    2012-05-01

    Full Text Available Cerebral hemodynamics and metabolism are frequently impaired in a wide range of neurological diseases, including traumatic brain injury and stroke, with several pathophysiological mechanisms of injury. The resultant uncoupling of cerebral blood flow and metabolism can trigger secondary brain lesions, particularly in early phases, consequently worsening the patient's outcome. Cerebral blood flow regulation is influenced by blood gas content, blood viscosity, body temperature, cardiac output, altitude, cerebrovascular autoregulation, and neurovascular coupling, mediated by chemical agents such as nitric oxide (NO, carbon monoxide (CO, eicosanoid products, oxygen-derived free radicals, endothelins, K+, H+, and adenosine. A better understanding of these factors is valuable for the management of neurocritical care patients. The assessment of both cerebral hemodynamics and metabolism in the acute phase of neurocritical care conditions may contribute to a more effective planning of therapeutic strategies for reducing secondary brain lesions. In this review, the authors have discussed concepts of cerebral hemodynamics, considering aspects of clinical importance.

  10. Dehydration accelerates reductions in cerebral blood flow during prolonged exercise in the heat without compromising brain metabolism

    DEFF Research Database (Denmark)

    Trangmar, Steven J; Chiesa, Scott T; Llodio, Iñaki

    2015-01-01

    Dehydration hastens the decline in cerebral blood flow (CBF) during incremental exercise, whereas the cerebral metabolic rate for O2 (CMRO2 ) is preserved. It remains unknown whether CMRO2 is also maintained during prolonged exercise in the heat and whether an eventual decline in CBF is coupled...... were assessed with dehydration to evaluate CMRO2 . In study 2, in 8 male subjects, middle cerebral artery blood velocity was measured during prolonged exercise to exhaustion in both dehydrated and euhydrated states. After a rise at the onset of exercise, internal carotid artery flow declined...... nonfatiguing exercise. During exhaustive exercise, however, euhydration delayed but did not prevent the decline in cerebral perfusion. In conclusion, during prolonged exercise in the heat, dehydration accelerates the decline in CBF without affecting CMRO2 and also restricts extracranial perfusion. Thus...

  11. Effects of modified chest-up Trendelenburg position on cerebral oxygen metabolism and early postoperative cognitive function in elderly patients undergoing laparoscopic radical resection of the colorectal carcinoma%改良抬胸Trendelenburg位对腹腔镜结直肠癌根治术老年患者脑氧代谢和早期术后认知功能的影响

    Institute of Scientific and Technical Information of China (English)

    施锋; 李金宝; 邓小明; 许波

    2016-01-01

    Objective To study the effects of modified chest-up Trendelenburg position on cerebral oxygen metabolism and early postoperative cognitive function in elderly patients undergoing laparoscopic radical resection of colorectal carcinoma.Methods Eighty ASA Ⅰ or Ⅱ patients,60-82 years old,weighing 44-69 kg,scheduled for elective laparoscopic radical resection of colorectal carcinoma,were randomly divided into 2 groups (n=40):group M,patients in chest-up position using custom-made posture cushions,group T,patients in conventional Trendelenburg position.Blood samples were simultaneously taken from radial artery and jugular bulb at 5 min after regular general anesthesia induction in supine position (T1),immediately after pneumoperitoneum in modified Trendelenburg position or Trendelenburg position(T2),at 30 min (T3),60 min(T4),90 min(T5) after pneumoperitoneum,and at 15 min after deflation in horizon position (T6).The values of blood gas,blood glucose,lactate,and MAP were recorded.he differences of arteriovenous O2 content (Ca-jvDO2) and glucose content (Da-jvglu) were calculated.Cognitive function was assessed by mini-mental state examination at 24 h before anesthesia and at 6,24,48 h and 72 h after anesthesia.Results Compared with T1,arterial partial pressure carbon dioxide(PaCO2) at T3-6,jugular venous partial pressure oxygen(PjvO2) at T3-5 and jugular venous oxygen saturation(SjvO2) at T4-5 were significantly increased in both groups,MAP at T2 were significantly decreased in both groups,MAP at T4-6 were significantly increased in group M,MAP at T3-6,SjvO2 [(75±9)%] at T6 and jugular venous lactate (Lacjv)[(2.0±0.5) mmol/L] at T5 were significantly increased and Ca-jvDO2[(5.2±1.5)%] at T5 were significantly decreased in group T(P<0.05).Compared with group T,CajvDO2[(5.9±1.6)%] at T5 was not significantly decreased,MAP at T4-6,SjvO2[(75±9)%] and Lacjv[(1.5±0.5) mmol/L] at T5 were not significantly increased,Da-jvglu before and after pneumoperitoneum

  12. EXPLORING THE MECHANISM OF ACUPUNCTURE IN THE TREATMENT OF STROKE FROM CHANGES OF GLUCOSE METABOLISM IN THE CEREBRAL MOTOR CENTER

    Institute of Scientific and Technical Information of China (English)

    石现; 左芳; 关玲

    2004-01-01

    Objective:To observe the effect of acupuncture on cerebral glucose metabolism in stroke patients.Methods:Changes of cerebral glucose metabolism before and after acupuncture stimulation were observed in six cases of stroke patients by using positron emission tomography (PET) scanner. Electroacupuncture (EA,4 Hz, continuous waves and duration of 20 min) was applied to Baihui (百会GV 20) and right Qubin (曲鬓GB 7). 18 Fluorine deoxyglucose (18FDG), a developer (radioactive form of glucose) for showing the levels of the brain functional activity was given to the patients intravenously. SPM software was used to deal with the data of each pixel point by unilateral t-test (Ts: P=0.05), then, the regions showing increase/decrease of the glucose metabolism were obtained.Results:After acupuncture stimulation, significant increase of glucose metabolism was found to be in the first somatic motor cortical region (MI), supplementary motor area (SMA), premotor area (PMC), and the superior parietal lobule (LPs) on the healthy side of the brain; while the decrease of glucose metabolism found in MI, PMC and LPs on the focus side. In addition to the cerebral regions related to the motor function, changes of glucose metabolism were also found in the parietal lobule and basal ganglion area, central parietal gyrus, superior parietal gyrus, putamen, cerebellum, etc..Conclusion:Acupuncture of Qubin (GB 7) and Baihui (GV 20) can activate motor-related cerebral structures in the bilateral cerebral hemisphere and induce excitement reaction of the potentially correlative motor area so as to compensate or assist the injured motor area to play a role in improving motor function in stroke patients.

  13. Pharmacologic modulation of cerebral metabolic derangement and excitotoxicity in a porcine model of traumatic brain injury and hemorrhagic shock

    DEFF Research Database (Denmark)

    Hwabejire, John O; Jin, Guang; Imam, Ayesha M;

    2013-01-01

    Cerebral metabolic derangement and excitotoxicity play critical roles in the evolution of traumatic brain injury (TBI). We have shown previously that treatment with large doses of valproic acid (VPA) decreases the size of brain lesion. The goal of this experiment was to determine whether this eff...

  14. Impact of Nutrition on Cerebral Circulation and Cognition in the Metabolic Syndrome

    Directory of Open Access Journals (Sweden)

    Laura Mellendijk

    2015-11-01

    Full Text Available The increasing prevalence of Metabolic Syndrome (MetS, defined as the clustering of abdominal obesity, dyslipidemia, hypertension, and hyperglycemia, appears to be driving the global epidemics cardiovascular disease (CVD and type 2 diabetes mellitus (T2DM. Nutrition has a major impact on MetS and plays an important role in the prevention, development, and treatment of its features. Structural and functional alterations in the vasculature, associated with MetS, might form the link between MetS and the increased risk of developing CVD and T2DM. Not only does the peripheral vasculature seem to be affected, but the syndrome has a profound impact on the cerebral circulation and thence brain structure as well. Furthermore, strong associations are shown with stroke, cognitive impairment, and dementia. In this review the impact of nutrition on the individual components of MetS, the effects of MetS on peripheral and cerebral vasculature, and its consequences for brain structure and function will be discussed.

  15. 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

    Spatially resolved spectroscopy (SRS) allows the estimation of absolute tissue oxygen saturation, the ratio of oxygenated to total hemoglobin concentration, which may facilitate the comparison of results among patients. Eighty-two premature infants were included over two years. The cerebral tissue...

  16. Relationship between salivary cortisol levels and regional cerebral glucose metabolism in nondemented elderly subjects

    Energy Technology Data Exchange (ETDEWEB)

    Kwak, Young Bin; Cho, Sang Soo; Lee, Sung Ha; Chey, Jean Yung; Kim, Sang Eun [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2004-07-01

    Cortisol is a primary stress hormone for flight-or-fight response in human. Increased levels of cortisol have been associated with memory and learning impairments. However, little is known about the role of cortisol on brain/cognitive functions in older adults. We compared regional cerebral glucose metabolism between elderly subjects with high and low cortisol levels using FDG PET. Salivary cortisol levels were measured four times during a day, and an average of the four measurements was used as the standard cortisol level for the analyses. From a population of 120 nondemented elderly subjects, 19 (mean age, 70.1{+-}4.9 y: 2 males and 17 females) were identified as the high (> mean + 1 SD of the total population) cortisol subjects (mean cortisol, 0.69{+-}0.09 {mu} g/dL), while 14 (mean age, 67.2{+-}4.5 y: all females) as the low (< mean 1 SD) cortisol (mean cortisol, 0.27{+-}0.03 {mu} g/dL). A voxel-wise comparison of FDG PET images from the high and low cortisol subjects was performed using SPM99. When compared with the low cortisol group, the high cortisol group had significant hypometabolism in the right middle temporal gyrus, left precuneus, right parahippocampal gyrus, right inferior temporal and superior temporal gyri (P < 0.01 uncorrected, k = 100). There was no significant increase of glucose metabolism in the high cortisol group compared with the low cortisol group (P < 0.01 uncorrected, k = 100). The high cortisol elderly subjects had hypometabolism in the parahippocampal and temporal gyri and precuneus, regions involved in memory and other cognitive functions. This may represent the preclinical metabolic correlates of forthcoming cognitive dysfunction associated with stress in the elderly. Longitudinal studies of brain metabolism and cognitive function are warranted.

  17. Reduced Cerebral Oxygen Content in the DG and SVZ In Situ Promotes Neurogenesis in the Adult Rat Brain In Vivo.

    Directory of Open Access Journals (Sweden)

    Kuan Zhang

    Full Text Available Neurogenesis in the adult brain occurs mainly within two neurogenic structures, the dentate gyrus (DG of the hippocampus and the sub-ventricular zone (SVZ of the forebrain. It has been reported that mild hypoxia promoted the proliferation of Neural Stem Cells (NSCsin vitro. Our previous study further demonstrated that an external hypoxic environment stimulated neurogenesis in the adult rat brain in vivo. However, it remains unknown how external hypoxic environments affect the oxygen content in the brain and result in neurogenesis. Here we use an optical fiber luminescent oxygen sensor to detect the oxygen content in the adult rat brain in situ under normoxia and hypoxia. We found that the distribution of oxygen in cerebral regions is spatiotemporally heterogeneous. The Po2 values in the ventricles (45∼50 Torr and DG (approximately 10 Torr were much higher than those of other parts of the brain, such as the cortex and thalamus (approximately 2 Torr. Interestingly, our in vivo studies showed that an external hypoxic environment could change the intrinsic oxygen content in brain tissues, notably reducing oxygen levels in both the DG and SVZ, the major sites of adult neurogenesis. Furthermore, the hypoxic environment also increased the expression of HIF-1α and VEGF, two factors that have been reported to regulate neurogenesis, within the DG and SVZ. Thus, we have demonstrated that reducing the oxygen content of the external environment decreased Po2 levels in the DG and SVZ. This reduced oxygen level in the DG and SVZ might be the main mechanism triggering neurogenesis in the adult brain. More importantly, we speculate that varying oxygen levels may be the physiological basis of the regionally restricted neurogenesis in the adult brain.

  18. Reduced Cerebral Oxygen Content in the DG and SVZ In Situ Promotes Neurogenesis in the Adult Rat Brain In Vivo.

    Science.gov (United States)

    Zhang, Kuan; Zhou, Yanzhao; Zhao, Tong; Wu, Liying; Huang, Xin; Wu, Kuiwu; Xu, Lun; Li, Dahu; Liu, Shuhong; Zhao, Yongqi; Fan, Ming; Zhu, Lingling

    2015-01-01

    Neurogenesis in the adult brain occurs mainly within two neurogenic structures, the dentate gyrus (DG) of the hippocampus and the sub-ventricular zone (SVZ) of the forebrain. It has been reported that mild hypoxia promoted the proliferation of Neural Stem Cells (NSCs)in vitro. Our previous study further demonstrated that an external hypoxic environment stimulated neurogenesis in the adult rat brain in vivo. However, it remains unknown how external hypoxic environments affect the oxygen content in the brain and result in neurogenesis. Here we use an optical fiber luminescent oxygen sensor to detect the oxygen content in the adult rat brain in situ under normoxia and hypoxia. We found that the distribution of oxygen in cerebral regions is spatiotemporally heterogeneous. The Po2 values in the ventricles (45∼50 Torr) and DG (approximately 10 Torr) were much higher than those of other parts of the brain, such as the cortex and thalamus (approximately 2 Torr). Interestingly, our in vivo studies showed that an external hypoxic environment could change the intrinsic oxygen content in brain tissues, notably reducing oxygen levels in both the DG and SVZ, the major sites of adult neurogenesis. Furthermore, the hypoxic environment also increased the expression of HIF-1α and VEGF, two factors that have been reported to regulate neurogenesis, within the DG and SVZ. Thus, we have demonstrated that reducing the oxygen content of the external environment decreased Po2 levels in the DG and SVZ. This reduced oxygen level in the DG and SVZ might be the main mechanism triggering neurogenesis in the adult brain. More importantly, we speculate that varying oxygen levels may be the physiological basis of the regionally restricted neurogenesis in the adult brain.

  19. 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.

  20. Interactions between mitochondrial reactive oxygen species and cellular glucose metabolism

    NARCIS (Netherlands)

    Liemburg-Apers, D.C.; Willems, P.H.G.M.; Koopman, W.J.H.; Grefte, Sander

    2015-01-01

    Mitochondrial reactive oxygen species (ROS) production and detoxification are tightly balanced. Shifting this balance enables ROS to activate intracellular signaling and/or induce cellular damage and cell death. Increased mitochondrial ROS production is observed in a number of pathological condit

  1. Altered free radical metabolism in acute mountain sickness: implications for dynamic cerebral autoregulation and blood-brain barrier function

    DEFF Research Database (Denmark)

    Bailey, D M; Evans, K A; James, P E

    2008-01-01

    (2)) and following 6 h passive exposure to hypoxia (12% O(2)). Blood flow velocity in the middle cerebral artery (MCAv) and mean arterial blood pressure (MAP) were measured for determination of CA following calculation of transfer function analysis and rate of regulation (RoR). Nine subjects......We tested the hypothesis that dynamic cerebral autoregulation (CA) and blood-brain barrier (BBB) function would be compromised in acute mountain sickness (AMS) subsequent to a hypoxia-mediated alteration in systemic free radical metabolism. Eighteen male lowlanders were examined in normoxia (21% O...

  2. 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.

  3. Tyrosine impairs enzymes of energy metabolism in cerebral cortex of rats.

    Science.gov (United States)

    de Andrade, Rodrigo Binkowski; Gemelli, Tanise; Rojas, Denise Bertin; Funchal, Cláudia; Dutra-Filho, Carlos Severo; Wannmacher, Clovis Milton Duval

    2012-05-01

    Tyrosine levels are abnormally elevated in tissues and physiological fluids of patients with inborn errors of tyrosine catabolism, especially in tyrosinemia type II, which is caused by deficiency of tyrosine aminotransferase and provokes eyes, skin, and central nervous system disturbances. Considering that the mechanisms of brain damage in these disorders are poorly known, in this study, we investigated the in vivo and in vitro effects of tyrosine on some parameters of energy metabolism in cerebral cortex of 14-day-old Wistar rats. We observed that 2 mM tyrosine inhibited in vitro the pyruvate kinase (PK) activity and that this inhibition was prevented by 1 mM reduced glutathione with 30, 60, and 90 min of preincubation. Moreover, administration of tyrosine methyl ester (TME) (0.5 mg/g of body weight) decreased the activity of PK and this reduction was prevented by pre-treatment with creatine (Cr). On the other hand, tyrosine did not alter adenylate kinase (AK) activity in vitro, but administration of TME enhanced AK activity not prevented by Cr pre-treatment. Finally, TME administration decreased the activity of CK from cytosolic and mitochondrial fractions and this diminution was prevented by Cr pre-treatment. The results suggest that tyrosine alters essential sulfhydryl groups necessary for CK and PK functions, possibly through oxidative stress. In case this also occurs in the patients, it is possible that energy metabolism alterations may contribute, along with other mechanisms, to the neurological dysfunction of hypertyrosinemias.

  4. Gender differences in age-related decline in regional cerebral glucose metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Bang, Seong Ae; Cho, Sang Soo; Yoon, Eun Jin; Park, Hyun Soo; Lee, Eun Ju; Kim, Yu Kyeong; Kim, Sang Sun [Seoul National Univ. College of Medicine, Seoul (Korea, Republic of)

    2007-07-01

    In this study, we investigated gender differences in age-related declines in regional cerebral glucose metabolism using FDG-PET in a large population sample with a broad age range. 230 healthy subjects (90 male; age: 34-80 y, 140 females; age: 33-82 y) participated. Correlation maps showing age related declines in glucose uptake were created separately for each gender in SPM2. Using population-based probabilistic volume of interests (VOIs), VOIs were defined for the regions showing significant decline with aging. Age related declines were separately assessed within each age range using analysis of covariate in SPSS 13.0. In the total population without gender effect, age-related negative correlation of glucose metabolism was found in the bilateral inferior frontal gyri, bilateral caudate, bilateral thalamus, left insula, left superior frontal gyrus, left uncus, right superior temporal gyrus, right medial frontal gyrus, right parahippocampal gyrus, right anterior cingulate gyrus (P < 0.001 corrected, extent threshold k = 100). 14 VOIs values of brain regions were calculated based on this negative correlation results. The rate of decline across all defined VOIs assessed in the age category of 'more than 70' referenced to the category of '30- 39years' were 7.85% in the entire sample; 7.62% in male and 8.09% in female. Detailed analyses of declines in each age range showed separable patterns of declines across gender. In males, greater decline was observed after the age 60 (20.45%) than the ages of 30 and 50(7.98%). Whereas in females, greater declines were found in age 60s (20.15%) compared to 50s, and in 40(14.84%) compared to 30s. Age-related decline in cerebral glucose metabolism was found in both genders. We further observed that males show a relatively constant pattern of decline across a life span; whereas, females show a pattern of steep changes aging to 60s and to 40s, which may be related to changes in sex hormone levels after menopause.

  5. Magnetic resonance imaging of tumor oxygenation and metabolic profile

    DEFF Research Database (Denmark)

    Krishna, Murali C.; Matsumoto, Shingo; Saito, Keita;

    2013-01-01

    which can characterize such features non-invasively and repeatedly will be of significant value in planning treatment as well as monitoring response to treatment. The three techniques based on magnetic resonance imaging (MRI) are reviewed here. Tumor pO2 can be measured by two MRI methods requiring......The tumor microenvironment is distinct from normal tissue as a result of abnormal vascular network characterized by hypoxia, low pH, high interstitial fluid pressure and elevated glycolytic activity. This poses a barrier to treatments including radiation therapy and chemotherapy. Imaging methods...... an exogenous contrast agent: electron paramagnetic resonance imaging (EPRI) and Overhauser magnetic resonance imaging (OMRI). Tumor metabolic profile can be assessed by a third method, hyperpolarized metabolic MR, based on injection of hyperpolarized biological molecules labeled with 13C or 15N and MR...

  6. Low oxygen levels as a trigger for enhancement of respiratory metabolism in Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Wiebe Marilyn G

    2009-10-01

    Full Text Available Abstract Background The industrially important yeast Saccharomyces cerevisiae is able to grow both in the presence and absence of oxygen. However, the regulation of its metabolism in conditions of intermediate oxygen availability is not well characterised. We assessed the effect of oxygen provision on the transcriptome and proteome of S. cerevisiae in glucose-limited chemostat cultivations in anaerobic and aerobic conditions, and with three intermediate (0.5, 1.0 and 2.8% oxygen levels of oxygen in the feed gas. Results The main differences in the transcriptome were observed in the comparison of fully aerobic, intermediate oxygen and anaerobic conditions, while the transcriptome was generally unchanged in conditions receiving different intermediate levels (0.5, 1.0 or 2.8% O2 of oxygen in the feed gas. Comparison of the transcriptome and proteome data suggested post-transcriptional regulation was important, especially in 0.5% oxygen. In the conditions of intermediate oxygen, the genes encoding enzymes of the respiratory pathway were more highly expressed than in either aerobic or anaerobic conditions. A similar trend was also seen in the proteome and in enzyme activities of the TCA cycle. Further, genes encoding proteins of the mitochondrial translation machinery were present at higher levels in all oxygen-limited and anaerobic conditions, compared to fully aerobic conditions. Conclusion Global upregulation of genes encoding components of the respiratory pathway under conditions of intermediate oxygen suggested a regulatory mechanism to control these genes as a response to the need of more efficient energy production. Further, cells grown in three different intermediate oxygen levels were highly similar at the level of transcription, while they differed at the proteome level, suggesting post-transcriptional mechanisms leading to distinct physiological modes of respiro-fermentative metabolism.

  7. Comparison of Cerebral Glucose Metabolism between Possible and Probable Multiple System Atrophy

    Directory of Open Access Journals (Sweden)

    Kyum-Yil Kwon

    2009-05-01

    Full Text Available Background: To investigate the relationship between presenting clinical manifestations and imaging features of multisystem neuronal dysfunction in MSA patients, using 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET. Methods: We studied 50 consecutive MSA patients with characteristic brain MRI findings of MSA, including 34 patients with early MSA-parkinsonian (MSA-P and 16 with early MSA-cerebellar (MSA-C. The cerebral glucose metabolism of all MSA patients was evaluated in comparison with 25 age-matched controls. 18F-FDG PET results were assessed by the Statistic Parametric Mapping (SPM analysis and the regions of interest (ROI method. Results: The mean time from disease onset to 18F-FDG PET was 25.9±13.0 months in 34 MSA-P patients and 20.1±11.1 months in 16 MSA-C patients. Glucose metabolism of the putamen showed a greater decrease in possible MSA-P than in probable MSA-P (p=0.031. Although the Unified Multiple System Atrophy Rating Scale (UMSARS score did not differ between possible MSA-P and probable MSA-P, the subscores of rigidity (p=0.04 and bradykinesia (p= 0.008 were significantly higher in possible MSA-P than in probable MSA-P. Possible MSA-C showed a greater decrease in glucose metabolism of the cerebellum than probable MSA-C (p=0.016. Conclusions: Our results may suggest that the early neuropathological pattern of possible MSA with a predilection for the striatonigral or olivopontocerebellar system differs from that of probable MSA, which has prominent involvement of the autonomic nervous system in addition to the striatonigral or olivopontocerebellar system.

  8. Mitochondrial metabolism, reactive oxygen species, and macrophage function-fishing for insights.

    Science.gov (United States)

    Hall, Christopher J; Sanderson, Leslie E; Crosier, Kathryn E; Crosier, Philip S

    2014-11-01

    Metabolism and defense mechanisms that protect against pathogens are two fundamental requirements for the survival of multicellular organisms. Research into metabolic disease has revealed these core mechanisms are highly co-dependent. This emerging field of research, termed immunometabolism, focuses on understanding how metabolism influences immunological processes and vice versa. It is now accepted that obesity influences the immune system and that obesity-driven inflammation contributes to many diseases including type 2 diabetes, cardiovascular disease and Alzheimer's disease. The immune response requires the reallocation of nutrients within immune cells to different metabolic pathways to satisfy energy demands and the production of necessary macromolecules. One aspect of immunometabolic research is understanding how these metabolic changes help regulate specific immune cell functions. It is hoped that further understanding of the pathways involved in managing this immunological-metabolic interface will reveal new ways to treat metabolic disease. Given their growing status as principle drivers of obesity-associated inflammation, monocytes/macrophages have received much attention when studying the consequences of inflammation within adipose tissue. Less is known regarding how metabolic changes within macrophages (metabolic reprogramming) influence their immune cell function. In this review, we focus on our current understanding of how monocytes/macrophages alter their intracellular metabolism during the immune response and how these changes dictate specific effector functions. In particular, the immunomodulatory functions of mitochondrial metabolism and mitochondrial reactive oxygen species. We also highlight how the attributes of the zebrafish model system can be exploited to reveal new mechanistic insights into immunometabolic processes.

  9. Positron computed tomography studies of cerebral glucose metabolism in man: theory and application in nuclear medicine.

    Science.gov (United States)

    Phelps, M E

    1981-01-01

    The capability of positron computed tomography (PCT) to delineate the substructures of the brain and its facility for accurately measuring the local tissue radioactivity concentration allow the application of tracer kinetic models for the study of local cerebral function in man. This principle and an adaptation of the 14C-deoxyglucose (DG) model of Sokoloff et al. with 18F-2-fluoro-deoxy-D-glucose (FDG) is being used at UCLA. Brookhaven National Laboratory, University of Pennsylvania, NIH, and the Massachusetts General Hospital to determine the local cerebral glucose metabolic rate (LCMRGIc) in normal man at rest and during sensory activation and the changes that occur in patients with a variety of cerebral disorders. Kinetic studies with PCT have been employed to measure the rate constants of the model in different gray and white matter structures of the brain in both normal and ischemic states. The precision of the method in normals has been shown to be about +/- 5% for 1.5-2.0 sq cm regions of the brain. Studies in normals have yielded values for hemispheric CMRGIc that are in agreement with measurement using the Kety-Schmidt technique and LCMRGIc values in agreement with values in monkeys using DG autoradiography. Studies in volunteers subjected to visual and auditory stimulation are demonstrating the potential of this technique for investigating the human brain's response to different stimuli. STudies in patients with stroke show excellent correlation between the degree, extent, and particular structures involved and the clinical symptoms. The method consistently detected hypometabolism in cortical, thalamic, and striatal tissues that were dysfunctional due to deactivation or damage but which appeared normal on x-ray CT. Studies in patients with partial epilepsy have shown hypometabolic zones that highly correlated anatomically with interictal EEG spike foci and were associated with normal x-ray CT studies in 77% of the patients studied. The studies on

  10. Cold tolerance is unaffected by oxygen availability despite changes in anaerobic metabolism

    Science.gov (United States)

    Boardman, Leigh; Sørensen, Jesper G.; Koštál, Vladimír; Šimek, Petr; Terblanche, John S.

    2016-01-01

    Insect cold tolerance depends on their ability to withstand or repair perturbations in cellular homeostasis caused by low temperature stress. Decreased oxygen availability (hypoxia) can interact with low temperature tolerance, often improving insect survival. One mechanism proposed for such responses is that whole-animal cold tolerance is set by a transition to anaerobic metabolism. Here, we provide a test of this hypothesis in an insect model system (Thaumatotibia leucotreta) by experimental manipulation of oxygen availability while measuring metabolic rate, critical thermal minimum (CTmin), supercooling point and changes in 43 metabolites in moth larvae at three key timepoints (before, during and after chill coma). Furthermore, we determined the critical oxygen partial pressure below which metabolic rate was suppressed (c. 4.5 kPa). Results showed that altering oxygen availability did not affect (non-lethal) CTmin nor (lethal) supercooling point. Metabolomic profiling revealed the upregulation of anaerobic metabolites and alterations in concentrations of citric acid cycle intermediates during and after chill coma exposure. Hypoxia exacerbated the anaerobic metabolite responses induced by low temperatures. These results suggest that cold tolerance of T. leucotreta larvae is not set by oxygen limitation, and that anaerobic metabolism in these larvae may contribute to their ability to survive in necrotic fruit. PMID:27619175

  11. Cold tolerance is unaffected by oxygen availability despite changes in anaerobic metabolism

    Science.gov (United States)

    Boardman, Leigh; Sørensen, Jesper G.; Koštál, Vladimír; Šimek, Petr; Terblanche, John S.

    2016-09-01

    Insect cold tolerance depends on their ability to withstand or repair perturbations in cellular homeostasis caused by low temperature stress. Decreased oxygen availability (hypoxia) can interact with low temperature tolerance, often improving insect survival. One mechanism proposed for such responses is that whole-animal cold tolerance is set by a transition to anaerobic metabolism. Here, we provide a test of this hypothesis in an insect model system (Thaumatotibia leucotreta) by experimental manipulation of oxygen availability while measuring metabolic rate, critical thermal minimum (CTmin), supercooling point and changes in 43 metabolites in moth larvae at three key timepoints (before, during and after chill coma). Furthermore, we determined the critical oxygen partial pressure below which metabolic rate was suppressed (c. 4.5 kPa). Results showed that altering oxygen availability did not affect (non-lethal) CTmin nor (lethal) supercooling point. Metabolomic profiling revealed the upregulation of anaerobic metabolites and alterations in concentrations of citric acid cycle intermediates during and after chill coma exposure. Hypoxia exacerbated the anaerobic metabolite responses induced by low temperatures. These results suggest that cold tolerance of T. leucotreta larvae is not set by oxygen limitation, and that anaerobic metabolism in these larvae may contribute to their ability to survive in necrotic fruit.

  12. 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

  13. Oxygen supply to the fetal cerebral circulation in hypoplastic left heart syndrome: a simulation study based on the theoretical models of fetal circulation.

    Science.gov (United States)

    Sakazaki, Sayaka; Masutani, Satoshi; Sugimoto, Masaya; Tamura, Masanori; Kuwata, Seiko; Kurishima, Clara; Saiki, Hirofumi; Iwamoto, Yoichi; Ishido, Hirotaka; Senzaki, Hideaki

    2015-03-01

    Hypoxia due to congenital heart diseases (CHDs) adversely affects brain development during the fetal period. Head circumference at birth is closely associated with neuropsychiatric development, and it is considerably smaller in newborns with hypoplastic left heart syndrome (HLHS) than in normal newborns. We performed simulation studies on newborns with CHD to evaluate the cerebral circulation during the fetal period. The oxygen saturation of cerebral blood flow in newborns with CHD was simulated according to a model for normal fetal circulation in late pregnancy. We compared the oxygen saturation of cerebral blood flow between newborns with tricuspid atresia (TA; a disease showing univentricular circulation and hypoplasia of the right ventricle), those with transposition of the great arteries (TGA; a disease showing abnormal mixing of arterial and venous blood), and those with HLHS. The oxygen saturation of cerebral blood flow in newborns with normal circulation was 75.7 %, whereas it was low (49.5 %) in both newborns with HLHS and those with TA. Although the oxygen level is affected by the blood flow through the foramen ovale, the oxygen saturation in newborns with TGA was even lower (43.2 %). These data, together with previous reports, suggest that the cerebral blood flow rate is decreased in newborns with HLHS, and the main cause was strongly suspected to be retrograde cerebral perfusion through a patent ductus arteriosus. This study provides important information about the neurodevelopmental prognosis of newborns with HLHS and suggests the need to identify strategies to resolve this unfavorable cerebral circulatory state in utero.

  14. 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.

  15. Effect of hypertensive reperfusion on the changes between cerebral oxygen delivery and uptake after cardiac arrest and resuscitation in dogs

    Institute of Scientific and Technical Information of China (English)

    杜权; 马永达; 葛衡江; 刘怀琼; 李阳

    2004-01-01

    Objective: To study the changes between cerebral oxygen (O2) delivery and uptake in dogs resuscitated under normotension or hypertension for 4 h. Methods: The model of ventricular fibrillation of 8 min in 12 dogs was made,followed by open cardiopulmonary resuscitation, reperfnsion with normal or high mean arterial pressure (MAP), and controlled ventilation to 4 h. Animals were randomly assigned into Group NT (normotensive reperfusion, n = 6) and Group HT(hypertensive reperfusion, n = 6). Cerebral arteriovenous (sagittal sinus) O2 content difference (Ca-ssO2) and venous(sagittal sinus) PO2(PssO2) were determined before cardiac arrest (CA) and 30, 60, 120, and 240 min after CA. Results: In Group NT, Ca-ssO2 was lower at 30 min ( P < 0.05) but higher at 240 min ( P < 0.01 ) after CA than that before CA. In Group HT, Ca-ssO2 was not significantly different from that in Group NT before CA but was lower than that in Group NT at 30 min after CA ( P < 0.01 ). Ca-ssO2 was not significantly different in Group NT and HT thereafter. In both groups,PssO2 was both higher at 30 min after reperfnsion ( P < 0.01 ) and at 240 min after reperfnsion lower ( P < 0.05) than those before CA .At 30 min after reperfusion, PssO2 was higher (P<0.01) in Group HT than that in Group NT, with insignificant difference between two groups. Conclusion: Cerebral O2 delivery and uptake are mismatched after CA and resuscitation. Hypertensive reperfusion improves oxygen delivery to the brain early after CA.

  16. Hyperbaric oxygen in the treatment of hypertension- induced cerebral hemorrhage on 34 cases%高血压脑出血术后高压氧治疗34例

    Institute of Scientific and Technical Information of China (English)

    程晋成; 沈月萍; 王水平; 吴杨

    2003-01-01

    @@ INTRODUCTION In this study,we investigated effect of hyperbaric oxygen(HBO) on the hypertension- induced basio- cerebral hemorrhage.The affected patients often showed signs of cerebral circulation disorder,spasm of vessels,insufficiency of cerebral blood supply and intracranial hypertension.

  17. The role of the mitochondrial calcium uniporter in cerebral ischemia/reperfusion injury in rats involves regulation of mitochondrial energy metabolism.

    Science.gov (United States)

    Zhao, Qin; Wang, Shilei; Li, Yu; Wang, Peng; Li, Shuhong; Guo, Yunliang; Yao, Ruyong

    2013-04-01

    The mitochondrial calcium uniporter (MCU) maintains intracellular Ca2+ homeostasis by transporting Ca2+ from the cell cytosol into the mitochondrial matrix and is important for shaping Ca2+ signals and the activation of programmed cell death. Inhibition of MCU by ruthenium red (RR) or Ru360 has previously been reported to protect against neuronal death. The aim of the present study was to analyze the mechanisms underlying the effects of MCU activity in a rat model of cerebral ischemia/reperfusion (I/R) injury. Adult male Wistar rats were divided into 4 groups; sham, I/R, I/R + RR and I/R + spermine (Sper) and were subjected to reversible middle cerebral artery occlusion for 2 h followed by 24 h of reperfusion. A bolus injection of RR administered 30 min prior to ischemia was found to significantly decrease the total infarct volume and reduce neuronal damage and cell apoptosis compared with ischemia/reperfusion values. However, treatment with Sper, an activator of the MCU, increased the injury induced by I/R. Analysis of energy metabolism revealed that I/R induced progressive inhibition of complexes I‑IV of the electron transport chain, decreased ATP production, dissipated the mitochondrial membrane potential and increased the generation of reactive oxygen species. Treatment with RR ameliorated the condition, while spermine had the opposite effect. In conclusion, blocking MCU was demonstrated to exert protective effects against I/R injury and this process may be mediated by the prevention of energy failure.

  18. 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.

  19. 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

    Science.gov (United States)

    Venâncio, Carlos; Souza, Almir P.; Ferreira, Luísa Maria; Branco, Paula Sério; de Pinho, Paula Guedes; Amorim, Pedro; Ferreira, David A.

    2014-01-01

    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. PMID:24971192

  20. Decreased cerebral metabolism in stroke-prone spontaneously hypertensive rats (SHRSP) with stroke and its possible improvement by Solcoseryl.

    Science.gov (United States)

    Yamasaki, Y; Yamamoto, Y; Senga, Y; Isogai, M; Shimizu, H; Yamori, Y

    1991-01-01

    Local cerebral glucose utilization (LCGU) was decreased in SHRSP with stroke compared with normotensive Wistar rats. The decrement of LCGU was less in Solcoseryl-treated SHRSP with stroke than that in saline-treated SHRSP with stroke and these brain areas where LCGU was less damaged, in Solcoseryl-treated SHRSP were consistent with the important functioning sites of emotion, motor movement and memory. The result suggests that Solcoseryl may be useful for metabolic improvement of the brain damage after stroke.

  1. Integration of Carbon, Nitrogen, and Oxygen Metabolism in Escherichia coli

    Science.gov (United States)

    2012-10-22

    glycolysis and the  citric   acid   cycle  and monitored the effect on RpoS degradation  in vivo. Nutrient  upshifts trigger RpoS degradation  independently...Yuan  et  al.,  2009). We  successfully combined the simplified nitrogen assimilation model with simplified models of glycolysis and the  TCA  cycle  to...TCA  cycle  (where carbon and nitrogen metabolism directly intersect). Our  investigation  yielded  significant  advances  in  the  understanding  of  E

  2. Cerebral circulation and metabolism in the patients with higher brain dysfunction caused by chronic minor traumatic brain injury. A study by the positron emission tomography in twenty subjects with normal MRI findings

    Energy Technology Data Exchange (ETDEWEB)

    Kabasawa, Hidehiro; Ogawa, Tetsuo; Iida, Akihiko; Matsubara, Michitaka [Nagoya City Rehabilitation and Sports Center (Japan)

    2002-06-01

    Many individuals are affected on their higher brain functions, such as intelligence, memory, and attention, even after minor traumatic brain injury (MTBI). Although higher brain dysfunction is based on impairment of the cerebral circulation and metabolism, the precise relationship between them remains unknown. This study was undertaken to investigate the relationship between the cerebral circulation or cerebral metabolism and higher brain dysfunction. Twenty subjects with higher brain dysfunction caused by chronic MTBI were studied. They had no abnormal MRI findings. The full-scale intelligence quotient (FIQ) were quantitatively evaluated by the Wechsler Adult Intelligence Scale-Revised (WAIS-R), and the subjects were classified into the normal group and the impaired group. Concurrent with the evaluation of FIQ, positron emission tomography (PET) was performed by the steady state method with {sup 15}O gases inhalation. Regional cerebral blood flow (rCBF), oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO{sub 2}) were calculated in the bilateral frontal, parietal, temporal, and occipital lobe. First, of all twenty subjects, we investigated rCBF, OEF and CMRO{sub 2} in all regions. Then we compared rCBF, OEF, and CMRO{sub 2} between the normal group and the impaired group based on FIQ score. We also studied the change of FIQ score of 13 subjects 9.3 months after the first evaluation. In addition, we investigated the change of rCBF, OEF and CMRO{sub 2} along with the improvement of FIQ score. Although rCBF and OEF of all subjects were within the normal range in all regions, CMRO{sub 2} of more than half of subjects was under the lower normal limit in all regions except in the right occipital lobe, showing the presence of ''relative luxury perfusion''. Comparison of rCBF, OEF and CMRO{sub 2} between normal group and impaired group revealed that CMRO{sub 2} of the impaired group was significantly lower than that of the

  3. Cerebral glucose metabolism in neurofibromatosis type 1 assessed with [18F]-2-fluoro-2-deoxy-D-glucose and PET.

    Science.gov (United States)

    Balestri, P; Lucignani, G; Fois, A; Magliani, L; Calistri, L; Grana, C; Di Bartolo, R M; Perani, D; Fazio, F

    1994-01-01

    Cerebral PET with [18F]-2-fluoro-2-deoxy-D-glucose has been performed in four patients with neurofibromatosis type 1 (NF1) to assess the relation between cerebral metabolic activity, MRI, and the presence of neurological symptoms, including seizures, as well as mental and language retardation. Widespread hypometabolism occurred in three of the patients. The lesions on MRI, which were localised in the subcortical white matter and grey structures, had normal rates of glucose metabolism. This finding suggests that the abnormalities seen on MRI are not due to defective blood supply, localised oedema, or grey matter heterotopic foci as previously hypothesised. The presence of the hypometabolic areas seems to be inconsistently related to the occurrence of seizures and is not proportional to the degree of mental impairment. This study provides evidence of a widespread cerebral hypometabolism that is not related to the presence of MRI abnormalities; conversely normal metabolism was present in the areas with an abnormal MRI signal. Images PMID:7798976

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

    DEFF Research Database (Denmark)

    Hirasawa, Ai; Kaneko, Takahito; Tanaka, Naoki;

    2016-01-01

    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 cerebral...

  5. Visual and SPM analysis of regional cerebral glucose metabolism in adult patients with neurofibromatosis

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Joon Kee; An, Young Sil; Hong, Seon Pyo; Joh, Chul Woo; Yoon, Seok Nam [Ajou University, School of Medicine, Suwon (Korea, Republic of)

    2005-07-01

    We evaluated the regional cerebral glucose metabolism in adult patients with neurofibromatosis (NF) using visual and SPM analysis, and compared with MRI findings. A total of 11 adult patients with NF type I were prospectively included in the study. All patients underwent F-18 FDG PET and brain MRI within 2 month of each other. All hypometabolic areas on PET were determined visually by 2 nuclear medicine physician and compared with MRI findings. SPM analysis was done using 42 normal controls with p = 0.005. Seven of 11 PET images showed 10 hypometabolic areas and 4 of 11 MRIs showed 6 areas of signal change brain parenchyma. Hypometabolic areas were bilateral thalamus (n=5), left temporal cortex (n=4) and dentate nucleus (n=1). In only 2 lesions (thalamus and dentate nucleus), hypometabolic foci were consistently related to signal change on MRI. SPM analysis revealed significantly decreased area in bilateral thalamus and left temporal cortex. F-18 FDG PET revealed significant hypometabolism in bilateral thalamus and left temporal cortex in adult patients with NF, and it might be helpful in understanding developmental abnormality of NF.

  6. High intensity aerobic interval training improves peak oxygen consumption in patients with metabolic syndrome: CAT

    Directory of Open Access Journals (Sweden)

    Alexis Espinoza Salinas

    2014-06-01

    Full Text Available Introduction A number of cardiovascular risk factors characterizes the metabolic syndrome: insulin resistance (IR, low HDL cholesterol and high triglycerides. The aforementioned risk factors lead to elevated levels of abdominal adipose tissue, resulting in oxygen consumption deficiency. Purpose To verify the validity and applicability of using high intensity interval training (HIIT in subjects with metabolic syndrome and to answer the following question: Can HIIT improve peak oxygen consumption? Method The systematic review "Effects of aerobic interval training on exercise capacity and metabolic risk factors in individuals with cardiometabolic disorders" was analyzed. Results Data suggests high intensity aerobic interval training increases peak oxygen consumption by a standardized mean difference of 3.60 mL/kg-1/min-1 (95% confidence interval, 0.28-4.91. Conclusion In spite of the methodological shortcomings of the primary studies included in the systematic review, we reasonably conclude that implementation of high intensity aerobic interval training in subjects with metabolic syndrome, leads to increases in peak oxygen consumption.

  7. Change of oxygen free radical metabolism and free amino acids of patients with hyperthyroidism

    Institute of Scientific and Technical Information of China (English)

    Hua-Ling Ruan; Li Zhao; Kun-Quan Guo; Kun Yang; Lin-Xiu Ye; Xue Sun

    2016-01-01

    Objective:To study the change situation of oxygen free radical metabolism and free amino acids of patients with hyperthyroidism.Methods:Eighty-one patients with hyperthyroidism who were treated in our hospital from May 2013 to October 2014 were selected as the observation group, while 81 healthy persons with health examination at the same period were the control group. Then, the serum oxygen free radical indexes and free amino acids of the two groups were respectively detected and compared, and the detection results of patients in the observation group with different etiologic types and basal metabolic rate were also compared. Results:The serum oxygen free radical related indexes of the observation group were all higher than those of the control group; the serum antioxidant related indexes were all lower than those of the control group; and the serum free amino acids levels were all obviously lower than those of the control group. Besides, the detection results of patients with severe hyperthyroidism in the observation group were worse than those of patients with mild and moderate disease, while the detection results of the observation group with different types of hyperthyroidism had no significant differences.Conclusions:The fluctuation of oxygen free radical metabolism and free amino acids of patients with hyperthyroidism are obvious, and the detection results of patients with different basal metabolic rates are also quite obvious.

  8. Blood oxygenation level-dependent (BOLD)-based techniques for the quantification of brain hemodynamic and metabolic properties - theoretical models and experimental approaches.

    Science.gov (United States)

    Yablonskiy, Dmitriy A; Sukstanskii, Alexander L; He, Xiang

    2013-08-01

    The quantitative evaluation of brain hemodynamics and metabolism, particularly the relationship between brain function and oxygen utilization, is important for the understanding of normal human brain operation, as well as the pathophysiology of neurological disorders. It can also be of great importance for the evaluation of hypoxia within tumors of the brain and other organs. A fundamental discovery by Ogawa and coworkers of the blood oxygenation level-dependent (BOLD) contrast opened up the possibility to use this effect to study brain hemodynamic and metabolic properties by means of MRI measurements. Such measurements require the development of theoretical models connecting the MRI signal to brain structure and function, and the design of experimental techniques allowing MR measurements to be made of the salient features of theoretical models. In this review, we discuss several such theoretical models and experimental methods for the quantification of brain hemodynamic and metabolic properties. The review's main focus is on methods for the evaluation of the oxygen extraction fraction (OEF) based on the measurement of the blood oxygenation level. A combination of the measurement of OEF and the cerebral blood flow (CBF) allows an evaluation to be made of the cerebral metabolic rate of oxygen consumption (CMRO2 ). We first consider in detail the magnetic properties of blood - magnetic susceptibility, MR relaxation and theoretical models of the intravascular contribution to the MR signal under different experimental conditions. We then describe a 'through-space' effect - the influence of inhomogeneous magnetic fields, created in the extravascular space by intravascular deoxygenated blood, on the formation of the MR signal. Further, we describe several experimental techniques taking advantage of these theoretical models. Some of these techniques - MR susceptometry and T2 -based quantification of OEF - utilize the intravascular MR signal. Another technique

  9. Spatial control of the energy metabolism of yeast cells through electrolytic generation of oxygen.

    Science.gov (United States)

    Warnke, Christian; Mair, Thomas; Witte, Hartmut; Reiher, Antje; Hauser, Marcus J B; Krost, Alois

    2009-11-03

    The metabolic dynamics of yeast cells is controlled by electric pulses delivered through a spatially extended yeast cell/Au electrode interface. Concomitant with voltage pulses, oxygen is generated electrolytically at the electrode surface and delivered to the cells. The generation of oxygen was investigated in dependence of the applied voltage, width of the voltage pulses and temperature of the electrolytic solution. The local oxygen pulses at the electrodes lead to a transient activation of the aerobic energy metabolism of the yeast cells causing a perturbation in their energy balance. The effect of these local perturbations on the temporal dynamics of glycolysis in yeast cells is quantified in dependence of the energy state of cells.

  10. Dual role of cerebral blood flow in regional brain temperature control in the healthy newborn infant.

    Science.gov (United States)

    Iwata, Sachiko; Tachtsidis, Ilias; Takashima, Sachio; Matsuishi, Toyojiro; Robertson, Nicola J; Iwata, Osuke

    2014-10-01

    Small shifts in brain temperature after hypoxia-ischaemia affect cell viability. The main determinants of brain temperature are cerebral metabolism, which contributes to local heat production, and brain perfusion, which removes heat. However, few studies have addressed the effect of cerebral metabolism and perfusion on regional brain temperature in human neonates because of the lack of non-invasive cot-side monitors. This study aimed (i) to determine non-invasive monitoring tools of cerebral metabolism and perfusion by combining near-infrared spectroscopy and echocardiography, and (ii) to investigate the dependence of brain temperature on cerebral metabolism and perfusion in unsedated newborn infants. Thirty-two healthy newborn infants were recruited. They were studied with cerebral near-infrared spectroscopy, echocardiography, and a zero-heat flux tissue thermometer. A surrogate of cerebral blood flow (CBF) was measured using superior vena cava flow adjusted for cerebral volume (rSVC flow). The tissue oxygenation index, fractional oxygen extraction (FOE), and the cerebral metabolic rate of oxygen relative to rSVC flow (CMRO₂ index) were also estimated. A greater rSVC flow was positively associated with higher brain temperatures, particularly for superficial structures. The CMRO₂ index and rSVC flow were positively coupled. However, brain temperature was independent of FOE and the CMRO₂ index. A cooler ambient temperature was associated with a greater temperature gradient between the scalp surface and the body core. Cerebral oxygen metabolism and perfusion were monitored in newborn infants without using tracers. In these healthy newborn infants, cerebral perfusion and ambient temperature were significant independent variables of brain temperature. CBF has primarily been associated with heat removal from the brain. However, our results suggest that CBF is likely to deliver heat specifically to the superficial brain. Further studies are required to assess the

  11. Metabolic cold adaptation of polar fish based on measurements of aerobic oxygen consumption: fact or artefact? Artefact!

    DEFF Research Database (Denmark)

    Steffensen, John Fleng

    2002-01-01

    a considerably elevated resting oxygen consumption, or standard metabolic rate, compared with oxygen consumption values of tropical or temperate fish extrapolated to similar low polar temperatures. Recent experiments on arctic and Antarctic fish, however, do not show elevated resting aerobic oxygen consumption......Whether metabolic cold adaptation in polar fish, based on measurements of aerobic standard metabolic rate, is a fact or an artefact has been a dispute since Holeton asked the question in 1974. So far polar fish had been considered to be metabolically cold adapted because they were reported to have...

  12. 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

    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...

  13. Dehydration accelerates reductions in cerebral blood flow during prolonged exercise in the heat without compromising brain metabolism.

    Science.gov (United States)

    Trangmar, Steven J; Chiesa, Scott T; Llodio, Iñaki; Garcia, Benjamin; Kalsi, Kameljit K; Secher, Niels H; González-Alonso, José

    2015-11-01

    Dehydration hastens the decline in cerebral blood flow (CBF) during incremental exercise, whereas the cerebral metabolic rate for O2 (CMRO2 ) is preserved. It remains unknown whether CMRO2 is also maintained during prolonged exercise in the heat and whether an eventual decline in CBF is coupled to fatigue. Two studies were undertaken. In study 1, 10 male cyclists cycled in the heat for ∼2 h with (control) and without fluid replacement (dehydration) while internal and external carotid artery blood flow and core and blood temperature were obtained. Arterial and internal jugular venous blood samples were assessed with dehydration to evaluate CMRO2 . In study 2, in 8 male subjects, middle cerebral artery blood velocity was measured during prolonged exercise to exhaustion in both dehydrated and euhydrated states. After a rise at the onset of exercise, internal carotid artery flow declined to baseline with progressive dehydration (P exercise. During exhaustive exercise, however, euhydration delayed but did not prevent the decline in cerebral perfusion. In conclusion, during prolonged exercise in the heat, dehydration accelerates the decline in CBF without affecting CMRO2 and also restricts extracranial perfusion. Thus, fatigue is related to a reduction in CBF and extracranial perfusion rather than CMRO2 .

  14. Determination of relative CMRO2 from CBF and BOLD changes: significant increase of oxygen consumption rate during visual stimulation

    DEFF Research Database (Denmark)

    Kim, S.G.; Rostrup, Egill; Larsson, H.B.;

    1999-01-01

    The blood oxygenation level-dependent (BOLD) effect in functional magnetic resonance imaging depends on at least partial uncoupling between cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO2) changes. By measuring CBF and BOLD simultaneously, the relative change in CMRO2 can b...

  15. Correlation of glucose metabolism in brain cells and brain morphological changes with clinical typing in children with cerebral palsy

    Institute of Scientific and Technical Information of China (English)

    Qiongxiang Zhai; Huixian Qiao; Jiqing Liu

    2006-01-01

    BACKGROUND:It is widely known that fluorino-18-fluorodeoxyglucose positron emission tomography(18F-FDG PET)is commonly used to evaluate and diagnose epilepsy;however,whether it is beneficial to understand functional metabolism of bra in cells so as to reflect injured site and degree of brain cells or not should be studied further.OBJECTIVE:To evaluate the correlation between glucose metabolism and clinical typling as well as the conelation between active function of brain cells and degree of brain injury among children with cerbral palsy with 18F-FDG PET and MRI and compare the results of them.DESIGN:Case analysis.SETTING:Department of Pediatrics,People's Hospital of Guangdong Province.PARTICIPANTS:A total of 31 children with cerebral palsy were selected from Out-patient Clinic and In-patient Department of People's Hospital of Guangdong Province from July 2001 to August 2004.Based on clinical criteria of cerebral palsy,patients were classified into spasm(n=10),gradual movement(n=4),mixed type(n =13)and ataxia(n=4).There were 18 boys and 13 girls aged from 10 months to 4 years.All of them were met the diagnostic criteria of cerebral palsy and all parents of them were told the facts.Exclusion cdteria:Patients who had cerebral palsy caused by genetic metabolism disease were excluded.METHODS:①All children accepted MRI examination after hospitalization with Philips Acs NT 15T superconductling magnetic resonance scanner.②All children were fasted for 4 hours.And then,PET image of brain was collected based on T+EID type.If obvious hypermetabolism or hypometabolism region successively occurred on two layers, the image was regarded as abnormality. ③Different correlations of various abnormal greups of MRI and vadous types of cerebral palsy with PET image were compared and analyzed with Erusal-Willas rank sum test.MAIN OUTCOME MEASURES:①Results of 18F-FDG PET;②Results of MRI examination;③Correlation of variously abnormal groups of MRI and various types of cerebral

  16. Metabolic pathway analysis of Scheffersomyces (Pichia) stipitis. Effect of oxygen availability on ethanol synthesis and flux distributions

    Energy Technology Data Exchange (ETDEWEB)

    Unrean, Pornkamol [King Mongkut' s Univ. of Technology Thonburi, Bangkok (Thailand). Biochemical Engineering and Pilot Plant Research and Development Unit; National Center for Genetik Engineering and Biotechnology (BIOTEC), Pathumtani (Thailand); Nguyen, Nhung H.A. [King Mongkut' s Univ. of Technology Thonburi, Bangkok (Thailand). Biochemical Engineering and Pilot Plant Research and Development Unit

    2012-06-15

    Elementary mode analysis (EMA) identifies all possible metabolic states of the cell metabolic network. Investigation of these states can provide a detailed insight into the underlying metabolism in the cell. In this study, the flux states of Scheffersomyces (Pichia) stipitis metabolism were examined. It was shown that increasing oxygen levels led to a decrease of ethanol synthesis. This trend was confirmed by experimental evaluation of S. stipitis in glucose-xylose fermentation. The oxygen transfer rate for an optimal ethanol production was 1.8 mmol/l/h, which gave the ethanol yield of 0.40 g/g and the ethanol productivity of 0.25 g/l/h. For a better understanding of the cell's regulatory mechanism in response to oxygenation levels, EMA was used to examine metabolic flux patterns under different oxygen levels. Up- and downregulation of enzymes in the network during the change of culturing condition from oxygen limitation to oxygen sufficiency were identified. The results indicated the flexibility of S. stipitis metabolism to cope with oxygen availability. In addition, relevant genetic targets towards improved ethanol-producing strains under all oxygenation levels were identified. These targeted genes limited the metabolic functionality of the cell to function according to the most efficient ethanol synthesis pathways. The presented approach is promising and can contribute to the development of culture optimization and strain engineers for improved lignocellulosic ethanol production by S. stipitis. (orig.)

  17. Effects of various anesthetic techniques and PaCO2 levels on cerebral oxygen balance in neurosurgical patients

    Institute of Scientific and Technical Information of China (English)

    陈绍洋; 王强; 熊利泽; 胡胜; 曾祥龙

    2003-01-01

    Objective: To assess the effects of various anesthetic techniques and PaCO2 levels on cerebral oxygen supply/consumption balance during craniotomy for removal of tumors, and to explore an anesthetic technique for neurosurgery and an appropriate degree of PaCO2 during neuroanesthesia. Methods: One hundred and fourteen patients with supratentorial tumors for elective craniotomy, ASA grade Ⅰ-Ⅱ, were randomly allocated to six groups. Patients were anesthetized with continuous intravenous infusion of 2% procaine 1.0 mg*kg-1*min-1 in Group Ⅰ, inhalation of 1.0%-1.5% isoflurane in Group Ⅱ, and infusion of 2% procaine 0.5 mg*kg-1*min-1 combined with inhalation of 0.5%-0.7% isoflurane in Group Ⅲ during the period of study. The end-tidal pressure of CO2 (PET CO2 )was maintained at 4.0 kPa in these 3 groups. In Group Ⅳ, Ⅴ and Ⅵ, the anesthetic technique was the same as that in Group Ⅰ but the PETCO2 was adjusted to 3.5, 4.0 and 4.5 kPa respectively for 60 min during which the study was performed. The radial arterial and retrograde jugular venous blood samples were obtained at the onset and the end of this study for determining jugular venous bulb oxygen saturation (SjvO2), arteriovenous oxygen content difference (AVDO2) and cerebral extraction of oxygen (CEO2). Results: In Group Ⅰ and Ⅲ SjvO2, AVDO2 and CEO2 remained stable. Although SjvO2 kept constant, AVDO2 and CEO2 decreased significantly (P<0.05) in Group Ⅱ. Moreover, AVDO2 and CEO2 in Group Ⅱ were significantly lower than those of Group Ⅲ (P<0.05). In Group Ⅳ, 60 min after hyperventilation, SjvO2 and jugular venous oxygen content(CjvO2) decreased markedly (P<0.01) while CEO2 increased significantly (P<0.01). In addition, SjvO2, CjvO2 and CEO2 in Group Ⅳ were significantly different from the corresponding parameters in Group Ⅴ and Group Ⅵ (P<0.05). In view of sustained excessive hyperventilation, SjvO2 was less than 50% in 37.5% patients of Group Ⅳ. Conclusion: Anesthesia with

  18. Activity-dependent increases in local oxygen consumption correlate with post-synaptic currents in the mouse cerebellum in vivo

    DEFF Research Database (Denmark)

    Mathiesen, Claus; Caesar, Kirsten; Thomsen, Kirsten Joan

    2011-01-01

    Evoked neural activity correlates strongly with rises in cerebral metabolic rate of oxygen (CMRO2) and cerebral blood flow. Activity-dependent rises in CMRO2 fluctuate with ATP turnover due to ion pumping. In vitro studies suggest that increases in cytosolic Ca2+ stimulate oxidative metabolism vi...

  19. The influence of ultraviolet blood irradiation and oxygenation on oxygen free radicals metabolism in rabbits with soman intoxication

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Objective: To investigate the effect of ultraviolet blood irradiation and oxygenation (UBIO) on the metabolism of oxygen free radicals in rabbits with acute soman intoxication. Methods: One hundred rabbits were randomly divided into 5 groups: normal control group, intoxication group, routine therapy group, UBIO therapy group and combined therapy group. After 14 d, the concentration of malondiadehyde (MDA) and activity of superoxide dismutase (SOD), glutathionperoxidase (GSH-Px), catalase (CAT)and total antioxidative capacity (T-AOC) in serum were determined respectively. Results: Compared with the normal control group, the concentration of MDA and activity of CAT in the intoxication group were significantly higher (P < 0. 05 ), but SOD, GSH-Px activity and T-AOC were significantly lower (P<0.05). After UBIO or combined therapy, serum MDA level was significantly lower in comparison with intoxication group (P<0.05), but the activity of SOD, GSH-Px, CAT and T AOC were higher than intoxication group(P<0.05). Conclusion: There is an obvious oxygen free radical injury in rabbits with acute soman intoxication. UBIO can improve the antioxidation ability of rabbits and may be applied to treat acute soman intoxication as adjunctive therapy.

  20. Changes in cerebral haemodynamics, regional oxygen saturation and amplitude-integrated continuous EEG during hypoxia-ischaemia and reperfusion in newborn piglets

    NARCIS (Netherlands)

    Ioroi, T; Peeters-Scholte, C; Post, [No Value; Groenendaal, F; van Bel, F

    2002-01-01

    Perinatal asphyxia models are necessary to obtain knowledge of the pathophysiology of hypoxia-ischaemia (HI) and to test potential neuroprotective strategies. The present study was performed in newborn piglets to obtain information about simultaneous changes in cerebral oxygenation and haemodynamics

  1. 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…

  2. Low oxygen level increases proliferation and metabolic changes in bovine granulosa cells.

    Science.gov (United States)

    Shiratsuki, Shogo; Hara, Tomotaka; Munakata, Yasuhisa; Shirasuna, Koumei; Kuwayama, Takehito; Iwata, Hisataka

    2016-12-05

    The present study addresses molecular backgrounds underlying low oxygen induced metabolic changes and 1.2-fold change in bovine granulosa cell (GCs) proliferation. RNA-seq revealed that low oxygen (5%) upregulated genes associated with HIF-1 and glycolysis and downregulated genes associated with mitochondrial respiration than that in high oxygen level (21%). Low oxygen level induced high glycolytic activity and low mitochondrial function and biogenesis. Low oxygen level enhanced GC proliferation with high expression levels of HIF-1, VEGF, AKT, mTOR, and S6RP, whereas addition of anti-VEGF antibody decreased cellular proliferation with low phosphorylated AKT and mTOR expression levels. Low oxygen level reduced SIRT1, whereas activation of SIRT1 by resveratrol increased mitochondrial replication and decreased cellular proliferation with reduction of phosphorylated mTOR. These results suggest that low oxygen level stimulates the HIF1-VEGF-AKT-mTOR pathway and up-regulates glycolysis, which contributes to GC proliferation, and downregulation of SIRT1 contributes to hypoxia-associated reduction of mitochondria and cellular proliferation.

  3. Quantitative metabolomics analysis of amino acid metabolism in recombinant Pichia pastoris under different oxygen availability conditions

    Directory of Open Access Journals (Sweden)

    Carnicer Marc

    2012-06-01

    Full Text Available Abstract Background Environmental and intrinsic stress factors can result in the global alteration of yeast physiology, as evidenced by several transcriptional studies. Hypoxia has been shown to have a beneficial effect on the expression of recombinant proteins in Pichia pastoris growing on glucose. Furthermore, transcriptional profiling analyses revealed that oxygen availability was strongly affecting ergosterol biosynthesis, central carbon metabolism and stress responses, in particular the unfolded protein response. To contribute to the better understanding of the effect and interplay of oxygen availability and foreign protein secretion on central metabolism, a first quantitative metabolomic analysis of free amino acids pools in a recombinant P. pastoris strain growing under different oxygen availability conditions has been performed. Results The values obtained indicate significant variations in the intracellular amino acid pools due to different oxygen availability conditions, showing an overall increase of their size under oxygen limitation. Notably, even while foreign protein productivities were relatively low (about 40–80 μg Fab/gDCW·h, recombinant protein production was found to have a limited but significant impact on the intracellular amino acid pools, which were generally decreased in the producing strain compared with the reference strain. However, observed changes in individual amino acids pools were not correlated with their corresponding relative abundance in the recombinant protein sequence, but to the overall cell protein amino acid compositional variations. Conclusions Overall, the results obtained, combined with previous transcriptomic and proteomic analyses provide a systematic metabolic fingerprint of the oxygen availability impact on recombinant protein production in P. pastoris.

  4. Metabolic Characterization of Acutely Isolated Hippocampal and Cerebral Cortical Slices Using [U-(13)C]Glucose and [1,2-(13)C]Acetate as Substrates

    DEFF Research Database (Denmark)

    McNair, Laura F; Kornfelt, Rasmus; Walls, Anne B;

    2016-01-01

    Brain slice preparations from rats, mice and guinea pigs have served as important tools for studies of neurotransmission and metabolism. While hippocampal slices routinely have been used for electrophysiology studies, metabolic processes have mostly been studied in cerebral cortical slices. Few c...

  5. Alterations in Cerebral Cortical Glucose and Glutamine Metabolism Precedes Amyloid Plaques in the APPswe/PSEN1dE9 Mouse Model of Alzheimer's Disease

    DEFF Research Database (Denmark)

    Andersen, Jens V; Christensen, Sofie K; Aldana, Blanca I;

    2016-01-01

    Alterations in brain energy metabolism have been suggested to be of fundamental importance for the development of Alzheimer's disease (AD). However, specific changes in brain energetics in the early stages of AD are poorly known. The aim of this study was to investigate cerebral energy metabolism...

  6. Studies of cerebral blood flow and metabolism in patients with senile dementia of the Alzheimer's type and diagnostic evaluation of the dementing illnesses by positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Sakamoto, Shizuki (Nippon Medical School, Tokyo (Japan))

    1990-06-01

    This study was designed to determine cerebral dysfunction in senile dementia of the Alzheimer's type (SDAT). Regional cerebral blood flow (rCBF), oxygen extraction fraction and cerebral oxygen consumption (rCMRO{sub 2}) were studied in SDAT patients (n=16) and age-matched normal elderly people (n=5) by positron emission tomography (PET) using the O-15 labeled CO{sub 2} and O{sub 2} inhalation technique. The SDAT group had a significantly lower values in both rCBF and rCMRO{sub 2} than the normal control. During the early stage of SDAT, rCMRO{sub 2} was restricted to the temporal cortex; and it extended to the parietal and frontal cortices associated with a decreased rCBF as the disease progressed. Posterior temporal and posterior parietal association cortices were considered to be the most damageable part during the early stage. Bilateral differences in oxygen metabolism of the temporal and parietal cortices tended to be in accordance with clinical symptoms for disturbed speech and visuospatial function, suggesting the correlation between rCMRO{sub 2} and rCBF in SDAT. Findings of PET in SDAT differed from those obtained in each patient with multi-infarct dementia or Pick disease, in that both rCBF and rCMRO{sub 2} were inhomogeneously decreased over the whole cerebral cortex for multi-infarct dementia and in that homogeneously decreased rCBF and rCMRO{sub 2} were restricted to the frontal and temporal cortices for Pick disease. PET may have a potential for differentiating various types of dementia. (N.K.).

  7. 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

  8. Visible-light OCT to quantify retinal oxygen metabolism (Conference Presentation)

    Science.gov (United States)

    Zhang, Hao F.; Yi, Ji; Chen, Siyu; Liu, Wenzhong; Soetikno, Brian T.

    2016-03-01

    We explored, both numerically and experimentally, whether OCT can be a good candidate to accurately measure retinal oxygen metabolism. We first used statistical methods to numerically simulate photon transport in the retina to mimic OCT working under different spectral ranges. Then we analyze accuracy of OCT oximetry subject to parameter variations such as vessel size, pigmentation, and oxygenation. We further developed an experimental OCT system based on the spectral range identified by our simulation work. We applied the newly developed OCT to measure both retinal hemoglobin oxygen saturation (sO2) and retinal retinal flow. After obtaining the retinal sO2 and blood velocity, we further measured retinal vessel diameter and calculated the retinal oxygen metabolism rate (MRO2). To test the capability of our OCT, we imaged wild-type Long-Evans rats ventilated with both normal air and air mixtures with various oxygen concentrations. Our simulation suggested that OCT working within visible spectral range is able to provide accurate measurement of retinal MRO2 using inverse Fourier transform spectral reconstruction. We called this newly developed technology vis-OCT, and showed that vis-OCT was able to measure the sO2 value in every single major retinal vessel around the optical disk as well as in micro retinal vessels. When breathing normal air, the averaged sO2 in arterial and venous blood in Long-Evans rats was measured to be 95% and 72%, respectively. When we challenge the rats using air mixtures with different oxygen concentrations, vis-OCT measurement followed analytical models of retinal oxygen diffusion and pulse oximeter well.

  9. [Dynamic variance of intracellular metabolic energies under rhythmical control for dissolved oxygen in PHB mixed cultivation].

    Science.gov (United States)

    Qian, Z W; Tohyama, M; Hua, Q; Shimizu, K

    2001-07-01

    The mixed cultivation using cheaper carbon source-wasted food material contained glucose and lactate at the same time was conducted in 5L fermentor, within which glucose was converted to lactate by L. delbrueckii in anaerobic condition and the lactate was converted to PHB by R. eutropha in aerobic condition. Considering dissolved oxygen concentration may affect the level of intracellular ATP and NADPH of the metabolic pathways for R. eutropha in lactate under autotrophy or heterotrophy, rhythmical oscillated control for DO based on chaos control method was consequently presented. This method was employed to satisfy two strains for opposite oxygen preferences, moreover, excite the intracellular metabolic energy simultaneously. The values examined through spectrophotofluorimetry represented that both ATP and NADPH exhibited fluctuations in accordance with the DO rhythm. By means of this control design, the concentration of PHB can be doubled than the usual under stable DO control.

  10. The Effect of Patient-Specific Cerebral Oxygenation Monitoring on Postoperative Cognitive Function: A Multicenter Randomized Controlled Trial

    Science.gov (United States)

    Ellis, Lucy; Murphy, Gavin J; Culliford, Lucy; Dreyer, Lucy; Clayton, Gemma; Downes, Richard; Nicholson, Eamonn; Stoica, Serban; Reeves, Barnaby C

    2015-01-01

    Background Indices of global tissue oxygen delivery and utilization such as mixed venous oxygen saturation, serum lactate concentration, and arterial hematocrit are commonly used to determine the adequacy of tissue oxygenation during cardiopulmonary bypass (CPB). However, these global measures may not accurately reflect regional tissue oxygenation and ischemic organ injury remains a common and serious complication of CPB. Near-infrared spectroscopy (NIRS) is a noninvasive technology that measures regional tissue oxygenation. NIRS may be used alongside global measures to optimize regional perfusion and reduce organ injury. It may also be used as an indicator of the need for red blood cell transfusion in the presence of anemia and tissue hypoxia. However, the clinical benefits of using NIRS remain unclear and there is a lack of high-quality evidence demonstrating its efficacy and cost effectiveness. Objective The aim of the patient-specific cerebral oxygenation monitoring as part of an algorithm to reduce transfusion during heart valve surgery (PASPORT) trial is to determine whether the addition of NIRS to CPB management algorithms can prevent cognitive decline, postoperative organ injury, unnecessary transfusion, and reduce health care costs. Methods Adults aged 16 years or older undergoing valve or combined coronary artery bypass graft and valve surgery at one of three UK cardiac centers (Bristol, Hull, or Leicester) are randomly allocated in a 1:1 ratio to either a standard algorithm for optimizing tissue oxygenation during CPB that includes a fixed transfusion threshold, or a patient-specific algorithm that incorporates cerebral NIRS monitoring and a restrictive red blood cell transfusion threshold. Allocation concealment, Internet-based randomization stratified by operation type and recruiting center, and blinding of patients, ICU and ward care staff, and outcome assessors reduce the risk of bias. The primary outcomes are cognitive function 3 months after

  11. The cerebral metabolism of amino acids and related metabolites as studied by {sup 13}C and {sup 14}C labelling

    Energy Technology Data Exchange (ETDEWEB)

    Hassel, B.

    1995-11-01

    The present investigations show the feasibility of analyzing the cerebral metabolism of amino acids and related metabolites by {sup 13}C-and {sup 14}C-labelling using labelled acetate and glucose as markers for glial and neuronal metabolism, respectively. Using [{sup 13}C]acetate, it was shown that glial cells export {approx}60% of their TCA cycle intermediates, mostly as glutamine, and that this glutamine is used by neurons partly as an energy reserve, and partly it is converted directly to glutamate and GABA. Using [{sup 13}C]glucose, the glial process or pyruvate carboxylation was shown to compensate fully for the loss of glutamine. The mechanism of action of two neurotoxins, fluorocitrate and 3-nitropropionate was elucidated. The latter toxin was shown to inhibit the TCA cycle of GABAergic neurons selectively. Formation of pyruvate and lactate from glial TCA cycle intermediates was demonstrated in vivo. This pathway may be important for glial inactivation of transmitter glutamate and GABA. The results illustrate glianeuronal interactions, and they suggest the applicability of {sup 13}CNMR spectroscopy to the detailed study of the cerebral metabolism of amino acids in the intact, unanesthetized human brain. 174 refs.

  12. [Effect of solcoseryl on oxygen metabolism and growth of experimental tumors].

    Science.gov (United States)

    Mosienko, V S; Zagoruĭko, L I; Todor, I N; Khasanova, L T

    1987-01-01

    Antihypoxant and antitumour properties of solcoseryl were studied on intact and tumour-bearing rats and mice. By the polarographic method it is found that solcoseryl increases the oxygen metabolism only in animal hypoxic tissues and improves, probably, energy production of their mitochondria. On many tumour strains it is shown that the injections of solcoseryl decelerate the growth of some tumours, inhibit the metastatic process and produce no toxic effect on the animals.

  13. Optimal concentration and time window for proliferation and differentiation of neural stem cells from embryonic cerebral cortex:5% oxygen preconditioning for 72 hours

    Institute of Scientific and Technical Information of China (English)

    Li-li Yuan; Ying-jun Guan; Deng-dian Ma; Hong-mei Du

    2015-01-01

    Hypoxia promotes proliferation and differentiation of neural stem cells from embryonic day 12 rat brain tissue, but the concentration and time of hypoxic preconditioning are controversial. To address this, we cultured neural stem cells isolated from embryonic day 14 rat cerebral cortex in 5% and 10% oxygenin vitro. MTT assay, neurosphere number, and immunolfuorescent staining found that 5% or 10% oxygen preconditioning for 72 hours improved neural stem cell viability and proliferation. With prolonged hypoxic duration (120 hours), the proportion of apoptotic cells increased. Thus, 5% oxygen preconditioning for 72 hours promotes neural stem cell prolif-eration and neuronal differentiation. Our ifndings indicate that the optimal concentration and duration of hypoxic preconditioning for promoting proliferation and differentiation of neural stem cells from the cerebral cortex are 5% oxygen for 72 hours.

  14. Episodes of apnea and bradycardia in the preterm newborn: impact on cerebral oxygenation measured by near-infrared spectrophotometry

    Science.gov (United States)

    Van Huffel, Sabine; Craemers, Johan; Lenaerts, Bart; Daniels, Hans; Naulaers, Gunnar; Casaer, Paul

    1998-12-01

    The objective of this study is to evaluate the effect of episodes of apneas and/or mild bradycardia (heart rate decreases of 10 to 20% or more) on cerebral oxyhemoglobin (HbO2) and reduced hemoglobin (Hb) concentration as measured by Near Infrared Spectrophotometry (NIRS). Measurements were carried out on 7 preterm infants who experienced apneic and bradycardiac events. It is shown how to characterize these events using time-frequency analysis. In addition to NIRS (performed with a NIRO-500 from Hamamatsu, Japan), the heart rate, ECG, peripheral arterial oxygen saturation (measured at the foot) and respiration (abdominal and thoracic pressure, and nasal airflow) were continuously recorded. The impact of apneic events and periodic breathing on these measurements reveals the clinical relevance of NIRS. In particular, we investigate whether these changes in heart rate and respiration also influence HbO2 and reduced Hb concentration in neonatal brain. These changes are characterized, as well as their relationships with the other simultaneously recorded signals such as peripheral arterial oxygen saturation.

  15. Comparable cerebral oxygenation patterns in younger and older adults during dual-task walking with increasing load

    Directory of Open Access Journals (Sweden)

    Sarah A. Fraser

    2016-10-01

    Full Text Available The neuroimaging literature on dual-task gait clearly demonstrates increased prefrontal cortex (PFC involvement when performing a cognitive task while walking. However, findings from direct comparisons of the cerebral oxygenation patterns of younger (YA and older (OA adults during dual-task walking are mixed and it is unclear how YA and OA respond to increasing cognitive load (difficulty while walking. This functional near infra-red (fNIRS study examined cerebral oxygenation of YA and OA during self-paced dual-task treadmill walking at two different levels of cognitive load (auditory n-back. Changes in accuracy (% as well as oxygenated (HbO and deoxygenated (HbR hemoglobin were examined. For the HbO and HbR measures, eight regions of interest (ROIs were assessed: the anterior and posterior dorsolateral and ventrolateral PFC (aDLPFC, pDLPFC, aVLPFC, pVLPFC in each hemisphere. Nineteen YA (M = 21.83 yrs and 14 OA (M = 66.85 yrs walked at a self-selected pace while performing auditory 1-back and 2-back tasks. Walking alone (single motor: SM and performing the cognitive tasks alone (single cognitive: SC were compared to dual-task walking (DT = SM + SC. In the behavioural data, participants were more accurate in the lowest level of load (1-back compared to the highest (2-back; p ˂ .001. YA were more accurate than OA overall (p = .009, and particularly in the 2-back task (p = .048. In the fNIRS data, both younger and older adults had task effects (SM < DT in specific ROIs for ∆HbO (3 YA, 1 OA and ∆HbR (7 YA, 8 OA. After controlling for walk speed differences, direct comparisons between YA and OA did not reveal significant age differences, but did reveal a difficulty effect in HbO in the left aDLPFC (p = .028 and significant task effects (SM < DT in HbR for 6 of the 8 ROIs. Findings suggest that YA and OA respond similarly to manipulations of cognitive load when walking on a treadmill at a self-selected pace.

  16. Changes in cerebral oxidative metabolism in patients with acute liver failure

    DEFF Research Database (Denmark)

    Bjerring, P N; Larsen, F S

    2013-01-01

    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...

  17. Association between fatigue and failure to preserve cerebral energy turnover during prolonged exercise

    DEFF Research Database (Denmark)

    Nybo, Lars; Møller, Kirsten; Pedersen, Bente Klarlund

    2003-01-01

    AIM: This study evaluated if the fatigue and apathy arising during exercise with hypoglycaemia could relate to a lowering of the cerebral metabolic rates of glucose and oxygen. METHODS AND RESULTS: Six males completed 3 h of cycling with or without glucose supplementation in random order. Cerebral...... was accompanied by a lowering of the cerebral metabolic rate of oxygen from 1.84 +/- 0.19 mmol g(-1) min(-)1 during exercise with glucose supplementation to 1.60 +/- 0.16 mmol g(-1) min(-1) during hypoglycaemia (P

  18. Integration of Carbon, Nitrogen, and Oxygen Metabolism in Escherichia coli--Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Rabinowitz, Joshua D; Wingreen, Ned s; Rabitz, Herschel A; Xu, Yifan

    2012-10-22

    A key challenge for living systems is balancing utilization of multiple elemental nutrients, such as carbon, nitrogen, and oxygen, whose availability is subject to environmental fluctuations. As growth can be limited by the scarcity of any one nutrient, the rate at which each nutrient is assimilated must be sensitive not only to its own availability, but also to that of other nutrients. Remarkably, across diverse nutrient conditions, E. coli grows nearly optimally, balancing effectively the conversion of carbon into energy versus biomass. To investigate the link between the metabolism of different nutrients, we quantified metabolic responses to nutrient perturbations using LC-MS based metabolomics and built differential equation models that bridge multiple nutrient systems. We discovered that the carbonaceous substrate of nitrogen assimilation, -ketoglutarate, directly inhibits glucose uptake and that the upstream glycolytic metabolite, fructose-1,6-bisphosphate, ultrasensitively regulates anaplerosis to allow rapid adaptation to changing carbon availability. We also showed that NADH controls the metabolic response to changing oxygen levels. Our findings support a general mechanism for nutrient integration: limitation for a nutrient other than carbon leads to build-up of the most closely related product of carbon metabolism, which in turn feedback inhibits further carbon uptake.

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

    DEFF Research Database (Denmark)

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

    2016-01-01

    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...

  20. 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...

  1. Inspired Carbon Dioxide During Hypoxia: Effects on Task Performance and Cerebral Oxygen Saturation

    NARCIS (Netherlands)

    Dorp, E. van; Los, M.; Dirven, P.; Sarton, E.; Valk, P.; Teppema, L.; Stienstra, R.; Dahan, A.

    2007-01-01

    Introduction: Exposure to a hypoxic environment has a deleterious effect on physiological and mental functions. We studied the effect of added inspired CO2 during artificially induced hypoxic normobaric hypoxia (oxygen saturation ∼80%) on complex task performance. Methods: In random order, 22 health

  2. Metabolic pattern of the acute phase of subarachnoid hemorrhage in a novel porcine model: studies with cerebral microdialysis with high temporal resolution.

    Directory of Open Access Journals (Sweden)

    Christoffer Nyberg

    Full Text Available BACKGROUND: Aneurysmal subarachnoid hemorrhage (SAH may produce cerebral ischemia and systemic responses including stress. To study immediate cerebral and systemic changes in response to aneurysm rupture, animal models are needed. OBJECTIVE: To study early cerebral energy changes in an animal model. METHODS: Experimental SAH was induced in 11 pigs by autologous blood injection to the anterior skull base, with simultaneous control of intracranial and cerebral perfusion pressures. Intracerebral microdialysis was used to monitor concentrations of glucose, pyruvate and lactate. RESULTS: In nine of the pigs, a pattern of transient ischemia was produced, with a dramatic reduction of cerebral perfusion pressure soon after blood injection, associated with a quick glucose and pyruvate decrease. This was followed by a lactate increase and a delayed pyruvate increase, producing a marked but short elevation of the lactate/pyruvate ratio. Glucose, pyruvate, lactate and lactate/pyruvate ratio thereafter returned toward baseline. The two remaining pigs had a more severe metabolic reaction with glucose and pyruvate rapidly decreasing to undetectable levels while lactate increased and remained elevated, suggesting persisting ischemia. CONCLUSION: The animal model simulates the conditions of SAH not only by deposition of blood in the basal cisterns, but also creating the transient global ischemic impact of aneurysmal SAH. The metabolic cerebral changes suggest immediate transient substrate failure followed by hypermetabolism of glucose upon reperfusion. The model has features that resemble spontaneous bleeding, and is suitable for future research of the early cerebral and systemic responses to SAH that are difficult to study in humans.

  3. Cytochrome c oxidase response to changes in cerebral oxygen delivery in the adult brain shows higher brain-specificity than haemoglobin ☆

    OpenAIRE

    Kolyva, Christina; Ghosh, Arnab; Tachtsidis, Ilias; Highton, David; Chris E Cooper; Smith, Martin; Elwell, Clare 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...

  4. The role of oxygen in yeast metabolism during high cell density brewery fermentations.

    Science.gov (United States)

    Verbelen, P J; Saerens, S M G; Van Mulders, S E; Delvaux, F; Delvaux, F R

    2009-04-01

    The volumetric productivity of the beer fermentation process can be increased by using a higher pitching rate (i.e., higher inoculum size). However, the decreased yeast net growth observed in these high cell density fermentations can have a negative impact on the physiological stability throughout subsequent yeast generations. The use of different oxygen conditions (wort aeration, wort oxygenation, yeast preoxygenation) was investigated to improve the growth yield during high cell density fermentations and yeast metabolic and physiological parameters were assessed systematically. Together with a higher extent of growth (dependent on the applied oxygen conditions), the fermentation power and the formation of unsaturated fatty acids were also affected. Wort oxygenation had a significant decreasing effect on the formation of esters, which was caused by a decreased expression of the alcohol acetyl transferase gene ATF1, compared with the other conditions. Lower glycogen and trehalose levels at the end of fermentation were observed in case of the high cell density fermentations with oxygenated wort and the reference fermentation. The expression levels of BAP2 (encoding the branched chain amino acid permease), ERG1 (encoding squalene epoxidase), and the stress responsive gene HSP12 were predominantly influenced by the high cell concentrations, while OLE1 (encoding the fatty acid desaturase) and the oxidative stress responsive genes SOD1 and CTT1 were mainly affected by the oxygen availability per cell. These results demonstrate that optimisation of high cell density fermentations could be achieved by improving the oxygen conditions, without drastically affecting the physiological condition of the yeast and beer quality.

  5. Metabolic scaling theory in plant biology and the three oxygen paradoxa of aerobic life.

    Science.gov (United States)

    Kutschera, Ulrich; Niklas, Karl J

    2013-12-01

    Alfred Russell Wallace was a field naturalist with a strong interest in general physiology. In this vein, he wrote that oxygen (O2), produced by green plants, is "the food of protoplasm, without which it cannot continue to live". Here we summarize current models relating body size to respiration rates (in the context of the metabolic scaling theory) and show that oxygen-uptake activities, measured at 21 vol.% O2, correlate closely with growth patterns at the level of specific organs within the same plant. Thus, whole plant respiration can change ontogenetically, corresponding to alterations in the volume fractions of different tissues. Then, we describe the evolution of cyanobacterial photosynthesis during the Paleoarchean, which changed the world forever. By slowly converting what was once a reducing atmosphere to an oxidizing one, microbes capable of O2-producing photosynthesis modified the chemical nature and distribution of the element iron (Fe), slowly drove some of the most ancient prokaryotes to extinction, created the ozone (O3) layer that subsequently shielded the first terrestrial plants and animals from harmful UV radiation, but also made it possible for Earth's forest to burn, sometimes with catastrophic consequences. Yet another paradox is that the most abundant protein (i.e., the enzyme Rubisco, Ribulose-1,5-biphosphate carboxylase/oxygenase) has a greater affinity for oxygen than for carbon dioxide (CO2), even though its function is to bind with the latter rather than the former. We evaluate this second "oxygen paradox" within the context of photorespiratory carbon loss and crop yield reduction in C3 vs. C4 plants (rye vs. maize). Finally, we analyze the occurrence of reactive oxygen species (ROS) as destructive by-products of cellular metabolism, and discuss the three "O2-paradoxa" with reference to A. R. Wallace's speculations on "design in nature".

  6. Reconstruction and flux analysis of coupling between metabolic pathways of astrocytes and neurons: application to cerebral hypoxia

    Directory of Open Access Journals (Sweden)

    Akιn Ata

    2007-12-01

    Full Text Available Abstract Background It is a daunting task to identify all the metabolic pathways of brain energy metabolism and develop a dynamic simulation environment that will cover a time scale ranging from seconds to hours. To simplify this task and make it more practicable, we undertook stoichiometric modeling of brain energy metabolism with the major aim of including the main interacting pathways in and between astrocytes and neurons. Model The constructed model includes central metabolism (glycolysis, pentose phosphate pathway, TCA cycle, lipid metabolism, reactive oxygen species (ROS detoxification, amino acid metabolism (synthesis and catabolism, the well-known glutamate-glutamine cycle, other coupling reactions between astrocytes and neurons, and neurotransmitter metabolism. This is, to our knowledge, the most comprehensive attempt at stoichiometric modeling of brain metabolism to date in terms of its coverage of a wide range of metabolic pathways. We then attempted to model the basal physiological behaviour and hypoxic behaviour of the brain cells where astrocytes and neurons are tightly coupled. Results The reconstructed stoichiometric reaction model included 217 reactions (184 internal, 33 exchange and 216 metabolites (183 internal, 33 external distributed in and between astrocytes and neurons. Flux balance analysis (FBA techniques were applied to the reconstructed model to elucidate the underlying cellular principles of neuron-astrocyte coupling. Simulation of resting conditions under the constraints of maximization of glutamate/glutamine/GABA cycle fluxes between the two cell types with subsequent minimization of Euclidean norm of fluxes resulted in a flux distribution in accordance with literature-based findings. As a further validation of our model, the effect of oxygen deprivation (hypoxia on fluxes was simulated using an FBA-derivative approach, known as minimization of metabolic adjustment (MOMA. The results show the power of the

  7. Myocardial Oxidative Metabolism and Protein Synthesis during Mechanical Circulatory Support by Extracorporeal Membrane Oxygenation

    Energy Technology Data Exchange (ETDEWEB)

    Priddy, MD, Colleen M.; Kajimoto, Masaki; Ledee, Dolena; Bouchard, Bertrand; Isern, Nancy G.; Olson, Aaron; Des Rosiers, Christine; Portman, Michael A.

    2013-02-01

    Extracorporeal membrane oxygenation (ECMO) provides mechanical circulatory support essential for survival in infants and children with acute cardiac decompensation. However, ECMO also causes metabolic disturbances, which contribute to total body wasting and protein loss. Cardiac stunning can also occur which prevents ECMO weaning, and contributes to high mortality. The heart may specifically undergo metabolic impairments, which influence functional recovery. We tested the hypothesis that ECMO alters oxidative. We focused on the amino acid leucine, and integration with myocardial protein synthesis. We used a translational immature swine model in which we assessed in heart (i) the fractional contribution of leucine (FcLeucine) and pyruvate (FCpyruvate) to mitochondrial acetyl-CoA formation by nuclear magnetic resonance and (ii) global protein fractional synthesis (FSR) by gas chromatography-mass spectrometry. Immature mixed breed Yorkshire male piglets (n = 22) were divided into four groups based on loading status (8 hours of normal circulation or ECMO) and intracoronary infusion [13C6,15N]-L-leucine (3.7 mM) alone or with [2-13C]-pyruvate (7.4 mM). ECMO decreased pulse pressure and correspondingly lowered myocardial oxygen consumption (~ 40%, n = 5), indicating decreased overall mitochondrial oxidative metabolism. However, FcLeucine was maintained and myocardial protein FSR was marginally increased. Pyruvate addition decreased tissue leucine enrichment, FcLeucine, and Fc for endogenous substrates as well as protein FSR. Conclusion: The heart under ECMO shows reduced oxidative metabolism of substrates, including amino acids, while maintaining (i) metabolic flexibility indicated by ability to respond to pyruvate, and (ii) a normal or increased capacity for global protein synthesis, suggesting an improved protein balance.

  8. Reactive oxygen species in the paraventricular nucleus of the hypothalamus alter sympathetic activity during metabolic syndrome.

    Directory of Open Access Journals (Sweden)

    JOSIANE CAMPOS CRUZ

    2015-12-01

    Full Text Available The paraventricular nucleus of the hypothalamus (PVN contains heterogeneous populations of neurons involved in autonomic and neuroendocrine regulation. The PVN plays an important role in the sympathoexcitatory response to increasing circulating levels of angiotensin II (Ang-II, which activates AT1 receptors in the circumventricular organs (OCVs, mainly in the subfornical organ (SFO. Circulating Ang-II induces a de novo synthesis of Ang-II in SFO neurons projecting to pre-autonomic PVN neurons. Activation of AT1 receptors induces intracellular increases in reactive oxygen species (ROS, leading to increases in sympathetic nerve activity (SNA. Chronic sympathetic nerve activation promotes a series of metabolic disorders that characterizes the metabolic syndrome (MetS: dyslipidemia, hyperinsulinemia, glucose intolerance, hyperleptinemia and elevated plasma hormone levels, such as noradrenaline, glucocorticoids, leptin, insulin and Ang-II. This review will discuss the contribution of our laboratory and others regarding the sympathoexcitation caused by peripheral Ang-II-induced reactive oxygen species along the subfornical organ and paraventricular nucleus of the hypothalamus. We hypothesize that this mechanism could be involved in metabolic disorders underlying MetS.

  9. Oxygen dependence of metabolic fluxes and energy generation of Saccharomyces cerevisiae CEN.PK113-1A

    Directory of Open Access Journals (Sweden)

    Wiebe Marilyn

    2008-07-01

    Full Text Available Abstract Background The yeast Saccharomyces cerevisiae is able to adjust to external oxygen availability by utilizing both respirative and fermentative metabolic modes. Adjusting the metabolic mode involves alteration of the intracellular metabolic fluxes that are determined by the cell's multilevel regulatory network. Oxygen is a major determinant of the physiology of S. cerevisiae but understanding of the oxygen dependence of intracellular flux distributions is still scarce. Results Metabolic flux distributions of S. cerevisiae CEN.PK113-1A growing in glucose-limited chemostat cultures at a dilution rate of 0.1 h-1 with 20.9%, 2.8%, 1.0%, 0.5% or 0.0% O2 in the inlet gas were quantified by 13C-MFA. Metabolic flux ratios from fractional [U-13C]glucose labelling experiments were used to solve the underdetermined MFA system of central carbon metabolism of S. cerevisiae. While ethanol production was observed already in 2.8% oxygen, only minor differences in the flux distribution were observed, compared to fully aerobic conditions. However, in 1.0% and 0.5% oxygen the respiratory rate was severely restricted, resulting in progressively reduced fluxes through the TCA cycle and the direction of major fluxes to the fermentative pathway. A redistribution of fluxes was observed in all branching points of central carbon metabolism. Yet only when oxygen provision was reduced to 0.5%, was the biomass yield exceeded by the yields of ethanol and CO2. Respirative ATP generation provided 59% of the ATP demand in fully aerobic conditions and still a substantial 25% in 0.5% oxygenation. An extensive redistribution of fluxes was observed in anaerobic conditions compared to all the aerobic conditions. Positive correlation between the transcriptional levels of metabolic enzymes and the corresponding fluxes in the different oxygenation conditions was found only in the respirative pathway. Conclusion 13C-constrained MFA enabled quantitative determination of

  10. Increased interictal cerebral glucose metabolism in a cortical-subcortical network in drug naive patients with cryptogenic temporal lobe epilepsy.

    Science.gov (United States)

    Franceschi, M; Lucignani, G; Del Sole, A; Grana, C; Bressi, S; Minicucci, F; Messa, C; Canevini, M P; Fazio, F

    1995-01-01

    Positron emission tomography with [18F]-2-fluoro-2-deoxy-D-glucose ([18F]FDG) has been used to assess the pattern of cerebral metabolism in different types of epilepsies. However, PET with [18F]FDG has never been used to evaluate drug naive patients with cryptogenic temporal lobe epilepsy, in whom the mechanism of origin and diffusion of the epileptic discharge may differ from that underlying other epilepsies. In a group of patients with cryptogenic temporal lobe epilepsy, never treated with antiepileptic drugs, evidence has been found of significant interictal glucose hypermetabolism in a bilateral neural network including the temporal lobes, thalami, basal ganglia, and cingular cortices. The metabolism in these areas and frontal lateral cortex enables the correct classification of all patients with temporal lobe epilepsy and controls by discriminant function analysis. Other cortical areas--namely, frontal basal and lateral, temporal mesial, and cerebellar cortices--had bilateral increases of glucose metabolism ranging from 10 to 15% of normal controls, although lacking stringent statistical significance. This metabolic pattern could represent a pathophysiological state of hyperactivity predisposing to epileptic discharge generation or diffusion, or else a network of inhibitory circuits activated to prevent the diffusion of the epileptic discharge. PMID:7561924

  11. Effects of tetramethylpyrazine on serum S100β protein, neuron specific enolase, superoxdie dismutase and malondialdehyde content and cerebral oxygen supply-consumption balance and energy metabolism in patients during supratentorial tumor resection%川芎嗪对幕上肿瘤切除术患者血清S100β蛋白、神经元特异性烯醇化酶、超氧化物歧化酶、丙二醇含量及氧供需与能量代谢的影响

    Institute of Scientific and Technical Information of China (English)

    李凤仙; 徐世元; 皇甫秀萍; 张庆国; 许睿; 雷洪伊

    2012-01-01

    Objective To evaluate the effects of intraoperative tetramethylpyrazine infusion on serum S100β protein (S100β),neuron-specific enolase (NSE),superoxdie dismutase (SOD) and malondialdehyde (MDA) content and cerebral oxygen supply-consumption balance and energy metabolism in patients during supratentorial tumor resection.Methods Twenty-four patients undergone supratentorial tumor resection,ASA Ⅰ-Ⅱ degree,age 18-65,were randomly divided into control group (Group A,n=12) and the TMP group (Group B,n=12).Group B received 0.9% sodium chloride 250 ml contained tetramethylpyrazine 80 mg in 20 min when the dural open,while group A was given the same amount of 0.9% sodium chloride.Blood samples were taken from artery and jugular venous bulb simultaneously before induction of anesthesia (T1),after intubation(T2),opening dura instantly (T3),1 h after opening dura (T4),at the closure of dura (T5),and 24 h after operation (T6),for analyzing the blood-gas and calculating the content of artery blood oxygen,saturation of internal jugular venous bulb blood oxygen,content of internal jugular venous bulb blood oxygen,content of artery-internal differences in oxygen and cerebral extraction ratio oxygen.Glucose extraction ratio,cerebral lactate acid extraction rate,lactate oxygen index.Concentration of internal jugular venous bulb serum S100β,NSE,SOD,MDA.The data of mean artery pressure,heart rate,hematocrit and hemoglobin were recorded at the same time intervals.Results ① Compared with T1 [ (36±5)%,(35±5)%] the cerebral extraction ratio oxygen in both groups were significant decrease at T2 [(24±6)%,(25±5)%],but increased at T6 [(42±5)%,(41±6)% ](P<0.05).There were no differences between group A and B at each time intervals.② Compared with T1 [ (6.0±1.0)vol%,(6.4±1.1)vol% ],there were significant decrease at T2 [ (4.2±1.1)vol%,(4.5±1.0)vol% ] for the internal jugular venous bulb blood oxygen in both groups,and also at T5 (5.3±0.8)vol

  12. Cerebral white matter blood flow and energy metabolism in multiple sclerosis

    NARCIS (Netherlands)

    Steen, Christel; D'haeseleer, Miguel; Hoogduin, Johannes M.; Fierens, Yves; Cambron, Melissa; Mostert, Jop P.; Heersema, Dorothea J.; Koch, Marcus W.; De Keyser, Jacques

    2013-01-01

    Background: Cerebral blood flow (CBF) is reduced in normal-appearing white matter (NAWM) of subjects with multiple sclerosis (MS), but the underlying mechanism is unknown. Objective: The objective of this article is to assess the relationship between reduced NAWM CBF and both axonal mitochondrial me

  13. A combination of physical activity and computerized brain training improves verbal memory and increases cerebral glucose metabolism in the elderly

    Science.gov (United States)

    Shah, T; Verdile, G; Sohrabi, H; Campbell, A; Putland, E; Cheetham, C; Dhaliwal, S; Weinborn, M; Maruff, P; Darby, D; Martins, R N

    2014-01-01

    Physical exercise interventions and cognitive training programs have individually been reported to improve cognition in the healthy elderly population; however, the clinical significance of using a combined approach is currently lacking. This study evaluated whether physical activity (PA), computerized cognitive training and/or a combination of both could improve cognition. In this nonrandomized study, 224 healthy community-dwelling older adults (60–85 years) were assigned to 16 weeks home-based PA (n=64), computerized cognitive stimulation (n=62), a combination of both (combined, n=51) or a control group (n=47). Cognition was assessed using the Rey Auditory Verbal Learning Test, Controlled Oral Word Association Test and the CogState computerized battery at baseline, 8 and 16 weeks post intervention. Physical fitness assessments were performed at all time points. A subset (total n=45) of participants underwent [18F] fluorodeoxyglucose positron emission tomography scans at 16 weeks (post-intervention). One hundred and ninety-one participants completed the study and the data of 172 participants were included in the final analysis. Compared with the control group, the combined group showed improved verbal episodic memory and significantly higher brain glucose metabolism in the left sensorimotor cortex after controlling for age, sex, premorbid IQ, apolipoprotein E (APOE) status and history of head injury. The higher cerebral glucose metabolism in this brain region was positively associated with improved verbal memory seen in the combined group only. Our study provides evidence that a specific combination of physical and mental exercises for 16 weeks can improve cognition and increase cerebral glucose metabolism in cognitively intact healthy older adults. PMID:25463973

  14. Typical cerebral metabolic patterns in various types of dementia: an SPM analysis of 18F-FDG PET images

    Directory of Open Access Journals (Sweden)

    Rui-xue CUI

    2014-04-01

    Full Text Available Objective To delineate the cerebral metabolic patterns presented in 18F-FDG PET images in various types of dementia with SPM analysis.  Methods Patients who underwent 18F-FDG PET scanning with a retrospectively confirmed diagnosis according to strictly defined clinical research criteria were studied. Clinical follow-up enabled appropriate patient inclusion. A total of 62 patients were included, of which 20 patients were diagnosed as Alzheimer's disease (AD, 20 frontotemporal dementia (FTD, 10 dementia with Lewy body (DLB, 7 progressive supranuclear palsy (PSP, 3 primary progressive aphasia (PPA, 1 corticobasal ganglionic degeneration (CBD, 1 multiple system atrophy (MSA. 18F-FDG PET images of each group were analyzed and compared to 20 healthy controls using SPM5. Results Disease-specific patterns of relatively decreased metabolic activity were found in AD (bilateral parietotemporal regions and frontal regions sparing sensorimotor cortex, FTD (asymmetric frontotemporal regions, DLB (occipital lobe, visual cortex and bilateral superior temporal gyrus, PSP (bilateral dorsolateral prefrontal cortex, anterolateral temporal regions, caudate nucleus and mesencephalon, PPA (Broca's area in left frontal lobe, left temporal cortex excepting posterior superior temporal gyrus, CBD (asymmetricly involved cortical regions, prodominately on right side, around bilateral central sulcus and right basal ganglia, MSA (bilateral cerebellum dorsolateral cortex and left putamen, and right medial temporal cortex.  Conclusions Specific dementia related cerebral metabolic patterns in 18F-FDG PET might assist in early differential diagnosis of neurodegenerative diseases. doi: 10.3969/j.issn.1672-6731.2014.04.008

  15. Forest clearfelling effects on dissolved oxygen and metabolism in peatland streams.

    Science.gov (United States)

    O'Driscoll, Connie; O'Connor, Mark; Asam, Zaki-Ul-Zaman; de Eyto, Elvira; Brown, Lee E; Xiao, Liwen

    2016-01-15

    Peatlands cover ∼3% of the world's landmass and large expanses have been altered significantly as a consequence of land use change. Forestry activities are a key pressure on these catchments increasing suspended sediment and nutrient export to receiving waters. The aim of this study was to investigate stream dissolved oxygen (DO) and metabolic activity response following clearfelling of a 39-year-old lodgepole pine and Sitka spruce forestry in an upland peat catchment. Significant effects of clearfelling on water temperature, flows, DO and stream metabolic (photosynthesis, respiration) rates were revealed. Stream temperature and discharge significantly increased in the study stream following clearfelling. Instream ecosystem respiration increased significantly following clearfelling, indicating an increase in the net consumption of organic carbon.

  16. A Mathematical Model of Metabolism and Regulation Provides a Systems-Level View of How Escherichia coli Responds to Oxygen

    Directory of Open Access Journals (Sweden)

    Michael eEderer

    2014-03-01

    Full Text Available The efficient redesign of bacteria for biotechnological purposes, such as biofuel production, waste disposal or specific biocatalytic functions, requires a quantitative systems-level understanding of energy supply, carbon and redox metabolism. The measurement of transcript levels, metabolite concentrations and metabolic fluxes per se gives an incomplete picture. An appreciation of the interdependencies between the different measurement values is essential for systems-level understanding. Mathematical modeling has the potential to provide a coherent and quantitative description of the interplay between gene expression, metabolite concentrations and metabolic fluxes. Escherichia coli undergoes major adaptations in central metabolism when the availability of oxygen changes. Thus, an integrated description of the oxygen response provides a benchmark of our understanding of carbon, energy and redox metabolism. We present the first comprehensive model of the central metabolism of E. coli that describes steady-state metabolism at different levels of oxygen availability. Variables of the model are metabolite concentrations, gene expression levels, transcription factor activities, metabolic fluxes and biomass concentration. We analyze the model with respect to the production capabilities of central metabolism of E. coli. In particular, we predict how precursor and biomass concentration are affected by product formation.

  17. Aerobic and anaerobic metabolism in oxygen minimum layer fishes: the role of alcohol dehydrogenase.

    Science.gov (United States)

    Torres, Joseph J; Grigsby, Michelle D; Clarke, M Elizabeth

    2012-06-01

    Zones of minimum oxygen form at intermediate depth in all the world's oceans as a result of global circulation patterns that keep the water at oceanic mid-depths out of contact with the atmosphere for hundreds of years. In areas where primary production is very high, the microbial oxidation of sinking organic matter results in very low oxygen concentrations at mid-depths. Such is the case with the Arabian Sea, with O(2) concentrations reaching zero at 200 m and remaining very low (fishes (primarily lanternfishes: Mytophidae) inhabiting the Arabian Sea and California borderland perform a daily vertical migration into the low-oxygen layer, spending daylight hours in the oxygen minimum zone and migrating upward into normoxic waters at night. To find out how fishes were able to survive their daily sojourns into the minimum zone, we tested the activity of four enzymes, one (lactate dehydrogenase, LDH) that served as a proxy for anaerobic glycolysis with a conventional lactate endpoint, a second (citrate synthase, CS) that is indicative of aerobic metabolism, a third (malate dehydrogenase) that functions in the Krebs' cycle and as a bridge linking mitochondrion and cytosol, and a fourth (alcohol dehydrogenase, ADH) that catalyzes the final reaction in a pathway where pyruvate is reduced to ethanol. Ethanol is a metabolic product easily excreted by fish, preventing lactate accumulation. The ADH pathway is rarely very active in vertebrate muscle; activity has previously been seen only in goldfish and other cyprinids capable of prolonged anaerobiosis. Activity of the enzyme suite in Arabian Sea and California fishes was compared with that of ecological analogs in the same family and with the same lifestyle but living in systems with much higher oxygen concentrations: the Gulf of Mexico and the Southern Ocean. ADH activities in the Arabian Sea fishes were similar to those of goldfish, far higher than those of confamilials from the less severe minimum in the Gulf of Mexico

  18. 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.

  19. Effects of Hyperbaric Oxygen on Metabolic Capacity of the Skeletal Muscle in Type 2 Diabetic Rats with Obesity

    Directory of Open Access Journals (Sweden)

    Naoto Fujita

    2012-01-01

    Full Text Available We investigated whether hyperbaric oxygen enhances the oxidative metabolic capacity of the skeletal muscle and attenuates adipocyte hypertrophy in type 2 diabetic rats with obesity. Five-week-old male Otsuka Long-Evans Tokushima fatty (OLETF and Long-Evans Tokushima Otsuka (LETO rats were used as diabetic animals and nondiabetic controls, respectively, and assigned to control and hyperbaric oxygen groups. Animals in the hyperbaric oxygen group were exposed to an atmospheric pressure of 1.25 with an oxygen concentration of 36% for 3 h daily. The glucose level at 27 weeks of age was significantly higher in OLETF rats than in LETO rats, but the elevation was inhibited in OLETF rats exposed to hyperbaric oxygen. The slow-to-fast fiber transition in the skeletal muscle was observed in OLETF rats, but the shift was inhibited in OLETF rats exposed to hyperbaric oxygen. Additionally, the oxidative enzyme activity of muscle fibers was increased by hyperbaric oxygen. The adipocyte size was larger in OLETF rats than in LETO rats, but hypertrophied adipocytes were not observed in OLETF rats exposed to hyperbaric oxygen. Hyperbaric oxygen enhances glucose and lipid metabolism in the skeletal muscle, indicating that hyperbaric oxygen can prevent elevation of glucose and adipocyte hypertrophy in diabetic rats with obesity.

  20. Gadd45b prevents autophagy and apoptosis against rat cerebral neuron oxygen-glucose deprivation/reperfusion injury.

    Science.gov (United States)

    He, Guoqian; Xu, Wenming; Tong, Linyan; Li, Shuaishuai; Su, Shiceng; Tan, Xiaodan; Li, Changqing

    2016-04-01

    Autophagic (type II) cell death has been suggested to play pathogenetic roles in cerebral ischemia. Growth arrest and DNA damage response 45b (Gadd45b) has been shown to protect against rat brain ischemia injury through inhibiting apoptosis. However, the relationship between Gadd45b and autophagy in cerebral ischemia/reperfusion (I/R) injury remains uncertain. The aim of this study is to investigate the effect of Gadd45b on autophagy. We adopt the oxygen-glucose deprivation and reperfusion (OGD/R) model of rat primary cortex neurons, and lentivirus interference used to silence Gadd45b expression. Cell viability and injury assay were performed using CCK-8 and LDH kit. Autophagy activation was monitored by expression of ATG5, LC3, Beclin-1, ATG7 and ATG3. Neuron apoptosis was monitored by expression of Bcl-2, Bax, cleaved caspase3, p53 and TUNEL assay. Neuron neurites were assayed by double immunofluorescent labeling with Tuj1 and LC3B. Here, we demonstrated that the expression of Gadd45b was strongly up-regulated at 24 h after 3 h OGD treatment. ShRNA-Gadd45b increased the expression of autophagy related proteins, aggravated OGD/R-induced neuron cell apoptosis and neurites injury. ShRNA-Gadd45b co-treatment with autophagy inhibitor 3-methyladenine (3-MA) or Wortmannin partly inhibited the ratio of LC3II/LC3I, and slightly ameliorated neuron cell apoptosis under OGD/R. Furthermore, shRNA-Gadd45b inhibited the p-p38 level involved in autophagy, but increased the p-JNK level involved in apoptosis. ShRNA-Gadd45b co-treatment with p38 inhibitor obviously induced autophagy. ShRNA-Gadd45b co-treatment with JNK inhibitor alleviated neuron cell apoptosis. In conclusion, our data suggested that Gadd45b inhibited autophagy and apoptosis under OGD/R. Gadd45b may be a common regulatory protein to control autophagy and apoptosis.

  1. Advanced cerebral monitoring in neurocritical care

    Directory of Open Access Journals (Sweden)

    Barazangi Nobl

    2008-01-01

    Full Text Available New cerebral monitoring techniques allow direct measurement of brain oxygenation and metabolism. Investigation using these new tools has provided additional insight into the understanding of the pathophysiology of acute brain injury and suggested new ways to guide management of secondary brain injury. Studies of focal brain tissue oxygen monitoring have suggested ischemic thresholds in focal regions of brain injury and demonstrated the interrelationship between brain tissue oxygen tension (P bt O 2 and other cerebral physiologic and metabolic parameters. Jugular venous oxygen saturation (SjVO 2 monitoring may evaluate global brain oxygen delivery and consumption, providing thresholds for detecting brain hypoperfusion and hyperperfusion. Furthermore, critically low values of P bt O 2 and SjVO 2 have also been predictive of mortality and worsened functional outcome, especially after head trauma. Cerebral microdialysis measures the concentrations of extracellular metabolites which may be relevant to cerebral metabolism or ischemia in focal areas of injury. Cerebral blood flow may be measured in the neurointensive care unit using continuous methods such as thermal diffusion and laser Doppler flowmetry. Initial studies have also attempted to correlate findings from advanced neuromonitoring with neuroimaging using dynamic perfusion computed tomography, positron emission tomography, and Xenon computed tomography. Additionally, new methods of data acquisition, storage, and analysis are being developed to address the increasing burden of patient data from neuromonitoring. Advanced informatics techniques such as hierarchical data clustering, generalized linear models, and heat map dendrograms are now being applied to multivariable patient data in order to better develop physiologic patient profiles to improve diagnosis and treatment.

  2. Interregional cerebral metabolic associativity during a continuous performance task (Part II) : differential alterations in bipolar and unipolar disorders.

    Science.gov (United States)

    Benson, Brenda E; Willis, Mark W; Ketter, Terence A; Speer, Andrew; Kimbrell, Tim A; George, Mark S; Herscovitch, Peter; Post, Robert M

    2008-10-30

    Unipolar and bipolar disorders have often been reported to exhibit abnormal regional brain activity in prefrontal cortex and paralimbic structures compared with healthy controls. We sought to ascertain how regions postulated to be abnormal in bipolar and unipolar disorders were functionally connected to the rest of the brain, and how this associativity differed from healthy controls. Thirty patients with bipolar disorder (BPs), 34 patients with unipolar disorder (UPs), and 66 healthy volunteers (Willis, M.W., Benson, B.E., Ketter, T.A., Kimbrell, T.A., George, M.S., Speer, A.M., Herscovitch, P., Post, R.M., 2008. Interregional cerebral metabolic associativity during a continuous performance task in healthy adults. Psychiatry Research: Neuroimaging 164 (1)) were imaged using F-18-fluorodeoxyglucose and positron emission tomography (FDG-PET) while performing an auditory continuous performance task (CPT). Five bilateral regions of interest (ROIs), namely dorsolateral prefrontal cortex (DLPFC), insula, inferior parietal cortex (INFP), thalamus and cerebellum, were correlated with normalized cerebral metabolism in the rest of the brain while covarying out Hamilton Depression Rating Scale Scores. In bipolar patients compared with controls, metabolism in the left DLPFC and INFP, and bilateral thalamus and insula had more positive and fewer negative metabolic correlations with other brain regions. In contrast, compared with controls, unipolar patients had fewer significant correlative relationships, either positive or negative. In common, bipolar and unipolar patients lacked the normal inverse relationships between the DLPFC and cerebellum, as well as relationships between the primary ROIs and other limbic regions (medial prefrontal cortex, anterior cingulate, and temporal lobes) compared with controls. Associations of DLPFC and INFP with other brain areas were different in each hemisphere in patients and controls. Bipolar patients exhibited exaggerated positive coherence

  3. Response of Nitrate Metabolism in Seedlings of Oilseed Rape (Brassica napus L.) to Low Oxygen Stress

    Institute of Scientific and Technical Information of China (English)

    YU Chang-bing; XIE Yu-yun; HOU Jia-jia; FU You-qiang; SHEN Hong; LIAO Xing

    2014-01-01

    In order to understand the response of nitrate metabolism in seedlings of oilseed rape (Brassica napus L.) to low oxygen stress (LOS), two cultivars were studied at different light, LOS time and exogenous nitrate concentrations under hydroponic stress. Results show that N-uptake and dry matter of rape seedlings were decreased after LOS stress while nitrate accumulation (NA) under LOS was induced by darkness. Nitrate accumulation peaked at 3 d while root activity (RA, deifned as dehydrogenase activity) decreased with prolonged waterlogging exposure. Exogenous nitrate signiifcantly elevated NA and RA. Tungstate (TS) and LOS inhibited nitrate reductase (NR) activity while NR transcription and activity were enhanced by exogenous nitrate. Low oxygen stress stimulated the activity of superoxide dismutase (SOD) and peroxidase (POD) slightly, but inhibited that of catalase (CAT). B. napus L. Zhongshuang 10 (ZS10), a LOS tolerant cultivar, displayed smaller decrease upon dry matter under LOS, higher NA in darkness and lower NA in light than B. napus L. Ganlan CC (GAC), a LOS sensitive variety. ZS10 had lower NA and higher RA after waterlogging and exogenous nitrate treatment, and higher NR activity under TS inhibition than GAC, but the activity of antioxidant enzymes did not change under LOS. The results indicate that nitrate metabolism involved tolerance of rape seedlings to LOS, with lower accumulation and higher reduction of nitrate being related to higher LOS tolerance of rape seedlings exposed to waterlogging.

  4. Myocardial Reloading after Extracorporeal Membrane Oxygenation Alters Substrate Metabolism While Promoting Protein Synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Kajimoto, Masaki; Priddy, Colleen M.; Ledee, Dolena; Xu, Chun; Isern, Nancy G.; Olson, Aaron; Des Rosiers, Christine; Portman, Michael A.

    2013-08-19

    Extracorporeal membrane oxygenation (ECMO) unloads the heart providing a bridge to recovery in children after myocardial stunning. Mortality after ECMO remains high.Cardiac substrate and amino acid requirements upon weaning are unknown and may impact recovery. We assessed the hypothesis that ventricular reloading modulates both substrate entry into the citric acid cycle (CAC) and myocardial protein synthesis. Fourteen immature piglets (7.8-15.6 kg) were separated into 2 groups based on ventricular loading status: 8 hour-ECMO (UNLOAD) and post-wean from ECMO (RELOAD). We infused [2-13C]-pyruvate as an oxidative substrate and [13C6]-L-leucine, as a tracer of amino acid oxidation and protein synthesis into the coronary artery. RELOAD showed marked elevations in myocardial oxygen consumption above baseline and UNLOAD. Pyruvate uptake was markedly increased though RELOAD decreased pyruvate contribution to oxidative CAC metabolism.RELOAD also increased absolute concentrations of all CAC intermediates, while maintaining or increasing 13C-molar percent enrichment. RELOAD also significantly increased cardiac fractional protein synthesis rates by >70% over UNLOAD. Conclusions: RELOAD produced high energy metabolic requirement and rebound protein synthesis. Relative pyruvate decarboxylation decreased with RELOAD while promoting anaplerotic pyruvate carboxylation and amino acid incorporation into protein rather than to the CAC for oxidation. These perturbations may serve as therapeutic targets to improve contractile function after ECMO.

  5. Influence of oxygen tension of the metabolism of vascular smooth muscle: demonstration of a Pasteur effect.

    Science.gov (United States)

    Arnqvist, H J; Lundholm, L

    1976-01-01

    The influence of variations of oxygen tension on the metabolism of bovine mesenteric arteries was studied in vitro. Glucose uptake, lactate production, glycogen content, adenosine triphosphate (ATP), creatine phosphate (CrP) and incorporation of [14C]leucine into protein were determined. The mesenteric arteries were suspended in Krebs-Henseleit bicarbonate buffer which was aerated with a gas mixture containing 5% CO2,O-95% O2 and N2 to 100%. Reduction of the O2 concentration of the gas phase from 95-20% resulted in little metabolic change. A further reduction from 20-0% O2 increased the lactate production 4-fold, indicating a marked Pasteur effect. At 0% O2 the glucose uptake was moderately increased and the glycogen content was decreased. The tissue level of CrP was reduced at a low oxygen tension and at 0% O2 the ATP content was also lowered. The incorporation of leucine into proteins was reduced at 0% O2.

  6. Impact of hypothalamic reactive oxygen species in the control of energy metabolism and food intake

    Directory of Open Access Journals (Sweden)

    Anne eDrougard

    2015-02-01

    Full Text Available Hypothalamus is a key area involved in the control of metabolism and food intake via the integrations of numerous signals (hormones, neurotransmitters, metabolites from various origins. These factors modify hypothalamic neurons activity and generate adequate molecular and behavioral responses to control energy balance. In this complex integrative system, a new concept has been developed in recent years, that includes reactive oxygen species (ROS as a critical player in energy balance. ROS are known to act in many signaling pathways in different peripheral organs, but also in hypothalamus where they regulate food intake and metabolism by acting on different types of neurons, including proopiomelanocortin (POMC and agouti-related protein (AgRP/neuropeptide Y (NPY neurons. Hypothalamic ROS release is under the influence of different factors such as pancreatic and gut hormones, adipokines (leptin, apelin,..., neurotransmitters and nutrients (glucose, lipids,.... The sources of ROS production are multiple including NADPH oxidase, but also the mitochondria which is considered as the main ROS producer in the brain. ROS are considered as signaling molecules, but conversely impairment of this neuronal signaling ROS pathway contributes to alterations of autonomic nervous system and neuroendocrine function, leading to metabolic diseases such as obesity and type 2 diabetes.In this review we focus our attention on factors that are able to modulate hypothalamic ROS release in order to control food intake and energy metabolism, and whose deregulations could participate to the development of pathological conditions. This novel insight reveals an original mechanism in the hypothalamus that controls energy balance and identify hypothalamic ROS signaling as a potential therapeutic strategy to treat metabolic disorders.

  7. Effects of ganglioside GM1 on reduction of brain edema and amelioration of cerebral metabolism after traumatic brain injury

    Institute of Scientific and Technical Information of China (English)

    陈志刚; 卢亦成; 朱诚; 张光霁; 丁学华; 江基尧

    2003-01-01

    Objective: To observe the effects of ganglioside GM1 on reduction of brain edema and amelioration of cerebral metabolism after traumatic brain injury (TBI).Methods: An acute experimental closed TBI model in rats was induced by a fluid-percussion brain injury model. At five and sixty minutes after TBI, the animals were intraperitoneally injected by ganglioside GM1 (30 mg/kg) or the same volume of saline. At the 6th hour after TBI, effects of ganglioside GM1 or saline on changes of mean arterial pressure (MAP), contents of water, lactic acid (LA) and lipid peroxidation (LPO) in the injured cerebral tissues were observed.Results: After TBI, MAP decreased and contents of water, LA and LPO increased in brain injury group; however, MAP was back to normal levels and contents of water, LA and LPO decreased in ganglioside GM1 treated group, compared with those in brain injury group (P0.05) was observed.Conclusions: Ganglioside GM1 does have obvious neuroprotective effect on early TBI.

  8. Influence of apolipoprotein E and its receptors on cerebral amyloid precursor protein metabolism following traumatic brain injury

    Institute of Scientific and Technical Information of China (English)

    ZHOU Shuai; SUN Xiao-chuan

    2012-01-01

    Traumatic brain injury (TBI) is the leading cause of mortality and disability among young individuals in our society,and globally the incidence of TBI is rising sharply.Mounting evidence has indicated that apolipoprotein E (apoE:protein; APOE:gene) genotype influences the outcome after TBI.The proposed mechanism by which APOE affects the clinicopathological consequences of TBI is multifactorial and includes amyloid deposition,disruption of lipid distribution,dysfunction of mitochondrial energy production,oxidative stress and increases intracellular calcium in response to injury.This paper reviews the current state of knowledge regarding the influence of apoE and its receptors on cerebral amyloid betaprotein precursor metabolism following TBI.

  9. Integrating the pulse of the riverscape and landscape: modelling stream metabolism using continuous dissolved oxygen measurements

    Science.gov (United States)

    Soulsby, C.; Birkel, C.; Malcolm, I.; Tetzlaff, D.

    2013-12-01

    Stream metabolism is a fundamental pulse of the watershed which reflects both the in-stream environment and its connectivity with the wider landscape. We used high quality, continuous (15 minute), long-term (>3 years) measurement of stream dissolved oxygen (DO) concentrations to estimate photosynthetic productivity (P) and system respiration (R) in forest and moorland reaches of an upland stream with peaty soils. We calibrated a simple five parameter numerical oxygen mass balance model driven by radiation, stream and air temperature, stream depth and re-aeration capacity. This used continuous 24-hour periods for the whole time series to identify behavioural simulations where DO simulations were re-produced sufficiently well to be considered reasonable representations of ecosystem functioning. Results were evaluated using a seasonal Regional Sensitivity Analysis and a co-linearity index for parameter sensitivity. This showed that >95 % of the behavioural models for the moorland and forest sites were identifiable and able to infer in-stream processes from the DO time series for almost half of all measured days at both sites. Days when the model failed to simulate DO levels successfully provided invaluable insight into time periods when other factors are likely to disrupt in-stream metabolic processes; these include (a) flood events when scour reduces the biomass of benthic primary producers, (b) periods of high water colour in higher summer/autumn flows and (c) low flow periods when hyporheic respiration is evident. Monthly P/R ratios tree cover is likely to be a much larger source of carbon to the atmosphere (122 mmol C m-2 d-1) compared to the forested reach (64 mmol C m-2 d-1). The study indicates the value of integrating field and modelling studies of stream metabolism as a means of understanding the dynamic interactions of the riverscape and its surrounding landscape.

  10. Stress-related changes in cerebral catecholamine and indoleamine metabolism: lack of effect of adrenalectomy and corticosterone.

    Science.gov (United States)

    Dunn, A J

    1988-08-01

    The concentrations of catecholamine and indoleamine metabolites were measured in intact and adrenalectomized mice to determine whether adrenal hormones mediate or modulate the stress-induced responses. Thirty minutes of footshock resulted in significant increases of the ratios of the dopamine (DA) catabolite, dihydroxyphenylacetic acid (DOPAC), to DA in prefrontal cortex, nucleus accumbens, striatum, hypothalamus, and brainstem, and of homovanillic (HVA)/DA ratios in nucleus accumbens, striatum, amygdala, and hypothalamus. Ratios of 3-methoxy-4-hydroxyphenylethyleneglycol to norepinephrine (NE) were also increased in prefrontal cortex, nucleus accumbens, septum, amygdala, hypothalamus, hippocampus, and brainstem. The concentration of NE was decreased in amygdala. 5-Hydroxyindoleacetic acid (5-HIAA)/5-hydroxytryptamine (5-HT, serotonin) ratios and free tryptophan were also increased in every brain region. Very similar data were obtained from mice restrained for 30 min. Adrenalectomy resulted in increased HVA/DA ratios in prefrontal cortex and striatum, and 5-HIAA/5-HT in septum. The stress-related changes were largely similar in adrenalectomized mice. Significant interactions between adrenalectomy and footshock treatment occurred in prefrontal cortical DOPAC/DA and hypothalamic NE which was depleted only in adrenalectomized mice, suggesting tendencies for these measures to be more responsive in adrenalectomized mice. Corticosterone administration (0.5-2.0 mg/kg s.c.) which resulted in plasma concentrations in the physiological range did not alter the concentrations of the cerebral metabolites measured in any region. We conclude that adrenal hormones do not mediate cerebral catecholamine or indoleamine metabolism in stress, although adrenalectomy may affect HVA and 5-HIAA metabolism, and there was a tendency for catecholamines to be more sensitive to stress in adrenalectomized animals.

  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. Arterial spin labeling perfusion MRI in cerebral ischaemia

    NARCIS (Netherlands)

    Bokkers, R.P.H.

    2011-01-01

    Cerebral perfusion is the basis for the delivery of oxygen and nutrients to the brain. Brain tissue can become damaged when there is a shortage in the blood supply. Basic physiological functions such as synaptic transmission, the membrane ion pump and energy metabolism are disrupted and within minut

  13. Sub-sets of cancer stem cells differ intrinsically in their patterns of oxygen metabolism.

    Directory of Open Access Journals (Sweden)

    Luke Gammon

    Full Text Available The glycolytic response of hypoxic cells is primarily mediated by the hypoxia inducible factor alpha (HIF-1α but even in the presence of abundant oxygen tumours typically show high rates of glycolysis. Higher levels of HIF-1α in tumours are associated with a poorer prognosis and up-regulation of markers of epithelial mesenchymal transition (EMT due to HIF-1α actions. We have recently shown that EMT occurs within the CD44(high cancer stem cell (CSC fraction and that epithelial and EMT CSCs are distinguished by high and low ESA expression, respectively. We here show that hypoxia induces a marked shift of the CSC fraction towards EMT leading to altered cell morphology, an increased proportion of CD44(high/ESA(low cells, patterns of gene expression typical of EMT, and enhanced sphere-forming ability. The size of EMT fractions returned to control levels in normoxia indicating a reversible process. Surprisingly, however, even under normoxic conditions a fraction of EMT CSCs was present and maintained high levels of HIF-1α, apparently due to actions of cytokines such as TNFα. Functionally, this EMT CSC fraction showed decreased mitochondrial mass and membrane potential, consumed far less oxygen per cell, and produced markedly reduced levels of reactive oxygen species (ROS. These differences in the patterns of oxygen metabolism of sub-fractions of tumour cells provide an explanation for the general therapeutic resistance of CSCs and for the even greater resistance of EMT CSCs. They also identify potential mechanisms for manipulation of CSCs.

  14. Effects of oxygen and glucose deprivation on the expression and distribution of neuronal and inducible nitric oxide synthases and on protein nitration in rat cerebral cortex.

    Science.gov (United States)

    Alonso, David; Serrano, Julia; Rodríguez, Ignacio; Ruíz-Cabello, Jesús; Fernández, Ana Patricia; Encinas, Juan Manuel; Castro-Blanco, Susana; Bentura, María Luisa; Santacana, María; Richart, Ana; Fernández-Vizarra, Paula; Uttenthal, Lars Otto; Rodrigo, José

    2002-02-04

    Changes in the nitric oxide (NO) system of the rat cerebral cortex were investigated by immunohistochemistry, immunoblotting, NO synthase (NOS) activity assay, and magnetic resonance imaging (MRI) in an experimental model of global cerebral ischemia and reperfusion. Brains were perfused transcardially with an oxygenated plasma substitute and subjected to 30 minutes of oxygen and glucose deprivation, followed by reperfusion for up to 12 hours with oxygenated medium containing glucose. A sham group was perfused without oxygen or glucose deprivation, and a further group was treated with the NOS inhibitor N(omega)-nitro-L-arginine methyl ester (L-NAME) before and during perfusion. Global ischemia led to cerebrocortical injury as shown by diffusion MRI. This was accompanied by increasing morphologic changes in the large type I interneurons expressing neuronal NOS (nNOS) and the appearance of nNOS immunoreactivity in small type II neurons. The nNOS-immunoreactive band and calcium-dependent NOS activity showed an initial increase, followed by a fall after 6 hours of reperfusion. Inducible NOS immunoreactivity appeared in neurons, especially pyramidal cells of layers IV-V, after 4 hours of reperfusion, with corresponding changes on immunoblotting and in calcium-independent NOS activity. Immunoreactive protein nitrotyrosine, present in the nuclear area of neurons in nonperfused controls and sham-perfused animals, showed changes in intensity and distribution, appearing in the neuronal processes during the reperfusion period. Prior and concurrent L-NAME administration blocked the changes on diffusion MRI and attenuated the morphologic changes, suggesting that NO and consequent peroxynitrite formation during ischemia-reperfusion contributes to cerebral injury.

  15. Decreased regional cerebral glucose metabolism in the prefrontal regions in adults' with internet game addiction

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hyun Soo; Bang, Soong Ae; Yoon, Eun Jin; Cho, Sang Soo; Kim, Sang Hee; Kim, Yu Kyeong; Kim, Sang Eun [Seoul National Univ. College of Medicine, Seoul (Korea, Republic of)

    2007-07-01

    Internet Game Addiction (IGA) is known to be associated with poor decision-making and diminished impulse control; however, the underlying neural substrates of IGA have not been identified. To investigate the neural substrates of IGA, we compared regional cerebral glucose metabolism between adults with and without IGA, primarily in the prefrontal brain regions, which have been implicated in inhibitory control. We studied 10 right-handed participants (5 controls: male, 23.8{+-}0.75 y, 5 IGAs: male, 22.6{+-}2.42 y) with FDG PET. A standardized questionnaire was used to assess the severity of IGA. Before scanning, all subjects carried out a computerized version of the Iowa Gambling Task (IGT) and the Balloon Analogue Risk Task (BART), as measures of behavioral inhibitory control. Statistical Parametric Mapping 2 (SPM2) was used to analyze differences in regional brain glucose metabolism between adults with and without IGA. Consistent with our predictions, compared to controls, significant reductions in FDG uptake in individuals with IGA were found in the bilateral orbitofrontal gyrus (BA 11, 47), bilateral inferior frontal gyrus (BA 44, 48), cingulate cortex (BA 24), and bilateral supplementary motor area (SMA) (BA 6); whereas increases were found in the bilateral hippocampus. Correlation analyses within the IGA group further showed that the level of glucose metabolism in the right orbitofrontal gyrus was marginally positively correlated with task scores in BART. Our results showed that IGA is associated with reduced glucose metabolism in the prefrontal regions involved in inhibitory control. This finding highlights dysfunctional inhibitory brain systems in individuals with IGA and offers implications for the development for therapeutic paradigms for IGA.

  16. 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 transient global cerebral ischemia in gerbils. For in vitro studies, hippocampal slice cultures derived from 7-day-old mice and grown for 14 days, were submersed in oxygen-glucose deprived medium for 30 min and exposed to PNQX for 24 h, starting together with OGD, immediately after OGD, or 2 h after OGD...... ischemia in gerbils in vivo and oxygen-glucose deprivation in mouse hippocampal slice cultures....

  17. Hypothalamic sensing of ketone bodies after prolonged cerebral exposure leads to metabolic control dysregulation

    Science.gov (United States)

    Carneiro, Lionel; Geller, Sarah; Hébert, Audrey; Repond, Cendrine; Fioramonti, Xavier; Leloup, Corinne; Pellerin, Luc

    2016-01-01

    Ketone bodies have been shown to transiently stimulate food intake and modify energy homeostasis regulatory systems following cerebral infusion for a moderate period of time (neuropeptides. Moreover, insulinemia was increased and caused a decrease in glucose production despite an increased resistance to insulin. The present study confirms that ketone bodies reaching the brain stimulates food intake. Moreover, we provide evidence that a prolonged hyperketonemia leads to a dysregulation of energy homeostasis control mechanisms. Finally, this study shows that brain exposure to ketone bodies alters insulin signaling and consequently glucose homeostasis. PMID:27708432

  18. Multichannel near infrared spectroscopy indicates regional variations in cerebral autoregulation in infants supported on extracorporeal membrane oxygenation

    Science.gov (United States)

    Papademetriou, Maria D.; Tachtsidis, Ilias; Elliot, Martin J.; Hoskote, Aparna; Elwell, Clare E.

    2012-06-01

    Assessing noninvasively cerebral autoregulation, the protective mechanism of the brain to maintain constant cerebral blood flow despite changes in blood pressure, is challenging. Infants on life support system (ECMO) for cardiorespiratory failure are at risk of cerebral autoregulation impairment and consequent neurological problems. We measured oxyhaemoglobin concentration (HbO2) by multichannel (12 channels) near-infrared spectroscopy (NIRS) in six infants during sequential changes in ECMO flow. Wavelet cross-correlation (WCC) between mean arterial pressure (MAP) and HbO2 was used to construct a time-frequency representation of the concordance between the two signals to assess the nonstationary aspect of cerebral autoregulation and investigate regional variations. Group data showed that WCC increases with decreasing ECMO flow indicating higher concordance between MAP and HbO2 and demonstrating loss of cerebral autoregulation at low ECMO flows. Statistically significant differences in WCC were observed between channels placed on the right and left scalp with channels on the right exhibiting higher values of WCC suggesting that the right hemisphere was more susceptible to disruption of cerebral autoregulation. Multichannel NIRS in conjunction with wavelet analysis methods can be used to assess regional variations in dynamic cerebral autoregulation with important clinical application in the management of critically ill children on life support systems.

  19. Age- and Sex-Associated Changes in Cerebral Glucose Metabolism in Normal Healthy Subjects: Statistical Parametric Mapping Analysis of F-18 Fluorodeoxyglucose Brain Positron Emission Tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kim, In-Ju; Kim, Seong-Jang; Kim, Yong-Ki (Dept. of Nuclear Medicine, Pusan National Univ. Hospital, Busan (Korea); Medical Research Institute, Pusan National Univ., Busan (Korea)). e-mail: growthkim@daum.net/growthkim@pusan.ac.kr)

    2009-12-15

    Background: The age- and sex-associated changes of brain development are unclear and controversial. Several previous studies showed conflicting results of a specific pattern of cerebral glucose metabolism or no differences of cerebral glucose metabolism in association with normal aging process and sex. Purpose: To investigate the effects of age and sex on changes in cerebral glucose metabolism in healthy subjects using fluorine-18 fluorodeoxyglucose (F-18 FDG) brain positron emission tomography (PET) and statistical parametric mapping (SPM) analysis. Material and Methods: Seventy-eight healthy subjects (32 males, mean age 46.6+-18.2 years; 46 females, mean age 40.6+-19.8 years) underwent F-18 FDG brain PET. Using SPM, age- and sex-associated changes in cerebral glucose metabolism were investigated. Results: In males, a negative correlation existed in several gray matter areas, including the right temporopolar (Brodmann area [BA] 38), right orbitofrontal (BA 47), left orbitofrontal gyrus (BA 10), left dorsolateral frontal gyrus (BA 8), and left insula (BA 13) areas. A positive relationship existed in the left claustrum and left thalamus. In females, negative changes existed in the left caudate body, left temporopolar area (BA 38), right orbitofrontal gyri (BA 47 and BA 10), and right dorsolateral prefrontal cortex (BA 46). A positive association was demonstrated in the left subthalamic nucleus and the left superior frontal gyrus. In white matter, an age-associated decrease in FDG uptake in males was shown in the left insula, and increased FDG uptake was found in the left corpus callosum. The female group had an age-associated negative correlation of FDG uptake only in the right corpus callosum. Conclusion: Using SPM, we found not only similar areas of brain, but also sex-specific cerebral areas of age-associated changes of FDG uptake

  20. Partitioning the metabolic scope: the importance of anaerobic metabolism and implications for the oxygen- and capacity-limited thermal tolerance (OCLTT) hypothesis

    DEFF Research Database (Denmark)

    Ejbye-Ernst, Rasmus; Tirsgaard, B.; Michaelsen, Thomas Y.;

    2016-01-01

    Ongoing climate change is predicted to affect the distribution and abundance of aquatic ectotherms owing to increasing constraints on organismal physiology, in particular involving the metabolic scope (MS) available for performance and fitness. The oxygen- and capacity-limited thermal tolerance...

  1. 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

  2. Hypoxia Tolerance and Metabolic Suppression in Oxygen Minimum Zone Euphausiids: Implications for Ocean Deoxygenation and Biogeochemical Cycles.

    Science.gov (United States)

    Seibel, Brad A; Schneider, Jillian L; Kaartvedt, Stein; Wishner, Karen F; Daly, Kendra L

    2016-10-01

    The effects of regional variations in oxygen and temperature levels with depth were assessed for the metabolism and hypoxia tolerance of dominant euphausiid species. The physiological strategies employed by these species facilitate prediction of changing vertical distributions with expanding oxygen minimum zones and inform estimates of the contribution of vertically migrating species to biogeochemical cycles. The migrating species from the Eastern Tropical Pacific (ETP), Euphausia eximia and Nematoscelis gracilis, tolerate a Partial Pressure (PO2) of 0.8 kPa at 10 °C (∼15 µM O2) for at least 12 h without mortality, while the California Current species, Nematoscelis difficilis, is incapable of surviving even 2.4 kPa PO2 (∼32 µM O2) for more than 3 h at that temperature. Euphausia diomedeae from the Red Sea migrates into an intermediate oxygen minimum zone, but one in which the temperature at depth remains near 22 °C. Euphausia diomedeae survived 1.6 kPa PO2 (∼22 µM O2) at 22 °C for the duration of six hour respiration experiments. Critical oxygen partial pressures were estimated for each species, and, for E. eximia, measured via oxygen consumption (2.1 kPa, 10 °C, n = 2) and lactate accumulation (1.1 kPa, 10 °C). A primary mechanism facilitating low oxygen tolerance is an ability to dramatically reduce energy expenditure during daytime forays into low oxygen waters. The ETP and Red Sea species reduced aerobic metabolism by more than 50% during exposure to hypoxia. Anaerobic glycolytic energy production, as indicated by whole-animal lactate accumulation, contributed only modestly to the energy deficit. Thus, the total metabolic rate was suppressed by ∼49-64%. Metabolic suppression during diel migrations to depth reduces the metabolic contribution of these species to vertical carbon and nitrogen flux (i.e., the biological pump) by an equivalent amount. Growing evidence suggests that metabolic suppression is a widespread strategy among migrating

  3. Hypoxia Tolerance and Metabolic Suppression in Oxygen Minimum Zone Euphausiids: Implications for Ocean Deoxygenation and Biogeochemical Cycles

    KAUST Repository

    Seibel, Brad A.

    2016-08-10

    The effects of regional variations in oxygen and temperature levels with depth were assessed for the metabolism and hypoxia tolerance of dominant euphausiid species. The physiological strategies employed by these species facilitate prediction of changing vertical distributions with expanding oxygen minimum zones and inform estimates of the contribution of vertically migrating species to biogeochemical cycles. The migrating species from the Eastern Tropical Pacific (ETP), Euphausia eximia and Nematoscelis gracilis, tolerate a Partial Pressure (PO2) of 0.8 kPa at 10 °C (∼15 µM O2) for at least 12 h without mortality, while the California Current species, Nematoscelis difficilis, is incapable of surviving even 2.4 kPa PO2 (∼32 µM O2) for more than 3 h at that temperature. Euphausia diomedeae from the Red Sea migrates into an intermediate oxygen minimum zone, but one in which the temperature at depth remains near 22 °C. Euphausia diomedeae survived 1.6 kPa PO2 (∼22 µM O2) at 22 °C for the duration of six hour respiration experiments. Critical oxygen partial pressures were estimated for each species, and, for E. eximia, measured via oxygen consumption (2.1 kPa, 10 °C, n = 2) and lactate accumulation (1.1 kPa, 10 °C). A primary mechanism facilitating low oxygen tolerance is an ability to dramatically reduce energy expenditure during daytime forays into low oxygen waters. The ETP and Red Sea species reduced aerobic metabolism by more than 50% during exposure to hypoxia. Anaerobic glycolytic energy production, as indicated by whole-animal lactate accumulation, contributed only modestly to the energy deficit. Thus, the total metabolic rate was suppressed by ∼49–64%. Metabolic suppression during diel migrations to depth reduces the metabolic contribution of these species to vertical carbon and nitrogen flux (i.e., the biological pump) by an equivalent amount. Growing evidence suggests that metabolic suppression is a widespread strategy among migrating

  4. Cerebral metabolic and structural alterations in hereditary spastic paraplegia with thin corpus callosum assessed by MRS and DTI

    Energy Technology Data Exchange (ETDEWEB)

    Dreha-Kulaczewski, Steffi [Georg August University, Department of Pediatrics and Pediatric Neurology, Faculty of Medicine, Goettingen (Germany); Georg August University, MR Research in Neurology and Psychiatry, Goettingen (Germany); Dechent, Peter; Helms, Gunther [Georg August University, MR Research in Neurology and Psychiatry, Goettingen (Germany); Frahm, Jens [Biomedizinische NMR Forschungs GmbH, Max-Planck-Institut fuer Biophysikalische Chemie, Goettingen (Germany); Gaertner, Jutta; Brockmann, Knut [Georg August University, Department of Pediatrics and Pediatric Neurology, Faculty of Medicine, Goettingen (Germany)

    2006-12-15

    Hereditary spastic paraplegia with thin corpus callosum (HSP-TCC) is a complicated form of autosomal-recessive hereditary spastic paraplegia. Characteristic clinical features comprise progressive spastic gait, cognitive impairment, and ataxia. Diagnostic MRI findings include thinning of the corpus callosum and non-progressive white matter (WM) alterations. To study the extent of axonal involvement, we performed localized proton magnetic resonance spectroscopy (MRS) of the cerebral WM and cortical grey matter (GM) in a patient with HSP-TCC at 20 and 25 years of age. The second investigation included diffusion tensor imaging (DTI). While MRS of the GM was normal, affected WM was characterized by major metabolic alterations such as reduced concentrations of N-acetylaspartate and N-acetylaspartyl-glutamate, creatine and phosphocreatine, and choline-containing compounds as well as elevated levels of myo-inositol. These abnormalities showed progression over a period of 5 years. DTI revealed increased mean diffusivity as well as reduced fractional anisotropy in periventricular WM. The metabolic and structural findings are consistent with progressive neuroaxonal loss in the WM accompanied by astrocytic proliferation - histopathological changes known to occur in HSP-TCC. Our results are in agreement with the hypothesis that the primary pathological process in HSP-TCC affects the axon, possibly due to impaired axonal trafficking. (orig.)

  5. Metabolic and neurological patterns in chronic cerebral infarction: a single-voxel {sup 1}H-MR spectroscopy study

    Energy Technology Data Exchange (ETDEWEB)

    Kamada, K. [Department of Neurosurgery, Hokkaido University School of Medicine, North-15, West-7, Kita-Ku, Sapporo 060 (Japan); Houkin, K. [Department of Neurosurgery, Hokkaido University School of Medicine, North-15, West-7, Kita-Ku, Sapporo 060 (Japan); Iwasaki, Y. [Department of Neurosurgery, Hokkaido University School of Medicine, North-15, West-7, Kita-Ku, Sapporo 060 (Japan); Abe, H. [Department of Neurosurgery, Hokkaido University School of Medicine, North-15, West-7, Kita-Ku, Sapporo 060 (Japan); Kashiwaba, T. [Kashiwaba Neurosurgical Hospital, Hokkaido (Japan)

    1997-08-01

    The details of brain metabolism in chronic cerebral infarcts have not been clarified. Using proton MR spectroscopy ({sup 1}H-MRS) at 1.5 T, we measured biochemical changes in 16 patients with large infarcts involving the motor cortex in the chronic phase (median 293.9 days) and related the findings to clinical data. Localised spectra were obtained using point-resolved spectroscopy, with an echo time of 270 ms. Regions of interest were placed on the frontal lobe, including the precentral gyrus and central sulcus. Motor function was assessed by the manual muscle power test at the time of the {sup 1}H-MRS study. Only three patients with severe paresis had no signal in the lesions and a lactate signal was obtained in 13 cases. N -acetyl aspartate (NAA) was observed in 4 cases with recanalisation of an occluded vessel. Motor function correlated strongly with the NAA/choline-containing compounds (Cho) ratio (P < 0.01) and lactate/Cho ratio (P < 0.01). We found various metabolic patterns, reflecting residual neurological function. (orig.). With 4 figs., 2 tabs.

  6. The effect of diazepam sedation on cerebral glucose metabolism in Alzheimer's disease as measured using positron emission tomography.

    Science.gov (United States)

    Foster, N L; VanDerSpek, A F; Aldrich, M S; Berent, S; Hichwa, R H; Sackellares, J C; Gilman, S; Agranoff, B W

    1987-08-01

    The effect of sedation induced by intravenous diazepam on cerebral glucose metabolic activity was examined with [18F]2-fluoro-2-deoxy-D-glucose (FDG) and positron emission tomography (PET) in five patients with probable Alzheimer's disease. Each subject was studied on 2 separate days: on one occasion at rest with eyes patched and ears open, and on the second when sedated with intravenous diazepam titrated to maintain stage II sleep by clinical and EEG criteria. Similar patterns of glucose uptake were observed in both the presence and the absence of sedation, but overall glucose utilization was depressed an average of 20% and was closely correlated with the amount of diazepam administered prior to the injection of FDG. The predominant temporoparietal hypometabolism and relative sparing of frontal metabolism observed in this disease are therefore not explained by differences in anxiety or activity level in this patient group. Utilization of diazepam sedation for PET study appears to be safe and may permit the study of patients otherwise unable to cooperate with FDG-PET procedures.

  7. Partitioning the metabolic scope: the importance of anaerobic metabolism and implications for the oxygen- and capacity-limited thermal tolerance (OCLTT) hypothesis.

    Science.gov (United States)

    Ejbye-Ernst, Rasmus; Michaelsen, Thomas Y; Tirsgaard, Bjørn; Wilson, Jonathan M; Jensen, Lasse F; Steffensen, John F; Pertoldi, Cino; Aarestrup, Kim; Svendsen, Jon C

    2016-01-01

    Ongoing climate change is predicted to affect the distribution and abundance of aquatic ectotherms owing to increasing constraints on organismal physiology, in particular involving the metabolic scope (MS) available for performance and fitness. The oxygen- and capacity-limited thermal tolerance (OCLTT) hypothesis prescribes MS as an overarching benchmark for fitness-related performance and assumes that any anaerobic contribution within the MS is insignificant. The MS is typically derived from respirometry by subtracting standard metabolic rate from the maximal metabolic rate; however, the methodology rarely accounts for anaerobic metabolism within the MS. Using gilthead sea bream (Sparus aurata) and Trinidadian guppy (Poecilia reticulata), this study tested for trade-offs (i) between aerobic and anaerobic components of locomotor performance; and (ii) between the corresponding components of the MS. Data collection involved measuring oxygen consumption rate at increasing swimming speeds, using the gait transition from steady to unsteady (burst-assisted) swimming to detect the onset of anaerobic metabolism. Results provided evidence of the locomotor performance trade-off, but only in S. aurata. In contrast, both species revealed significant negative correlations between aerobic and anaerobic components of the MS, indicating a trade-off where both components of the MS cannot be optimized simultaneously. Importantly, the fraction of the MS influenced by anaerobic metabolism was on average 24.3 and 26.1% in S. aurata and P. reticulata, respectively. These data highlight the importance of taking anaerobic metabolism into account when assessing effects of environmental variation on the MS, because the fraction where anaerobic metabolism occurs is a poor indicator of sustainable aerobic performance. Our results suggest that without accounting for anaerobic metabolism within the MS, studies involving the OCLTT hypothesis could overestimate the metabolic scope available for

  8. Partitioning the metabolic scope: the importance of anaerobic metabolism and implications for the oxygen- and capacity-limited thermal tolerance (OCLTT) hypothesis

    Science.gov (United States)

    Ejbye-Ernst, Rasmus; Michaelsen, Thomas Y.; Tirsgaard, Bjørn; Wilson, Jonathan M.; Jensen, Lasse F.; Steffensen, John F.; Pertoldi, Cino; Aarestrup, Kim; Svendsen, Jon C.

    2016-01-01

    Ongoing climate change is predicted to affect the distribution and abundance of aquatic ectotherms owing to increasing constraints on organismal physiology, in particular involving the metabolic scope (MS) available for performance and fitness. The oxygen- and capacity-limited thermal tolerance (OCLTT) hypothesis prescribes MS as an overarching benchmark for fitness-related performance and assumes that any anaerobic contribution within the MS is insignificant. The MS is typically derived from respirometry by subtracting standard metabolic rate from the maximal metabolic rate; however, the methodology rarely accounts for anaerobic metabolism within the MS. Using gilthead sea bream (Sparus aurata) and Trinidadian guppy (Poecilia reticulata), this study tested for trade-offs (i) between aerobic and anaerobic components of locomotor performance; and (ii) between the corresponding components of the MS. Data collection involved measuring oxygen consumption rate at increasing swimming speeds, using the gait transition from steady to unsteady (burst-assisted) swimming to detect the onset of anaerobic metabolism. Results provided evidence of the locomotor performance trade-off, but only in S. aurata. In contrast, both species revealed significant negative correlations between aerobic and anaerobic components of the MS, indicating a trade-off where both components of the MS cannot be optimized simultaneously. Importantly, the fraction of the MS influenced by anaerobic metabolism was on average 24.3 and 26.1% in S. aurata and P. reticulata, respectively. These data highlight the importance of taking anaerobic metabolism into account when assessing effects of environmental variation on the MS, because the fraction where anaerobic metabolism occurs is a poor indicator of sustainable aerobic performance. Our results suggest that without accounting for anaerobic metabolism within the MS, studies involving the OCLTT hypothesis could overestimate the metabolic scope available for

  9. Evidence of circadian rhythm, oxygen regulation capacity, metabolic repeatability and positive correlations between forced and spontaneous maximal metabolic rates in lake sturgeon Acipenser fulvescens.

    Directory of Open Access Journals (Sweden)

    Jon C Svendsen

    Full Text Available Animal metabolic rate is variable and may be affected by endogenous and exogenous factors, but such relationships remain poorly understood in many primitive fishes, including members of the family Acipenseridae (sturgeons. Using juvenile lake sturgeon (Acipenser fulvescens, the objective of this study was to test four hypotheses: 1 A. fulvescens exhibits a circadian rhythm influencing metabolic rate and behaviour; 2 A. fulvescens has the capacity to regulate metabolic rate when exposed to environmental hypoxia; 3 measurements of forced maximum metabolic rate (MMR(F are repeatable in individual fish; and 4 MMR(F correlates positively with spontaneous maximum metabolic rate (MMR(S. Metabolic rates were measured using intermittent flow respirometry, and a standard chase protocol was employed to elicit MMR(F. Trials lasting 24 h were used to measure standard metabolic rate (SMR and MMR(S. Repeatability and correlations between MMR(F and MMR(S were analyzed using residual body mass corrected values. Results revealed that A. fulvescens exhibit a circadian rhythm in metabolic rate, with metabolism peaking at dawn. SMR was unaffected by hypoxia (30% air saturation (O(2sat, demonstrating oxygen regulation. In contrast, MMR(F was affected by hypoxia and decreased across the range from 100% O(2sat to 70% O(2sat. MMR(F was repeatable in individual fish, and MMR(F correlated positively with MMR(S, but the relationships between MMR(F and MMR(S were only revealed in fish exposed to hypoxia or 24 h constant light (i.e. environmental stressor. Our study provides evidence that the physiology of A. fulvescens is influenced by a circadian rhythm and suggests that A. fulvescens is an oxygen regulator, like most teleost fish. Finally, metabolic repeatability and positive correlations between MMR(F and MMR(S support the conjecture that MMR(F represents a measure of organism performance that could be a target of natural selection.

  10. Medida da diferença artério-venosa de oxigênio na monitorização de pacientes com hemorragia subaracnóidea por aneurisma cerebral Measurement of arteriovenous oxygen difference in the monitoring of patients with subarachnoid haemorrhage due to cerebral aneurysm

    Directory of Open Access Journals (Sweden)

    Ronaldo Sérgio Santana Pereira

    1997-01-01

    Full Text Available A diferença artério-venosa de oxigênio (DAVO2, pelo fato de estar relacionada com o metabolismo cerebral, reflete alterações que ocorrem em determinadas situações patológicas, entre elas as causadas pela hemorragia subaracnóidea espontânea (HSAE. Com a finalidade de avaliar a relação entre alterações na DAVO2 com o quadro clínico e a evolução de pacientes com HSAE, devido à ruptura de aneurisma cerebral, este método foi utilizado em 30 pacientes portadores desta patologia, admitidos na Unidade de Neurocirurgia do HBDF. A HSAE foi confirmada por CT de crânio em 17 pacientes e por punção lombar em 13. Dezoito pacientes foram admitidos com Hunt & Hess (H&H I ou II, sete com H&H III e cinco com H&H IV ou V. A medida da DAVO2 baseou-se na equação de Fick e os resultados clínicos foram avaliados pela escala de seqüelas de Glasgow. Dezenove pacientes apresentaram DAVO2 normais (inicialmente e durante a evolução, sendo que três faleceram; cinco tiveram valores de DAVO2 sempre baixos e três faleceram; os restantes seis pacientes tiveram valores da DAVO2 sempre elevados e dois faleceram. Os pacientes com DAVO2 normais tiveram melhor evolução clínica e índice de mortalidade menor, quando comparados com os pacientes com valores anormais da DAVO2 (pThe arterious venous oxygen difference (AVDO2 due to the close relationship with cerebral metabolic rate of oxygen and cerebral blood flow shows metabolic alterations that occur in some pathological situations in the brain including subarachnoid haemorrhage. The AVDO2 was calculated by the Fick equation and the results evaluated by the Glasgow outcome scale. Measurements of arteriojugular oxygen difference were carried out in 30 patients with subarachnoid haemorrhage due to rupture of intracranial aneurysms, as an attempt to monitor the relationship between changes in AVDO2, clinical picture, and evolution of the patients. The subarachnoid haemorrhage was diagnosed by CT scan in

  11. 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.

  12. Greater left cerebral hemispheric metabolism in bulimia assessed by positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Wu, J.C.; Hagman, J.; Buchsbaum, M.S.; Blinder, B.; Derrfler, M.; Tai, W.Y.; Hazlett, E.; Sicotte, N. (Univ. of California, Irvine (USA))

    1990-03-01

    Eight women with bulimia and eight age- and sex-matched normal control subjects were studied with positron emission tomography using (18F)-fluorodeoxyglucose (FDG) as a tracer of brain metabolic rate. Subjects performed a visual vigilance task during FDG uptake. In control subjects, the metabolic rate was higher in the right hemisphere than in the left, but patients with bulimia did not have this normal asymmetry. Lower metabolic rates in the basal ganglia, found in studies of depressed subjects, and higher rates in the basal ganglia, reported in a study of anorexia nervosa, were not found. This is consistent with the suggestion that bulimia is a diagnostic grouping distinct from these disorders.

  13. Staphylococcus epidermidis: metabolic adaptation and biofilm formation in response to different oxygen concentrations.

    Science.gov (United States)

    Uribe-Alvarez, Cristina; Chiquete-Félix, Natalia; Contreras-Zentella, Martha; Guerrero-Castillo, Sergio; Peña, Antonio; Uribe-Carvajal, Salvador

    2016-02-01

    Staphylococcus epidermidis has become a major health hazard. It is necessary to study its metabolism and hopefully uncover therapeutic targets. Cultivating S. epidermidis at increasing oxygen concentration [O2] enhanced growth, while inhibiting biofilm formation. Respiratory oxidoreductases were differentially expressed, probably to prevent reactive oxygen species formation. Under aerobiosis, S. epidermidis expressed high oxidoreductase activities, including glycerol-3-phosphate dehydrogenase, pyruvate dehydrogenase, ethanol dehydrogenase and succinate dehydrogenase, as well as cytochromes bo and aa3; while little tendency to form biofilms was observed. Under microaerobiosis, pyruvate dehydrogenase and ethanol dehydrogenase decreased while glycerol-3-phosphate dehydrogenase and succinate dehydrogenase nearly disappeared; cytochrome bo was present; anaerobic nitrate reductase activity was observed; biofilm formation increased slightly. Under anaerobiosis, biofilms grew; low ethanol dehydrogenase, pyruvate dehydrogenase and cytochrome bo were still present; nitrate dehydrogenase was the main terminal electron acceptor. KCN inhibited the aerobic respiratory chain and increased biofilm formation. In contrast, methylamine inhibited both nitrate reductase and biofilm formation. The correlation between the expression and/or activity or redox enzymes and biofilm-formation activities suggests that these are possible therapeutic targets to erradicate S. epidermidis.

  14. Human regional cerebral glucose metabolism during non-rapid eye movement sleep in relation to waking.

    Science.gov (United States)

    Nofzinger, Eric A; Buysse, Daniel J; Miewald, Jean M; Meltzer, Carolyn C; Price, Julie C; Sembrat, Robert C; Ombao, Hernando; Reynolds, Charles F; Monk, Timothy H; Hall, Martica; Kupfer, David J; Moore, Robert Y

    2002-05-01

    Sleep is an essential human function. Although the function of sleep has generally been regarded to be restorative, recent data indicate that it also plays an important role in cognition. The neurobiology of human sleep is most effectively analysed with functional imaging, and PET studies have contributed substantially to our understanding of both rapid eye movement (REM) and non-rapid eye movement (NREM) sleep. In this study, PET was used to determine patterns of regional glucose metabolism in NREM sleep compared with waking. We hypothesized that brain structures related to waking cognitive function would show a persistence of function into the NREM sleep state. Fourteen healthy subjects (age range 21-49 years; 10 women, 4 men) underwent concurrent EEG sleep studies and [(18)F]fluoro-2-deoxy-D-glucose PET scans during waking and NREM sleep. Whole-brain glucose metabolism declined significantly from waking to NREM sleep. Relative decreases in regional metabolism from waking to NREM sleep occurred in wide areas of frontal, parietal, temporal and occipital association cortex, primary visual cortex, and in anterior/dorsomedial thalamus. After controlling for the whole-brain declines in absolute metabolism, relative increases in regional metabolism from waking to NREM were found bilaterally in the dorsal pontine tegmentum, hypothalamus, basal forebrain, ventral striatum, anterior cingulate cortex and extensive regions of the mesial temporal lobe, including the amygdala and hippocampus, and in the right dorsal parietal association cortex and primary somatosensory and motor cortices. The reductions in relative metabolism in NREM sleep compared with waking are consistent with prior findings from blood flow studies. The relative increases in glucose utilization in the basal forebrain, hypothalamus, ventral striatum, amygdala, hippocampus and pontine reticular formation are new observations that are in accordance with the view that NREM sleep is important to brain

  15. Individual cerebral metabolic deficits in Alzheimer's disease and amnestic mild cognitive impairment: an FDG PET study

    Energy Technology Data Exchange (ETDEWEB)

    Del Sole, Angelo; Lecchi, Michela; Lucignani, Giovanni [Unit of Nuclear Medicine, Hospital San Paolo, Institute of Radiological Sciences, University of Milan, Milan (Italy); Clerici, Francesca; Mariani, Claudio; Maggiore, Laura [University of Milan, Center for Research and Treatment on Cognitive Dysfunctions, Institute of Clinical Neurology, Department of Clinical Sciences, ' Luigi Sacco' Hospital, Milan (Italy); Chiti, Arturo [Clinical Institute Humanitas, Nuclear Medicine Department, Milan (Italy); Mosconi, Lisa [New York University School of Medicine, Department of Psychiatry, New York, NY (United States)

    2008-07-15

    The purpose of the study was the identification of group and individual subject patterns of cerebral glucose metabolism (CMRGlu) in patients with Alzheimer's disease (AD) and with amnestic mild cognitive impairment (aMCI). [{sup 18}F]fluorodeoxyglucose positron emission tomography (PET) studies and neuropsychological tests were performed in 16 aMCI patients (ten women, age 75 {+-} 8 years) and in 14 AD patients (ten women, age 75 {+-} 9 years). Comparisons between patient subgroups and with a control population were performed using Statistical Parametric Mapping. Clusters of low CMRGlu were observed bilaterally in the posterior cingulate cortex (PCC), in the precuneus, in the inferior parietal lobule and middle temporal gyrus of AD patients. In aMCI patients, reduced CMRGlu was found only in PCC. Areas of low CMRGlu in PCC were wider in AD compared to aMCI and extended to the precuneus, while low CMRGlu was found in the lateral parietal cortex in AD but not in aMCI patients. Individual subject pattern analysis revealed that 86% of AD patients had low CMRGlu in the PCC (including the precuneus in 71%), 71% in the temporal cortex, 64% in the parietal cortex and 35% in the frontal cortex. Among the aMCI patients, 56% had low CMRGlu in the PCC, 44% in the temporal cortex, 18% in the frontal cortex and none in the parietal cortex. This study demonstrates that both AD and aMCI patients have highly heterogeneous metabolic impairment. This potential of individual metabolic PET imaging in patients with AD and aMCI may allow timely identification of brain damage on individual basis and possibly help planning tailored early interventions. (orig.)

  16. Oxygen uptake and blood metabolic responses to a 400-m run.

    Science.gov (United States)

    Hanon, Christine; Lepretre, Pierre-Marie; Bishop, David; Thomas, Claire

    2010-05-01

    This study aimed to investigate the oxygen uptake and metabolic responses during a 400-m run reproducing the pacing strategy used in competition. A portable gas analyser was used to measure the oxygen uptake (VO2) of ten specifically trained runners racing on an outdoor track. The tests included (1) an incremental test to determine maximal VO2 (VO2max) and the velocity associated with VO2(max) (v - VO2max), (2) a maximal 400-m (400T) and 3) a 300-m running test (300T) reproducing the exact pacing pattern of the 400T. Blood lactate, bicarbonate concentrations [HCO3(-)], pH and arterial oxygen saturation were analysed at rest and 1, 4, 7, 10 min after the end of the 400 and 300T. The peak VO2 recorded during the 400T corresponded to 93.9 +/- 3.9% of VO2max and was reached at 24.4 +/- 3.2 s (192 +/- 22 m). A significant decrease in VO2 (P < 0.05) was observed in all subjects during the last 100 m, although the velocity did not decrease below v - VO2max. The VO2 in the last 5 s was correlated with the pH (r = 0.86, P < 0.0005) and [HCO3(-)] (r = 0.70, P < 0.05) measured at the end of 300T. Additionally, the velocity decrease observed in the last 100 m was inversely correlated with [HCO3(-)] and pH at 300T (r = -0.83, P < 0.001, r = -0.69, P < 0.05, respectively). These track running data demonstrate that acidosis at 300 m was related to both the VO2 response and the velocity decrease during the final 100 m of a 400-m run.

  17. Cerebral oxygenation after birth

    DEFF Research Database (Denmark)

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

    2014-01-01

    .19 p = 86.2% (CI 85.0-87.4%) for INVOS and FORE-SIGHT, respectively. The within-subject standard deviation during steady-state repeated measurements was 4.8% ± 0.86 for INVOS and 2.8% ± 0.5 for FORE-SIGHT. CONCLUSION...

  18. 3-Hydroxybutyrate regulates energy metabolism and induces BDNF expression in cerebral cortical neurons

    DEFF Research Database (Denmark)

    Marosi, Krisztina; Kim, Sang Woo; Moehl, Keelin

    2016-01-01

    . The mechanism by which 3OHB induces Bdnf gene expression involves generation of reactive oxygen species, activation of the transcription factor NF-κB, and activity of the histone acetyltransferase p300/EP300. Because BDNF plays important roles in synaptic plasticity and neuronal stress resistance, our findings...

  19. Nitric oxide and reactive oxygen species mediate metabolic changes in barley seed embryo during germination

    Directory of Open Access Journals (Sweden)

    Zhenguo eMa

    2016-02-01

    Full Text Available The levels of nitric oxide (NO and reactive oxygen species (ROS, ATP/ADP ratios, reduction levels of ascorbate and glutathione, expression of the genes encoding proteins involved in metabolism of NO and activities of the enzymes involved in fermentation and in metabolism of NO and ROS were studied in the embryos of germinating seeds of two barley (Hordeum vulgare L. cultivars differing in dormancy level. The level of NO production continuously increased after imbibition while the level of nitrosylated SH-groups in proteins increased. This corresponded to the decrease of free SH-groups in proteins. At early stage of germination (0-48 h postimbibition the genes encoding class 1 phytoglobin (the protein scavenging NO and S-nitrosoglutathione reductase (scavenging S-nitrosoglutathione were markedly expressed. More dormant cultivar exhibited lower ATP/ADP and ascorbate/dehydroascorbate ratios and lower lactate and alcohol dehydrogenase activities, while the production of NO and nitrosylation of proteins was higher as compared to the non-dormant cultivar. The obtained data indicate that at the onset of germination NO is actively generated causing nitrosylation of SH-groups and a switch from respiration to fermentation. After radicle protrusion the metabolism changes in a more reducing type as recorded by ratio of reduced and oxidized glutathione and ascorbate. The turnover of NO by the scavenging systems (phytoglobin, S-nitrosoglutathione reductase and interaction with ROS might contribute to the maintenance of redox and energy balance of germinating seeds and lead to alleviation of dormancy.

  20. Effect of Exercise Training on Enos Expression, NO Production and Oxygen Metabolism in Human Placenta

    Science.gov (United States)

    Ramírez-Vélez, Robinson; Bustamante, Juanita; Czerniczyniec, Analia; Aguilar de Plata, Ana C.; Lores-Arnaiz, Silvia

    2013-01-01

    Objective To determine the effects of combined aerobic and resistance exercise training during the second half of pregnancy on endothelial NOS expression (eNOS), nitric oxide (NO) production and oxygen metabolism in human placenta. Methods The study included 20 nulliparous in gestational week 16–20, attending prenatal care at three tertiary hospitals in Colombia who were randomly assigned into one of two groups: The exercise group (n = 10) took part in an exercise session three times a week for 12 weeks which consisted of: aerobic exercise at an intensity of 55–75% of their maximum heart rate for 60 min and 25 mins. Resistance exercise included 5 exercise groups circuit training (50 repetitions of each) using barbells (1–3 kg/exercise) and low-to-medium resistance bands. The control group (n = 10) undertook their usual physical activity. Mitochondrial and cytosol fractions were isolated from human placental tissue by differential centrifugation. A spectrophotometric assay was used to measure NO production in cytosolic samples from placental tissue and Western Blot technique to determine eNOS expression. Mitochondrial superoxide levels and hydrogen peroxide were measured to determine oxygen metabolism. Results Combined aerobic and resistance exercise training during pregnancy leads to a 2-fold increase in eNOS expression and 4-fold increase in NO production in placental cytosol (p = 0.05). Mitochondrial superoxide levels and hydrogen peroxide production rate were decreased by 8% and 37% respectively in the placental mitochondria of exercising women (p = 0.05). Conclusion Regular exercise training during the second half of pregnancy increases eNOS expression and NO production and decreases reactive oxygen species generation in human placenta. Collectively, these data demonstrate that chronic exercise increases eNOS/NO production, presumably by increasing endothelial shear stress. This adaptation may contribute to the beneficial effects of

  1. Direct neuronal glucose uptake Heralds activity-dependent increases in cerebral metabolism

    DEFF Research Database (Denmark)

    Lundgaard, Iben; Li, Baoman; Xie, Lulu

    2015-01-01

    Metabolically, the brain is a highly active organ that relies almost exclusively on glucose as its energy source. According to the astrocyte-to-neuron lactate shuttle hypothesis, glucose is taken up by astrocytes and converted to lactate, which is then oxidized by neurons. Here we show, using two...

  2. Improved cerebral energetics and ketone body metabolism in db/db mice

    DEFF Research Database (Denmark)

    Andersen, Jens V; Christensen, Sofie K; Nissen, Jakob D;

    2016-01-01

    It is becoming evident that type 2 diabetes mellitus is affecting brain energy metabolism. The importance of alternative substrates for the brain in type 2 diabetes mellitus is poorly understood. The aim of this study was to investigate whether ketone bodies are relevant candidates to compensate ...

  3. Differentiated effect of ageing on the enzymes of Krebs' cycle, electron transfer complexes and glutamate metabolism of non-synaptic and intra-synaptic mitochondria from cerebral cortex.

    Science.gov (United States)

    Villa, R F; Gorini, A; Hoyer, S

    2006-11-01

    The effect of ageing on the activity of enzymes linked to Krebs' cycle, electron transfer chain and glutamate metabolism was studied in three different types of mitochondria of cerebral cortex of 1-year old and 2-year old male Wistar rats. We assessed the maximum rate (V(max)) of the mitochondrial enzyme activities in non-synaptic perikaryal mitochondria, and in two populations of intra-synaptic mitochondria. The results indicated that: (i) in normal, steady-state cerebral cortex the values of the catalytic activities of the enzymes markedly differed in the various populations of mitochondria; (ii) in intra-synaptic mitochondria, ageing affected the catalytic properties of the enzymes linked to Krebs' cycle, electron transfer chain and glutamate metabolism; (iii) these changes were more evident in intra-synaptic "heavy" than "light" mitochondria. These results indicate a different age-related vulnerability of subpopulations of mitochondria in vivo located into synapses than non-synaptic ones.

  4. Impact of Nutrition on Cerebral Circulation and Cognition in the Metabolic Syndrome

    OpenAIRE

    Laura Mellendijk; Maximilian Wiesmann; Kiliaan, Amanda J

    2015-01-01

    The increasing prevalence of Metabolic Syndrome (MetS), defined as the clustering of abdominal obesity, dyslipidemia, hypertension, and hyperglycemia, appears to be driving the global epidemics cardiovascular disease (CVD) and type 2 diabetes mellitus (T2DM). Nutrition has a major impact on MetS and plays an important role in the prevention, development, and treatment of its features. Structural and functional alterations in the vasculature, associated with MetS, might form the link between M...

  5. Regional cerebral glucose metabolic changes in oculopalatal myoclonus: implication for neural pathways, underlying the disorder

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Sang Soo; Moon, So Young; Kim, Ji Soo; Kim, Sang Eun [College of Medicine, Seoul National University, Seoul (Korea, Republic of)

    2004-07-01

    Palatal myoclonus (PM) is characterized by rhythmic involuntary jerky movements of the soft palate of the throat. When associated with eye movements, it is called oculopalatal myoclonus (OPM). Ordinary PM is characterized by hypertrophic olivary degeneration, a trans-synaptic degeneration following loss of neuronal input to the inferior olivary nucleus due to an interruption of the Guillain-Mollaret triangle usually by a hemorrhage. However, the neural pathways underlying the disorder are uncertain. In an attempt to understand the pathologic neural pathways, we examined the metabolic correlates of this tremulous condition. Brain FDG PET scans were acquired in 8 patients with OPM (age, 49.9{+-}4.6 y: all males: 7 with pontine hemorrhage, 1 with diffuse brainstem infarction) and age-matched 50 healthy males (age, 50.7{+-} 9.0) and the regional glucose metabolism compared using SPM99. For group analysis, the hemispheres containing lesions were assigned to the right side of the brain. Patients with OPM had significant hypometabolism in the ipsilateral (to the lesion) brainstem and superior temporal and parahippocampal gyri (P < 0.05 corrected, k = 100). By contrast, there was significant hypermetabolism in the contralateral middle and inferior temporal gyri, thalamus, middle frontal gyrus and precuneus (P < 0.05 corrected, k=l00). Our data demonstrate the distinct metabolic changes between several ipsilateral and contralateral brain regions (hypometabolism vs. hypermetabolism) in patients with OPM. This may provide clues for understanding the neural pathways underlying the disorder.

  6. Metabolic suppression during protracted exposure to hypoxia in the jumbo squid, Dosidicus gigas, living in an oxygen minimum zone.

    Science.gov (United States)

    Seibel, Brad A; Häfker, N Sören; Trübenbach, Katja; Zhang, Jing; Tessier, Shannon N; Pörtner, Hans-Otto; Rosa, Rui; Storey, Kenneth B

    2014-07-15

    The jumbo squid, Dosidicus gigas, can survive extended forays into the oxygen minimum zone (OMZ) of the Eastern Pacific Ocean. Previous studies have demonstrated reduced oxygen consumption and a limited anaerobic contribution to ATP production, suggesting the capacity for substantial metabolic suppression during hypoxic exposure. Here, we provide a more complete description of energy metabolism and explore the expression of proteins indicative of transcriptional and translational arrest that may contribute to metabolic suppression. We demonstrate a suppression of total ATP demand under hypoxic conditions (1% oxygen, PO2 =0.8 kPa) in both juveniles (52%) and adults (35%) of the jumbo squid. Oxygen consumption rates are reduced to 20% under hypoxia relative to air-saturated controls. Concentrations of arginine phosphate (Arg-P) and ATP declined initially, reaching a new steady state (~30% of controls) after the first hour of hypoxic exposure. Octopine began accumulating after the first hour of hypoxic exposure, once Arg-P breakdown resulted in sufficient free arginine for substrate. Octopine reached levels near 30 mmol g(-1) after 3.4 h of hypoxic exposure. Succinate did increase through hypoxia but contributed minimally to total ATP production. Glycogenolysis in mantle muscle presumably serves to maintain muscle functionality and balance energetics during hypoxia. We provide evidence that post-translational modifications on histone proteins and translation factors serve as a primary means of energy conservation and that select components of the stress response are altered in hypoxic squids. Reduced ATP consumption under hypoxia serves to maintain ATP levels, prolong fuel store use and minimize the accumulation of acidic intermediates of anaerobic ATP-generating pathways during prolonged diel forays into the OMZ. Metabolic suppression likely limits active, daytime foraging at depth in the core of the OMZ, but confers an energetic advantage over competitors that must

  7. Cerebral perfusion and glucose metabolism in Alzheimer's disease and frontotemporal dementia: two sides of the same coin?

    Energy Technology Data Exchange (ETDEWEB)

    Verfaillie, Sander C.J.; Adriaanse, Sofie M.; Binnewijzend, Maja A.A.; Benedictus, Marije R.; Ossenkoppele, Rik [VU University Medical Centre, Department of Radiology and Nuclear Medicine, Amsterdam (Netherlands); VU University Medical Centre, Alzheimer Centre and Department of Neurology, P.O. Box 7057, Amsterdam (Netherlands); Wattjes, Mike P.; Lammertsma, Adriaan A.; Boellaard, Ronald; Berckel, Bart N.M. van; Barkhof, Frederik [VU University Medical Centre, Department of Radiology and Nuclear Medicine, Amsterdam (Netherlands); Pijnenburg, Yolande A.L.; Scheltens, Philip [VU University Medical Centre, Alzheimer Centre and Department of Neurology, P.O. Box 7057, Amsterdam (Netherlands); Flier, Wiesje M. van der [VU University Medical Centre, Alzheimer Centre and Department of Neurology, P.O. Box 7057, Amsterdam (Netherlands); VU University Medical Centre, Department of Epidemiology and Biostatistics, Amsterdam (Netherlands); Kuijer, Joost P.A. [VU University Medical Centre, Department of Physics and Medical Technology, Amsterdam (Netherlands)

    2015-10-15

    Alzheimer's disease (AD) and frontotemporal (FTD) dementia can be differentiated using [{sup 18}F]-2-deoxy-2-fluoro-D-glucose (FDG)-PET. Since cerebral blood flow (CBF) is related to glucose metabolism, our aim was to investigate the extent of overlap of abnormalities between AD and FTD. Normalized FDG-PET and arterial spin labelling (ASL-MRI)-derived CBF was measured in 18 AD patients (age, 64 ± 8), 12 FTD patients (age, 61 ± 8), and 10 controls (age, 56 ± 10). Voxel-wise comparisons, region-of-interest (ROI), correlation, and ROC curve analyses were performed. Voxel-wise comparisons showed decreased CBF and FDG uptake in AD compared with controls and FTD in both precuneus and inferior parietal lobule (IPL). Compared with controls and AD, FTD patients showed both hypometabolism and hypoperfusion in medial prefrontal cortex (mPFC). ASL and FDG were related in precuneus (r = 0.62, p < 0.001), IPL (r = 0.61, p < 0.001), and mPFC across groups (r = 0.74, p < 001). ROC analyses indicated comparable performance of perfusion and metabolism in the precuneus (AUC, 0.72 and 0.74), IPL (0.85 and 0.94) for AD relative to FTD, and in the mPFC in FTD relative to AD (both 0.68). Similar patterns of hypoperfusion and hypometabolism were observed in regions typically associated with AD and FTD, suggesting that ASL-MRI provides information comparable to FDG-PET. (orig.)

  8. Time courses of behavioral and regional cerebral metabolic responses to different doses of meta-chlorophenylpiperazine in awake rats.

    Science.gov (United States)

    Freo, U; Soncrant, T T; Ricchieri, G L; Wozniak, K M; Larson, D M; Rapoport, S I

    1990-03-19

    The time course and relation to dose of regional cerebral metabolic rates for glucose (rCMRglc) and of motor behavior were measured in awake male adult Fischer-344 rats after administration of meta-chlorophenylpiperazine (MCPP), a serotonin-1B receptor agonist. rCMRglc was determined, using the quantitative autoradiographic [14C]deoxyglucose technique, in 71 brain regions at 5, 15, 30 and 60 min after administration of MCPP 2.5 mg/kg i.p., and at 15 min after MCPP 25 and 40 mg/kg. The time course of performance on a rotating rod was measured periodically for 60 min after MCPP 2.5 mg/kg, a dose which impaired locomotion and reduced rCMRglc maximally at 15-30 min after its administration. At 15 min, rCMRglc declined significantly in 28 (40%) of the areas studied (mean decline 16%). Most regions affected were telencephalic or diencephalic, corresponding to the projection areas of serotonergic fibers arising from the raphe nuclei. After higher doses of MCPP, a behavioral serotonin syndrome was observed with both rCMRglc increases and decreases (25 mg/kg) or only rCMRglc increases (40 mg/kg). Whereas behavioral and metabolic activation induced by high doses of MCPP may result from stimulation at postsynaptic serotonin receptors, rCMRglc reductions and hypomotility produced by MCPP 2.5 mg/kg resemble the effects of serotonin receptor antagonists and suggest that, at this low dose, MCPP acts at modulatory serotonin autoreceptors to reduce endogenous serotonin release.

  9. 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.

  10. Oxygenation of Earth's atmosphere and its impact on the evolution of nitrogen-based metabolisms

    Science.gov (United States)

    Papineau, D.; Mojzsis, S. J.

    2002-12-01

    The evolution of metabolic pathways is closely linked to the evolution of the redox state of the terrestrial atmosphere. Nitrogen has been an essential biological element since the emergence of life when reduced nitrogen compounds (e.g. ammonia) were utilized in the prebiotic synthesis of proteins and nucleic acids. The nitrogen isotopic composition of sediments has been used to trace the origin of sedimentary organic matter in the rock record. Nitrogen is therefore suitable as a biosignature to trace the emergence of life on Earth or other planetary bodies as well as to follow the subsequent evolution of the biosphere in response to global redox changes. Evidence is strong that biological nitrogen fixation evolved very early in the history of life. The Last Common Ancestor (LCA) on Earth was most likely capable of nitrogen fixation as seen from the phylogenetic distribution of nitrogen-fixing organisms in both the domains of Bacteria and Archaea. Phylogenetic trees plotted with nitrogen-fixing gene (Nif) sequences from lineages of Bacteria and Archaea suggest that the Nif genes originated in a common ancestor of the two domains. Other phylogenetic analyses have also demonstrated that the paralogous duplication of the nifDK and nifEN operons, central to nitrogen fixation, predated the divergence of Archaea from Bacteria and therefore occurred prior to the emergence of the LCA. Although the same may be true for denitrification, this metabolic pathway probably did not become dominant until atmospheric pO2 increased between ~2.4 to 1.9 Ga during the Great Oxygenation Event (GOE). Recent work has shown a general depletion in 15N content of Archean (pre-2.5 Ga) relative to Phanerozoic (<540 Ma) kerogens. Studies have shown that the distribution of the δ15N values in kerogens shift from negative values in the Early Archean (from -6 to +6‰ with an average near 0‰ ) to approximately contemporary positive values (from +2 to +10‰ with an average at +6‰ ) by the

  11. Metabolic changers in oxygen transport in patients with diabetes mellitus type 2. Possibilities for correction

    Directory of Open Access Journals (Sweden)

    I Z Bondarenko

    2009-06-01

    Full Text Available Diabetes mellitus type 2 (DM2 - is an independent predictor of development of heart failure (HF. Spiroergometry - is a method for studying blood gas exchange parameters, commonly used for specification of HF. The purpose: 1. To study features of gas exchange at patients with DM2 without cardiovascular diseases in comparison with healthy control. 2. To estimate efficiency of metoprolol for correction of metabolic disturbances in patients with DM2. Materials and methods: 12 patients with DM2, aged 48,4±8, without history of cardiovascular diseases and 15 control subjects, aged 43,6±8 underwent cardio-pulmonary exercise test on treadmill, according to Bruce protocol. Exercise energy, VO2 peak, MET, VE max, VCO2 production were observed. Results: Patients with DM2 had a reduced exercise duration (p<0,001, lower peak oxygen consumption (p<0,001, VCO2 production and MET (p<0,005, than controls, representing the same state of hypoxia as in patients with ischemic heart disease (IHD of functional class 2. The introduction of metoprolol to patients with DM2 significantly increased exercise duration time and VCO2 production (p<0,005. Conclusions: 1. VO2 consumption in patients with DM2 is decreased to the same levels as in persons without DM2, who have IHD and HF. 2. Changes in oxygen-transport in persons with DM2 may serve as a marker of negative influence of the disease on cardiovascular system status. 3. Metoprolol improves parameters of cardio-respiratory system in patients with DM2.

  12. Age-related alterations in behavioral and cerebral metabolic responses to the serotonin agonist meta-chlorophenylpiperazine in rats.

    Science.gov (United States)

    Freo, U; Rapoport, S I; Soncrant, T T

    1991-01-01

    To determine the functional relevance of the age-related neurochemical changes that occur in brain serotonin systems during aging, we measured the effects of the serotonin receptor agonist meta-chlorophenylpiperazine (MCPP) on behavior and on regional cerebral metabolic rates for glucose (rCMRglc) in awake rats. rCMRglc was determined in 74 regions of Fischer-344 rats aged 3, 12 and 24 months, at 15 and 90 min after MCPP 2.5 mg/kg IP, using the quantitative, autoradiographic [14C]2-deoxy-D-glucose technique. The time-course of motor performance following MCPP was assessed with a rotating rod. MCPP impaired motor performance in all ages maximally at 15-30 min. Three-month-old rats recovered completely within 60 min, whereas 12-month-old animals exhibited partial recovery and 24-month-old rats did not recover by 120 min. At 15 min after MCPP, rCMRglc was reduced in 51 of the 74 studied regions (overall decrease, 20%) of 3-month-old rats, in 21 regions (13% decrease) of 12-month-old rats and in 14 regions (2% decrease) of 24-month-old animals. Similar MCPP brain concentrations were achieved at 15 min in rats of all ages. The results suggest that the functional integrity of serotonergic transmission is reduced in aged rats and that the dysregulation is presynaptic.

  13. Cerebral metabolic responses to meta-chlorophenylpiperazine are reduced during its chronic administration to young and aged rats.

    Science.gov (United States)

    Freo, U; Larson, D M; Soncrant, T T

    1993-01-01

    The effects of the 5-HT agonist meta-chlorophenylpiperazine (MCPP) on regional cerebral metabolic rates for glucose (rCMRglc) were measured in 3- and 24-month-old rats that were not pretreated or were pretreated for 2 weeks with continuous infusion of saline or MCPP. rCMRglc were measured using the quantitative autoradiographic [14C]2-deoxy-D-glucose technique in 71 brain regions at 15 min after acute administration of MCPP 2.5 mg/kg. In the absence of chronic pretreatment, intraperitoneal MCPP 2.5 mg/kg produced widespread rCMRglc reductions (41 brain areas) in 3-month-old rats and more limited rCMRglc decreases (8 brain areas) in 24-month-old rats. After chronic treatment, MCPP failed to reduce rCMRglc in any region of either group of rats. These findings indicate that mechanisms of downregulation of response to MCPP are functional in young and aged rats and suggest that the age-related reduction in rCMRglc responses to acute MCPP in non-pretreated animals may be due to compensation for age-related losses of 5-HT terminals.

  14. Regulation of cerebral CYP2D alters tramadol metabolism in the brain: interactions of tramadol with propranolol and nicotine.

    Science.gov (United States)

    Wang, Qiaoli; Han, Xiaotong; Li, Jian; Gao, Xinghui; Wang, Yan; Liu, Mingzhou; Dong, Guicheng; Yue, Jiang

    2015-04-01

    1. Cytochrome P450 2D (CYP2D) protein is widely expressed across brain regions in human and rodents. We investigated the interactions between tramadol, a clinically used analgesic, and brain CYP2D regulators, by establishing concentration-time curves of tramadol and O-desmethyltramadol (M1) in rat cerebrospinal fluid (CSF) and plasma, as well as by analyzing the analgesia-time course of tramadol. 2. Propranolol (20 μg, intracerebroventricular injection), CYP2D inhibitor, prolonged the elimination t1/2 of tramadol (40 mg/kg, intraperitoneal injection) in the CSF; meanwhile, lower Cmax and AUC0-∞ values of M1 were observed. Nicotine (1 mg base/kg, subcutaneous injection, seven days), brain CYP2D inducer, induced a shorter Tmax and elevated Cmax of M1 in CSF. No differences in the peripheral metabolism of tramadol were observed following propranolol and nicotine pretreatment. Nicotine increased areas under the analgesia-time curve (AUC) for 0-45 min and 0-90 min of tramadol, which was attenuated by propranolol administration. The analgesic actions of tramadol positively correlated with cerebral M1 concentration. 3. The results suggest that the regulation of brain CYP2D by xenobiotics may cause drug-drug interactions (DDIs) of tramadol. Brain CYPs may play an important role in DDIs of centrally active substances.

  15. Differential contribution of key metabolic substrates and cellular oxygen in HIF signalling

    Energy Technology Data Exchange (ETDEWEB)

    Zhdanov, Alexander V., E-mail: a.zhdanov@ucc.ie [School of Biochemistry and Cell Biology, University College Cork, Cavanagh Pharmacy Building, College Road, Cork (Ireland); Waters, Alicia H.C. [School of Biochemistry and Cell Biology, University College Cork, Cavanagh Pharmacy Building, College Road, Cork (Ireland); Golubeva, Anna V. [Alimentary Pharmabiotic Centre, University College Cork, Bioscience Institute, Western Road, Cork (Ireland); Papkovsky, Dmitri B. [School of Biochemistry and Cell Biology, University College Cork, Cavanagh Pharmacy Building, College Road, Cork (Ireland)

    2015-01-01

    Changes in availability and utilisation of O{sub 2} and metabolic substrates are common in ischemia and cancer. We examined effects of substrate deprivation on HIF signalling in PC12 cells exposed to different atmospheric O{sub 2}. Upon 2–4 h moderate hypoxia, HIF-α protein levels were dictated by the availability of glutamine and glucose, essential for deep cell deoxygenation and glycolytic ATP flux. Nuclear accumulation of HIF-1α dramatically decreased upon inhibition of glutaminolysis or glutamine deprivation. Elevation of HIF-2α levels was transcription-independent and associated with the activation of Akt and Erk1/2. Upon 2 h anoxia, HIF-2α levels strongly correlated with cellular ATP, produced exclusively via glycolysis. Without glucose, HIF signalling was suppressed, giving way to other regulators of cell adaptation to energy crisis, e.g. AMPK. Consequently, viability of cells deprived of O{sub 2} and glucose decreased upon inhibition of AMPK with dorsomorphin. The capacity of cells to accumulate HIF-2α decreased after 24 h glucose deprivation. This effect, associated with increased AMPKα phosphorylation, was sensitive to dorsomorphin. In chronically hypoxic cells, glutamine played no major role in HIF-2α accumulation, which became mainly glucose-dependent. Overall, the availability of O{sub 2} and metabolic substrates intricately regulates HIF signalling by affecting cell oxygenation, ATP levels and pathways involved in production of HIF-α. - Highlights: • Gln and Glc regulate HIF levels in hypoxic cells by maintaining low O{sub 2} and high ATP. • HIF-α levels under anoxia correlate with cellular ATP and critically depend on Glc. • Gln and Glc modulate activity of Akt, Erk and AMPK, regulating HIF production. • HIF signalling is differentially inhibited by prolonged Glc and Gln deprivation. • Unlike Glc, Gln plays no major role in HIF signalling in chronically hypoxic cells.

  16. Pattern of cerebral glucose metabolism on F-18 FDG brain PET during vomiting and symptom free periods in cyclic vomiting syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yu Kyeong; Lee, Dong Soo; Kang, Eun Joo; Seo, Jeong Kee; Yeo, Jeong Seok; Chung, June Key; Lee, Myung Chul [College of Medicine, Seoul National Univ., Seoul (Korea, Republic of)

    2001-06-01

    Cyclic Vomiting Syndrome (CVS) is characterized by recurrent, periodic, self-limiting vomiting. However, its pathogenesis is not yet established. We investigated the changes of the cerebral glucose metabolism using F-18 FDG during the vomiting attack and symptom free period in two children with CVS. FDG PET study showed the markedly increased metabolism in both temporal lobes and also in the medulla and cerebellum during the vomiting period. Also, FDG PET showed the decreased metabolism in the parieto-occipital and occipital areas during the in vomiting period. The area with decreased metabolism seemed to be related with the region showing abnormalities in EEG and perfusion SPECT studies. We expect that what we observed would be a helpful finding in clarifying the pathogenesis of the CVS.

  17. Ventilation rates and activity levels of juvenile jumbo squid under metabolic suppression in the oxygen minimum zone.

    Science.gov (United States)

    Trübenbach, Katja; Pegado, Maria R; Seibel, Brad A; Rosa, Rui

    2013-02-01

    The Humboldt (jumbo) squid, Dosidicus gigas, is a part-time resident of the permanent oxygen minimum zone (OMZ) in the Eastern Tropical Pacific and, thereby, it encounters oxygen levels below its critical oxygen partial pressure. To better understand the ventilatory mechanisms that accompany the process of metabolic suppression in these top oceanic predators, we exposed juvenile D. gigas to the oxygen levels found in the OMZ (1% O(2), 1 kPa, 10 °C) and measured metabolic rate, activity cycling patterns, swimming mode, escape jet (burst) frequency, mantle contraction frequency and strength, stroke volume and oxygen extraction efficiency. In normoxia, metabolic rate varied between 14 and 29 μmol O(2) g(-1) wet mass h(-1), depending on the level of activity. The mantle contraction frequency and strength were linearly correlated and increased significantly with activity level. Additionally, an increase in stroke volume and ventilatory volume per minute was observed, followed by a mantle hyperinflation process during high activity periods. Squid metabolic rate dropped more than 75% during exposure to hypoxia. Maximum metabolic rate was not achieved under such conditions and the metabolic scope was significantly decreased. Hypoxia changed the relationship between mantle contraction strength and frequency from linear to polynomial with increasing activity, indicating that, under hypoxic conditions, the jumbo squid primarily increases the strength of mantle contraction and does not regulate its frequency. Under hypoxia, jumbo squid also showed a larger inflation period (reduced contraction frequency) and decreased relaxed mantle diameter (shortened diffusion pathway), which optimize oxygen extraction efficiency (up to 82%/34%, without/with consideration of 60% potential skin respiration). Additionally, they breathe 'deeply', with more powerful contractions and enhanced stroke volume. This deep-breathing behavior allows them to display a stable ventilatory volume per

  18. Metabolic profiling reveals ethylene mediated metabolic changes and a coordinated adaptive mechanism of 'Jonagold' apple to low oxygen stress.

    Science.gov (United States)

    Bekele, Elias A; Beshir, Wasiye F; Hertog, Maarten L A T M; Nicolai, Bart M; Geeraerd, Annemie H

    2015-11-01

    Apples are predominantly stored in controlled atmosphere (CA) storage to delay ripening and prolong their storage life. Profiling the dynamics of metabolic changes during ripening and CA storage is vital for understanding the governing molecular mechanism. In this study, the dynamics of the primary metabolism of 'Jonagold' apples during ripening in regular air (RA) storage and initiation of CA storage was profiled. 1-Methylcyclopropene (1-MCP) was exploited to block ethylene receptors and to get insight into ethylene mediated metabolic changes during ripening of the fruit and in response to hypoxic stress. Metabolic changes were quantified in glycolysis, the tricarboxylic acid (TCA) cycle, the Yang cycle and synthesis of the main amino acids branching from these metabolic pathways. Partial least square discriminant analysis of the metabolic profiles of 1-MCP treated and control apples revealed a metabolic divergence in ethylene, organic acid, sugar and amino acid metabolism. During RA storage at 18°C, most amino acids were higher in 1-MCP treated apples, whereas 1-aminocyclopropane-1-carboxylic acid (ACC) was higher in the control apples. The initial response of the fruit to CA initiation was accompanied by an increase of alanine, succinate and glutamate, but a decline in aspartate. Furthermore, alanine and succinate accumulated to higher levels in control apples than 1-MCP treated apples. The observed metabolic changes in these interlinked metabolites may indicate a coordinated adaptive strategy to maximize energy production.

  19. Olanzapine-induced cerebral metabolic changes related to symptom improvement in schizophrenia.

    Science.gov (United States)

    Molina, Vicente; Gispert, Juan D; Reig, Santiago; Pascau, Javier; Martínez, Raúl; Sanz, Javier; Palomo, Tomás; Desco, Manuel

    2005-01-01

    The pattern of brain metabolic changes produced by olanzapine has yet to be described, despite the theoretical and clinical interest of this new antipsychotic. We studied a group of 17 schizophrenic patients who underwent two fluoro-deoxyglucose-positron emission tomography (FDG-PET) studies under two different conditions: a baseline scan during treatment with either conventional antipsychotics (n=15) or risperidone (n=2) and a second scan performed 17-24 weeks after switching to olanzapine. PET scans were obtained while performing a standard cognitive paradigm (Continuous Performance Test) and analysed by means of Statistical Parametric Mapping. No significant metabolic changes were found in the comparison between pre- and post-olanzapine conditions. A brain map of the statistical power of our design showed that changes up to 3% in the frontal and up to 8% in the occipital region were not likely to exist (1-beta=0.8). The degree of improvement in positive symptoms was related to the amount of activity decrease in the right orbital region and to the amount of activity increase in the primary visual area. Improvement in negative symptoms was associated with an activity increase in the dorsal prefrontal cortex, and a higher baseline activity in both temporal poles. These correlation patterns suggest that the functional mechanism of action of olanzapine may share traits from both typical and atypical neuroleptics.

  20. Lactate as a cerebral metabolic fuel for glucose-6-phosphatase deficient children.

    Science.gov (United States)

    Fernandes, J; Berger, R; Smit, G P

    1984-04-01

    The main substrates for brain energy metabolism were measured in blood samples taken from the carotid artery and the internal jugular bulb of four children with glycogen storage disease caused by deficiency of glucose-6-phosphatase. Multiple paired arterial and venous blood samples were analyzed for glucose, lactate, pyruvate, D-beta-hydroxybutyrate, acetoacetate, glycerol and O2, and the arteriovenous differences of the concentrations were calculated. In the first three patients the substrates were measured in two successive conditions with lower and higher glucose-intake, respectively, inducing reciprocally higher and lower concentrations of blood lactate. In the fourth patient medium chain triglycerides were administered simultaneously with the glucose-containing gastric drip feeding. Lactate appeared to be taken up significantly. It consumed, if completely oxidized, between 40-50% of the total O2 uptake in most cases. Only once in one patient the uptake of lactate switched to its release, when the blood lactate level decreased to normal. D-beta-hydroxybutyrate and acetoacetate arteriovenous (A-V) differences were small to negligible and these ketone bodies, therefore, did not contribute substantially to the brain's energy expenditure. Glycerol was not metabolized by the brain. Lactate thus appeared to be the second brain fuel next to glucose. It may protect the brain against fuel depletion in case of hypoglycemia.

  1. The deep cerebral stimulation of the under thalamic nucleus modifies the cerebral metabolism in {sup 18}FDG-Tep of obsessive compulsive patients; La stimulation cerebrale profonde du noyau sous thalamique modifie le metabolisme cerebral en 18FDG-TEP des patients obsessionnels compulsifs

    Energy Technology Data Exchange (ETDEWEB)

    Le Jeune, F.; Garin, E. [Service de medecine nucleaire, centre Eugene-Marquis, Rennes, (France); Verin, M.; Peron, J. [service de neurologie, CHU Pontchaillou, Rennes, (France); Mallet, L.; Yelnik, J. [Inserm, Avenir Team, Behavior, Emotion and Basal Ganglia, IFR 70, Pitie-Salpetriere, Paris, (France); Kreps, M.O. [Inserm U796, service de psychiatrie, hopital Sainte-Anne, Paris, (France); Drapier, D.; Millet, B. [service de psychiatrie adulte, centre hospitalier Guillaume-Regnier, Rennes, (France)

    2009-05-15

    The aim of this work was to find again this orbito-frontal hyper metabolism among the resistant obsessive compulsive disorder patients that are going to benefit of a deep cerebral stimulation of the under thalamus nucleus and to demonstrate that this new therapy approach leads a reduction of the metabolism in this area in correlation with the clinical improvement. It is about the first study realized in isotopic functional imaging on ten resistant compulsive disorder patients treated by bilateral deep cerebral stimulation of the under thalamus nucleus. It shows that the treatment efficiency is in relation with a reduction of the glucide metabolism in the right orbito-frontal cortex. It suggests equally that the under thalamus nucleus would be functionally linked to the orbito-frontal cortex. (N.C.)

  2. Oxygen-glucose deprivation inducing B1 RNA inhibits neuronal cells metabolic activity by NLRP3 and associated proinflammatory cytokines production.

    Science.gov (United States)

    Wang, Li; Wang, Weihua; Zhang, Lei; Dai, Peng; Wang, Kai; Hui, Hao; Rao, Wei; Peng, Cheng; Yang, Jinghua; Yan, Zhen; Fei, Zhou

    2015-02-19

    Cerebral ischemia occurs when blood flow to part of the brain is obstructed, which can result in oxygen and glucose deprivation (OGD) and neuronal damage. However, the mechanisms remain poorly understood. The present study investigated the production and effects of double-stranded RNA (dsRNA) induced by OGD in neuronal cells. By confocal microscopy, dsRNA containing B1 and B2 RNA, was found accumulating in HT22 cells under OGD treatment. The sequence of B1 RNA was identified and transfected into HT22 cells. Interestingly, B1 RNA induced transcription and expression of NLRP3, interleukin (IL)-1β, and tumor necrosis factor (TNF)-α, which was similar to the effects of OGD treatment. Moreover, HT22 cell growth inhibition and proinflammatory cytokines production induced by OGD and B1 RNA treatment were down-regulated by NLRP3 knock-down. These findings suggest that B1 RNA induced by OGD forms as dsRNA and inhibits neuronal cell metabolic activity by regulating the NLRP3 and associated proinflammatory cytokines production.

  3. Heterogeneity in a Suburban River Network: Understanding the Impact of Fluvial Wetlands on Dissolved Oxygen and Metabolism in Headwater Streams

    Science.gov (United States)

    Cain, J. S.; Wollheim, W. M.; Sheehan, K.; Lightbody, A.

    2014-12-01

    Low dissolved oxygen content in rivers threatens fish populations, aquatic organisms, and the health of entire ecosystems. River systems with high fluvial wetland abundance and organic matter, may result in high metabolism that in conjunction with low re-aeration rates, lead to low oxygen conditions. Increasing abundance of beaver ponds in many areas may exacerbate this phenomenon. This research aims to understand the impact of fluvial wetlands, including beaver ponds, on dissolved oxygen (D.O.) and metabolism throughout the headwaters of the Ipswich R. watershed, MA, USA. In several fluvial wetland dominated systems, we measured diel D.O. and metabolism in the upstream inflow, the surface water transient storage zones of fluvial wetland sidepools, and at the outflow to understand how the wetlands modify dissolved oxygen. D.O. was also measured longitudinally along entire surface water flow paths (x-y km long) to determine how low levels of D.O. propagate downstream. Nutrient samples were also collected to understand how their behavior was related to D.O. behavior. Results show that D.O. in fluvial wetlands has large swings with periods of very low D.O. at night. D.O. swings were also seen in downstream outflow, though lagged and somewhat attenuated. Flow conditions affect the level of inundation and the subsequent effects of fluvial wetlands on main channel D.O.. Understanding the D.O. behavior throughout river systems has important implications for the ability of river systems to remove anthropogenic nitrogen.

  4. Voxel-based statistical analysis of cerebral glucose metabolism in the rat cortical deafness model by 3D reconstruction of brain from autoradiographic images

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae Sung; Park, Kwang Suk [Seoul National University College of Medicine, Department of Nuclear Medicine, 28 Yungun-Dong, Chongno-Ku, Seoul (Korea); Seoul National University College of Medicine, Department of Biomedical Engineering, Seoul (Korea); Ahn, Soon-Hyun; Oh, Seung Ha; Kim, Chong Sun; Chung, June-Key; Lee, Myung Chul [Seoul National University College of Medicine, Department of Otolaryngology, Head and Neck Surgery, Seoul (Korea); Lee, Dong Soo; Jeong, Jae Min [Seoul National University College of Medicine, Department of Nuclear Medicine, 28 Yungun-Dong, Chongno-Ku, Seoul (Korea)

    2005-06-01

    Animal models of cortical deafness are essential for investigation of the cerebral glucose metabolism in congenital or prelingual deafness. Autoradiographic imaging is mainly used to assess the cerebral glucose metabolism in rodents. In this study, procedures for the 3D voxel-based statistical analysis of autoradiographic data were established to enable investigations of the within-modal and cross-modal plasticity through entire areas of the brain of sensory-deprived animals without lumping together heterogeneous subregions within each brain structure into a large region of interest. Thirteen 2-[1-{sup 14}C]-deoxy-D-glucose autoradiographic images were acquired from six deaf and seven age-matched normal rats (age 6-10 weeks). The deafness was induced by surgical ablation. For the 3D voxel-based statistical analysis, brain slices were extracted semiautomatically from the autoradiographic images, which contained the coronal sections of the brain, and were stacked into 3D volume data. Using principal axes matching and mutual information maximization algorithms, the adjacent coronal sections were co-registered using a rigid body transformation, and all sections were realigned to the first section. A study-specific template was composed and the realigned images were spatially normalized onto the template. Following count normalization, voxel-wise t tests were performed to reveal the areas with significant differences in cerebral glucose metabolism between the deaf and the control rats. Continuous and clear edges were detected in each image after registration between the coronal sections, and the internal and external landmarks extracted from the spatially normalized images were well matched, demonstrating the reliability of the spatial processing procedures. Voxel-wise t tests showed that the glucose metabolism in the bilateral auditory cortices of the deaf rats was significantly (P<0.001) lower than that in the controls. There was no significantly reduced metabolism in

  5. Hypoxia and oxygenation induce a metabolic switch between pentose phosphate pathway and glycolysis in glioma stem-like cells.

    Science.gov (United States)

    Kathagen, Annegret; Schulte, Alexander; Balcke, Gerd; Phillips, Heidi S; Martens, Tobias; Matschke, Jakob; Günther, Hauke S; Soriano, Robert; Modrusan, Zora; Sandmann, Thomas; Kuhl, Carsten; Tissier, Alain; Holz, Mareike; Krawinkel, Lutz A; Glatzel, Markus; Westphal, Manfred; Lamszus, Katrin

    2013-11-01

    Fluctuations in oxygen tension during tissue remodeling impose a major metabolic challenge in human tumors. Stem-like tumor cells in glioblastoma, the most common malignant brain tumor, possess extraordinary metabolic flexibility, enabling them to initiate growth even under non-permissive conditions. We identified a reciprocal metabolic switch between the pentose phosphate pathway (PPP) and glycolysis in glioblastoma stem-like (GS) cells. Expression of PPP enzymes is upregulated by acute oxygenation but downregulated by hypoxia, whereas glycolysis enzymes, particularly those of the preparatory phase, are regulated inversely. Glucose flux through the PPP is reduced under hypoxia in favor of flux through glycolysis. PPP enzyme expression is elevated in human glioblastomas compared to normal brain, especially in highly proliferative tumor regions, whereas expression of parallel preparatory phase glycolysis enzymes is reduced in glioblastomas, except for strong upregulation in severely hypoxic regions. Hypoxia stimulates GS cell migration but reduces proliferation, whereas oxygenation has opposite effects, linking the metabolic switch to the "go or grow" potential of the cells. Our findings extend Warburg's observation that tumor cells predominantly utilize glycolysis for energy production, by suggesting that PPP activity is elevated in rapidly proliferating tumor cells but suppressed by acute severe hypoxic stress, favoring glycolysis and migration to protect cells against hypoxic cell damage.

  6. Effect of ageing and ischemia on enzymatic activities linked to Krebs' cycle, electron transfer chain, glutamate and aminoacids metabolism of free and intrasynaptic mitochondria of cerebral cortex.

    Science.gov (United States)

    Villa, Roberto Federico; Gorini, Antonella; Hoyer, Siegfried

    2009-12-01

    The effect of ageing and the relationships between the catalytic properties of enzymes linked to Krebs' cycle, electron transfer chain, glutamate and aminoacid metabolism of cerebral cortex, a functional area very sensitive to both age and ischemia, were studied on mitochondria of adult and aged rats, after complete ischemia of 15 minutes duration. The maximum rate (Vmax) of the following enzyme activities: citrate synthase, malate dehydrogenase, succinate dehydrogenase for Krebs' cycle; NADH-cytochrome c reductase as total (integrated activity of Complex I-III), rotenone sensitive (Complex I) and cytochrome oxidase (Complex IV) for electron transfer chain; glutamate dehydrogenase, glutamate-oxaloacetate-and glutamate-pyruvate transaminases for glutamate metabolism were assayed in non-synaptic, perikaryal mitochondria and in two populations of intra-synaptic mitochondria, i.e., the light and heavy mitochondrial fraction. The results indicate that in normal, steady-state cerebral cortex, the value of the same enzyme activity markedly differs according (a) to the different populations of mitochondria, i.e., non-synaptic or intra-synaptic light and heavy, (b) and respect to ageing. After 15 min of complete ischemia, the enzyme activities of mitochondria located near the nucleus (perikaryal mitochondria) and in synaptic structures (intra-synaptic mitochondria) of the cerebral tissue were substantially modified by ischemia. Non-synaptic mitochondria seem to be more affected by ischemia in adult and particularly in aged animals than the intra-synaptic light and heavy mitochondria. The observed modifications in enzyme activities reflect the metabolic state of the tissue at each specific experimental condition, as shown by comparative evaluation with respect to the content of energy-linked metabolites and substrates. The derangements in enzyme activities due to ischemia is greater in aged than in adult animals and especially the non-synaptic and the intra-synaptic light

  7. Acute effects of nicotine and smoking on blood flow, tissue oxygen, and aerobe metabolism of the skin and subcutis

    DEFF Research Database (Denmark)

    Sørensen, Lars Tue; Jørgensen, Stig; Petersen, Lars J

    2009-01-01

    and subcutaneous blood flow (QBF, SqBF) was assessed by Laser Doppler and 133Xe clearance. Tissue oxygen tension (TO(2)) was measured by a LICOX O(2)-electrode. Tissue glucose and lactate (Tgluc, Tlact) were assessed by microdialysis. The parameters were studied after intravenous infusion of 1.0 mg nicotine......, smoking of one cigarette, arterial occlusion, and reperfusion. RESULTS: Nicotine infusion decreased SqBF from 4.2 +/- 2.0 to 3.1 +/- 1.2 mL/100 g tissue/min (P ... by smoking, which distinctly decreases tissue blood flow, oxygen tension, and aerobe metabolism independent of smoking status....

  8. Cerebral metabolism in dogs assessed by (18)F-FDG PET: a pilot study to understand physiological changes in behavioral disorders in dogs.

    Science.gov (United States)

    Irimajiri, Mami; Miller, Michael A; Green, Mark A; Jaeger, Christine B; Luescher, Andrew U; Hutchins, Gary D

    2010-01-01

    The positron emission tomography (PET) imaging technique, which is utilized in human behavior and psychiatric disorder research, was performed on the brains of clinically normal mixed breed dogs, 3 hound-type (long floppy ears) mixed breed dogs and 3 non-hound retriever-type mixed breed dogs. Glucose metabolism was obtained with F-18 fluorodeoxyglucose (FDG), and quantitative analysis was performed by standardized uptake value (SUV) measurement. Magnetic resonance (MR) images were obtained in each dog, and these images were superimposed on PET images to identify anatomical locations. The glucose metabolism in each region of interest was compared between the three hound-type dogs and 3 non-hound-type dogs. The two anatomically different types of dog were compared to assess whether breed-typical behavioral tendencies (e.g., sniffing behavior in hound-type dogs, staring and retrieving in Labrador-type dogs) are reflected in baseline brain metabolic activity. There were no significant differences between the hound-type dogs and non-hound-type dogs in cerebral SUV values. These data might serve as normal canine cerebral metabolism data for FDG PET studies in dogs and form the basis for investigations into behavioral disorders in dogs such as compulsive disorder, anxiety disorders and cognitive dysfunction.

  9. Interregional cerebral metabolic associativity during a continuous performance task (Part I): healthy adults.

    Science.gov (United States)

    Willis, Mark W; Benson, Brenda E; Ketter, Terence A; Kimbrell, Tim A; George, Mark S; Speer, Andrew M; Herscovitch, Peter; Post, Robert M

    2008-10-30

    One emerging hypothesis regarding psychiatric illnesses is that they arise from the dysregulation of normal circuits or neuroanatomical patterns. In order to study mood disorders within this framework, we explored normal metabolic associativity patterns in healthy volunteers as a prelude to examining the same relationships in affectively ill patients (Part II). We applied correlational analyses to regional brain activity as measured with FDG-PET during an auditory continuous performance task (CPT) in 66 healthy volunteers. This simple attention task controlled for brain activity that otherwise might vary amongst affective and cognitive states. There were highly significant positive correlations between homologous regions in the two hemispheres in thalamic, extrapyramidal, orbital frontal, medial temporal and cerebellar areas. Dorsal frontal, lateral temporal, cingulate, and especially insula, and inferior parietal areas showed less significant homologous associativity, suggesting more specific lateralized function. The medulla and bilateral thalami exhibited the most diverse interregional associations. A general pattern emerged of cortical regions covarying inversely with subcortical structures, particularly the frontal cortex with cerebellum, amygdala and thalamus. These analytical data may help to confirm known functional and neuroanatomical relationships, elucidate others as yet unreported, and serve as a basis for comparison to patients with psychiatric illness.

  10. Early Oxygen-Utilization and Brain Activity in Preterm Infants

    NARCIS (Netherlands)

    Tataranno, ML; Alderliesten, Thomas; De Vries, Linda S.; Groenendaal, Floris; Toet, MC; Lemmers, Petra M A; van de Vosse, R.; Van Bel, Frank; Benders, Manon J N L

    2015-01-01

    The combined monitoring of oxygen supply and delivery using Near-InfraRed spectroscopy (NIRS) and cerebral activity using amplitude-integrated EEG (aEEG) could yield new insights into brain metabolism and detect potentially vulnerable conditions soon after birth. The relationship between NIRS and qu

  11. Metabolism of Reactive Oxygen Species in the Cytoplasmic Male-Sterile Cotton Anther

    Institute of Scientific and Technical Information of China (English)

    JIANG Pei-dong; ZHU Yun-guo; WANG Xiao-ling; ZHU Wei; ZHANG Xiao-quan; XIE Hai-yan; WANG Xue-de

    2007-01-01

    Reactive oxygen species (ROS) in plant cell, including superoxide (O2-·), hydrogen peroxide (H2O2), and malondialdehyde (MDA), are thought to be important inducible factors of cell apoptosis if excessively accumulated in cells. To elucidate the metabolic mechanism of ROS production and scavenging in anthers of the cytoplasmic male-sterile (CMS) cotton,CMS line, maintainer, and hybrid F1 anthers, were employed for studying the relationship between CMS and metabolism of ROS, by comparing ROS changes in the sterile and fertile anthers at different developmental stages. The results showed that during the abortion preliminary stage (sporogenous cell division stage), anthers of CMS line had higher contents of O2-·, H2O2, and MDA than those of maintainer or hybrid F1. Simultaneously, the higher activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) in scavenging ROS were measured in the anthers of the CMS line,indicating that an increase of ROS in anthers of abortion preliminary stage had an inducible effect on the antioxidant enzymes. But during the abortion peak of CMS anther (pollen mother cell meiosis stage), on the one hand, contents of O2-·,H2O2, and MDA were extraordinarily high in CMS anthers, on the other hand, the activities of SOD, CAT, and POD were excessively low, which disrupted the balance between the production and elimination of ROS and led to pollen mother cells apoptosis at this stage. In the following two stages (uninucleate microspore stage and mature pollen stage), the contents of O2-· and H2O2 in the aborted anthers were approximated to contents in the fertile anthers of the maintainer and hybrid F1. However, MDA contents were continuously raised and enzymic activities of SOD, CAT, and POD were consistently decreased in sterile anthers, which indicated that ROS still had harmful effects on the anthers after the apoptosis of the male cells. Excessive accumulation of O2-·, H2O2, and MDA and significant reduction of ROS

  12. [Oxygen metabolism in the body during substitution of nitrogen by helium in the air].

    Science.gov (United States)

    Troshikhin, G V; Isaakian, L A; Bekirova, G G

    1975-01-01

    The total gas exchange, body temperature, content of free oxygen in the quadriceps muscle and its changes upon oxygen inhalation of a known dosage (oxygen test) were measured in the Wistar rats during their one-hour exposure to a helium-oxygen atmosphere (21%) at 25 degrees C. In this atmosphere the animals displayed a 1.8 degrees decline in the body temperature, a 20.5% increase in the gas exchange and a 26% decrease of oxygen in the muscular tissue as compared with the respective parameters in the air. After the experiment during the first 20 min exposure to the normal atmosphere oxygen tests were 10-15% lower than before the experiment. These findings give evidence for an increase of oxygen exchange in the muscles of animals exposed to the helium-oxygen atmosphere at a temperature below the comfortable level.

  13. Cerebral Glucose Metabolism is Associated with Verbal but not Visual Memory Performance in Community-Dwelling Older Adults.

    Science.gov (United States)

    Gardener, Samantha L; Sohrabi, Hamid R; Shen, Kai-Kai; Rainey-Smith, Stephanie R; Weinborn, Michael; Bates, Kristyn A; Shah, Tejal; Foster, Jonathan K; Lenzo, Nat; Salvado, Olivier; Laske, Christoph; Laws, Simon M; Taddei, Kevin; Verdile, Giuseppe; Martins, Ralph N

    2016-03-31

    Increasing evidence suggests that Alzheimer's disease (AD) sufferers show region-specific reductions in cerebral glucose metabolism, as measured by [18F]-fluoro-2-deoxyglucose positron emission tomography (18F-FDG PET). We investigated preclinical disease stage by cross-sectionally examining the association between global cognition, verbal and visual memory, and 18F-FDG PET standardized uptake value ratio (SUVR) in 43 healthy control individuals, subsequently focusing on differences between subjective memory complainers and non-memory complainers. The 18F-FDG PET regions of interest investigated include the hippocampus, amygdala, posterior cingulate, superior parietal, entorhinal cortices, frontal cortex, temporal cortex, and inferior parietal region. In the cohort as a whole, verbal logical memory immediate recall was positively associated with 18F-FDG PET SUVR in both the left hippocampus and right amygdala. There were no associations observed between global cognition, delayed recall in logical memory, or visual reproduction and 18F-FDG PET SUVR. Following stratification of the cohort into subjective memory complainers and non-complainers, verbal logical memory immediate recall was positively associated with 18F-FDG PET SUVR in the right amygdala in those with subjective memory complaints. There were no significant associations observed in non-memory complainers between 18F-FDG PET SUVR in regions of interest and cognitive performance. We observed subjective memory complaint-specific associations between 18F-FDG PET SUVR and immediate verbal memory performance in our cohort, however found no associations between delayed recall of verbal memory performance or visual memory performance. It is here argued that the neural mechanisms underlying verbal and visual memory performance may in fact differ in their pathways, and the characteristic reduction of 18F-FDG PET SUVR observed in this and previous studies likely reflects the pathophysiological changes in specific

  14. Effect of postprandial hyperglycaemia in non-invasive measurement of cerebral metabolic rate of glucose in non-diabetic subjects

    Energy Technology Data Exchange (ETDEWEB)

    Tsuchida, Tatsuro; Itoh, Harumi [Department of Radiology, Fukui Medical University, Matsuoka (Japan); Sadato, Norihiro; Nishizawa, Sadahiko; Yonekura, Yoshiharu [Biomedical Imaging Research Center, Fukui Medical University (Japan)

    2002-02-01

    The aim of this study was to determine the effect of postprandial hyperglycaemia (HG) on the non-invasive measurement of cerebral metabolic rate of glucose (CMRGlc). Five patients who had a meal within an hour before a fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) examination were recruited in this study. They underwent intermittent arterial blood sampling (measured input function), and, based on this sampling, CMRGlc was calculated using an autoradiographic method (CMRGlc{sub real}). Simulated input functions were generated based on standardised input function, body surface area and net injected dose of FDG, and simulated CMRGlc (CMRGlc{sub sim}) was also calculated. Percent error of the area under the curve (AUC) between measured (AUC{sub real}) and simulated input function (AUC{sub IFsim}) and percent error between CMRGlc{sub real} and CMRGlc{sub sim} were calculated. These values were compared with those obtained from a previous study conducted under fasting conditions (F). The serum glucose level in the HG group was significantly higher than that in the F group (165{+-}69 vs 100{+-}9 mg/dl, P=0.0007). Percent errors of AUC and CMRGlc in grey matter and white matter in HG were significantly higher than those in F (12.9%{+-}1.3% vs 3.5%{+-}2.2% in AUC, P=0.0015; 18.2%{+-}2.2% vs 2.9%{+-}1.9% in CMRGlc in grey matter, P=0.0028; 24.0%{+-}4.6% vs 3.4%{+-}2.2% in CMRGlc in white matter, P=0.0028). It is concluded that a non-invasive method of measuring CMRGlc should be applied only in non-diabetic subjects under fasting conditions. (orig.)

  15. Atmospheric oxygen level affects growth trajectory, cardiopulmonary allometry and metabolic rate in the American alligator (Alligator mississippiensis)

    Science.gov (United States)

    Owerkowicz, Tomasz; Elsey, Ruth M.; Hicks, James W.

    2009-01-01

    Summary Recent palaeoatmospheric models suggest large-scale fluctuations in ambient oxygen level over the past 550 million years. To better understand how global hypoxia and hyperoxia might have affected the growth and physiology of contemporary vertebrates, we incubated eggs and raised hatchlings of the American alligator. Crocodilians are one of few vertebrate taxa that survived these global changes with distinctly conservative morphology. We maintained animals at 30°C under chronic hypoxia (12% O2), normoxia (21% O2) or hyperoxia (30% O2). At hatching, hypoxic animals were significantly smaller than their normoxic and hyperoxic siblings. Over the course of 3 months, post-hatching growth was fastest under hyperoxia and slowest under hypoxia. Hypoxia, but not hyperoxia, caused distinct scaling of major visceral organs–reduction of liver mass, enlargement of the heart and accelerated growth of lungs. When absorptive and post-absorptive metabolic rates were measured in juvenile alligators, the increase in oxygen consumption rate due to digestion/absorption of food was greatest in hyperoxic alligators and smallest in hypoxic ones. Hyperoxic alligators exhibited the lowest breathing rate and highest oxygen consumption per breath. We suggest that, despite compensatory cardiopulmonary remodelling, growth of hypoxic alligators is constrained by low atmospheric oxygen supply, which may limit their food utilisation capacity. Conversely, the combination of elevated metabolism and low cost of breathing in hyperoxic alligators allows for a greater proportion of metabolised energy to be available for growth. This suggests that growth and metabolic patterns of extinct vertebrates would have been significantly affected by changes in the atmospheric oxygen level. PMID:19376944

  16. Pyruvate modifies metabolic flux and nutrient sensing during extracorporeal membrane oxygenation in an immature swine model

    Energy Technology Data Exchange (ETDEWEB)

    Ledee, Dolena R.; Kajimoto, Masaki; O' Kelly-Priddy, Colleen M.; Olson, Aaron; Isern, Nancy G.; Robillard Frayne, Isabelle; Des Rosiers, Christine; Portman, Michael A.

    2015-07-01

    Extracorporeal membrane oxygenation (ECMO) provides mechanical circulatory support for infants and children with postoperative cardiopulmonary failure. Nutritional support is mandatory during ECMO, although specific actions for substrates on the heart have not been delineated. Prior work shows that enhancing pyruvate oxidation promotes successful weaning from ECMO. Accordingly, we closely examined the role of prolonged systemic pyruvate supplementation in modifying metabolic parameters during the unique conditions of ventricular unloading provided by ECMO. Twelve male mixed breed Yorkshire piglets (age 30-49 days) received systemic infusion of either normal saline (Group C) or pyruvate (Group P) during ECMO for 8 hours. Over the final hour piglets received [2-13C] pyruvate, and [13C6]-L-leucine, as an indicator for oxidation and protein synthesis. A significant increase in lactate and pyruvate concentrations occurred, along with an increase in the absolute concentration of all measured CAC intermediates. Group P showed greater anaplerotic flux through pyruvate carboxylation although pyruvate oxidation relative to citrate synthase flux was similar to Group C. The groups demonstrated similar leucine fractional contributions to acetyl-CoA and fractional protein synthesis rates. Pyruvate also promoted an increase in the phosphorylation state of several nutrient sensitive enzymes, such as AMPK and ACC, and promoted O-GlcNAcylation through the hexosamine biosynthetic pathway (HBP). In conclusion, prolonged pyruvate supplementation during ECMO modified anaplerotic pyruvate flux and elicited changes in important nutrient and energy sensitive pathways, while preserving protein synthesis. Therefore, the observed results support the further study of nutritional supplementation and its downstream effects on cardiac adaptation during ventricular unloading.

  17. High- and moderate-intensity aerobic exercise and excess post-exercise oxygen consumption in men with metabolic syndrome.

    Science.gov (United States)

    Larsen, I; Welde, B; Martins, C; Tjønna, A E

    2014-06-01

    Physical activity is central in prevention and treatment of metabolic syndrome. High-intensity aerobic exercise can induce larger energy expenditure per unit of time compared with moderate-intensity exercise. Furthermore, it may induce larger energy expenditure at post-exercise recovery. The aim of this study is to compare the excess post-exercise oxygen consumption (EPOC) in three different aerobic exercise sessions in men with metabolic syndrome. Seven men (age: 56.7 ± 10.8) with metabolic syndrome participated in this crossover study. The sessions consisted of one aerobic interval (1-AIT), four aerobic intervals (4-AIT), and 47-min continuous moderate exercise (CME) on separate days, with at least 48 h between each test day. Resting metabolic rate (RMR) was measured pre-exercise and used as baseline value. EPOC was measured until baseline metabolic rate was re-established. An increase in O2 uptake lasting for 70.4 ± 24.8 min (4-AIT), 35.9 ± 17.3 min (1-AIT), and 45.6 ± 17.3 min (CME) was observed. EPOC were 2.9 ± 1.7 L O2 (4-AIT), 1.3 ±  .1 L O2 (1-AIT), and 1.4 ± 1.1 L O2 (CME). There were significant differences (P EPOC was highest after 4-AIT. These data suggest that exercise intensity has a significant positive effect on EPOC in men with metabolic syndrome.

  18. Effect of fasudil combined with conventional therapy on nerve and blood coagulation function as well as Hcy metabolism in patients with acute cerebral infarction

    Institute of Scientific and Technical Information of China (English)

    Zhi-Yong Lu

    2017-01-01

    Objective:To analyze the effect of fasudil combined with conventional therapy on nerve and blood coagulation function as well as Hcy metabolism in patients with acute cerebral infarction. Methods:80 patients with acute cerebral infarction treated in our hospital between January 2013 and January 2013 were selected as the research subjects and divided into observation group (n = 40) and control group (n = 40) according to the random number table. Control group received conventional therapy and observation group received fasudil combined with conventional therapy. After 14 d of treatment, the levels of cerebral blood perfusion parameters, nerve function indexes, platelet function indexes and homocysteine (Hcy) of two groups of patients were determined.Results:After 14 d of treatment, middle cerebral artery and basilar artery peak systolic flow velocity (Vs), low diastolic flow velocity (Vd) and mean flow velocity (Vm) levels of observation group were higher than those of control group (P<0.05); serum nerve function indexes brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) content were higher than those of control group (P<0.05) while phosphatidic acid (PA), neuron-specific enolase (NSE), S100β protein (S100β), and substantia nigra divalent metal transporter 1 (DMT1) content were lower than those of control group (P<0.05); serum platelet function indexes platelet activation-dependent granule membrane protein-140 (GMP-140), fibrinogen receptor-1 (PAC-1), platelet activating factor (PAF) and platelet-derived growth factor BB (PDGF-BB) content were lower than those of control group (P<0.05); serum Hcy content was lower than that of control group (P<0.05).Conclusions:Fasudil combined with conventional therapy can optimize the nerve function and blood coagulation function in patients with acute cerebral infarction, and also plays a positive role in reducing Hcy levels.

  19. Improvement of oxygen supply by an artificial carrier in combination with normobaric oxygenation decreases the volume of tissue hypoxia and tissue damage from transient focal cerebral ischemia

    NARCIS (Netherlands)

    Seiffge, David J.; Lapina, Natalia E.; Tsagogiorgas, Charalambos; Theisinger, Bastian; Henning, Robert H.; Schilling, Lothar

    2012-01-01

    Tissue hypoxia may play an important role in the development of ischemic brain damage. In the present study we investigated in a rat model of transient focal brain ischemia the neuroprotective effects of increasing the blood oxygen transport capacity by applying a semifluorinated alkane (SFA)-contai

  20. Adult-onset hypothyroidism and the cerebral metabolism of (1,2-13C2) acetate as detected by 13C nuclear magnetic resonance.

    Science.gov (United States)

    Chapa, F; Künnecke, B; Calvo, R; Escobar del Rey, F; Morreale de Escobar, G; Cerdán, S

    1995-01-01

    The effects of adult-onset hypothyroidism on the metabolic compartmentation of the cerebral tricarboxylic acid cycle and the gamma-aminobutyric acid (GABA) shunt have been investigated by 13C nuclear magnetic resonance spectroscopy. Rats thyroidectomized as adults and age-matched controls were infused in the right jugular vein with unlabeled or (1,2-13C2) acetate solutions for 60 min. At the end of the infusion, the brains were frozen in situ and perchloric acid extracts were prepared and analyzed by 13C nuclear magnetic resonance and reverse-phase HPLC. Thyroidectomized animals showed a decrease in the incorporation of 13C from (1,2-13C2) acetate in cerebral metabolites and an increase in the concentrations of unlabeled glutamate and GABA. Computer-assisted interpretation of the 13C multiplets observed for the carbons of glutamate, glutamine, and GABA indicated that adult-onset hypothyroidism produced 1) a decrease in the contribution of infused (1,2-13C2) acetate to the glial tricarboxylic acid cycle; 2) an increase in the contribution of unlabeled acetyl-CoA to the neuronal tricarboxylic acid cycle; and 3) impairments in the exchange of glutamate, glutamine, and GABA between the neuronal and glial compartments. Despite the fact that the adult brain has often been considered metabolically unresponsive to thyroid hormone status, present results show metabolic alterations in the neuronal and glial compartments that are reversible with substitution therapy.

  1. FDG PET in non-pharmacological therapy in Alzheimer's disease; cerebral metabolic increase correlates with clinical improvement after cognitive therapy

    Energy Technology Data Exchange (ETDEWEB)

    Na, Hae Ri; Kim, Yu Kyeong; Park, Seong Min; Lee, Seung Hyun; Park, Eun Kyung; Lee, Jung Seok; Kim, Sang Yun; Kim, Sang Eun [Seoul National Univ. College of Medicine, Seoul (Korea, Republic of)

    2007-07-01

    In management of AD, pharmacological treatment alone using acetylcholinesterase inhibitor (AChEI) is general consensus, and provides beneficial effect to prolong their progression. Combined non-pharmacological therapy, especially cognitive therapy is recently having attention with expectation of improvement in cognitive ability. This study examined the effect of combined cognitive therapy in AD patients who were maintaining AChEI using FDG PET. Four patients (689 yrs) who diagnosed as probable Alzheimer's disease based on the NINCDS-ADRDA criteria participated in this study. 12-week cognitive therapy comprised seven fields to enhance orientation, memory, recall, visuo-motor organization, categorization and behavior modification/sequencing. They received 45-minute sessions twice per week with maintaining their previous medication. Clinical improvement was assessed by comprehensive neuropsychological tests. Two FDG PET studies were performed before cognitive therapy and in the middle of the therapy, and compared to evaluate the effect of cognitive therapy to cerebral metabolism. Two of 4 patients whose initial cognitive impairment was milder had clinical improvement after 12 weeks, the rest who were more severely impaired failed to have clinical improvement. Regional cerebral hypometabolism on initial PET was correlated with their functional status. Follow up PET of two responders demonstrated the increases in regional metabolism in the temporal and/or frontal cortex, which was associated their functional improvement. Cerebral metabolism in poor responders were minimally increased or no changed. This preliminary data suggests that cognitive therapy is potentially useful to stabilize or improve cognitive and functional performance in AD patients with relatively mild cognitive dysfunction. And FDG PET could demonstrate possible candidates for cognitive therapy and the effect of the therapy.

  2. 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

  3. Middle cerebral artery blood velocity and cerebral blood flow and O2 uptake during dynamic exercise

    DEFF Research Database (Denmark)

    Madsen, P L; Sperling, B K; Warming, T

    1993-01-01

    Results obtained by the 133Xe clearance method with external detectors and by transcranial Doppler sonography (TCD) suggest that dynamic exercise causes an increase of global average cerebral blood flow (CBF). These data are contradicted by earlier data obtained during less-well-defined conditions....... To investigate this controversy, we applied the Kety-Schmidt technique to measure the global average levels of CBF and cerebral metabolic rate of oxygen (CMRO2) during rest and dynamic exercise. Simultaneously with the determination of CBF and CMRO2, we used TCD to determine mean maximal flow velocity...... in the middle cerebral artery (MCA Vmean). For values of CBF and MCA Vmean a correction for an observed small drop in arterial PCO2 was carried out. Baseline values for global CBF and CMRO2 were 50.7 and 3.63 ml.100 g-1.min-1, respectively. The same values were found during dynamic exercise, whereas a 22% (P

  4. Voxel based statistical analysis method for microPET studies to assess the cerebral glucose metabolism in cat deafness model: comparison to ROI based method

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Su; Lee, Jae Sung; Park, Min Hyun; Lee, Jong Jin; Kang, Hye Jin; Lee, Hyo Jeong; Oh, Seung Ha; Kim, Chong Sun; Jung, June Key; Lee, Myung Chul; Lee, Dong Soo [Seoul National University College of Medicine, Seoul (Korea, Republic of); Lim, Sang Moo [KIRAMS, Seoul (Korea, Republic of)

    2005-07-01

    Imaging research on the brain of sensory-deprived cats using small animal PET scanner has gained interest since the abundant information about the sensory system of ths animal is available and close examination of the brain is possible due to larger size of its brain than mouse or rat. In this study, we have established the procedures for 3D voxel-based statistical analysis (SPM) of FDG PET image of cat brain, and confirmed using ROI based-method. FDG PET scans of 4 normal and 4 deaf cats were acquired for 30 minutes using microPET R4 scanner. Only the brain cortices were extracted using a masking and threshold method to facilitate spatial normalization. After spatial normalization and smoothing, 3D voxel-wise and ROI based t-test were performed to identify the regions with significant different FDG uptake between the normal and deaf cats. In ROI analysis, 26 ROIs were drawn on both hemispheres, and regional mean pixel value in each ROI was normalized to the global mean of the brain. Cat brains were spatially normalized well onto the target brain due to the removal of background activity. When cerebral glucose metabolism of deaf cats were compared to the normal controls after removing the effects of the global count, the glucose metabolism in the auditory cortex, head of caudate nucleus, and thalamus in both hemispheres of the deaf cats was significantly lower than that of the controls (P<0.01). No area showed a significantly increased metabolism in the deaf cats even in higher significance level (P<0.05). ROI analysis also showed significant reduction of glucose metabolism in the same region. This study established and confirmed a method for voxel-based analysis of animal PET data of cat brain, which showed high localization accuracy and specificity and was useful for examining the cerebral glucose metabolism in a cat cortical deafness model.

  5. Towards a neurobiology of dysfunctional arousal in depression: the relationship between beta EEG power and regional cerebral glucose metabolism during NREM sleep.

    Science.gov (United States)

    Nofzinger, E A; Price, J C; Meltzer, C C; Buysse, D J; Villemagne, V L; Miewald, J M; Sembrat, R C; Steppe, D A; Kupfer, D J

    2000-04-10

    This study sought to clarify the neurobiological basis of variations in one aspect of central nervous system 'arousal' in depression by characterizing the functional neuroanatomic correlates of beta electroencephalographic (EEG) power density during non-rapid eye movement (NREM) sleep. First, nine healthy (n=9) subjects underwent concurrent EEG sleep studies and [18F]2-fluoro-2-deoxy-D-glucose ([18F]FDG) positron emission tomography (PET) scans during their first NREM period of sleep in order to generate hypotheses about specific brain structures that show a relationship between increased beta power and increased relative glucose metabolism. Second, brain structures identified in the healthy subjects were then used as a priori regions of interest in similar analyses from identical studies in 12 depressed subjects. Statistical parametric mapping was used to identify the relationship between beta power and relative regional cerebral glucose metabolism (rCMRglu) during NREM sleep. Regions that demonstrated significant correlations between beta power and relative cerebral glucose metabolism in both the healthy and depressed subjects included the ventromedial prefrontal cortex and the right lateral inferior occipital cortex. During a baseline night of sleep, depressed patients demonstrated a trend toward greater beta power in relation to a separate age- and gender-matched healthy control group. In both healthy and depressed subjects, beta power negatively correlated with subjective sleep quality. Finally, in the depressed group, there was a trend for beta power to correlate with an indirect measure of absolute whole brain metabolism during NREM sleep. This study demonstrates a similar relationship between electrophysiological arousal and glucose metabolism in the ventromedial prefrontal cortex in depressed and healthy subjects. Given the increased electrophysiological arousal in some depressed patients and the known anatomical relations between the ventromedial

  6. Neuron-Specific Enolase Is Correlated to Compromised Cerebral Metabolism in Patients Suffering from Acute Bacterial Meningitis; An Observational Cohort Study

    DEFF Research Database (Denmark)

    Bartek, Jiri; Thelin, Eric Peter; Ghatan, Per Hamid;

    2016-01-01

    INTRODUCTION: Patients suffering from acute bacterial meningitis (ABM) with a decreased level of consciousness have been shown to have an improved clinical outcome if treated with an intracranial pressure (ICP) guided therapy. By using intracranial microdialysis (MD) to monitor cerebral metabolism......) guided therapy. Serum biomarkers were obtained at admission and every 12 hours. The MD parameters glucose, lactate, pyruvate and glycerol were analyzed. Outcome was assessed at 12-55 months after discharge from hospital. Mann-Whitney U-Test and Wilcoxon matched-pairs signed rank test were applied...

  7. Downstream signaling of reactive oxygen species, protein kinase C epsilon translocation and delayed neuroprotection in sevoflurane preconditioned rats following cerebral ischemia/reperfusion

    Institute of Scientific and Technical Information of China (English)

    Zhi Ye; Qulian Guo; E Wang; Yundan Pan; Qing Li; Honghao Zhou

    2009-01-01

    BACKGROUND: Brief exposure to the anesthetic sevoflurane results in delayed neuroprotection.However, few studies have addressed delayed neuroprotection after preconditioning with a single administration of sevoflurane.OBJECTIVE: To explore the relationship between a single preconditioning administration of sevoflurane and reactive oxygen species production and protein kinase C-epsilon (PKC- ε ) translocation.DESIGN, TIME, AND SETTING: The randomized, controlled, animal experiment was conducted at the Central Laboratory, Xiangya Hospital, Central South University, China from November 2007 to April 2008.MATERIALS: A total of 120 healthy, male, Sprague Dawley rats were equally and randomly assigned into five groups: sham operation, ischemia/reperfusion, sevoflurane, 2-mercaptopropionylglycine (2-MPG, a selective reactive oxygen species scavenger) + sevoflurane (MPG + sevoflurane), and MPG. Sevoflurane (Baxter, USA) and MPG (Sigma, USA) were used in this study.METHODS: Intervention consisted of three procedures. (1) MPG injection: a selective reactive oxygen species scavenger, MPG (20 mg/kg), was infused into the rat caudal vein in the MPG and MPG + sevoflurane groups. (2) Sevoflurane preconditioning: 30 minutes following MPG injection,rats in the sevoflurane and MPG + sevoflurane groups breathed a mixed gas of 2.4% sevoflurane and 97.6% oxygen for 60 minutes. Rats in the sham operation, ischemia/reperfusion, and MPG groups breathed 100% pure oxygen for 60 minutes. (3) Ischemia/reperfusion: 24 hours after sevoflurane or pure oxygen preconditioning, middle cerebral artery occlusion models were established in the ischemia/reperfusion, sevoflurane, MPG + sevoflurane, and MPG groups.Following 2 hours ischemia/6 hours and 24 hours reperfusion, the carotid artery was separated, but the middle cerebral artery was not occluded, in the sham operation group.MAIN OUTCOME MEASURES: In the ischemic hemisphere, PKC-ε translocation in the rat parietal cortex was measured by Western

  8. Reduction of reactive oxygen species ameliorates metabolism-secretion coupling in islets of diabetic GK rats by suppressing lactate overproduction.

    Science.gov (United States)

    Sasaki, Mayumi; Fujimoto, Shimpei; Sato, Yuichi; Nishi, Yuichi; Mukai, Eri; Yamano, Gen; Sato, Hiroki; Tahara, Yumiko; Ogura, Kasane; Nagashima, Kazuaki; Inagaki, Nobuya

    2013-06-01

    We previously demonstrated that impaired glucose-induced insulin secretion (IS) and ATP elevation in islets of Goto-Kakizaki (GK) rats, a nonobese model of diabetes, were significantly restored by 30-60-min suppression of endogenous reactive oxygen species (ROS) overproduction. In this study, we investigated the effect of a longer (12 h) suppression of ROS on metabolism-secretion coupling in β-cells by exposure to tempol, a superoxide (O2(-)) dismutase mimic, plus ebselen, a glutathione peroxidase mimic (TE treatment). In GK islets, both H2O2 and O2(-) were sufficiently reduced and glucose-induced IS and ATP elevation were improved by TE treatment. Glucose oxidation, an indicator of Krebs cycle velocity, also was improved by TE treatment at high glucose, whereas glucokinase activity, which determines glycolytic velocity, was not affected. Lactate production was markedly increased in GK islets, and TE treatment reduced lactate production and protein expression of lactate dehydrogenase and hypoxia-inducible factor 1α (HIF1α). These results indicate that the Warburg-like effect, which is characteristic of aerobic metabolism in cancer cells by which lactate is overproduced with reduced linking to mitochondria metabolism, plays an important role in impaired metabolism-secretion coupling in diabetic β-cells and suggest that ROS reduction can improve mitochondrial metabolism by suppressing lactate overproduction through the inhibition of HIF1α stabilization.

  9. Effects of nicardipine and nisoldipine on myocardial metabolism, coronary blood flow and oxygen supply in angina pectoris.

    Science.gov (United States)

    Rousseau, M F; Vincent, M F; Van Hoof, F; Van den Berghe, G; Charlier, A A; Pouleur, H

    1984-12-01

    The effects of the calcium antagonists nicardipine and nisoldipine on left ventricular (LV) metabolism were analyzed in 32 patients with angina pectoris. Measurements were made at a fixed heart rate under the basal state and during a cold pressor test (CPT). After administration of the drugs, coronary blood flow increased significantly and the mean aortic pressure decreased by 10% (p less than 0.01) in the basal state and by 11% (p less than 0.01) during CPT. Despite the reduction in pressure-rate product, myocardial oxygen consumption was unchanged in the basal state (18 +/- 4 vs 19 +/- 4 ml/min, difference not significant) and during CPT (21 +/- 5 vs 21 +/- 5 ml/min, difference not significant); this discrepancy between a reduced pressure-rate product and an unchanged oxygen consumption was also noted when nicardipine was given after propranolol (0.1 mg/kg; 12 patients). Both agents also increased LV lactate uptake, particularly during CPT (+13 mumol/min, p less than 0.05 vs control CPT) and reduced LV glutamine production. In 10 patients in whom 14C-lactate was infused, the chemical LV lactate extraction ratio increased more than the 14C-lactate extraction ratio after administration of the drugs, indicating a reduction in LV lactate production. The data are consistent with the hypothesis that nicardipine and nisoldipine improve perfusion and aerobic metabolism in chronically ischemic areas, resulting in an augmented oxygen consumption and in a reduced lactate production.

  10. Alterations in local cerebral glucose metabolism and endogenous thyrotropin-releasing hormone levels in rolling mouse Nagoya and effect of thyrotropin-releasing hormone tartrate.

    Science.gov (United States)

    Nakayama, T; Nagai, Y

    1996-11-01

    To identify the brain region(s) responsible for the expression of ataxic gaits in an ataxic mutant mouse model, Rolling mouse Nagoya (RMN), changes in local cerebral glucose metabolism in various brain regions and the effect of thyrotropin-releasing hormone tartrate (TRH-T), together with alterations in endogenous thyrotropin-releasing hormone (TRH) levels in the brains of RMN, were investigated. Ataxic mice [RMN (rol/rol)] showed significant decreases in glucose metabolism in regions of the diencephalon: thalamic dorsomedial nucleus, lateral geniculate body and superior colliculus; brain stem: substantia nigra, raphe nucleus and vestibular nucleus; and cerebellar nucleus as compared with normal controls [RMN (+/+)]. When RMN (rol/rol) was treated with TRH-T (10 mg/kg, equivalent to 7 mg/kg free TRH), glucose metabolism was significantly increased in these regions. These results suggest that these regions may be responsible for ataxia. We also found that TRH levels in the cerebellum and brain stem of RMN (rol/rol) were significantly higher than those of RMN (+/+). These results suggest that ataxic symptoms in RMN (rol/rol) may relate to the abnormal metabolism of TRH and energy metabolism in the cerebellum and/or brain stem and that exogenously given TRH normalizes them.

  11. 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

  12. Lidocaine Oxidation by Electrogenerated Reactive Oxygen Species in the Light of Oxidative Drug Metabolism

    NARCIS (Netherlands)

    Nouri-Nigjeh, Eslam; Permentier, Hjalmar P.; Bischoff, Rainer; Bruins, Andries P.

    2010-01-01

    The study of oxidative drug metabolism by Cytochrome P450s (P450) is important in the earlier stages of drug development. For this purpose, automated analytical techniques are needed for fast and accurate estimation of oxidative drug metabolism. Previous studies have shown that electrochemistry in c

  13. Kinetic and metabolic considerations in the use of (I-125) HIPDM as a tracer for quantitative measurement of regional cerebral blood flow

    Energy Technology Data Exchange (ETDEWEB)

    Lucignani, G.; Nehlig, A.; Blasberg, R.; Patlak, C.S.; Anderson, L.; Kung, H.F.; Fieschi, C.; Fazio, F.; Sokoloff, L.

    1984-01-01

    The kinetics of cerebral uptake and the metabolism of radioactive iodine labeled HIPDM (N,N,N'-trimethyl-N'-(2-hydroxy-3-methyl-5-(I-125)iodobenzyl) -1,3-propanediamine)(I-125)HIPDM were studied in vivo in male adult Sprague-Dawley rats in order to evaluate the potential usefulness of this compound for quantitative measurement of regional cerebral blood flow (rCBF). The first pass extraction fraction of (I-125)HIPDM in brain was found to be about 80%. The arterial concentration of unmetabolized (I-125)HIPDM following an i.v. pulse drops rapidly and represents only 30% of the blood sample total radioactivity at 60 minutes, whereas 92% of the radioactivity in brain tissue at the same time is in unaltered (I-125)HIPDM. The rate constant for (I-125)HIPDM transport across the blood-brain barrier (BBB) was calculated on the basis of a distribution model in which bi-directional exchange of the tracer between brain tissue and vascular space is assumed. A kinetic model and an operational equation have been derived for determination of rCBF with this molecule. The model and equation take into account the three following factors: (a) incomplete first pass extraction; (b) HIPDM metabolism; (c) bi-directional flux of tracer across the BBB. The observations suggest that this molecule might be of potential usefulness for rCBF measurements with single photon emission tomography, provided that all these factors are evaluated in man.

  14. Metabolic physiology of the Humboldt squid, Dosidicus gigas: Implications for vertical migration in a pronounced oxygen minimum zone

    Science.gov (United States)

    Rosa, Rui; Seibel, Brad A.

    2010-07-01

    The Humboldt (or jumbo) squid, Dosidicus gigas, is an active predator endemic to the Eastern Pacific that undergoes diel vertical migrations into a pronounced oxygen minimum layer (OML). Here, we investigate the physiological mechanisms that facilitate these migrations and assess the associated costs and benefits. Exposure to hypoxic conditions equivalent to those found in the OML (∼10 μM O 2 at 10 °C) led to a significant reduction in the squid’s routine metabolic rate (RMR), from 8.9 to 1.6 μmol O 2 g -1 h -1 ( p gigas may repay any oxygen debt accumulated during the daytime. The dive to deeper water may minimize exposure to stressful surface temperatures when most prey have migrated to depth during the daytime. The physiological and ecological strategies demonstrated here may have facilitated the recent range expansion of this species into northern waters where expanding hypoxic zones prohibit competing top predators.

  15. Blood-Oxygenation-Level-Dependent-(BOLD- Based R2′ MRI Study in Monkey Model of Reversible Middle Cerebral Artery Occlusion

    Directory of Open Access Journals (Sweden)

    Jing Zhang

    2011-01-01

    Full Text Available Objective. To investigate the value of BOLD-based reversible transverse relaxation rate (R2′ MRI in detecting ischemic penumbra (IP in a monkey model of reversible middle cerebral artery occlusion (MCAO and time evolution of relative R2′ (rR2′ in infarcted core, IP, and oligemia. Materials and Methods. 6 monkeys were used to make MCAO by the microcatheter method. MR scans were performed at 0 h (1 h after MCAO, 1 h, 3 h, 6 h, 12 h, 24 h, and 48 h after reperfusion. R2′ was calculated using quantitative T2 and T2∗ maps. Ischemic area was subdivided into infracted core, IP and oligemia. rR2′ was calculated respectively. Results. Reversible MCAO model for 4/6 monkeys was made successfully. rR2′ values were significantly different at each time point, being highest in oligemia followed by IP and infarcted core (<.05. With reperfusion time evolution, rR2′ in infarcted core showed a decreased trend: sharply decreased within 6 hours and maintained at 0 during 6–48 hours (<.05. rR2′ values in IP and oligemia showed similar increased trend: sharply increased within 6 hours, maintained a plateau during 6–24 hours, and slightly increased until 48 hours. Conclusion. BOLD-based R2′ MRI can be used to describe changes of cerebral oxygen extract in acute ischemic stroke, and it can provide additional information in detecting IP. The time evolution rR2′ in infarcted core, IP, and oligemia is in accordance with the underlying pathophysiology.

  16. Comparison on the influence of different anesthesia methods for oxygen metabolism and hemodynamics of patients with infective shock

    Institute of Scientific and Technical Information of China (English)

    Ma Jie

    2016-01-01

    Objective:To observe and compare the influence state of general anesthesia and general anesthesia combined with epidural anesthesia for the oxygen metabolism and hemodynamics of patients with infective shock, in order to provide evidence for the selection of anesthesia methods of the patients with infective shock.Methods:A total of 42 patients with infective shock in hospital from April 2013 to December 2015 were randomly divided into control group and observation group by the principle of random allocation, 21 cases in control group were with general anesthesia, 21 cases in observation group were with general anesthesia integrated with epidural anesthesia, then the oxygen metabolism and hemodynamics indexes of two groups before the anesthesia and at 20min during the operation, at 10min after the operation were compared.Results: The oxygen metabolism parameters including SvO2, CjvO2 and VO2 were respectively (64.81±5.99)%, (94.24±5.32) mL/L, (136.16±8.32) mL/min•m2 and (67.20±6.08)%, (95.10±5.40) mL/L, (133.15±8.17) mL/min•m2, and they were all better than (60.11±5.81)%, (90.11±5.04) mL/L, (145.15±9.38) mL/min•m2 and (63.24±5.95)%, (92.23±5.18) mL/L, (142.24±9.11) mL/min•m2 of control group, the hemodynamics indexes were all better than those of control group.Conclusion: The influence state of general anesthesia integrated with epidural anesthesia or the oxygen metabolism and hemodynamics of patients with infective shock are better than those of general anesthesia, so the application value of general anesthesia integrated with epidural anesthesia in the patients are relatively higher.

  17. 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

    sweling in rats after middle cerebral artery occlusion, and discuss the possible mechanism of action underlying the neuroprotective effects of hyperbaric oxygen therapy in rats with cerebral infraction. METHODS:Sixty adult female rat models of cerebral infarction were successfuly established by middle cerebral artery occlusion using suture method and then randomly divided into the sham, cerebral infarction and hyperbaric oxygen therapy groups (n=20 rats/group). At 3 days after middle cerebral artery occlusion, apoptosis of nerve cels in the infract area of rats in each group was detected by TUNEL method. At 72 hours after middle cerebral artery occlusion, the gene transcription and protein expression of aquaporin 4/9 and matrix metaloproteinases 9/2 in the peri-infarct area were detected by RT-PCR and western blot analysis. The pathomorphological change in the infract area was observed by hematoxylin-eosin staining. The expression level of glial fibrilary acidic protein was detected by immunohistochemistry. At 24 hours and 3 days after hyperbaric oxygen therapy and at 1 and 2 weeks after middle cerebral artery occlusion, neurological behaviors were evaluated using Longa behavioral scores. RESULTS AND CONCLUSION:After 1, 2 days of hyperbaric oxygen therapy, Longa behavioral scores in the hyperbaric oxygen therapy group were significantly lower than those in the cerebral infarction group (P < 0.05). At 3 days after middle cerebral artery occlusion, cel apoptosis index in the hyperbaric oxygen therapy group was significantly lower than that in the cerebral infarction group (P < 0.05). At 72 hours after middle cerebral artery occlusion, the aquaporin 4/9, matrix metaloproteinases 9/2 gene and protein expression in the hyperbaric oxygen group were significantly lower than those in the cerebral infarction group (P < 0.05). These results suggest that hyperbaric oxygen therapy can play its protective role by decreasing apoptosis of nerve cels in the infarct area and lessening

  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. Strategies for improving the Voxel-based statistical analysis for animal PET studies: assessment of cerebral glucose metabolism in cat deafness model

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Su; Lee, Jae Sung; Park, Min Hyun; Kang, Hye Jin; Im, Ki Chun; Moon, Dae Hyuk; Lim, Sang Moo; Oh, Seung Ha; Lee, Dong Soo [Seoul National Univ. College of Medicine, Seoul (Korea, Republic of)

    2007-07-01

    In imaging studies of the human brain, voxel-based statistical analysis method was widely used, since these methods were originally developed for the analysis of the human brain data, they are not optimal for the animal brain data. The aim of this study is to optimize the procedures for the 3D voxel-based statistical analysis of cat FDG PET brain images. A microPET Focus 120 scanner was used. Eight cats underwent FDG PET scans twice before and after inducing the deafness. Only the brain and adjacent regions were extracted from each data set by manual masking. Individual PET image at normal and deaf state was realigned to each other to remove the confounding effects by the different spatial normalization parameters on the results of statistical analyses. Distance between the sampling points on the reference image and kernel size of Gaussian filter applied to the images before estimating the realignment parameters were adjusted to 0.5 mm and 2 mm. Both data was then spatial normalized onto study-specific cat brain template. Spatially normalized PET data were smoothed and voxel-based paired t-test was performed. Cerebral glucose metabolism decreased significantly after the loss of hearing capability in parietal lobes, postcentral gyri, STG, MTG, lTG, and IC at both hemisphere and left SC (FDR corrected P < 0.05, k=50). Cerebral glucose metabolism in deaf cats was found to be significantly higher than in controls in the right cingulate (FDR corrected P < 0.05, k=50). The ROI analysis also showed significant reduction of glucose metabolism in the same areas as in the SPM analysis, except for some regions (P < 0.05). Method for the voxel-based analysis of cat brain PET data was optimized for analysis of cat brain PET. This result was also confirmed by ROI analysis. The results obtained demonstrated the high localization accuracy and specificity of the developed method, and were found to be useful for examining cerebral glucose metabolism in a cat cortical deafness model.

  20. Expensive cerebral blood flow measurements alone are useless and misinformative in comatose patients: a comprehensive alternative Medidas dispendiosas apenas de fluxo sanguíneo cerebral são inúteis e desinformativas em estados de coma: uma alternativa abrangente

    Directory of Open Access Journals (Sweden)

    Julio Cruz

    2003-06-01

    Full Text Available Since the first report addressing quantification of cerebral blood flow (CBF, concomitant assessment of cerebral oxygen consumption was also carried out. Over the years, however, some investigators have emphatically and mistakenly addressed cerebral ischemia in comatose patients, on the basis of CBF measurements alone. In contrast, we have repeatedly reported that ischemia in these patients must be precisely evaluated based on CBF-metabolism coupling or uncoupling, rather than CBF alone. Based on these previous findings, we therefore propose a comprehensive alternative approach, namely the evaluation of brain ischemia in comatose patients based on cerebral metabolic parameters, such as cerebral extraction of oxygen or cerebral lactate release, without expensive CBF measurements.Desde o primeiro artigo apresentando quantificação de fluxo sanguíneo cerebral (FSC, também se avaliou o consumo cerebral de oxigênio. Todavia, ao longo dos anos, alguns investigadores têm enfaticamente e erroneamente destacado a isquemia cerebral em pacientes comatosos, baseando-se apenas em medidas do FSC. Em contrapartida, temos repetidamente destacado que a avaliação de isquemia cerebral nestes pacientes deve ser baseada no conceito de acoplamento ou desacoplamento entre metabolismo cerebral e FSC, ao invés de alterações no FSC apenas. Baseando-se nestes achados prévios, aqui propomos uma abordagem alternativa e abrangente, a qual envolve a avaliação de isquemia cerebral em pacientes comatosos baseando-se em parâmetros metabólicos cerebrais, tais como a extração cerebral de oxigênio ou a liberação cerebral de lactato, sem medidas dispendiosas de FSC.

  1. Cerebral glucose metabolism in long-term survivors of childhood primary brain tumors treated with surgery and radiotherapy

    DEFF Research Database (Denmark)

    Andersen, Preben B.; Krabbe, Katja; Leffers, Anne M.

    2003-01-01

    a median recurrence free survival of 16 years by MRI and Positron Emission Tomography using the glucose analog 2-18F-fluoro-2-deoxy-D-glucose (18FDG). Three patients were not analyzed further due to diffuse cerebral atrophy, which might be related to previous hydrocephalus. Twenty-one patients were...

  2. Contributions to elevated metabolism during recovery: dissecting the excess postexercise oxygen consumption (EPOC) in the desert iguana (Dipsosaurus dorsalis).

    Science.gov (United States)

    Hancock, Thomas V; Gleeson, Todd T

    2008-01-01

    The excess postexercise oxygen consumption (EPOC), a measure of recovery costs, is known to be large in ectothermic vertebrates such as the desert iguana (Dipsosaurus dorsalis), especially after vigorous activity. To analyze the cause of these large recovery costs in a terrestrial ectotherm, Dipsosaurus were run for 15 s at maximal-intensity (distance 35.0+/-1.9 m; 2.33+/-0.13 m s(-1)) while O(2) uptake was monitored via open-flow respirometry. Muscle metabolites (adenylates, phosphocreatine, and lactate) were measured at rest and after 0, 3, 10, and 60 min of recovery. Cardiac and ventilatory activity during rest and recovery were measured, as were whole-body lactate and blood lactate, which were used to estimate total muscle activity. This vigorous activity was supported primarily by glycolysis (65%) and phosphocreatine hydrolysis (29%), with only a small contribution from aerobic metabolism (2.5%). Aerobic recovery lasted 43.8+/-4.6 min, and EPOC measured 0.166+/-0.025 mL O(2) g(-1). This was a large proportion (98%) of the total suprabasal metabolic cost of the activity to the animal. The various contributions to EPOC after this short but vigorous activity were quantified, and a majority of EPOC was accounted for. The two primary causes of EPOC were phosphocreatine repletion (32%-50%) and lactate glycogenesis (30%-47%). Four other components played smaller roles: ATP repletion (8%-13%), elevated ventilatory activity (2%), elevated cardiac activity (2%), and oxygen store resaturation (1%).

  3. Effect of Glomus versiforme inoculation on reactive oxygen metabolism of Citrus tangerine leaves exposed to water stress

    Institute of Scientific and Technical Information of China (English)

    WU Qiangsheng; ZOU Yingning; XIA Renxue

    2007-01-01

    In a potted greenhouse experiment,Citrus tangerine Hort.ex Tanaka was inoculated with arbuscular mycorrhizal (AM) fungus,Glomus versiforme (Karsten)Berch,or non-AM fungus as control.Arbuscular mycorrhizal and non-AM seedlings were grown tmder well-watered or water-stressed conditions after 97 days of acclimation.The reactive oxygen metabolism of C.tangerine leaves was studied in order to elucidate whether AM symbiosis affects enzymatic and non-enzymatic antioxidants.The results showed that water stress caused a decrement of 33% for the colonization of G.versiforme on C.tangerine roots.Under well-watered and water-stressed conditions,G.versiforme inoculation increased the leaf phosphorus (P) content by 45% and 27%,and decreased the leaf malondialdehyde and hydrogen peroxide contents by 25% and 21%,and 16% and 16%,respectively,compared with the control.Inoculation with G.versiforme enhanced the activities of leaf superoxide dismutase,peroxidase,catalase and ascorbate peroxidase,and increased the contents of leaf soluble protein,ascorbate and total ascorbate notably,regardless of soil moisture conditions.Under water-stressed conditions,G.versiforme inoculation decreased the leaf superoxide anion radical (O2-) content by 31%.It is concluded that drought resistance of C.tangerine leaves is enhanced due to the improvement of reactive oxygen metabolism after G.versiforme inoculation.

  4. The metabolic response of pteropods to acidification reflects natural CO2-exposure in oxygen minimum zones

    Directory of Open Access Journals (Sweden)

    K. F. Wishner

    2012-02-01

    Full Text Available Shelled pteropods (Thecosomata are a group of holoplanktonic mollusks that are believed to be especially sensitive to ocean acidification because their aragonitic shells are highly soluble. Despite this concern, there is very little known about the physiological response of these animals to conditions of elevated carbon dioxide. This study examines the oxygen consumption and ammonia excretion of five pteropod species, collected from tropical regions of the Pacific Ocean, to elevated levels of carbon dioxide (0.10%, 1000 ppm. Our results show that pteropods that naturally migrate into oxygen minimum zones, such as Hyalocylis striata, Clio pyramidata, Cavolinia longirostris and Creseis virgula, were not affected by carbon dioxide at the levels and duration tested. Diacria quadridentata, which does not migrate, responds to high carbon dioxide conditions with reduced oxygen consumption and ammonia excretion. This indicates that the natural chemical environment of individual species may influence their resilience to ocean acidification.

  5. Metabolic encephalopathies.

    Science.gov (United States)

    Angel, Michael J; Young, G Bryan

    2011-11-01

    Kinnier Wilson coined the term metabolic encephalopathy to describe a clinical state of global cerebral dysfunction induced by systemic stress that can vary in clinical presentation from mild executive dysfunction to deep coma with decerebrate posturing; the causes are numerous. Some mechanisms by which cerebral dysfunction occurs in metabolic encephalopathies include focal or global cerebral edema, alterations in transmitter function, the accumulation of uncleared toxic metabolites, postcapillary venule vasogenic edema, and energy failure. This article focuses on common causes of metabolic encephalopathy, and reviews common causes, clinical presentations and, where relevant, management.

  6. Effect of exercise training on eNOS expression, NO production and oxygen metabolism in human placenta.

    Directory of Open Access Journals (Sweden)

    Robinson Ramírez-Vélez

    Full Text Available OBJECTIVE: To determine the effects of combined aerobic and resistance exercise training during the second half of pregnancy on endothelial NOS expression (eNOS, nitric oxide (NO production and oxygen metabolism in human placenta. METHODS: The study included 20 nulliparous in gestational week 16-20, attending prenatal care at three tertiary hospitals in Colombia who were randomly assigned into one of two groups: The exercise group (n = 10 took part in an exercise session three times a week for 12 weeks which consisted of: aerobic exercise at an intensity of 55-75% of their maximum heart rate for 60 min and 25 mins. Resistance exercise included 5 exercise groups circuit training (50 repetitions of each using barbells (1-3 kg/exercise and low-to-medium resistance bands. The control group (n = 10 undertook their usual physical activity. Mitochondrial and cytosol fractions were isolated from human placental tissue by differential centrifugation. A spectrophotometric assay was used to measure NO production in cytosolic samples from placental tissue and Western Blot technique to determine eNOS expression. Mitochondrial superoxide levels and hydrogen peroxide were measured to determine oxygen metabolism. RESULTS: Combined aerobic and resistance exercise training during pregnancy leads to a 2-fold increase in eNOS expression and 4-fold increase in NO production in placental cytosol (p = 0.05. Mitochondrial superoxide levels and hydrogen peroxide production rate were decreased by 8% and 37% respectively in the placental mitochondria of exercising women (p = 0.05. CONCLUSION: Regular exercise training during the second half of pregnancy increases eNOS expression and NO production and decreases reactive oxygen species generation in human placenta. Collectively, these data demonstrate that chronic exercise increases eNOS/NO production, presumably by increasing endothelial shear stress. This adaptation may contribute to the beneficial effects of exercise on

  7. Enhanced metabolic versatility of planktonic sulfur-oxidizing γ-proteobacteria in an oxygen-deficient coastal ecosystem

    Directory of Open Access Journals (Sweden)

    Alejandro A. Murillo

    2014-07-01

    Full Text Available Sulfur-oxidizing Gamma-proteobacteria are abundant in marine oxygen-deficient waters, and appear to play a key role in a previously unrecognized cryptic sulfur cycle. Metagenomic analyses of members of the uncultured SUP05 lineage in the Canadian seasonally anoxic fjord Saanich Inlet (SI, hydrothermal plumes in the Guaymas Basin (GB and single cell genomics analysis of two ARCTIC96BD-19 representatives from the South Atlantic Sub-Tropical Gyre (SASG have shown them to be metabolically versatile. However, SI and GB SUP05 bacteria seem to be obligate chemolithoautotrophs, whereas ARCTIC96BD-19 has the genetic potential for aerobic respiration. Here, we present results of a metagenomic analysis of sulfur-oxidizing Gamma-proteobacteria (GSO, closely related to the SUP05/ARCTIC96BD-19 clade, from a coastal ecosystem in the eastern South Pacific (ESP. This ecosystem experiences seasonal anoxia and accumulation of nitrite and ammonium at depth, with a corresponding increase in the abundance of GSO representatives. The ESP-GSOs appear to have a significantly different gene complement than those from Saanich Inlet, Guaymas Basin and SASG. Genomic analyses of de novo assembled contigs indicate the presence of a complete aerobic respiratory complex based on the cytochrome bc1 oxidase. Furthermore, they appear to encode a complete TCA cycle and several transporters for dissolved organic carbon species, suggesting a mixotrophic lifestyle. Thus, the success of sulfur-oxidizing Gamma-proteobacteria in oxygen-deficient marine ecosystems appears due not only to their previously recognized anaerobic metabolic versatility, but also to their capacity to function under aerobic conditions using different carbon sources. Finally, members of ESP-GSO cluster also have the genetic potential for reducing nitrate to ammonium based on the nirBD genes, and may therefore facilitate a tighter coupling of the nitrogen and sulfur cycles in oxygen-deficient waters.

  8. [Effect of reduced oxygen concentrations and hydrogen sulfide on the amino acid metabolism and mesenchymal cells proliferation].

    Science.gov (United States)

    Plotnikova, L N; Berezovskii, V A; Veselskii, S P

    2015-01-01

    We investigated the effect of hydrogen sulfide donor (10(-12) mol/l NaHS--I group) alone and together with the reduced oxygen concentrations (5% O2--II group, 3% O2--III group, 24 h) on the biological processes of human stem cells culture. It was shown that the cells proliferation by the third day of cultivation in I, II and III group decreased 1,7; 2,8 and 4,2 times. On the 4th day of culture proliferation inhibited in I, II and III group by 29; 33 and 54% compared to the control. Thus, adverse effects NaHS enhanced by reducing the oxygen concentration. It was established that in all experimental versions rapidly absorbed from the culture medium amino acids: cysteine and cystine, serine and aspartic acid, valine and tryptophan, proline and hydroxyproline, which are involved in the synthesis of proteins, in particular collagen. In the culture medium increased the concentration of free amino acids of the three factions: arginine, histidine and taurine; glycine and methionine; alanine and glutamine. We believe that in the applied concentration of hydrogen sulfide donor in conditions of low oxygen in a gaseous medium incubation inhibits the proliferation and alters the amino acid metabolism of human cells line 4BL.

  9. Mental stress and cognitive performance do not increase overall level of cerebral O2 uptake in humans

    DEFF Research Database (Denmark)

    Madsen, P L; Schmidt, J F; Holm, S;

    1992-01-01

    We measured cerebral metabolic rate of oxygen (CMRO2), cerebral blood flow (CBF), and cerebral lactate output during rest, during the execution of mental arithmetic, and during mental stress induced by physical and psychological annoyance. Measurements were performed in healthy volunteers by use...... of the Kety-Schmidt technique with 133Xe as the inert gas. Electroencephalographic desynchronization and highly significant increases in plasma catecholamines and heart rate verified that the test measurements were performed during conditions differing distinctly from the resting state. In accordance...

  10. Rate of change in cerebral oxygenation and blood pressure in response to passive changes in posture: a comparison between pure autonomic failure patients and controls.

    Science.gov (United States)

    Tachtsidis, Ilias; Elwell, Clare E; Leung, Terence S; Bleasdale-Barr, Katharine; Hunt, Katharine; Toms, Nathan; Smith, Martin; Mathias, Christopher J; Delpy, David T

    2005-01-01

    The cardiovascular and cerebrovascular responses to head-up postural cha