WorldWideScience

Sample records for cerebral blood vessels

  1. Modeling the Role of the Glymphatic Pathway and Cerebral Blood Vessel Properties in Alzheimer's Disease Pathogenesis.

    Directory of Open Access Journals (Sweden)

    Christina Rose Kyrtsos

    Full Text Available Alzheimer's disease (AD is the most common cause of dementia in the elderly, affecting over 10% population over the age of 65 years. Clinically, AD is described by the symptom set of short term memory loss and cognitive decline, changes in mentation and behavior, and eventually long-term memory deficit as the disease progresses. On imaging studies, significant atrophy with subsequent increase in ventricular volume have been observed. Pathology on post-mortem brain specimens demonstrates the classic findings of increased beta amyloid (Aβ deposition and the presence of neurofibrillary tangles (NFTs within affected neurons. Neuroinflammation, dysregulation of blood-brain barrier transport and clearance, deposition of Aβ in cerebral blood vessels, vascular risk factors such as atherosclerosis and diabetes, and the presence of the apolipoprotein E4 allele have all been identified as playing possible roles in AD pathogenesis. Recent research has demonstrated the importance of the glymphatic system in the clearance of Aβ from the brain via the perivascular space surrounding cerebral blood vessels. Given the variety of hypotheses that have been proposed for AD pathogenesis, an interconnected, multilayer model offers a unique opportunity to combine these ideas into a single unifying model. Results of this model demonstrate the importance of vessel stiffness and heart rate in maintaining adequate clearance of Aβ from the brain.

  2. What is cerebral small vessel disease?

    International Nuclear Information System (INIS)

    An accumulating amount of evidence suggests that the white matter hyperintensities on T2 weighted brain magnetic resonance imaging predict an increased risk of dementia and gait disturbance. This state has been proposed as cerebral small vessel disease, including leukoaraiosis, Binswanger's disease, lacunar stroke and cerebral microbleeds. However, the concept of cerebral small vessel disease is still obscure. To understand the cerebral small vessel disease, the precise structure and function of cerebral small vessels must be clarified. Cerebral small vessels include several different arteries which have different anatomical structures and functions. Important functions of the cerebral small vessels are blood-brain barrier and perivasucular drainage of interstitial fluid from the brain parenchyma. Cerebral capillaries and glial endfeet, take an important role for these functions. However, the previous pathological investigations on cerebral small vessels have focused on larger arteries than capillaries. Therefore little is known about the pathology of capillaries in small vessel disease. The recent discoveries of genes which cause the cerebral small vessel disease indicate that the cerebral small vessel diseases are caused by a distinct molecular mechanism. One of the pathological findings in hereditary cerebral small vessel disease is the loss of smooth muscle cells, which is an also well-recognized finding in sporadic cerebral small vessel disease. Since pericytes have similar character with the smooth muscle cells, the pericytes should be investigated in these disorders. In addition, the loss of smooth muscle cells may result in dysfunction of drainage of interstitial fluid from capillaries. The precise correlation between the loss of smooth muscle cells and white matter disease is still unknown. However, the function that is specific to cerebral small vessel may be associated with the pathogenesis of cerebral small vessel disease. (author)

  3. Functional photoacoustic micro-imaging of cerebral hemodynamic changes in single blood vessels after photo-induced brain stroke

    Science.gov (United States)

    Liao, Lun-De; Chen, You-Yin; Lin, Chin-Teng; Li, Meng-Lin

    2013-03-01

    Studying the functional hemodynamic roles of individual cerebral cortical arterioles in maintaining both the structure and function of cortical regions during and after brain stroke in small animals is an important issue. Recently, functional photoacoustic microscopy (fPAM) has been proved as a reliable imaging technique to probe the total hemoglobin concentration (HbT), cerebral blood volume (CBV) and hemoglobin oxygen saturation (SO2) in single cerebral blood vessels of rats. Here, we report the application of fPAM associated with electrophysiology recordings to investigating functional hemodynamic changes in single cortical arterioles of rats with electrical forepaw stimulation after photo-induced ischemic stroke. Because of the weak optical focusing nature of our fPAM system, photo-induced ischemic stroke targeting single cortical arterioles can be easily conducted with simple adaptation. Functional HbT, CBV and SO2 changes associated with the induced stroke in selected arterioles from the anterior cerebral artery system were imaged with 36 x 65-μm spatial resolution. Experimental results showed that after photo-occlusion of a single arteriole, the functional changes of nearby arterioles in cerebral cortex only can be observed immediately after the stroke. After a few minutes of stroke onset, there are no significant functional changes under the forepaw stimulation, suggesting that alternate blood flow routes are not actively recruited. The fPAM with electrophysiology recordings complements existing imaging techniques and has the potential to offer a favorable tool for explicitly studying cerebral hemodynamics in small animal models of photo-indcued ischemic stroke.

  4. Computer-assisted spatial reconstruction of cerebral blood vessels and intracranial aneurysms

    Directory of Open Access Journals (Sweden)

    Nikolić Igor M.

    2006-01-01

    Full Text Available Introduction. Today, many medical procedures are based on image analysis with the aim of providing accurate diagnosis and optimal treatment. The goal of this report was to present clinical implications of computer-assisted geometric design of carotid aneurysms. Material and methods. In this study, the three-dimensional reconstruction was based on the approximation power of the parametric spline function, which achieves interpolation and surface fitting of the arterial information obtained by conventional angiography. Two views of conventional angiograms (anterioposterior and lateral views were used with a personal computer and commercial software. Results. This method of three-dimensional generated images was applied in 45 cases of cerebral aneurysms in carotid bifurcation. 3D reconstructions were made in approximately 20 minutes. They contributed to assessing vascular structures, and it was possible to rotate the three-dimensional image in different angles. Conclusion. Three-dimensional reconstruction of cerebral vessels is very useful for discussing surgical strategies preoperatively. Furthermore, it could also be used in endovascular procedures. .

  5. Real-time intraoperative full-range complex FD-OCT guided cerebral blood vessel identification and brain tumor resection in neurosurgery

    Science.gov (United States)

    Zhang, Kang; Huang, Yong; Pradilla, Gustavo; Tyler, Betty; Kang, Jin U.

    2011-03-01

    This work utilized an ultra-high-speed full-range complex-conjugate-free optical coherence tomography (FD-OCT) system to perform real-time intraoperative imaging to guide two common neurosurgical procedures: the cerebral blood vessel identification and the brain tumor resection. The cerebral blood vessel identification experiment is conducted ex vivo on human cadaver specimen. Specific cerebral arteries and veins in different positions of the specimen are visualized and the spatial relations between adjacent vessels are indentified through real-time 3D visualization. The brain tumor resection experiment is conducted in vivo on 9L gliomas established in rat brains. The normal brain-tumor margin can be clearly identified in depth of the tissue from sagittal, coronal and axial slices of the intraoperatively acquired 3D data set. The real-time full-range FD-OCT guided in vivo rat flank tumor resection is also conducted.

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

    International Nuclear Information System (INIS)

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

  7. Examining blood vessels

    International Nuclear Information System (INIS)

    This patent specification relates to an invention concerned with improvements in or relating to the examination of blood vessels of interest. Particles of dimensions not greater than 8 microns capable of providing detectable signals, are introduced into the blood for examination of a blood vessel. The particles may be sources of radiation, e.g. Ga68. (author)

  8. MAPK and pro-inflammatory mediators in the walls of brain blood vessels following cerebral ischemia

    OpenAIRE

    Maddahi, Aida

    2012-01-01

    INTRODUCTION Stroke is a serious neurological disease which may lead to death and severe disability [1, 2]. There are two major types of stroke: ischemic and hemorrhagic stroke. Both are associated with disruption of blood flow to a part of the brain with rapid depletion of cellular energy and oxygen, resulting in ionic disturbances and eventually neuronal cell death [3]. The pathologic process that develops after stroke is divided into acute (within hours), sub-acute (hours to days), ...

  9. Three-dimensional Gd-DTPA MR angiography of cerebral blood vessels

    International Nuclear Information System (INIS)

    Subtraction angiography based on three-dimensional fast MR imaging techniques using rephasing and dephasing gradient pulses is widely used. Similar angiograms can be obtained with three-dimensional gradient techniques before and after the administration of Gd-DTPA followed by imaging subtraction. As Gd-DTPA does not penetrate the blood-brain barrier, it does not alter brain images. Measurements were carried out in 14 patients with a 1.0-T whole-body imager (Siemens, Magnetom). Gd-DTPA angiography was superior to rephased-dephased angiography because of the higher signal intensity, lower noise due to short echo times, and high contrast for moving spins caused by Gd-DTPA

  10. Thiazine Red(+) platelet inclusions in Cerebral Blood Vessels are first signs in an Alzheimer's Disease mouse model.

    Science.gov (United States)

    Kniewallner, Kathrin M; Wenzel, Daniela; Humpel, Christian

    2016-01-01

    Strong evidence shows an association between cerebral vascular diseases and Alzheimer´s disease (AD). In order to study the interaction of beta-amyloid (Aβ) plaques with brain vessels, we crossbred an AD mouse model (overexpressing amyloid precursor protein with the Swedish-Dutch-Iowa mutations, APP_SweDI) with mice expressing green fluorescent protein (GFP) under the flt-1/VEGFR1 promoter in vessels (GFP_FLT1). Our data show, that only very few Aβ plaques were seen in 4-months old mice, focused in the mammillary body and in the lateral septal nucleus. The number of plaques markedly increased with age being most prominent in 12-months old mice. Thiazine Red was used to verify the plaques. Several Thiazine Red(+) inclusions were found in GFP(+) vessels, but only in non-perfused 4-months old mice. These inclusions were verified by Resorufin stainings possibly representing cerebral amyloid angiopathy. The inclusions were also seen in non-crossbred APP_SweDI but not in wildtype and GFP_FLT1 mice. In order to characterize these inclusions Flow Cytometry (FACS) analysis demonstrated that platelets were specifically stained by Thiazine Red(+), more pronounced when aggregated. In conclusion, our data show that Thiazine Red(+) inclusions representing aggregated platelets are a first pathological sign in AD before plaque development and may become important therapeutic targets in early AD. PMID:27345467

  11. Tumor Blood Vessel Dynamics

    Science.gov (United States)

    Munn, Lance

    2009-11-01

    ``Normalization'' of tumor blood vessels has shown promise to improve the efficacy of chemotherapeutics. In theory, anti-angiogenic drugs targeting endothelial VEGF signaling can improve vessel network structure and function, enhancing the transport of subsequent cytotoxic drugs to cancer cells. In practice, the effects are unpredictable, with varying levels of success. The predominant effects of anti-VEGF therapies are decreased vessel leakiness (hydraulic conductivity), decreased vessel diameters and pruning of the immature vessel network. It is thought that each of these can influence perfusion of the vessel network, inducing flow in regions that were previously sluggish or stagnant. Unfortunately, when anti-VEGF therapies affect vessel structure and function, the changes are dynamic and overlapping in time, and it has been difficult to identify a consistent and predictable normalization ``window'' during which perfusion and subsequent drug delivery is optimal. This is largely due to the non-linearity in the system, and the inability to distinguish the effects of decreased vessel leakiness from those due to network structural changes in clinical trials or animal studies. We have developed a mathematical model to calculate blood flow in complex tumor networks imaged by two-photon microscopy. The model incorporates the necessary and sufficient components for addressing the problem of normalization of tumor vasculature: i) lattice-Boltzmann calculations of the full flow field within the vasculature and within the tissue, ii) diffusion and convection of soluble species such as oxygen or drugs within vessels and the tissue domain, iii) distinct and spatially-resolved vessel hydraulic conductivities and permeabilities for each species, iv) erythrocyte particles advecting in the flow and delivering oxygen with real oxygen release kinetics, v) shear stress-mediated vascular remodeling. This model, guided by multi-parameter intravital imaging of tumor vessel structure

  12. MR vascular fingerprinting: A new approach to compute cerebral blood volume, mean vessel radius, and oxygenation maps in the human brain.

    Science.gov (United States)

    Christen, T; Pannetier, N A; Ni, W W; Qiu, D; Moseley, M E; Schuff, N; Zaharchuk, G

    2014-04-01

    In the present study, we describe a fingerprinting approach to analyze the time evolution of the MR signal and retrieve quantitative information about the microvascular network. We used a Gradient Echo Sampling of the Free Induction Decay and Spin Echo (GESFIDE) sequence and defined a fingerprint as the ratio of signals acquired pre- and post-injection of an iron-based contrast agent. We then simulated the same experiment with an advanced numerical tool that takes a virtual voxel containing blood vessels as input, then computes microscopic magnetic fields and water diffusion effects, and eventually derives the expected MR signal evolution. The parameter inputs of the simulations (cerebral blood volume [CBV], mean vessel radius [R], and blood oxygen saturation [SO2]) were varied to obtain a dictionary of all possible signal evolutions. The best fit between the observed fingerprint and the dictionary was then determined by using least square minimization. This approach was evaluated in 5 normal subjects and the results were compared to those obtained by using more conventional MR methods, steady-state contrast imaging for CBV and R and a global measure of oxygenation obtained from the superior sagittal sinus for SO2. The fingerprinting method enabled the creation of high-resolution parametric maps of the microvascular network showing expected contrast and fine details. Numerical values in gray matter (CBV=3.1±0.7%, R=12.6±2.4μm, SO2=59.5±4.7%) are consistent with literature reports and correlated with conventional MR approaches. SO2 values in white matter (53.0±4.0%) were slightly lower than expected. Numerous improvements can easily be made and the method should be useful to study brain pathologies. PMID:24321559

  13. Relaxation oscillation model of hemodynamic parameters in the cerebral vessels

    Science.gov (United States)

    Cherevko, A. A.; Mikhaylova, A. V.; Chupakhin, A. P.; Ufimtseva, I. V.; Krivoshapkin, A. L.; Orlov, K. Yu

    2016-06-01

    Simulation of a blood flow under normality as well as under pathology is extremely complex problem of great current interest both from the point of view of fundamental hydrodynamics, and for medical applications. This paper proposes a model of Van der Pol - Duffing nonlinear oscillator equation describing relaxation oscillations of a blood flow in the cerebral vessels. The model is based on the patient-specific clinical experimental data flow obtained during the neurosurgical operations in Meshalkin Novosibirsk Research Institute of Circulation Pathology. The stability of the model is demonstrated through the variations of initial data and coefficients. It is universal and describes pressure and velocity fluctuations in different cerebral vessels (arteries, veins, sinuses), as well as in a laboratory model of carotid bifurcation. Derived equation describes the rheology of the ”blood stream - elastic vessel wall gelatinous brain environment” composite system and represents the state equation of this complex environment.

  14. Middle cerebral artery blood velocity during rowing

    DEFF Research Database (Denmark)

    Secher, Niels Henry; Pott, F; Knudsen, L.;

    1997-01-01

    original,arterial blood pressure,central venous pressure,cerebral blood flow, exercise, transcranial Doppler......original,arterial blood pressure,central venous pressure,cerebral blood flow, exercise, transcranial Doppler...

  15. Blood vessel rupture by cavitation

    OpenAIRE

    Chen, Hong; Brayman, Andrew A.; Bailey, Michael R.; Matula, Thomas J.

    2010-01-01

    Cavitation is thought to be one mechanism for vessel rupture during shock wave lithotripsy treatment. However, just how cavitation induces vessel rupture remains unknown. In this work, a high-speed photomicrography system was set up to directly observe the dynamics of bubbles inside blood vessels in ex vivo rat mesenteries. Vascular rupture correlating to observed bubble dynamics were examined by imaging bubble extravasation and dye leakage. The high-speed images show that bubble expansion ca...

  16. Mechanism and treatment principle for cerebral vessel spasm caused by concussion

    Institute of Scientific and Technical Information of China (English)

    肖兴义; 郭新红; 王德文; 薛关生

    2002-01-01

    Objective: To discuss the mechanism of cerebral vessel spasm caused by concussion and the effect of Nimodipine on concussion. Methods: A total of 224 patients who were treated from March 1995 to October 1999 were divided into two groups randomly, ie, Nimodipine group (113 cases) and control group (111 cases). Middle cerebral artery (MCA), basilar artery (BA) and the average peak forward velocity of cerebral blood flow were observed by color three-dimensional transcranial Doppler (3D-TCD) within 24 hours after admission and at the end of 3-6 days of treatment. Cerebral blood flow changes, characteristics and treatment effect were analyzed and determined by clinical main symptom disappearance rate. Results: In concussion, cerebral blood flow was divided into 3 phases: cerebral blood flow low infusion dilation phase, cerebral blood vessel spasm phase and cerebral blood flow recovery phase. In the Nimodipine group, clinical main symptom disappearance rate was higher than that in the control group in the cerebral spasm and recovery phases with a significant difference (P<0.01).  Conclusions: Cerebral vessel spasm, hypoxia and ischemia lesion are the main pathological changes. Whether cerebral dysfunction is reversible or not is mainly determined by spasm time of cerebral blood vessel. Nimodipine has a good effect on releasing spasm and diminishing the cerebral blood flow velocity. It not only improves curative effect on concussion, but also reduces and prevents concussion sequelae. Hence, concussion patients who have cerebral spasm confirmed by 3D-TCD should be given Nimodipine routinely and early.

  17. [Pulmonary blood vessels in goats].

    Science.gov (United States)

    Roos, H; Hegner, K; Vollmerhaus, B

    1999-05-01

    The blood vessels in the lung of the goat, which until now have received little attention, are described in detail for the first time. With regard to the segments of the lung, blood vessels are bronchovascular units in the lobi craniales, lobus medius and lobus accessorius, but bronchoartery units in the lobi caudales. We investigated the types of branches of the Aa. pulmonales dextra et sinistra, the inter- and intraspecific principles of the outlet of the pulmonary veins and the importance of bronchopulmonary segmentation of the lungs. PMID:10386009

  18. Brain blood vessel segmentation using line-shaped profiles

    International Nuclear Information System (INIS)

    Segmentation of cerebral blood vessels is of great importance in diagnostic and clinical applications, especially for embolization of cerebral aneurysms and arteriovenous malformations (AVMs). In order to perform embolization of the AVM, the structural and geometric information of blood vessels from 3D images is of utmost importance. For this reason, the in-depth segmentation of cerebral blood vessels is usually done as a fusion of different segmentation techniques, often requiring extensive user interaction. In this paper we introduce the idea of line-shaped profiling with an application to brain blood vessel and AVM segmentation, efficient both in terms of resolving details and in terms of computation time. Our method takes into account both local proximate and wider neighbourhood of the processed pixel, which makes it efficient for segmenting large blood vessel tree structures, as well as fine structures of the AVMs. Another advantage of our method is that it requires selection of only one parameter to perform segmentation, yielding very little user interaction. (paper)

  19. Cerebral blood-flow tomography

    DEFF Research Database (Denmark)

    Lassen, N A; Henriksen, L; Holm, S;

    1983-01-01

    Tomographic maps of local cerebral blood flow (CBF) were obtained with xenon-133 and with isopropyl-amphetamine-iodine-123 (IMP) in 11 subjects: one normal, two tumor cases, and eight cerebrovascular cases. A highly sensitive four-face, rapidly rotating, single-photon emission tomograph was used...... sampling, and with low radiation exposure to patient and personnel. On the other hand, IMP gives an image of slightly higher resolution. It also introduces a new class of iodinated brain-seeking compounds allowing, perhaps, imaging of other functions more important than mere blood flow....

  20. Tea May Benefit Blood Vessels

    Institute of Scientific and Technical Information of China (English)

    华剑铭

    2000-01-01

    读到有关饮茶有益健康的消息,我总是充满了自豪感:茶的故乡毕竟在中国。饮茶对人的心脏有益,这已经不是新闻,但是到底如何起到此类保健作用,多年来一直是一个谜。本文揭开了此谜底: Drinking a cup of tea makes blood vessels work better within 2 hours, dilating(扩张)the arteries(动脉)and improving blood flow. 文章令我感动之处在于那些科研人员的敬业精神。比如茶中含有caffeine(咖啡因),饮茶对心脏有利,此“利”是否源于caffeine呢?试验人员为了弄清这 一点,便让另一组受试人员服用等量的caffeine,结果证实:Caffeine had no response on the blood vessel function.】

  1. Digital subtraction angiography of the cerebral vessels by intraarterial injection

    International Nuclear Information System (INIS)

    Three hundred and fifty-seven digital subtraction angiography (DSA) were performed in 184 neurosurgical patients by intraarterial injection. Examinations consisted of 192 carotid angiography, 110 vertebral angiography, 23 aortography, 11 spinal angiography and 21 other angiography. In all examinations, visualization of the vessels was excellent and the complications were never experienced. High contrast sensitivity of DSA resulted in better visualization of tumor stains, phlebogram, and arteries in cerebral arteriovenous malformations with large shunt blood flow than conventional angiography. Selective catheterization into each cerebral arteries was not necessarily demanded for good opacification of the vessels because of high sensitivity. High contrast sensitivity also permitted low concentration of contrast material, small dose of contrast material, and slow injection rate. Low concentration of contrast material reduced pain and heat during injection especially in the external carotid and vertebral angiography. Using slow injection, recoiling of catheter into the aorta was reduced, so that injection from the innominate and subclavian arteries for visualization of origin of the cerebral arteries were always successful. Full study of cerebral arteries by Seldinger's method, if necessary, was easily achieved using DSA even in patient with high age or with severe atherosclerosis. Bolus injection of small dose of contrast material as well as serial imaging was helpful in evaluating hemodynamics in the lesion. Real time display of DSA reduced the time required for angiography and was very convenient for artificial embolization. Besides these advantages, DSA became comparable to conventional angiography in spacial resolution by use of intraarterial injection and could be a preoperative genuine examination as well as a screening method. (author)

  2. Photoacoustic determination of blood vessel diameter

    Science.gov (United States)

    Kolkman, Roy G. M.; Klaessens, John H. G. M.; Hondebrink, Erwin; Hopman, Jeroen C. W.; de Mul, Frits F. M.; Steenbergen, Wiendelt; Thijssen, Johan M.; van Leeuwen, Ton G.

    2004-10-01

    A double-ring sensor was applied in photoacoustic tomographic imaging of artificial blood vessels as well as blood vessels in a rabbit ear. The peak-to-peak time (tgrpp) of the laser (1064 nm) induced pressure transient was used to estimate the axial vessel diameter. Comparison with the actual vessel diameter showed that the diameter could be approximated by 2ctgrpp, with c the speed of sound in blood. Using this relation, the lateral diameter could also precisely be determined. In vivo imaging and monitoring of changes in vessel diameters was feasible. Finally, acoustic time traces were recorded while flushing a vessel in the rabbit ear with saline, which proved that the main contribution to the laser-induced pressure transient is caused by blood inside the vessel and that the vessel wall gives only a minor contribution.

  3. Photoacoustic determination of blood vessel diameter

    International Nuclear Information System (INIS)

    A double-ring sensor was applied in photoacoustic tomographic imaging of artificial blood vessels as well as blood vessels in a rabbit ear. The peak-to-peak time (τpp) of the laser (1064 nm) induced pressure transient was used to estimate the axial vessel diameter. Comparison with the actual vessel diameter showed that the diameter could be approximated by 2cτpp, with c the speed of sound in blood. Using this relation, the lateral diameter could also precisely be determined. In vivo imaging and monitoring of changes in vessel diameters was feasible. Finally, acoustic time traces were recorded while flushing a vessel in the rabbit ear with saline, which proved that the main contribution to the laser-induced pressure transient is caused by blood inside the vessel and that the vessel wall gives only a minor contribution

  4. Middle cerebral artery blood velocity during running

    DEFF Research Database (Denmark)

    Lyngeraa, Tobias; Pedersen, Lars Møller; Mantoni, T;

    2013-01-01

    Running induces characteristic fluctuations in blood pressure (BP) of unknown consequence for organ blood flow. We hypothesized that running-induced BP oscillations are transferred to the cerebral vasculature. In 15 healthy volunteers, transcranial Doppler-determined middle cerebral artery (MCA...

  5. MDCTA diagnosis of cerebral vessel disease among patients with arterial hypertension

    International Nuclear Information System (INIS)

    to study changes involving cerebral vessels in patients with hypertension and various levels of total cardiovascular risk. One hundred and thirty-four patients underwent CT-angiography of intracranial vessels. Ninety-eight of them were diagnosed with hypertension. Taking into consideration high blood pressure, presence of risk factors and target organ damage subjects were divided into 4 groups: with low, medium, high and very high total cardiovascular risk. Control group included 36 patients. They were not diagnosed with hypertension at the time of examination. One hundred and five patients were examined using a 4-slice CT scanner (Toshiba Asteion 4, Toshiba Medical System, Japan), and 29 patients were examined using a 128-slice scanner (Siemens Definition AS+, Siemens Healthcare, Germany) with an injection system. We used iodine-containing contrast agents such as iodixanol and iopromide for angiography. Anatomical and topographic changes of cerebral vessels were most frequently found in hypertensive patients with high and very high total cardiovascular risk. Narrowing of vertebral vessels was the most common change (27 patients (27.55%), 21 patients (21.43%) had narrowing of the right artery, and 6 (6.12%) subjects – of the left one). Tortuous course of internal carotid arteries at the neck level was visualized in 11 patients (11.22%). Narrowing of A1 segment of anterior cerebral artery was noted in 9 patients (9.18%), of the right one – in 8 patients (8.16%), of the left one – in 1 patient (1.02%). Aneurysmal dilation of intracranial vessels was visualized in 6 patients (6.12%). Saccular aneurysm of left internal carotid artery was diagnosed in 2 patients (2.04%), one patient (1.02%) had right internal carotid artery aneurysm and one patient (1.02%) had an aneurysm of the basilar artery. the most common changes of cerebral vessels diagnosed in MDCTA among patients with hypertension included various degrees of narrowing of vertebral vessels, anterior

  6. Brief cognitive assessment for patients with cerebral small vessel disease

    OpenAIRE

    O'Sullivan, M.; Morris, R; Markus, H

    2005-01-01

    Background: Cerebral small vessel disease is a common cause of cognitive impairment and vascular dementia. The cognitive deficit differs from that in Alzheimer's disease, with greater executive/attentional dysfunction and relatively intact episodic memory.

  7. Cerebral large vessel vasculitis in systemic lupus erythematosus.

    Science.gov (United States)

    Böckle, B C; Jara, D; Aichhorn, K; Junker, D; Berger, T; Ratzinger, G; Sepp, N T

    2014-11-01

    Neuropsychiatric systemic lupus erythematosus (NPSLE) is defined by involvement of the central nervous system in systemic lupus erythematosus (SLE), with a wide range of both neurological and psychiatric manifestations. Although its aetiopathogenesis is not fully elucidated, NPSLE seems to be a consequence of cerebral vascular pathology including thromboembolism, small-vessel vasculopathy and, in rare cases, true vasculitis. Cerebral vasculitis is rare, and cerebral large-vessel vasculitis in SLE is even more unusual. We report the case of a female patient with the diagnosis of SLE. She presented with stroke-like symptoms, headache and vertigo, and palpable purpura on her legs. Further investigations revealed that she suffered from both vasculitis of the cerebral large vessels and coexisting cutaneous small-vessel vasculitis. PMID:24969082

  8. Complete Blood Count and Retinal Vessel Calibers

    OpenAIRE

    Liew, Gerald; Wang, Jie Jin; Rochtchina, Elena; Wong, Tien Yin; Mitchell, Paul

    2014-01-01

    Objective The influence of hematological indices such as complete blood count on microcirculation is poorly understood. Retinal microvasculature can be directly visualized and vessel calibers are associated with a range of ocular and systemic diseases. We examined the association of complete blood count with retinal vessel calibers. Methods Cross-sectional population-based Blue Mountains Eye Study, n = 3009, aged 49+ years. Complete blood count was measured from fasting blood samples taken at...

  9. Amylin: Localization, Effects on Cerebral Arteries and on Local Cerebral Blood Flow in the Cat

    Directory of Open Access Journals (Sweden)

    Lars Edvinsson

    2001-01-01

    Full Text Available Amylin and adrenomedullin are two peptides structurally related to calcitonin gene-related peptide (CGRP. We studied the occurrence of amylin in trigeminal ganglia and cerebral blood vessels of the cat with immunocytochemistry and evaluated the role of amylin and adrenomedullin in the cerebral circulation by in vitro and in vivo pharmacology. Immunocytochemistry revealed that numerous nerve cell bodies in the trigeminal ganglion contained CGRP immunoreactivity (-ir; some of these also expressed amylin-ir but none adrenomedullin-ir. There were numerous nerve fibres surrounding cerebral blood vessels that contained CGRP-ir. Occasional fibres contained amylin-ir while we observed no adrenomedullin-ir in the vessel walls. With RT-PCR and Real-Time�PCR we revealed the presence of mRNA for calcitonin receptor-like receptor (CLRL and receptor-activity-modifying proteins (RAMPs in cat cerebral arteries. In vitro studies revealed that amylin, adrenomedullin, and CGRP relaxed ring segments of the cat middle cerebral artery. CGRP and amylin caused concentration-dependent relaxations at low concentrations of PGF2a-precontracted segment (with or without endothelium whereas only at high concentration did adrenomedullin cause relaxation. CGRP8-37 blocked the CGRP and amylin induced relaxations in a parallel fashion. In vivo studies of amylin, adrenomedullin, and CGRP showed a brisk reproducible increase in local cerebral blood flow as examined using laser Doppler flowmetry applied to the cerebral cortex of the a-chloralose�anesthetized cat. The responses to amylin and CGRP were blocked by CGRP8-37. The studies suggest that there is a functional sub-set of amylin-containing trigeminal neurons which probably act via CGRP receptors.

  10. 3D-Gd-DTPA MR angiography of cerebral blood vessels: A comparison with conventional 3D-MR subtraction angiography

    International Nuclear Information System (INIS)

    Subtraction angiography based on 3D fast imaging techniques using rephasing and dephasing gradient pulses is widely used, resulting in angiograms which closely correlate with DSA. Similar angiograms can be obtained with 3D-gradient echo techniques before and after the administration of Gadolinium (Gd)-DTPA (0.1-0.2 mmol/kg) followed by image subtraction. As Gd-DTPA does not penetrate the blood-brain barrier, brain imaging is not altering by the contrast agent. Both techniques were compared in patients wihout vascular disease, venous sinus thrombosis, AV malformation and aneurysm. With both techniques the cerebro-vascular system was imaged favoring the venous system because of the more constant flow velocity and the lack of ECG synchronization. Gd-DTPA offers the advantage of the higher signal-to-noise ratio and is hampered by background superposition due to Gd-DTPA enhancement in non brain tissue. With both techniques vessels down to 1 mm can be imaged. (orig.)

  11. Morphometric evaluation of endometrial blood vessels

    Directory of Open Access Journals (Sweden)

    Makhija Divya

    2008-07-01

    Full Text Available Five hundred endometrial specimens were studied to document the changes in blood vessels in various phases of menstrual cycle, menstrual disturbances and in unexplained infertility. Sixty-three cases were taken as control and 437 cases as study group which included cases of dysfunctional uterine bleeding (DUB, endometrial polyps, fibroids, adenomyosis, infertility and atrophic endometrium. Using light microscopy, the vascular morphology was studied. The blood vessels were concentrated more in basal layer in the proliferative phase and in functional layer in the secretory phase. Cases of complex hyperplasia and pill endometrium had significantly higher vessel concentration. Congestion and dilatation of blood vessels were significantly higher in cases of DUB. The present study showed a positive correlation between endometrial angiogenesis and menstrual disorders. The alteration in blood vessel morphology has significant role in prognosis and in various anti-angiogenic therapies.

  12. A CASE OF POLYCYTHEMIA SHOWING HYPERDENSE CEREBRAL VESSELS ON NON-CONTRAST COMPUTED TOMOGRAPHY SCAN

    Directory of Open Access Journals (Sweden)

    Bijit Kr

    2015-12-01

    Full Text Available Polycythemia is a disease state in which the proportion of blood volume that is occupied by red blood cells increases. It can result in increased density of intracranial blood vessels on non-contrast computed tomography scan. This imaging findings can closely mimic appearance of a contrast enhanced CT scan and those of cerebral venous thrombosis. We are presenting a case of 11-year-old child with Fallot’s tetralogy who showed abnormally hyperdense intracranial vessels on NCCT of brain.

  13. Classification & Structure of Blood Vessels

    Science.gov (United States)

    ... Thyroid & Parathyroid Glands Adrenal Gland Pancreas Gonads Other Endocrine Glands Review Quiz Cardiovascular System Heart Structure of the Heart Physiology of the Heart Blood Classification & Structure of Blood ...

  14. Simultaneous imaging of intrinsic optical signals and cerebral vessel responses during cortical spreading depression in rats

    Science.gov (United States)

    Li, Pengcheng; Chen, Shangbin; Luo, Weihua; Luo, Qingming

    2003-12-01

    Cortical spreading depression (CSD) is an important disease model for migraine and cerebral ischemia. We investigated the spatio-temporal characteristics of the intrinsic optical signals (IOS) at 570 nm and the cerebral blood vessel responses during CSD simultaneously by optical reflectance imaging in vivo. The CSD were induced by pinprick in 10 α-chloralose/urethane anesthetized Sprague-Dawley rats. A four-phasic IOS response was observed at pial arteries and parenchymal sites in all experimental animals and an initial slight pial arteries dilation (21.5%+/-13.6%) and constriction (-4.2%+/-3.5%) precedes the dramatic dilation (69.2%+/-26.1%) of pial arterioles was recorded. Our experimental results show a high correlation (r = 0.89+/-0.025) between the IOS response and the diameter changes of the cerebral blood vessels during CSD in rats.

  15. Cerebral angiography, blood flow and vascular reactivity in progressive hypertension

    Science.gov (United States)

    Li, Yunxia; Shen, Qiang; Huang, Shiliang; Li, Wei; Muir, Eric R.; Long, Justin; Duong, Timothy Q.

    2015-01-01

    Chronic hypertension alters cerebral vascular morphology, cerebral blood flow (CBF), cerebrovascular reactivity, increasing susceptibility to neurological disorders. This study evaluated: i) the lumen diameters of major cerebral and downstream arteries using magnetic resonance angiography, and ii) basal CBF, and iii) cerebrovascular reactivity to hypercapnia of multiple brain regions using arterial-spin-labeling technique in spontaneously hypertensive rats (SHR) at different stages. Comparisons were made with age-matched normotensive Wistar Kyoto (WKY) rats. In 10-week SHR, lumen diameter started to reduce, basal CBF, and hypercapnic CBF response were higher from elevated arterial blood pressure, but there was no evidence of stenosis, compared to age-matched WKY. In 20-week SHR, lumen diameter remained reduced, CBF returned toward normal from vasoconstriction, hypercapnic CBF response reversed and became smaller, but without apparent stenosis. In 40-week SHR, lumen diameter remained reduced and basal CBF further decreased, resulting in larger differences compared to WKY. There was significant stenosis in main supplying cerebral vessels. Hypercapnic CBF response further decreased, with some animals showing negative hypercapnic CBF responses in some brain regions, indicative of compromised cerebrovascular reserve. The territory with negative hypercapnia CBF responses corresponded with the severity of stenosis in arteries that supplied those territories. We also found enlargement of downstream vessels and formation of collateral vessels as compensatory responses to vasoconstriction upstream vessels. The middle cerebral and azygos arteries were amongst the most susceptible to hypertension-induced changes. Multimodal MRI provides clinically relevant data that might be useful to characterize disease pathogenesis, stage disease progression, and monitor treatment effects in hypertension. PMID:25731987

  16. The development of cerebral amyloid angiopathy in cerebral vessels. A review with illustrations based upon own investigated post mortem cases.

    Science.gov (United States)

    Mendel, T A; Wierzba-Bobrowicz, T; Lewandowska, E; Stępień, T; Szpak, G M

    2013-12-01

    The process of β-amyloid accumulation in cerebral vessels is presented. Cerebral amyloid angiopathy (CAA) was confirmed during an autopsy. It was diagnosed according to the Boston criteria. Cerebral amyloid angiopathy can involve all kinds of cerebral vessels (cortical and leptomeningeal arterioles, capillaries and veins). The development of CAA is a progressive process. β-amyloid appears first in the tunica media, surrounding smooth muscle cells, and in the adventitia. β-amyloid is progressively accumulated, causing a gradual loss of smooth muscle cells in the vessel wall and finally replacing them. Then, the detachment and delamination of the outer part of the tunica media results in the "double barrel" appearance, fibrinoid necrosis, and microaneurysm formation. Microbleeding with perivascular deposition of erythrocytes and blood breakdown products can also occur. β-amyloid can also be deposited in the surrounding of the affected vessels of the brain parenchyma, known as "dysphoric CAA". Ultrastructurally, when deposits of amyloid fibers were localized in or outside the arteriolar wall, the degenerating vascular smooth muscle cells were observed. In the Institute of Psychiatry and Neurology the study was carried out in a group of 48 patients who died due to intracerebral hemorrhage caused by sporadic CAA. PMID:24375040

  17. BLOOD VESSELS EXTRACTION USING MATHEMATICAL MORPHOLOGY

    Directory of Open Access Journals (Sweden)

    Nidhal Khdhair El Abbadi

    2013-01-01

    Full Text Available The retinal vasculature is composed of the arteries and veins with their tributaries which are visible within the retinal image. The segmentation and measurement of the retinal vasculature is of primary interest in the diagnosis and treatment of a number of systemic and ophthalmologic conditions. The accurate segmentation of the retinal blood vessels is often an essential prerequisite step in the identification of retinal anatomy and pathology. In this study, we present an automated approach for blood vessels extraction using mathematical morphology. Two main steps are involved: enhancement operation is applied to the original retinal image in order to remove the noise and increase contrast of retinal blood vessels and morphology operations are employed to extract retinal blood vessels. This operation of segmentation is applied to binary image of top-hat transformation. The result was compared with other algorithms and give better results.

  18. 血糖水平对急性脑血管病患者神经功能恢复的影响%The influence of blood sugar level on the recovery of patients' nerve function of acute cerebral vessel disease

    Institute of Scientific and Technical Information of China (English)

    郝淑梅; 石寄平; 谢艳萍

    2001-01-01

    @@ Background:Diabetes mellitus is one of risk factors leading to acute cerebral vessel disease(ACVD),and people have paid more attention to the fact that increase of blood sugar level after ACVD can aggravate nerve system impairment. Objective:To study the influence of blood sugar level increase on the recovery of nerve function of ACVD. Design:To make retrospective analysis on the relationship between prognosis and ACVD blood sugar level increase,the 157 patients lived in our hospital between March 1995 and March 2001.

  19. Assessment of maternal cerebral blood flow in patients with preeclampsia

    Directory of Open Access Journals (Sweden)

    Mandić Vesna

    2005-01-01

    patients with signs of threatened eclampsia, suggesting that blood vessels changes are most prominent in severe preeclampsia. Cerebral blood flow measurements can be used as a clinical test for the prediction of eclampsia. Magnesium-sulfate (MgSO4 has a significant role in prophylaxis and treatment of eclampsia, and, therefore, positive influence on reduction of cerebral ishemic lesions can be expected. Conclusion We can conclude that changes of the cerebral blood flow can be evaluated by evaluating blood flow velocities in the medial cerebral artery. Velocities tend to increase in severe preeclampsia, especially with signs of threatening eclampsia, and decrease after treatment with magnesium sulfate. Serial measurements of blood flow in medial cerebral artery in patients with severe preeclampsia may be used in prediction of eclampsia and in evaluation of magnesium sulfate therapy effects.

  20. Regional cerebral blood flow in schizophrenia

    International Nuclear Information System (INIS)

    Regional cerebral blood flow (rCBF) was measured via xenon133 inhalation technique in 23 patients with schizophrenia and 18 age- and sex-matched controls. The mean blood flow to both hemispheres was found to be lower for the patients. The patients and their controls did not differ on interhemispheric differences in blood flow. There were no differences in rCBF between medicated and unmedicated, subchronic and chronic, and paranoid and nonparanoid patients. Hallucinations were associated with reduced blood flow to several postcentral regions

  1. Videodensitometry for measuring blood vessel diameter

    International Nuclear Information System (INIS)

    A method employing a special computer for determining the internal diameters of blood vessels from photofluorographic image is described; in vitro and in vivo experiments are performed with the system. The amount of contrast medium injected is restricted to 4x3 ml, and it is possible to determine the diameter (in the range from 2 to 16 mm) at any place where blood vessels can be catheterized. In the in vivo experiments the maximum systematic error is +-5 per cent in the 7 to 8 mm range. (Auth.)

  2. Videodensitometry for measuring blood vessel diameter.

    Science.gov (United States)

    Hoornstra, K; Hanselman, J M; Holland, W P; De Wey Peters, G W; Zwamborn, A W

    1980-01-01

    A method employing a special computer for determining the internal diameters of blood vessels from photofluorographic image is described; in vitro and in vivo experiments are performed with the system. The amount of contrast medium injected is restricted to 4 times 3 ml, and it is possible to determine the diameter (in the range from 2 to 16 mm) at any place where blood vessels can be catheterized. In the in vivo experiments the maximum systematic error is +/-5 percent in the 7 to 8 mm range. PMID:7424549

  3. Regional cerebral blood flow in aphasia

    DEFF Research Database (Denmark)

    Soh, K; Larsen, B; Skinhøj, E;

    1978-01-01

    Regional cerebral blood flow (rCBF) was studied in 13 aphasic patients with left hemisphere lesions, using the intracarotid xenon 133 injection method and a 254-detector gamma camera system. The rCBF was measured during rest and during various function tests, including a simple speech test. In...

  4. Cerebral blood flow in acute mountain sickness

    DEFF Research Database (Denmark)

    Jensen, J B; Wright, Anne; Lassen, N A;

    1990-01-01

    Changes in cerebral blood flow (CBF) were measured using the radioactive xenon technique and were related to the development of acute mountain sickness (AMS). In 12 subjects, ascending from 150 to 3,475 m, CBF was 24% increased at 24 h [45.1 to 55.9 initial slope index (ISI) units] and 4% increased...

  5. Complete blood count and retinal vessel calibers.

    Directory of Open Access Journals (Sweden)

    Gerald Liew

    Full Text Available OBJECTIVE: The influence of hematological indices such as complete blood count on microcirculation is poorly understood. Retinal microvasculature can be directly visualized and vessel calibers are associated with a range of ocular and systemic diseases. We examined the association of complete blood count with retinal vessel calibers. METHODS: Cross-sectional population-based Blue Mountains Eye Study, n = 3009, aged 49+ years. Complete blood count was measured from fasting blood samples taken at baseline examination, 1992-4. Retinal arteriolar and venular calibers were measured from digitized retinal photographs using a validated semi-automated computer program. RESULTS: All analyses adjusted for age, sex, systolic blood pressure, diabetes, smoking and fellow vessel caliber. Higher hematocrit, white cell count and platelet count were associated with narrower arteriolar caliber (p = 0.02, 0.03 and 0.001 respectively, while higher hemoglobin, hematocrit, red cell count, white cell count and platelet count were associated with wider venular caliber (p<0.0001 for all. Each quintile increase in hematocrit, white cell count and platelet count was associated with approximately 0.5 µm narrower arteriolar caliber; whereas each quintile increase in all of the complete blood count components was associated with approximately 1-2 µm wider venular caliber. CONCLUSIONS: These associations show that elevated levels of hematological indices can have adverse effects on the microcirculation.

  6. Cerebral blood flow in humans following resuscitation from cardiac arrest

    International Nuclear Information System (INIS)

    Cerebral blood flow was measured by xenon-133 washout in 13 patients 6-46 hours after being resuscitated from cardiac arrest. Patients regaining consciousness had relatively normal cerebral blood flow before regaining consciousness, but all patients who died without regaining consciousness had increased cerebral blood flow that appeared within 24 hours after resuscitation (except in one patient in whom the first measurement was delayed until 28 hours after resuscitation, by which time cerebral blood flow was increased). The cause of the delayed-onset increase in cerebral blood flow is not known, but the increase may have adverse effects on brain function and may indicate the onset of irreversible brain damage

  7. Automated measurement of retinal blood vessel tortuosity

    Science.gov (United States)

    Joshi, Vinayak; Reinhardt, Joseph M.; Abramoff, Michael D.

    2010-03-01

    Abnormalities in the vascular pattern of the retina are associated with retinal diseases and are also risk factors for systemic diseases, especially cardiovascular diseases. The three-dimensional retinal vascular pattern is mostly formed congenitally, but is then modified over life, in response to aging, vessel wall dystrophies and long term changes in blood flow and pressure. A characteristic of the vascular pattern that is appreciated by clinicians is vascular tortuosity, i.e. how curved or kinked a blood vessel, either vein or artery, appears along its course. We developed a new quantitative metric for vascular tortuosity, based on the vessel's angle of curvature, length of the curved vessel over its chord length (arc to chord ratio), number of curvature sign changes, and combined these into a unidimensional metric, Tortuosity Index (TI). In comparison to other published methods this method can estimate appropriate TI for vessels with constant curvature sign and vessels with equal arc to chord ratios, as well. We applied this method to a dataset of 15 digital fundus images of 8 patients with Facioscapulohumeral muscular dystrophy (FSHD), and to the other publically available dataset of 60 fundus images of normal cases and patients with hypertensive retinopathy, of which the arterial and venous tortuosities have also been graded by masked experts (ophthalmologists). The method produced exactly the same rank-ordered list of vessel tortuosity (TI) values as obtained by averaging the tortuosity grading given by 3 ophthalmologists for FSHD dataset and a list of TI values with high ranking correlation with the ophthalmologist's grading for the other dataset. Our results show that TI has potential to detect and evaluate abnormal retinal vascular structure in early diagnosis and prognosis of retinopathies.

  8. Zinc oxide nanoflowers make new blood vessels

    Science.gov (United States)

    Barui, Ayan Kumar; Veeriah, Vimal; Mukherjee, Sudip; Manna, Joydeb; Patel, Ajay Kumar; Patra, Sujata; Pal, Krishnendu; Murali, Shruthi; Rana, Rohit K.; Chatterjee, Suvro; Patra, Chitta Ranjan

    2012-11-01

    It is well established that angiogenesis is the process of formation of new capillaries from pre-existing blood vessels. It is a complex process, involving both pro- and anti-angiogenic factors, and plays a significant role in physiological and pathophysiological processes such as embryonic development, atherosclerosis, post-ischemic vascularization of the myocardium, tumor growth and metastasis, rheumatoid arthritis etc. This is the first report of zinc oxide (ZnO) nanoflowers that show significant pro-angiogenic properties (formation of new capillaries from pre-existing blood vessels), observed by in vitro and in vivo angiogenesis assays. The egg yolk angiogenesis assay using ZnO nanoflowers indicates the presence of matured blood vessels formation. Additionally, it helps to promote endothelial cell (EA.hy926 cells) migration in wound healing assays. Formation of reactive oxygen species (ROS), especially hydrogen peroxide (H2O2)--a redox signaling molecule, might be the plausible mechanism for nanoflower-based angiogenesis. Angiogenesis by nanoflowers may provide the basis for the future development of new alternative therapeutic treatment strategies for cardiovascular and ischemic diseases, where angiogenesis plays a significant role.It is well established that angiogenesis is the process of formation of new capillaries from pre-existing blood vessels. It is a complex process, involving both pro- and anti-angiogenic factors, and plays a significant role in physiological and pathophysiological processes such as embryonic development, atherosclerosis, post-ischemic vascularization of the myocardium, tumor growth and metastasis, rheumatoid arthritis etc. This is the first report of zinc oxide (ZnO) nanoflowers that show significant pro-angiogenic properties (formation of new capillaries from pre-existing blood vessels), observed by in vitro and in vivo angiogenesis assays. The egg yolk angiogenesis assay using ZnO nanoflowers indicates the presence of matured blood

  9. Cerebral blood flow tomography with xenon-133

    DEFF Research Database (Denmark)

    Lassen, N A

    1985-01-01

    Cerebral blood flow (CBF) can be measured tomographically by inhalation of Xenon-133. The calculation is based on taking a sequence of tomograms during the wash-in and wash-out phase of the tracer. Due to the dynamic nature of the process, a highly sensitive and fast moving single photon emission...... other tracers for CBF tomography using SPECT is summarized with emphasis on the 99mTc chelates that freely pass the intact blood-brain barrier. The highly sensitive brain-dedicated SPECT systems described are a prerequisite for achieving high resolution tomograms with such tracers....

  10. New possibilities for quantitative measurements of regional cerebral blood flow with gold-195m

    International Nuclear Information System (INIS)

    A previously reported theory for quantitative cerebral blood flow measurement for nondiffusible radiotracers has been applied to patients after stroke and to volunteers undergoing a mental stimulation exercise. The energy spectrum of gold-195m shows two strong photon peaks, one at an energy level of 68 keV and a second at an energy-level of 262 keV. The low energy peak is suitable for perfusion studies in lateral views of the hemispheres; no look-through effect is seen. The high energy level is good for studies in posterior-anterior positions. Parametric images for quantitative regional cerebral blood flow can be generated. The area of occluded vessels in the case of stroke can be detected. Quantitative activation patterns of cerebral blood flow during mental stimulation can be generated. The results prove that, not only with freely diffusible indicators like xenon but also with nondiffusible indicators, it is possible to measure quantitatively cerebral blood flow patterns

  11. Endothelium-dependent relaxation of blood vessels

    International Nuclear Information System (INIS)

    Dilation of blood vessels in response to a large number of agents has been shown to be dependent on an intact vascular endothelium. The present studies examine some aspects of endothelium-dependent vasodilation in blood vessels of the rabbit and rat. Using the rabbit ear artery and the subtype-selective muscarinic antagonist pirenzepine, muscarinic receptors of the endothelium and smooth muscle cells were shown to be of the low affinity M2 subtype. Inhibition of [3H](-)quinuclidinyl benzilate was used to determine affinity for the smooth muscle receptors while antagonism of methacholine induced vasodilation yielded the endothelial cell receptor affinity. The effect of increasing age (1-27 months) on endothelium-dependent relaxation was studied in aortic rings, perfused tail artery and perfused mesenteric bed of the Fisher 344 rat. The influence of endothelium on contractile responses was examined using the perfused caudal artery

  12. Trigeminal origin or B-preprotachykinin products in feline pial blood vessels

    International Nuclear Information System (INIS)

    A specific and sensitive radioimmunoassay measured the presence of immunoreactive neurokinin A within feline and human pial arteries. Immunoreactivity exhibited a retention time identical to that of synthetic peptide when acid extracts from feline and human blood vessels were subjected to reverse-phase high-performance liquid chromatography. As shown previously for substance P, levels of immunoreactive neurokinin A decreased significantly in the vessels from the ipsilateral rostral circle of Willis l9-24 days following unilateral trigeminal ganglionectomy. Hence, trigeminal projections to cerebral blood vessels contain both products of B-preprotachykinin mRNA. (author)

  13. Regional cerebral blood flow in schizophrenic patients

    International Nuclear Information System (INIS)

    Seventy-six schizophrenic patients were examined by a Xe-133 inhalation method to determine regional cerebral blood flow. A decreased blood flow was observed in the frontal lobe, especially in the right inferior part. In a study on the relationship between disease subtypes and regional cerebral blood flow, negative symptoms were found more predominantly associated with dissolution type than delusion type. In the group of dissolution type, a decreased blood flow was observed in both the right inferior frontal lobe and the right upper hemisphere, in comparison to the group of delution type. Patients presenting with auditory hallucination had a significantly higher incidence of both negative and positive symptoms, as compared with those not presenting with it. In such patients, a significantly decreased blood flow was also seen in the left upper frontal lobe and the bilateral parietal lobe. Xe-133 inhalation method should assist in evaluating brain function in schizophrenic patients, thus leading to the likelihood of developing a new treatment modality. (N.K.)

  14. Noninvasive blood pressure measurement in large vessels

    International Nuclear Information System (INIS)

    Pulse pressure in the aorta was evaluated by the measurement of pulse wave velocity (PWV) and blood flow velocity (BFV). PWV reflects the elasticity of the vessel and was determined by a time-of-flight method. BFV was measured by analyzing the change of magnetization decay due to flow in multiecho experiments. If one neglects pulse wave reflections at vascular branch points and flow resistance due to blood viscosity, pulse pressure is proportional to PWV and BFV. Noninvasive MR imaging measurements were obtained in 12 patients, all of whom underwent correlative arterial catheterization. Values varied between 35 and 100 mm Hg. The results demonstrated a high correlation between the two methods

  15. Water hammer experiment in artificial blood vessel

    Czech Academy of Sciences Publication Activity Database

    Hromádka, D.; Horný, L.; Žitný, R.; Chlup, Hynek

    Liberec : Technical University of Liberec, 2010 - (Čapek, L.), s. 127-132 ISBN 978-80-7372-648-5. [Human Biomechanics 2010. Sychrov (CZ), 04.10.2010-06.10.2010] R&D Projects: GA ČR(CZ) GA106/08/0557 Institutional research plan: CEZ:AV0Z20760514 Keywords : water hammer * artificial blood vessel * reinforced latex tube Subject RIV: JJ - Other Materials

  16. Designer blood vessels and therapeutic revascularization

    OpenAIRE

    Berglund, Joseph D; Galis, Zorina S.

    2003-01-01

    Inadequate vascular perfusion leads to fatal heart attacks, chronic ulcers, and other serious clinical conditions. The body's capacity to restore vascular perfusion through angiogenesis and arteriogenesis is often impaired by pre-existing disease, and availability of native replacements for nonfunctional arteries is limited in many patients. Thus, recreating blood vessels of various calibres through novel engineering technologies has emerged as a radical option among therapeutic strategies fo...

  17. Early exercise improves cerebral blood flow through increased angiogenesis in experimental stroke rat model

    OpenAIRE

    Zhang, Pengyue; Yu, Huixian; Zhou, Naiyun; Jie ZHANG; Wu, Yi; Zhang, Yuling; Bai, Yulong; Jia, Jie; Zhang, Qi; Tian, Shan; Wu, Junfa; Hu, Yongshan

    2013-01-01

    Background Early exercise after stroke promoted angiogenesis and increased microvessles density. However, whether these newly formatted vessels indeed give rise to functional vascular and improve the cerebral blood flow (CBF) in impaired brain region is still unclear. The present study aimed to determine the effect of early exercise on angiogenesis and CBF in ischemic region. Methods Adult male Sprague Dawley rats were subjected to 90 min middle cerebral artery occlusion(MCAO)and randomly div...

  18. NADPH Oxidase Activity in Cerebral Arterioles Is a Key Mediator of Cerebral Small Vessel Disease—Implications for Prevention

    Directory of Open Access Journals (Sweden)

    Mark F. McCarty

    2015-04-01

    Full Text Available Cerebral small vessel disease (SVD, a common feature of brain aging, is characterized by lacunar infarcts, microbleeds, leukoaraiosis, and a leaky blood-brain barrier. Functionally, it is associated with cognitive decline, dementia, depression, gait abnormalities, and increased risk for stroke. Cerebral arterioles in this syndrome tend to hypertrophy and lose their capacity for adaptive vasodilation. Rodent studies strongly suggest that activation of Nox2-dependent NADPH oxidase activity is a crucial driver of these structural and functional derangements of cerebral arterioles, in part owing to impairment of endothelial nitric oxide synthase (eNOS activity. This oxidative stress may also contribute to the breakdown of the blood-brain barrier seen in SVD. Hypertension, aging, metabolic syndrome, smoking, hyperglycemia, and elevated homocysteine may promote activation of NADPH oxidase in cerebral arterioles. Inhibition of NADPH oxidase with phycocyanobilin from spirulina, as well as high-dose statin therapy, may have potential for prevention and control of SVD, and high-potassium diets merit study in this regard. Measures which support effective eNOS activity in other ways—exercise training, supplemental citrulline, certain dietary flavonoids (as in cocoa and green tea, and capsaicin, may also improve the function of cerebral arterioles. Asian epidemiology suggests that increased protein intakes may decrease risk for SVD; conceivably, arginine and/or cysteine—which boosts tissue glutathione synthesis, and can be administered as N-acetylcysteine—mediate this benefit. Ameliorating the risk factors for SVD—including hypertension, metabolic syndrome, hyperglycemia, smoking, and elevated homocysteine—also may help to prevent and control this syndrome, although few clinical trials have addressed this issue to date.

  19. Cerebral blood flow and metabolism during sleep

    DEFF Research Database (Denmark)

    Madsen, Peter Lund; 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...

  20. 脑安胶囊治疗高血压脑血管功能异常临床分析%Clinical analysis of cerebral blood vessel dysfunction in patients with hypertension

    Institute of Scientific and Technical Information of China (English)

    朱红潮

    2015-01-01

    目的:观察脑安胶囊治疗高血压脑血管功能异常临床效果.方法:选择我院于2013年7月至2014年7月期间收治的60例高血压脑血管功能异常患者,随机分成两组,每组各30例,对照组的高血压脑血管功能异常患者给予一般干预方法治疗,观察组的高血压脑血管功能异常患者服用脑安胶囊治疗.结果:观察组高血压脑血管功能异常患者治疗后的脑血管功能评分显著优于对照组(P<0.05).结论:脑安胶囊治疗高血压脑血管功能异常效果明显,值得临床推广.%Objective To observe the clinical effect of the treatment of hypertensive cerebral vascular dysfunction by. Give general intervention treatmentMethods in our hospital from July 2013 to 2014 July admitted during the period of 60 cases of hypertensive cerebral vascular function in patients with abnormal were randomly divided into two groups, 30 cases in each group. The control group of hypertensive cerebral vascular function in patients with abnormal, the observation group of hypertensive cerebral blood tube dysfunction in patients taking Naoan capsule in the treatment of.Results after the observation group of hypertensive cerebrovascular function treatment for patients with abnormal cerebrovascular function score was significantly better than the control group (P< 0.05).Conclusion the therapeutic effect of brain an Capsule on hypertensive cerebral vascular dysfunction is obvious, which is worthy of clinical application.

  1. Surfactant bolus instillation: effects of different doses on blood pressure and cerebral blood flow velocities

    OpenAIRE

    Rey, M.; Segerer, Hugo; Kiessling, C.; Obladen, Michael

    1994-01-01

    Fifteen preterm infants suffering from respiratory distress syndrome were randomly allocated to receive either high-dose (200 mg/kg) or low-dose (100 mg/kg) surfactant treatment. Retreatments were done with the low dose. Blood pressure, blood gases and cerebral blood flow velocities were determined before and after 24 bolus instillations. With the high dose mean blood pressure and mean cerebral blood flow velocity dropped significantly. With the low dose only mean cerebral blood flow velocity...

  2. Regional cerebral blood flow in depression

    International Nuclear Information System (INIS)

    Regional cerebral blood flow (rCBF) was measured in patients with endogenous depression by the single photon emission computed tomography (SPECT) using N-isopropyl-p-[123I] iodoamphetamine (IMP). The subjects were 32 patients with endogenous depression and 20 normal controls. These 32 patients, who were divided into 10 unmedicated group and 22 medicated group, were reexamined when the depressed patients reverted to a euthymic state (remission). The value of rCBF was assessed by the corticocerebellar ratio (CCR), which was expressed as a ratio of activity per pixel in the cerebral regions of interests (ROIs) to the activity per pixel in the cerebellum. The depressive patients showed a decrease in rCBF all over the cerebral regions and, especially, the lower rCBF in the left than in the right hemisphere. These changes turned toward normal in a remitted state following treatments, though there was no significant difference in rCBF between the medicated and unmedicated patients. There was a significantly negative correlation between the severity of depressive symptoms and the mean rCBF in a total of patients with depression. These results suggest that psychiatric symptoms in the depressive patients might be related to the left hemispheric dysfunction. (author)

  3. Regional cerebral blood flow in diabetic patients

    International Nuclear Information System (INIS)

    N-isopropyl-p-123I-iodoamphetamine (IMP) was used to quantify the regional cerebral blood flow (r-CBF) in 11 diabetic patients (average age; 67.9 years) and 12 non-diabetic subjects (average age; 67.4 years), none of whom had (cerebrovascular disease (CVD) on CT studies. A reference sampling method by continuous arterial blood sampling was used to quantify r-CBF. There were no significant differences in physiological or laboratory data between diabetic and non-diabetic groups except for fasting plasma glucose and HbA1c levels. The average of r-CBF in each region of cerebrum and cerebellum was significantly lower in diabetic group than that in the control group (p<0.01). These observations show that r-CBF of diabetic patients is reduced, even in the absence of findings of CVD on a CT study. (author)

  4. Regional cerebral blood flow in diabetic patients

    Energy Technology Data Exchange (ETDEWEB)

    Nagamachi, Shigeki; Ono, Shinnichi; Nishikawa, Takushi (Nichinan Hospital of Miyazaki Prefecture (Japan)) (and others)

    1993-02-01

    N-isopropyl-p-[sup 123]I-iodoamphetamine (IMP) was used to quantify the regional cerebral blood flow (r-CBF) in 11 diabetic patients (average age; 67.9 years) and 12 non-diabetic subjects (average age; 67.4 years), none of whom had (cerebrovascular disease (CVD) on CT studies). A reference sampling method by continuous arterial blood sampling was used to quantify r-CBF. There were no significant differences in physiological or laboratory data between diabetic and non-diabetic groups except for fasting plasma glucose and HbA[sub 1c] levels. The average of r-CBF in each region of cerebrum and cerebellum was significantly lower in diabetic group than that in the control group (p<0.01). These observations show that r-CBF of diabetic patients is reduced, even in the absence of findings of CVD on a CT study. (author).

  5. Application of Computational Physics: Blood Vessel Constrictions and Medical Infuses

    CERN Document Server

    Suprijadi,; Subekti, Petrus; Viridi, Sparisoma

    2013-01-01

    Application of computation in many fields are growing fast in last two decades. Increasing on computation performance helps researchers to understand natural phenomena in many fields of science and technology including in life sciences. Computational fluid dynamic is one of numerical methods which is very popular used to describe those phenomena. In this paper we propose moving particle semi-implicit (MPS) and molecular dynamics (MD) to describe different phenomena in blood vessel. The effect of increasing the blood pressure on vessel wall will be calculate using MD methods, while the two fluid blending dynamics will be discussed using MPS. Result from the first phenomenon shows that around 80% of constriction on blood vessel make blood vessel increase and will start to leak on vessel wall, while from the second phenomenon the result shows the visualization of two fluids mixture (drugs and blood) influenced by ratio of drugs debit to blood debit. Keywords: molecular dynamic, blood vessel, fluid dynamic, movin...

  6. Treatment for cerebral small vessel disease: effect of relaxin on the function and structure of cerebral parenchymal arterioles during hypertension.

    Science.gov (United States)

    Chan, Siu-Lung; Sweet, Julie G; Cipolla, Marilyn J

    2013-10-01

    We investigated the effect of hypertension on the function and structure of cerebral parenchymal arterioles (PAs), a major target of cerebral small vessel disease (SVD), and determined whether relaxin is a treatment for SVD during hypertension. PAs were isolated from 18-wk-old female normotensive Wistar-Kyoto (WKY) rats, spontaneous hypertensive rats (SHRs), and SHRs treated with human relaxin 2 for 14 d (4 μg/h; n=8/group) and studied using a pressurized arteriograph system. Hypertension reduced PA inner diameter (58±3 vs. 49±3 μm at 60 mmHg in WKY rats, Prelaxin (56±4 μm, PRelaxin also increased PA distensibility in SHRs (34±2 vs. 10±2% in SHRs, PRelaxin was detected in cerebrospinal fluid (110±30 pg/ml) after systemic administration, suggesting that it crosses the blood-brain barrier (BBB). Relaxin receptors (RXFP1/2) were not detected in cerebral vasculature, but relaxin increased vascular endothelial growth factor (VEGF) and matrix metalloproteinase 2 (MMP-2) expression in brain cortex. Inhibition of VEGF receptor tyrosine kinase (axitinib, 4 mg/kg/d, 14 d) had no effect on increased distensibility with relaxin, but caused outward hypertrophic remodeling of PAs from SHRs. These results suggest that relaxin crosses the BBB and activates MMP-2 in brain cortex, which may interact with PAs to increase distensibility. VEGF appears to be involved in remodeling of PAs, but not relaxin-induced increased distensibility. PMID:23783073

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

    Science.gov (United States)

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

    2012-02-01

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

  8. 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; Schmidt, J F; Secher, N H; Wildschiødtz, Gordon; Holm, S; Lassen, N A

    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...

  9. Low cerebral blood flow in hypotensive perinatal distress

    International Nuclear Information System (INIS)

    Hypoxic brain injury is the most important neurological problem in the neonatal period and accounts for more neurological deficits in children than any other lesion. The neurological deficits are notably mental retardation, epilepsy and cerebral palsy. The pathogenesis has hitherto been poorly understood. Arterial hypoxia has been taken as the obvious mechanism but this does not fully explain the patho-anatomical findings. In the present investigation we have examined the arterial blood pressure and the cerebral blood flow in eight infants a few hours after birth. The 133Xe clearance technique was used for the cerebral blood flow measurements. The study confirmed that perinatal distress may be associated with low arterial blood pressure, and it was shown that cerebral blood flow is very low, 20 ml/100 g/min or less, in hypotensive perinatal distress. It is concluded that cerebral ischaemia plays a crucial role in the development of perinatal hypoxic brain injury. (author)

  10. Morphogenetic mechanisms of blood vessel fusion in the Zebrafish embryo

    OpenAIRE

    Herwig, Lukas Walter

    2012-01-01

    The formation of a vascular network requires the connection and formation of a lumen between individual endothelial sprouts, a process called vessel fusion or anastomosis. In the vertebrate trunk of the zebrafish (Danio rerio), the intersegmental vessels (ISVs) develop by angiogenesis, i.e. the formation of new vessels by pre-existing vessels, in a conserved metameric manner, which allows the analysis of morphogenetic mechanisms of blood vessel development. From the dorsal aorta (DA) individu...

  11. Blood Vessel Diameter Estimation System Using Active Contours

    OpenAIRE

    Courtney, Jane; Tizon, Ana

    2011-01-01

    The study and analysis of blood vessel geometry has become the basis of medical applications related to early diagnosis and effective monitoring of therapies in vascular diseases. This paper presents a new method to trace the outline of blood vessels from imperfect images and extract useful information about their dimensions in an automated manner. The system consists of a segmentation procedure that uses two Active Contours to detect blood vessel boundaries and a novel approach to measure bl...

  12. Cerebral hemodynamics in aging : the interplay between blood pressure, cerebral perfusion, and dementia

    OpenAIRE

    Claassen, J.A.H.R.

    2008-01-01

    Advances in measurement techniques have made it possible to study dynamic changes in brain blood flow. Transcranial Doppler ultrasonography measures changes in cerebral blood flow-velocity in the larger cerebral arteries (e.g. the middle cerebral artery). Near infrared spectroscopy records changes in brain cortical tissue concentrations of hemoglobin. These techniques are non-invasive, and can be performed with the subject in supine, sitting or standing position. Together with photoplethysmog...

  13. Regional cerebral blood flow in schizophrenia

    International Nuclear Information System (INIS)

    Regional cerebral blood flow (rCBF) was measured at rest using the 133Xe inhalation technique in 40 DSM-III-diagnosed schizophrenics (22 males, 18 females: mean age 35.0 years, range 20-49 years) and 31 age-and sex-matched normal controls (16 males, 15 females: mean age 34.3 years, range 21-49 years). The absolute value (AV) and the percent value (PV) of the rCBF in schizophrenics were compared with those in controls. Correlations between rCBF and the Brief Psychiatric Rating Scale (BPRS) scores or the performance of Wisconsin Card Sorting Test (WCST) were examined in schizophrenics. Schizophrenics showed significantly lower AVs in all brain regions examined and a significantly lower PV in the left superior frontal region than controls. The hyperfrontal rCBF distribution which was found in both hemispheres in controls, was absent in the left hemisphere in schizophrenics. In schizophrenics, superior frontal blood flows were significantly negatively correlated with the negative symptom scores of the BPRS but not with the total scores and the positive symptom scores of the BPRS. In schizophrenics, inferior frontal blood flows were significantly correlated with the number of sorting categories achieved. These results indicate that rCBF in schizophrenia is reduced in the whole brain and especially in the left superior frontal region. These findings suggest a frontal lobe dysfunction in schizophrenia. (author)

  14. Laser Speckle Imaging of Cerebral Blood Flow

    Science.gov (United States)

    Luo, Qingming; Jiang, Chao; Li, Pengcheng; Cheng, Haiying; Wang, Zhen; Wang, Zheng; Tuchin, Valery V.

    Monitoring the spatio-temporal characteristics of cerebral blood flow (CBF) is crucial for studying the normal and pathophysiologic conditions of brain metabolism. By illuminating the cortex with laser light and imaging the resulting speckle pattern, relative CBF images with tens of microns spatial and millisecond temporal resolution can be obtained. In this chapter, a laser speckle imaging (LSI) method for monitoring dynamic, high-resolution CBF is introduced. To improve the spatial resolution of current LSI, a modified LSI method is proposed. To accelerate the speed of data processing, three LSI data processing frameworks based on graphics processing unit (GPU), digital signal processor (DSP), and field-programmable gate array (FPGA) are also presented. Applications for detecting the changes in local CBF induced by sensory stimulation and thermal stimulation, the influence of a chemical agent on CBF, and the influence of acute hyperglycemia following cortical spreading depression on CBF are given.

  15. A rat model of reproducible cerebral infarction using thrombotic blood clot emboli

    DEFF Research Database (Denmark)

    Overgaard, K.; Sereghy, T.; Boysen, G.; Pedersen, H.; Høyer, S.; Diemer, Nils Henrik

    Neuropathology, experimental thromboembolism, stroke, blood flow, in vitro thrombotic clotting, cerebral infarction, rat......Neuropathology, experimental thromboembolism, stroke, blood flow, in vitro thrombotic clotting, cerebral infarction, rat...

  16. A functional requirement for astroglia in promoting blood vessel development in the early postnatal brain.

    Directory of Open Access Journals (Sweden)

    Shang Ma

    Full Text Available Astroglia are a major cell type in the brain and play a key role in many aspects of brain development and function. In the adult brain, astrocytes are known to intimately ensheath blood vessels and actively coordinate local neural activity and blood flow. During development of the neural retina, blood vessel growth follows a meshwork of astrocytic processes. Several genes have also been implicated in retinal astrocytes for regulating vessel development. This suggests a role of astrocytes in promoting angiogenesis throughout the central nervous system. To determine the roles that astrocytes may play during brain angiogenesis, we employ genetic approaches to inhibit astrogliogenesis during perinatal corticogenesis and examine its effects on brain vessel development. We find that conditional deletion from glial progenitors of orc3, a gene required for DNA replication, dramatically reduces glial progenitor cell number in the subventricular zone and astrocytes in the early postnatal cerebral cortex. This, in turn, results in severe reductions in both the density and branching frequency of cortical blood vessels. Consistent with a delayed growth but not regression of vessels, we find neither significant net decreases in vessel density between different stages after normalizing for cortical expansion nor obvious apoptosis of endothelial cells in these mutants. Furthermore, concomitant with loss of astroglial interactions, we find increased endothelial cell proliferation, enlarged vessel luminal size as well as enhanced cytoskeletal gene expression in pericytes, which suggests compensatory changes in vascular cells. Lastly, we find that blood vessel morphology in mutant cortices recovers substantially at later stages, following astrogliosis. These results thus implicate a functional requirement for astroglia in promoting blood vessel growth during brain development.

  17. Effect of Body Temperature on the Radionuclide Evaluation of Cerebral Blood Flow

    International Nuclear Information System (INIS)

    Changes in regional cerebral blood flow (rCBF) may reflect physiological correlates of the disease state. In neuro-imaging studies, some diseases have frequently been reported to be associated with reduced or increased rCBF. In a previous study we had shown evidence of heat induced vasoconstriction of the carotid artery, which is the main vessel supplying blood to the brain. This vasoconstriction may lead to a decrease in cerebral blood flow in hyperthermic patients. Most radionuclide studies used to assess cerebral blood flow are routinely performed without taking into consideration patients' body temperature. In this regard it may be noted that results of radionuclide cerebral perfusion studies may be affected by hyperthermia, which could lead to false positive studies or misinterpretation of results when they are performed on patients suffering from various cerebrovascular diseases. The objective of the present study was to investigate the importance of body temperature and its effect on the results of radionuclide cerebral perfusion studies. Cerebral blood flow was assessed using Tc-99m hexamethylpropyleneamineoxime (Tc-99m HMPAO) imaging. Baseline scintigraphic images of the brain were obtained in 10 rabbits using a gamma camera equipped with a low energy parallel hole and high resolution collimator interfaced with a computer. Repeat brain studies were performed on the same rabbits at 3 and 6 days after raising the body temperature by 2 deg. C and 4 deg. C respectively using the same imaging protocol. The counts per pixel were determined on control and hyperthermia images. The uptake of Tc-99m HMPAO in the brain was found to be significantly reduced following hyperthermia implying reduction in blood flow. This decrease in cerebral perfusion appears to be variable from region to region, being more in the cerebral hemispheres, frontal areas (olfactory lobes) than in the cerebellum. Based on the results, the authors conclude that a rise in body temperature might

  18. Focal ischaemia caused by instability of cerebrovascular tone during attacks of hemiplegic migraine. A regional cerebral blood flow study

    DEFF Research Database (Denmark)

    Friberg, L; Olsen, T S; Roland, P E; Lassen, N A

    cerebral vessels (arterioles) alternating with a normal calibre for these vessels and/or short periods of vasodilatation. It isconsidered to be a primary pathological condition of the vessels. When vasoconstriction was present the blood flow decreased to values consistent with ischaemia, which was probably......During the course of hemiplegic migraine in 3 patients, changes in regional cerebral blood flow (rCBF) were recorded by the intracarotid 133Xe method and a 254 multidetector camera covering one hemisphere. The rCBF measurements were performed in conjunction with cerebral angiography. During...... patients developed transient motor and/or sensory deficits and subsequently severe headache. No signs of arterial occlusion were found. In the over and underperfused regions blood flow fluctuated rapidly because of instability of cerebrovascular tone, defined as transient constriction of the smallest...

  19. Small white matter lesion detection in cerebral small vessel disease

    Science.gov (United States)

    Ghafoorian, Mohsen; Karssemeijer, Nico; van Uden, Inge; de Leeuw, Frank E.; Heskes, Tom; Marchiori, Elena; Platel, Bram

    2015-03-01

    Cerebral small vessel disease (SVD) is a common finding on magnetic resonance images of elderly people. White matter lesions (WML) are important markers for not only the small vessel disease, but also neuro-degenerative diseases including multiple sclerosis, Alzheimer's disease and vascular dementia. Volumetric measurements such as the "total lesion load", have been studied and related to these diseases. With respect to SVD we conjecture that small lesions are important, as they have been observed to grow over time and they form the majority of lesions in number. To study these small lesions they need to be annotated, which is a complex and time-consuming task. Existing (semi) automatic methods have been aimed at volumetric measurements and large lesions, and are not suitable for the detection of small lesions. In this research we established a supervised voxel classification CAD system, optimized and trained to exclusively detect small WMLs. To achieve this, several preprocessing steps were taken, which included a robust standardization of subject intensities to reduce inter-subject intensity variability as much as possible. A number of features that were found to be well identifying small lesions were calculated including multimodal intensities, tissue probabilities, several features for accurate location description, a number of second order derivative features as well as multi-scale annular filter for blobness detection. Only small lesions were used to learn the target concept via Adaboost using random forests as its basic classifiers. Finally the results were evaluated using Free-response receiver operating characteristic.

  20. Dementia due to cerebral small vessel damage: Current ideas on its pathogenesis and therapy

    Directory of Open Access Journals (Sweden)

    I. V. Damulin

    2014-12-01

    Full Text Available Ever-increasing attention now focusses on dementia caused by small vessel damage when considering cerebrovascular disease leading to cognitive impairments (CIs. Stroke is one of the most important risk factors (RFs of vascular CI, including vascular dementia. Experienced stroke increases thrice the risk of dementia. Diffuse changes in the cerebral white matter (leukoaraiosis due to fluctuating blood pressure (BP and cerebral small vessel damage in most cases play an important role in the genesis of vascular CIs. Executive dysfunctions frequently concurrent with delayed psychomotor speed are the leading clinical manifestations of subcortical vascular dementia. Severe memory impairments are nottypical for subcortical dementia, its early stages in particular. The basis for the pathogenesis of CIs is the dissociation phenomenon that disrupts connections between the frontal lobes and subcortical structures and other cerebral cortical areas. Inadequate hypertension correction at a middle age is responsible for more than one fourth of cases of dementia developing in the elderly. The detection and further elimination of vascular RFs can reduce the risk of developing dementia in elderly and senile patients. Correction of elevated BP in the middle-aged is regarded as an effective method to prevent dementia in the future, but no premium is placed upon antihypertensive therapy in the elderly to lower elevated BP that is an inherent characteristic of this category of patients. Medications affecting RFs and those improving cerebral metabolism and bloodflow, including nicergoline are widely used to treat PD.

  1. Effect of prostaglandin E1 on cerebral blood flow in patients with chronic cerebral infarction

    International Nuclear Information System (INIS)

    The effect of prostaglandin E1 (PGE1) on cerebral blood flow (CBF) was studied in 10 patients with chronic cerebral infarction. Regional cerebral blood flow (rCBF) was measured by single photon emission computed tomography before and after they received PGE1 120 μg daily for 2 weeks. The rCBF of the brainstem, cerebellum, and frontal, temporal, and parietal lobes increased significantly after PGE1 administration. PGE1 also significantly increased the rCBF of the non-infarcted area adjacent to infarction. The results indicate that PGE1 increases the CBF of patients with chronic cerebral infarction without causing the intracerebral steal phenomenon. (author)

  2. Noninvasive method of estimating human newborn regional cerebral blood flow

    International Nuclear Information System (INIS)

    A noninvasive method of estimating regional cerebral blood flow (rCBF) in premature and full-term babies has been developed. Based on a modification of the 133Xe inhalation rCBF technique, this method uses eight extracranial NaI scintillation detectors and an i.v. bolus injection of 133Xe (approximately 0.5 mCi/kg). Arterial xenon concentration was estimated with an external chest detector. Cerebral blood flow was measured in 15 healthy, neurologically normal premature infants. Using Obrist's method of two-compartment analysis, normal values were calculated for flow in both compartments, relative weight and fractional flow in the first compartment (gray matter), initial slope of gray matter blood flow, mean cerebral blood flow, and initial slope index of mean cerebral blood flow. The application of this technique to newborns, its relative advantages, and its potential uses are discussed

  3. Regional cerebral blood flow in childhood headache

    International Nuclear Information System (INIS)

    Regional cerebral blood flow (rCBF) was measured in 16 cranial regions in 23 children and adolescents with frequent headaches using the non-invasive Xenon-133 inhalation technique. Blood flow response to 5% carbon dioxide (CO2) was also determined in 21 patients, while response to 50% oxygen was measured in the two patients with hemoglobinopathy. Included were 10 patients with a clinical diagnosis of migraine, 4 with musculoskeletal headaches, and 3 with features of both types. Also studied were 2 patients with primary thrombocythemia, 2 patients with hemoglobinopathy and headaches, 1 patient with polycythemia, and 1 with headaches following trauma. With two exceptions, rCBF determinations were done during an asymptomatic period. Baseline rCBF values tended to be higher in these young patients than in young adults done in our laboratory. Localized reduction in the expected blood flow surge after CO2 inhalation, most often noted posteriorly, was seen in 8 of the 13 vascular headaches, but in none of the musculoskeletal headache group. Both patients with primary thrombocythemia had normal baseline flow values and altered responsiveness to CO2 similar to that seen in migraineurs; thus, the frequently reported headache and transient neurologic signs with primary thrombocythemia are probably not due to microvascular obstruction as previously suggested. These data support the concept of pediatric migraine as a disorder of vasomotor function and also add to our knowledge of normal rCBF values in younger patients. Demonstration of altered vasomotor reactivity to CO2 could prove helpful in children whose headache is atypical

  4. Relationship between blood uric and acute cerebral infarction

    International Nuclear Information System (INIS)

    Objective: To study the relationship between blood uric acid and acute cerebral infarction. Methods: The level of blood uric acid and prevalence of hyperuricemia (HUA) were compared in 360 patients with acute cerebral infarction and 300 patients without it. According to the level of blood uric acid, 360 acute cerebral infarction patients were divided into HUA and normouricemia (NUA) groups. Age, sex, body mass index (BMI), blood glucose and total cholesterol were compared between the HUA and NUA group. The degree of neurological functional defection was compared between the two groups when patients were attacked by acute cerebral infarction. After a recovery treatment, the neurological functional defection of the two groups was compared a second time. Results: (1)The average blood uric acid level and prevalence of HUA were higher in patients with acute cerebral infarction. (2) The BMI, blood glucose and total cholesterol were higher in HUA group than in NUA group. (3) The neurological functional defection was more serious in HUA group when patients were attacked by acute cerebral infarction and after a recovery treatment. Conclusion: Hyperuricemia is related to acute cerebral infarction. (authors)

  5. Avian Blood-Vessel Formation in Space

    Science.gov (United States)

    Lelkes, Peter I.

    1999-01-01

    Based on previous studies, we hypothesized that the developmental anomalies observed in the past might be related to or caused by delayed or improper vascular development. The objective of our research is to test the hypothesis that exposure to microgravity during space flight cause delayed or improper vascular development during embryogenesis. The effects of microgravity on the time course and extent of avian blood-vessel formation are assessed using two models, one for angiogenesis and one for vasculogenesis. The methodological approach is dictated by the constraints of the tissue preservation method used in space. Thus, both in the chorioallantoic membrane (CAM) and in the adrenal, we will evaluate microscopically the vascular architecture and immunostain endothelial cells with specific antibodies (anti- vWF and QH1). The extent of ECM protein deposition will be assessed by immunohistochemistry and correlated with the degree of vascularization, using computer-based image analysis. Also, the cellular source for ECM proteins will be assessed by in situ hybridization.

  6. Tumour angiogenesis-Origin of blood vessels.

    Science.gov (United States)

    Krishna Priya, S; Nagare, R P; Sneha, V S; Sidhanth, C; Bindhya, S; Manasa, P; Ganesan, T S

    2016-08-15

    The conventional view of tumour vascularization is that tumours acquire their blood supply from neighbouring normal stroma. Additional methods of tumour vascularization such as intussusceptive angiogenesis, vasculogenic mimicry, vessel co-option and vasculogenesis have been demonstrated to occur. However, the origin of the endothelial cells and pericytes in the tumour vasculature is not fully understood. Their origin from malignant cells has been shown indirectly in lymphoma and neuroblastoma by immuno-FISH experiments. It is now evident that tumours arise from a small population of cells called cancer stem cells (CSCs) or tumour initiating cells. Recent data suggest that a proportion of tumour endothelial cells arise from cancer stem cells in glioblastoma. This was demonstrated both in vitro and in vivo. The analysis of chromosomal abnormalities in endothelial cells showed identical genetic changes to those identified in tumour cells. However, another report contradicted these results from the earlier studies in glioblastoma and had shown that CSCs give rise to pericytes and not endothelial cells. The main thrust of this review is the critical analysis of the conflicting data from different studies and the remaining questions in this field of research. The mechanism by which this phenomenon occurs is also discussed in detail. The transdifferentiation of CSCs to endothelial cells/pericytes has many implications in the progression and metastasis of the tumours and hence it would be a novel target for antiangiogenic therapy. PMID:26934471

  7. Silk fibroin microtubes for blood vessel engineering.

    Science.gov (United States)

    Lovett, Michael; Cannizzaro, Christopher; Daheron, Laurence; Messmer, Brady; Vunjak-Novakovic, Gordana; Kaplan, David L

    2007-12-01

    Currently available synthetic grafts demonstrate moderate success at the macrovascular level, but fail at the microvascular scale (inner diameter). We report on the development of silk fibroin microtubes for blood vessel repair with several advantages over existing scaffold materials/designs. These microtubes were prepared by dipping straight lengths of stainless steel wire into aqueous silk fibroin, where the addition of poly(ethylene oxide) (PEO) enabled control of microtube porosity. The microtube properties were characterized in terms of pore size, burst strength, protein permeability, enzymatic degradation, and cell migration. Low porosity microtubes demonstrated superior mechanical properties in terms of higher burst pressures, but displayed poor protein permeability; whereas higher porosity tubes had lower burst strengths but increased permeability and enhanced protein transport. The microtubes also exhibited cellular barrier functions as low porosity tubes prevented outward migration of GFP-transduced HUVECs, while the high porosity microtubes allowed a few cells per tube to migrate outward during perfusion. When combined with the biocompatible and suturability features of silk fibroin, these results suggest that silk microtubes, either implanted directly or preseeded with cells, are an attractive biomaterial for microvascular grafts. PMID:17727944

  8. Cerebral blood flow measurements using electron beam computed tomography (EBT)

    International Nuclear Information System (INIS)

    In close collaboration with the participants of the TEMPUS-Project Nr. 11117 a new technical and theoretical approach was developed to estimate cerebral blood flow using i.v. applied contrast agent and evaluating the cerebral time density curves using EBT as imaging method. This new approach and first clinical results are described. (author)

  9. Regional cerebral blood flow in neuropediatrics

    International Nuclear Information System (INIS)

    Single photon emission computed tomography can effectively and non-invasively measure regional blood flow. Mostly used 99mTc-HMPAO is a safe brain imaging agent for pediatric applications. The radiation dose is acceptable. Knowledge of the normal rCBF pattern, including normal asymmetries and variations due to age, is necessary prerequisite for the evaluation and reporting of the results of 99mTc-HMPAO brain SPECT studies in clinical practice. The interpretation of he rCBF study in a child requires knowledge of normal brain maturation. The aim of the present review is to focus on the contribution to clinical developmental neurology of SPECT The clinical use of SPECT in developmental neurology are epilepsy, brain death, acute neurological loss including stroke, language disorders, cerebral palsy, high-risk neonates, hypertension due to renovascular disease, traumatic brain injury, migraine, anorexia nervosa, autism, Gilles de la Tourette syndrome, attention deficit disorder-hyperactivity, and monitoring therapy. Sedation is not routinely used, rather each child is evaluated. However, drug sedation is mandatory in some uncooperative children. (author)

  10. Cerebral blood flow simulations in realistic geometries

    Directory of Open Access Journals (Sweden)

    Szopos Marcela

    2012-04-01

    Full Text Available The aim of this work is to perform the computation of the blood flow in all the cerebral network, obtained from medical images as angiographies. We use free finite elements codes as FreeFEM++. We first test the code on analytical solutions in simplified geometries. Then, we study the influence of boundary conditions on the flow and we finally perform first computations on realistic meshes. L’objectif est ici de simuler l’écoulement sanguin dans tout le réseau cérébral (artériel et veineux obtenu à partir d’angiographies cérébrales 3D à l’aide de logiciels d’éléments finis libres, comme FreeFEM++. Nous menons d’abord une étude détaillée des résultats sur des solutions analytiques et l’influence des conditions limites à imposer dans des géométries simplifiées avant de travailler sur les maillages réalistes.

  11. Effect of glycerol on cerebral blood flow in the cases of cerebral infarction in the chronic phase

    International Nuclear Information System (INIS)

    This report concerns the evaluation of the effects of glycerol for the treatment of cerebral infarction in the chronic phase. For this purpose, cerebral blood flow (CBF) was determined after glycerol loading in 19 patients, including 24 affected hemispheres. The mean global increase in CBF after glycerol infusion was 11.1%. The cases were classified into two groups: main trunk disease (Group A; occlusion or stenosis), and non-main trunk disease (Group B). Group A had a 6.4% decrease in CBF in the affected hemisphere and a 6.5% increase in the contralateral hemisphere. By contrast, the CBF of Group B increased by 20.2% and 14.8% in the affected and contralateral hemisphere, respectively. In the cases of cerebral infarction associated with main trunk disease, the functional reserve capacity of cerebral vessels may decrease significantly. Moreover, the steal phenomenon of CBF may occur in these cases after glycerol loading. Hence, glycerol infusion for the treatment of cerebral infarction in the chronic phase should be used with care, preferably after CBF measurements. (author)

  12. Cerebral blood flow velocity changes after rapid administration of surfactant.

    OpenAIRE

    Cowan, F.; Whitelaw, A; D. Wertheim; Silverman, M

    1991-01-01

    A computer linked Doppler system was used to make continuous measurements of cerebral blood flow velocity (CBFV) from the middle cerebral artery, mean arterial blood pressure (MAP) from the umbilical artery, and heart rate before, during, and for 20 minutes after the endotracheal administration of 200 mg/kg of porcine surfactant in 10 preterm infants with respiratory distress syndrome. Within two minutes of surfactant administration, there was a median fall of 6 mm Hg (15%) fall in MAP and 36...

  13. Instability and "Sausage-String" Appearance in Blood Vessels during High Blood Pressure

    CERN Document Server

    Alstrøm, P; Colding-Jorgensen, M; Gustafsson, F; Holstein-Rathlou, N H; Alstrom, Preben; Eguiluz, Victor M.; Colding-Jorgensen, Morten; Gustafsson, Finn; Holstein-Rathlou, Niels-Henrik

    1999-01-01

    A new Rayleigh-type instability is proposed to explain the `sausage-string' pattern of alternating constrictions and dilatations formed in blood vessels under influence of a vasoconstricting agent. Our theory involves the nonlinear elasticity characteristics of the vessel wall, and provides predictions for the conditions under which the cylindrical form of a blood vessel becomes unstable.

  14. Instability and `Sausage-String' Appearance in Blood Vessels during High Blood Pressure

    OpenAIRE

    Alstrøm, P.; Eguíluz, Víctor M.; Holstein-Rathlou, Niels-Henrik

    1998-01-01

    A new Rayleigh-type instability is proposed to explain the `sausage-string' pattern of alternating constrictions and dilatations formed in blood vessels under influence of a vasoconstricting agent. Our theory involves the nonlinear elasticity characteristics of the vessel wall, and provides predictions for the conditions under which the cylindrical form of a blood vessel becomes unstable.

  15. Distinct bone marrow blood vessels differentially regulate haematopoiesis.

    Science.gov (United States)

    Itkin, Tomer; Gur-Cohen, Shiri; Spencer, Joel A; Schajnovitz, Amir; Ramasamy, Saravana K; Kusumbe, Anjali P; Ledergor, Guy; Jung, Yookyung; Milo, Idan; Poulos, Michael G; Kalinkovich, Alexander; Ludin, Aya; Kollet, Orit; Shakhar, Guy; Butler, Jason M; Rafii, Shahin; Adams, Ralf H; Scadden, David T; Lin, Charles P; Lapidot, Tsvee

    2016-04-21

    Bone marrow endothelial cells (BMECs) form a network of blood vessels that regulate both leukocyte trafficking and haematopoietic stem and progenitor cell (HSPC) maintenance. However, it is not clear how BMECs balance these dual roles, and whether these events occur at the same vascular site. We found that mammalian bone marrow stem cell maintenance and leukocyte trafficking are regulated by distinct blood vessel types with different permeability properties. Less permeable arterial blood vessels maintain haematopoietic stem cells in a low reactive oxygen species (ROS) state, whereas the more permeable sinusoids promote HSPC activation and are the exclusive site for immature and mature leukocyte trafficking to and from the bone marrow. A functional consequence of high permeability of blood vessels is that exposure to blood plasma increases bone marrow HSPC ROS levels, augmenting their migration and differentiation, while compromising their long-term repopulation and survival. These findings may have relevance for clinical haematopoietic stem cell transplantation and mobilization protocols. PMID:27074509

  16. Lattice BGK Simulations of the Blood Flow in Elastic Vessels

    Institute of Scientific and Technical Information of China (English)

    LU Xiao-Yang; YI Hou-Hui; CHEN Ji-Yao; FANG Hai-Ping

    2006-01-01

    @@ The lattice Boltzmann method is applied to study the flow in elastic blood vessels. The volume-flow rate increases considerably when the compliance constant of the blood vessel is below a critical value. There is a region of the compliance constant in which the average volume-flow rate is dramatically enhanced. A harmonic perturbation of the pressure does not change the behaviour of the average volume-flow rate while the harmonic wave attenuates very quickly along the tube when the resonant period is close to that of the input wave. The model, together with the simulation results, is expected to be helpful to understand the mechanism of the blood volume-flow rate related to the compliance constant of the blood vessel, especially on the dependence of the flux of human blood vessel under weather changes, which has medical significance.

  17. Treatment for cerebral small vessel disease: effect of relaxin on the function and structure of cerebral parenchymal arterioles during hypertension

    OpenAIRE

    Chan, Siu-Lung; Sweet, Julie G.; Cipolla, Marilyn J.

    2013-01-01

    We investigated the effect of hypertension on the function and structure of cerebral parenchymal arterioles (PAs), a major target of cerebral small vessel disease (SVD), and determined whether relaxin is a treatment for SVD during hypertension. PAs were isolated from 18-wk-old female normotensive Wistar-Kyoto (WKY) rats, spontaneous hypertensive rats (SHRs), and SHRs treated with human relaxin 2 for 14 d (4 μg/h; n=8/group) and studied using a pressurized arteriograph system. Hypertension red...

  18. Effect of plasma exchange on blood viscosity and cerebral blood flow.

    OpenAIRE

    Brown, M M; Marshall, J

    1982-01-01

    The effects of plasma exchange using a low viscosity plasma substitute on blood viscosity and cerebral blood flow were investigated in eight subjects with normal cerebral vasculature. Plasma exchange resulted in significant reductions in plasma viscosity, whole blood viscosity, globulin and fibrinogen concentration without affecting packed cell volume. The reduction in whole blood viscosity was more pronounced at low shear rates suggesting an additional effect on red cell aggregation. Despite...

  19. Ischaemic cerebral infarction combined determination of regional cerebral blood flow and volume via SPECT

    International Nuclear Information System (INIS)

    A combined measurement of regional cerebral blood flow (r CBF) and volume (r CBV) by SPECT was performed in 15 patients with ischaemic cerebral infarction. For measurement of r CBF 99mTc-HMPAO was used, and for r CBV 99mTc-labelled red blood cells. Patients with acute or subacute cerebral infarction (n=10) showed elevation of r CBV whereas r CBF was either reduced or elevated. Patients with chronic cerebral infarction (n=5) showed reduction of both r CBF and R CBV. The combined measurement of both r CBF and r CBV by SPECT allows imaging and semiquantitative evaluation of haemodynamic changes in ischaemic cerebral infarction at various stages. The resulting data may be helpful in describing the pathophysiologic compensatory mechanisms. (orig.)

  20. 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.

  1. The role of blood vessels in high-resolution volume conductor head modeling of EEG.

    Science.gov (United States)

    Fiederer, L D J; Vorwerk, J; Lucka, F; Dannhauer, M; Yang, S; Dümpelmann, M; Schulze-Bonhage, A; Aertsen, A; Speck, O; Wolters, C H; Ball, T

    2016-03-01

    Reconstruction of the electrical sources of human EEG activity at high spatio-temporal accuracy is an important aim in neuroscience and neurological diagnostics. Over the last decades, numerous studies have demonstrated that realistic modeling of head anatomy improves the accuracy of source reconstruction of EEG signals. For example, including a cerebro-spinal fluid compartment and the anisotropy of white matter electrical conductivity were both shown to significantly reduce modeling errors. Here, we for the first time quantify the role of detailed reconstructions of the cerebral blood vessels in volume conductor head modeling for EEG. To study the role of the highly arborized cerebral blood vessels, we created a submillimeter head model based on ultra-high-field-strength (7T) structural MRI datasets. Blood vessels (arteries and emissary/intraosseous veins) were segmented using Frangi multi-scale vesselness filtering. The final head model consisted of a geometry-adapted cubic mesh with over 17×10(6) nodes. We solved the forward model using a finite-element-method (FEM) transfer matrix approach, which allowed reducing computation times substantially and quantified the importance of the blood vessel compartment by computing forward and inverse errors resulting from ignoring the blood vessels. Our results show that ignoring emissary veins piercing the skull leads to focal localization errors of approx. 5 to 15mm. Large errors (>2cm) were observed due to the carotid arteries and the dense arterial vasculature in areas such as in the insula or in the medial temporal lobe. Thus, in such predisposed areas, errors caused by neglecting blood vessels can reach similar magnitudes as those previously reported for neglecting white matter anisotropy, the CSF or the dura - structures which are generally considered important components of realistic EEG head models. Our findings thus imply that including a realistic blood vessel compartment in EEG head models will be helpful to

  2. Preventing pathological regression of blood vessels

    OpenAIRE

    Keshet, Eli

    2003-01-01

    Oxygen administration to premature infants suppresses retinal VEGF expression and results in the catastrophic vessel loss associated with retinopathy of prematurity. A study investigating the development of the retinal vasculature in mice (see related article on pages 50–57) demonstrates that specific activation of VEGF receptor-1 by placental growth factor-1 protects against oxygen-induced vessel loss without stimulating vascular proliferation and neovascularization.

  3. Cerebral blood flow: Physiologic and clinical aspects

    International Nuclear Information System (INIS)

    This book contains 46 chapters divided among nine sections. The section titles are: Historical Perspectives; Cerebrovascular Anatomy; Cerebrovascular Physiology; Methods of Clinical Measurement; Experimental Methods; Imaging of Cerebral Circulation; Cerebrovascular Pathophysiology; Cerebrovascular Pharmacology; and Surgical and Interventional Augmentation

  4. Development of a blood vessel searching device for HMS

    Science.gov (United States)

    Kuroda, Tatsuro; Uenoya, Toshiyuki; Tsuchiya, Kazuyoshi; Uetsuji, Yasutomo; Nakamachi, Eiji

    2007-12-01

    In this study, an automatic blood vessel searching system (BVSS) is newly developed, which is built in the health monitoring system (HMS) and the drug delivery system (DDS) to extract the blood, evaluates the blood sugar level and injects the insulin for the diabetic patients. Main subjects of our BVSS development are 1) a transmittance photo imaging of the finger by using the LED light as a near-infrared light source with peak wave length of 870 nm, and 2) an image processing to detect the location of the center of the blood vessel cross section. The sharp edge focus method was applied in our BVSS to detect the depth of blood vessel. We carried out experiments by using blood vessel phantoms, which consist of an artificial cylindrical blood vessel and skin tissue, which are made of the teflon tube and the silicone rubber. The teflon tube has the size of 0.6 mm in diameter and is filled with the human blood. The experimental results demonstrated that the estimated depth, which is obtained by image analysis corresponding to given depths, shows a good agreement with the real values, and consequently the availability of our BVSS is confirmed.

  5. Regional cerebral blood flow in focal cortical epilepsy

    DEFF Research Database (Denmark)

    Hougaard, Kristina Dupont; Oikawa, T; Sveinsdottir, E;

    1976-01-01

    Regional cerebral blood flow (rCBF) was studied in ten patients with focal cortical epilepsy. The blood flow was measured by the intra-arterial injection of xenon 133 (133Xe), and the isotope clearance was recorded by a multidetector scintillation camera with 254 detectors. Three patients were...

  6. Changes in mean cerebral blood flow velocity during cognitive task-induced cerebral fatigue in high performance fighter pilots

    Institute of Scientific and Technical Information of China (English)

    Yongsheng Chen

    2008-01-01

    BACKGROUND: Several studies have demonstrated that sustained cognitive tasks can induce cognitive fatigue and that the mean cerebral blood flow velocity changes in some cerebral regions during cerebral fatigue. OBJECTIVE: To dynamically monitor the changes in mean cerebral blood flow velocity in different brain regions of high performance fighter pilots during mental arithmetic tasks and consecutive performance tasks. DESIGN, TIME AND SETTING: The present neurophysiological trial, based on controlled observation, was performed at the Laboratory of Neurophysiology, Institute of Aviation Medicine, Air Force of China between January 2003 and December 2005. PARTICIPANTS: Forty-five males, high performance fighter pilots, averaging (27.6 ± 2.5) years, were recruited for this study. METHODS: The mean cerebral blood flow velocity in the anterior cerebral artery, middle cerebral artery, and posterior cerebral artery of subjects was dynamically tested using transcranial Doppler during 5- hour mental arithmetic tasks and during 5- hour consecutive performance tasks. The neurobehavioral ability index was analyzed throughout each trial according to the number of correct responses, false responses, and lost responses. Simultaneously, cerebral cognitive fatigue-induced lethargy was assessed by the Stanford Sleepiness Scale. MAIN OUTCOME MEASURES: Changes in mean cerebral blood flow velocity in the anterior cerebral artery, middle cerebral artery, and posterior cerebral artery; neurobehavioral ability index of mental arithmetic and consecutive performance tasks; Stanford Sleepiness Scale scores. RESULTS: During mental arithmetic tasks, the mean cerebral blood flow velocity in the anterior cerebral artery increased during hour 2 and decreased after hour 4. There was no significant change in mean cerebral blood flow velocity in the middle cerebral artery and posterior cerebral artery. During hour 4, cerebral cognitive fatigue was observed and, simultaneously, Stanford Sleepiness

  7. Relationship between blood pressure and cerebral blood flow during supine cycling: influence of aging.

    Science.gov (United States)

    Smirl, Jonathan D; Hoffman, Keegan; Tzeng, Yu-Chieh; Hansen, Alex; Ainslie, Philip N

    2016-03-01

    The cerebral pressure-flow relationship can be quantified as a high-pass filter, where slow oscillations are buffered (TFA) findings (altered phase or intact gain). This study aimed to determine whether these previous findings accurately represent this relationship. Both younger (20-30 yr; n = 10) and older (62-72 yr; n = 9) adults were examined. To enhance the signal-to-noise ratio, large oscillations in blood pressure (via oscillatory lower body negative pressure; OLBNP) were induced during steady-state moderate intensity supine exercise (∼45-50% of heart rate reserve). Beat-to-beat blood pressure, cerebral blood velocity, and end-tidal Pco2 were monitored. Very low frequency (0.02-0.07 Hz) and low frequency (0.07-0.20 Hz) range spontaneous data were quantified. Driven OLBNP point estimates were sampled at 0.05 and 0.10 Hz. The OLBNP maneuvers augmented coherence to >0.97 at 0.05 Hz and >0.98 at 0.10 Hz in both age groups. The OLBNP protocol conclusively revealed the cerebrovascular system functions as a high-pass filter during exercise throughout aging. It was also discovered that the older adults had elevations (+71%) in normalized gain (+0.46 ± 0.36%/%: 0.05 Hz) and reductions (-34%) in phase (-0.24 ± 0.22 radian: 0.10 Hz). There were also age-related phase differences between resting and exercise conditions. It is speculated that these age-related changes in the TFA metrics are mediated by alterations in vasoactive factors, sympathetic tone, or the mechanical buffering of the compliance vessels. PMID:26586907

  8. Quantitative measurement of total cerebral blood flow using 2D phase-contrast MRI and doppler ultrasound

    International Nuclear Information System (INIS)

    To compare of quantitative measurement of the total cerebral blood flow using two-dimensional phase-contrast MR imaging and Doppler ultrasound. In 16 volunteers (mean age, 26 years; mean body weight, 66 kg) without abnormal medical histories, two-dimensional phase-contrast MR imaging was performed at the level of the C2-3 inter vertebral disc for flow measurement of the internal carotid arteries and the vertebral arteries. Volume flow measurements using Doppler ultrasound were also performed at the internal carotid arteries 2cm above the carotid bifurcation, and at the vertebral arteries at the level of the upper pole of the thyroid gland. Flows in the four vessels measured by the two methods were compared using Wilcoxon's correlation analysis and the median score. Total cerebral blood flows were calculated by summing these four vessel flows, and mean values for the 16 volunteers were calculated. Cerebral blood flows measured by 2-D phase-contrast MR imaging and Doppler ultrasounds were 233 and 239 ml/min in the right internal carotid artery, 250 and 248 ml/min in the left internal carotid artery, 62 and 56 ml/min in the right vertebral artery, and 83 and 68 ml/min in the left vertebral artery. Correlation coefficients of the blood flows determined by the two methods were 0.48, 0.54, 0.49, and 0.62 in each vessel, while total cerebral blood flows were 628±68 (range, 517 to 779) ml/min and 612±79 (range, 482 to 804)ml/min, respectively. Total cerebral blood flow was easily measured using 2-D phase-contrast MR imaging and Doppler ultrasound, and the two noninvasive methods can therefore be used clinically for the measurement of total cerebral blood flow

  9. Cerebral blood flow and mental processes in schizophrenia.

    OpenAIRE

    Liddle, P F; Friston, K.J.; Frith, C D; Frackowiak, R S

    1992-01-01

    The patterns of cerebral blood flow associated with three syndromes of schizophrenic symptoms are compared with the loci of cerebral activation in normal subjects during the performance of mental processes implicated in the three syndromes. The psychomotor poverty syndrome, which has been shown to involve a diminished ability to generate words, is associated with decreased perfusion of the dorsolateral prefrontal cortex at a locus which is activated in normal subjects during the internal gene...

  10. Problems with cerebral blood flow measurement in man

    International Nuclear Information System (INIS)

    Measuring cerebral blood flow in man is usually thought to be of great physiological and pathological interest. Thus, since 30 years, attemps to quantify the cerebral blood flow have given rise to a growing field of research. But, none of the proposed methods has never been currently used as a means of diagnosis or as a test of cerebral function. Methodological and technical difficulties greatly account for this failure. First, a steady flow must be ensured, while measuring it. This requires the operator to keep lung ventilation and cerebral activity to a constant level. Second, the classical models, the stochastic or the compartimental one, imperfectly fit the clearance curves. The calculations based on these models involve systematic errors, specially with low flows. Third, no tracer has been found to quite satisfactory. 133Xe remains the most commonly used radiotracer. But its low solubility in vivo gives low cerebral count-rates. If the actual local partition coefficient is unknown, cerebral blood flow cannot be accurately quantified. Recently, positron emitters have been employed and their advantages begin to be exploited. The most reliable results have been obtained using an intracarotid injection. Finally, the characteristics of the detecting part of the stationary and tomographic systems vary greatly. But, till now, no study has shown what is the best compromise between good statistics and good spatial resolution

  11. Cerebral Blood Flow Autoregulation and Dysautoregulation.

    Science.gov (United States)

    Armstead, William M

    2016-09-01

    This article provides a review of cerebral autoregulation, particularly as it relates to the clinician scientist experienced in neuroscience in anesthesia and critical care. Topics covered are biological mechanisms; methods used for assessment of autoregulation; effects of anesthetics; role in control of cerebral hemodynamics in health and disease; and emerging areas, such as role of age and sex in contribution to dysautoregulation. Emphasis is placed on bidirectional translational research wherein the clinical informs the study design of basic science studies, which, in turn, informs the clinical to result in development of improved therapies for treatment of central nervous system conditions. PMID:27521192

  12. Regional cerebral blood flow autoregulation in patients with fulminant hepatic failure

    DEFF Research Database (Denmark)

    Larsen, Fin Stolze; Strauss, Gitte Irene; Møller, Kirsten;

    2000-01-01

    The absence of cerebral blood flow autoregulation in patients with fulminant hepatic failure (FHF) implies that changes in arterial pressure directly influence cerebral perfusion. It is assumed that dilatation of cerebral arterioles is responsible for the impaired autoregulation. Recently, fronta...

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

    DEFF Research Database (Denmark)

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

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

  14. Tracking blood vessels in human forearms using visual servoing

    DEFF Research Database (Denmark)

    Savarimuthu, Thiusius Rajeeth; Ellekilde, Lars-Peter; Hansen, Morten

    compensation. By using images taken with near-infrared light to locate the blood vessels in a human forearm and using the same images to detects movements of the arm, this paper shows that it is possible make a robot arm, potentially equipped with a needle for drawing the blood, compensate for the movements of...

  15. Evaluation of ocular acupuncture on cerebral infarction with cerebral blood flow perfusion imaging

    International Nuclear Information System (INIS)

    To evaluate the immediate effect of ocular acupuncture on patients, an method of SPECT image of cerebral blood flow daily stress test was established. 10 patients diagnosed as cerebral infarction by CT or MRI were tested. They all received 99Tcm-ECD SPECT imaging at twice before and after ocular acupuncture. By means of image subtraction technique and semi-quantitative method of regional interesting area, the change of regional cerebral blood flow was observed between the two images. Under restful state perfusion of cerebral blood flow in 18 foci was low at the frontal lobe, the cerebellum, the basal ganglia and temporal lobe. After ocular acupuncture, the perfusions were obviously increased in 16 foci among them and the reactivity of the frontal lobe and the cerebellum to ocular acupuncture was higher, the average improvement rate of which was 55.15% and 53.06% respectively, lower in the basal ganglia and temporal lobe, the average improvement rate was 31.79% and 36.67% respectively. 99Tcm-ECD SPECT cerebral perfusion image has some significant clinic value for evaluating the effect of ocular acupuncture to treating cerebral infarction. (authors)

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

    Science.gov (United States)

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

    2013-02-01

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

  17. DETECTION OF BLOOD VESSELS AND MEASUREMENT OF VESSEL WIDTH FOR DIABETIC RETINOPATHY

    Directory of Open Access Journals (Sweden)

    S.Sukanya

    2014-09-01

    Full Text Available The proposed method measures the retinal blood vessel diameter to identify arteriolar narrowing, arteriovenous (AV nicking, branching coefficients to detect early diabetic retinopathy. It utilizes the vessel centerline and edge information to measure the width for a vessel segment. From the input retinal image, the vascular network is extracted using the local entropy thresholding method. The vessel boundaries are extracted using sobel edge detection method. The skeletonization operation is applied to the vascular network and mapping the vessel boundaries and the skeleton image. The branching point detection method is then performed to localize all crossing locations. A rotational invariant mask to search the pixel pairs from the edge image, and calculate the shortest distance pair which provides the vessel width (or diameter for that cross-section. Variation in the width measurement identifies the diabetic retinopathy.

  18. Diet Induced Obesity Causes Cerebral Vessel Remodeling and Increases the Damage Caused by Ischemic Stroke

    OpenAIRE

    Deutsch, Christian; Portik-Dobos, Vera; Smith, Anita D; Ergul, Adviye; Dorrance, Anne M.

    2009-01-01

    Hypertension, elevated fasting blood glucose and plasma insulin develop in rats fed a high fat (HF) diet. Our goal was to assess the effects of obesity, beginning in childhood, on the adult cardiovascular system. We hypothesized that rats fed a HF diet would have larger ischemic cerebral infarcts and middle cerebral artery (MCA) remodeling. Three-week-old male Sprague Dawley rats were fed a HF (Obese) or control diet for 10 weeks. Cerebral ischemia was induced by MCA occlusion (MCAO). MCA str...

  19. Cerebral blood flow in asymptomatic individuals

    International Nuclear Information System (INIS)

    We studied the relationship between cortical grey matter flow (CBF) and age, cerebrovascular risk factors and the severity of subcortical hypersignals (HS, hyperintensity score in MRI) in 47 asymptomatic subjects with cerebrovascular risk factors. Multiple regression analysis revealed that HS was most strongly related to CBF, and that hematocrit, age and evidence of ischemic change detected in the electrocardiogram also appeared to be independent determinants of CBF. Both the severity and location of hypersignals were correlated with CBF. The most significant negative correlation observed was that between CBF and HS in the basal ganglia-thalamic region, where the degree of signal abnormality was modest. Decreased CBF in asymptomatic subjects with cerebrovascular risk factors may be related to microcirculatory disturbance associated with elevated hematocrit and an increase in the number of risk factors, and functional suppression of cerebral cortex due to the neuronal disconnection associated with subcortical lesions. In addition, impaired cerebral circulation may be related to MRI signal abnormalities. (author)

  20. Textile blood vessels coated with DLC

    Czech Academy of Sciences Publication Activity Database

    Jelínek, Miroslav; Podlaha, J.; Kocourek, Tomáš; Žížková, V.

    Berlin: Springer, 2009 - (Vander Sloten, J.; Verdonck, P.; Nyssen, M.; Haueisen, J.), s. 2173-2174. (IFMBE Proceedings. vol. 22). ISBN 978-3-540-89207-6. [ECIFMBE 2008. European Conference of the International Federation for Medical and Biological Engineering /4./. Antwerp (BE), 23.11.2008-27.11.2008] Institutional research plan: CEZ:AV0Z10100522 Keywords : PLD * DLC * vascular prostheses * in vivo * textile vessels Subject RIV: BH - Optics, Masers, Lasers http://dx.doi.org/10.1007/978-3-540-89208-3_519

  1. Changes of blood serum in acute cerebral infarction after treatment

    International Nuclear Information System (INIS)

    Objective: To investigate the changes of serum of HDL, LDL, TXB2, 6-K-PGF1α, TG and β-LP in acute cerebral infarction after treatment. Method: The serum levels of HDL, LDL, TXB2, 6-K-PGF1α, TG and β-LP in 94 acute cerebral infarction patients were detected by RIA and biochemistry assay respectively. Results: The results showed that the serum HDL and 6-K-PGF1α levels in acute cerebral infarction patients were increased (P2 were decreased (P<0.01) after treatment. Conclusion: The Hyper coagulable state and blood fat index in acute cerebral infarction after treatment could improve obviously. (authors)

  2. 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 and...... 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...

  3. Heritability of retinal vessel diameters and blood pressure

    DEFF Research Database (Denmark)

    Taarnhøj, Nina C B B; Larsen, Michael; Sander, Birgit;

    2006-01-01

    , aged 20 to 46 years, interpolated diameter estimates for the central retinal artery (CRAE), the central retinal vein (CRVE), and the artery-to-vein diameter ratio (AVR) were assessed by analysis of digital gray-scale fundus photographs of right eyes. RESULTS: The heritability was 70% (95% CI: 54...... for CRVE, and 0.67 +/- 0.05 microm for AVR. No significant influence on artery or vein diameters was found for gender, smoking, body mass index (BMI), total cholesterol, fasting blood glucose, or 2-hour oral glucose tolerance test values. CONCLUSIONS: In healthy young adults with normal blood pressure...... and blood glucose, variations in retinal blood vessel diameters and blood pressure were predominantly attributable to genetic effects. A genetic influence may have a role in individual susceptibility to hypertension and other vascular diseases. The results suggest that retinal vessel diameters and the...

  4. The effect of ventricular assist devices on cerebral blood flow and blood pressure fractality

    International Nuclear Information System (INIS)

    Biological signals often exhibit self-similar or fractal scaling characteristics which may reflect intrinsic adaptability to their underlying physiological system. This study analysed fractal dynamics of cerebral blood flow in patients supported with ventricular assist devices (VAD) to ascertain if sustained modifications of blood pressure waveform affect cerebral blood flow fractality. Simultaneous recordings of arterial blood pressure and cerebral blood flow velocity using transcranial Doppler were obtained from five cardiogenic shock patients supported by VAD, five matched control patients and five healthy subjects. Computation of a fractal scaling exponent (α) at the low-frequency time scale by detrended fluctuation analysis showed that cerebral blood flow velocity exhibited 1/f fractal scaling in both patient groups (α = 0.95 ± 0.09 and 0.97 ± 0.12, respectively) as well as in the healthy subjects (α = 0.86 ± 0.07). In contrast, fluctuation in blood pressure was similar to non-fractal white noise in both patient groups (α = 0.53 ± 0.11 and 0.52 ± 0.09, respectively) but exhibited 1/f scaling in the healthy subjects (α = 0.87 ± 0.04, P < 0.05 compared with the patient groups). The preservation of fractality in cerebral blood flow of VAD patients suggests that normal cardiac pulsation and central perfusion pressure changes are not the integral sources of cerebral blood flow fractality and that intrinsic vascular properties such as cerebral autoregulation may be involved. However, there is a clear difference in the fractal scaling properties of arterial blood pressure between the cardiogenic shock patients and the healthy subjects

  5. Cerebral autoregulation control of blood flow in the brain

    CERN Document Server

    Payne, Stephen

    2016-01-01

    This Brief provides a comprehensive introduction to the control of blood flow in the brain. Beginning with the basic physiology of autoregulation, the author goes on to discuss measurement techniques, mathematical models, methods of analysis, and relevant clinical conditions, all within this single volume. The author draws together this disparate field, and lays the groundwork for future research directions. The text gives an up-to-date review of the state of the art in cerebral autoregulation, which is particularly relevant as cerebral autoregulation moves from the laboratory to the bedside. Cerebral Autoregulation will be useful to researchers in the physical sciences such as mathematical biology, medical physics, and biomedical engineering whose work is concerned with the brain. Researchers in the medical sciences and clinicians dealing with the brain and blood flow, as well as industry professionals developing techniques such as ultrasound, MRI, and CT will also find this Brief of interest.

  6. OBSERVATIONS ON VASCULAR PATTERN OF CHORIONIC BLOOD VESSELS OF PLACENTA

    Directory of Open Access Journals (Sweden)

    Yousuf Sarwar

    2013-10-01

    Full Text Available ABSTRACT: BACKGROUND: Placenta is a choriodecidual structure develops during pregnancy implanted on the uterine wall and car ries vital functions. It is connected to the foetus through umbilical cord. The branches of umbilical vessels that traverse along foetal surface of placenta are referred as chorionic vessels. There are two different patterns of chorionic vessels – Dispersa l and Magistral. In the dispersal type, the umbilical vessels undergo successive divisions with gradually diminishing caliber towards periphery while in magistral pattern the vessels traverse to the edge of placenta without appreciable decrease in diameter of vessels. The present study has been done for visualization of the pattern of chorionic vessels in placenta obtained from labour room of a tertiary care hospital in eastern Bihar, India. MATERIALS AND METHODS: A total of one hundred and fifty (150 fres h and intact placenta of full term pregnancies collected from Obstetrics & Gynaecology department were included in the study. After washing with distilled water, removal of blood clots were done with slight digital pressure applied over arteries and vein a nd later on by irrigation with saline. The cut end of the umbilical cord was carefully visualized to identify the umbilical arteries and vein. Dye was injected into umbilical vessels under normal physiological pressure and diameter of chorionic blood vesse ls were taken at the center and periphery. Ultimately each vessel was followed and examined to observe the dispersal and magistral pattern of chorionic blood vessels of placenta. RESULTS AND CONCLUSION: Out of the total of one hundred and fifty (150 full term placenta obtained and examined in the Anatomy department during the study period, 64% Dispersal type & 36 % of Magistral type of arterial pattern of branching of chorionic vessels were observed. Vein and its tributaries presented Dispersal pattern in 60% and Magistral pattern in 40%. There is a significant

  7. Customizable engineered blood vessels using 3D printed inserts.

    Science.gov (United States)

    Pinnock, Cameron B; Meier, Elizabeth M; Joshi, Neeraj N; Wu, Bin; Lam, Mai T

    2016-04-15

    Current techniques for tissue engineering blood vessels are not customizable for vascular size variation and vessel wall thickness. These critical parameters vary widely between the different arteries in the human body, and the ability to engineer vessels of varying sizes could increase capabilities for disease modeling and treatment options. We present an innovative method for producing customizable, tissue engineered, self-organizing vascular constructs by replicating a major structural component of blood vessels - the smooth muscle layer, or tunica media. We utilize a unique system combining 3D printed plate inserts to control construct size and shape, and cell sheets supported by a temporary fibrin hydrogel to encourage cellular self-organization into a tubular form resembling a natural artery. To form the vascular construct, 3D printed inserts are adhered to tissue culture plates, fibrin hydrogel is deposited around the inserts, and human aortic smooth muscle cells are then seeded atop the fibrin hydrogel. The gel, aided by the innate contractile properties of the smooth muscle cells, aggregates towards the center post insert, creating a tissue ring of smooth muscle cells. These rings are then stacked into the final tubular construct. Our methodology is robust, easily repeatable and allows for customization of cellular composition, vessel wall thickness, and length of the vessel construct merely by varying the size of the 3D printed inserts. This platform has potential for facilitating more accurate modeling of vascular pathology, serving as a drug discovery tool, or for vessel repair in disease treatment. PMID:26732049

  8. Effect of pregnancy on regional cerebral blood flow

    International Nuclear Information System (INIS)

    Regional cerebral blood flow (r-CBF) of 10 pregnant women were quantified by 133Xe SPECT study with inhalation method before and after artificial abortion. During pregnancy, value of r-CBF in each region except occipital lobe was significantly higher than that of the post abortion. Arterial blood gas was analyzed after SPECT procedure. Pco2 concentration increased significantly after artificial abortion. Although its mechanism is unknown, our preliminary work demonstrates that r-CBF increased by pregnancy. (author)

  9. Ozone Therapy on Cerebral Blood Flow: A Preliminary Report

    Directory of Open Access Journals (Sweden)

    Bernardino Clavo

    2004-01-01

    Full Text Available Ozone therapy is currently being used in the treatment of ischemic disorders, but the underlying mechanisms that result in successful treatment are not well known. This study assesses the effect of ozone therapy on the blood flow in the middle cerebral and common carotid arteries. Seven subjects were recruited for the therapy that was performed by transfusing ozone-enriched autologous blood on 3 alternate days over 1 week. Blood flow quantification in the common carotid artery (n = 14 was performed using color Doppler. Systolic and diastolic velocities in the middle cerebral artery (n = 14 were estimated using transcranial Doppler. Ultrasound assessments were conducted at the following three time points: 1 basal (before ozone therapy, 2 after session #3 and 3 1 week after session #3. The common carotid blood flow had increased by 75% in relation to the baseline after session #3 (P < 0.001 and by 29% 1 week later (P = 0.039. In the middle cerebral artery, the systolic velocity had increased by 22% after session #3 (P = 0.001 and by 15% 1 week later (P = 0.035, whereas the diastolic velocity had increased by 33% after session #3 (P < 0.001 and by 18% 1 week later (P = 0.023. This preliminary Doppler study supports the clinical experience of achieving improvement by using ozone therapy in peripheral ischemic syndromes. Its potential use as a complementary treatment in cerebral low perfusion syndromes merits further clinical evaluation.

  10. Regional cerebral blood flow studies in patients with pituitary tumours

    International Nuclear Information System (INIS)

    Regional cerebral blood flow (rCBF) was measured in seven patients with pituitary tumours, in one patient with a craniopharyngioma, and in one patient with an empty sella; rCB was increased only in patients with gonadotrophin deficiency. The preliminary conclusion is that this is perhaps related to the pituitary tumour itself, and in particular to the endocrine state. (author)

  11. Regional cerebral blood flow in primary degenerative dementia

    International Nuclear Information System (INIS)

    Regional cerebral blood flow (rCBF) was examined, using SPECT by Xe-133 inhalation, in patients with primary degenerative dementia who were subgrouped according to predominant symptoms with respect to amnesia, apraxia, agnosia, aphasia, and personality changes. Also the effect of sex and age at dementia onset on the rCBF patterns was assessed. (author). 26 refs.; 1 fig.; 7 tabs

  12. Cerebral blood flow in patients with dementia of Alzheimer's type

    DEFF Research Database (Denmark)

    Postiglione, A; Lassen, N A; Holman, B L

    1993-01-01

    In the normal brain as well as in Alzheimer's disease (AD), regional cerebral blood flow (CBF) is coupled to metabolic demand and, therefore, changes in CBF reflect variations in neuronal metabolism. The use of radionuclide techniques, such as positron emission tomography (PET) and single photon...

  13. Longitudinal Cerebral Blood Flow Changes during Speech in Hereditary Ataxia

    Science.gov (United States)

    Sidtis, John J.; Strother, Stephen C.; Naoum, Ansam; Rottenberg, David A.; Gomez, Christopher

    2010-01-01

    The hereditary ataxias constitute a group of degenerative diseases that progress over years or decades. With principal pathology involving the cerebellum, dysarthria is an early feature of many of the ataxias. Positron emission tomography was used to study regional cerebral blood flow changes during speech production over a 21 month period in a…

  14. Electromechanical Model of Blood Flow in Vessels

    OpenAIRE

    Ivo Cap; Barbora Czippelova

    2008-01-01

    The present paper deals with some theoretical derivations connected with very efficient method of solution of hydrodynamic problems of blood flow in human cardiovascular system. The electromechanical analogy of liquid flow in a tube and electromagnetic wave propagating along an electric transmission line is discussed. We have derived a detailed circuit-like model of an elementary section of the elastic tube with viscose Newtonian liquid. The analogy harmonic current electrical cir...

  15. Electromechanical Model of Blood Flow in Vessels

    Directory of Open Access Journals (Sweden)

    Ivo Cap

    2008-01-01

    Full Text Available The present paper deals with some theoretical derivations connected with very efficient method of solution of hydrodynamic problems of blood flow in human cardiovascular system. The electromechanical analogy of liquid flow in a tube and electromagnetic wave propagating along an electric transmission line is discussed. We have derived a detailed circuit-like model of an elementary section of the elastic tube with viscose Newtonian liquid. The analogy harmonic current electrical circuit has been designed

  16. Performance Analysis of Retinal Image Blood Vessel Segmentation

    Directory of Open Access Journals (Sweden)

    D.Siva Sundhara Raja

    2014-06-01

    Full Text Available The retinal image diagnosis is an important methodology for diabetic retinopathy detection and analysis. in this paper, the morphological operations and svm classifier are used to detect and segment the blood vessels from the retinal image. the proposed system consists of three stages-first is preprocessing of retinal image to separate the green channel and second stage is retinal image enhancement and third stage is blood vessel segmentation using morphological operations and svm classifier. the performance of the proposed system is analyzed using publicly available dataset.

  17. Blood Vessel Segmentation of Fundus Images by Major Vessel Extraction and Subimage Classification.

    Science.gov (United States)

    Roychowdhury, Sohini; Koozekanani, Dara D; Parhi, Keshab K

    2015-05-01

    This paper presents a novel three-stage blood vessel segmentation algorithm using fundus photographs. In the first stage, the green plane of a fundus image is preprocessed to extract a binary image after high-pass filtering, and another binary image from the morphologically reconstructed enhanced image for the vessel regions. Next, the regions common to both the binary images are extracted as the major vessels. In the second stage, all remaining pixels in the two binary images are classified using a Gaussian mixture model (GMM) classifier using a set of eight features that are extracted based on pixel neighborhood and first and second-order gradient images. In the third postprocessing stage, the major portions of the blood vessels are combined with the classified vessel pixels. The proposed algorithm is less dependent on training data, requires less segmentation time and achieves consistent vessel segmentation accuracy on normal images as well as images with pathology when compared to existing supervised segmentation methods. The proposed algorithm achieves a vessel segmentation accuracy of 95.2%, 95.15%, and 95.3% in an average of 3.1, 6.7, and 11.7 s on three public datasets DRIVE, STARE, and CHASE_DB1, respectively. PMID:25014980

  18. Morphological changes of cerebral vessels and expression patterns of MMP-2 and MMP-9 on cerebrovascular wall of alcoholic rats.

    Science.gov (United States)

    Qi, Qian; Liu, Xia; Zhang, Guozhong; He, Wenjing; Ma, Rufei; Cong, Bin; Li, Yingmin

    2014-01-01

    Alcohol abuse increases the incidence of cerebral accidents, which correlates with cerebrovascular structural changes. The present study was designed to observe the cerebrovascular remodeling of drinking rats with light microscopy and transmission electron microscopy (TEM). Short-term alcohol administration induced apparent amplification of perivascular spaces around small vessels in brain tissue, while long-term administration caused pathological changes of basilar arteries (BAs), including endothelial exfoliation, inner elastic lamina (IEL) fragmentation and thickening of tunica media and adventitia. In addition, the relationship between cerebrovascular remodeling and MMP-2 and MMP-9 synthesized by endothelial cells and vascular smooth muscle cells was explored by immunohistochemistry. The two protein expression in cerebral vessels changed dynamically, peaking at 1-2 weeks after treatment, and decreasing as treatment continued. These results suggest that MMP-2 and MMP-9 may play a significant role in blood-brain barrier disruption after alcohol abuse. But the chronic changes of cerebral arteries resulted from drinking are not coincident with time course of MMP-2 and MMP-9 expression in situ. PMID:24966898

  19. Acrolein generation stimulates hypercontraction in isolated human blood vessels

    International Nuclear Information System (INIS)

    Increased risk of vasospasm, a spontaneous hyperconstriction, is associated with atherosclerosis, cigarette smoking, and hypertension-all conditions involving oxidative stress, lipid peroxidation, and inflammation. To test the role of the lipid peroxidation- and inflammation-derived aldehyde, acrolein, in human vasospasm, we developed an ex vivo model using human coronary artery bypass graft (CABG) blood vessels and a demonstrated acrolein precursor, allylamine. Allylamine induces hypercontraction in isolated rat coronary artery in a semicarbazide-sensitive amine oxidase activity (SSAO) dependent manner. Isolated human CABG blood vessels (internal mammary artery, radial artery, saphenous vein) were used to determine: (1) vessel responses and sensitivity to acrolein, allylamine, and H2O2 exposure (1 μM-1 mM), (2) SSAO dependence of allylamine-induced effects using SSAO inhibitors (semicarbazide, 1 mM; MDL 72274-E, active isomer; MDL 72274-Z, inactive isomer; 100 μM), (3) the vasoactive effects of two other SSAO amine substrates, benzylamine and methylamine, and (4) the contribution of extracellular Ca2+ to hypercontraction. Acrolein or allylamine but not H2O2, benzylamine, or methylamine stimulated spontaneous and pharmacologically intractable hypercontraction in CABG blood vessels that was similar to clinical vasospasm. Allylamine-induced hypercontraction and blood vessel SSAO activity were abolished by pretreatment with semicarbazide or MDL 72274-E but not by MDL 72274-Z. Allylamine-induced hypercontraction also was significantly attenuated in Ca2+-free buffer. In isolated aorta of spontaneously hypertensive rat, allylamine-induced an SSAO-dependent contraction and enhanced norepinephrine sensitivity but not in Sprague-Dawley rat aorta. We conclude that acrolein generation in the blood vessel wall increases human susceptibility to vasospasm, an event that is enhanced in hypertension

  20. Earley changes in cerebral blood flow following head exposure of rabbit at a mean absorbed dose of 1000 rads

    International Nuclear Information System (INIS)

    Observations were made on 5 animals after 12 head exposures. The local cerebral blood flow increased on the 1st hour and lasted during the following 15-20 h. Two particular responses were used to test cerebral vasotonicity: rate increases due to inhalation of CO2 (5 p. cent CO2 in air) and accompanying paradoxical sleep. Their decrease after irradiation was studied systematically by CO2 tests whatever the rate level reached. These weaker increases were not the indication of an upper limit of the the rate, they also occurred when the rate fell back to its initial value. They appeared on the 2nd hour and lasted till the 48th hour. As a conclusion: head irradiation resulted in an early increase of cerebral blood flow lasting less than 24 h; the pattern of metabolic or myogenic regulation of intraparenchymatous vessels and neurogenic regulation of extraparenchymatous vessels would explain the observed phenomena better. The metabolic modifications of the irradiated tissue should result in vasodilation of intraparenchymatous vessels. The stimulating action of the neurovegetative centers would be shown by a decrease of the vessel responses to CO2 at the level of the extraparenchymatous vessels

  1. FCM Based Blood Vessel Segmentation Method for Retinal Images

    Directory of Open Access Journals (Sweden)

    Nilanjan Dey

    2012-06-01

    Full Text Available Segmentation of blood vessels in retinal images providesearly diagnosis of diseases like glaucoma, diabeticretinopathy and macular degeneration. Among thesediseases occurrence of Glaucoma is most frequent and hasserious ocular consequences that can even lead toblindness, if it is not detected early. The clinical criteria forthe diagnosis of glaucoma include intraocular pressuremeasurement, optic nerve head evaluation, retinal nervefiber layer and visual field defects. This form of bloodvessel segmentation helps in early detection for ophthalmicdiseases, and potentially reduces the risk of blindness.The low-contrast images at the retina owing to narrowblood vessels of the retina are difficult to extract. Theselow contrast images are, however useful in revealingcertain systemic diseases. Motivated by the goals ofimproving detection of such vessels, this present workproposes an algorithm for segmentation of blood vessels,and compares the results between expert ophthalmologists’hand-drawn ground-truths and segmented image (i.e. theoutput of the present work. Sensitivity, specificity, positivepredictive value (PPV, positive likelihood ratio (PLR andaccuracy are used to evaluate overall performance. It isfound that this work segments blood vessels successfullywith sensitivity, specificity, PPV, PLR and accuracy of99.62%, 54.66%, 95.08%, 219.72 and 95.03%,respectively.

  2. Cerebral blood flow links insulin resistance and baroreflex sensitivity.

    Science.gov (United States)

    Ryan, John P; Sheu, Lei K; Verstynen, Timothy D; Onyewuenyi, Ikechukwu C; Gianaros, Peter J

    2013-01-01

    Insulin resistance confers risk for diabetes mellitus and associates with a reduced capacity of the arterial baroreflex to regulate blood pressure. Importantly, several brain regions that comprise the central autonomic network, which controls the baroreflex, are also sensitive to the neuromodulatory effects of insulin. However, it is unknown whether peripheral insulin resistance relates to activity within central autonomic network regions, which may in turn relate to reduced baroreflex regulation. Accordingly, we tested whether resting cerebral blood flow within central autonomic regions statistically mediated the relationship between insulin resistance and an indirect indicator of baroreflex regulation; namely, baroreflex sensitivity. Subjects were 92 community-dwelling adults free of confounding medical illnesses (48 men, 30-50 years old) who completed protocols to assess fasting insulin and glucose levels, resting baroreflex sensitivity, and resting cerebral blood flow. Baroreflex sensitivity was quantified by measuring the magnitude of spontaneous and sequential associations between beat-by-beat systolic blood pressure and heart rate changes. Individuals with greater insulin resistance, as measured by the homeostatic model assessment, exhibited reduced baroreflex sensitivity (b = -0.16, p mediated by cerebral blood flow in central autonomic regions, including the insula and cingulate cortex (mediation coefficients < -0.06, p-values < .01). Activity within the central autonomic network may link insulin resistance to reduced baroreflex sensitivity. Our observations may help to characterize the neural pathways by which insulin resistance, and possibly diabetes mellitus, relates to adverse cardiovascular outcomes. PMID:24358272

  3. Cerebral blood flow links insulin resistance and baroreflex sensitivity.

    Directory of Open Access Journals (Sweden)

    John P Ryan

    Full Text Available Insulin resistance confers risk for diabetes mellitus and associates with a reduced capacity of the arterial baroreflex to regulate blood pressure. Importantly, several brain regions that comprise the central autonomic network, which controls the baroreflex, are also sensitive to the neuromodulatory effects of insulin. However, it is unknown whether peripheral insulin resistance relates to activity within central autonomic network regions, which may in turn relate to reduced baroreflex regulation. Accordingly, we tested whether resting cerebral blood flow within central autonomic regions statistically mediated the relationship between insulin resistance and an indirect indicator of baroreflex regulation; namely, baroreflex sensitivity. Subjects were 92 community-dwelling adults free of confounding medical illnesses (48 men, 30-50 years old who completed protocols to assess fasting insulin and glucose levels, resting baroreflex sensitivity, and resting cerebral blood flow. Baroreflex sensitivity was quantified by measuring the magnitude of spontaneous and sequential associations between beat-by-beat systolic blood pressure and heart rate changes. Individuals with greater insulin resistance, as measured by the homeostatic model assessment, exhibited reduced baroreflex sensitivity (b = -0.16, p < .05. Moreover, the relationship between insulin resistance and baroreflex sensitivity was statistically mediated by cerebral blood flow in central autonomic regions, including the insula and cingulate cortex (mediation coefficients < -0.06, p-values < .01. Activity within the central autonomic network may link insulin resistance to reduced baroreflex sensitivity. Our observations may help to characterize the neural pathways by which insulin resistance, and possibly diabetes mellitus, relates to adverse cardiovascular outcomes.

  4. Characteristics of global cerebral ischemia models constructed by modified four-vessel occlusion in rats

    Institute of Scientific and Technical Information of China (English)

    Jinbao Li; Lai Jiang; Hua Xu; Yuanchang Xiong; Xiaoming Deng

    2006-01-01

    (n =15): ischemia 15 minutes and reperfusion 180 minutes. ② Preparation of the model of global cerebral ischemia: Four-vessel occlusion- induced global cerebral ischemia rat models were modified, I.e. Bilateral vertebral arteries could be electrocauterized and blocked, and bilateral common carotid arteries were enclosed with 10-0 suture loosely. On the second day, keeping the animal awake, the suture was tightened and kept tense to block the blood flow of bilateral common carotid artery. After certain duration of ischemia, the suture was cut off and drawn out, thus the reperfusion of bilateral common carotid artery was resumed. ③Observation of physiological indexes: VSM hemodynamic monitor and temperature monitor (Thermal ert TH-5,U.S.A) were used to record and measure the changes of blood pressure, rectal temperature, brain temperature ,arterial blood gas and other physiological indexes of the rats in the control group before, 5 and 15 minutes after ischemia and 10,30,60,120 and 180 minutes after reperfusion. ④Preparation of brain tissue pathological samples: Except for ischemia control group, rats of other groups were anesthetized and their brain tissues were harvested and subjected to haematoxylin and eosin staining at 72 hours after reperfusion. ⑤ Evaluation of pathological change of brain tissue: The coronal plane of anterior commissure of cerebrum was used to evaluate corpora striatum, and the coronal plane of anterior hippocampus was used to evaluate hippocampal CA1/2 region, CA3 region and CA4 region, subiculum, superior pyramidal lobe and inferior pyramidal lobe of dentate gyrus as well as neocortex. Irreversible neuronal damage included pyknotic cells with eosinophilic cytoplasm and trachychromatic nucleus, homogenous cytoplasm and naked nucleus. Neurons without the above changes were considered to be normal. The number of normal neurons in the above-mentioned brain regions was counted under the microscope. MAIN OUTCOME MEASURES: ① The changes of

  5. History of International Society for Cerebral Blood Flow and Metabolism

    DEFF Research Database (Denmark)

    Paulson, Olaf B; Kanno, Iwao; Reivich, Martin;

    2012-01-01

    dealing with CBF and metabolism were arranged, and the fast growing research led to a demand for a specialized journal. In this scientific environment, the International Society for Cerebral Blood Flow and Metabolism (ISCBFM) and its official Journal of Cerebral Metabolism were established in 1981 and has...... grown within the society and is now an integrated part. The ISCBFM is a sound society, and support of young scientists is among its goals. Several awards have been established. Other activities including summer schools, courses, satellite meetings, and Gordon conferences have contributed to the success...

  6. Enlarged perivascular spaces and cerebral small vessel disease

    OpenAIRE

    Potter, Gillian M; Doubal, Fergus N; Jackson, Caroline A; Chappell, Francesca M; Sudlow, Cathie L; Dennis, Martin S; Wardlaw, Joanna M.

    2013-01-01

    Background and aims Enlarged perivascular spaces (also known as Virchow–Robin spaces) on T2-weighted brain magnetic resonance imaging are common, but their etiology, and specificity to small vessel as opposed to general cerebrovascular disease or ageing, is unclear. We tested the association between enlarged perivascular spaces and ischemic stroke subtype, other markers of small vessel disease, and common vascular risk factors. Methods We prospectively recruited patients with acute stroke, di...

  7. Effects of midazolam on cerebral blood flow in human volunteers

    International Nuclear Information System (INIS)

    The effects of intravenously administered midazolam on cerebral blood flow were evaluated in eight healthy volunteers using the 133Xe inhalation technique. Six minutes after an intravenous dose of 0.15 mg/kg midazolam, the cerebral blood flow decreased significantly (P less than 0.001) from a value of 40.6 +/- 3.3 to a value of 27.0 +/- 5.0 ml . 100 g-1 . min-1. Cerebrovascular resistance (CVR) increased from 2.8 +/- 0.2 to 3.9 to 0.6 mmHg/(ml . 100 g-1 . min-1)(P less than 0.001). Mean arterial blood pressure decreased significantly (P less than 0.05) from 117 +/- 8 to 109 +/- 9 mmHg and arterial carbon dioxide tension increased from 33.9 +/- 2.3 to 38.6 +/- 3.2 mmHg (P less than 0.05). Arterial oxygen tension remained stable throughout the study, 484 +/- 95 mmHg before the administration of midazolam and 453 +/- 76 mmHg after. All the subjects slept after the injection of the drug and had anterograde amnesia of 24.5 +/- 5 min. The decrease in mean arterial blood pressure was probably not important since it remained in the physiologic range for cerebral blood flow autoregulation. The increase in arterial carbon dioxide tension observed after the midazolam injection may have partially counteracted the effect of this new benzodiazepine on cerebral blood flow. Our data suggest that midazolam might be a safe agent to use for the induction of anethesia in neurosurgical patients with intracranial hypertension

  8. Retinal Blood Vessel Segmentation with Optic Disc Pixels Exclusion

    Directory of Open Access Journals (Sweden)

    Randy Cahya Wihandika

    2013-06-01

    Full Text Available The morphological changes of retinal blood vessels are important indicators used to diagnose and monitor the progression of various diseases. A number of retinal blood vessel segmentation methods have been introduced, including the line operator based methods, which have shown satisfactory results. However, the basic line operator method cannot discriminate the pixels around the retinal optic disc, resulting in false classification of those pixels. In this paper, we integrate the detection of pixels around the retinal optic disc to the line operator method so that those pixels can be excluded from the vessel pixels. The method is evaluated on the widely used retinal dataset, the DRIVE dataset. The results demonstrate that the proposed method has made improvements over the basic and the multi-scale line detector with accuracy and area under curve of 0.942 and 0.9521, respectively.

  9. Method and arrangement for angiography of blood vessels

    International Nuclear Information System (INIS)

    A method and apparatus for angiography in which information contained within multiple serial images of contrast medium flowing through a blood vessel is combined to form a single image having improved vessel edge delineation. More specifically, a method is disclosed whereby a contrast medium opaque to X-rays is injected into a blood vessel distant from an artery section of interest, preferably injected into a vein, whereby the contrast medium is mixed with blood prior to its passing through the artery section. Multiple X-ray images are obtained as the contrast medium and blood mixture flows through the artery section. These multiple images are registered with respect to each other according to a landmark contained within the patient, the landmark having a predetermined relationship to the vessel of interest. The landmark could be a bone, catheter or any other material opaque to X-rays. Density measurements are made with respect to each corresponding image segment or element of the multiple images and are combined to synthesize a composite image. The synthesized image has an edge uncertainty equal to that of one of the individual images. (Auth.)

  10. Blood vessel segmentation for neck and head computed tomography angiography

    OpenAIRE

    Hedblom, Anders

    2013-01-01

    This thesis presents tests and discussions evaluating different methods for doing automatic or semi automatic blood vessel segmentation on single CT data volumes of the head and neck. The two approaches being closest to accomplish this are a bone subtracting registration process, and a more advanced region growing combined with morphology.

  11. The Conditions of Vibrations and Collapse of Human Blood Vessels

    Czech Academy of Sciences Publication Activity Database

    Hemza, J.; Chlup, Hynek; Maršík, František

    Liberec : Technical University of Liberec, 2010 - (Čapek, L.), s. 98-102 ISBN 978-80-7372-648-5. [Human Biomechanics 2010. Sychrov (CZ), 04.10.2010-06.10.2010] Institutional research plan: CEZ:AV0Z20760514 Keywords : viscoelastic properties of human blood vessels * bridging vein * neo-Hooks materialmodel Subject RIV: JJ - Other Materials

  12. Vessel Elasticity Estimation by Normalized Blood Pressure Dynamics

    Czech Academy of Sciences Publication Activity Database

    Jurák, Pavel; Halámek, Josef; Vondra, Vlastimil; Leinveber, Pavel; Plachý, M.; Fráňa, P.; Souček, M.; Kára, T.

    Tel-Aviv : Israel Heart Society, 2008. s. 115. ISBN N. [IDSS 2008 - International Dead Sea Symposium on Cardiac Arrhythmias and Device Therapy /9./. 22.09.2008-24.09.2008, Tel-Aviv] Institutional research plan: CEZ:AV0Z20650511 Keywords : hypertension * vessel compliance * blood pressure * dynamic parameters Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery

  13. Study of cerebral blood flow in patients with cerebral infarction by 133Xe inhalation method

    International Nuclear Information System (INIS)

    Cerebral blood flow in both hemispheres was studied by the Xe-133 inhalation method in 49 patients with cerebral infarction in the unilateral hemisphere. They were classified into three groups by computed tomographic findings as follows: relatively large low density lesion including the cerebral cortex and subcortex (group I), relatively large low density lesion including the subcortical white matter and basal ganglia (group II), and small low density lesion including the subcortical white matter (group III). Mean cerebral blood flow (mCBF) in the affected hemisphere was markedly low in group I, moderately low in group II, and slightly low in group III. Several cases in groups I and II revealed remarkable changes of mCBF within one month after the onset. The mCBF in both hemispheres was lower in group I than in groups II and III within one week after the onset. Seven to 12 weeks later, mCBF was lower in the affected hemisphere than in the unaffected one in groups I and II: This was lower when compared with that in group III. There was almost no difference in mCBF between the affected and unaffected hemispheres in group III. Sequential changes of mCBF in both hemispheres were divided into 7 types in reevaluable 27 patients. Sequential changes of mCBF in both hemispheres of the patients with cerebral infarction were considered to be caused mainly by recanalization and hemorrhagic infarction. (J.P.N.)

  14. Gene expression analysis in human breast cancer associated blood vessels.

    Directory of Open Access Journals (Sweden)

    Dylan T Jones

    Full Text Available Angiogenesis is essential for solid tumour growth, whilst the molecular profiles of tumour blood vessels have been reported to be different between cancer types. Although presently available anti-angiogenic strategies are providing some promise for the treatment of some cancers it is perhaps not surprisingly that, none of the anti-angiogenic agents available work on all tumours. Thus, the discovery of novel anti-angiogenic targets, relevant to individual cancer types, is required. Using Affymetrix microarray analysis of laser-captured, CD31-positive blood vessels we have identified 63 genes that are upregulated significantly (5-72 fold in angiogenic blood vessels associated with human invasive ductal carcinoma (IDC of the breast as compared with blood vessels in normal human breast. We tested the angiogenic capacity of a subset of these genes. Genes were selected based on either their known cellular functions, their enriched expression in endothelial cells and/or their sensitivity to anti-VEGF treatment; all features implicating their involvement in angiogenesis. For example, RRM2, a ribonucleotide reductase involved in DNA synthesis, was upregulated 32-fold in IDC-associated blood vessels; ATF1, a nuclear activating transcription factor involved in cellular growth and survival was upregulated 23-fold in IDC-associated blood vessels and HEX-B, a hexosaminidase involved in the breakdown of GM2 gangliosides, was upregulated 8-fold in IDC-associated blood vessels. Furthermore, in silico analysis confirmed that AFT1 and HEX-B also were enriched in endothelial cells when compared with non-endothelial cells. None of these genes have been reported previously to be involved in neovascularisation. However, our data establish that siRNA depletion of Rrm2, Atf1 or Hex-B had significant anti-angiogenic effects in VEGF-stimulated ex vivo mouse aortic ring assays. Overall, our results provide proof-of-principle that our approach can identify a cohort of

  15. Cerebral blood flow asymmetries in headache-free migraineurs

    International Nuclear Information System (INIS)

    Regional cerebral blood flow (rCBF) asymmetries were studied in controls and patients with common and classic/complicated migraine using 133Xe inhalation with 8 homologously situated external collimators over each cerebral hemisphere. Migraine patients as a group more frequently had posterior rCBF asymmetries than controls (p less than 0.03). Although there were no differences in the number of anterior rCBF asymmetries, migraine patients had 2 or more asymmetric probe pairs more often than controls (p less than 0.02). The posterior rCBF asymmetries, consistent with the site of activation of many migraine attacks, may be related to more labile control of the cerebral circulation

  16. Studies of cerebral atrophy and regional cerebral blood flow in patients with Parkinson's disease

    International Nuclear Information System (INIS)

    Cerebral atrophy and regional cerebral blood flow (rCBF) of 25 patients with Parkinson's disease were studied. The rCBF was measured with the intra-arterial Xe-133 injection method. The results obtained were as follows: 1) Sixty four % of Parkinson's disease patients showed ventricular dilation, and 76% of Parkinson's disease patients showed cortical atrophy on the CT scan, but we had to allow for the effects of the natural aging process on these results. 2) No correlation was recognized either between cerebral atrophy and the severity of Parkinson's disease, or between cerebral atrophy and the duration of Parkinson's disease. 3) In Parkinson's disease patients, the mean rCBF was lower than that of normal control subjects. The difference was even more remarkable in older patients. Only 40% of Parkinson's disease patients showed hyperfrontal pattern. 4) There was no correlation either between the mean rCBF and the severity of Parkinson's disease, or between the mean rCBF and the duration of Parkinson's disease. There was no significant difference between the mean rCBF of Parkinson's disease patients receiving levodopa and that of untreated patients. 5) The mean rCBF decreased in patients with cerebral atrophy on the CT scan. 6) Parkinson's disease patients with intellectual impairment showed cerebral atrophy and a remarkable decrease of the mean rCBF. 7) The effect of aging on cerebral atrophy on the CT scan had to be allowed for, but judging from the decrease of the mean rCBF, the cerebral cortex is evidently involved in Parkinson's disease. 8) The rCBF decline in Parkinson's disease patients may be related with the diminished cortical metabolic rate due to a remote effect of striatal dysfunction and a disturbance of mesocortical dopaminergic pathways. (J.P.N.)

  17. Regional cerebral blood flow in fibromyalgia

    International Nuclear Information System (INIS)

    Full text: Little is known of the aetiology of fibromyalgia (FM), a condition diagnosed on the basis of widespread chronic pain and multiple tender points. We have used Tc-99m HMPAO SPECT to compare regional cerebral bloodflow (rCBF) in 17 women who fulfill American College of Rheumatology criteria for FM to 22 age, sex and education matched controls. Both Statistical Parametric Mapping (SPM95) and coregistered MRI guided ROI were used for analysis. SPM95 revealed statistically significant hypoperfusion in the pontine tegmentum (p=0.048) and a trend to hypoperfusion in the left putamen (p=0.07). MRI guided ROI placement by an operator blinded to clinical information and the coregistered SPECT images, confirmed significant hypoperfusion of the left thalamus (p<0.0001) and the pontine tegmentum (p=0.001) and revealed trends towards hypoperfusion in the caudate nuclei and right thalamus. These results are consistent with the hypothesis that FM is due to dysfunction of central pain pathways. Spinothalamic neurones are known to be involved in pain perception and there are synapse connections to the thalamus in the gigantocellular part of the medulla and pons

  18. Regional cerebral blood flow in fibromyalgia

    Energy Technology Data Exchange (ETDEWEB)

    Kwiatek, R.; Barnden, L.; Rowe, C.; McKinnon, J.; Pile, K. [The Queen Elizabeth Hospital , Adelaide, SA (Australia)

    1998-06-01

    Full text: Little is known of the aetiology of fibromyalgia (FM), a condition diagnosed on the basis of widespread chronic pain and multiple tender points. We have used Tc-99m HMPAO SPECT to compare regional cerebral bloodflow (rCBF) in 17 women who fulfill American College of Rheumatology criteria for FM to 22 age, sex and education matched controls. Both Statistical Parametric Mapping (SPM95) and coregistered MRI guided ROI were used for analysis. SPM95 revealed statistically significant hypoperfusion in the pontine tegmentum (p=0.048) and a trend to hypoperfusion in the left putamen (p=0.07). MRI guided ROI placement by an operator blinded to clinical information and the coregistered SPECT images, confirmed significant hypoperfusion of the left thalamus (p<0.0001) and the pontine tegmentum (p=0.001) and revealed trends towards hypoperfusion in the caudate nuclei and right thalamus. These results are consistent with the hypothesis that FM is due to dysfunction of central pain pathways. Spinothalamic neurones are known to be involved in pain perception and there are synapse connections to the thalamus in the gigantocellular part of the medulla and pons

  19. Intensive blood pressure control affects cerebral blood flow in type 2 diabetes mellitus patients

    DEFF Research Database (Denmark)

    Kim, Yu-Sok; Davis, Shyrin C A T; Truijen, Jasper;

    2011-01-01

    Type 2 diabetes mellitus is associated with microvascular complications, hypertension, and impaired dynamic cerebral autoregulation. Intensive blood pressure (BP) control in hypertensive type 2 diabetic patients reduces their risk of stroke but may affect cerebral perfusion. Systemic hemodynamic...... variables and transcranial Doppler-determined cerebral blood flow velocity (CBFV), cerebral CO2 responsiveness, and cognitive function were determined after 3 and 6 months of intensive BP control in 17 type 2 diabetic patients with microvascular complications (T2DM+), in 18 diabetic patients without (T2DM...... groups. However, in contrast to nondiabetic hypertensive patients, intensive BP control reduced CBFV in T2DM- (58±9 to 54±12 cm · s-1) and T2DM+ (57±13 to 52±11 cm · s-1) at 3 months, but CBFV returned to baseline at 6 months only in T2DM-, whereas the reduction in CBFV progressed in T2DM+ (to 48±8 cm...

  20. Measurement of regional cerebral blood flow by positron emission tomography

    International Nuclear Information System (INIS)

    The principal advantage of positron emission tomography over other methods for measuring cerebral blood flow stems from the accurate, quantitative three-dimensional measurements of regional brain radioactivity that are possible with this technique. As a result, accurate quantitative measurements of regional cerebral blood flow can be obtained for both superficial and deep cerebral structures. The value of PET for investigating central nervous system physiology and pathology extends far beyond this, however. Through the use of different radiotracers and appropriate mathematical models, PET can be applied to the measurement of a wide variety of physiologic variables. Measurements of rCBF tell only part of the story. Experience with PET and with a variety of other techniques has taught us that rCBF is at times a poor indicator of the metabolic, functional, and biochemical status of cerebral tissue. It is only by understanding the interaction of all of these factors that our understanding of neurologic disease can advance. It is in the investigation of these complex relationships that the real value of PET resides

  1. Regional cerebral blood flow in SPECT pattern in Parkinson's disease

    International Nuclear Information System (INIS)

    The purpose of our work was to compare the regional cerebral blood flow (rCBF) in SPECT examination in Parkinson's disease with (17 cases) and without (7 cases) dementia and in various clinical stages of the disease. The patients underwent SPECT examination 5-40 min after intravenous application of HMPAO (Ceretec, Amersham) with 740 Mbq (20 mCi) pertechnate 99mTc. SPECT was performed with a Siemens Diacam single-head rotating gamma camera coupled to a high resolution collimator and Icon computer system provided by the manufacturer. The results were defined in relative values of ROI in relation to cerebellum. Patients with Parkinson's disease showed hypoperfusion in cerebral lobes and in deep cerebral structures including the basal ganglia. Regional perfusion deficit in SPECT was seen with and without associated dementia and already in early stage of the disease. Parkinson's disease is provoked by the lesions of dopaminergic neurons of the central nervous system leading to domination of extrapyramidal symptoms. There are many indications that also the neurotransmitters associated with cognitive functions as acetylcholine demonstrate some abnormalities. However, only in some cases of Parkinson's disease dementia is the dominating symptom. Our results of regional cerebral blood flow testify that in Parkinson's disease the dysfunction of the central nervous system is more diffuse than has previously been suggested. (author)

  2. The effect of phenylephrine on arterial and venous cerebral blood flow in healthy subjects

    DEFF Research Database (Denmark)

    Ogoh, Shigehiko; Sato, Kohei; Fisher, James P; Seifert, Thomas; Overgaard, Morten; Secher, Niels H

    2011-01-01

    Sympathetic regulation of the cerebral circulation remains controversial. Although intravenous phenylephrine (PE) infusion reduces the near-infrared spectroscopy (NIRS)-determined measure of frontal lobe oxygenation (S(c) O(2) ) and increases middle cerebral artery mean blood velocity (MCA V(mean......(mean) ), suggesting α-adrenergic-mediated cerebral vasoconstriction, this remains unconfirmed by evaluation of arterial and venous cerebral blood flow.......Sympathetic regulation of the cerebral circulation remains controversial. Although intravenous phenylephrine (PE) infusion reduces the near-infrared spectroscopy (NIRS)-determined measure of frontal lobe oxygenation (S(c) O(2) ) and increases middle cerebral artery mean blood velocity (MCA V...

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

    Science.gov (United States)

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

    2005-04-01

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

  4. Middle cerebral artery blood velocity and plasma catecholamines during exercise

    DEFF Research Database (Denmark)

    Pott, F; Jensen, K; Hansen, H;

    1996-01-01

    . Vmean increased by 31 +/- 3% and 48 +/- 4%, respectively, and this was significantly higher compared to handgrip (P < 0.05). During maximal cycling, plasma adrenaline increased from 0.21 +/- 0.04 nmol L-1 at rest to 4.18 +/- 1.46 nmol L-1, and noradrenaline increased from 0.79 +/- 0.08 to 12.70 +/- 1......During dynamic exercise, mean blood velocity (Vmean) in the middle cerebral artery (MCA) demonstrates a graded increase to work rate and reflects regional cerebral blood flow. At a high work rate, however, vasoactive levels of plasma catecholamines could mediate vasoconstriction of the MCA and...... thereby elevate Vmean at a given volume flow. To evaluate transcranial Doppler-determined Vmean at high plasma catecholamine levels, seven elite cyclists performed a maximal performance test on a bicycle ergometer. Results were compared with those elicited during five incremental exercise bouts and during...

  5. Disparity in regional cerebral blood flow during electrically induced seizure

    DEFF Research Database (Denmark)

    Sestoft, D; Meden, P; Hemmingsen, R; Hancke, B; Madsen, P L; Friberg, L

    1993-01-01

    This is a presentation of 2 cases in which the intraictal regional cerebral blood flow distribution was measured with the 99mTc-HMPAO single photon emission computerized tomography technique during an electrically induced seizure. Although the seizure was verified as generalized on electroencepha......This is a presentation of 2 cases in which the intraictal regional cerebral blood flow distribution was measured with the 99mTc-HMPAO single photon emission computerized tomography technique during an electrically induced seizure. Although the seizure was verified as generalized on...... electroencephalography, the regional neuronal activity expressed as rCBF unexpectedly was markedly asymmetrical in one of the cases. These findings demonstrated that the 99mTc-HMPAO technique makes it possible to discriminate intraictal variation in cortical and subcortical activation between the hemispheres during...

  6. Cerebral blood flow mapping in children with sickle cell disease

    International Nuclear Information System (INIS)

    A cerebral blood flow mapping system was applied to the evaluation of cerebral blood flow (CBF) in 21 patients with sickle cell cerebrovascular disease, by means of a Picker xenon computed tomographic (CT) scanner. Results indicate that (1) xenon CT is a safe and reliable procedure in children with cerebrovascular diseases; (2) CBF in the gray matter of children seems to be higher than in previously reported data obtained with use of isotopes; and (3) regional CBF can be altered significantly by changing the size of the region of interest (ROI). The term regional CBF probably has to be carefully defined in xenon CT flow mapping. Correlation with anatomy by means of CT or magnetic resonance imaging and comparison with the ROI of the contralateral side and/or adjacent sections is important

  7. Determination of cerebral blood flow with the EMI CT scanner

    International Nuclear Information System (INIS)

    Cerebral blood flow (CBF) determinations were made in seven baboons and two patients with the EMI CT dedicated head scanner. The method for determining the CBF was tested and measurements were made during physiological states elicited by changes in pCO2 and depth of anaesthesia. The method has a number of advantages, particularly for assessing CBF responses to pCO2 changes. (author)

  8. CEREBRAL BLOOD FLOW AND METABOLISM IN ANXIETY AND ANXIETY DISORDERS

    OpenAIRE

    Mathew, Roy J.

    1994-01-01

    Anxiety disorders are some of the commonest psychiatric disorders and anxiety commonly co-exists with other psychiatric conditions. Anxiety can also be a normal emotion. Thus, study of the neurobiological effects of anxiety is of considerable significance. In the normal brain, cerebral blood flow (CBF) and metabolism (CMR) serve as indices of brain function. CBF/CMR research is expected to provide new insight into alterations in brain function in anxiety disorders and other psychiatric disord...

  9. Mathematical modeling of patient-specific ventricular assist device implantation to reduce particulate embolization rate to cerebral vessels.

    Science.gov (United States)

    Ricardo Argueta-Morales, I; Tran, Reginald; Ceballos, Andres; Clark, William; Osorio, Ruben; Divo, Eduardo A; Kassab, Alain J; DeCampli, William M

    2014-07-01

    Stroke is the most devastating complication after ventricular assist device (VAD) implantation, with an incidence of 14%-47% despite improvements in device design and anticoagulation. This complication continues to limit the widespread implementation of VAD therapy. Patient-specific computational fluid dynamics (CFD) analysis may elucidate ways to reduce this risk. A patient-specific three-dimensional model of the aortic arch was generated from computed tomography. A 12 mm VAD outflow-graft (VAD-OG) "anastomosed" to the aorta was rendered. CFD was applied to study blood flow patterns. Particle tracks, originating from the VAD, were computed with a Lagrangian phase model and percentage of particles entering the cerebral vessels was calculated. Twelve implantation configurations of the VAD-OG and three particle sizes (2, 4, and 5 mm) were considered. Percentage of particles entering the cerebral vessels ranged from 6% for the descending aorta VAD-OG anastomosis, to 14% for the ascending aorta at 90 deg VAD-OG anastomosis. Values were significantly different among all configurations (X(2) = 3925, p < 0.0001). Shallower and more cephalad anastomoses prevented formation of zones of recirculation in the ascending aorta. In this computational model and within the range of anatomic parameters considered, the percentage of particles entering the cerebral vessels from a VAD-OG is reduced by nearly 60% by optimizing outflow-graft configuration. Ascending aorta recirculation zones, which may be thrombogenic, can also be eliminated. CFD methods coupled with patient-specific anatomy may aid in identifying the optimal location and angle for VAD-OG anastomosis to minimize stroke risk. PMID:24441718

  10. Decreased cerebral blood flow after administration of sodium bicarbonate in the distressed newborn infant

    DEFF Research Database (Denmark)

    Lou, H C; Lassen, N A; Fris-Hansen, B

    1978-01-01

    In the course of our studies on cerebral blood flow in newborn infants, we have observed a striking depressing effect of sodium bicarbonate infusion on cerebral blood flow which in some cases may severely aggravate cerebral ischemia. We measured cerebral blood flow before and after the treatment...... with 1 to 8 meqs of sodium bicarbonate in seven distressed newborn infants. The 133 Xe clearance technique was used. The results showed in six of the seven cases a decrease in cerebral blood flow, which in most cases was reduced to 14 to 22 ml/100 g/min, which is about half the value prior to the...

  11. Endothelial dysfunction is associated with the severity of cerebral small vessel disease.

    Science.gov (United States)

    Nezu, Tomohisa; Hosomi, Naohisa; Aoki, Shiro; Kubo, Satoshi; Araki, Mutsuko; Mukai, Tomoya; Takahashi, Tetsuya; Maruyama, Hirofumi; Higashi, Yukihito; Matsumoto, Masayasu

    2015-04-01

    The pathogenesis of cerebral small vessel disease, a disease that involves white matter lesions (WMLs) and cerebral microbleeds (CMBs), is thought to be associated with endothelial dysfunction. Flow-mediated dilation (FMD) has been used to measure endothelium-dependent vasodilation. The aim of this study was to investigate the association between endothelial function (as measured by FMD) and cerebral small vessel disease. Patients with a history of cerebrovascular disease and comorbidities were enrolled in this study (n=102; 69 males, 70.1±9.2 years). The patients were divided into two groups according to the severity of WMLs, which were assessed by Fazekas classification; grades 0 to 1 as mild WMLs group and grades 2 to 3 as severe WMLs group. A gradient-echo MRI was performed in 96 patients (94.1%) to evaluate whether CMBs were present. The patients in the severe WMLs group (n=40) were older (P=0.001), more frequently exhibited hypertension (P=0.045) and diabetes mellitus (P=0.026) and possessed lower FMD values (PFMD cutoff values for predicting the presence of severe WMLs and CMBs were 3.9% and 3.7%, respectively. On multivariate logistic analysis, FMD FMD dysfunction as evaluated by FMD may be predictive of the severity of cerebral small vessel disease. PMID:25672660

  12. Aging, regional cerebral blood flow, and neuropsychological functioning

    International Nuclear Information System (INIS)

    Previous studies found changes in regional cerebral blood flow (rCBF) patterns related to both age and various cognitive tasks. However, no study has yet demonstrated a relationship between rCBF and performance on the Luria-Nebraska Neuropsychological Battery (LNNB) in an elderly group. Seventy-nine elderly volunteers (56-88 years old), both healthy and demented, underwent the 133xenon inhalation rCBF procedure and were given the LNNB. The decrements in the gray-matter blood flow paralleled decrements in performance on the LNNB. Using partial correlations, a significant proportion of shared variance was observed between gray-matter blood flow and the LNNB scales. However, there was much less of a relationship between white-matter blood flow and performance on the LNNB. This study suggests that even within a restricted age sample rCBF is related in a global way to neuropsychological functioning

  13. Aging, regional cerebral blood flow, and neuropsychological functioning

    Energy Technology Data Exchange (ETDEWEB)

    MacInnes, W.D.; Golden, C.J.; Gillen, R.W.; Sawicki, R.F.; Quaife, M.; Uhl, H.S.; Greenhouse, A.J.

    1984-10-01

    Previous studies found changes in regional cerebral blood flow (rCBF) patterns related to both age and various cognitive tasks. However, no study has yet demonstrated a relationship between rCBF and performance on the Luria-Nebraska Neuropsychological Battery (LNNB) in an elderly group. Seventy-nine elderly volunteers (56-88 years old), both healthy and demented, underwent the /sup 133/xenon inhalation rCBF procedure and were given the LNNB. The decrements in the gray-matter blood flow paralleled decrements in performance on the LNNB. Using partial correlations, a significant proportion of shared variance was observed between gray-matter blood flow and the LNNB scales. However, there was much less of a relationship between white-matter blood flow and performance on the LNNB. This study suggests that even within a restricted age sample rCBF is related in a global way to neuropsychological functioning.

  14. Investigation on artificial blood vessels prepared from bacterial cellulose.

    Science.gov (United States)

    Zang, Shanshan; Zhang, Ran; Chen, Hua; Lu, Yudong; Zhou, Jianhai; Chang, Xiao; Qiu, Guixing; Wu, Zhihong; Yang, Guang

    2015-01-01

    BC (bacterial cellulose) exhibits quite distinctive properties than plant cellulose. The outstanding properties make BC a promising material for preparation of artificial blood vessel. By taking advantage of the high oxygen permeability of PDMS (polydimethylsiloxane) as a tubular template material, a series of BC tubes with a length of 100 mm, a thickness of 1mm and an outer diameter of 4 or 6mm were biosynthesized with the help of Gluconacetobacter xylinum. Through characterization by SEM (scanning electron microscope), tensile testing and thermal analysis, it is demonstrated that BC tubes are good enough for artificial blood vessel with elaborated nano-fiber architecture, qualified mechanical properties and high thermal stability. In addition, measurement of biocompatibility also shows that BC tubes are greatly adaptable to the in vivo environment. The results indicate that BC tubes have great potential for being utilized as tubular scaffold materials in the field of tissue engineering. PMID:25491966

  15. Blood Vessel-Derived Acellular Matrix for Vascular Graft Application

    Directory of Open Access Journals (Sweden)

    Luigi Dall’Olmo

    2014-01-01

    Full Text Available To overcome the issues connected to the use of autologous vascular grafts and artificial materials for reconstruction of small diameter (<6 mm blood vessels, this study aimed to develop acellular matrix- (AM- based vascular grafts. Rat iliac arteries were decellularized by a detergent-enzymatic treatment, whereas endothelial cells (ECs were obtained through enzymatic digestion of rat skin followed by immunomagnetic separation of CD31-positive cells. Sixteen female Lewis rats (8 weeks old received only AM or previously in vitro reendothelialized AM as abdominal aorta interposition grafts (about 1 cm. The detergent-enzymatic treatment completely removed the cellular part of vessels and both MHC class I and class II antigens. One month after surgery, the luminal surface of implanted AMs was partially covered by ECs and several platelets adhered in the areas lacking cell coverage. Intimal hyperplasia, already detected after 1 month, increased at 3 months. On the contrary, all grafts composed by AM and ECs were completely covered at 1 month and their structure was similar to that of native vessels at 3 months. Taken together, our findings show that prostheses composed of AM preseeded with ECs could be a promising approach for the replacement of blood vessels.

  16. Investigation on artificial blood vessels prepared from bacterial cellulose

    International Nuclear Information System (INIS)

    BC (bacterial cellulose) exhibits quite distinctive properties than plant cellulose. The outstanding properties make BC a promising material for preparation of artificial blood vessel. By taking advantage of the high oxygen permeability of PDMS (polydimethylsiloxane) as a tubular template material, a series of BC tubes with a length of 100 mm, a thickness of 1 mm and an outer diameter of 4 or 6 mm were biosynthesized with the help of Gluconacetobacter xylinum. Through characterization by SEM (scanning electron microscope), tensile testing and thermal analysis, it is demonstrated that BC tubes are good enough for artificial blood vessel with elaborated nano-fiber architecture, qualified mechanical properties and high thermal stability. In addition, measurement of biocompatibility also shows that BC tubes are greatly adaptable to the in vivo environment. The results indicate that BC tubes have great potential for being utilized as tubular scaffold materials in the field of tissue engineering. - Highlights: • Bacterial cellulose (BC) can be made into tubular shape through PDMS mold. • BC represents a fine nanofiber network. • The mechanical and thermal properties of BC mimic the situation of real vessel. • BC exhibits attractive biocompatible properties as a substitution of vessel

  17. Investigation on artificial blood vessels prepared from bacterial cellulose

    Energy Technology Data Exchange (ETDEWEB)

    Zang, Shanshan; Zhang, Ran; Chen, Hua; Lu, Yudong; Zhou, Jianhai [Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074 (China); Chang, Xiao; Qiu, Guixing; Wu, Zhihong [Department of Orthopaedics, Peking Union Medical College Hospital, Beijing 100730 (China); Yang, Guang, E-mail: yang_sunny@yahoo.com [Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2015-01-01

    BC (bacterial cellulose) exhibits quite distinctive properties than plant cellulose. The outstanding properties make BC a promising material for preparation of artificial blood vessel. By taking advantage of the high oxygen permeability of PDMS (polydimethylsiloxane) as a tubular template material, a series of BC tubes with a length of 100 mm, a thickness of 1 mm and an outer diameter of 4 or 6 mm were biosynthesized with the help of Gluconacetobacter xylinum. Through characterization by SEM (scanning electron microscope), tensile testing and thermal analysis, it is demonstrated that BC tubes are good enough for artificial blood vessel with elaborated nano-fiber architecture, qualified mechanical properties and high thermal stability. In addition, measurement of biocompatibility also shows that BC tubes are greatly adaptable to the in vivo environment. The results indicate that BC tubes have great potential for being utilized as tubular scaffold materials in the field of tissue engineering. - Highlights: • Bacterial cellulose (BC) can be made into tubular shape through PDMS mold. • BC represents a fine nanofiber network. • The mechanical and thermal properties of BC mimic the situation of real vessel. • BC exhibits attractive biocompatible properties as a substitution of vessel.

  18. DLC coating of textile blood vessels using PLD

    Czech Academy of Sciences Publication Activity Database

    Kocourek, Tomáš; Jelínek, Miroslav; Vorlíček, Vladimír; Zemek, Josef; Janča, T.; Žížková, V.; Podlaha, J.; Popov, C.

    2008-01-01

    Roč. 93, č. 3 (2008), s. 627-632. ISSN 0947-8396 R&D Projects: GA MPO FI-IM2/068; GA ČR GA202/06/0216 Institutional research plan: CEZ:AV0Z10100522 Keywords : blood vessels * PLD * DLC * sp2 * sp3 Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.884, year: 2008

  19. A Computational Model Predicting Disruption of Blood Vessel Development

    OpenAIRE

    Kleinstreuer, Nicole; Dix, David; Rountree, Michael; Baker, Nancy; Sipes, Nisha; Reif, David; Spencer, Richard; Knudsen, Thomas

    2013-01-01

    Vascular development is a complex process regulated by dynamic biological networks that vary in topology and state across different tissues and developmental stages. Signals regulating de novo blood vessel formation (vasculogenesis) and remodeling (angiogenesis) come from a variety of biological pathways linked to endothelial cell (EC) behavior, extracellular matrix (ECM) remodeling and the local generation of chemokines and growth factors. Simulating these interactions at a systems level req...

  20. Transmitted Ultrasound Pressure Variation in Micro Blood Vessel Phantoms

    OpenAIRE

    Qin, Shengping; Kruse, Dustin E; Ferrara, Katherine W.

    2008-01-01

    Silica, cellulose, and polymethylmethacrylate tubes with inner diameters of ten to a few hundred microns are commonly used as blood vessel phantoms in in vitro studies of microbubble or nanodroplet behavior during insonation. However, a detailed investigation of the ultrasonic fields within these micro-tubes has not yet been performed. This technical note provides a theoretical analysis of the ultrasonic fields within micro-tubes. Numerical results show that for the same tube material, the in...

  1. Attacks of common migraine or hortons headache may not be accompanied by changes in regional cerebral blood flow

    International Nuclear Information System (INIS)

    Vasospasm and cerebral ischemia, followed by cerebral and extracerebral vasodilation and hyperemia, are generally believed to form the common pathophysiology of the various subtypes of migraine. Mild forms of reactions are thought to result in common migraine (no neurological prodromes or accompaniments), and more severe reactions are thought to induce classical migraine. 8 induced common migraine attacks in 6 patients do not support this unitarian view, as no regional cerebral blood flow changes was found, but suggests a different pathophysiology in common migraine compaired to classical migraine. There are few features in Hortons headache to incriminate the cerebral vessels, and generally patients do not have symptoms attributable to cerebral involvement. In 6 out of 14 patients with known Hortons headache we succesfully induced an attack after alcohol alone or in combination with sublingual nitroglycerine. A slight hyperventilation occurred during the attack, correcting cerebral blood flow for these changes left mean CBF totally unchanged. No regional abnormalities occurred in any of the about 700 regions measured from during each investigation in neither the group with common migraine, nor in the patients with Hortons headache. (Author)

  2. Stem and progenitor cells in biostructure of blood vessel walls

    Directory of Open Access Journals (Sweden)

    Krzysztof Korta

    2013-09-01

    Full Text Available Development of vascular and hematopoietic systems during organogenesis occurs at the same time. During vasculogenesis, a small part of cells does not undergo complete differentiation but stays on this level, “anchored” in tissue structures described as stem cell niches. The presence of blood vessels within tissue stem cell niches is typical and led to identification of niches and ensures that they are functioning. The three-layer biostructure of vessel walls for artery and vein, tunica: intima, media and adventitia, for a long time was defined as a mechanical barrier between vessel light and the local tissue environment. Recent findings from vascular biology studies indicate that vessel walls are dynamic biostructures, which are equipped with stem and progenitor cells, described as vascular wall-resident stem cells/progenitor cells (VW-SC/PC. Distinct zones for vessel wall harbor heterogeneous subpopulations of VW-SC/PC, which are described as “subendothelial or vasculogenic zones”. Recent evidence from in vitro and in vivo studies show that prenatal activity of stem and progenitor cells is not only limited to organogenesis but also exists in postnatal life, where it is responsible for vessel wall homeostasis, remodeling and regeneration. It is believed that VW-SC/PC could be engaged in progression of vascular disorders and development of neointima. We would like to summarize current knowledge about mesenchymal and progenitor stem cell phenotype with special attention to distribution and biological properties of VW-SC/PC in biostructures of intima, media and adventitia niches. It is postulated that in the near future, niches for VW-SC/PC could be a good source of stem and progenitor cells, especially in the context of vessel tissue bioengineering as a new alternative to traditional revascularization therapies.

  3. By Different Cellular Mechanisms, Lymphatic Vessels Sprout by Endothelial Cell Recruitment Whereas Blood Vessels Grow by Vascular Expansion

    Science.gov (United States)

    Parsons-Wingerter, Patricia; McKay, Terri L.; Leontiev, Dmitry; Condrich, Terence K.; DiCorleto, Paul E.

    2005-01-01

    The development of effective vascular therapies requires the understanding of all modes of vessel formation contributing to vasculogenesis, angiogenesis (here termed hemangiogenesis) and lymphangiogenesis. We show that lymphangiogenesis proceeds by blind-ended vessel sprouting via recruitment of isolated endothelial progenitor cells to the tips of growing vessels, whereas hemangiogenesis occurs by non-sprouting vessel expansion from the capillary network, during middevelopment in the quail chorioallantoic membrane (CAM). Blood vessels expanded out of capillaries that displayed transient expression of alpha smooth muscle actin (alphaSMA), accompanied by mural recruitment of migratory progenitor cells expressing SMA. Lymphatics and blood vessels were identified by confocal/fluorescence microscopy of vascular endothelial growth factor (VEGF) receptors VEGFR-1 and VEGFR-2, alphaSMA (expressed on CAM blood vessels but not on lymphatics), homeobox transcription factor Prox-1 (specific to CAM lymphatic endothelium), and the quail hematopoetic/vascular marker, QH-1. Expression of VEGFR-1 was highly restricted to blood vessels (primarily capillaries). VEGFR-2 was expressed intensely in isolated hematopoietic cells, lymphatic vessels and moderately in blood vessels. Prox-1 was absent from endothelial progenitor cells prior to lymphatic recruitment. Although vascular endothelial growth factor-165 (VEGF(sub 165)) is a key regulator of numerous cellular processes in hemangiogenesis and vasculogenesis, the role of VEGF(sub 165) in lymphangiogenesis is less clear. Exogenous VEGF(sub 165) increased blood vessel density without changing endogenous modes of vascular/lymphatic vessel formation or marker expression patterns. However, VEGF(sub 165) did increase the frequency of blood vascular anastomoses and strongly induced the antimaturational dissociation of lymphatics from blood vessels, with frequent formation of homogeneous lymphatic networks.

  4. Understanding and exploiting nanoparticles' intimacy with the blood vessel and blood.

    Science.gov (United States)

    Setyawati, Magdiel Inggrid; Tay, Chor Yong; Docter, Dominic; Stauber, Roland H; Leong, David Tai

    2015-11-21

    While the blood vessel is seldom the target tissue, almost all nanomedicine will interact with blood vessels and blood at some point of time along its life cycle in the human body regardless of their intended destination. Despite its importance, many bionanotechnologists do not feature endothelial cells (ECs), the blood vessel cells, or consider blood effects in their studies. Including blood vessel cells in the study can greatly increase our understanding of the behavior of any given nanomedicine at the tissue of interest or to understand side effects that may occur in vivo. In this review, we will first describe the diversity of EC types found in the human body and their unique behaviors and possibly how these important differences can implicate nanomedicine behavior. Subsequently, we will discuss about the protein corona derived from blood with foci on the physiochemical aspects of nanoparticles (NPs) that dictate the protein corona characteristics. We would also discuss about how NPs characteristics can affect uptake by the endothelium. Subsequently, mechanisms of how NPs could cross the endothelium to access the tissue of interest. Throughout the paper, we will share some novel nanomedicine related ideas and insights that were derived from the understanding of the NPs' interaction with the ECs. This review will inspire more exciting nanotechnologies that had accounted for the complexities of the real human body. PMID:26239875

  5. Unchanged cerebral blood flow and oxidative metabolism after acclimatization to high altitude

    DEFF Research Database (Denmark)

    Møller, Kirsten; Paulson, Olaf B; Hornbein, Thomas F.;

    2002-01-01

    . Global cerebral blood flow at rest and during exercise on a bicycle ergometer was measured by the Kety-Schmidt technique. Cerebral metabolic rates of oxygen, glucose, and lactate were calculated by the Fick principle. Cerebral function was assessed by a computer-based measurement of reaction time...... and cerebral metabolic rates of oxygen and glucose also remained unchanged, whereas cerebral metabolic rates of lactate increased slightly but nonsignificantly at high altitude during exercise compared with high altitude at rest. Reaction time was unchanged. The data indicate that cerebral blood flow...... and oxidative metabolism are unaltered after high-altitude acclimatization from sea level, despite marked changes in breathing and other organ functions....

  6. Role of cerebral blood flow in extreme breath holding

    Directory of Open Access Journals (Sweden)

    Bain Anthony R.

    2016-01-01

    Full Text Available The role of cerebral blood flow (CBF on a maximal breath-hold (BH in ultra-elite divers was examined. Divers (n = 7 performed one control BH, and one BH following oral administration of the non-selective cyclooxygenase inhibitor indomethacin (1.2 mg/kg. Arterial blood gases and CBF were measured prior to (baseline, and at BH termination. Compared to control, indomethacin reduced baseline CBF and cerebral delivery of oxygen (CDO2 by about 26% (p < 0.01. Indomethacin reduced maximal BH time from 339 ± 51 to 319 ± 57 seconds (p = 0.04. In both conditions, the CDO2 remained unchanged from baseline to the termination of apnea. At BH termination, arterial oxygen tension was higher following oral administration of indomethacin compared to control (4.05 ± 0.45 vs. 3.44 ± 0.32 kPa. The absolute increase in CBF from baseline to the termination of apnea was lower with indomethacin (p = 0.01. These findings indicate that the impact of CBF on maximal BH time is likely attributable to its influence on cerebral H+ washout, and therefore central chemoreceptive drive to breathe, rather than to CDO2.

  7. Regional cerebral blood flow after long-term exposure to carbon disulfide

    International Nuclear Information System (INIS)

    Sixteen former rayon viscose workers were investigated four years after the exposure to carbon disulfide was discontinued. Median age was 58 years (range 43-65 years), median exposure time was 17 years (range 10-35 years). Encephalopathy was diagnosed in altogether 14 workers. To further explore pathophysiological mechanisms, cerebrovascular investigations were employed. Doppler ultrasound examination of the precerebral vessels in 15 workers showed a slight stenosis of the left internal carotid artery in one. Regional cerebral blood flow investigation (rCBF) with single photon emission computerized tomography (SPECT) with Xenon-133 gas was performed in 14. There was no significant difference from a control group. Regional side-to-side asymmetries beyond reference limits were demonstrated in eight workers. The abnormalities were modest, but may indicate a tendency toward focal blood flow disturbances in workers with long-term exposure to carbon disulfide. (au)

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

    International Nuclear Information System (INIS)

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

  9. 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).

  10. Effect of anxiety on cortical cerebral blood flow and metabolism

    International Nuclear Information System (INIS)

    The relation between anxiety and cortical activity was compared in two samples of normal volunteers. One group was studied with the noninvasive xenon-133 inhalation technique for measuring cerebral blood flow (CBF) and the other with positron emission tomography (PET) using 18Flurodeoxyglucose (18FDG) for measuring cerebral metabolic rates (CMR) for glucose. The inhalation technique produced less anxiety than the PET procedure, and for low anxiety subjects, there was a linear increase in CBF with anxiety. For higher anxiety subjects, however, there was a linear decrease in CBF with increased anxiety. The PET group manifested a linear decrease in CMR with increased anxiety. The results indicate that anxiety can have systematic effects on cortical activity, and this should be taken into consideration when comparing data from different procedures. They also suggest a physiologic explanation of a fundamental behavioral law that stipulates a curvilinear, inverted-U relationship between anxiety and performance

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

    International Nuclear Information System (INIS)

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

  12. The Utility of Cerebral Blood Flow Assessment in TBI.

    Science.gov (United States)

    Akbik, Omar S; Carlson, Andrew P; Krasberg, Mark; Yonas, Howard

    2016-08-01

    Over the past few decades, intracranial monitoring technologies focused on treating and preempting secondary injury after traumatic brain injury (TBI) have experienced considerable growth. A physiological measure fundamental to the management of these patients is cerebral blood flow (CBF), which may be determined directly or indirectly. Direct measurement has proven difficult previously; however, invasive and non-invasive CBF monitors are now available. This article reviews the history of CBF measurements in TBI as well as the role of CBF in pathologies associated with TBI, such as cerebral autoregulation, hyperemia, and cortical spreading depression. The limitations of various CBF monitors are reviewed in order to better understand their role in TBI management. PMID:27315250

  13. The clinical study of cerebral blood flow imaging in patients with early syphilis

    International Nuclear Information System (INIS)

    Objective: To study the clinical value of cerebral blood flow imaging for evaluation of patients with early syphilis. Methods: Fifty-three patients with early syphilis underwent cerebral blood flow imaging using 99Tcm-ethylenecysteinate dimer(ECD). Regional cerebral blood flow (rCBF) changes were analyzed. Results: The acquired images of 53 patients were graded as 5 types. The rCBF was significantly depressed in 48 of 53 patients mainly in the areas dominated by anterior cerebral artery and middle cerebral artery. Conclusion: Treponema pallidum (TP) could start invading central nervous system at the early stage of infection

  14. EFFECT OF ELECTROACUPUNCTURE OF DUMAI-ACUPOINTS ON CEREBRAL NO AND BLOOD ENDOTHELIN CONTENTS IN RATS WITH ACUTE CEREBRAL ISCHEMIA

    Institute of Scientific and Technical Information of China (English)

    MaYang; XuNenggui; XuGuansun; ZhongPing; WangLianfa; ZhuShunli; ChenQuanzhu

    2000-01-01

    Thirty Wistar rats were randomly and evenly divided into control group, cerebral ischemia group and ischemia + electroacupuncture (EA) group. The bilateral common carotid arteries were occluded to induce acute cerebral ischemia. Nitric oxide (NO) and endothelin (ET)contents in the cerebral tissues and blood were measured under normal condition, immediately after ischemia and following EA. Results showed that after acute cerebral ischemia NO and ET contents in the cerebral tissues increased significantly (P<0.01) while serum ET increased and serum NO lowered obviously (P<0.05). Following EA of Baihui (GV 20) and Dazhui (GV 14), both NO and ET in cerebral tissues and serum turned to normal basically. It showed that EA could protect the cerebral tissues from injury induced by ischemia, NO and ET might participate in the modulation process of EA.

  15. EFFECT OF ELECTROACUPUNCTURE OF DUMAI-ACUPOINTS ON CEREBRAL NO AND BLOOD ENDOTHELIN CONTENTS IN RATS WITH ACUTE CEREBRAL ISCHEMIA

    Institute of Scientific and Technical Information of China (English)

    马杨; 许能贵; 许冠荪; 钟平; 王联发; 朱舜丽; 陈全珠

    2000-01-01

    Thirty Wistar rats were randomly and evenly divided into control group, cerebral ischemia group and ischemia + electroacupuncture (EA) group. The bilateral common carotid arteries were occluded to induce acute cerebral ischemia. Nitric oxide (NO) and endothelin (ET) contents in the cerebral tissues and blood were measured under normal condition, immediately after ischemia and following EA. Results showed that after acute cerebral ischemia NO and ET contents in the cerebral tissues increased significantly (P < 0.01) while serum ET increased and serum NO lowered obviously (P<0.05). Following EA of Baihui (GV 20) and Dazhui (GV 14), both NO and ET in cerebral tissues and serum turned to normal basically. It showed that EA could protect the cerebral tissues from injury induced bv ischemia. NO and ET might oarticioate in the modulation orocess of EA.

  16. Scanning electron microscopy of irradiated recipient blood vessels in head and neck free flaps

    International Nuclear Information System (INIS)

    Irradiated and control recipient blood vessels in a similar patient population were studied with scanning electron microscopy. The vessels that were biopsied were then anastomosed to a free flap. Irradiated arteries display a significantly greater wall thickness and higher incidence of intimal dehiscence compared with control arteries. Fibrin deposition, microthrombi, and endothelium cell dehiscence are present more frequently in irradiated vessels than in control vessels. Details of the preparation and anastomotic technique for irradiated blood vessels are discussed. Microvascular surgery in irradiated human blood vessels carries with it a higher risk of thrombosis due to preexisting vessel wall damage. This risk can be minimized by experience and attention to detail

  17. Hypertension, blood pressure, cognition and cerebral blood flow in the cohort of "Men born 1914"

    OpenAIRE

    Reinprecht, Faina

    2006-01-01

    "Men born 1914" is a population based cohort study of the epidemiology of cardiovascular disease. Five hundred men, born 1914, were examined at the age of 68 and 185 of them were re-examined at 81 years of age. Examination included a medical and a psychological investigation, ultrasonographic measurement of carotid arteries, 24-hour ambulatory blood pressure monitoring, regional cerebral blood flow, and cardiovascular risk factors. It is well known that hypertension plays a major et...

  18. Relations of blood pressure and head injury to regional cerebral blood flow.

    Science.gov (United States)

    Kisser, Jason E; Allen, Allyssa J; Katzel, Leslie I; Wendell, Carrington R; Siegel, Eliot L; Lefkowitz, David; Waldstein, Shari R

    2016-06-15

    Hypertension confers increased risk for cognitive decline, dementia, and cerebrovascular disease. These associations have been attributed, in part, to cerebral hypoperfusion. Here we posit that relations of higher blood pressure to lower levels of cerebral perfusion may be potentiated by a prior head injury. Participants were 87 community-dwelling older adults - 69% men, 90% white, mean age=66.9years, 27.6% with a history of mild traumatic brain injury (mTBI) defined as a loss of consciousness ≤30min resulting from an injury to the head, and free of major medical (other than hypertension), neurological or psychiatric comorbidities. All engaged in clinical assessment of systolic and diastolic blood pressure (SBP, DBP) and single photon emission computed tomography (SPECT). Computerized coding of the SPECT images yielded relative ratios of blood flow in left and right cortical and select subcortical regions. Cerebellum served as the denominator. Sex-stratified multiple regression analyses, adjusted for age, education, race, alcohol consumption, smoking status, and depressive symptomatology, revealed significant interactions of blood pressure and head injury to cerebral blood flow in men only. Specifically, among men with a history of head injury, higher systolic blood pressure was associated with lower levels of perfusion in the left orbital (β=-3.21, p=0.024) and left dorsolateral (β=-2.61, p=0.042) prefrontal cortex, and left temporal cortex (β=-3.36, p=0.014); higher diastolic blood pressure was marginally associated with lower levels of perfusion in the left dorsolateral prefrontal cortex (β=-2.79, p=0.051). Results indicate that men with a history of head injury may be particularly vulnerable to the impact of higher blood pressure on cerebral perfusion in left anterior cortical regions, thus potentially enhancing risk for adverse brain and neurocognitive outcomes. PMID:27206865

  19. Effect of coil embolization on blood flow through a saccular cerebral aneurysm

    Indian Academy of Sciences (India)

    Vishal Agrawal; Chandan Paul; M K Das; K Muralidhar

    2015-05-01

    Coil embolization is a mildly invasive endovascular method for treatment of a cerebral aneurysm. The presence of a coil reduces fluid loading of the blood vessel and delays further deformation of the walls. Its effectiveness depends on the coil porosity and permeability apart from the nature of flow pulsations and its geometry. In the present work, a three dimensional numerical study of pulsatile flow of blood through an artery with saccular cerebral aneurysm is reported. The flow is unsteady but is taken to be laminar and incompressible. The coil is treated as homogeneous and isotropic porous medium. A comparative study has been carried out on aneurysms with and without a coil insert considering blood as a non-Newtonian fluid. The simulation is carried out for Reynolds numbers $Re$ = 500 and 1500. Results show that the velocity magnitude within the coil embolized aneurysm becomes negligible after coil insertion. The wall shear stress within the aneurysm decreases to a great extent for both Reynolds numbers. Pressure levels remain relatively unchanged. Overall, reduced wall loading with a coil stabilizes the growth of the aneurysm and thus provides an advantage.

  20. Modulation of cerebral blood flow with transcutaneous electrical neurostimulation (TENS) in patients with cerebral vasospasm after subarachnoid hemorrhage

    NARCIS (Netherlands)

    ter Laan, Mark; van Dijk, J.M.C.; Stewart, Roy; Staal, Michiel J; Elting, Jan-Willem J

    2014-01-01

    ObjectivesTranscutaneous electrical neurostimulation (TENS) and spinal cord stimulation have been shown to increase peripheral and cerebral blood flow. We postulate that certain pathological conditions attenuate cerebral autoregulation, which may result in a relative increase of the importance of ne

  1. Changes in the cerebral blood flow in newborn rats assessed by LSCI and DOCT before and after the hemorrhagic stroke

    Science.gov (United States)

    Semyachkina-Glushkovskaya, O. V.; Lychagov, V. V.; Abdurashitov, A. S.; Sindeeva, O. V.; Sindeev, S. S.; Zinchenko, E. M.; Kajbeleva, E. I.; Pavlov, A. N.; Kassim, M.; Tuchin, V. V.

    2015-03-01

    The incidence of perinatal hemorrhagic stroke (HS) is very similar to that in the elderly and produces a significant morbidity and long-term neurologic and cognitive deficits. There is strong evidence that cerebral blood flow (CBF) abnormalities make considerable contribution to HS development. However, the mechanisms responsible for pathological changes in CBF in infants with HS are not established. Therefore, quantitative assessment of CBF may significantly advance the understanding of the nature of neonatal stroke. The aim of this investigation was to determine the particularities of alterations in macro- microcirculation in the brain of newborn rats in the different stages of stress-related development of HS using three-dimensional Doppler optical coherence tomography (DOCT) and laser speckle contrast imaging (LSCI).Our results show that cerebral veins are more sensitive to harmful effect of stress compared with microcirculatory vessels. Stress-induced progressive dilation of cerebral veins with the fall of blood flow velocity precedes HS while pathological changes in microcirculatory vessels are accompanied by development of HS. The further detailed study of cerebral venous and microcirculatory circulation would be a significant advance in development of prognostic criteria for a HS risk during the first days after birthday.

  2. Vitamin D status and vascular dementia due to cerebral small vessel disease in the elderly Asian Indian population.

    Science.gov (United States)

    Prabhakar, Puttachandra; Chandra, Sadanandavalli Retnaswami; Supriya, Manjunath; Issac, Thomas Gregor; Prasad, Chandrajit; Christopher, Rita

    2015-12-15

    Vitamin D plays vital roles in human health and recent studies have shown its beneficial effect on brain functioning. The present study was designed to evaluate the association of vitamin D with vascular dementia (VaD) due to cerebral small vessel disease (SVD) in Asian Indian population. 140 VaD patients aged ≥ 60 years with neuroimaging evidence of SVD, and 132 age and gender-matched controls, were investigated. Vitamin D status was estimated by measuring serum 25-hydroxy vitamin D. Logistic regression model revealed that deficient levels of vitamin D (vitamin D deficiency and insufficiency (12-20 ng/ml), the odds were increased to 31.6-fold and 14.4-fold, respectively. However, in hypertensives with vitamin D sufficiency (>20 ng/ml), the odds of VaD were increased by 3.8-fold only. Pearson correlation showed that serum vitamin D was inversely associated with systolic and diastolic blood pressure (r=-0.401 and -0.411, pvitamin D-deficient subjects. Since the combined presence of hypertension and vitamin D deficiency increases the probability of developing VaD, screening for vitamin D status in addition to regular monitoring of blood pressure, could reduce the risk of VaD associated with cerebral SVD in the elderly Asian Indian subjects. PMID:26671097

  3. Cerebral blood flow is reduced in patients with sepsis syndrome

    International Nuclear Information System (INIS)

    The relationship between sepsis-induced CNS dysfunction and changes in brain blood flow remains unknown, and animal studies examining the influence of sepsis on cerebral blood flow (CBF) do not satisfactorily address that relationship. We measured CBF and cerebrovascular reactivity to CO2 in nine patients with sepsis syndrome using the 133Xe clearance technique. Mean CBF was 29.6 +/- 15.8 (SD) ml/100 g.min, significantly lower than the normal age-matched value in this laboratory of 44.9 +/- 6.2 ml/100 g.min (p less than .02). This depression did not correlate with changes in mean arterial pressure. Despite the reduction in CBF, the specific reactivity of the cerebral vasculature to changes in CO2 was normal, 1.3 +/- 0.9 ml/100 g.min/mm Hg. Brain blood flow is reduced in septic humans; the contribution of this reduction to the metabolic and functional changes observed in sepsis requires further study

  4. Narcolepsy: regional cerebral blood flow during sleep and wakefulness

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, F.; Meyer, J.S.; Karacan, I.; Yamaguchi, F.; Yamamoto, M.

    1979-01-01

    Serial measurements of regional cerebral blood flow were made by the 135Xe inhalation method during the early stages of sleep and wakefulness in eight normal volunteers and 12 patients with narcolepsy. Electroencephalogram, electro-oculogram, and submental electromyogram were recorded simultaneously. In normals, mean hemispheric gray matter blood flow (Fg) during stages I and II sleep was significantly less than waking values. Maximum regional blood flow decreases during sleep occurred in the brainstem-cerebellar, right inferior temporal, and bilateral frontal regions. In patients with narcolepsy, mean hemispheric Fg while awake was 80.5 +- 13 ml per 100 gm brain per minute. During REM sleep, mean hemispheric Fg increased concurrently with large increases in brainstem-cerebellar region flow. During stages I and II sleep without REM, there were significant increases in mean hemispheric Fg and brainstem-cerebellar Fg, just the opposite of changes in normals. In narcolepsy, there appears to be a reversal of normal cerebral deactivation patterns, particularly involving the brainstem, during stages I and II sleep.

  5. Over-expression of Slit2 induces vessel formation and changes blood vessel permeability in mouse brain

    Institute of Scientific and Technical Information of China (English)

    Hai-xiong HAN; Jian-guo GENG

    2011-01-01

    Aim:To investigate the effect of the axon guidance cue Slit2 on the density of blood vessels and permeability of the blood-brain barrier in mouse brain.Methods:hSlit2 transgenic mouse line was constructed,and the phenotypes of the mice were compared with wild-type mice in respect to the lateral ventricle (LV),ventricle pressure,and the choroids plexus.An in vivo Miles permeability assay and an amyloid-β permeability assay were used to assess the permeability of brain blood vessels.Brain vessel casting and intracerebral hemorrhage models were built to investigate vessel density in the transgenic mice.An in vitro permeability assay was used to test whether Slit2 could change the permeability and tight junctions of blood vessel endothelial cells.Results:Hydrocephalus occurred in some transgenic mice,and a significantly larger lateral ventricle area and significantly higher ventricle pressure were observed in the transgenic mice.The transgenic mice displayed changed construction of the choroids plexus,which had more micro vessels,dilated vessels,gaps between epithelial cells and endothelial cells than wild-type mice.Slit2 significantly increased brain vessel density and the permeability of brain vessels to large molecules.These blood vessels were more sensitive to cues that induce brain hemorrhage.At the cellular level,Slit2 disturbed the integrity of tight junctions in blood vessel endothelial cells and improved the permeability of the endothelial cell layer.Thus,it promoted the entry of amyloid-β peptides from the serum into the central nervous system,where they bound to neurons.Conclusion:Slit2 increases vessel density and permeability in the brains of transgenic mice.Thus,Slit2 induces numerous changes in brain vessels and the barrier system.

  6. Modeling Of Blood Vessel Constriction In 2-D Case Using Molecular Dynamics Method

    CERN Document Server

    Rendi, Mohamad; Viridi, Sparisoma

    2013-01-01

    Blood vessel constriction is simulated with particle-based method using a molecular dynamics authoring software known as Molecular Workbench (WM). Blood flow and vessel wall, the only components considered in constructing a blood vessel, are all represented in particle form with interaction potentials: Lennard-Jones potential, push-pull spring potential, and bending spring potential. Influence of medium or blood plasma is accommodated in plasma viscosity through Stokes drag force. It has been observed that pressure p is increased as constriction c is increased. Leakage of blood vessel starts at 80 % constriction, which shows existence of maximum pressure that can be overcome by vessel wall.

  7. Regional cerebral blood flow during comprehension and speech (in cerebrally healthy subjects)

    International Nuclear Information System (INIS)

    Regional cerebral blood flow (rCBF) was measured by the xenon-133 inhalation method in 10 cerebrally healthy subjects at rest and during linguistic activation tests. These consisted of a comprehension test (binaural listening to a narrative text) and a speech test (making sentences from a list of words presented orally at 30-s intervals). The comprehension task induced a moderate increase in the mean right CBF and in both inferior parietal areas, whereas the speech test resulted in a diffuse increase in the mean CBF of both hemispheres, predominating regionally in both inferior parietal, left operculary, and right upper motor and premotor areas. It is proposed that the activation pattern induced by linguistic stimulation depends on not only specific factors, such as syntactic and semantic aspects of language, but also the contents of the material proposed and the attention required by the test situation

  8. Cerebrovascular dysfunction and microcirculation rarefaction precede white matter lesions in a mouse genetic model of cerebral ischemic small vessel disease

    OpenAIRE

    Joutel, A.; Monet-Lepretre, M.; Gosele, C.; Baron-Menguy, C.; Hammes, A.; Schmidt, S.; Lemaire-Carrette, B.; Domenga, V.; Schedl, A; Lacombe, P.; Huebner, N.

    2010-01-01

    Cerebral ischemic small vessel disease (SVD) is the leading cause of vascular dementia and a major contributor to stroke in humans. Dominant mutations in NOTCH3 cause cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), a genetic archetype of cerebral ischemic SVD. Progress toward understanding the pathogenesis of this disease and developing effective therapies has been hampered by the lack of a good animal model. Here, we report the developmen...

  9. Methylphenidate decreases regional cerebral blood flow in normal human subjects

    Energy Technology Data Exchange (ETDEWEB)

    Wang, G.J.; Volkow, N.D. (Brookhaven National Lab., Upton, NY (United States) SUNY, Stony Brook, NY (United States)); Fowler, J.S.; Ferrieri, R.; Schlyer, D.J.; Alexoff, D.; Warner, D.; Wolf, A.P.; Pappas, N.; King, P.; Wong, C. (Brookhaven National Lab., Upton, NY (United States)); Hitzemann, R.J. (SUNY, Stony Brook, NY (United States)); Lieberman, J. (Hillside Hospital, Glen Oaks, NY (United States))

    1994-01-01

    To assess the effects of methylphenidate (MP) on cerebral blood flow (CBF), 5 healthy males were studied using [sup 15]O-water and positron emission tomography before and after MP (0.5mg/kg iv). MP significantly decreased whole brain CBF at 5-10 minutes (25[+-]11%) and at 30 minutes (20[+-]10%) after its administration. Decrements in CBF were homogeneous throughout the brain (regional decrements 23-30%) and probably reflect the vasoactive properties of MP. The vasoactive properties of MP should be considered when prescribing this drug chronically and/or when giving it to subjects with cerebrovascular compromise.

  10. Detection of white matter lesions in cerebral small vessel disease

    Science.gov (United States)

    Riad, Medhat M.; Platel, Bram; de Leeuw, Frank-Erik; Karssemeijer, Nico

    2013-02-01

    White matter lesions (WML) are diffuse white matter abnormalities commonly found in older subjects and are important indicators of stroke, multiple sclerosis, dementia and other disorders. We present an automated WML detection method and evaluate it on a dataset of small vessel disease (SVD) patients. In early SVD, small WMLs are expected to be of importance for the prediction of disease progression. Commonly used WML segmentation methods tend to ignore small WMLs and are mostly validated on the basis of total lesion load or a Dice coefficient for all detected WMLs. Therefore, in this paper, we present a method that is designed to detect individual lesions, large or small, and we validate the detection performance of our system with FROC (free-response ROC) analysis. For the automated detection, we use supervised classification making use of multimodal voxel based features from different magnetic resonance imaging (MRI) sequences, including intensities, tissue probabilities, voxel locations and distances, neighborhood textures and others. After preprocessing, including co-registration, brain extraction, bias correction, intensity normalization, and nonlinear registration, ventricle segmentation is performed and features are calculated for each brain voxel. A gentle-boost classifier is trained using these features from 50 manually annotated subjects to give each voxel a probability of being a lesion voxel. We perform ROC analysis to illustrate the benefits of using additional features to the commonly used voxel intensities; significantly increasing the area under the curve (Az) from 0.81 to 0.96 (p<0.05). We perform the FROC analysis by testing our classifier on 50 previously unseen subjects and compare the results with manual annotations performed by two experts. Using the first annotator results as our reference, the second annotator performs at a sensitivity of 0.90 with an average of 41 false positives per subject while our automated method reached the same

  11. Regional cerebral blood flow before and after vascular surgery in patients with transient ischemic attacks with 133-xenon inhalation tomography

    DEFF Research Database (Denmark)

    Vorstrup, S; Hemmingsen, Ralf; Lindewald, H; Lassen, Niels Alexander

    Cerebral blood flow CBF was studied in 14 patients with transient ischemic attacks TIA and arteriosclerotic neck vessel disease. CBF was measured by a rapidly rotating single photon emission computerized tomograph using Xenon-133 inhalation. This method yields images of 3 brain slices depicting CBF...... with no abnormality on the CT-scan. The abnormal blood flow pattern was found to be unchanged after clinically successful reconstructive vascular surgery. This suggests the presence of irreversible ischemic tissue damage without gross emollition (incomplete infarction). It is concluded, that TIAs are...

  12. Regional cerebral blood flow in patients with transient ischemic attacks studied by Xenon-133 inhalation and emission tomography

    DEFF Research Database (Denmark)

    Vorstrup, S; Hemmingsen, R; Henriksen, L; Lindewald, H; Engell, Hans; Lassen, N A

    1983-01-01

    Cerebral blood flow CBF was studied in 14 patients with transient ischemic attacks TIA and arteriosclerotic neck vessel disease. CBF was measured by a rapidly rotating single photon emission computerized tomograph using Xenon-133 inhalation. This method yields images of 3 brain slices depicting CBF...... with no abnormality on the CT-scan. The abnormal blood flow pattern was found to be unchanged after clinically successful reconstructive vascular surgery. This suggests the presence of irreversible ischemic tissue damage without gross emollition (incomplete infarction). It is concluded, that TIAs are...

  13. In vivo cerebral blood flow autoregulation studies using rheoencephalography

    Science.gov (United States)

    Bodo, M.; Pearce, F.; Garcia, A.; Van Albert, S.; Settle, T.; Szebeni, J.; Baranyi, L.; Hartings, J.; Armonda, R.

    2010-04-01

    Acute management of patients with traumatic brain/blast injury is a challenge. To minimize secondary injury and improve outcome, it is critical to detect neurological deterioration early, when it is potentially reversible. One potential monitoring method is cerebral electrical impedance (rheoencephalography-REG) because of its non-invasiveness and good time resolution. Reported here are the results of cerebral blood flow (CBF) manipulations comparing electroencephalogram (EEG) with REG (both intra-cerebral) and measuring with surface and skull REG electrodes. Our hypothesis was that REG would reflect spreading depression and CBF autoregulation. Animal experiments were performed using one rat (four trials with intracerebral electrodes), monkeys (n=8, with surface electrodes) and pigs (n = 24 pigs with skull electrodes; 57 trials, 19 types of liposomes). Challenges included intracranial pressure (ICP) elevation, liposome infusion, and hemorrhage. Data were stored on a PC and evaluated off line. CBF autoregulation was evaluated both by visual inspection and by a Matlab script. These studies confirmed that REG reflects CBF autoregulation and that REG is useful for detecting spreading depression (SD), vasospasm and the lower limit of CBF autoregulation. These findings have clinical relevance for use in noninvasive neuro-monitoring in the neurosurgery intensive care and during transportation of patients with brain injury.

  14. Decreased cerebral blood flow in renal transplant recipients

    International Nuclear Information System (INIS)

    We performed single-photon emission computed tomography (SPECT) to investigate the influence of renal transplantation on cerebral blood flow (CBF). Fifteen renal transplant recipients and twelve normal subjects underwent cerebral SPECT with N-isopropyl-p-[123I] iodoamphetamine (123I-IMP). All transplant recipients received prednisolone and cyclosporine (CyA). Regional CBF (rCBF) was measured by defining regions of interest in the cerebral cortex, deep white matter, striatum, thalamus, and cerebellum. In transplant recipients, correlations to the mean overall cortical CBF were assessed using the interval from transplantation to measurement of SPECT, as well as the serum creatinine concentration. Moreover, to investigate the influence of CyA on CBF, the correlation between mean overall cortical CBF and CyA trough concentrations was assessed. In all regions, CBF in renal transplant recipients was significantly lower than in normal subjects. No significant correlation was seen between serum creatinine, interval from transplantation, or CyA trough concentrations and mean overall cortical CBF. Renal transplant recipients demonstrated a decrease in CBF, that can have an associated secondary pathology. Therefore, renal transplant recipients may benefit from post-operative MRI or CT. (author)

  15. Angiogenesis and blood vessel stability in inflammatory arthritis.

    LENUS (Irish Health Repository)

    Kennedy, Aisling

    2012-02-01

    OBJECTIVE: To assess blood vessel stability in inflammatory synovial tissue (ST) and to examine neural cell adhesion molecule (NCAM), oxidative DNA damage, and hypoxia in vivo. METHODS: Macroscopic vascularity and ST oxygen levels were determined in vivo in patients with inflammatory arthritis who were undergoing arthroscopy. Vessel maturity\\/stability was quantified in matched ST samples by dual immunofluorescence staining for factor VIII (FVIII)\\/alpha-smooth muscle actin (alpha-SMA). NCAM and 8-oxo-7,8-dihydro-2\\'-deoxyguanosine (8-oxodG) were examined by immunohistochemistry. Angiogenesis was assessed in vitro, using human dermal endothelial cells (HDECs) in a Matrigel tube formation assay. RESULTS: A significant number of immature vessels (showing no pericyte recruitment) was observed in tissue from patients with inflammatory arthritis (P < 0.001), in contrast to osteoarthritic and normal tissue, which showed complete recruitment of pericytes. Low in vivo PO(2) levels in the inflamed joint (median [range] 22.8 [3.2-54.1] mm Hg) were inversely related to increased macroscopic vascularity (P < 0.04) and increased microscopic expression of FVIII and alpha-SMA (P < 0.04 and P < 0.03, respectively). A significant proportion of vessels showed focal expression of NCAM and strong nuclear 8-oxodG expression, implicating a loss of EC-pericyte contact and increased DNA damage, levels of which were inversely associated with low in vivo PO(2) (P = 0.04 for each comparison). Circulating cells were completely negative for 8-oxodG. Exposure of HDEC to 3% O(2) (reflecting mean ST in vivo measurements) significantly increased EC tube formation (P < 0.05). CONCLUSION: Our findings indicate the presence of unstable vessels in inflamed joints associated with hypoxia, incomplete EC-pericyte interactions, and increased DNA damage. These changes may further contribute to persistent hypoxia in the inflamed joint to further drive this unstable microenvironment.

  16. Ultrastructural analysis of small blood vessels in skin biopsies in CADASIL

    Directory of Open Access Journals (Sweden)

    Lačković Vesna

    2008-01-01

    Full Text Available Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL is an inherited small- and medium-artery disease of the brain caused by mutation of the Notch3 gene. Very often, this disease is misdiagnosed. We examined skin biopsies in two members of the first discovered Serbian family affected by CADASIL. Electron microscopy showed that skin blood vessels of both patients contain numerous deposits of granular osmiophilic material (GOM around vascular smooth muscle cells (VSMCs. We observed degeneration of VSMCs, reorganization of their cytoskeleton and dense bodies, disruption of myoendothelial contacts, and apoptosis. Our results suggest that the presence of GOM in small skin arteries represents a specific marker in diagnosis of CADASIL.

  17. Plasma membrane electron transport in frog blood vessels

    Indian Academy of Sciences (India)

    Rashmi P Rao; K Nalini; J Prakasa Rao

    2009-12-01

    In an attempt to see if frog blood vessels possess a plasma membrane electron transport system, the postcaval vein and aorta isolated from Rana tigrina were tested for their ability to reduce ferricyanide, methylene blue, and 2,6-dichloroindophenol. While the dyes remained unchanged, ferricyanide was reduced to ferrocyanide. This reduction was resistant to inhibition by cyanide and azide. Heptane extraction or formalin fixation of the tissues markedly reduced the capability to reduce ferricyanide. Denuded aortas retained only 30% of the activity of intact tissue. Our results indicate that the amphibian postcaval vein and aorta exhibit plasma membrane electron transport

  18. Cerebral blood flow and metabolism in multi-infarct dementia

    International Nuclear Information System (INIS)

    Cerebral blood flow and oxygen metabolism were studied in three aged normal volunteers and 10 patients with multi-infarct dementia (MID) by Positron Emission Tomography using O-15. The diagnosis of MID was done according to the Loeb's modified ischemic score and X-ray CT findings. The MID patients, whose X-ray CT showed localized low density areas in the subcortical white matter and basal ganglia and thalamus, were studied. No occulusion was observed at anterior cerebral artery and/or middle cerebral artery on cerebral angiography. All cases of MID were mild dementias. Regional CBF, rOEF and rCMRO2 were measured by the steady state technique described by Terry Jones et al. The values of rCBF in MID patients were significantly low compared with those of aged normal subjects in frontal, temporal, occipital, parietal cortices and thalamus. The values of CMRO2 in MID were significantly low in frontal, temporal, occipital cortices and thalamus compared with normal subjects'. The OEF was 0.46 in aged normal subjects, and 0.52 in MID patients. The MID patients in the early stage of dementia showed the increased oxygen extraction fraction, and this fact suggests that ischemia is a significant pathogenic mechanism in the production and progression of multi-infarct dementia. The decrease of CBF and CMRO2 in MID compared from normal subjects' were most remarkable in frontal cortex. The impairment of mental functions in MID should be caused by the decreased neuronal activities in frontal association cortex. (author)

  19. [Blood viscosity and blood factors in non-embolic cerebral infarction].

    Science.gov (United States)

    Fong, C S; Chia, L G

    1990-11-01

    We compared blood viscosity at a high and a low shear rate, hematocrit, as well as levels of fibrinogen, cholesterol, triglyceride and high density lipoprotein-cholesterol between 42 patients with nonembolic cerebral infarction and 39 normal subjects. Blood viscosity, levels of fibrinogen, cholesterol and triglyceride were significantly higher, and high density lipoprotein-cholesterol levels were significantly lower, in patients than in normal persons. Blood viscosity had a positive correlation with hematocrit and fibrinogen, and a negative correlation with high density lipoprotein-cholesterol, but no correlation with cholesterol and triglyceride. PMID:1982124

  20. DSA Image Blood Vessel Skeleton Extraction Based on Anti-concentration Diffusion and Level Set Method

    Science.gov (United States)

    Xu, Jing; Wu, Jian; Feng, Daming; Cui, Zhiming

    Serious types of vascular diseases such as carotid stenosis, aneurysm and vascular malformation may lead to brain stroke, which are the third leading cause of death and the number one cause of disability. In the clinical practice of diagnosis and treatment of cerebral vascular diseases, how to do effective detection and description of the vascular structure of two-dimensional angiography sequence image that is blood vessel skeleton extraction has been a difficult study for a long time. This paper mainly discussed two-dimensional image of blood vessel skeleton extraction based on the level set method, first do the preprocessing to the DSA image, namely uses anti-concentration diffusion model for the effective enhancement and uses improved Otsu local threshold segmentation technology based on regional division for the image binarization, then vascular skeleton extraction based on GMM (Group marching method) with fast sweeping theory was actualized. Experiments show that our approach not only improved the time complexity, but also make a good extraction results.

  1. Determinants of resting cerebral blood flow in sickle cell disease.

    Science.gov (United States)

    Bush, Adam M; Borzage, Matthew T; Choi, Soyoung; Václavů, Lena; Tamrazi, Benita; Nederveen, Aart J; Coates, Thomas D; Wood, John C

    2016-09-01

    Stroke is common in children with sickle cell disease and results from an imbalance in oxygen supply and demand. Cerebral blood flow (CBF) is increased in patients with sickle cell disease to compensate for their anemia, but adequacy of their oxygen delivery has not been systematically demonstrated. This study examined the physiological determinants of CBF in 37 patients with sickle cell disease, 38 ethnicity matched control subjects and 16 patients with anemia of non-sickle origin. Cerebral blood flow was measured using phase contrast MRI of the carotid and vertebral arteries. CBF increased inversely to oxygen content (r(2)  = 0.69, P Brain oxygen delivery, the product of CBF and oxygen content, was normal in all groups. Brain composition, specifically the relative amounts of grey and white matter, was the next strongest CBF predictor, presumably by influencing cerebral metabolic rate. Grey matter/white matter ratio and CBF declined monotonically until the age of 25 in all subjects, consistent with known maturational changes in brain composition. Further CBF reductions were observed with age in subjects older than 35 years of age, likely reflecting microvascular aging. On multivariate regression, CBF was independent of disease state, hemoglobin S, hemoglobin F, reticulocyte count and cell free hemoglobin, suggesting that it is regulated similarly in patients and control subjects. In conclusion, sickle cell disease patients had sufficient oxygen delivery at rest, but accomplish this only by marked increases in their resting CBF, potentially limiting their ability to further augment flow in response to stress. Am. J. Hematol. 91:912-917, 2016. © 2016 Wiley Periodicals, Inc. PMID:27263497

  2. Relationship between cardiac function and resting cerebral blood flow

    DEFF Research Database (Denmark)

    Henriksen, Otto M; Jensen, Lars T; Krabbe, Katja;

    2014-01-01

    and cardiac output were measured in 31 healthy subjects 50-75 years old using magnetic resonance imaging techniques. Mean values of CBF, cardiac output and cardiac index were 43.6 ml per 100 g min(-1), 5.5 l min(-1) and 2.7 l min(-1) m(-2), respectively, in males, and 53.4 ml per 100 g min(-1), 4.3 l......Although both impaired cardiac function and reduced cerebral blood flow are associated with ageing, current knowledge of the influence of cardiac function on resting cerebral blood flow (CBF) is limited. The aim of this study was to investigate the potential effects of cardiac function on CBF. CBF...... min(-1) and 2.4 l min(-1) m(-2), respectively, in females. No effects of cardiac output or cardiac index on CBF or structural signs of brain ageing were observed. However, fractional brain flow defined as the ratio of total brain flow to cardiac output was inversely correlated with cardiac index (r(2...

  3. Blood biomarkers in the early stage of cerebral ischemia.

    Science.gov (United States)

    Maestrini, I; Ducroquet, A; Moulin, S; Leys, D; Cordonnier, C; Bordet, R

    2016-03-01

    In ischemic stroke patients, blood-based biomarkers may be applied for the diagnosis of ischemic origin and subtype, prediction of outcomes and targeted treatment in selected patients. Knowledge of the pathophysiology of cerebral ischemia has led to the evaluation of proteins, neurotransmitters, nucleic acids and lipids as potential biomarkers. The present report focuses on the role of blood-based biomarkers in the early stage of ischemic stroke-within 72h of its onset-as gleaned from studies published in English in such patients. Despite growing interest in their potential role in clinical practice, the application of biomarkers for the management of cerebral ischemia is not currently recommended by guidelines. However, there are some promising clinical biomarkers, as well as the N-methyl-d-aspartate (NMDA) peptide and NMDA-receptor (R) autoantibodies that appear to identify the ischemic nature of stroke, and the glial fibrillary acidic protein (GFAP) that might be able to discriminate between acute ischemic and hemorrhagic strokes. Moreover, genomics and proteomics allow the characterization of differences in gene expression, and protein and metabolite production, in ischemic stroke patients compared with controls and, thus, may help to identify novel markers with sufficient sensitivity and specificity. Additional studies to validate promising biomarkers and to identify novel biomarkers are needed. PMID:26988891

  4. Alterations of Regional Cerebral Blood Flow in Major Depressive Disorder

    International Nuclear Information System (INIS)

    The authors analyzed how the regional cerebral blood flow (rCBF) findings of patients with major depression differ from the normal control, and our results were compared to previous reports. Twelve patients fulfilling DSM-IV criteria for major depression who were off all psychotropic medications for > 4 weeks (male: 7, female: 5, age range: 19∼52 years, average age: 29.3±9.9 years) and 14 normal volunteers (male: 8, female: 6, age range: 19∼53 years, average age: 31.4±9.2 years) were recruited. Images of brain perfusion SPECT were obtained using Tc-99m ECD and patterns of the rCBF were compared between patients with major depression and the healthy control subjects. The patients with major depression showed increase of the r-CBF in right lingual gyrus, right fusiform gyrus, left lingual gyrus, left precuneus, and left superior temporal gyrus, and showed decrease of r-CBF in right pons, left medial frontal gyrus, cingulate gyrus of left limbic lobe, cingulate gyrus of right frontal lobe, and cingulate gyrus of right limbic lobe compared to the normal control. The Tc-99m ECD brain perfusion SPECT findings in our study did not differ from the previously reported regional cerebral blood flow pattern of patients with major depression. Especially, decreased rCBF pattern typical to major depression patients in the right pons, left medial frontal gyrus, and cingulate regions was clearly demonstrated

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

    International Nuclear Information System (INIS)

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

  6. Photoperiodic Regulation of Cerebral Blood Flow in White-Footed Mice (Peromyscus leucopus).

    Science.gov (United States)

    Borniger, Jeremy C; Teplitsky, Seth; Gnyawali, Surya; Nelson, Randy J; Rink, Cameron

    2016-01-01

    Individuals living outside the tropics need to adjust their behavioral and physiological repertoires throughout the year to adapt to the changing seasons. White-footed mice (Peromyscus leucopus) reduce hippocampal volumes, hippocampal-dependent memory function, long-term potentiation, and alter neurogenesis in response to short (winter-like) day lengths (photoperiods). During winter, these mice putatively shunt energy away from the brain to maximize peripheral thermogenesis, immune function, and survival. We hypothesized that these changes in brain function are accompanied by alterations in brain vasculature. We maintained white-footed mice in short (8 h light/16 h dark) or long (16 h light/8 h dark) photoperiods for 8-9 weeks. Mice were then perfused with fluorescein isothiocyanate (FITC)-conjugated tomato (Lycopersicon esculentum) lectin to visualize the perfused cerebrovasculature. Short-day mice reduced hippocampal and cortical capillary density (FITC(+) area); vessels isolated from short day-exposed mice expressed higher mRNA levels of the gelatinase matrix metalloproteinase 2 (MMP2). Additionally, short-day mice reduced cerebral blood flow ∼15% compared with their long-day counterparts, as assessed by laser speckle flowmetry. Immunohistochemistry revealed higher levels of MMP2 in the hippocampus of mice maintained in short days compared with long days, potentially contributing to the observed vascular remodeling. These data demonstrate that a discrete environmental signal (i.e., day length) can substantially alter cerebral blood flow in adult mammals. PMID:27570829

  7. PET/CT imaging of atherosclerotic blood vessel alterations

    International Nuclear Information System (INIS)

    Atherosclerosis is a chronic inflammatory disease of middle sized and large vessels with sequelae comprising the most frequent causes of death in the Western world. Modern imaging modalities are being introduced for the study of atherosclerosis with emphasis on the detection of vulnerable plaques. The hybrid imaging method PET/CT presents advantages for the localization of vulnerable plaques based on the uptake of various molecular imaging agents indicative of inflammatory processes. Using semiquantitative image analysis fluorodeoxyglucose (FDG) uptake in large peripheral vessels has been identified in a series of 21 patients, who were scanned first with the previous generation of PET/CT scanner and subsequently with a new generation apparatus, after a mean interval of 6.5 months. The mean ratio of FDG uptake in the walls of eight large vessels to the blood-pool activity (TBR) was nearly identical in the two PET/CT sessions (TBR1 1.26 versus TBR2 1.28; p=n.s.), indicating independence of the TBR endpoint from the particular instrumentation. (orig.)

  8. Cerebral small-resistance artery structure and cerebral blood flow in normotensive subjects and hypertensive patients

    Energy Technology Data Exchange (ETDEWEB)

    De Ciuceis, Carolina; Porteri, Enzo; Rizzoni, Damiano; Boari, Gianluca E.M.; Rosei, Enrico Agabiti [University of Brescia, Clinica Medica, Department of Clinical and Experimental Sciences, Brescia (Italy); Cornali, Claudio; Mardighian, Dikran; Fontanella, Marco M. [University of Brescia, Section of Neurosurgery, Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, Brescia (Italy); Pinardi, Chiara [Spedali Civili, Medical Physics Unit, Brescia (Italy); University of Brescia, Section of Neuroradiology, Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, Brescia (Italy); Rodella, Luigi F.; Rezzani, Rita [University of Brescia, Section of Anatomy, Department of Clinical and Experimental Sciences, Brescia (Italy); Gasparotti, Roberto [University of Brescia, Section of Neurosurgery, Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, Brescia (Italy); University of Brescia, Section of Neuroradiology, Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, Brescia (Italy)

    2014-12-15

    The aim of this study was to prospectively investigate whether the structure of cerebral small-resistance arteries is related to cerebral perfusion parameters as measured with dynamic susceptibility-weighted contrast magnetic resonance imaging (DSC-MRI) in a selected cohort of hypertensive and normotensive patients. Ten hypertensive and 10 normotensive patients were included in the study. All patients underwent neurosurgical intervention for an intracranial tumor and were investigated with DSC-MRI at 1.5 T. Cerebral small-resistance arteries were dissected from a small portion of morphologically normal cerebral tissue and mounted on an isometric myograph for the measurement of the media-to-lumen (M/L) ratio. A quantitative assessment of cerebral blood flow (CBF) and volume (CBV) was performed with a region-of-interest approach. Correlation coefficients were calculated for normally distributed variables. The institutional review board approved the study, and informed consent was obtained from all patients. Compared with normotensive subjects, hypertensive patients had significantly lower regional CBF (mL/100 g/min) in the cortical grey matter (55.63 ± 1.90 vs 58.37 ± 2.19, p < 0.05), basal ganglia (53.34 ± 4.39 vs 58.22. ± 4.33, p < 0.05), thalami (50.65 ± 3.23 vs 57.56 ± 4.45, p < 0.01), subcortical white matter (19.32 ± 2.54 vs 22.24 ± 1.9, p < 0.05), greater M/L ratio (0.099 ± 0.013 vs 0.085 ± 0.012, p < 0.05), and lower microvessel density (1.66 ± 0.67 vs 2.52 ± 1.28, p < 0.05). A statistically significant negative correlation was observed between M/L ratio of cerebral arteries and CBF in the cortical grey matter (r = -0.516, p < 0.05), basal ganglia (r = -0.521, p < 0.05), thalami (r = -0.527 p < 0.05), and subcortical white matter (r = -0.612, p < 0.01). Our results indicate that microvascular structure might play a role in controlling CBF, with possible clinical consequences. (orig.)

  9. Changes in cerebral blood flow and psychometric indicators in veterans with early forms of chronic brain ischemia

    Directory of Open Access Journals (Sweden)

    Vasilenko Т.М.

    2015-09-01

    Full Text Available The goal is to study the cerebral blood flow and psychometric characteristics in veterans of Afghanistan with early forms of chronic brain ischemia. Material and Methods. The study included 74 veterans of the Afghan war aged from 45 to 55 years: group 1, 28 people with NPNKM; Group 2-28 patients with circulatory encephalopathy stage 1; group 3-18 healthy persons. Doppler examination of cerebral vessels was carried out on the unit «Smart-lite». Reactive and personal anxiety of patients was assessed using the scale of Spielberger, evaluation of the quality of life through the test SAN. Determining the level of neuroticism and psychoticism was conducted by the scale of neuroticism and psy-choticism. Results: The study of cerebral blood flow in the Afghan war veterans showed signs of insolvency of carotid and carotid-basilar anastomoses, hypoperfusion phenomenon with the depletion of autoregulation, violation of the outflow of venous blood at the level of the microvasculature, accompanied by cerebral arteries spasm. More than 40% of patients with early forms of chronic brain ischemia had high personal anxiety, low levels of well-being and activity, with maximum expression of dyscirculatory hypoxia. Conclusion. Readaptation of veterans of Afghanistan is accompanied by the changes in psychometric performance and the formation of the earliest forms of brain chronic ischemia associated with inadequate hemodynamics providing increased functional activity of the brain and the inefficiency of compensatory-adaptive reactions.

  10. War injuries of the blood vessels of the extremities

    Directory of Open Access Journals (Sweden)

    Radulović Svetozar

    2002-01-01

    Full Text Available Treatment results of 200 injured with the lesions of 282 magisterial blood vessels were analyzed. All were combat injuries, and the majority was caused by the fragments of explosive device. The mechanism of such the injuries produced large defects of soft tissues as well as the high level of the wound contamination, which aggravated reconstructive procedures and increased the risk of infection. In the majority of cases anatomic reconstruction of the artery was performed, and the ligature was used only in the case of graft infection and in the injuries of one artery of the lower leg or the forearm. The majority of injuries was solved by lateral suture or patch plastic, since postoperative constriction caused by those methods did not cause greater hemodynamic disorders due to the size of venous lumen. The duration of ischemic interval was of the utmost importance for the favorable final result of the treatment, as well as the adequate debridement of the wound, good soft-tissue cover of the reconstructed blood vessel and precise a traumatic technique. Total percentage of amputations was 14.5%, and all were involving the lower extremities, and were mostly caused by popliteal artery lesion.

  11. A quantitative evaluation of regional cerebral blood flow in the patients with cerebral vascular accident

    International Nuclear Information System (INIS)

    We studied the validity of a new method using 99mTc-HMPAO for quantitative evaluation of regional cerebral blood flow (rCBF) with single-photon emission computed tomography (SPECT). Subjects consisted of 20 patients with various categories of cerebral vascular accident. There were 14 males and six females. Age ranged from 33 to 88 years old with a mean of 67.9. Each category included two cerebral hemorrhages, six atherothrombotic, nine lacunar, and three cardioembolic strokes. By using the method reported by Matsuda et al., rCBF measurements were carried out at least three weeks after the insults. A total of 18 ROIs was set symmetrically on both affected and unaffected hemispheres. Data collected from the frontal, the temporal, and the occipital ROI of the unaffected hemisphere showed 50.5±10.1, 50.4±12.7, and 48.6±8.4ml/100g/min (mean±SD) respectively. Since these values were similar to those measured by other methods including PET, an average of these values was used as a control to evaluate the values of the affected regions. In the affected regions of cerebral hemorrhages, atherothrombotic, and cardioembolic stroke, rCBF showed a significant reduction. No significant decrease in rCBF was revealed in the lesions of lacunar stroke presumably because of relative small lesions. These results suggest that this simple and minimally invasive method is reliable as a quantitative measurement of rCBF and is applicable for clinical uses. (author)

  12. Mathematical Model of Blood Flow in Small Blood Vessel in the Presence of Magnetic Field

    Directory of Open Access Journals (Sweden)

    Rekha Bali

    2011-02-01

    Full Text Available A mathematical model for blood flow in the small blood vessel in the presence of magnetic field is presented in this paper. We have modeled the two phase model for the blood flow consists of a central core of suspended erythrocytes and cell-free layer surrounding the core. The system of differential equations has been solved analytically. We have obtained the result for velocity, flow rate and effective viscosity in presence of peripheral layer and magnetic field .All the result has been obtained and discussed through graphs.

  13. Effects of forskolin on cerebral blood flow: implications for a role of adenylate cyclase

    International Nuclear Information System (INIS)

    We have studied cerebral vascular effects of forskolin, a drug which stimulates adenylate cyclase and potentiates dilator effects of adenosine in other vascular beds. Our goals were to determine whether forskolin is a cerebral vasodilator and whether it potentiates cerebral vasodilator responses to adenosine. We measured cerebral blood flow with microspheres in anesthetized rabbits. Forskolin (10 micrograms/kg per min) increased blood flow (ml/min per 100 gm) from 39 +/- 5 (mean +/- S.E.) to 56 +/- 9 (p less than 0.05) in cerebrum, and increased flow to myocardium and kidney despite a decrease in mean arterial pressure. Forskolin did not alter cerebral oxygen consumption, which indicates that the increase in cerebral blood flow is a direct vasodilator effect and is not secondary to increased metabolism. We also examined effects of forskolin on the response to infusion of adenosine. Cerebral blood flow was measured during infusion of 1-5 microM/min adenosine into one internal carotid artery, under control conditions and during infusion of forskolin at 3 micrograms/kg per min i.v. Adenosine alone increased ipsilateral cerebral blood flow from 32 +/- 3 to 45 +/- 5 (p less than 0.05). Responses to adenosine were not augmented during infusion of forskolin. We conclude that forskolin is a direct cerebral vasodilator and forskolin does not potentiate cerebral vasodilator responses to adenosine

  14. No effect of angiotensin II AT(2)-receptor antagonist PD 123319 on cerebral blood flow autoregulation

    DEFF Research Database (Denmark)

    Estrup, T M; Paulson, O B; Strandgaard, S

    2001-01-01

    Blockade of the renin-angiotensin system with angiotensin-converting enzyme inhibitors (ACE-I) or angiotensin AT1-receptor antagonists shift the limits of autoregulation of cerebral blood flow (CBF) towards lower blood pressure (BP). The role of AT2-receptors in the regulation of the cerebral cir...

  15. Cilostazol reduces blood brain barrier dysfunction, white matter lesion formation and motor deficits following chronic cerebral hypoperfusion.

    Science.gov (United States)

    Edrissi, Hamidreza; Schock, Sarah C; Cadonic, Robert; Hakim, Antoine M; Thompson, Charlie S

    2016-09-01

    Cerebral small vessel disease (CSVD) is a pathological process leading to lacunar infarcts, leukoaraiosis and cerebral microbleeds. Dysfunction of the blood brain barrier (BBB) has been proposed as a mechanism in the progression cerebral small vessel disease. A rodent model commonly used to study some aspects of CSVD is bilateral common carotid artery occlusion (BCCAO) in the rat. In the present study it was determined that gait impairment, as determined by a tapered beam test, and BBB permeability increased following BCCAO. Cilostazol, a type III phosphodiesterase inhibitor, has been shown to have anti-apoptotic effects and prevent white matter vacuolation and rarefaction induced by BCCAO in rats. In this study the protective effect of cilostazol administration on the increase BBB permeability following BCCAO was determined as well as the effect on plasma levels of circulating microparticles (MPs), cerebral white matter rarefaction, glial activation and gait disturbance. The effect of cilostazol on in vitro endothelial barriers was also evaluated. Cilostazol treatment improved BBB permeability and reduced gait disturbance, visual impairment and microglial activation in optic tract following BCCAO in vivo. It also reduced the degree of cell death and the reduction in trans-endothelial electrical resistance (TEER) in artificial endothelial barriers in vitro induced by MP treatment of in vitro barriers. PMID:27350079

  16. The effect of an acute increase in central blood volume on the response of cerebral blood flow to acute hypotension.

    Science.gov (United States)

    Ogoh, Shigehiko; Hirasawa, Ai; Sugawara, Jun; Nakahara, Hidehiro; Ueda, Shinya; Shoemaker, J Kevin; Miyamoto, Tadayoshi

    2015-09-01

    The purpose of the present study was to examine whether the response of cerebral blood flow to an acute change in perfusion pressure is modified by an acute increase in central blood volume. Nine young, healthy subjects voluntarily participated in this study. To measure dynamic cerebral autoregulation during normocapnic and hypercapnic (5%) conditions, the change in middle cerebral artery mean blood flow velocity was analyzed during acute hypotension caused by two methods: 1) thigh-cuff occlusion release (without change in central blood volume); and 2) during the recovery phase immediately following release of lower body negative pressure (LBNP; -50 mmHg) that initiated an acute increase in central blood volume. In the thigh-cuff occlusion release protocol, as expected, hypercapnia decreased the rate of regulation, as an index of dynamic cerebral autoregulation (0.236 ± 0.018 and 0.167 ± 0.025 s(-1), P = 0.024). Compared with the cuff-occlusion release, the acute increase in central blood volume (relative to the LBNP condition) with LBNP release attenuated dynamic cerebral autoregulation (P = 0.009). Therefore, the hypercapnia-induced attenuation of dynamic cerebral autoregulation was not observed in the LBNP release protocol (P = 0.574). These findings suggest that an acute change in systemic blood distribution modifies dynamic cerebral autoregulation during acute hypotension. PMID:26159757

  17. EAAC1 Gene Deletion Increases Neuronal Death and Blood Brain Barrier Disruption after Transient Cerebral Ischemia in Female Mice

    Directory of Open Access Journals (Sweden)

    Bo Young Choi

    2014-10-01

    Full Text Available EAAC1 is important in modulating brain ischemic tolerance. Mice lacking EAAC1 exhibit increased susceptibility to neuronal oxidative stress in mice after transient cerebral ischemia. EAAC1 was first described as a glutamate transporter but later recognized to also function as a cysteine transporter in neurons. EAAC1-mediated transport of cysteine into neurons contributes to neuronal antioxidant function by providing cysteine substrates for glutathione synthesis. Here we evaluated the effects of EAAC1 gene deletion on hippocampal blood vessel disorganization after transient cerebral ischemia. EAAC1−/− female mice subjected to transient cerebral ischemia by common carotid artery occlusion for 30 min exhibited twice as much hippocampal neuronal death compared to wild-type female mice as well as increased reduction of neuronal glutathione, blood–brain barrier (BBB disruption and vessel disorganization. Pre-treatment of N-acetyl cysteine, a membrane-permeant cysteine prodrug, increased basal glutathione levels in the EAAC1−/− female mice and reduced ischemic neuronal death, BBB disruption and vessel disorganization. These findings suggest that cysteine uptake by EAAC1 is important for neuronal antioxidant function under ischemic conditions.

  18. Prediction of Cerebral Hyperperfusion Syndrome with Velocity Blood Pressure Index

    Directory of Open Access Journals (Sweden)

    Zhi-Chao Lai

    2015-01-01

    Full Text Available Background: Cerebral hyperperfusion syndrome is an important complication of carotid endarterectomy (CEA. An >100% increase in middle cerebral artery velocity (MCAV after CEA is used to predict the cerebral hyperperfusion syndrome (CHS development, but the accuracy is limited. The increase in blood pressure (BP after surgery is a risk factor of CHS, but no study uses it to predict CHS. This study was to create a more precise parameter for prediction of CHS by combined the increase of MCAV and BP after CEA. Methods: Systolic MCAV measured by transcranial Doppler and systematic BP were recorded preoperatively; 30 min postoperatively. The new parameter velocity BP index (VBI was calculated from the postoperative increase ratios of MCAV and BP. The prediction powers of VBI and the increase ratio of MCAV (velocity ratio [VR] were compared for predicting CHS occurrence. Results: Totally, 6/185 cases suffered CHS. The best-fit cut-off point of 2.0 for VBI was identified, which had 83.3% sensitivity, 98.3% specificity, 62.5% positive predictive value and 99.4% negative predictive value for CHS development. This result is significantly better than VR (33.3%, 97.2%, 28.6% and 97.8%. The area under the curve (AUC of receiver operating characteristic: AUC VBI = 0.981, 95% confidence interval [CI] 0.949-0.995; AUC VR = 0.935, 95% CI 0.890-0.966, P = 0.02. Conclusions: The new parameter VBI can more accurately predict patients at risk of CHS after CEA. This observation needs to be validated by larger studies.

  19. The phosphodiesterase 3 inhibitor cilostazol dilates large cerebral arteries in humans without affecting regional cerebral blood flow

    DEFF Research Database (Denmark)

    Birk, Steffen; Kruuse, Christina Rostrup; Petersen, Kenneth A;

    2004-01-01

    the middle cerebral arteries (VMCA) was measured with transcranial Doppler, and the superficial temporal and radial arteries diameters were measured with ultrasonography. During the 4-hour observation period, there was no effect on systolic blood pressure (P = 0.28), but diastolic blood pressure...

  20. Cerebral blood flow in sickle cell cerebrovascular disease

    International Nuclear Information System (INIS)

    Cerebral blood flow (CBF) has been studied by the xenon-133 (133Xe) inhalation method in 16 children with suspected sickle cell cerebrovascular disease. Abnormalities consisting of decreases in total, hemispheral, or regional CBF were found in 17 of 26 studies. Eleven studies performed immediately after stroke, transient ischemic attack, or depression of state of alertness showed abnormalities. In addition to confirming regional cerebrovascular insufficiency in children with stroke due to major cerebral artery occlusion, the method detected diffuse decrease in CBF in children with stupor, coma, and seizures who had normal angiographic findings. In contrast, six of seven studies obtained after exchange transfusion or during maintenance on hypertransfusion therapy showed normal findings. The difference between results in patients with acute neurologic disturbances and those receiving transfusion therapy was statistically significant (P less than .005). The data indicate that the 133Xe method reliably demonstrates cerebrovascular impairment in sickle cell disease. They also suggest that CBF changes in patients with sickle cell disease can be reversed by exchange transfusion and by hypertransfusion therapy. The 133Xe CBF method may be useful for following up children with sickle cell disease who are at high risk for recurrent stroke

  1. Two and Three Dimensional Blood Flow Simulations in Different Types of Blood Vessels

    Directory of Open Access Journals (Sweden)

    Balazs ALBERT

    2015-12-01

    Full Text Available In this paper we present a synthesis of our results obtained on blood flow simulation in different types of blood vessels. We present first some remarks on the wall shear stress (WSS in the case of a human abdominal aortic aneurysm (AAA, and then we concentrate on the mechanical conditions which would lead to the “rupture” of the vascular vessel with aneurysm and implicitly to a possible stroke. We also make some investigations on the Fahraeus-Lindqvist effect in arterioles. Considering an axial-symmetric reservoir full of blood and which is linked to an arteriole (with the same particular geometry, we have pointed out the concentration of the red blood cells in this arteriole towards the core of the vessel. To improve our work we have considered a real three-dimensional geometry, which is a serious jump versus our previous results, where only the axial-symmetric geometries were considered. In this respect we have reconsidered the case of a carotid artery stenosis with and without a stent.

  2. Scintigraphy of cerebral blood flow with N-isopropyl-p-[123I]-iodoamphetamine in cerebrovascular accident

    International Nuclear Information System (INIS)

    In 20 patients with cerebrovascular accident, cerebral blood flow was estimated with N-isopropyl-p-[123I]-iodoamphetamine (123I-IMP) using a rotating gamma camera, and the findings were compared with those of X-CT or angiography. 123I-IMP study demonstrated the areas of diminished cerebral blood flow in 14 cases. X-CT also demonstrated lesions in 14 cases, however, 123I-IMP study delineated the lesions more precisely corresponding to the neurological findings. In cases with cerebellar hemorrhage or reversible ischemic neurological deficit (RIND), the lesion could be established only by 123I-IMP study. It was demonstrated by 123I-IMP study that vascular stenosis or abnormal vessels seen on angiography in patients with vertebro-basilar insufficiency or venous angioma was not necessarily accompanied by diminished blood flow. It was shown that scintigraphy with 123I-IMP was a non-invasive, safe and extremely useful method to estimate the regional cerebral blood flow. (author)

  3. Portable real time analysis system for regional cerebral blood flow

    International Nuclear Information System (INIS)

    A very portable, regional cerebral blood flow (rCBF) analysis instrument system suitable for use in the operating theater during surgery is under development. Cadmium telluride (CdTe) solid state radiation detectors, an 8086 based data acquisition and communications module and a DEC Microvax computer are used so that the instrument is very compact, yet has the computational power to provide real time data analysis in the clinical environment. The instrument is currently being used at Bowman Gray School of Medicine to study rCBF during cardiopulmonary bypass surgery (CPB). Preliminary studies indicate that monitoring rCBF during this surgical procedure may provide insights into the mechanism that causes a significant fraction of these patients to suffer post operative neuropsychological deficit

  4. Portable real time analysis system for regional cerebral blood flow

    Energy Technology Data Exchange (ETDEWEB)

    Tiernan, T.; Entine, G.; Stump, D.A.; Prough, D.S.

    1988-02-01

    A very portable, regional cerebral blood flow (rCBF) analysis instrument system suitable for use in the operating theater during surgery is under development. Cadmium telluride (CdTe) solid state radiation detectors, an 8086 based data acquisition and communications module and a DEC Microvax computer are used so that the instrument is very compact, yet has the computational power to provide real time data analysis in the clinical environment. The instrument is currently being used at Bowman Gray School of Medicine to study rCBF during cardiopulmonary bypass surgery (CPB). Preliminary studies indicate that monitoring rCBF during this surgical procedure may provide insights into the mechanism that causes a significant fraction of these patients to suffer post operative neuropsychological deficit.

  5. Cerebral blood flow response to propranolol in streptozotocin diabetic rats

    DEFF Research Database (Denmark)

    Lass, Preben; Knudsen, G M

    1990-01-01

    The influence of propranolol on cerebral blood flow (CBF) was tested in streptozotocin diabetic rats and in control animals. Resting CBF values were 40% lower in the diabetic rats compared with controls. Intravenous injection of propranolol (2 mg kg-1) decreased CBF significantly in the control...... group; the CBF decreased for 15 min after propranolol injection and returned to baseline values after 90 min. In the diabetic rats, the CBF declined steadily but this decrease did not reach significance, even after 90 min. Impaired beta-adrenergic mechanisms may be an important factor in the CBF...... alterations which occur in diabetes mellitus. Further, it is suggested that an impaired CBF response may play a role in CNS lesions in diabetic patients treated with beta antagonists....

  6. Cerebral blood flow SPECT scanning in cortico-basal degeneration

    International Nuclear Information System (INIS)

    Idiopathic Parkinson's disease accounts for ca. 75% of all cases of Parkinsonism. Corticobasal degeneration is a relatively rare example of the so-called ''Parkinson-plus'' syndrome. The authors present the case of a 56-year-old woman with rigidity and atypical tremor of upper extremity followed by gait apraxia, dysarthria, bilateral pyramidal signs and myoclonus. There was no improvement after treatment with L-dopa. The disease has progressed, but the patient is still alive. On the basis of clinical data a diagnosis of corticobasal degeneration has been established. Cerebral blood flow SPECT scanning revealed diffuse hypoperfusion of left frontal lobe, antero-inferior part of the left temporal lobe and left basal ganglia. The case illustrates the usefulness of brain SPECT in atypical forma of Parkinson's disease. (author)

  7. Cerebral blood flow in normal and abnormal sleep and dreaming

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, J.S.; Ishikawa, Y.; Hata, T.; Karacan, I.

    1987-07-01

    Measurements of regional or local cerebral blood flow (CBF) by the xenon-133 inhalation method and stable xenon computerized tomography CBF (CTCBF) method were made during relaxed wakefulness and different stages of REM and non-REM sleep in normal age-matched volunteers, narcoleptics, and sleep apneics. In the awake state, CBF values were reduced in both narcoleptics and sleep apneics in the brainstem and cerebellar regions. During sleep onset, whether REM or stage I-II, CBF values were paradoxically increased in narcoleptics but decreased severely in sleep apneics, while in normal volunteers they became diffusely but more moderately decreased. In REM sleep and dreaming CBF values greatly increased, particularly in right temporo-parietal regions in subjects experiencing both visual and auditory dreaming.

  8. Cerebral blood flow in normal and abnormal sleep and dreaming

    International Nuclear Information System (INIS)

    Measurements of regional or local cerebral blood flow (CBF) by the xenon-133 inhalation method and stable xenon computerized tomography CBF (CTCBF) method were made during relaxed wakefulness and different stages of REM and non-REM sleep in normal age-matched volunteers, narcoleptics, and sleep apneics. In the awake state, CBF values were reduced in both narcoleptics and sleep apneics in the brainstem and cerebellar regions. During sleep onset, whether REM or stage I-II, CBF values were paradoxically increased in narcoleptics but decreased severely in sleep apneics, while in normal volunteers they became diffusely but more moderately decreased. In REM sleep and dreaming CBF values greatly increased, particularly in right temporo-parietal regions in subjects experiencing both visual and auditory dreaming

  9. Cerebral blood flow changes in Parkinson's disease associated with dementia

    International Nuclear Information System (INIS)

    Dementia is one of the main non-motor symptoms of Parkinson's disease (PD) and it is diagnosed in about 30% of cases. Its aetiology remains unclear and contributing factors are controversial. Dementia may be more common in old patients with severe motor symptoms and mild cognitive impairment. Clinico-pathological studies show the association between dementia in PD and the age-related group of dementias, such as AD and VaD. A valuable aid in the assessment of dementia in PD is cerebral blood flow (CBF) brain SPECT scanning. It shows three different patterns of rCBF reduction, including frontal lobe hypoperfusion, iu Alzheimer-likel type of hypoperfusion and multiple, vascular defects. The heterogeneity of rCBF reduction may reflect the multifactorial pathophysiology of dementia in PD. It may result from concomitant AD pathology, cerebrovascular disease, destruction of nigro-striato-frontal projection or may be a distinct disease of different aetiology. (author)

  10. A Functional Requirement for Astroglia in Promoting Blood Vessel Development in the Early Postnatal Brain

    OpenAIRE

    Shang Ma; Hyo Jun Kwon; Zhen Huang

    2012-01-01

    Astroglia are a major cell type in the brain and play a key role in many aspects of brain development and function. In the adult brain, astrocytes are known to intimately ensheath blood vessels and actively coordinate local neural activity and blood flow. During development of the neural retina, blood vessel growth follows a meshwork of astrocytic processes. Several genes have also been implicated in retinal astrocytes for regulating vessel development. This suggests a role of astrocytes in p...

  11. Regional cerebral blood flow in patients with hypertensive intracerebral hemorrhage

    International Nuclear Information System (INIS)

    Regional cerebral blood flow (rCBF) was measured in 36 patients with hypertensive intracerebral hemorrhage (putaminal hemorrhage) treated surgically, using the Xenon-133 intracarotid injection method. The correlations between CBF in four regions, (the hemisphere, the frontal region, the sensori-motor area and the focal area) and the duration from the operation, the conscious level, the hematoma volume and motor function were investigated. Mean cerebral blood flow (MCBF), rCBF in sensori-motor area and in the focal area showed a value below 30 ml/100g/min. for any duration after the operation within one year. However, in the frontal region rCBF tends to increase from 4 months after the operation. There was a close correlation between the conscious level and CBF, especially in the frontal region. The higher CBF was noted in the better consciousness group. In hematoma cases the larger the hematoma volume (especially those over 31 ml)the lower the CBF in all three regions. In the focal area rCBF showed the lowest value among these three regions and was dependent on the hematoma volume, while frontal region revealed the highest flow value of them all, even in cases with a hematoma volume over 81 ml. There was a significant difference in rCBF between cases with severe motor disturbance and cases with moderate motor disturbance, except in the focal area. In the frontal region rCBF coincides rather well to the degree of motor disturbance. While, rCBF in the focal area was less than 30 ml/100g/min., and showed no correlation to motor function. (J.P.N.)

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

    International Nuclear Information System (INIS)

    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 APOEε4 allele has been reported to increase risk and to lower onset age as a function of the inherited dose of the ε4 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 ε4 allele. On the contrary the relation of ε4 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 or statistical parametric mapping

  13. Modeling Cerebral Blood Flow Control During Posture Change from Sitting to Standing

    DEFF Research Database (Denmark)

    Olufsen, Mette; Tran, Hien; Ottesen, Johnny T.

    2004-01-01

    Hypertension, decreased cerebral blood flow, and diminished cerebral blood flow regulation, are among the first signs indicating the presence of cerebral vascular disease. In this paper, we will present a mathematical model that can predict blood flow and pressure during posture change from sitting...... to standing. The mathematical model uses a compartmental approach to describe pulsatile blood flow and pressure in a number of compartments representing the systemic circulation. Our model includes compartments representing the trunk and upper extremities, the lower extremities, the brain, the atria...

  14. Pattern of blood vessels in eyes with coloboma

    Directory of Open Access Journals (Sweden)

    Gopal Lingam

    2013-01-01

    Full Text Available Background: Choroidal coloboma, especially with optic disc involvement affects the blood vessel (BV pattern in the fundus. Aim: The aim of this study was to report the observations on the pattern of retinal BVs in eyes with fundus coloboma. Design: Retrospective observational study. Materials and Methods: Twenty four eyes of 19 patients with fundus coloboma and the disc involvement in the coloboma was classified according to a previous publication. Results: Four varieties of BVs were identified in the area of coloboma - BVs that were continuous with those arising from the optic disc; vessels emanating from the floor of coloboma whose continuity with central retinal artery or its branches could be indirectly established; and those emanating from the floor of coloboma whose continuity with central retinal artery could not be established. In addition, extraocular BVs were visible through the thinned sclera. The retinal BVs often traversed the coloboma to reach the normal retina. The disc itself was found to be small and had no physiological cup (if not colobomatous. Conclusions: One should be aware of the major BVs transgressing the coloboma while performing relaxing cuts in the intercalary membrane, during the surgery for retinal detachments in eyes with coloboma. Physiological cup is usually absent (when the disc is not colobomatous. Hence, any cupping in such eyes should be viewed with suspicion.

  15. The Influence of Dome Size, Parent Vessel Angle, and Coil Packing Density on Coil Embolization Treatment in Cerebral Aneurysms

    Science.gov (United States)

    Frakes, David H.; Indahlastari, Aprinda; Ryan, Justin; Babiker, M. Haithem; Nair, Priya; Parthas, Varsha

    2013-11-01

    Intracranial aneurysms (ICAs) are dilated cerebral blood vessels. Treating ICAs effectively prior rupture is crucial since their association with 45% mortality rate. Embolic coiling is the most effective ICA treatment. Series of embolic coils are deployed into the aneurysm with the intent of reaching a sufficient packing density (PD) to help seal off the ICA from circulation. While coiling is effective, treatment failures have been associated with basilar tip aneurysms (BTAs), perhaps because of their geometry. The aim of this study was to examine the effect of dome size, parent vessel (PV) angle, and PD on intraaneurysmal (IA) velocity, crossneck (CN) flow and low wall shear stress (WSS) area using simulations and experiments in idealized BTA models. IA velocity and CN flow decreased after coiling, while low WSS area increased. With increasing PD, IA velocity and CN flow were further reduced, but low WSS area had a minimal change. Coil PD had the greatest impact on post-treatment flow while dome size had a greater impact than PV angle. Overall, the role of aneurysmal geometries may vary depending on treatment goal and timing e.g., high coil PD may reduce IA velocity more effectively during early aneurysmal growth when the dome size is small. Funded by the American Heart Association.

  16. Astrocytic adaptation during cerebral angiogenesis follows the new vessel formation induced through chronic hypoxia in adult mouse cortex

    Science.gov (United States)

    Masamoto, Kazuto; Kanno, Iwao

    2014-03-01

    We examined longitudinal changes of the neuro-glia-vascular unit during cerebral angiogenesis induced through chronic hypoxia in the adult mouse cortex. Tie2-GFP mice in which the vascular endothelial cells expressed green fluorescent proteins (GFP) were exposed to chronic hypoxia, while the spatiotemporal developments of the cortical capillary sprouts and the neighboring astrocytic remodeling were characterized with repeated two-photon microscopy. The capillary sprouts appeared at early phases of the hypoxia adaptation (1-2 weeks), while the morphological changes of the astrocytic soma and processes were not detected in this phase. In the later phases of the hypoxia adaptation (> 2 weeks), the capillary sprouts created a new connection with existing capillaries, and its neighboring astrocytes extended their processes to the newly-formed vessels. The findings show that morphological adaptation of the astrocytes follow the capillary development during the hypoxia adaptation, which indicate that the newly-formed vessels provoke cellular interactions with the neighboring astrocytes to strengthen the functional blood-brain barrier.

  17. The influence of hyperoxia on regional cerebral blood flow (rCBF), regional cerebral blood volume (rCBV) and cerebral blood flow velocity in the middle cerebral artery (CBFVMCA) in human volunteers.

    Science.gov (United States)

    Kolbitsch, Christian; Lorenz, Ingo H; Hörmann, Christoph; Hinteregger, Martin; Löckinger, Alexander; Moser, Patrizia L; Kremser, Christian; Schocke, Michael; Felber, Stephan; Pfeiffer, Karl P; Benzer, Arnulf

    2002-09-01

    Conflicting results reported on the effects of hyperoxia on cerebral hemodynamics have been attributed mainly to methodical and species differences. In the present study contrast-enhanced magnetic resonance imaging (MRI) perfusion measurement was used to analyze the influence of hyperoxia (fraction of inspired oxygen (FiO2) = 1.0) on regional cerebral blood flow (rCBF) and regional cerebral blood volume (rCBV) in awake, normoventilating volunteers (n = 19). Furthermore, the experiment was repeated in 20 volunteers for transcranial Doppler sonography (TCD) measurement of cerebral blood flow velocity in the middle cerebral artery (CBFV(MCA)). When compared to normoxia (FiO2 = 0.21), hyperoxia heterogeneously influenced rCBV (4.95 +/- 0.02 to 12.87 +/- 0.08 mL/100g (FiO2 = 0.21) vs. 4.50 +/- 0.02 to 13.09 +/- 0.09 mL/100g (FiO2 = 1.0). In contrast, hyperoxia diminished rCBF in all regions (68.08 +/- 0.38 to 199.58 +/- 1.58 mL/100g/min (FiO2 = 0.21) vs. 58.63 +/- 0.32 to 175.16 +/- 1.51 mL/100g/min (FiO2 = 1.0)) except in parietal and left frontal gray matter. CBFV(MCA) remained unchanged regardless of the inspired oxygen fraction (62 +/- 9 cm/s (FiO2 = 0.21) vs. 64 +/- 8 cm/s (FiO2 = 1.0)). Finding CBFV(MCA) unchanged during hyperoxia is consistent with the present study's unchanged rCBF in parietal and left frontal gray matter. In these fronto-parietal regions predominantly fed by the middle cerebral artery, the vasoconstrictor effect of oxygen was probably counteracted by increased perfusion of foci of neuronal activity controlling general behavior and arousal. PMID:12413599

  18. 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...

  19. Correlations of cerebral blood flow with language function in aphasic patients following cerebral infarction

    International Nuclear Information System (INIS)

    To elucidate the participation of the brain regions in language function, cerebral blood flow (CBF) which were measured with positron emission tomography (PET) were compared with the language scores based on the standard language test for aphasics in 97 right-handed patients with aphasia due to cerebral infarction. PET studies were performed on 71.4±107.3 days after onset. By the linear regression analysis, the aphasic scores were correlated with the regional CBF from 55 brain regions. CBF from the left frontal, left temporal, and left parietal lobes significantly correlated with language scores of auditory comprehension, speaking, reading, writing, calculation, and repetition. Highly significant correlation was obtained from the left posterior inferior frontal, superior temporal, supramarginal and angular gyri. CBF from the right inferior frontal, right superior temporal, right parahippocampal and right anterior cingulate gyri also correlated with the auditory comprehension, speaking and reading. Accordingly, in addition to the classical language areas which play an essential roles in language function, the extensive areas in the left hemisphere and some part of the right hemisphere may be related to the language processing and recovery from aphasia. (author)

  20. A Modeling of Cerebral Blood Flow Changes due to Head Motion for fNIRS

    Science.gov (United States)

    Takahashi, Kosuke; Tanaka, Takayuki; Nara, Hiroyuki; Kaneko, Shun'ichi; Inoue, Masao; Shimizu, Shunji; Kojima, Satoru

    2013-04-01

    A method is proposed for measuring brain activity during exercises involving head motion by using functional near-infrared spectroscopy (fNIRS), which investigates cerebral hemodynamics. Obtaining measurements during exercise is difficult because cerebral blood flow changes due to the head motion component (HMC), in addition to neural activity. HMC is an undesirable artifact in the measurement of hemodynamic response caused by neural activity, and as such, it must be estimated and eliminated. In our experiments, cerebral blood flow and head motion were measured during repeated passive forward bending of the subjects. Head motion was measured by 3-D motion capture, and HMC was estimated by deriving a relation between head motion and cerebral blood flow, where the pitch angle was found to be suitable for estimating HMC. In this research, an assumption was made that cerebral blood flow caused by neural activity and that caused by postural change were additive, and thus HMC was eliminated by subtraction.

  1. Cerebral blood flow in migraine and cortical spreading depression

    International Nuclear Information System (INIS)

    In a series of migraine patients, carotid arteriography was carried out as part of the clinical evaluation. Nine patients developed a migrainous attack with focal neurological symptoms and headache after the angiography and during the subsequent, ongoing regional cerebral blood flow rCBF study. rCBF was measured by bolus injection of Xenon133 into the internal carotid artery and a gamma camera with 254 collimated scintillation detectors covering the lateral aspect of the hemisphere. This technique depicts rCBF mainly at the level of the superficial cortex, with no depth resolution. The resolution is 1 cm2 providing detailed spatial information of the cortical blood flow. Other methods for measuring local blood flow in animal and man employ a radioactive, freely diffusible tracer, in combination with an autoradiographic technique for the assessment of the tissue concentration, the so-called autoradiographic methods. In the series of patients with spontaneous migraine, rCBF was estimated using an in-vivo application of the autoradiographic principle. Xenon133 was administered by inhalation and the time course of the arterial concentration curve was assessed by a scintillation detector over the upper right lung, since the arterial curve has been found to follow the shape of the lung curve. The rCBF was studied accompanying cortical spreading depression in rat experiments to evaluate whether this phenomenon could explain the blood flow changes in migraine. (14C) iodoantipyrine was given as an intravenous bolus injection and the brain content of indicator was determined by tissue sample or autoradiography after 10 or 20 seconds of isotope circulation. The conditions of the autoradiographic methods are that the flow remains constant within the period of measuring, and that the region under study is homogenous with regard to flow and λ. (EG)

  2. MRI of cerebral blood flow under hyperbaric conditions in rats.

    Science.gov (United States)

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

    2016-07-01

    Hyperbaric oxygen (HBO) therapy has a number of clinical applications. However, the effects of acute HBO on basal cerebral blood flow (CBF) and neurovascular coupling are not well understood. This study explored the use of arterial spin labeling MRI to evaluate changes in baseline and forepaw stimulus-evoked CBF responses in rats (n = 8) during normobaric air (NB), normobaric oxygen (NBO) (100% O2 ), 3 atm absolute (ATA) hyperbaric air (HB) and 3 ATA HBO conditions. T1 was also measured, and the effects of changes in T1 caused by increasing oxygen on the CBF calculation were investigated. The major findings were as follows: (i) increased inhaled oxygen concentrations led to a reduced respiration rate; (ii) increased dissolved paramagnetic oxygen had significant effects on blood and tissue T1 , which affected the CBF calculation using the arterial spin labeling method; (iii) the differences in blood T1 had a larger effect than the differences in tissue T1 on CBF calculation; (iv) if oxygen-induced changes in blood and tissue T1 were not taken into account, CBF was underestimated by 33% at 3 ATA HBO, 10% at NBO and HBO, HB and NBO were similar (p > 0.05) and all were higher than CBF under NB by ~40% (p HBO, similar to NB, supporting the notion that activation-induced CBF regulation in the brain does not operate through an oxygen-sensing mechanism. CBF MRI provides valuable insights into the effects of oxygen on basal CBF and neurovascular coupling under hyperbaric conditions. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27192391

  3. Selective α1-adrenergic blockade disturbs the regional distribution of cerebral blood flow during static handgrip exercise.

    Science.gov (United States)

    Fernandes, Igor A; Mattos, João D; Campos, Monique O; Machado, Alessandro C; Rocha, Marcos P; Rocha, Natalia G; Vianna, Lauro C; Nobrega, Antonio C L

    2016-06-01

    Handgrip-induced increases in blood flow through the contralateral artery that supplies the cortical representation of the arm have been hypothesized as a consequence of neurovascular coupling and a resultant metabolic attenuation of sympathetic cerebral vasoconstriction. In contrast, sympathetic restraint, in theory, inhibits changes in perfusion of the cerebral ipsilateral blood vessels. To confirm whether sympathetic nerve activity modulates cerebral blood flow distribution during static handgrip (SHG) exercise, beat-to-beat contra- and ipsilateral internal carotid artery blood flow (ICA; Doppler) and mean arterial pressure (MAP; Finometer) were simultaneously assessed in nine healthy men (27 ± 5 yr), both at rest and during a 2-min SHG bout (30% maximal voluntary contraction), under two experimental conditions: 1) control and 2) α1-adrenergic receptor blockade. End-tidal carbon dioxide (rebreathing system) was clamped throughout the study. SHG induced increases in MAP (+31.4 ± 10.7 mmHg, P 0.05). The reduction in ipsilateral ICA vascular conductance (VC) was greater compared with contralateral ICA (contralateral: -0.8 ± 0.8 vs. ipsilateral: -2.6 ± 1.3 ml·min(-1)·mmHg(-1), P 0.05) and decreases in VC (contralateral: -0.4 ± 0.7 vs. ipsilateral: -0.4 ± 1.0 ml·min(-1)·mmHg(-1), P > 0.05). These findings indicate a role of sympathetic nerve activity in the regulation of cerebral blood flow distribution during SHG. PMID:27016578

  4. Cerebral blood flow effects of acute intravenous heroin administration.

    Science.gov (United States)

    Kosel, Markus; Noss, Roger S; Hämmig, Robert; Wielepp, Peter; Bundeli, Petra; Heidbreder, Rebeca; Kinser, Jane A; Brenneisen, Rudolf; Fisch, Hans-Ulrich; Kayser, Sarah; Schlaepfer, Thomas E

    2008-04-01

    We examined acute effects of intravenous diacetylmorphine (heroin) administration - which induces a characteristic biphasic response: A short rush-sensation associated with intense pleasurable feelings followed by a subjectively different period of euphoria on cerebral blood flow. This was assessed in nine male heroin dependent patients participating in a heroin maintenance program in a setting resembling everyday pattern of heroin abuse. 99mTc-HMPAO was administered 45 s (rush) and 15 min (euphoria) after administration of i.v. heroin and 45 s after administration of saline (placebo). Plasma concentration of diacetylmorphine and its metabolites were measured with high-pressure liquid chromatography (HPLC). Compared to the euphoria condition, rush was associated with blood flow increase in the left posterior cerebellar lobe, left anterior cingulate gyrus and right precuneus. Our results are in line with recent reports indicating that the cerebellum is an important component in functional brain systems subserving sensory and motor integration, learning, modulation of affect, motivation and social behaviour, which all play important roles in reinforcing properties of opioids. PMID:18207374

  5. Cerebrovascular hemodynamics in patients with cerebral arteriosclerosis

    Institute of Scientific and Technical Information of China (English)

    Jianbo Yang; Changcong Cui; Chengbin Wu

    2011-01-01

    The present study observed hemodynamic changes in 26 patients with cerebral arteriosclerosis using a cerebral circulation dynamics detector and transcranial Doppler.In patients with cerebral arteriosclerosis the blood supply and flow rate in the bilateral carotid arteries and the blood flow rate in the anterior cerebral and middle cerebral arteries were similar to normal controls, but the cerebral vascular resistance, critical pressure and pulsatility index were increased, and cerebral arterial elasticity and cerebral blood flow autoregulation were decreased.Compared with the lesioned hemisphere of patients with cerebral infarction, the total blood supply and blood flow rate of patients with cerebral arteriosclerosis were higher.Compared with normal subjects, patients with cerebral arteriosclerosis exhibited cognitive disturbances, mainly in short-term memory, attention, abstract capability, and spatial and executive dysfunction.Results showed that cerebral arteriosclerosis does not directly affect the blood supply of a cerebral hemisphere, but affects cognitive function.The increased cerebral vascular resistance and reduced autoregulation of cerebral blood vessels may be important hemodynamic mechanisms of arteriosclerosis-induced cerebral infarction.

  6. Comprehensive gene expression profiling reveals synergistic functional networks in cerebral vessels after hypertension or hypercholesterolemia.

    Directory of Open Access Journals (Sweden)

    Wei-Yi Ong

    Full Text Available Atherosclerotic stenosis of cerebral arteries or intracranial large artery disease (ICLAD is a major cause of stroke especially in Asians, Hispanics and Africans, but relatively little is known about gene expression changes in vessels at risk. This study compares comprehensive gene expression profiles in the middle cerebral artery (MCA of New Zealand White rabbits exposed to two stroke risk factors i.e. hypertension and/or hypercholesterolemia, by the 2-Kidney-1-Clip method, or dietary supplementation with cholesterol. Microarray and Ingenuity Pathway Analyses of the MCA of the hypertensive rabbits showed up-regulated genes in networks containing the node molecules: UBC (ubiquitin, P38 MAPK, ERK, NFkB, SERPINB2, MMP1 and APP (amyloid precursor protein; and down-regulated genes related to MAPK, ERK 1/2, Akt, 26 s proteasome, histone H3 and UBC. The MCA of hypercholesterolemic rabbits showed differentially expressed genes that are surprisingly, linked to almost the same node molecules as the hypertensive rabbits, despite a relatively low percentage of 'common genes' (21 and 7% between the two conditions. Up-regulated common genes were related to: UBC, SERPINB2, TNF, HNF4A (hepatocyte nuclear factor 4A and APP, and down-regulated genes, related to UBC. Increased HNF4A message and protein were verified in the aorta. Together, these findings reveal similar nodal molecules and gene pathways in cerebral vessels affected by hypertension or hypercholesterolemia, which could be a basis for synergistic action of risk factors in the pathogenesis of ICLAD.

  7. Blood Vessel Normalization in the Hamster Oral Cancer Model for Experimental Cancer Therapy Studies

    Energy Technology Data Exchange (ETDEWEB)

    Ana J. Molinari; Romina F. Aromando; Maria E. Itoiz; Marcela A. Garabalino; Andrea Monti Hughes; Elisa M. Heber; Emiliano C. C. Pozzi; David W. Nigg; Veronica A. Trivillin; Amanda E. Schwint

    2012-07-01

    Normalization of tumor blood vessels improves drug and oxygen delivery to cancer cells. The aim of this study was to develop a technique to normalize blood vessels in the hamster cheek pouch model of oral cancer. Materials and Methods: Tumor-bearing hamsters were treated with thalidomide and were compared with controls. Results: Twenty eight hours after treatment with thalidomide, the blood vessels of premalignant tissue observable in vivo became narrower and less tortuous than those of controls; Evans Blue Dye extravasation in tumor was significantly reduced (indicating a reduction in aberrant tumor vascular hyperpermeability that compromises blood flow), and tumor blood vessel morphology in histological sections, labeled for Factor VIII, revealed a significant reduction in compressive forces. These findings indicated blood vessel normalization with a window of 48 h. Conclusion: The technique developed herein has rendered the hamster oral cancer model amenable to research, with the potential benefit of vascular normalization in head and neck cancer therapy.

  8. Cerebral blood flow during cardiopulmonary bypass in pediatric cardiac surgery: the role of transcranial Doppler – a systematic review of the literature

    Directory of Open Access Journals (Sweden)

    Sanders Stephen P

    2006-12-01

    Full Text Available Abstract Background Transcranial Doppler Ultrasound (TCD is a sensitive, real time tool for monitoring cerebral blood flow velocity (CBFV. This technique is fast, accurate, reproducible and noninvasive. In the setting of congenital heart surgery, TCD finds application in the evaluation of cerebral blood flow variations during cardiopulmonary bypass (CPB. Methodology We performed a search on human studies published on the MEDLINE using the keyword "trans cranial Doppler" crossed with "pediatric cardiac surgery" AND "cardio pulmonary by pass", OR deep hypothermic cardiac arrest", OR "neurological monitoring". Discussion Current scientific evidence suggests a good correlation between changes in cbral blood flow and mean cerebral artery (MCA blood flow velocity. The introduction of Doppler technology has allowed an accurate monitorization of cerebral blood flow (CBF during circulatory arrest and low-flow CPB. TCD has also been utilized in detecting cerebral emboli, improper cannulation or cross clamping of aortic arch vessels. Limitations of TCD routine utilization are represented by the need of a learning curve and some experience by the operators, as well as the need of implementing CBF informations with, for example, data on brain tissue oxygen delivery and consumption. Conclusion In this light, TCD plays an essential role in multimodal neurological monitorization during CPB (Near Infrared Spectroscopy, TCD, processed electro encephalography that, according to recent studies, can help to significantly improve neurological outcome after cardiac surgery in neonates and pediatric patients.

  9. Type of aphasia and regional cerebral blood flow

    International Nuclear Information System (INIS)

    In 40 patients with aphasia due to cerebral infarction, regional cerebral blood flow (rCBF) was measured after 2 months of ictus with 133Xe inhalation method. There were 18 cases with motor aphasia and 22 with sensory aphasia. On the measurements of rCBF, 3 detectors were placed over frontal region (group F), 3 over temporal region (group T), and remaining 3 over parietal region (group P), of the dominant hemisphere. The flow values were compared with the rCBF values obtained from 21 control subjects who had no abnormality in CT scan and on neurological examinations. The control subjects revealed the hyperfrontal pattern of flow distribution; rCBF values in groups F, T and P, which were expressed as an initial slope index, were 50.0 +- 4.8, 48.0 +- 5.1 and 47.4 +- 4.5, respectively. The hyperfrontal pattern was absent in cases with motor aphasia. In this group, rCBF in groups F, T and P were 42.0 +- 8.3, 44.7 +- 8.4 and 41.0 +- 8.5, respectively, and rCBF in frontal region was significantly reduced compared with that in the control group. In sensory aphasia, rCBF values in groups F, T and P were all significantly reduced compared to the controls showing 44.0 +- 5.7, 42.8 +- 5.1 and 40.6 +- 5.4, respectively. In this group, the hyperfrontal pattern was maintained at a low flow level. When absolute rCBF values were compared between motor and sensory aphasia, there was no significant difference between these 2 groups. However, regional flow distribution in motor aphasia was significantly different from that of sensory aphasia, and the cases having the lowest value in group F were more frequently found in the former than in the latter. (J.P.N.)

  10. Alterations of the cerebral cortex in sporadic small vessel disease: A systematic review of in vivo MRI data.

    Science.gov (United States)

    Peres, Roxane; De Guio, François; Chabriat, Hugues; Jouvent, Eric

    2016-04-01

    Cerebral small vessel diseases of the brain are a major determinant of cognitive impairment in the elderly. In small vessel diseases, the most easily identifiable lesions, both at post-mortem evaluation and magnetic resonance imaging, lie in subcortical areas. However, recent results obtained post-mortem, particularly in severe cases, have highlighted the burden of cortex lesions such as microinfarcts and diffuse neuronal loss. The recent development of image post-processing methods allows now assessing in vivo multiple aspects of the cerebral cortex. This systematic review aimed to analyze in vivo magnetic resonance imaging studies evaluating cortex alterations at different stages of small vessel diseases. Studies assessing the relationships between small vessel disease magnetic resonance imaging markers obtained at the subcortical level and cortex estimates were reviewed both in community-dwelling elderly and in patients with symptomatic small vessel diseases. Thereafter, studies analyzing cortex estimates in small vessel disease patients compared with healthy subjects were evaluated. The results support that important cortex alterations develop along the course of small vessel diseases independently of concomitant neurodegenerative processes. Easy detection and quantification of cortex changes in small vessel diseases as well as understanding their underlying mechanisms are challenging tasks for better understanding cognitive decline in small vessel diseases. PMID:26787108

  11. Anxiety and cerebral blood flow during behavioral challenge. Dissociation of central from peripheral and subjective measures

    Energy Technology Data Exchange (ETDEWEB)

    Zohar, J.; Insel, T.R.; Berman, K.F.; Foa, E.B.; Hill, J.L.; Weinberger, D.R.

    1989-06-01

    To investigate the relationship between anxiety and regional cerebral blood flow, we administered behavioral challenges to 10 patients with obsessive-compulsive disorder while measuring regional cerebral blood flow with the xenon 133 inhalation technique. Each patient was studied under three conditions: relaxation, imaginal flooding, and in vivo (actual) exposure to the phobic stimulus. Subjective anxiety, obsessive-compulsive ratings, and autonomic measures (heart rate, blood pressure) increased significantly, but respiratory rate and PCO/sub 2/ did not change across the three conditions. Regional cerebral blood flow increased slightly (in the temporal region) during imaginal flooding, but decreased markedly in several cortical regions during in vivo exposure, when anxiety was highest by subjective and peripheral autonomic measures. These results demonstrate that intense anxiety can be associated with decreased rather than increased cortical perfusion and that ostensibly related states of anxiety (eg, anticipatory and obsessional anxiety) may be associated with opposite effects on regional cerebral blood flow.

  12. Anxiety and cerebral blood flow during behavioral challenge. Dissociation of central from peripheral and subjective measures

    International Nuclear Information System (INIS)

    To investigate the relationship between anxiety and regional cerebral blood flow, we administered behavioral challenges to 10 patients with obsessive-compulsive disorder while measuring regional cerebral blood flow with the xenon 133 inhalation technique. Each patient was studied under three conditions: relaxation, imaginal flooding, and in vivo (actual) exposure to the phobic stimulus. Subjective anxiety, obsessive-compulsive ratings, and autonomic measures (heart rate, blood pressure) increased significantly, but respiratory rate and PCO2 did not change across the three conditions. Regional cerebral blood flow increased slightly (in the temporal region) during imaginal flooding, but decreased markedly in several cortical regions during in vivo exposure, when anxiety was highest by subjective and peripheral autonomic measures. These results demonstrate that intense anxiety can be associated with decreased rather than increased cortical perfusion and that ostensibly related states of anxiety (eg, anticipatory and obsessional anxiety) may be associated with opposite effects on regional cerebral blood flow

  13. Pericyte coverage of abnormal blood vessels in myelofibrotic bone marrows

    DEFF Research Database (Denmark)

    Zetterberg, Eva; Vannucchi, Alessandro M; Migliaccio, Anna Rita;

    2007-01-01

    BACKGROUND AND OBJECTIVES: Myelofibrotic bone marrow displays abnormal angiogenesis but the pathogenic mechanisms of this are poorly understood. Since pericyte abnormalities are described on solid tumor vessels we studied whether vessel morphology and pericyte coverage in bone marrow samples from...

  14. Blood Vessel Deformations on Microsecond Time Scales by Ultrasonic Cavitation

    OpenAIRE

    Chen, Hong; Kreider, Wayne; Brayman, Andrew A.; Bailey, Michael R.; Matula, Thomas J.

    2011-01-01

    Transient interactions among ultrasound, microbubbles, and microvessels were studied using high-speed photomicrography. We observed liquid jets, vessel distention (motion outward against the surrounding tissue), and vessel invagination (motion inward toward the lumen). Contrary to current paradigms, liquid jets were directed away from the nearest vessel wall and invagination exceeded distention. These observations provide insight into the mechanics of bubble-vessel interactions, which appear ...

  15. Glycopyrrolate abolishes the exercise-induced increase in cerebral perfusion in humans

    DEFF Research Database (Denmark)

    Seifert, Thomas; Fisher, James P; Young, Colin N;

    2010-01-01

    Brain blood vessels contain muscarinic receptors that are important for cerebral blood flow (CBF) regulation, but whether a cholinergic receptor mechanism is involved in the exercise-induced increase in cerebral perfusion or affects cerebral metabolism remains unknown. We evaluated CBF and cerebr...... abolished by glycopyrrolate (P <0.05). Thus, during both cycling and static handgrip, a cholinergic receptor mechanism is important for the exercise-induced increase in cerebral perfusion without affecting the cerebral metabolic rate for oxygen....

  16. Relationship between abnormal blood rheology and development and recovery of hypertension and cerebral infarction%血液流变学异常与高血压和脑梗死发生、转归的相关性

    Institute of Scientific and Technical Information of China (English)

    赵刚

    2002-01-01

    Background:Increased blood pressure in hypertension is related to vessels resistance,cardiac output,as well as blood viscosity.Stroke is common following hypertension.A number of studies reported that abnormal blood rheology was frequent in stroke suggesting correlation of blood rheology with onset,development,recovery of hypertension.Hypertension is the most one of independent risk factors of stroke.In the current paper,we investigated pathogenesis and development of hypertension and cerebral infarction to provide principle foundation for early prevention and treatment of cerebral infarciton.

  17. Biological and engineering design considerations for vascular tissue engineered blood vessels (TEBVs)

    OpenAIRE

    Fernandez, Cristina E.; Achneck, Hardean E.; Reichert, William M.; Truskey, George A.

    2014-01-01

    Considerable advances have occurred in the development of tissue-engineered blood vessels (TEBVs) to repair or replace injured blood vessels, or as in vitro systems for drug toxicity testing. Here we summarize approaches to produce TEBVs and review current efforts to (1) identify suitable cell sources for the endothelium and vascular smooth muscle cells, (2) design the scaffold to mimic the arterial mechanical properties and (3) regulate the functional state of the cells of the vessel wall. I...

  18. 脑梗死患者脑血管血液动力学变化与功能障碍相关性研究%Correlation of hemodynamic change of cerebral vessels and functional disturbance in cerebral infarction patient

    Institute of Scientific and Technical Information of China (English)

    王伯良; 王俊卿

    2001-01-01

    Objective To observe and investigate the correlation of hemodynamic change of cerebral vessels and functional disturbance in cerebral infarction patient.Methods To investigate hemodynamic characters of cerebral vessels in every type and every group patients via comparing cerebral infarction group(observe group)with control group,comparing stage of recovery with early stage, sever, moderate, mild degree in observe group.Results Apparent hemodynamic change was observed in above 94.10% cerebral infarction patients. The more apparent the hemodynamic change,the severer the functional disturbance.Conclusion The hemodynamic change of cerebral vessels is the predictive index of state of illness and prognosis of cerebral infarction patient.Clinical doctor should pay enough attention to modify it in treatment.

  19. Timing and topography of cerebral blood flow, aura, and headache during migraine attacks

    DEFF Research Database (Denmark)

    Olesen, J; Friberg, L; Olsen, T S; Iversen, Helle Klingenberg; Lassen, N A; Andersen, A R; Karle, A

    1990-01-01

    Ten years of study has resulted in considerable but fragmented knowledge about regional cerebral blood flow in migraine with aura (classic migraine). In the present study, the number of repeatedly studied patients (n = 63) was large enough to determine statistically significant sequences of event...... nociceptors. Bilateral headache caused by a unilateral cerebral disturbance may be explained by recent neuroanatomical and neurophysiological findings....

  20. The effect of phenylephrine on arterial and venous cerebral blood flow in healthy subjects

    DEFF Research Database (Denmark)

    Ogoh, Shigehiko; Sato, Kohei; Fisher, James P;

    2011-01-01

    Sympathetic regulation of the cerebral circulation remains controversial. Although intravenous phenylephrine (PE) infusion reduces the near-infrared spectroscopy (NIRS)-determined measure of frontal lobe oxygenation (S(c) O(2) ) and increases middle cerebral artery mean blood velocity (MCA V...

  1. An Experimental Study to Replace the Thoracic Descending Aorta for Pigs with a Self-Made Sutureless Blood Vessel

    OpenAIRE

    Song, Fenglin; Zhou, Wenwu; Tang, Tao; Li, Xiaobing; Wu, Xiaoming; Yang, Jinfu

    2014-01-01

    To simplify the procedure of blood vessel replacement operation and shorten the vascular anastomosis time, we developed a special artificial blood vessel which can be connected to native blood vessels without suture. The self-made sutureless blood vessel (SMSBV) was made from two titanium connectors and a Gore-Tex graft. To investigate blood compatibility and histocompatibility of the SMSBV, we carried thoracic descending aorta replacement using either SMSBV or Gore-Tex, respectively, in pigs...

  2. An Experimental Study to Replace the Thoracic Descending Aorta for Pigs with a Self-Made Sutureless Blood Vessel

    OpenAIRE

    2014-01-01

    To simplify the procedure of blood vessel replacement operation and shorten the vascular anastomosis time, we developed a special artificial blood vessel which can be connected to native blood vessels without suture. The self-made sutureless blood vessel (SMSBV) was made from two titanium connectors and a Gore-Tex graft. To investigate blood compatibility and histocompatibility of the SMSBV, we carried thoracic descending aorta replacement using either SMSBV or Gore-Tex,...

  3. Tumor blood vessels formation in osteosarcoma:vasculogenesis mimicry

    Institute of Scientific and Technical Information of China (English)

    蔡宣松; 贾永伟; 梅炯; 汤如勇

    2004-01-01

    Background Osteosarcoma is characterized by high neovascularization and a high propensity for metastasis through bloodstream. This study was to examine whether there is evidence for vasculogenic mimicry in osteosarcoma and to illustrate mechanism of tumor blood vessels formation in osteosarcoma.Methods Osteosarcoma cell lines (U-2OS) were tested for their ability to form tubular networks in three-dimensional culture containing type Ⅰ collagen. The structures of the tubular networks were observed with phase contrast microscope and transmission electron microscope (TEM). Morphometric studies using hematoxylin and eosin (HE) stain and CD31 immunohistochemical stain to show tumor-lined channels in human osteosarcoma were also performed.Results Observation with light microscope and TEM showed that highly aggressive osteosarcoma cell lines (U-2OS) formed networks containing channels when grown in three-dimensional culture containing type Ⅰ collagen, in the absence of endothelial cells or fibroblasts. Morphometric observation using HE stain and CD31 immunohistochemical stain showed that tumor cell-lined channels were also detected in vivo in osteosarcoma; by comparison, all vascular areas in the pedicel of osteochondroma or outside osteochondroma were endothelial-lined.Conclusion These observations strongly suggest that aggressive osteosarcoma cells may generate vascular channels that facilitate tumor perfusion independent of tumor angiogenesis and have the ability of vasculogenic mimicry.

  4. Transmitted ultrasound pressure variation in micro blood vessel phantoms.

    Science.gov (United States)

    Qin, Shengping; Kruse, Dustin E; Ferrara, Katherine W

    2008-06-01

    Silica, cellulose and polymethylmethacrylate tubes with inner diameters of ten to a few hundred microns are commonly used as blood vessel phantoms in in vitro studies of microbubble or nanodroplet behavior during insonation. However, a detailed investigation of the ultrasonic fields within these micro-tubes has not yet been performed. This work provides a theoretical analysis of the ultrasonic fields within micro-tubes. Numerical results show that for the same tube material, the interaction between the micro-tube and megaHertz-frequency ultrasound may vary drastically with incident frequency, tube diameter and wall thickness. For 10 MHz ultrasonic insonation of a polymethylmethacrylate (PMMA) tube with an inner diameter of 195 microm and an outer diameter of 260 microm, the peak pressure within the tube can be up to 300% of incident pressure amplitude. However, using 1 MHz ultrasound and a silica tube with an inner diameter of 12 microm and an outer diameter of 50 microm, the peak pressure within the tube is only 12% of the incident pressure amplitude and correspondingly, the spatial-average-time-average intensity within the tube is only 1% of the incident intensity. PMID:18395962

  5. Clinical studies on cerebral blood flow in chronic subdural hematoma

    International Nuclear Information System (INIS)

    Cerebral blood flow (CBF) and clinical symptoms were examined between pre- and post-operations in twenty-four patients with unilateral chronic subdural hematoma. The following results were obtained by intravenous 133Xe method : 1. There was a reducing tendency of the CBF (hemisphere) on hematoma side, in most cases. While, the groups of headache and disturbances of consciousness did not give a laterality between hematoma and opposite side without the group of hemiparesis. 2. The absolute values of the CBF in the groups of headache and disturbances of consciousness were correlated with the clinical symptoms. In the group of hemiparesis, the laterality between hematoma and opposite side was correlated with the clinical symptoms. 3. In the group of hemiparesis, the F-flow (fast-flow) had sensitive reaction more than the ISI (initial slope index) with symptomatic improvement. 4. It was found that there was not an increase in the absolute value of the CBF, which was under the normal limit between pre- and post-operations in the case without improvement. By SPECT (Method of IMP), the following results were obtained : 1. There was the area of defect at the location of hematoma and the CBF tended to reduce at the subcortical white matter and at the basal ganglia of hematoma side. 2. The CBF of the contralateral hematoma side in the hemisphere of cerebellum was also tended to reduce. (author)

  6. Functional laser speckle imaging of cerebral blood flow under hypothermia

    Science.gov (United States)

    Li, Minheng; Miao, Peng; Zhu, Yisheng; Tong, Shanbao

    2011-08-01

    Hypothermia can unintentionally occur in daily life, e.g., in cardiovascular surgery or applied as therapeutics in the neurosciences critical care unit. So far, the temperature-induced spatiotemporal responses of the neural function have not been fully understood. In this study, we investigated the functional change in cerebral blood flow (CBF), accompanied with neuronal activation, by laser speckle imaging (LSI) during hypothermia. Laser speckle images from Sprague-Dawley rats (n = 8, male) were acquired under normothermia (37°C) and moderate hypothermia (32°C). For each animal, 10 trials of electrical hindpaw stimulation were delivered under both temperatures. Using registered laser speckle contrast analysis and temporal clustering analysis (TCA), we found a delayed response peak and a prolonged response window under hypothermia. Hypothermia also decreased the activation area and the amplitude of the peak CBF. The combination of LSI and TCA is a high-resolution functional imaging method to investigate the spatiotemporal neurovascular coupling in both normal and pathological brain functions.

  7. Automated computational framework of blood vessel quantification in chick chorioallantoic membrane angiogenesis

    Science.gov (United States)

    Shi, Peng; Hong, Jinsheng; Huang, Yue; Zhang, Zhenhuan; Zhang, Mei; Zhang, Lurong

    2014-10-01

    Chick chorioallantoic membrane (CAM) angiogenesis assay has been widely used for finding drugs targeting new blood vessel development in cancer research. In addition to the setup materials and protocols, laboratory findings depend on the quantification and analysis of microscopic blood vessel images. However, it is still a challenging problem because of the high complexity of blood vessel branching structures. We applied preprocessing on CAM microscopic images by keeping the integrity of minor branches in the vessel structure. We then proposed an efficient way to automatically extract blood vessel centerlines based on vector tracing starting from detected seed points. Finally, all branches were coded to construct an abstract model of the branching structure, which enabled more accurate modeling for in-depth analysis. The framework was applied in quantifying Icaritin (ICT) inhibition effects on angiogenesis in a CAM model. Experimental results showed the high accuracy in blood vessel quantification and modeling compared with semimanual measurements. Meanwhile, a set of blood vessel growth indicators were extracted to provide fully automated analysis for angiogenesis assays. Further analysis proved that ICT took effect in a dose-dependent manner which could be applied in suppressing tumor blood vessel growth.

  8. Automated computational framework of blood vessel quantification in chick chorioallantoic membrane angiogenesis.

    Science.gov (United States)

    Shi, Peng; Hong, Jinsheng; Huang, Yue; Zhang, Zhenhuan; Zhang, Mei; Zhang, Lurong

    2014-01-01

    Chick chorioallantoic membrane (CAM) angiogenesis assay has been widely used for finding drugs targeting new blood vessel development in cancer research. In addition to the setup materials and protocols, laboratory findings depend on the quantification and analysis of microscopic blood vessel images. However, it is still a challenging problem because of the high complexity of blood vessel branching structures. We applied preprocessing on CAM microscopic images by keeping the integrity of minor branches in the vessel structure. We then proposed an efficient way to automatically extract blood vessel centerlines based on vector tracing starting from detected seed points. Finally, all branches were coded to construct an abstract model of the branching structure, which enabled more accurate modeling for in-depth analysis. The framework was applied in quantifying Icaritin (ICT) inhibition effects on angiogenesis in a CAM model. Experimental results showed the high accuracy in blood vessel quantification and modeling compared with semimanual measurements. Meanwhile, a set of blood vessel growth indicators were extracted to provide fully automated analysis for angiogenesis assays. Further analysis proved that ICT took effect in a dose-dependent manner which could be applied in suppressing tumor blood vessel growth. PMID:25277148

  9. 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)

  10. The effect of ergotamine and dihydroergotamine on cerebral blood flow in man

    DEFF Research Database (Denmark)

    Andersen, A R; Tfelt-Hansen, P; Lassen, N A

    1987-01-01

    The effects of ergotamine and dihydroergotamine on cerebral blood flow was investigated 4 hours after i.v. injection as these drugs might be of importance for migraine treatment. Eight normal male volunteers (not suffering from migraine) received 0.5 mg ergotamine and 1 mg dihydroergotamine i.......v. Cerebral blood flow was measured by the xenon-133 inhalation method and single-photon-emission computerized tomography before and after intravenous acetazolamide administration (1 g). Cerebral blood flow was measured before and 4 hours after ergotamine and dihydroergotamine administration. Strain......-gauge measurements of toe-arm systolic gradients were used to monitor the effect of the drug on leg arteries. Mean hemispheric and regional cerebral blood flow was unchanged after either drug (mean +/- SEM, ml/100 g/min): for ergotamine, 57 +/- 3 before and 57 +/- 3 at 4 hours; for dihydroergotamine, 54 +/- 2 before...

  11. Effect of non-Newtonian characteristics of blood on magnetic particle capture in occluded blood vessel

    Energy Technology Data Exchange (ETDEWEB)

    Bose, Sayan; Banerjee, Moloy, E-mail: moloy_kb@yahoo.com

    2015-01-15

    Magnetic nanoparticles drug carriers continue to attract considerable interest for drug targeting in the treatment of cancer and other pathological conditions. Magnetic carrier particles with surface-bound drug molecules are injected into the vascular system upstream from the desired target site, and are captured at the target site via a local applied magnetic field. Herein, a numerical investigation of steady magnetic drug targeting (MDT) using functionalized magnetic micro-spheres in partly occluded blood vessel having a 90° bent is presented considering the effects of non-Newtonian characteristics of blood. An Eulerian–Lagrangian technique is adopted to resolve the hemodynamic flow and the motion of the magnetic particles in the flow using ANSYS FLUENT. An implantable infinitely long cylindrical current carrying conductor is used to create the requisite magnetic field. Targeted transport of the magnetic particles in a partly occluded vessel differs distinctly from the same in a regular unblocked vessel. Parametric investigation is conducted and the influence of the insert configuration and its position from the central plane of the artery (z{sub offset}), particle size (d{sub p}) and its magnetic property (χ) and the magnitude of current (I) on the “capture efficiency” (CE) is reported. Analysis shows that there exists an optimum regime of operating parameters for which deposition of the drug carrying magnetic particles in a target zone on the partly occluded vessel wall can be maximized. The results provide useful design bases for in vitro set up for the investigation of MDT in stenosed blood vessels. - Highlights: • Two counter rotating vortices forces the fluid flow back through the more viscous region. • The existence of strong recirculation zone just downstream side of the occlusion. • Configuration 4 produces the better efficient MDT system. • Modified Casson model predicts the highest value of CE, whereas the generalized power law gives

  12. Effect of non-Newtonian characteristics of blood on magnetic particle capture in occluded blood vessel

    International Nuclear Information System (INIS)

    Magnetic nanoparticles drug carriers continue to attract considerable interest for drug targeting in the treatment of cancer and other pathological conditions. Magnetic carrier particles with surface-bound drug molecules are injected into the vascular system upstream from the desired target site, and are captured at the target site via a local applied magnetic field. Herein, a numerical investigation of steady magnetic drug targeting (MDT) using functionalized magnetic micro-spheres in partly occluded blood vessel having a 90° bent is presented considering the effects of non-Newtonian characteristics of blood. An Eulerian–Lagrangian technique is adopted to resolve the hemodynamic flow and the motion of the magnetic particles in the flow using ANSYS FLUENT. An implantable infinitely long cylindrical current carrying conductor is used to create the requisite magnetic field. Targeted transport of the magnetic particles in a partly occluded vessel differs distinctly from the same in a regular unblocked vessel. Parametric investigation is conducted and the influence of the insert configuration and its position from the central plane of the artery (zoffset), particle size (dp) and its magnetic property (χ) and the magnitude of current (I) on the “capture efficiency” (CE) is reported. Analysis shows that there exists an optimum regime of operating parameters for which deposition of the drug carrying magnetic particles in a target zone on the partly occluded vessel wall can be maximized. The results provide useful design bases for in vitro set up for the investigation of MDT in stenosed blood vessels. - Highlights: • Two counter rotating vortices forces the fluid flow back through the more viscous region. • The existence of strong recirculation zone just downstream side of the occlusion. • Configuration 4 produces the better efficient MDT system. • Modified Casson model predicts the highest value of CE, whereas the generalized power law gives the least

  13. Effect of white matter lesions on cerebral blood flow in asymptomatic individuals

    International Nuclear Information System (INIS)

    In 32 patients with asymptomatic white matter lesions (WMLs), we evaluated the age-related changes in the number of white matter lesions, cerebral blood flow (CBF), cerebrovascular resistance (CVR) and mean arterial blood pressure (MABP). CBF was measured with the intravenous 133Xe injection method. The number of WMLs in whole brain was measured by the magnetic resonance imaging. CBF decreased with advancing age (r=0.529; p<0.01), while the number of WMLs (r=0.39; p<0.05), CVR (r=0.464; p<0.01) and MABP (r=0.229; ns) increased with advancing age. There was a significantly negative correlation (r=-0.499; p<0.01) between CBF and the number of WMLs. While, CVR showed a positive correlation with the number of WMLs (r=0.468; p<0.01). Multivariate regression analysis with stepwise forward selection method indicated that the number of WMLs and age were independent and negative predictors for CBF, while other factors did not. CBF decreased with a concomitant rise in CVR. On the basis of the results listed above, we assumed that ischemic damage of the white matter and/or functional suppression of distant loci due to the primary tissue damage are the best explanation for CBF reduction in asymptomatic individuals with WMLs. High resolution CBF imaging as well as evaluation of structural alterations in cerebrovascular vessels should be required to further define the mechanisms. (author)

  14. A simple model of cerebral blood flow dependence on arterial blood pressure

    CERN Document Server

    Gersten, Alexander

    2011-01-01

    It is shown that the dependence of the cerebral blood flow (CBF) on mean arterial blood pressure (MABP) can be described with a simple model having the following assumptions. Below certain MABP (denoted as MABP1) there are no autoregulatory or feedback mechanisms influencing CBF. Between MABP1 and MABP2 (MABP at which breakthrough accurs) there is a linear (on MABP) dependent feedback with a sloap depending very much on the individual considered. The classical autoregulation model with a plateau in between MABP1 and MABP2 is a particular case of this model. The model describes well the experiments performed on dogs (Harper 1966), for which the individual feedback sloap parameter varied to great extent, indicating the importance of mesurments on individuals against averaged mesurments (or measurments on diffent individuals) which superficially support the classical autoregulation. New effect of decreased CBF, while increasing MABP, was observed.

  15. Cerebral Blood Flow and Autoregulation after Pediatric Traumatic Brain Injury

    OpenAIRE

    Udomphorn, Yuthana; Armstead, William M.; Vavilala, Monica S.

    2008-01-01

    Traumatic brain injury is a global health concern and is the leading cause of traumatic morbidity and mortality in children. Despite a lower overall mortality than in adult traumatic brain injury, the cost to society from the sequelae of pediatric traumatic brain injury is very high. Predictors of poor outcome after traumatic brain injury include altered systemic and cerebral physiology, including altered cerebral hemodynamics. Cerebral autoregulation is often impaired following traumatic bra...

  16. In vivo imaging of stepwise vessel occlusion in cerebral photothrombosis of mice by 19F MRI.

    Directory of Open Access Journals (Sweden)

    Gesa Weise

    Full Text Available BACKGROUND: (19F magnetic resonance imaging (MRI was recently introduced as a promising technique for in vivo cell tracking. In the present study we compared (19F MRI with iron-enhanced MRI in mice with photothrombosis (PT at 7 Tesla. PT represents a model of focal cerebral ischemia exhibiting acute vessel occlusion and delayed neuroinflammation. METHODS/PRINCIPAL FINDINGS: Perfluorocarbons (PFC or superparamagnetic iron oxide particles (SPIO were injected intravenously at different time points after photothrombotic infarction. While administration of PFC directly after PT induction led to a strong (19F signal throughout the entire lesion, two hours delayed application resulted in a rim-like (19F signal at the outer edge of the lesion. These findings closely resembled the distribution of signal loss on T2-weighted MRI seen after SPIO injection reflecting intravascular accumulation of iron particles trapped in vessel thrombi as confirmed histologically. By sequential administration of two chemically shifted PFC compounds 0 and 2 hours after illumination the different spatial distribution of the (19F markers (infarct core/rim could be visualized in the same animal. When PFC were applied at day 6 the fluorine marker was only detected after long acquisition times ex vivo. SPIO-enhanced MRI showed slight signal loss in vivo which was much more prominent ex vivo indicative for neuroinflammation at this late lesion stage. CONCLUSION: Our study shows that vessel occlusion can be followed in vivo by (19F and SPIO-enhanced high-field MRI while in vivo imaging of neuroinflammation remains challenging. The timing of contrast agent application was the major determinant of the underlying processes depicted by both imaging techniques. Importantly, sequential application of different PFC compounds allowed depiction of ongoing vessel occlusion from the core to the margin of the ischemic lesions in a single MRI measurement.

  17. Primo Vascular System Accompanying a Blood Vessel from Tumor Tissue and a Method to Distinguish It from the Blood or the Lymph System

    Directory of Open Access Journals (Sweden)

    Jaekwan Lim

    2013-01-01

    Full Text Available A primo vessel was observed in the abdominal cavity in the lung cancer mouse model, and its function as an extra metastatic path was observed. In this work, we found a primo vessel accompanying a blood vessel emanating from a tumor in the skin. We also presented simple and efficient criteria to distinguish a primo vessel from a blood or a lymph vessel and from a nerve. The criteria for using DAPI and Phalloidin will be useful in clinical situations to find and identify the primo vessels among the blood vessels, lymph vessels, or nerves in the tissue surrounding a tumor such as a melanoma or breast cancer.

  18. The influence of transcutaneous electrical neurostimulation (TENS) on human cerebral blood flow velocities

    OpenAIRE

    ter Laan, Mark; van Dijk, J. Marc C.; Elting, Jan-Willem J.; Fidler, Vaclav; Staal, Michiel J

    2010-01-01

    Background It has been shown that transcutaneous electrical neurostimulation (TENS) reduces sympathetic tone. Spinal cord stimulation (SCS) has proven qualities to improve coronary, peripheral, and cerebral blood circulation. Therefore, we postulate that TENS and SCS affect the autonomic nervous system in analogous ways. In this line of thought, cervical application of TENS might be a useful and simple adjunct in the treatment of cerebrovascular disease by improving cerebral blood flow. Exper...

  19. Dynamic alteration of regional cerebral blood flow during carotid compression and proof of reversibility

    OpenAIRE

    Asahi, Kouichi; Hori, M; Hamasaki, N; Sato, S.; Nakanishi, H; Kuwatsuru, R; Sasai, K; Aoki, S.

    2012-01-01

    Background It is difficult to non-invasively visualize changes in regional cerebral blood flow caused by manual compression of the carotid artery. Purpose To visualize dynamic changes in regional cerebral blood flow during and after manual compression of the carotid artery. Material and Methods Two healthy volunteers were recruited. Anatomic features and flow directions in the circle of Willis were evaluated with time-of-flight magnetic resonance angiography (MRA) and two-dimensional phase-co...

  20. Cerebral blood flow during delirium tremens and related clinical states studied with xenon-133 inhalation tomography

    International Nuclear Information System (INIS)

    The regional cerebral blood flow of 12 patients with severe alcohol withdrawal reactions (delirium tremens or impending delirium tremens) was measured during the acute state before treatment and after recovery. Greater cerebral blood flow was significantly correlated with visual hallucinations and agitation during the acute withdrawal reaction. The results suggest that delirium tremens and related clinical states represent a type of acute brain syndrome mainly characterized by CNS hyperexcitability

  1. Cerebral blood flow during delirium tremens and related clinical states studied with xenon-133 inhalation tomography

    Energy Technology Data Exchange (ETDEWEB)

    Hemmingsen, R.; Vorstrup, S.; Clemmesen, L.; Holm, S.; Tfelt-Hansen, P.; Sorensen, A.S.; Hansen, C.; Sommer, W.; Bolwig, T.G.

    1988-11-01

    The regional cerebral blood flow of 12 patients with severe alcohol withdrawal reactions (delirium tremens or impending delirium tremens) was measured during the acute state before treatment and after recovery. Greater cerebral blood flow was significantly correlated with visual hallucinations and agitation during the acute withdrawal reaction. The results suggest that delirium tremens and related clinical states represent a type of acute brain syndrome mainly characterized by CNS hyperexcitability.

  2. Intrauterine blood transfusion in immune hydrops fetalis, corrects middle cerebral artery Doppler velocimetry very quickly

    OpenAIRE

    Yalinkaya, Ahmet; Evsen, Mehmet Sıddık; Celik, Yusuf; Sak, Muhammet Erdal; Soydinc, Hatice Ender; Taner, Mehmet Zeki

    2012-01-01

    The aim of our study was to evaluate the middle cerebral artery velocimetry before and after intrauterine blood transfusion in immune hydrops fetalis. The current study was conducted in a tertiary research hospital, from February 2009 to January 2011. Nineteen intrauterine blood transfusions performed during the study period. The factors recorded were age of the mothers, gestational weeks, pre-transfusion fetal hematocrit and post-transfusion fetal hematocrit, and also middle cerebral artery ...

  3. Development of an accurate 3D blood vessel searching system using NIR light

    Science.gov (United States)

    Mizuno, Yoshifumi; Katayama, Tsutao; Nakamachi, Eiji

    2010-02-01

    Health monitoring system (HMS) and drug delivery system (DDS) require accurate puncture by needle for automatic blood sampling. In this study, we develop a miniature and high accurate automatic 3D blood vessel searching system. The size of detecting system is 40x25x10 mm. Our searching system use Near-Infrared (NIR) LEDs, CMOS camera modules and image processing units. We employ the stereo method for searching system to determine 3D blood vessel location. Blood vessel visualization system adopts hemoglobin's absorption characterization of NIR light. NIR LED is set behind the finger and it irradiates Near Infrared light for the finger. CMOS camera modules are set in front of the finger and it captures clear blood vessel images. Two dimensional location of the blood vessel is detected by luminance distribution of the image and its depth is calculated by the stereo method. 3D blood vessel location is automatically detected by our image processing system. To examine the accuracy of our detecting system, we carried out experiments using finger phantoms with blood vessel diameters, 0.5, 0.75, 1.0mm, at the depths, 0.5 ~ 2.0 mm, under the artificial tissue surface. Experimental results of depth obtained by our detecting system showed good agreements with given depths, and the availability of this system is confirmed.

  4. Estimation of vessel diameter and blood flow dynamics from laser speckle images

    DEFF Research Database (Denmark)

    Postnov, Dmitry D.; Tuchin, Valery V.; Sosnovtseva, Olga

    2016-01-01

    Laser speckle imaging is a rapidly developing method to study changes of blood velocity in the vascular networks. However, to assess blood flow and vascular responses it is crucial to measure vessel diameter in addition to blood velocity dynamics. We suggest an algorithm that allows for dynamical...... masking of a vessel position and measurements of it's diameter from laser speckle images. This approach demonstrates high reliability and stability....

  5. Human Blood-Vessel-Derived Stem Cells for Tissue Repair and Regeneration

    OpenAIRE

    Chien-Wen Chen; Mirko Corselli; Bruno Péault; Johnny Huard

    2012-01-01

    Multipotent stem/progenitor cells with similar developmental potentials have been independently identified from diverse human tissue/organ cultures. The increasing recognition of the vascular/perivascular origin of mesenchymal precursors suggested blood vessels being a systemic source of adult stem/progenitor cells. Our group and other laboratories recently isolated multiple stem/progenitor cell subsets from blood vessels of adult human tissues. Each of the three structural layers of blood ve...

  6. Estimation of vessel diameter and blood flow dynamics from laser speckle images

    Science.gov (United States)

    Postnov, Dmitry D.; Tuchin, Valery V.; Sosnovtseva, Olga

    2016-01-01

    Laser speckle imaging is a rapidly developing method to study changes of blood velocity in the vascular networks. However, to assess blood flow and vascular responses it is crucial to measure vessel diameter in addition to blood velocity dynamics. We suggest an algorithm that allows for dynamical masking of a vessel position and measurements of it’s diameter from laser speckle images. This approach demonstrates high reliability and stability.

  7. Mechanisms of recovery from aphasia: evidence from serial xenon 133 cerebral blood flow studies

    International Nuclear Information System (INIS)

    In 21 patients who suffered aphasia resulting from left hemisphere ischemic infarction, the xenon 133 inhalation cerebral blood flow technique was used to measure cerebral blood flow within 3 months and 5 to 12 months after stroke. In addition to baseline measurements, cerebral blood flow measurements were also carried out while the patients were performing purposeful listening. In patients with incomplete recovery of comprehension and left posterior temporal-inferior parietal lesions, greater cerebral blood flow occurred with listening in the right inferior frontal region in the late studies than in the early studies. In patients with nearly complete recovery of comprehension and without left posterior temporal-inferior parietal lesions, early listening studies showed diffuse right hemisphere increases in cerebral blood flow. Later listening studies in this latter patient group showed greater cerebral blood flow in the left posterior temporal-inferior parietal region. The study provides evidence for participation of the right hemisphere in language comprehension in recovering aphasics, and for later return of function in left hemisphere regions that may have been functionally impaired early during recovery

  8. Suitable image parameters and analytical method for quantitatively measuring cerebral blood flow volume with phase-contrast magnetic resonance imaging

    International Nuclear Information System (INIS)

    The aim of this study was to determine suitable image parameters and an analytical method for phase-contrast magnetic resonance imaging (PC-MRI) as a means of measuring cerebral blood flow volume. This was done by constructing an experimental model and applying the results to a clinical application. The experimental model was constructed from the aorta of a bull and circulating isotonic saline. The image parameters of PC-MRI (repetition time, flip angle, matrix, velocity rate encoding, and the use of square pixels) were studied with percent flow volume (the ratio of actual flow volume to measured flow volume). The most suitable image parameters for accurate blood flow measurement were as follows: repetition time, 50 msec; flip angle, 20 degrees; and a 512 x 256 matrix without square pixels. Furthermore, velocity rate encoding should be set ranging from the maximum flow velocity in the vessel to five times this value. The correction in measuring blood flow was done with the intensity of the region of interest established in the background. With these parameters for PC-MRI, percent flow volume was greater than 90%. Using the image parameters for PC-MRI and the analytical method described above, we evaluated cerebral blood flow volume in 12 patients with occlusive disease of the major cervical arteries. The results were compared with conventional xenon computed tomography. The values found with both methods showed good correlation. Thus, we concluded that PC-MRI was a noninvasive method for evaluating cerebral blood flow in patients with occlusive disease of the major cervical arteries. (author)

  9. Cerebral blood flow changes during sodium-lactate-induced panic attacks

    International Nuclear Information System (INIS)

    Dynamic single-photon emission computed axial tomography (CAT) with inhaled xenon-133 was used to measure regional cerebral blood flow in 10 drug-free patients with DSM-III-diagnosed panic disorder and in five normal control subjects. All subjects underwent regional cerebral blood flow studies while at rest or during normal saline infusion and during sodium lactate infusion. Six of the 10 patients and none of the control subjects experienced lactate-induced panic attacks. Lactate infusion markedly raised hemispheric blood flow levels in both control subjects and patients who did not panic. Patients who did panic experienced either a minimal increase or a decrease in hemispheric blood flow

  10. Development of Automatic 3D Blood Vessel Search and Automatic Blood Sampling System by Using Hybrid Stereo-Autofocus Method

    OpenAIRE

    Eiji Nakamachi; Yusuke Morita; Yoshifumi Mizuno

    2012-01-01

    We developed an accurate three-dimensional blood vessel search (3D BVS) system and an automatic blood sampling system. They were implemented into a point-of-care system designed for medical care, installed in a portable self-monitoring blood glucose (SMBG) device. The system solves problems of human error caused by complicated manual operations of conventional SMBG devices. We evaluated its accuracy of blood-vessel position detection. The 3D BVS system uses near-infrared (NIR) light imaging a...

  11. A computational model predicting disruption of blood vessel development.

    Directory of Open Access Journals (Sweden)

    Nicole Kleinstreuer

    2013-04-01

    Full Text Available Vascular development is a complex process regulated by dynamic biological networks that vary in topology and state across different tissues and developmental stages. Signals regulating de novo blood vessel formation (vasculogenesis and remodeling (angiogenesis come from a variety of biological pathways linked to endothelial cell (EC behavior, extracellular matrix (ECM remodeling and the local generation of chemokines and growth factors. Simulating these interactions at a systems level requires sufficient biological detail about the relevant molecular pathways and associated cellular behaviors, and tractable computational models that offset mathematical and biological complexity. Here, we describe a novel multicellular agent-based model of vasculogenesis using the CompuCell3D (http://www.compucell3d.org/ modeling environment supplemented with semi-automatic knowledgebase creation. The model incorporates vascular endothelial growth factor signals, pro- and anti-angiogenic inflammatory chemokine signals, and the plasminogen activating system of enzymes and proteases linked to ECM interactions, to simulate nascent EC organization, growth and remodeling. The model was shown to recapitulate stereotypical capillary plexus formation and structural emergence of non-coded cellular behaviors, such as a heterologous bridging phenomenon linking endothelial tip cells together during formation of polygonal endothelial cords. Molecular targets in the computational model were mapped to signatures of vascular disruption derived from in vitro chemical profiling using the EPA's ToxCast high-throughput screening (HTS dataset. Simulating the HTS data with the cell-agent based model of vascular development predicted adverse effects of a reference anti-angiogenic thalidomide analog, 5HPP-33, on in vitro angiogenesis with respect to both concentration-response and morphological consequences. These findings support the utility of cell agent-based models for simulating a

  12. Whole blood angiopoietin-1 and -2 levels discriminate cerebral and severe (non-cerebral malaria from uncomplicated malaria

    Directory of Open Access Journals (Sweden)

    Tangpukdee Noppadon

    2009-12-01

    Full Text Available Abstract Background Severe and cerebral malaria are associated with endothelial activation. Angiopoietin-1 (ANG-1 and angiopoietin-2 (ANG-2 are major regulators of endothelial activation and integrity. The aim of this study was to investigate the clinical utility of whole blood angiopoietin (ANG levels as biomarkers of disease severity in Plasmodium falciparum malaria. Methods The utility of whole blood ANG levels was examined in Thai patients to distinguish cerebral (CM; n = 87 and severe (non-cerebral malaria (SM; n = 36 from uncomplicated malaria (UM; n = 70. Comparative statistics are reported using a non-parametric univariate analysis (Kruskal-Wallis test or Chi-squared test, as appropriate. Multivariate binary logistic regression was used to examine differences in whole blood protein levels between groups (UM, SM, CM, adjusting for differences due to ethnicity, age, parasitaemia and sex. Receiver operating characteristic curve analysis was used to assess the diagnostic accuracy of the ANGs in their ability to distinguish between UM, SM and CM. Cumulative organ injury scores were obtained for patients with severe disease based on the presence of acute renal failure, jaundice, severe anaemia, circulatory collapse or coma. Results ANG-1 and ANG-2 were readily detectable in whole blood. Compared to UM there were significant decreases in ANG-1 (p Conclusions These results suggest that whole blood ANG-1/2 levels are promising clinically informative biomarkers of disease severity in malarial syndromes.

  13. Reduction in cerebral blood flow volume in infants complicated with hypoxic ischemic encephalopathy resulting in cerebral palsy.

    Science.gov (United States)

    Fukuda, Sumio; Mizuno, Keisuke; Kawai, Satomi; Kakita, Hiroki; Goto, Tatenobu; Hussein, Mohamed Hamed; Daoud, Ghada A; Ito, Tetsuya; Kato, Ineko; Suzuki, Satoshi; Togari, Hajime

    2008-04-01

    Hypoxic ischemic brain can result in cerebral palsy, mental retardation, and learning disabilities in surviving children. The purpose of this study was to elucidate the cerebral blood flow volume in infants complicated with brain damage after the birth. Nine term infants with hypoxic ischemic encephalopathy and 41 normal term infants were studied. Four infants with HIE suffered from CP or mental retardation, and the other five infants exhibited normal neurodevelopment. The mean blood flow velocity and diameter of the internal carotid artery and the vertebral artery were measured for 28 days. The intravascular flow volume was determined by calculating the flow velocity and the cross-sectional area. The ejection fraction and cardiac output were obtained, and the mean blood pressures were recorded. The summed flow volumes in both the ICA and VA, and the total CBFV increased after the birth in both the normal infants and the infants diagnosed with HIE with no disability complications. The total blood flow volume was significantly lower in infants with HIE and CP than in normal infants on days 0, 2, 5, 7, 10, 21, and 28, and significantly lower in infants with HIE and CP than in normal infants with HIE on days 2, 4, and 7. The ejection fraction was significantly lower in infants with HIE than in normal infants only on day 0. Our results suggest that the total cerebral blood supply is decreased in infants with HIE in those complicated with brain damage. PMID:17950550

  14. Cerebral cortical neurons with activity linked to central neurogenic spontaneous and evoked elevations in cerebral blood flow

    Science.gov (United States)

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

    1996-01-01

    We recorded neurons in rat cerebral cortex with activity relating to the neurogenic elevations in regional cerebral blood flow (rCBF) coupled to stereotyped bursts of EEG activity, burst-cerebrovascular wave complexes, appearing spontaneously or evoked by electrical stimulation of rostral ventrolateral medulla (RVL) or fastigial nucleus (FN). Of 333 spontaneously active neurons only 15 (5%), in layers 5-6, consistently (P neurons in deep cortical laminae whose activity correlates with neurogenic elevations of rCBF. These neurons may function to transduce afferent neuronal signals into vasodilation.

  15. 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).

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

    International Nuclear Information System (INIS)

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

  17. Computational Fluid Dynamics Analysis of Pulsatile Blood Flow Behavior in Modelled Stenosed Vessels with Different Severities

    OpenAIRE

    Mohsen Mehrabi; Saeed Setayeshi

    2012-01-01

    This study focuses on the behavior of blood flow in the stenosed vessels. Blood is modelled as an incompressible non-Newtonian fluid which is based on the power law viscosity model. A numerical technique based on the finite difference method is developed to simulate the blood flow taking into account the transient periodic behaviour of the blood flow in cardiac cycles. Also, pulsatile blood flow in the stenosed vessel is based on the Womersley model, and fluid flow in the lumen region is gove...

  18. Cerebral blood volume, genotype and chemosensitivity in oligodendroglial tumours

    Energy Technology Data Exchange (ETDEWEB)

    Jenkinson, Michael D. [Walton Centre for Neurology and Neurosurgery, Department of Neurosurgery, Liverpool (United Kingdom); University of Liverpool, Division of Neuroscience, Liverpool (United Kingdom); Smith, Trevor S. [Walton Centre for Neurology and Neurosurgery, Department of Neuroradiology, Liverpool (United Kingdom); Joyce, Kathy A.; Fildes, Diane [JK Douglas Laboratories, Clatterbridge Cancer Research Trust, Wirral (United Kingdom); Broome, John [Walton Centre for Neurology and Neurosurgery, Department of Neuropathology, Liverpool (United Kingdom); Plessis, Daniel G. du [University of Liverpool, Division of Neuroscience, Liverpool (United Kingdom); Haylock, Brian; Husband, David J. [Clatterbridge Hospital, Clatterbridge Centre for Oncology, Neuro-Oncology, Wirral (United Kingdom); Warnke, Peter C. [Leibniz Institute for Neurobiology, Magdeburg (Germany); Walker, Carol [University of Liverpool, Division of Neuroscience, Liverpool (United Kingdom); JK Douglas Laboratories, Clatterbridge Cancer Research Trust, Wirral (United Kingdom)

    2006-10-15

    The biological factors responsible for differential chemoresponsiveness in oligodendroglial tumours with or without the -1p/-19q genotype are unknown, but tumour vascularity may contribute. We aimed to determine whether dynamic susceptibility contrast (DSC) magnetic resonance imaging (MRI) could distinguish molecular subtypes of oligodendroglial tumour, and examined the relationship between relative cerebral blood volume (rCBV) and outcome following procarbazine, lomustine and vincristine (PCV) chemotherapy. Pretherapy rCBV was calculated and inter- and intraobserver variability assessed. Allelic imbalance in 1p36, 19q13, 17p13, 10p12-15, and 10q22-26 and p53 mutation (exons 5-8) were determined. rCBV was compared with genotype and clinicopathological characteristics (n=37) and outcome following PCV chemotherapy (n=33). 1p/19q loss was seen in 6/9 grade II oligodendrogliomas, 6/14 grade II oligoastrocytomas, 4/4 grade III oligodendrogliomas, and 3/10 grade III oligoastrocytomas. rCBV measurements had good inter- and intraobserver variability, but did not distinguish histology subtype or grade. Tumours with 1p/19q loss had higher rCBV values (Student's t-test P=0.001). Receiver operating characteristic analysis revealed a cut-off of 1.59 for identifying genotype (sensitivity 92%, specificity 76%). Tumours with high and low rCBV showed response to chemotherapy. The -1p/-19q genotype, but not rCBV, was strongly associated with response, progression-free and overall survival following PCV chemotherapy. Tumours with high rCBV and intact 1p/19q were associated with shorter progression-free and overall patient survival than those with intact 1p/19q and low rCBV or high rCBV and 1p/19q loss. (orig.)

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

    Science.gov (United States)

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

    2012-02-01

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

  20. Do Haematophagous Bugs Assess Skin Surface Temperature to Detect Blood Vessels?

    OpenAIRE

    Raquel A Ferreira; Lazzari, Claudio R.; Marcelo G. Lorenzo; Pereira, Marcos H

    2007-01-01

    Background It is known that some blood-sucking insects have the ability to reach vessels under the host skin with their mouthparts to feed blood from inside them. However, the process by which they locate these vessels remains largely unknown. Less than 5% of the skin is occupied by blood vessels and thus, it is not likely that insects rely on a “random search strategy”, since it would increase the probability of being killed by their hosts. Indeed, heterogeneities along the skin surface migh...

  1. Semiquantifying regional cerebral blood flow by dynamic CT scanning

    International Nuclear Information System (INIS)

    The study was undertaken to evaluate the semi-quantitative significance of the absolute value obtained by calculating the regional cerebral blood flow index (rCBFI) from dynamic CT in comparison with SPECT. rCBFI was calculated from mean transit time (MTT) and blood capacity index (BCI) obtained by rapidly infusing 50 ml of Omnipurk into the elbow vein by the use of Hitachi's W-600. [rCBFI=BCI/MTT unit/sec (U/S)] measurment of the rCBF by SPECT was made according to the semi-quantitative method by Matsuda et al. by the use of SHIMADZU's improved type HEADTOME SET-050 with rapid infusion of 123I-IMP in 3.5 m Ci from the elbow vein. Patients in whom no abnormality was observed in the cardiopulmonary function were enrolled as subjects. The rCBFI in each intracranial site was calculated from dynamic CT in 10 normal adults (aged 35-60, averaging 46.7) as subjects and compared with the rCBF obtained from SPECT in the same cases and same site. Comparative investigation was made similarly between rCBFI and rCBF regarding 10 patients with tracranial diseases (age 29-65, averaging 51.2). The mean rCBFIs in the normal adults obtained from dynamic CT were 1.15±0.18 U/S in the frontal lobar cortex, 1.28±0.19 U/S in the temporal lobar cortex, 1.43±0.1 U/S in the occipital lobar cortex, 1.27±0.2 U/S in the basal ganglia region and 0.43±0.1 U/S in the white matter. On the other hand, the mean rCBFs by SPECT were 47.36±3.93 ml/100 g/min, 55.19±2.22 ml/100 g/min, 61.92±5.42 ml/100 g/min, 54.38±3.51 ml/100 g/min and 38.68±6.18 ml/100 g/min, respectively. Positive correlation was observed between rCBFIs and rCBFs of 10 normal adults and 10 patients with intracranial disease, totalling 20 cases (r=0.79, P<0.005). The rCBFI by dynamic CT has a correlation with the rCBF by SPECT, suggesting the possibility of its evaluation as an absolute value, though semi-quantitatively. (author)

  2. Blood gases and energy metabolites in mouse blood before and after cerebral ischemia: the effects of anesthetics.

    Science.gov (United States)

    Schwarzkopf, Tina M; Horn, Tobias; Lang, Dorothee; Klein, Jochen

    2013-01-01

    The levels of blood gases and energy metabolites strongly influence the outcome of animal experiments, for example in experimental stroke research. While mice have become prominent animal models for cerebral ischemia, little information is available on the effects of anesthetic drugs on blood parameters such as blood gases, glucose and lactate in this species. In this work, we collected arterial and venous blood samples from female CD-1 mice before and after cerebral ischemia induced by middle cerebral artery occlusion (MCAO), and we tested the influence of different anesthetic drugs. We found that all of the injectable anesthetics tested (ketamine/xylazine, chloral hydrate, propofol and pentobarbital) caused a decrease in blood pH and partial pressure of oxygen (pO2) and an increase of partial pressure of carbon dioxide (pCO2), indicating respiratory depression. This was not observed with inhalable anesthetics such as isoflurane, sevoflurane and halothane. Significant and up to two-fold increases of blood glucose concentration were observed under isoflurane, halothane, ketamine/xylazine, chloral hydrate, and propofol anesthesia. Lactate concentration rose significantly by 2-3-fold during inhalation of isoflurane and halothane treatment, but decreased by more than 50% after administration of pentobarbital. Permanent cerebral ischemia induced respiratory acidosis (low pH and pO2, high pCO2) which was most prominent after 24 h. Postsurgical treatment with Ringer-lactate solution (1 mL, intraperitoneal) caused a recovery of blood gases to basal levels after 24 h. Use of isoflurane for surgery caused a minor increase of blood glucose concentrations after one hour, but a strong increase of blood lactate. In contrast, anesthesia with pentobarbital did not affect glucose concentration but strongly reduced blood lactate concentrations one hour after surgery. All values recovered at three hours after MCAO. In conclusion, anesthetic drugs have a strong influence on murine

  3. Loop Modeling Forward and Feedback Analysis in Cerebral Arteriovenous Malformation

    OpenAIRE

    Y. Kiran Kumar; Shashi.B.Mehta; Manjunath Ramachandra

    2013-01-01

    Cerebral Arteriovenous Malformation (CAVM) hemodynamic in disease condition results changes in the flow and pressure level in blood vessels. Cerebral Arteriovenous Malformation (CAVM) is an abnormal shunting of vessels between arteries and veins. It is one of the common Brain disorder. In general, the blood flows of cerebral region are from arteries to veins through capillary bed. This paper is focus on the creation of a new electrical model for spiral loop structures that will simulate the p...

  4. Laser Doppler flowmetry is valid for measurement of cerebral blood flow autoregulation lower limit in rats

    DEFF Research Database (Denmark)

    Tonnesen, Jan; Pryds, Anders; Larsen, Erik Hviid;

    2005-01-01

    Laser Doppler flowmetry (LDF) is a recent technique that is increasingly being used to monitor relative changes in cerebral blood flow whereas the intra-arterial 133xenon injection technique is a well-established method for repeated absolute measurements of cerebral blood flow. The aim of this st......Laser Doppler flowmetry (LDF) is a recent technique that is increasingly being used to monitor relative changes in cerebral blood flow whereas the intra-arterial 133xenon injection technique is a well-established method for repeated absolute measurements of cerebral blood flow. The aim...... in similar results. We conclude that even though LDF overestimated CBF during haemorrhagic shock caused by controlled haemorrhage, the lower limit autoregulation was correctly identified. The laser Doppler technique provides a reliable method for detection of a wide range of cerebral blood flow changes under...... CO2 challenge. Haemodilution influences the two methods differently causing relative overestimation of blood flow by the laser Doppler technique compared to the 133xenon method....

  5. Emesis, radiation exposure, and local cerebral blood flow in the ferret

    Energy Technology Data Exchange (ETDEWEB)

    Tuor, U.I.; Kondysar, M.H.; Harding, R.K.

    1988-06-01

    We examined the sensitivity of the ferret to emetic stimuli and the effect of radiation exposure near the time of emesis on local cerebral blood flow. Ferrets vomited following the administration of either apomorphine (approx 45% of the ferrets tested) or peptide YY (approx 36% of those tested). Exposure to radiation was a very potent emetic stimulus, but vomiting could be prevented by restraint of the hindquarters of the ferret. Local cerebral blood flow was measured using a quantitative autoradiographic technique and with the exception of several regions in the telencephalon and cerebellum, local cerebral blood flow in the ferret was similar to that in the rat. In animals with whole-body exposure to moderate levels of radiation (4 Gy of /sup 137/Cs), mean arterial blood pressure was similar to that in the control group. However, 15-25 min following irradiation there was a general reduction of local cerebral blood flow ranging from 7 to 33% of that in control animals. These cerebral blood flow changes likely correspond to a reduced activation of the central nervous system.

  6. Partial pharmacologic blockade shows sympathetic connection between blood pressure and cerebral blood flow velocity fluctuations.

    Science.gov (United States)

    Hilz, Max J; Wang, Ruihao; Marthol, Harald; Liu, Mao; Tillmann, Alexandra; Riss, Stephan; Hauck, Paulina; Hösl, Katharina M; Wasmeier, Gerald; Stemper, Brigitte; Köhrmann, Martin

    2016-06-15

    Cerebral autoregulation (CA) dampens transfer of blood pressure (BP)-fluctuations onto cerebral blood flow velocity (CBFV). Thus, CBFV-oscillations precede BP-oscillations. The phase angle (PA) between sympathetically mediated low-frequency (LF: 0.03-0.15Hz) BP- and CBFV-oscillations is a measure of CA quality. To evaluate whether PA depends on sympathetic modulation, we assessed PA-changes upon sympathetic stimulation with and without pharmacologic sympathetic blockade. In 10 healthy, young men, we monitored mean BP and CBFV before and during 120-second cold pressor stimulation (CPS) of one foot (0°C ice-water). We calculated mean values, standard deviations and sympathetic LF-powers of all signals, and PAs between LF-BP- and LF-CBFV-oscillations. We repeated measurements after ingestion of the adrenoceptor-blocker carvedilol (25mg). We compared parameters before and during CPS, without and after carvedilol (analysis of variance, post-hoc t-tests, significance: p<0.05). Without carvedilol, CPS increased BP, CBFV, BP-LF- and CBFV-LF-powers, and shortened PA. Carvedilol decreased resting BP, CBFV, BP-LF- and CBFV-LF-powers, while PAs remained unchanged. During CPS, BPs, CBFVs, BP-LF- and CBFV-LF-powers were lower, while PAs were longer with than without carvedilol. With carvedilol, CPS no longer shortened resting PA. Sympathetic activation shortens PA. Partial adrenoceptor blockade abolishes this PA-shortening. Thus, PA-measurements provide a subtle marker of sympathetic influences on CA and might refine CA evaluation. PMID:27206903

  7. New angiographic measurement tool for analysis of small cerebral vessels: application to a subarachnoid haemorrhage model in the rat

    International Nuclear Information System (INIS)

    Exact quantification of vasospasm by angiography is known to be difficult especially in small vessels. The purpose of the study was to develop a new method for computerized analysis of small arteries and to demonstrate feasibility on cerebral angiographies of rats acquired on a clinical angiography unit. A new software tool analysing grey values and subtracting background noise was validated on a vessel model. It was tested in practice in animals with subarachnoid haemorrhage (SAH). A total of 28 rats were divided into four groups: SAH untreated, SAH treated with local calcium antagonist, SAH treated with placebo, and sham-operated. The diameters of segments of the internal carotid, caudal cerebral, middle cerebral, rostral cerebral and the stapedial arteries were measured and compared to direct measurements of the diameters on magnified images. There was a direct correlation between the cross-sectional area of vessels measured in a phantom and the measurements acquired using the new image analysis method. The spread of repeated measurements with the new software was small compared to the spread of direct measurements of vessel diameters on magnified images. Application of the measurement tool to experimental SAH in rats showed a statistically significant reduction of vasospasm in the SAH groups treated with nimodipine-releasing pellets in comparison to all the other groups combined. The presented computerized method for analysis of small intracranial vessels is a new method allowing precise relative measurements. Nimodipine-releasing subarachnoidal pellets reduce vasospasm, but further testing with larger numbers is necessary. The tool can be applied to human angiography without modification and offers the promise of substantial progress in the diagnosis of vasospasm after SAH. (orig.)

  8. Blood vessel growth blocker may treat AIDS-related Kaposi’s sarcoma

    Science.gov (United States)

    Patients with an AIDS-associated cancer, Kaposi's sarcoma (KS), showed improvement after receiving the combination of bevacizumab, a cancer drug that blocks the growth of new blood vessels, and highly active antiretroviral therapy (HAART).

  9. Aerobic fitness is associated with greater hippocampal cerebral blood flow in children.

    Science.gov (United States)

    Chaddock-Heyman, Laura; Erickson, Kirk I; Chappell, Michael A; Johnson, Curtis L; Kienzler, Caitlin; Knecht, Anya; Drollette, Eric S; Raine, Lauren B; Scudder, Mark R; Kao, Shih-Chun; Hillman, Charles H; Kramer, Arthur F

    2016-08-01

    The present study is the first to investigate whether cerebral blood flow in the hippocampus relates to aerobic fitness in children. In particular, we used arterial spin labeling (ASL) perfusion MRI to provide a quantitative measure of blood flow in the hippocampus in 73 7- to 9-year-old preadolescent children. Indeed, aerobic fitness was found to relate to greater perfusion in the hippocampus, independent of age, sex, and hippocampal volume. Such results suggest improved microcirculation and cerebral vasculature in preadolescent children with higher levels of aerobic fitness. Further, aerobic fitness may influence how the brain regulates its metabolic demands via blood flow in a region of the brain important for learning and memory. To add specificity to the relationship of fitness to the hippocampus, we demonstrate no significant association between aerobic fitness and cerebral blood flow in the brainstem. Our results reinforce the importance of aerobic fitness during a critical period of child development. PMID:27419884

  10. A study of the cerebral blood flow pattern and cognitive deficit in Parkinson's disease

    International Nuclear Information System (INIS)

    Cerebral blood flow pattern in Parkinson's disease was examined by 123I-IMP SPECT to determine whether the deficit in cognitive function is reflected in it. The patient group with Parkinson's disease showed deterioration in intelligence (Minimental state examination, Raven's Colored Progressive Matrices) and frontal lobe test (the Wisconsin Card Sorting Test). Though the uptake ratio of prefrontal area/occipital area in 123I-IMP SPECT study varied widely in the Parkinson's disease group compared to the normal control group, there was no significant difference in the mean. Selective depletion of frontal lobe blood flow was not confirmed in this study. There was no correlation between cerebral blood flow pattern and cognitive functions including frontal lobe function and intelligence. We concluded that the deficit in cognitive function was not reflected in the cerebral blood flow pattern in Parkinson's disease. (author)

  11. A new imaging method of cerebral blood flow by 133Xe inhalation: application for studying naloxone in cerebral ischemia

    International Nuclear Information System (INIS)

    A calculation and dynamic imaging method of cerebral blood flow (CBF) based on gamma camera images after 133-Xenon inhalation is proposed. The method consists in the deconvolution by approximation of the time sequence of brain scans by the values for the arterial concentration. Computation is limited to the first 2 minutes of wash-out. Results are compared to those obtained with the Obrist method and with Fourier-transform deconvolution. In 28 patients data obtained with the 3 methods were found to show good agreement (r=0.93). The method was used to study the effects of low-dose Naloxone on cerebral blood flow in ischemic patients and evidence of some regional hemodynamic action was obtained. But these changes apparently do not correspond with the definite, though transient clinical improvement seen in 5 patients. (Author)

  12. ENHANCED ABSORPTION OF MILLIMETER WAVE ENERGY IN MURINE SUBCUTANEOUS BLOOD VESSELS

    OpenAIRE

    Alekseev, Stanislav I.; Ziskin, Marvin C.

    2011-01-01

    The aim of the present study was to determine millimeter wave (MMW) absorption by blood vessels traversing the subcutaneous fat layer of murine skin. Most calculations were performed using the finite-difference time-domain (FDTD) technique. We used two types of models: (1) a rectangular block of multilayer tissue with blood vessels traversing the fat layer and (2) cylindrical models with circular and elliptical cross sections simulating the real geometry of murine limbs. We found that the spe...

  13. Assessing the quality of angiographic display of brain blood vessels aneurysms compared to intraoperative state

    OpenAIRE

    Nikolić Igor M.; Tasić Goran M.; Jovanović Vladimir T.; Repac Nikola R.; Janićijević Aleksandar M.; Šćepanović Vuk D.; Nestorović Branislav D.

    2013-01-01

    Background/Aim. Aneurysms in brain blood vessels are expanding bags composed of a neck, body and fundus. Clear visibility of the neck, the position of the aneurysm and surrounding structures are necessary for a proper choice of methods for excluding the aneurysm from the circulation. The aim of this study was to evaluate the reliability of spatial reconstruction of blood vessels of the brain based on the original software for 3D reconstruction of the equipment manufacturer and a persona...

  14. Detection of retinal blood vessel changes in multiple sclerosis with optical coherence tomography

    OpenAIRE

    Bhaduri, Basanta; Nolan, Ryan M.; Shelton, Ryan L.; Pilutti, Lara A.; Motl, Robert W.; Moss, Heather E.; Pula, John H.; Boppart, Stephen A.

    2016-01-01

    Although retinal vasculitis is common in multiple sclerosis (MS), it is not known if MS is associated with quantitative abnormalities in retinal blood vessels (BVs). Optical coherence tomography (OCT) is suitable for examining the integrity of the anterior visual pathways in MS. In this paper we have compared the size and number of retinal blood vessels in patients with MS, with and without a history of optic neuritis (ON), and control subjects from the cross-sectional retinal images from OCT...

  15. Visualisation of blood and lymphatic vessels with increasing exposure time of the detector

    Energy Technology Data Exchange (ETDEWEB)

    Kalchenko, V V; Kuznetsov, Yu L; Meglinski, I V

    2013-07-31

    We describe the laser speckle contrast method for simultaneous noninvasive imaging of blood and lymphatic vessels of living organisms, based on increasing detector exposure time. In contrast to standard methods of fluorescent angiography, this technique of vascular bed imaging and lymphatic and blood vessel demarcation does not employ toxic fluorescent markers. The method is particularly promising with respect to the physiology of the cardiovascular system under in vivo conditions. (laser applications in biology and medicine)

  16. 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, a...... ventilation strategy guided by jugular bulb oximetry and/or repeated CBF measurements may be more optimal in terms of cerebral oxygenation than a strategy aiming at identical levels of P(a)CO(2) for all patients....

  17. Changes in regional cerebral blood flow during auditory cognitive tasks

    International Nuclear Information System (INIS)

    In order to investigate the relation between auditory cognitive function and regional brain activation, we measured the changes in the regional cerebral blood flow (CBF) using positron emission tomography (PET) during the 'odd-ball' paradigm in ten normal healthy volunteers. The subjects underwent 3 tasks, twice for each, while the evoked potential was recorded. In these tasks, the auditory stimulus was a series of pure tones delivered every 1.5 sec binaurally at 75 dB from the earphones. Task A: the stimulus was a series of tones with 1000 Hz only, and the subject was instructed to only hear. Task B: the stimulus was a series of tones with 1000 Hz only, and the subject was instructed to push the button on detecting a tone. Task C: the stimulus was a series of pure tones delivered every 1.5 sec binaurally at 75 dB with a frequency of 1000 Hz (non-target) in 80% and 2000 Hz (target) in 20% at random, and the subject was instructed to push the button on detecting a target tone. The event related potential (P300) was observed in task C (Pz: 334.3±19.6 msec). At each task, the CBF was measured using PET with i.v. injection of 1.5 GBq of O-15 water. The changes in CBF associated with auditory cognition was evaluated by the difference between the CBF images in task C and B. Localized increase was observed in the anterior cingulate cortex (in all subjects), the bilateral associate auditory cortex, the prefrontal cortex and the parietal cortex. The latter three areas had a large individual variation in the location of foci. These results suggested the role of those cortical areas in auditory cognition. The anterior cingulate was most activated (15.0±2.24% of global CBF). This region was not activated in the condition of task B minus task A. The anterior cingulate is a part of Papez's circuit that is related to memory and other higher cortical function. These results suggested that this area may play an important role in cognition as well as in attention. (author)

  18. Regional cerebral blood flow changes in chronic polidrug abusers

    International Nuclear Information System (INIS)

    Chronic exposure to cocaine and other drugs are in clear association with a variety of medical complications, involving many organ systems. The Central Nervous System (CNS) is particularly sensitive to such exposures: permanent behavioral, psychiatric and neurological complications are common in this group of patients. Regional cerebral blood perfusion (rCBF) analysis has been used to study these conditions with PET and SPECT for a long time. According to the literature, it is clear that drug exposure (particularly cocaine) does produce significant changes over rCBF, nevertheless the vast majority of SPECT and some PET studies are difficult to reproduce because they were analyzed using subjective (visual) and/or ROI's to address the changes. Aim: To study the pattern of rCBF change of chronic cocaine and other drugs (polidrug) users/abusers population using brain SPECT and SPM (Statistical Parametric Mapping). Material and Methods: From a population of 163 addicted patients, 55 chronic cocaine and other drugs users/abuser were selected. A pre-treatment brain SPECT under basal conditions was performed in all of them. 99mTc-ECD was used as rCBF tracer and SPM (Statistical Parametric Mapping) as a framework to address statistically significant rCBF variations of change. The whole group was compared with a population of normal patients (both sexes, aged between 20 and 40 y.o., no history of trauma, drug exposure, neurological or psychiatric disorders). Results: Significant areas of reduced (hypoperfusion) and increased (hyperperfusion) rCBF were identified in the patients group. The hypoperfusion areas involve mainly the left insula region and the surrounding frontal and temporal lobe and a smaller area in the anterior and inferior portion of the right frontal lobe. The increased perfusion areas were identified at the left thalamus and the right fronto-parietal cortical region. Conclusion: Our results suggest that chronic cocaine exposure produce activation/damage to

  19. Association between Serum Alkaline Phosphatase Level and Cerebral Small Vessel Disease.

    Directory of Open Access Journals (Sweden)

    Han-Bin Lee

    Full Text Available Serum alkaline phosphatase (ALP is a marker of vascular calcification. A high serum ALP level is associated with an increase in cardiovascular events, and predicts poor functional outcome in patients with stroke. We investigated whether serum ALP was associated with cerebral small vessel disease (cSVD and large cerebral artery stenosis (LCAS.We evaluated vascular risk factors, brain magnetic resonance images (MRIs, and MR angiograms from 1,011 neurologically healthy participants. The presence of silent lacunar infarction (SLI and moderate-to-severe cerebral white matter hyperintensities (MS-cWMH were evaluated as indices of cSVD on brain MRIs. Findings of extracranial arterial stenosis (ECAS or intracranial arterial stenosis (ICAS were considered to be indices of LCAS on MR angiograms.Subjects with SLI (odds ratio [OR]: 2.09; 95% confidence interval [CI]: 1.27-3.42; p = 0.004 and MS-cWMH (OR: 1.48; 95% CI; 1.03-2.13, p = 0.036 were significantly more likely to have ALP levels in the third tertile (ALP ≥ 195 IU/L than the first tertile (ALP ≤ 155 IU/L, after adjusting for cardiovascular risk factors. The mean serum ALP level was significantly higher in patients with SLI or MS-cWMH compared to patients without those findings. After adjustment for confounding factors, the multivariate model found that the statistical significance of serum ALP remained when the presence of SLI (OR: 1.05 per 10 IU/L increase in ALP; 95% CI: 1.02-1.08; p = 0.003 or MS-cWMH (OR: 1.03 per 10 IU/L increase in ALP; 95% CI: 1.00-1.06; p = 0.025 were added to the model. There were no differences in the proportions of patients with LCAS, ICAS, and ECAS across the serum ALP tertiles.Our study of neurologically healthy participants found a positive association between serum ALP level and indicators of cSVD, but no association between serum ALP level and the indicators of LCAS.

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

    DEFF Research Database (Denmark)

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

    2016-01-01

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

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

    International Nuclear Information System (INIS)

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

  2. Problems in cerebral blood flow calculation using xenon-133 in patients with pulmonary diseases

    International Nuclear Information System (INIS)

    We used the end-tidal concentration of xenon-133 (air curve) to estimate the profile of its arterial concentration in calculating cerebral blood flow. We examined the effects of pulmonary disease and artificial ventilation on the air curve and the calculated cerebral blood flow. We studied the relation between arterial and end-tidal xenon activities in 19 subjects, of whom 15 had pulmonary dysfunction. The t 1/2 of the declining phases of the arterial and air curves were used to express their shapes. The mean +/- SD reference t 1/2 from 15 normal volunteers was 26.8 +/- 8.4 seconds. The mean +/- SD t 1/2 s of the air and arterial curves from the 15 patients with pulmonary dysfunction were 10.4 +/- 2.9 and 33.8 +/- 10.9 seconds. The degree of pulmonary dysfunction (expressed as the pulmonary shunt percentage) correlated with distortion of the air curve. Substituting the arterial for the air curve, mean calculated cerebral blood flow (as the initial slope index) increased from 40 to 61 for the 12 patients with chronic obstructive pulmonary disease. The degree of underestimation of cerebral blood flow using the air curve correlated with the pulmonary shunt percentage. Our work confirms the problems of estimating cerebral blood flow in subjects with pulmonary dysfunction

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

    OpenAIRE

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

    1999-01-01

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

  4. Growth and Remodeling in Blood Vessels Studied In Vivo With Fractal Analysis

    Science.gov (United States)

    Parsons-Wingerter, Patricia A.

    2003-01-01

    Every cell in the human body must reside in close proximity to a blood vessel (within approximately 200 mm) because blood vessels provide the oxygen, metabolite, and fluid exchanges required for cellular existence. The growth and remodeling of blood vessels are required to support the normal physiology of embryonic development, reproductive biology, wound healing and adaptive remodeling to exercise, as well as abnormal tissue change in diseases such as cancer, diabetes, and coronary heart disease. Cardiovascular and hemodynamic (blood flow dynamics) alterations experienced by astronauts during long-term spaceflight, including orthostatic intolerance, fluid shifts in the body, and reduced numbers of red (erythrocyte) and white (immune) blood cells, are identified as risk factors of very high priority in the NASA task force report on risk reduction for human spaceflight, the "Critical Path Roadmap."

  5. Tomographic non-invasive measurements of regional cerebral blood flow

    International Nuclear Information System (INIS)

    The measurement of the regional cerebral bloodflow by means of the dynamic single-photon-emissioncomputed tomography is a method of examination which is completely free of risk for the patient, causes no inconvenience and can be repeated whenever it seems necessary. This method gives a quantitative explanation for the distribution of the effective cerebral perfusion and can only be substituted by the very complicated positron-emission-computed tomography. As well as the exact assessment of the hemodynamic relevance of cerebral vascular disease, this method enables us to prove whether or not in various types of psychiatric disorders an interference in the regional perfusion exists. This method can also contribute to the clarification of pathogenic mechanisms, as well as to the nosological classification of specific psychopathological conditions. (orig.)

  6. Stroke severity and incidence of acute large vessel occlusions in patients with hyper-acute cerebral ischemia

    DEFF Research Database (Denmark)

    Hansen, Christine Kraup; Christensen, Anders Fogh; Ovesen, C;

    2015-01-01

    vessel occlusions and describe the relations to the National Institutes of Health Stroke Scale (NIHSS), lesion site and time from symptom onset in unselected consecutive patients with hyper-acute cerebral ischemia. METHODS: A prospective single hospital registry was based on consecutive unselected...... occlusions and the effect of time after symptom onset was assessed. RESULTS: Six hundred thirty-seven patients, with admission NIHSS: 1-42, were included; 183 patients presented with acute vessel occlusions (28.7%) in 15 different combinations of occlusions. The best NIHSS-cut-off for detecting any occlusion...

  7. Cerebral blood flow determination within the first 8 hours of cerebral infarction using stable xenon-enhanced computed tomography

    International Nuclear Information System (INIS)

    Cerebral blood flow mapping with stable xenon-enhanced computed tomography (Xe/CT) was performed in conjunction with conventional computed tomography (CT) within the first 8 hours after the onset of symptoms in seven patients with cerebral infarction. Six patients had hemispheric infarctions, and one had a progressive brainstem infarction. Three patients with very low (less than 10 ml/100 g/min) blood flow in an anatomic area appropriate for the neurologic deficit had no clinical improvement by the time of discharge from the hospital; follow-up CT scans of these three patients confirmed infarction in the area of very low blood flow. Three patients with moderate blood flow reductions (15-45 ml/100 g/min) in the appropriate anatomic area had significant clinical improvement from their initial deficits and had normal follow-up CT scans. One patient studied 8 hours after stroke had increased blood flow (hyperemia) in the appropriate anatomic area and made no clinical recovery

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

    Science.gov (United States)

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

    2016-04-01

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

  9. Increase of cerebral blood flow at high altitude

    DEFF Research Database (Denmark)

    Lassen, N A

    1992-01-01

    CBF increases with acute hypoxia despite the opposing vasoconstrictor effects of the drop in pCO2 caused by hyperventilation. Maintaining normocapnia by adding CO2 the hypoxic CBF responsiveness about doubles. As we have shown recently by this test, the hypoxic CBF response is not blunted but rat...... vasodilatation cannot explain the usual (mild) form of AMS. But it may well be involved in the pathogenesis of the rare but severe cerebral form of AMS, as prolonged increased capillary pressure in vasodilated areas could lead to vasogenic cerebral edema....

  10. Assessing regional cerebral blood flow in depression using 320-slice computed tomography.

    Directory of Open Access Journals (Sweden)

    Yiming Wang

    Full Text Available While there is evidence that the development and course of major depressive disorder (MDD symptomatology is associated with vascular disease, and that there are changes in energy utilization in the disorder, the extent to which cerebral blood flow is changed in this condition is not clear. This study utilized a novel imaging technique previously used in coronary and stroke patients, 320-slice Computed-Tomography (CT, to assess regional cerebral blood flow (rCBF in those with MDD and examine the pattern of regional cerebral perfusion. Thirty nine participants with depressive symptoms (Hamilton Depression Rating Scale 24 (HAMD24 score > 20, and Self-Rating Depression Scale (SDS score > 53 and 41 healthy volunteers were studied. For all subjects, 3 ml of venous blood was collected to assess hematological parameters. Transcranial Doppler (TCD ultrasound was utilized to measure parameters of cerebral artery rCBFV and analyse the Pulsatility Index (PI. 16 subjects (8 =  MDD; 8 =  healthy also had rCBF measured in different cerebral artery regions using 320-slice CT. Differences among groups were analyzed using ANOVA and Pearson's tests were employed in our statistical analyses. Compared with the control group, whole blood viscosity (including high\\middle\\low shear rateand hematocrit (HCT were significantly increased in the MDD group. PI values in different cerebral artery regions and parameters of rCBFV in the cerebral arteries were decreased in depressive participants, and there was a positive relationship between rCBFV and the corresponding vascular rCBF in both gray and white matter. rCBF of the left gray matter was lower than that of the right in MDD. Major depression is characterized by a wide range of CBF impairments and prominent changes in gray matter blood flow. 320-slice CT appears to be a valid and promising tool for measuring rCBF, and could thus be employed in psychiatric settings for biomarker and treatment response purposes.

  11. Application of the Carreau viscosity model to the oscillatory flow in blood vessels

    Science.gov (United States)

    Tabakova, Sonia; Kutev, Nikolay; Radev, Stefan

    2015-11-01

    When studying the oscillatory flow in different types of blood vessels it is very important to know what type of the blood viscosity model has to be used. In general the blood viscosity is defined as a shear-thinning liquid, for which there exist different shear-dependent models, for example the Carreau model, which represents the viscosity as a non-linear function of the shear-rate. In some cases, however, the blood viscosity could be regarded as constant, i.e., the blood is treated as Newtonian fluid. The aim of the present work is to show theoretically and numerically some approximate limits of the Newtonian model application, when the blood vessel is assumed as a 2D straight tube. The obtained results are in agreement with other authors' numerical results based on similar blood viscosity models.

  12. Novel COL4A1 mutations cause cerebral small vessel disease by haploinsufficiency

    Science.gov (United States)

    Lemmens, Robin; Maugeri, Alessandra; Niessen, Hans W. M.; Goris, An; Tousseyn, Thomas; Demaerel, Philippe; Corveleyn, Anniek; Robberecht, Wim; van der Knaap, Marjo S.; Thijs, Vincent N.; Zwijnenburg, Petra J.G.

    2013-01-01

    Mutations in COL4A1 have been identified in families with hereditary small vessel disease of the brain presumably due to a dominant-negative mechanism. Here, we report on two novel mutations in COL4A1 in two families with porencephaly, intracerebral hemorrhage and severe white matter disease caused by haploinsufficiency. Two families with various clinical presentations of cerebral microangiopathy and autosomal dominant inheritance were examined. Clinical, neuroradiological and genetic investigations were performed. Electron microscopy of the skin was also performed. In one of the families, sequence analysis revealed a one base deletion, c.2085del, leading to a frameshift and a premature stopcodon, p.(Gly696fs). In the other family, a splice site mutation was identified, c.2194-1G>A, which most likely leads to skipping of an exon with a frameshift and premature termination as a result. In fibroblasts of affected individuals from both the families, nonsense-mediated decay (NMD) of the mutant COL4A1 messenger RNAs (mRNAs) and a clear reduction of COL4A1 protein expression were demonstrated, indicating haploinsufficiency of COL4A1. Moreover, thickening of the capillary basement membrane in the skin was documented, similar to reports in patients with COL4A1 missense mutations. These findings suggest haploinsufficiency, a different mechanism from the commonly assumed dominant-negative effect, for COL4A1 mutations as a cause of (antenatal) intracerebral hemorrhage and white matter disease. PMID:23065703

  13. Cerebral small vessel disease affects white matter microstructure in mild cognitive impairment.

    Science.gov (United States)

    Papma, Janne M; de Groot, Marius; de Koning, Inge; Mattace-Raso, Francesco U; van der Lugt, Aad; Vernooij, Meike W; Niessen, Wiro J; van Swieten, John C; Koudstaal, Peter J; Prins, Niels D; Smits, Marion

    2014-06-01

    Microstructural white matter deterioration is a frequent finding in mild cognitive impairment (MCI), potentially underlying default mode network (DMN) dysfunctioning. Thus far, microstructural damage in MCI has been attributed to Alzheimer's disease pathophysiology. A cerebrovascular role, in particular the role of cerebral small vessel disease (CSVD), received less interest. Here, we used diffusion tensor imaging (DTI) to examine the role of CSVD in microstructural deterioration within the normal appearing white matter (NAWM) in MCI. MCI patients were subdivided into those with (n = 20) and without (n = 31) macrostructural CSVD evidence on MRI. Using TBSS we performed microstructural integrity comparisons within the whole brain NAWM. Secondly, we segmented white matter tracts interconnecting DMN brain regions by means of automated tractography segmentation. We used NAWM DTI measures from these tracts as dependent variables in a stepwise-linear regression analysis, with structural and demographical predictors. Our results indicated microstructural deterioration within the anterior corpus callosum, internal and external capsule and periventricular white matter in MCI patients with CSVD, while in MCI patients without CSVD, deterioration was restricted to the right perforant path, a tract along the hippocampus. Within the full cohort of MCI patients, microstructure within the NAWM of the DMN fiber tracts was affected by the presence of CSVD. Within the cingulum along the hippocampal cortex we found a relationship between microstructural integrity and ipsilateral hippocampal volume and the extent of white matter hyperintensity. In conclusion, we found evidence of CSVD-related microstructural damage in fiber tracts subserving the DMN in MCI. PMID:24115179

  14. Association of Chronic Kidney Disease and Cerebral Small Vessel Disease with Cognitive Impairment in Elderly Patients with Type 2 Diabetes

    OpenAIRE

    Umemura, Toshitaka; Kawamura, Takahiko; Umegaki, Hiroyuki; Kawano, Naoko; Mashita, Shinichi; Sakakibara, Toshimasa; Hotta, Nigishi; Sobue, Gen

    2013-01-01

    Background/Aims In recent years, the relationship between chronic kidney disease (CKD) and cognitive impairment has been attracting attention. Cerebral small vessel disease (SVD) is also associated with an increased risk of cognitive impairment. However, it is still unknown whether CKD markers are associated with cognitive impairment independently of SVD in elderly diabetic patients. Methods Seventy-nine type 2 diabetic patients (mean age, 76.0 years) were enrolled in the present study. CKD w...

  15. Vascular bursts enhance permeability of tumour blood vessels and improve nanoparticle delivery

    Science.gov (United States)

    Matsumoto, Yu; Nichols, Joseph W.; Toh, Kazuko; Nomoto, Takahiro; Cabral, Horacio; Miura, Yutaka; Christie, R. James; Yamada, Naoki; Ogura, Tadayoshi; Kano, Mitsunobu R.; Matsumura, Yasuhiro; Nishiyama, Nobuhiro; Yamasoba, Tatsuya; Bae, You Han; Kataoka, Kazunori

    2016-06-01

    Enhanced permeability in tumours is thought to result from malformed vascular walls with leaky cell-to-cell junctions. This assertion is backed by studies using electron microscopy and polymer casts that show incomplete pericyte coverage of tumour vessels and the presence of intercellular gaps. However, this gives the impression that tumour permeability is static amid a chaotic tumour environment. Using intravital confocal laser scanning microscopy we show that the permeability of tumour blood vessels includes a dynamic phenomenon characterized by vascular bursts followed by brief vigorous outward flow of fluid (named ‘eruptions’) into the tumour interstitial space. We propose that ‘dynamic vents’ form transient openings and closings at these leaky blood vessels. These stochastic eruptions may explain the enhanced extravasation of nanoparticles from the tumour blood vessels, and offer insights into the underlying distribution patterns of an administered drug.

  16. Evaluation of immunohistochemical markers of lymphatic and blood vessels in canine mammary tumours.

    Science.gov (United States)

    Sleeckx, N; Van Brantegem, L; Fransen, E; Van den Eynden, G; Casteleyn, C; Veldhuis Kroeze, E; Van Ginneken, C

    2013-05-01

    Canine mammary tumours (CMTs) are the most common neoplasms in intact female dogs. Bitches with spontaneously arising CMTs represent a promising animal model for human breast cancer research. The aim of the present study was to develop an immunohistochemical protocol for the identification of blood and lymphatic vessels in CMTs. Antibodies specific for human lymphatic vessels (prox-1, lyve-1, podoplanin and D2-40) and blood vessels (von Willebrand factor [vWf], CD31 and CD34) were utilized. Serial sections of 18 samples (eight samples of normal canine mammary tissue, five benign and five malignant CMTs) were examined. Antibodies specific for podoplanin, D2-40 and CD34 showed no immunoreactivity with canine tissue. Prox-1 and CD31 were determined to be the most suitable markers for lymphatic and blood vessels, respectively. PMID:23123127

  17. Treatment of radiation exposure and regeneration medicine. Regeneration treatment of blood vessels by transplantation of autologous marrow monocytes

    International Nuclear Information System (INIS)

    Described are usefulness and future view of regenerative medicine in the treatment of radiation exposure as exemplified by the vascular regeneration by autologous marrow cell transplantation. Vascular endothelial cells (VEC), possessing a high ability to divide, are known sensitive to radiation, which gives damage of blood vessel to alter its permeability leading to apoptosis of VEC, organ/tissue injuries and final damages in the cerebral blood vessels, central nervous system and skin, the acute radiation syndrome (ARS). Authors present successful cases of patients with chronic limb ischemia in the Therapeutic Angiogenesis using Cell Transplantation Trial (TACT), to whom the treatment is conducted with transplantation of autologous marrow monocyte fraction containing endothelial progenitor cells that differentiate to VEC. As well, they touch on a case of the patient encountered in a nuclear accident, mentioning that VEC are found partly derived from the donor after heamatopoietic stem cell transplantation (HSCT). Efficacy of HSCT in a literature is reviewed and commented to be an only limited one in 31 patients of various radiation accidents. However, treatment of ARS where stem cells are target, with regenerative medicine will become more useful in future, as basic and clinical researches will provide requisite findings. (T.I.)

  18. Single photon emission CT perfusion imaging of cerebral blood flow of early syphilis patients

    Institute of Scientific and Technical Information of China (English)

    施辛; 吴锦昌; 刘增礼; 唐军; 苏玉华

    2003-01-01

    Objective To injvestigate the cerebral blood flow of patients with early syphilis. Methods 99Tcm-ECD as brain perfusion imaging agent was used in single photon emission computed tomography (SPECT) for 32 patients with early syphilis and 15 controls. Visual analyses were made on every BSPECT image. Results The 32 patients with early syphilis had general, patchy hypoperfusion of cerebral blood flow. Fourteen of the 32 patients had 48 episodes of marked patchy hypoperfusion of rCBF. The responsible areas of hypoperfusion in a patchy distribution involved the left frontal lobe (6 episodes), right frontal lobe (3), left parietal lobe (7), right parietal lobe (6), left temporal lobe (11), right temporal lobe (5), left occipital lobe (3), left basal ganglia (3), cerebellum (1), and nerve nuceus (1). No abnormality was found in the control group.Conclusions Cerebral blood flow abnormalities exist in patients with early syphilis. General patchy hypoperfusion on SPECT imaging is common.

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

    International Nuclear Information System (INIS)

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

  20. The relationship between cerebral blood flow and volume in humans

    DEFF Research Database (Denmark)

    Rostrup, Egill; Knudsen, Gitte M; Law, Ian;

    2005-01-01

    The purpose of this study was to establish the relationship between regional CBF and CBV at normal, resting cerebral metabolic rates. Eleven healthy volunteers were investigated with PET during baseline conditions, and during hyper- and hypocapnia. Values for rCBF and rCBV were obtained using (15)O...

  1. Altered Regional Cerebral Blood Flow in Chronic Whiplash Associated Disorders

    NARCIS (Netherlands)

    Vállez García, David; Doorduin, Janine; Willemsen, Antoon T.M.; Dierckx, Rudi A.j.o.; Otte, Andreas

    2016-01-01

    There is increasing evidence of central hyperexcitability in chronic whiplash-associated disorders (cWAD). However, little is known about how an apparently simple cervical spine injury can induce changes in cerebral processes. The present study was designed (1) to validate previous results showing a

  2. Regional cerebral blood flow and periventricular hyperintensity in silent cerebral infarction. Comparison with multi-infarct dementia

    International Nuclear Information System (INIS)

    In order to investigate relationship between regional cerebral blood flow (rCBF) and the white matter lesions on MRI in silent cerebral infarction, we quantitatively measured rCBF by 123I-IMP autoradiography method (IMP ARG method) and single photon emission tomography (SPECT) in 36 patients with silent cerebral infarction (SCI group), 22 patients with multi-infarct dementia (MID group), and 16 control subjects without periventricular hyperintensity (PVH) and lacunar infarction on MRI (CL group). Regions of interest (ROIs) on rCBF images were set in the frontal (F), temporal (T), parietal (P), occipital (O) cortex, and the cerebral white matter (W). The severity of PVH on MRI T2-weighted image was divided into four grades (grade 0-3). Though the frequency of hypertension was significantly higher in SCI group and MID group compared with CL group, no significant difference was seen in the mean age among these three groups. rCBF in the white matter and cerebral cortices except the occipital cortex in SCI group was significantly low compared with CL group (rCBFSCI/rCBFCL: W 0.87, F 0.87, T 0.87, P 0.88, O 0.92). rCBF in the white matter and cerebral cortices, especially in the white matter and frontal cortex, in MID group was significantly low compared with SCI group (rCBFMID/rCBFCL: W 0.69, F 0.71, T 0.74, P 0.75, O 0.81). The mean grade of PVH in MID group was significantly higher than that in SCI group (SCI 1.1 vs MID 2.5). The severity of PVH was significantly correlated with each rCBF in the white matter and cerebral cortices, especially in the white matter and frontal cortex. Our findings suggest that the quantitative measurement of rCBF by IMP ARG method is useful for the follow-up study in the patients with silent cerebral infarction as well as the evaluation of the severity of PVH on MRI. (author)

  3. Computational Fluid Dynamics Analysis of Pulsatile Blood Flow Behavior in Modelled Stenosed Vessels with Different Severities

    Directory of Open Access Journals (Sweden)

    Mohsen Mehrabi

    2012-01-01

    Full Text Available This study focuses on the behavior of blood flow in the stenosed vessels. Blood is modelled as an incompressible non-Newtonian fluid which is based on the power law viscosity model. A numerical technique based on the finite difference method is developed to simulate the blood flow taking into account the transient periodic behaviour of the blood flow in cardiac cycles. Also, pulsatile blood flow in the stenosed vessel is based on the Womersley model, and fluid flow in the lumen region is governed by the continuity equation and the Navier-Stokes equations. In this study, the stenosis shape is cosine by using Tu and Devil model. Comparing the results obtained from three stenosed vessels with 30%, 50%, and 75% area severity, we find that higher percent-area severity of stenosis leads to higher extrapressure jumps and higher blood speeds around the stenosis site. Also, we observe that the size of the stenosis in stenosed vessels does influence the blood flow. A little change on the cross-sectional value makes vast change on the blood flow rate. This simulation helps the people working in the field of physiological fluid dynamics as well as the medical practitioners.

  4. Tracing retinal blood vessels by matrix-forest theorem of directed graphs.

    Science.gov (United States)

    Cheng, Li; De, Jaydeep; Zhang, Xiaowei; Lin, Feng; Li, Huiqi

    2014-01-01

    This paper aims to trace retinal blood vessel trees in fundus images. This task is far from being trivial as the crossover of vessels are commonly encountered in image-based vessel networks. Meanwhile it is often crucial to separate the vessel tree structures in applications such as diabetic retinopathy analysis. In this work, a novel directed graph based approach is proposed to cast the task as label propagation over directed graphs, such that the graph is to be partitioned into disjoint sub-graphs, or equivalently, each of the vessel trees is traced and separated from the rest of the vessel network. Then the tracing problem is addressed by making novel usage of the matrix-forest theorem in algebraic graph theory. Empirical experiments on synthetic as well as publicly available fundus image datasets demonstrate the applicability of our approach. PMID:25333171

  5. HIFU procedures at moderate intensities-effect of large blood vessels

    International Nuclear Information System (INIS)

    A three-dimensional computational model is presented for studying the efficacy of high-intensity focused ultrasound (HIFU) procedures targeted near large blood vessels. The analysis applies to procedures performed at intensities below the threshold for cavitation, boiling and highly nonlinear propagation, but high enough to increase tissue temperature a few degrees per second. The model is based upon the linearized KZK equation and the bioheat equation in tissue. In the blood vessel the momentum and energy equations are satisfied. The model is first validated in a tissue phantom, to verify the absence of bubble formation and nonlinear effects. Temperature rise and lesion-volume calculations are then shown for different beam locations and orientations relative to a large vessel. Both single and multiple ablations are considered. Results show that when the vessel is located within about a beam width (few mm) of the ultrasound beam, significant reduction in lesion volume is observed due to blood flow. However, for gaps larger than a beam width, blood flow has no major effect on the lesion formation. Under the clinically representative conditions considered, the lesion volume is reduced about 40% (relative to the no-flow case) when the beam is parallel to the blood vessel, compared to about 20% for a perpendicular orientation. Procedures involving multiple ablation sites are affected less by blood flow than single ablations. The model also suggests that optimally focused transducers can generate lesions that are significantly larger (>2 times) than the ones produced by highly focused beams

  6. HIFU procedures at moderate intensities-effect of large blood vessels

    Energy Technology Data Exchange (ETDEWEB)

    Hariharan, P [Mechanical, Industrial, and Nuclear Engineering Department, University of Cincinnati, Cincinnati, OH (United States); Myers, M R [Division of Solid and Fluid Mechanics, Center for Devices and Radiological Health, US Food and Drug Administration, 10903 New Hampshire Avenue, Building 62, Silver Spring, MD 20993-0002 (United States); Banerjee, R K [Mechanical, Industrial, and Nuclear Engineering Department, University of Cincinnati, Cincinnati, OH (United States)

    2007-07-21

    A three-dimensional computational model is presented for studying the efficacy of high-intensity focused ultrasound (HIFU) procedures targeted near large blood vessels. The analysis applies to procedures performed at intensities below the threshold for cavitation, boiling and highly nonlinear propagation, but high enough to increase tissue temperature a few degrees per second. The model is based upon the linearized KZK equation and the bioheat equation in tissue. In the blood vessel the momentum and energy equations are satisfied. The model is first validated in a tissue phantom, to verify the absence of bubble formation and nonlinear effects. Temperature rise and lesion-volume calculations are then shown for different beam locations and orientations relative to a large vessel. Both single and multiple ablations are considered. Results show that when the vessel is located within about a beam width (few mm) of the ultrasound beam, significant reduction in lesion volume is observed due to blood flow. However, for gaps larger than a beam width, blood flow has no major effect on the lesion formation. Under the clinically representative conditions considered, the lesion volume is reduced about 40% (relative to the no-flow case) when the beam is parallel to the blood vessel, compared to about 20% for a perpendicular orientation. Procedures involving multiple ablation sites are affected less by blood flow than single ablations. The model also suggests that optimally focused transducers can generate lesions that are significantly larger (>2 times) than the ones produced by highly focused beams.

  7. HIFU procedures at moderate intensities--effect of large blood vessels.

    Science.gov (United States)

    Hariharan, P; Myers, M R; Banerjee, R K

    2007-06-21

    A three-dimensional computational model is presented for studying the efficacy of high-intensity focused ultrasound (HIFU) procedures targeted near large blood vessels. The analysis applies to procedures performed at intensities below the threshold for cavitation, boiling and highly nonlinear propagation, but high enough to increase tissue temperature a few degrees per second. The model is based upon the linearized KZK equation and the bioheat equation in tissue. In the blood vessel the momentum and energy equations are satisfied. The model is first validated in a tissue phantom, to verify the absence of bubble formation and nonlinear effects. Temperature rise and lesion-volume calculations are then shown for different beam locations and orientations relative to a large vessel. Both single and multiple ablations are considered. Results show that when the vessel is located within about a beam width (few mm) of the ultrasound beam, significant reduction in lesion volume is observed due to blood flow. However, for gaps larger than a beam width, blood flow has no major effect on the lesion formation. Under the clinically representative conditions considered, the lesion volume is reduced about 40% (relative to the no-flow case) when the beam is parallel to the blood vessel, compared to about 20% for a perpendicular orientation. Procedures involving multiple ablation sites are affected less by blood flow than single ablations. The model also suggests that optimally focused transducers can generate lesions that are significantly larger (>2 times) than the ones produced by highly focused beams. PMID:17664556

  8. Evaluation of regional cerebral blood flow in patient with atypical senile dementia with asymmetrical calcification.

    Science.gov (United States)

    Shoyama, Masaru; Ukai, Satoshi; Shinosaki, Kazuhiro

    2015-12-01

    We report an 83-year-old woman with atypical senile dementia with Fahr-type calcification. Brain computed tomography demonstrated asymmetrical calcification predominant in the basal ganglia on the right side and pronounced diffuse cortical atrophy in the frontotemporal areas. The patient was clinically diagnosed with diffuse neurofibrillary tangles with calcification. Brain single photon emission computed tomography findings revealed that cerebral blood flow was reduced on the right side, as compared with the left side, in widespread areas. Hemispheric asymmetry in both calcification and cerebral blood flow suggests a relationship between calcification and vascular changes. PMID:25737312

  9. In vivo quantitation of regional cerebral blood flow in glioma and cerebral infarction: validation of the HIPDm-SPECT method

    International Nuclear Information System (INIS)

    Iodine-123 labeled hydroxyiodopropyldiamine (HIPDm) is a diffusible indicator with an 85%-90% extraction fraction and stable retention in the brain for more than 2 hr. Equilibrium-phase imaging and quantitation using single-photon emission computed tomographic (SPECT) scanning defined a distribution of HIPDm in proportion to regional cerebral blood flow (rCBF). Studies in calves affirmed a close correspondence (r . 0.97) in calculated rCBF between HIPDm and microspheres using the tissue deposition-arterial input function microsphere methodology. Using this same mathematical analysis in vivo, reproducible rCBF data within the expected range of normal were obtained on repeated studies in the same nonhuman primate. With a diffuse encephalopathy secondary to subarachnoid blood, a bilaterally symmetric decrease in rCBF was present. A prominent focal decrease in HIPDm accumulation and calculated rCBF was noted with cerebral infarction in the distribution of a ligated middle cerebral artery. Patient studies with glioma revealed diminished HIPDm accumulation due to decreased flow and/or pH in the region of the neoplasm as well as in the associated vasogenic edema and overlying gray matter

  10. An experimental system for the study of ultrasound exposure of isolated blood vessels

    International Nuclear Information System (INIS)

    An experimental system designed for the study of the effects of diagnostic or therapeutic ultrasound exposure on isolated blood vessels in the presence or absence of intraluminal contrast agent is described. The system comprised several components. A microscope was used to monitor vessel size (and thus vessel functionality), and potential leakage of intraluminal 70 kDa FITC-dextran fluorescence marker. A vessel chamber allowed the mounting of an isolated vessel whilst maintaining its viability, with pressure regulation for the control of intraluminal pressure and induction of flow for the infusion of contrast microbubbles. A fibre-optic hydrophone sensor mounted on the vessel chamber using a micromanipulator allowed pre-exposure targeting of the vessel to within 150 µm, and monitoring of acoustic cavitation emissions during exposures. Acoustic cavitation was also detected using changes in the ultrasound drive voltage and by detection of audible emissions using a submerged microphone. The suitability of this system for studying effects in the isolated vessel model has been demonstrated using a pilot study of 6 sham exposed and 18 high intensity focused ultrasound exposed vessels, with or without intraluminal contrast agent (SonoVue) within the vessels. (paper)

  11. Blood vessel extraction and optic disc removal using curvelet transform and kernel fuzzy c-means.

    Science.gov (United States)

    Kar, Sudeshna Sil; Maity, Santi P

    2016-03-01

    This paper proposes an automatic blood vessel extraction method on retinal images using matched filtering in an integrated system design platform that involves curvelet transform and kernel based fuzzy c-means. Since curvelet transform represents the lines, the edges and the curvatures very well and in compact form (by less number of coefficients) compared to other multi-resolution techniques, this paper uses curvelet transform for enhancement of the retinal vasculature. Matched filtering is then used to intensify the blood vessels' response which is further employed by kernel based fuzzy c-means algorithm that extracts the vessel silhouette from the background through non-linear mapping. For pathological images, in addition to matched filtering, Laplacian of Gaussian filter is also employed to distinguish the step and the ramp like signal from that of vessel structure. To test the efficacy of the proposed method, the algorithm has also been applied to images in presence of additive white Gaussian noise where the curvelet transform has been used for image denoising. Performance is evaluated on publicly available DRIVE, STARE and DIARETDB1 databases and is compared with the large number of existing blood vessel extraction methodologies. Simulation results demonstrate that the proposed method is very much efficient in detecting the long and the thick as well as the short and the thin vessels with an average accuracy of 96.16% for the DRIVE and 97.35% for the STARE database wherein the existing methods fail to extract the tiny and the thin vessels. PMID:26848729

  12. Prevent Diabetes Problems: Keep Your Heart and Blood Vessels Healthy

    Science.gov (United States)

    ... Research Training & Career Development Grant programs for students, postdocs, and faculty Research at NIDDK Labs, faculty, and ... Top ] What can I do to prevent or control PAD? Don't smoke. Keep blood glucose and ...

  13. Prevent Diabetes Problems: Keep Your Heart and Blood Vessels Healthy

    Science.gov (United States)

    ... Association of Diabetes Educators Academy of Nutrition and Dietetics National Heart Lung and Blood Institute American Diabetes ... for Scientists Current Funding Opportunities Funded Grants & Grant History Funding Process Research Programs & Contacts Research Training & Career ...

  14. Aging changes in the heart and blood vessels

    Science.gov (United States)

    ... Some of the things that make your heart work harder are: Certain medicines Emotional stress Physical exertion Illness Infections Injuries COMMON PROBLEMS Angina (chest pain caused by temporarily reduced blood flow to the ...

  15. Measurement of cerebral blood flow in the pig by the Xe-133 clearance technique

    International Nuclear Information System (INIS)

    The Xe-133 clearance technique is used to measure cerebral blood flow in the pig, which often serves as an experimental animal for cardiovascular research. The clearance curves are fitted by a two-exponential model. However, the fitted parameters are incompatible with a two-compartmental model: the values found for the parameters depend on the length of the clearance curve analysed. The discrepancies are thought to be consequences of the heterogeneity of cerebral blood flow and of mathematical problems of parameter identification. The non-validity of the relative weight of the fast clearance component as an anatomical or functional parameter is demonstrated. The use of the mean time constant, mean transit time, mean decay constant and initial slope for determination of cerebral blood flow rates is discussed. The mean cerebral blood flow of the anaesthetized pig measured by the clearance technique is found to be lower than the blood flow measured by means of a flow probe around the common carotid artery (with the external carotid artery tied off). The existence of a significant arteriovenous shunt flow is postulated. (orig.)

  16. Aquaporin 4 expression and ultrastructure of the blood-brain barrier following cerebral contusion injury

    Institute of Scientific and Technical Information of China (English)

    Xinjun Li; Yangyun Han; Hong Xu; Zhongshu Sun; Zengjun Zhou; Xiaodong Long; Yumin Yang; Linbo Zou

    2013-01-01

    This study aimed to investigate aquaporin 4 expression and the ultrastructure of the blood-brain barrier at 2–72 hours following cerebral contusion injury, and correlate these changes to the formation of brain edema. Results revealed that at 2 hours after cerebral contusion and laceration injury, aquaporin 4 expression significantly increased, brain water content and blood-brain barrier permeability increased, and the number of pinocytotic vesicles in cerebral microvascular endothelial cells increased. In addition, the mitochondrial accumulation was observed. As contusion and laceration injury became aggravated, aquaporin 4 expression continued to increase, brain water content and blood-brain barrier permeability gradually increased, brain capillary endothelial cells and astrocytes swelled, and capillary basement membrane injury gradually increased. The above changes were most apparent at 12 hours after injury, after which they gradually attenuated. Aquaporin 4 expression positively correlated with brain water content and the blood-brain barrier index. Our experimental findings indicate that increasing aquaporin 4 expression and blood-brain barrier permeability after cerebral contusion and laceration injury in humans is involved in the formation of brain edema.

  17. Cerebral blood flow autoregulation in patients with acute bacterial meningitis

    DEFF Research Database (Denmark)

    Møller, Kirsten

    2001-01-01

    Ph.d. afhandlingen omhandler sammenhængen mellem hjernens blodtilførsel (CBF) og middelarterietrykket (MAP) hos patienter med akut bakteriel meningitis. Hos raske er CBF uafhængig af MAP, hvilket kaldes CBF autoregulation. Svækket autoregulation antages at øge risikoen for cerebral hypoperfusion og...... iskæmi under episoder med lavt MAP, og for cerebral hyperperfusion og vasogent ødem ved højt MAP. CBF autoregulationen undersøgtes hos tyve voksne patienter med akut bakteriel meningitis i den tidlige sygdomsfase (<24 timer efter diagnostisk lumbalpunktur). Idet autoregulationen fandtes svækket hos...... meningitis, men retableres ved klinisk restitution. Autoregulationen kan endvidere delvis retableres ved akut hyperventilation. Fundene har potentiel betydning for valg af supportiv terapi hos patienter med meningitis....

  18. Regional cerebral blood flow measurement with intravenous [15O]water bolus and [18F]fluoromethane inhalation

    International Nuclear Information System (INIS)

    In 20 patients with ischemic cerebrovascular disease, classic migraine, or angiomas, we compared paired dynamic positron emission tomographic measurements of regional cerebral blood flow using both [15O]water and [18F]fluoromethane as tracers. Cerebral blood flow was also determined according to the autoradiographic technique with a bolus injection of [15O]water. There were reasonable overall correlations between dynamic [15O]water and [18F]fluoromethane values for cerebral blood flow (r = 0.82) and between dynamic and autoradiographic [15O]water values for cerebral blood flow (r = 0.83). We found a close correspondence between abnormal pathologic findings and visually evaluated cerebral blood flow tomograms obtained with the two tracers. On average, dynamic [15O]water cerebral blood flow was 6% lower than that measured with [18F]fluoromethane. There also was a general trend toward a greater underestimation with [15O]water in high-flow areas, particularly in hyperemic areas, probably due to incomplete first-pass extraction of [15O]water. Underestimation was not detected in low-flow areas or in the cerebellum. Absolute cerebral blood flow values were less closely correlated between tracers and techniques than cerebral blood flow patterns. The variability of the relation between absolute flow values was probably caused by confounding effects of the variation in the circulatory delay time. The autoradiographic technique was most sensitive to this type error

  19. The postural reduction in middle cerebral artery blood velocity is not explained by PaCO2

    DEFF Research Database (Denmark)

    Immink, R V; Secher, N H; Roos, C M; Pott, F; Madsen, P L; van Lieshout, J J

    2006-01-01

    In the normocapnic range, middle cerebral artery mean velocity (MCA Vmean) changes approximately 3.5% per mmHg carbon-dioxide tension in arterial blood (PaCO2) and a decrease in PaCO2 will reduce the cerebral blood flow by vasoconstriction (the CO2 reactivity of the brain). When standing up MCA...

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

    International Nuclear Information System (INIS)

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

  1. Regional cerebral blood flow measurement by N-isopropyl-p-[123I] iodoamphetamine

    International Nuclear Information System (INIS)

    Eight patients with hemiplegia in chronic stages were studied with N-isopropyl-p-[123I] iodoamphetamine (IMP) and single-photon emission computed tomography (SPECT) comparing with X-ray CT findings. In three patients, focal decreases of IMP were observed and these areas were larger than the abnormal areas found by X-ray CT. In the other five patients, hemispherical low perfusion of IMP was observed by SPECT, but X-ray CT showed severe atrophy with normal density. In two patients, cerebral angiography showed no abnormalities in the arterial phase. Regional cerebral blood flow measurement using IMP would be of great value in evaluating abnormal cerebral functions in the chronic state of acute infantile hemiplegia and cerebral palsy. (author)

  2. Psychiatric and subjective symptoms and cerebral blood flow in patients with chronic cerebral infarction after treatment with Ca antagonist (nilvadipine). Quantitative measurement of cerebral blood flow by the 123IMP-SPECT ARG method

    International Nuclear Information System (INIS)

    Psychiatric and subjective symptoms such as headache, dizziness, lack of spontaneity, anxiety, and a depressive state are often found in patients with chronic cerebral infarction. Some Ca antagonists are reported to relieve such symptoms. The purpose of the present study was to investigate the relationship between psychiatric and subjective symptoms and cerebral blood flow (CBF) in cerebral infarction and to evaluate the clinical effects of Ca antagonists from the standpoint of the cerebral circulation. Nilvadipine was administered to is patients with chronic cerebral infarction and their CBF was measured by the 123IMP-SPECT ARG method before and at 8 weeks after the nilvadipine treatment. The CBF in patients with hypertension was increased by 11% after giving nilvadipine. Patients without hypertension showed no tendency for elevation of their CBF. Patients who were relieved from some psychiatric symptoms revealed a 14% increase of CBF in all cortical regions, and a significant increase was noted in the frontal and temporal regions. In other patients without changes in psychiatric symptoms, the CBF did not increase in any of the cortical regions. No relationship between symptoms and CBF was observed in any of the patients with subjective symptoms. Our study demonstrated a close correlation between psychiatric symptoms and CBF. We speculate that psychiatric symptoms in chronic cerebral infarction may reflect diffuse brain dysfunctions. We also conclude that nilvadipine is more effective in relieving psychiatric symptoms in patients with hypertensive cerebral infarction. It is inferred that nilvadipine may be more effective in relieving psychiatric symptoms in patients with hypertension. (author)

  3. In vivo analysis of physiological 3D blood flow of cerebral veins

    Energy Technology Data Exchange (ETDEWEB)

    Schuchardt, Florian; Schroeder, Laure; Baeuerle, Jochen; Harloff, Andreas [University Medical Centre, Department of Neurology, Freiburg (Germany); Anastasopoulos, Constantin [University Medical Center, Department of Neuropaediatrics and Muscle Disorders, Freiburg (Germany); University Medical Centre, Department of Neuroradiology, Freiburg (Germany); Markl, Michael [Northwestern University, Department of Radiology, Feinberg School of Medicine and McCormick School of Engineering, Chicago, IL (United States); Hennemuth, Anja; Drexl, Johann [Fraunhofer MEVIS, Bremen (Germany); Valdueza, Jose M. [Neurological Center, Segeberger Kliniken, Bad Segeberg (Germany); Mader, Irina [University Medical Centre, Department of Neuroradiology, Freiburg (Germany)

    2015-08-15

    To visualize and quantify physiological blood flow of intracranial veins in vivo using time-resolved, 3D phase-contrast MRI (4D flow MRI), and to test measurement accuracy. Fifteen healthy volunteers underwent repeated ECG-triggered 4D flow MRI (3 Tesla, 32-channel head coil). Intracranial venous blood flow was analysed using dedicated software allowing for blood flow visualization and quantification in analysis planes at the superior sagittal, straight, and transverse sinuses. MRI was evaluated for intra- and inter-observer agreement and scan-rescan reproducibility. Measurements of the transverse sinuses were compared with transcranial two-dimensional duplex ultrasound. Visualization of 3D blood flow within cerebral sinuses was feasible in 100 % and within at least one deep cerebral vein in 87 % of the volunteers. Blood flow velocity/volume increased along the superior sagittal sinus and was lower in the left compared to the right transverse sinus. Intra- and inter-observer reliability and reproducibility of blood flow velocity (mean difference 0.01/0.02/0.02 m/s) and volume (mean difference 0.0002/-0.0003/0.00003 l/s) were good to excellent. High/low velocities were more pronounced (8 % overestimation/9 % underestimation) in MRI compared to ultrasound. Four-dimensional flow MRI reliably visualizes and quantifies three-dimensional cerebral venous blood flow in vivo and is promising for studies in patients with sinus thrombosis and related diseases. (orig.)

  4. Role of thalamic diffusion for disease differentiation between multiple sclerosis and ischemic cerebral small vessel disease

    Energy Technology Data Exchange (ETDEWEB)

    Oeztoprak, Bilge; Oeztoprak, Ibrahim; Salk, Ismail [Cumhuriyet University School of Medicine, Department of Radiology, Sivas (Turkey); Topalkara, Kamil [Bayindir Hospital, Department of Neurology, Ankara (Turkey); Erkoc, Mustafa F. [Bozok University School of Medicine, Department of Radiology, Yozgat (Turkey)

    2015-04-01

    Cerebral small vessel disease (CSVD) and multiple sclerosis (MS) both harbor multiple, T2-hyperintense white matter lesions on conventional magnetic resonance imaging (MRI).We aimed to determine the microstructural changes via diffusion-weighted imaging (DWI) in normal appearing thalami. We hypothesized that the apparent diffusion coefficient (ADC) values would be different in CSVD and MS, since the extent of arterial involvement is different in these two diseases. DWI was performed for 50 patients with CSVD and 35 patients with MS along with gender- and age-matched controls whose conventional MRI revealed normal findings. DWI was done with 1.5 Tesla MR devices using echo planar imaging (EPI) for b = 0, 1000 s/mm{sup 2}. ADC values were obtained from the thalami which appeared normal on T2-weighted and FLAIR images. Standard oval regions of interest (ROIs) of 0.5 cm{sup 2} which were oriented parallel to the long axis of the thalamus were used for this purpose. The mean ADC value of the thalamus was (0.99 ± 0.16) x 10{sup -3} mm{sup 2}/s in patients with CSVD, whereas the mean ADC value was (0.78 ± 0.06) x 10{sup -3} mm{sup 2}/s in the control group. The mean ADC value was significantly higher in patients with CSVD compared to the controls (p < 0.001). The mean ADC values of the thalamus were (0.78 ± 0.08) x 10{sup -3} mm{sup 2}/s in MS patients, and (0.75 ± 0.08) x 10{sup -3} mm{sup 2}/s in the control group, which are not significantly different (p > 0.05). Our study revealed a difference in the diffusion of the thalami between CSVD and MS. DWI may aid in the radiological disease differentiation. (orig.)

  5. Role of thalamic diffusion for disease differentiation between multiple sclerosis and ischemic cerebral small vessel disease

    International Nuclear Information System (INIS)

    Cerebral small vessel disease (CSVD) and multiple sclerosis (MS) both harbor multiple, T2-hyperintense white matter lesions on conventional magnetic resonance imaging (MRI).We aimed to determine the microstructural changes via diffusion-weighted imaging (DWI) in normal appearing thalami. We hypothesized that the apparent diffusion coefficient (ADC) values would be different in CSVD and MS, since the extent of arterial involvement is different in these two diseases. DWI was performed for 50 patients with CSVD and 35 patients with MS along with gender- and age-matched controls whose conventional MRI revealed normal findings. DWI was done with 1.5 Tesla MR devices using echo planar imaging (EPI) for b = 0, 1000 s/mm2. ADC values were obtained from the thalami which appeared normal on T2-weighted and FLAIR images. Standard oval regions of interest (ROIs) of 0.5 cm2 which were oriented parallel to the long axis of the thalamus were used for this purpose. The mean ADC value of the thalamus was (0.99 ± 0.16) x 10-3 mm2/s in patients with CSVD, whereas the mean ADC value was (0.78 ± 0.06) x 10-3 mm2/s in the control group. The mean ADC value was significantly higher in patients with CSVD compared to the controls (p < 0.001). The mean ADC values of the thalamus were (0.78 ± 0.08) x 10-3 mm2/s in MS patients, and (0.75 ± 0.08) x 10-3 mm2/s in the control group, which are not significantly different (p > 0.05). Our study revealed a difference in the diffusion of the thalami between CSVD and MS. DWI may aid in the radiological disease differentiation. (orig.)

  6. Pattern and Rate of Cognitive Decline in Cerebral Small Vessel Disease: A Prospective Study.

    Directory of Open Access Journals (Sweden)

    Andrew J Lawrence

    Full Text Available Cognitive impairment, predominantly affecting processing speed and executive function, is an important consequence of cerebral small vessel disease (SVD. To date, few longitudinal studies of cognition in SVD have been conducted. We determined the pattern and rate of cognitive decline in SVD and used the results to determine sample size calculations for clinical trials of interventions reducing cognitive decline.121 patients with MRI confirmed lacunar stroke and leukoaraiosis were enrolled into the prospective St George's Cognition And Neuroimaging in Stroke (SCANS study. Patients attended one baseline and three annual cognitive assessments providing 36 month follow-up data. Neuropsychological assessment comprised a battery of tests assessing working memory, long-term (episodic memory, processing speed and executive function. We calculated annualized change in cognition for the 98 patients who completed at least two time-points.Task performance was heterogeneous, but significant cognitive decline was found for the executive function index (p<0.007. Working memory and processing speed decreased numerically, but not significantly. The executive function composite score would require the smallest samples sizes for a treatment trial with an aim of halting decline, but this would still require over 2,000 patients per arm to detect a 30% difference with power of 0.8 over a three year follow-up.The pattern of cognitive decline seen in SVD over three years is consistent with the pattern of impairments at baseline. Rates of decline were slow and sample sizes would need to be large for clinical trials aimed at halting decline beyond initial diagnosis using cognitive scores as an outcome measure. This emphasizes the importance of more sensitive surrogate markers in this disease.

  7. Evaluation of the Extension of the Cerebral Blood Flow and its Main Parameters

    CERN Document Server

    Gersten, A

    1999-01-01

    Among the major factors controlling the cerebral blood flow (CBF) - cerebral perfusion pressure, arterial partial pressure of oxygen (PaO2), cerebral metabolism, arterial partial pressure of carbon dioxide (PaCO2), and cardiac output, the effect of PaCO2 is peculiar in being independent of autoregulatory CBF mechanisms and it allows to explore the full range of the CBF. We have developed a simple physical model, and have derived a simple four parameter formula, relating the CBF to PaCO2. The parameters can be extracted in an easy way, directly from the experimental data. With this model five experimental data sets of human, rats, baboons and dogs were well fitted. The same type of parametrization was also used successfully for fitting experimental data of PaO2 of dogs. We have also looked on the dependence of the parameters on other factors and were able to evaluate their dependence on the mean arterial blood pressure.

  8. Primo Vascular System Accompanying a Blood Vessel from Tumor Tissue and a Method to Distinguish It from the Blood or the Lymph System

    OpenAIRE

    Jaekwan Lim; Sungwoo Lee; Zhendong Su; Hong Bae Kim; Jung Sun Yoo; Kwang-Sup Soh; Sungchul Kim; Yeon Hee Ryu

    2013-01-01

    A primo vessel was observed in the abdominal cavity in the lung cancer mouse model, and its function as an extra metastatic path was observed. In this work, we found a primo vessel accompanying a blood vessel emanating from a tumor in the skin. We also presented simple and efficient criteria to distinguish a primo vessel from a blood or a lymph vessel and from a nerve. The criteria for using DAPI and Phalloidin will be useful in clinical situations to find and identify the primo vessels among...

  9. Features of cerebral blood flow, cardiac arrhythmias and conduction disturbances in patients with essential hypertension stage II associated with occlusive and stenotic lesions of brachiocephalic arteries

    Directory of Open Access Journals (Sweden)

    Vizir V.A.

    2015-09-01

    Full Text Available Arterial hypertension is the most common disease of the cardiovascular system in industrially advanced countries. With the aim to determine the characteristics of cerebral blood flow, disorders of cardiac rhythm and conduction in patients with stage 2 hypertension associated with stenotic and occlusive lesions of brachiocephalic arteries, cerebral blood flow indicators were studied in 87 patients using duplex scanning of extracranial arteries and Holter ECG monitoring. It was established that linear blood flow velocity was considerably decreased in the basins of the internal and common carotid artery; cerebral blood flow asymmetry was present in the course of the internal carotid artery. Evidence-based differences in structure of arrhythmias were revealed by single and paired ventricular extrasystoles, as well as episodes of unstable ventricular tachycardia. All this indicates the progressive decrease of elasticity and tonicity of vessel walls, intensified rigidity and sinuosity of carotid arteries, more severe disorders of cardiac rhythm and conduction in case of simultaneous hypertension and atherosclerotic lesion of brachiocephalic arteries.

  10. Collagen-based scaffolds for tissue engineering of small-diameter blood vessels

    OpenAIRE

    Buttafoco, Laura

    2005-01-01

    Atherosclerotic vascular disease, including peripheral and coronary artery disease, is the main cause of morbidity and mortality in the Western society. Although synthetic blood vessel prostheses are successfully being used for large-diameter vascular reconstructions, until now no functional small-diameter (< 6 mm) artificial vascular graft is available. Autologous veins and arteries are currently being used as vessel substitutes, but limitations in arteries supply and compliance mismatch are...

  11. Synthetic reconstruction of dynamic blood flow in cortical arteries using optical coherence tomography for the evaluation of vessel compliance

    Science.gov (United States)

    Baraghis, Edward; Bolduc, Virginie; Gillis, Marc-Antoine; Srinivasan, Vivek J.; Thorin, Éric; Boudoux, Caroline; Lesage, Frédéric

    2011-03-01

    Optical Coherence Tomography (OCT) has recently been used to produce 3D angiography of microvasculature in the rodent brain in-vivo and blood flow maps of large vessels. Key enabling developments were novel algorithms for detecting Doppler shifts produced by moving scatterers and new scanning protocols tailored to increase sensitivity to small flow speeds. These progresses were pushed by the need for a non invasive imaging modality to monitor quantitative blood flow at a higher resolution and a greater depth than could be achieved by other means. The rationale for this work originates from new hypotheses regarding the role of blood regulation in neurodegenerative diseases and from current investigations of animal models of vascular degeneration. In this work we demonstrate the synthetic reconstruction of dynamic blood flow in mice over the course of a single cardiac cycle in an 800μm wide by ~ 3mm deep B-Frame slice with a lateral resolution of 10μm and a depth resolution of 7μm. Images were taken using a cranial window over the exposed parietal bone of mice skull. Electrocardiography (ECG) recordings were co registered with the OCT A lines at high temporal resolution. QRS peak detection was then used to locate the time value of each A-line in the cardiac cycle and to reconstruct a synthetic temporal frame over one cardiac cycle. Doppler speed in this cardiac cycle was used to measure temporal variations of flow inside arteries and of their area. Three dimensional volume scans yielded measurements of quantitative blood flow on the same arteries. Using these informations a measure of compliance could be established. Comparing measures between atherosclerotic (ATX) and wild type (WT) mice revealed higher blood flow in WT mice, suggested lower systemic compliance in the ATX group but higher compliance of cerebral vasculature on these mice. These results are consistent with expectations showing that OCT is a potential tool for in-vivo arterial compliance evaluation.

  12. Changes in cerebral artery blood flow velocity after intermittent cerebrospinal fluid drainage.

    OpenAIRE

    Kempley, S T; Gamsu, H R

    1994-01-01

    Doppler ultrasound was used to measure blood flow velocity in the anterior cerebral artery of six premature infants with posthaemorrhagic hydrocephalus, before and after intermittent cerebrospinal fluid (CSF) drainage, on 23 occasions. There was a significant increase in mean blood flow velocity after the drainage procedures (+5.6 cm/s, 95% confidence interval +2.9 to +8.3 cm/s), which was accompanied by a decrease in velocity waveform pulsatility. CSF pressure also fell significantly. In pat...

  13. Aging changes in the heart and blood vessels

    Science.gov (United States)

    ... for treating high blood pressure, high cholesterol or diabetes. Reduce or stop smoking. Men between the ages of 65 to 75 who have ever smoked should be screened for aneurysms in their abdominal aorta. Get more exercise: Exercise may help prevent obesity, ...

  14. Cerebral blood flow in acute and chronic ischemic stroke using xenon-133 inhalation tomography

    DEFF Research Database (Denmark)

    Vorstrup, S; Paulson, O B; Lassen, N A

    1986-01-01

    Serial measurements of cerebral blood flow (CBF) were performed in 12 patients with acute symptoms of ischemic cerebrovascular disease. CBF was measured by xenon-133 inhalation and single photon emission computer tomography. Six patients had severe strokes and large infarcts on the CT scan. They...

  15. Effect of axillary blockade on regional cerebral blood flow during static handgrip

    DEFF Research Database (Denmark)

    Friedman, D B; Friberg, L; Mitchell, J H;

    1991-01-01

    Regional cerebral blood flow (rCBF) was determined at rest and during static handgrip before and after regional blockade with lidocaine. A fast rotating single photon emission computer tomograph system with 133Xe inhalation was used at orbitomeatal plane (OM) +2.5 and +6.5 cm in eight subjects. M...

  16. Cognitive profiles and regional cerebral blood flow patterns in dementia of the Alzheimer type

    DEFF Research Database (Denmark)

    Waldemar, G; Bruhn, P; Schmidt, E;

    1994-01-01

    Individual cognitive profiles and correlations between cognitive functions and regional cerebral blood flow (rCBF) were analyzed in 20 consecutive patients with a clinical diagnosis of probable Alzheimer's disease (AD). CBF was measured with high resolution single photon emission computed...

  17. Heterogeneity of neocortical cerebral blood flow deficits in dementia of the Alzheimer type

    DEFF Research Database (Denmark)

    Waldemar, G; Bruhn, P; Kristensen, M;

    1994-01-01

    Regional cerebral blood flow (rCBF) was measured with high resolution brain dedicated single photon emission computer tomography (SPECT) and [99mTc]-d,l-hexamethyl-propylene-amine-oxime (HMPAO) in 25 patients with probable Alzheimer's disease and in 25 control subjects, selected according to...

  18. A method for calculating regional cerebral blood flow from emission computed tomography of inert gas concentrations

    DEFF Research Database (Denmark)

    Celsis, P; Goldman, T; Henriksen, L; Lassen, N A

    1981-01-01

    Emission tomography of positron or gamma emitting inert gases allows calculation of regional cerebral blood flow (rCBF) in cross-sectional slices of human brain. An algorithm is presented for rCBF calculations from a sequence of time averaged tomograms using inhaled 133Xe. The approach is designe...

  19. Influence of caffeine and caffeine withdrawal on headache and cerebral blood flow velocities

    NARCIS (Netherlands)

    Couturier, EGM; Laman, DM; vanDuijn, MAJ; vanDuijn, H

    1997-01-01

    Caffeine consumption may cause headache, particularly migraine. Its withdrawal also produces headaches and may be related to weekend migraine attacks. Transcranial Doppler sonography (TCD) has shown changes in cerebral blood flow velocities (BFV) during and between attacks of migraine. In order to e

  20. Cerebral blood flow during submaximal and maximal dynamic exercise in humans

    DEFF Research Database (Denmark)

    Thomas, S N; Schroeder, T; Secher, N H; Mitchell, J H

    1989-01-01

    Cerebral blood flow (CBF) in humans was measured at rest and during dynamic exercise on a cycle ergometer corresponding to 56% (range 27-85) of maximal O2 uptake (VO2max). Exercise bouts were performed by 16 male and female subjects, lasted 15 min each, and were carried out in a semisupine positi...

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

    DEFF Research Database (Denmark)

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

    1987-01-01

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

  2. Changes in hyperfrontality of cerebral blood flow and carbon dioxide reactivity with age

    International Nuclear Information System (INIS)

    We evaluated the topographic distributions of regional cerebral blood flow in 51 normal subjects (mean age 41 years) by the xenon-133 inhalation technique. Forty-five of these subjects were divided by age into young normals less than 30 years old (mean age 24 years), middle-aged normals 30-50 years old (mean age 40 years), and elderly normals greater than 50 years old (mean age 62 years); there were 15 subjects in each group. The distributions of vascular CO2 reactivity to hypocapnia were also evaluated in 20 of the normal subjects (mean age 34 years), including 11 younger normals less than 30 years old (mean age 24 years) and nine older (middle-aged or elderly) normals greater than or equal to 30 years old (mean age 45 years). The hyperfrontal distribution of regional cerebral blood flow observed in the young and middle-aged normals was not observed in the elderly normals. The hyperfrontal distribution of vascular CO2 reactivity observed in the younger normals was absent in the older normals. In addition, the correlation between regional cerebral blood flow and vascular CO2 reactivity observed in the younger normals was disturbed in the older normals. The data show a hyperfrontal distribution of regional cerebral blood flow in normal subjects that diminishes during the fifth and sixth decades, along with a distribution of vascular CO2 reactivity in younger normal subjects that is not homogeneous throughout the frontoparietal regions

  3. Regional cerebral blood flow alterations remote from the site of intracranial tumors

    DEFF Research Database (Denmark)

    Endo, H; Larsen, B; Lassen, N A

    1977-01-01

    Regional cerebral blood flow (rCBF) was investigated in 12 patients with brain tumors, using a 254-channel dynamic gamma camera. In nine of the 12 cases, hyperemic regions with loss of autoregulation were seen in sites remote from the tumor (the area around the tumor was in most cases also...

  4. Sensitivity Analysis of Simulated Blood Flow in Cerebral Aneurysms

    OpenAIRE

    2011-01-01

    Bakgrunn: En cerebral aneurysme er en dilatasjon av en blodåre, som kan utvide seg og briste, og derved forårsake blødninger i og rundt hjernen. En slik tilstand er alvorlig og medfører ofte alvorlig hjerneskade eller død. For å bedre forstå hvorfor enkelte aneurysmer utvikler seg og brister, gjør man datasimuleringer av blodstrømningen i disse aneurysmene for å få en økt forståelse, og på sikt bidra til diagnoser og behandlingsmetoder. Slike simuleringer fører med seg mange usikkerhetsmoment...

  5. The efficiency of laser radiation absorption by hemoglobin and oxyhemoglobin in the skin blood vessels

    International Nuclear Information System (INIS)

    The results of the investigation of the efficiency of light absorption by oxyhemoglobin (HbO2) and deoxyhemoglobin (Hb) in cutaneous blood vessels in dependence on the radiation wavelength and the optical properties of the tissue is presented. Using the Kubelka - Munk optical model of the tissue the spectral dependence of the efficiency of laser interaction both on HbO2 and Hb of blood vessels at different depths of the tissue layer are calculated. The obtained results show that for blood vessels located in tissue up to a depth of 2500 μm the efficiency of laser radiation absorption follows the shape of the Q -absorption bands of HbO2 and Hb

  6. Comparative evaluation of cerebral blood volume and cerebral blood flow in acute ischemic stroke by using perfusion-weighted MR imaging and SPECT

    International Nuclear Information System (INIS)

    Purpose: To investigate the relationship between relative cerebral blood volume (CBV) measured with perfusion-weighted (PW) MR imaging and relative cerebral blood flow (CBF) measured with SPECT in acute ischemic stroke. Material and Methods: Fifteen patients who had acute unilateral middle cerebral artery occlusion underwent both PW MR imaging and 99mTc-HMPAO SPECT with an interval less than 20 minutes between the two examinations within 6 hours after stroke onset. Lesion-to-contralateral relative CBV and CBF ratios measured in multiple regions of interest were compared to evaluate the relationship of the two parameters. Results: An overall linear relationship was found between relative CBV and relative CBF ratios (R2=0.54, p0.05). Regions with evolving infarction had more severe hypoperfusion (mean relative CBF ratio, 0.38±0.22) than regions without (mean relative CBF ratio, 0.70±0.13) (p<0.0001). Conclusion: A significant linear relationship existed between relative CBV and relative CBF in acute ischemic stroke, although relative CBV did not change linearly to relative CBF in mild hypoperfusion. Relative CBV can be used as an alternative to relative CBF within 6 hours after stroke onset, particularly in regions with severe hypoperfusion proceeding to infarction

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

    Science.gov (United States)

    Nilsson, B; Siesjö, B K

    1983-01-01

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

  8. Regional cerebral blood flow abnormalities detected with N-isopropyl-I-123-p-iodoamphetamine in patients with cerebral infarction

    International Nuclear Information System (INIS)

    Single photon emission computed tomography of the brain using N-isopropyl-I-123-p-iodoamphetamine (IMP-SPECT) was performed in 25 patients with cerebral infarction (33 lesions) to determine the value of IMP-SPECT in detecting alteration in regional cerebral blood flow. The interval between the onset of symptom and IMP-SPECT ranged seven hours to eight months. X-CT was performed within a few days of IMP-SPECT. Perfusion deficit detected by IMP-SPECT was larger than the low dencity area seen on X-CT in half of lesions. Six out of 16 lesions less than 2 cm in size on X-CT were demonstrated on IMP-SPECT. Those that went undetected on IMP-SPECT were located deeply; the caudate nucleus, thalamus, putamen and paraventricular region. IMP-SPECT demonstrated perfusion deficit as early as seven hours after the ictus when X-CT remained normal. Crossed cerebellar diaschisis was observed in one third of cases. It is concluded that IMP-SPECT surpasses X-CT in making early detection of cerebral infarction with exeption of basal ganglionic lesion less than 2 cm in size. (author)

  9. Adequate cutoff frequency of the prefilter in quantification of regional cerebral blood flow using 123I-IMP

    International Nuclear Information System (INIS)

    The effect of cutoff frequency (CF) of the butterworth filter was studied in the quantification of regional cerebral blood flow (rCBF) by N-isopropyl-P-[123I]-iodoamphetamine (123I-IMP) auto-radiography (ARG) to determine the adequate cutoff value by comparison with XeCT/CBF. The single photon emission computed tomography (SPECT) machine was Toshiba 3-detector GCA-9300A/PI equipped with a low energy high resolution fanbeam collimator and data processor GMS-5500A/PI, on which the butterworth filter was loaded. SPECT data acquisition was performed 18-48 min after 123I-IMP injection, and the data and blood radioactivity at 10 min measured by Aloka auto-well counter ARC-300 were used for calculating rCBF (ARG/CBF) values. The CCP-II phantom for the cross calibration factor (CCF) was purchased from Sangyo Kagaku Co., Ltd. and was filled with 123I-IMP (10 kBq/mL). The CT machine was Toshiba X-vigor, and CT with Xenon gas (XeCT) was done with the products of Anzai Sogyo aspirator AZ-725 and data processor AZ-7000. XeCT data acquisition was performed by 4 min aspiration/4 min washout of the gas (Xe 30%, O2 70%) and XeCT/CBF values were calculated with the processor AZ-7000. Data were selected from 80 patients (M 46, average age 62.1 y) with chronic diseases of cerebral blood vessels, in whom ARG/CBF and XeCT/CBF tests had been conducted within a week. Examined were the relationships between CF (0.523-0.930 cycles/cm) vs CCF; CF vs ARG/CBF, where rCBF was defined to be at regions of the middle cerebral artery, thalamus and cerebral ventricle; ARG/CBF vs XeCT/CBF at CF of 0.581-0.930, where the correlation coefficient (r) and slope were evaluated for decision of the optimal CF value. Under conditions employed, CBF values varied with the CF and its optimal value was found to be 0.814 cycles/cm with a best fitted slope. (T.T.)

  10. Mathematical modelling for trajectories of magnetic nanoparticles in a blood vessel under magnetic field

    International Nuclear Information System (INIS)

    A mathematical model is developed to describe the trajectories of a cluster of magnetic nanoparticles in a blood vessel for the application of magnetic drug targeting (MDT). The magnetic nanoparticles are injected into a blood vessel upstream from a malignant tissue and are captured at the tumour site with help of an applied magnetic field. The applied field is produced by a rare earth cylindrical magnet positioned outside the body. All forces expected to significantly affect the transport of nanoparticles were incorporated, including magnetization force, drag force and buoyancy force. The results show that particles are slow down and captured under the influence of magnetic force, which is responsible to attract the magnetic particles towards the magnet. It is optimized that all particles are captured either before or at the centre of the magnet (z≤0) when blood vessel is very close proximity to the magnet (d=2.5 cm). However, as the distance between blood vessel and magnet (d) increases (above 4.5 cm), the magnetic nanoparticles particles become free and they flow away down the blood vessel. Further, the present model results are validated by the simulations performed using the finite element based COMSOL software. - Highlights: • A mathematical model is developed to describe the trajectories of magnetic nanoparticles. • The dominant magnetic, drag and buoyancy forces are considered. • All particles are captured when distance between blood vessel and magnet (d) is up to 4.5 cm. • Further increase in d value (above 4.5 cm) results the free movement of magnetic particles

  11. Do haematophagous bugs assess skin surface temperature to detect blood vessels?

    Directory of Open Access Journals (Sweden)

    Raquel A Ferreira

    Full Text Available BACKGROUND: It is known that some blood-sucking insects have the ability to reach vessels under the host skin with their mouthparts to feed blood from inside them. However, the process by which they locate these vessels remains largely unknown. Less than 5% of the skin is occupied by blood vessels and thus, it is not likely that insects rely on a "random search strategy", since it would increase the probability of being killed by their hosts. Indeed, heterogeneities along the skin surface might offer exploitable information for guiding insect's bites. METHODOLOGY/PRINCIPAL FINDINGS: We tested whether the bug Rhodnius prolixus can evaluate temperature discontinuities along the body surface in order to locate vessels before piercing the host skin. When placed over a rabbit ear, the bug's first bites were mostly directed towards the main vessels. When insects were confronted to artificial linear heat sources presenting a temperature gradient against the background, most bites were directly addressed to the warmer linear source, notwithstanding the temperature of both, the source and the background. Finally, tests performed using uni- and bilaterally antennectomized insects revealed that the bilateral integration of thermal inputs from both antennae is necessary for precisely directing bites. CONCLUSIONS/SIGNIFICANCE: R. prolixus may be able to exploit the temperature differences observed over the skin surface to locate blood vessles. Bugs bite the warmest targets regardless of the target/background temperatures, suggesting that they do not bite choosing a preferred temperature, but select temperature discontinuities along the skin. This strategy seems to be an efficient one for finding blood vessels within a wide temperature range, allowing finding them on different hosts, as well as on different areas of the host body. Our study also adds new insight about the use of antennal thermal inputs by blood sucking bugs.

  12. Mathematical modelling for trajectories of magnetic nanoparticles in a blood vessel under magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Shashi, E-mail: shashisharma1984@gmail.com; Katiyar, V.K.; Singh, Uaday

    2015-04-01

    A mathematical model is developed to describe the trajectories of a cluster of magnetic nanoparticles in a blood vessel for the application of magnetic drug targeting (MDT). The magnetic nanoparticles are injected into a blood vessel upstream from a malignant tissue and are captured at the tumour site with help of an applied magnetic field. The applied field is produced by a rare earth cylindrical magnet positioned outside the body. All forces expected to significantly affect the transport of nanoparticles were incorporated, including magnetization force, drag force and buoyancy force. The results show that particles are slow down and captured under the influence of magnetic force, which is responsible to attract the magnetic particles towards the magnet. It is optimized that all particles are captured either before or at the centre of the magnet (z≤0) when blood vessel is very close proximity to the magnet (d=2.5 cm). However, as the distance between blood vessel and magnet (d) increases (above 4.5 cm), the magnetic nanoparticles particles become free and they flow away down the blood vessel. Further, the present model results are validated by the simulations performed using the finite element based COMSOL software. - Highlights: • A mathematical model is developed to describe the trajectories of magnetic nanoparticles. • The dominant magnetic, drag and buoyancy forces are considered. • All particles are captured when distance between blood vessel and magnet (d) is up to 4.5 cm. • Further increase in d value (above 4.5 cm) results the free movement of magnetic particles.

  13. Transient Non-Newtonian Blood Flow under Magnetic Targeting Drug Delivery in an Aneurysm Blood Vessel with Porous Walls

    Science.gov (United States)

    Alimohamadi, Haleh; Imani, Mohsen

    2014-11-01

    The present investigation deals with numerical solution of blood flow patterns through an aneurysm artery under the applied magnetic field. Transient extended Navier-Stokes, Brinkman, continuity, and heat conduction equations govern this phenomenon and unsteady pulsatile inlet velocity varies by human heart-beating frequency. Our simulation demonstrates applying 105 magnetic field intensity (MnF) to recirculate flow and increase fluid flux and maximum blood temperature by 62.5x and 3.5%, respectively, in the aneurysm region. It is also shown that the vessel's wall porosity plays an important role in magnetic targeting of drug delivery performance, as this parameter can noticeably change maximum blood temperature and pressure.

  14. Instability of the middle cerebral artery blood flow in response to CO2.

    Directory of Open Access Journals (Sweden)

    Rosemary E Regan

    Full Text Available BACKGROUND: The middle cerebral artery supplies long end-artery branches to perfuse the deep white matter and shorter peripheral branches to perfuse cortical and subcortical tissues. A generalized vasodilatory stimulus such as carbon dioxide not only results in an increase in flow to these various tissue beds but also redistribution among them. We employed a fast step increase in carbon dioxide to detect the dynamics of the cerebral blood flow response. METHODOLOGY/PRINCIPAL FINDINGS: The study was approved by the Research Ethics Board of the University Health Network at the University of Toronto. We used transcranial ultrasound to measure the time course of middle cerebral artery blood flow velocity in 28 healthy adults. Normoxic, isoxic step increases in arterial carbon dioxide tension of 10 mmHg from both hypocapnic and normocapnic baselines were produced using a new prospective targeting system that enabled a more rapid step change than has been previously achievable. In most of the 28 subjects the responses at both carbon dioxide ranges were characterised by more complex responses than a single exponential rise. Most responses were characterised by a fast initial response which then declined rapidly to a nadir, followed by a slower secondary response, with some showing oscillations before stabilising. CONCLUSIONS/SIGNIFICANCE: A rapid step increase in carbon dioxide tension is capable of inducing instability in the cerebral blood flow control system. These dynamic aspects of the cerebral blood flow responses to rapid changes in carbon dioxide must be taken into account when using transcranial blood flow velocity in a single artery segment to measure cerebrovascular reactivity.

  15. Inclusion body myositis, muscle blood vessel and cardiac amyloidosis, and transthyretin Val122Ile allele.

    Science.gov (United States)

    Askanas, V; Engel, W K; Alvarez, R B; Frangione, B; Ghiso, J; Vidal, R

    2000-04-01

    Typical of sporadic inclusion body myositis muscle biopsies are vacuolated muscle fibers containing intracellular amyloid deposits and accumulations of "Alzheimer-characteristic" proteins. There is no muscle blood vessel or cardiac amyloidosis. We report on a 70-year-old African-American man homozygous for the transthyretin Val122Ile allele who has both sporadic inclusion body myositis and cardiac amyloidosis. His unique pathological features included transthyretin immunoreactivity in prominent muscle blood vessel amyloid and congophilic amyloid deposits within vacuolated muscle fibers. PMID:10762172

  16. Negative Pressure Wound Therapy - Mechanisms of Action and Protecting Exposed Blood Vessels in the Wound Bed

    OpenAIRE

    Anesäter, Erik

    2015-01-01

    NPWT has recently been associated with severe complications and bleeding when used in wounds with exposed blood vessels. The aims of this work were to investigate the mechanisms of action of NPWT and to explore the possibility of using thin plastic discs to protect exposed blood vessels in the wound bed during NPWT. Three different kinds of wounds were created in pigs: 6 cm and 10 cm diameter circular defect wounds on the back and 6 cm incision wounds in the groin, exposing the...

  17. How to explore the effects of sex hormone on blood vessels

    Institute of Scientific and Technical Information of China (English)

    Sun Mei-li; Nie Min; Liu Bing; Du Zhi-jun; Ge Qin-sheng

    2004-01-01

    The risk of cardiovascular disease increases along with aging. There are increasing interests in researches on the protective effects of hormone replacement therapy (HRT)on cardiovascular system in postmenopausal women. In this article we will review how we have explored the evidence of different sex hormones on blood vessels since 1996. The results showed that low-dose HRT significantly protected cardiovascular system in postmenopausal women.However, the high-dose 17β-estradiol (E2), with or without progesterone (P) or testosterone (T), or any hormone alone, as their concentrations increase, may even inhibit the protective effects of low-dose HRT on blood vessels.

  18. Effect of Rolling Massage on the Vortex Flow in Blood Vessels with Lattice Boltzmann Simulation

    Science.gov (United States)

    Yi, Hou Hui

    The rolling massage manipulation is a classic Chinese Medical Massage, which is a nature therapy in eliminating many diseases. Here, the effect of the rolling massage on the cavity flows in blood vessel under the rolling manipulation is studied by the lattice Boltzmann simulation. The simulation results show that the vortex flows are fully disturbed by the rolling massage. The flow behavior depends on the rolling velocity and the rolling depth. Rolling massage has a better effect on the flows in the cavity than that of the flows in a planar blood vessel. The result is helpful to understand the mechanism of the massage and develop the rolling techniques.

  19. Disodium cromoglycate, a mast-cell stabilizer, alters postradiation regional cerebral blood flow in primates

    Energy Technology Data Exchange (ETDEWEB)

    Cockerham, L.G.; Doyle, T.F.; Pautler, E.L.; Hampton, J.D.

    1986-01-01

    Early transient incapacitation (ETI) is the complete cessation of performance during the first 30 min after radiation exposure, and performance decrement (PD) is a reduction in performance at the same time. Supralethal doses of radiation have been shown to produce a marked decrease in regional cerebral blood flow in primates concurrent with systemic hypotension and a dramatic release of mast-cell histamine. In an attempt to elucidate mechanisms underlying the radiation-induced ETI/PD phenomena and the postradiation decrease in cerebral blood flow, primates were given the mast-cell stabilizers disodium cromoglycate (DSCG) or BRL 22321 before exposure to 100 Gy whole-body gamma radiation. Hypothalamic and cortical blood flows were measured by hydrogen clearance, before and after radiation exposure. Systemic blood pressures were determined simultaneously. The data indicated that DSCG was successful in diminishing postradiation decrease in cerebral blood flow. Irradiated animals pretreated with DSCG, showed only a 10% decrease in hypothalamic blood flow 60 min postradiation, while untreated, irradiated animals showed a 57% decrease. The cortical blood flow of DSCG treated, irradiated animals showed a triphasic response, with a decrease of 38% at 10 min postradiation, then a rise to 1% below baseline at 20 min, followed by a fall to 42% below baseline by 50 min postradiation. In contrast, the untreated, irradiated animals showed a steady decrease in cortical blood flow to 79% below baseline by 50 min postradiation. There was no significant difference in blood-pressure response between the treated and untreated, irradiated animals. Systemic blood pressure showed a 60% decrease at 10 min postradiation, falling to a 71% decrease by 60 min.

  20. Effect of Korea red ginseng on cerebral blood flow and superoxide production

    Institute of Scientific and Technical Information of China (English)

    Cuk Seong KIM; Jin Bong PARK; Kwang-Jin KIM; Seok Jong CHANG; Sung-Woo RYOO; Byeong Hwa JEON

    2002-01-01

    AIM: To investigate the effects of Korea red ginseng (KRG) on the cerebral perfusion rate in the rats and the generation of superoxide anion in the endothelial cells. METHODS: The cerebral perfusion rate was measured using laser-doppler flowmetry before and after the administration of crude saponin (CS) and saponin-free fraction (SFF) of KRG in the anesthetized rats. The superoxide generation was measured by the method based on lucigeninenhanced chemiluminescence in the cultured endothelial cells. RESULTS: The relative cerebral perfusion rate (rCBF) was significantly increased by the intraperitoneal injection of CS (100 mg/kg) in the rats, but SFF had no effect on the rCBF. Chronic treatment with CS for 7 d significantly inhibited the decrease of forebrain cerebral blood flow induced by clamping both carotid arteries in the rats. Furthermore, CS (0.1 g/L) significantly suppressed NADPH-induced superoxide generation in the human umbilical vein endothelial cells (P<0.01).CONCLUSION: The present study demonstrated that crude saponin fraction of KRG enhanced cerebral blood flow in rats. Furthermore, crude saponin fraction of KRG abrogated the NADPH-driven superoxide generation in endothelial cells.

  1. Postmortem computed tomography with the use of air for blood vessel enhancement-Early experience.

    Science.gov (United States)

    Borowska-Solonynko, Aleksandra; Solonynko, Bohdan; Fudalej, Marcin; Żyłkowski, Jarosław

    2016-04-01

    Postmortem computed tomography (PMCT) is gaining popularity in forensic medicine. Computed tomography routinely performed in clinical medicine involves intravenous contrast administration. Unfortunately, postmortem examinations are typically limited to uncontrasted CT scans, where blood vessels and their potential injury sites are invisible. One serious problem is the fact that due to the process of decomposition, contrast agents used for vessel visualization in the living cannot be used in cadavers. Therefore, a special contrast agent designed for cadavers has been developed. This contrast agent has a high density and is lipophilic. Its use ensures very good visualization of blood vessels it is, however, associated with high costs and may alter findings of a later histopathological examination. This study presents early experience with the air as negative contrast agent to enhance all blood vessels in the body. The carbon dioxide (CO2) gas has been used as a contrast agent in live individuals with contraindications against the use of iodinated contrast. In corpses with advanced postmortem changes, putrefaction gases also considerably enhance the visibility of blood vessels and organs they fill. There have also been some positive effects with the use of gas in postmortem angiography of coronary vessels. These findings encouraged us to attempt air administration via catheters introduced into the femoral artery or a central venous access site in the superior vena cava. The gas distributed easily throughout the body and surprisingly well contrasted both arteries and veins of various caliber. The presence of the air administered into vessels did not cause any apparent, significant alterations in autopsy findings. Although optimization of the gas administration technique requires further studies, we can already say that this is a promising direction in postmortem angiography. PMID:26921814

  2. A study on regional cerebral blood flow measurement by 133FXe inhalation method

    International Nuclear Information System (INIS)

    Fundamental and clinical investigations were performed on reliability of Fourier analysis of head clearance curves in regional cerebral blood flow measurement by 133Xe inhalation methods as compared with conventional Obrist analysis. Fourier analysis revealed better reproducibilities determined by computer simulated curves and repetitive measurements in man than Obrist analysis. In the studies of the changes of regional cerebral blood flow from the resting conditions to the conditions of finger movement, listening to verbal material or music and reading aloud in right-handed normal subjects, both F1 (a flow of the fast component of two compartmental model) and ISI (Initial Slope Index: calculated from the initial slope of the wash out curves corrected for recirculation) of Fourier analysis were more sensitive to detect significant changes than Obrist analysis. On the basis of the fact mentioned above, it was concluded that ISI of Fourier analysis was the best index of regional cerebral blood flow. Age-matched normal values of ISI of Fourier analysis were calculated from 132 measurements in 105 normal right-handed subjects, aged 19 to 80 years old (mean 42 years). Mean brain ISI showed significant negative correlation with advancing age (r = -0.70, p < 0.001). The regression line and 95% confidence interval were Y = -0.32X + 69.6 and +- 11.2, respectively. In comparison with the measured values of the patients with cerebrovascular disorders, this age-matched normal values were proved to be sufficient for practical use. Regional ISI also showed significant negative correlations with advancing age in the entire brain (p < 0.001). The regional reduction of ISI with advancing age was significantly greater in the regional distribution of the middle cerebral arteries bilaterally, compared with regions in the distributions of either the anterior cerebral, the posterior cerebral or vertebrobasilar arteries (p < 0.05). (J.P.N.)

  3. Cerebral extraction of N-13 ammonia: its dependence on cerebral blood flow and capillary permeability, surface area product

    International Nuclear Information System (INIS)

    13N-labeled ammonia was used to investigate: (1) the cerebral extraction and clearance of ammonia; (2) the mechanicsm by which capillaries accommodate changes in cerebral blood flow (CBF); and (3) its use for the measure of CBF. This was investigated by measuring the single pass extraction of 13NH3 in rhesus monkeys during P/sub a/CO2 induced changes in CBF, and with dog studies using in vitro tissue counting techniques to examine 13NH3 extraction in gray and white matter, mixed tissue, and cerebellum during variations in CBF produced by combinations of embolization, local brain compression, and changes in P/sub a/CO2. The single pass extraction fraction of 13NH3 varied from about 70 to 20% over a CBF range of 12 to 140cc/min/100gms. Capillary permeability-surface area product (PS) estimates from this data and the dog experiments show PS increasing with CBF. The magnitude and rate of increase in PS with CBF was highest in gray matter > mixed tissue > white matter. Tissue extraction of 13NH3 vs CBF relationship was best described by a unidirectional transport model in which CBF increases by both recruitment of capillaries and by increases of blood velocity in open capillaries. Glutamine synthetase, which incorporates 13NH3 into glutamine, appears to be anatomically located in astrocytes in general and specifically in the astrocytic pericapillary end-feet that are in direct contact with gray and white matter capillaries. The net 13NH3 extraction subsequent to an i.v. injection increases nonlinearly with CBF. Doubling or halving basal CBF produced from 40 to 50% changes in the 13N tissue concentrations with further increases in CBF associated with progressively smaller changes in 13N concentrations. 13NH3 appears to be a good tracer for the detection of cerebral ischemia with positron tomography but exhibits a poor response at high values of CBF

  4. Model estimation of cerebral hemodynamics between blood flow and volume changes: a data-based modelling approach

    OpenAIRE

    Wei, H L; Zheng, Y; Pan, Y.; Coca, D.; Li, L M; Mayhew, J.E.W.; S. A. Billings

    2008-01-01

    It is well known that there is a dynamic relationship between cerebral blood flow (CBF) and cerebral blood volume (CBV). With increasing applications of functional magnetic resonance imaging (fMRI), where the blood oxygen level dependent (BOLD) signals are recorded, the understanding and accurate modelling of the hemodynamic relationship between CBF and CBV becomes increasingly important. This study presents an empirical and data-based modelling framework for model identification from CBF and...

  5. Mouse lung contains endothelial progenitors with high capacity to form blood and lymphatic vessels

    Directory of Open Access Journals (Sweden)

    Barleon Bernhard

    2010-07-01

    Full Text Available Abstract Background Postnatal endothelial progenitor cells (EPCs have been successfully isolated from whole bone marrow, blood and the walls of conduit vessels. They can, therefore, be classified into circulating and resident progenitor cells. The differentiation capacity of resident lung endothelial progenitor cells from mouse has not been evaluated. Results In an attempt to isolate differentiated mature endothelial cells from mouse lung we found that the lung contains EPCs with a high vasculogenic capacity and capability of de novo vasculogenesis for blood and lymph vessels. Mouse lung microvascular endothelial cells (MLMVECs were isolated by selection of CD31+ cells. Whereas the majority of the CD31+ cells did not divide, some scattered cells started to proliferate giving rise to large colonies (> 3000 cells/colony. These highly dividing cells possess the capacity to integrate into various types of vessels including blood and lymph vessels unveiling the existence of local microvascular endothelial progenitor cells (LMEPCs in adult mouse lung. EPCs could be amplified > passage 30 and still expressed panendothelial markers as well as the progenitor cell antigens, but not antigens for immune cells and hematopoietic stem cells. A high percentage of these cells are also positive for Lyve1, Prox1, podoplanin and VEGFR-3 indicating that a considerabe fraction of the cells are committed to develop lymphatic endothelium. Clonogenic highly proliferating cells from limiting dilution assays were also bipotent. Combined in vitro and in vivo spheroid and matrigel assays revealed that these EPCs exhibit vasculogenic capacity by forming functional blood and lymph vessels. Conclusion The lung contains large numbers of EPCs that display commitment for both types of vessels, suggesting that lung blood and lymphatic endothelial cells are derived from a single progenitor cell.

  6. Contact-inhibited chemotaxis in de novo and sprouting blood-vessel growth.

    Directory of Open Access Journals (Sweden)

    Roeland M H Merks

    Full Text Available Blood vessels form either when dispersed endothelial cells (the cells lining the inner walls of fully formed blood vessels organize into a vessel network (vasculogenesis, or by sprouting or splitting of existing blood vessels (angiogenesis. Although they are closely related biologically, no current model explains both phenomena with a single biophysical mechanism. Most computational models describe sprouting at the level of the blood vessel, ignoring how cell behavior drives branch splitting during sprouting. We present a cell-based, Glazier-Graner-Hogeweg model (also called Cellular Potts Model simulation of the initial patterning before the vascular cords form lumens, based on plausible behaviors of endothelial cells. The endothelial cells secrete a chemoattractant, which attracts other endothelial cells. As in the classic Keller-Segel model, chemotaxis by itself causes cells to aggregate into isolated clusters. However, including experimentally observed VE-cadherin-mediated contact inhibition of chemotaxis in the simulation causes randomly distributed cells to organize into networks and cell aggregates to sprout, reproducing aspects of both de novo and sprouting blood-vessel growth. We discuss two branching instabilities responsible for our results. Cells at the surfaces of cell clusters attempting to migrate to the centers of the clusters produce a buckling instability. In a model variant that eliminates the surface-normal force, a dissipative mechanism drives sprouting, with the secreted chemical acting both as a chemoattractant and as an inhibitor of pseudopod extension. Both mechanisms would also apply if force transmission through the extracellular matrix rather than chemical signaling mediated cell-cell interactions. The branching instabilities responsible for our results, which result from contact inhibition of chemotaxis, are both generic developmental mechanisms and interesting examples of unusual patterning instabilities.

  7. Local cerebral blood flow and glucose metabolism during seizure in spontaneously epileptic El mice

    International Nuclear Information System (INIS)

    Local cerebral blood flow and glucose metabolism were examined in spontaneously epileptic El mice using autoradiography with 125I-IMP and 14C-DG in the interictal phase and during seizure. El (+) mice that developed generalized tonic-clonic convulsions and El (-) mice that received no stimulation and had no history of epileptic seizures were examined. The seizure non-susceptible, maternal strain ddY mice were used as control. Uptake ratios for IMP and DG in mouse brain were calculated using the autoradiographic density. In the interictal phase, the pattern of local cerebral blood flow of El (+) mice was similar to that of ddY and El (-) mice, and glucose metabolism in the hippocampus was higher in El (+) mice than in El (-) and ddY mice, but flow and metabolism were nearly matched. During seizure, no significant changed blood flow and increased glucose metabolism in the hippocampus, the epileptic focus, and no markedly changed blood flow and depressed glucose metabolism in other brain regions were observed and considered to be flow-metabolism uncoupling. These observations have never been reported in clinical or experimental studies of epilepsy. Seizures did not cause large regional differences in cerebral blood flow. Therefore, only glucose metabolism is useful for detection of the focus of secondary generalized seizures in El mice, and appeared possibly to be related to the pathophysiology of secondary generalized epilepsy in El mice. (author)

  8. Cerebral blood volume measured using near-infrared spectroscopy and radiolabels in the immature lamb brain.

    Science.gov (United States)

    Barfield, C P; Yu, V Y; Noma, O; Kukita, J; Cussen, L J; Oates, A; Walker, A M

    1999-07-01

    Near-infrared spectroscopy (NIRS) is a technique that is increasingly being used for the noninvasive measurement of cerebral blood volume (CBV) in newborn infants, but it has not been fully validated against established methods. These experiments in immature lambs (gestation 92+/-1 d, mean+/-SEM) compared CBV measured using NIRS-derived estimates of oxygenated Hb (n = 5) with CBV estimated with radiolabeled indicators (125I-labeled serum albumin and 51Cr-labeled red blood cells, n = 10). Total brain CBV (mL/100 g tissue) measured using NIRS was 2.5+/-0.2 compared with 2.5+/-0.2 using radiolabels (NS). Regional tissue plasma, red blood cells, and whole blood volumes from radiolabels varied significantly (p cerebellum > cortex > brain stem = midbrain > white matter. Regional plasma and red blood cell distributions were similar to whole blood, being highest in choroid plexus (13.0+/-1.6 and 3.2+/-0.9, respectively), and least in white matter (0.8+/-0.1 and 0, respectively). These data from the immature lamb brain indicate that total CBV measured with NIRS is essentially identical with the volumes obtained using intravascular radiolabels. Among cerebral regions, white matter contributes little to the global blood volume measured with NIRS because its red blood cell content is very low. PMID:10400134

  9. Evaluation of regional cerebral blood flow with ECD in persons using basic cocaine paste

    International Nuclear Information System (INIS)

    Basic cocaine paste is an unrefined derivative of the coca leaf in which a high content of toxic elements is associated with the alkaloid. Owing to its low cost and the fact that it is easy to obtain, basic cocaine paste is the most commonly used drug in Peru, in particular among young people and the poorer social classes. The aim was to attempt to detect and substantiate possible toxic effects of basic cocaine paste on the brain by evaluating alterations in regional cerebral blood flow in chronic consumers of this drug. To this end, two groups of ten patients were selected. The first group (A) comprised people who did not take the drug and the second group (B) comprised chronic consumers of basic cocaine paste. Regional cerebral blood flow studies employing 99Tcm-ECD (ethyl cysteinate dimer) were performed on both groups using a single photon emission computed tomography (SPECT) type gamma camera. A qualitative and quantitative analysis of the data was carried out to evaluate the asymmetries and the distribution of the tracer in the brain. The results show a clear alteration in cerebral perfusion in the majority (80%) of consumers of basic cocaine paste, indicating that these patients should be monitored in order to evaluate whether the alterations in regional cerebral blood flow revert to normal when consumption of the drug ceases. (author). 11 refs

  10. Effect of stimulation of trigeminal ganglion on regional cerebral blood flow in cats

    International Nuclear Information System (INIS)

    Regional cerebral blood flow was studied in the cat, with and without trigeminal ganglion stimulation, by the intravenous injection of the tracer [14C]iodoantipyrine and subsequent regional brain dissection. Electrical activation of the trigeminal ganglion led to a selective increase in regional blood flow in the frontal and parietal cortex that was bilateral without change in the posterior cortex, deep cerebral nuclei, white matter, or brain stem. Unilateral intracranial section of the facial nerve blocked the response in the ipsilateral frontal and parietal cortex, whereas bilateral facial nerve section blocked the contralateral frontal cortical response. The contralateral parietal cortical increase in blood flow was not affected by facial nerve section and may thus represent the result of metabolic activation of sensory cortex

  11. Chronically impaired autoregulation of cerebral blood flow in long-term diabetics

    DEFF Research Database (Denmark)

    Bentsen, N; Larsen, B; Lassen, N A

    1975-01-01

    Using the arteriovenous oxygen difference method autoregulation of cerebral blood flow (CBF) was tested in 16 long-term diabetics and eight control patients. Blood pressure was raised by angiotensin infusion and lowered by trimethaphan camsylate infusion, in some cases combined with head-up tilting...... of the patient. Regression analysis was carried out on the results in order to quantify autoregulatory capacity. In the control patients CBF did not vary with moderate blood pressure variations, indicating normal autoregulation. In four of the 16 diabetic patients CBF showed significant pressure...... dependency, indicating impaired autoregulation. The cause of impaired autoregulation in some long-term diabetics is believed to be diffuse or multifocal dysfunction of cerebral arterioles due to diabetic vascular disease. Other conditions with impaired autoregulation are discussed and compared with that seen...

  12. Peristaltic Pumping of Blood Through Small Vessels of Varying Cross-Section

    Science.gov (United States)

    Misra, J. C.; Maiti, S.

    2012-11-01

    The paper is devoted to a study of the peristaltic motion of blood in the micro-circulatory system. The vessel is considered to be of varying cross-section. The progressive peristaltic waves are taken to be of sinusoidal nature. Blood is considered to be a Herschel-Bulkley fluid. Of particular concern here is to investigate the effects of amplitude ratio, mean pressure gradient, yield stress and the power law index on the velocity distribution, streamline pattern and wall shear stress. On the basis of the derived analytical expression, extensive numerical calculations have been made. The study reveals that velocity of blood and wall shear stress are appreciably affected due to the non-uniform geometry of blood vessels. They are also highly sensitive to the magnitude of the amplitude ratio and the value of the fluid index.

  13. Effects of long-term administration of Cilostazol on chronic cerebral circulatory insufficiency. With special reference to cerebral blood flow and clinical symptoms

    International Nuclear Information System (INIS)

    This report deals with a study of the effectiveness, safety, and usefulness of long-term administration of Cilostazol for the improvement of cerebral blood flow and clinical symptoms in 24 patients with Chronic Cerebral Circulatory Insufficiency. Cerebral blood flow was investigated quantitatively using the Patlak plot method. Cilostazol was orally administered for 209 days on average. In the global improvement rating assessed on the basis of all subjective symptoms, the final improvement rate, comprising all cases showing moderate or better improvement, was 52.2%. Regarding individual symptoms, dizziness, orthostatic syncope, dull headache, and headache showed improvement rates of 30% or more. Regional cerebral blood flow (rCBF) was increased in both cerebral and cerebellar hemispheres. The global improvement rating for subjective symptoms and the Δ%rCBF for every region except the cerebral hemispheres were positively correlated. However, there was no positive correlation between the global improvement rating for psychiatric symptoms and the Δ%rCBF for any region. Regarding individual subjective symptoms, dizziness showed an especially high positive correlation of above 0.7 between the improvement rating and the Δ%rCBF in the left temporal lobe, basal ganglia, and cerebellum. Headache was observed as an adverse drug reaction in 8 of 24 patients, but it disappeared with reduction of the dose or discontinuation of administration. No other severe adverse drug reactions were noticed. In summary, it was concluded that Cilostazol was useful for treating chronic cerebral circulatory insufficiency. (author)

  14. Do double gloves protect against contamination during cannulation of blood vessels? A prospective randomized study

    OpenAIRE

    Łukasz Szarpak; Andrzej Kurowski

    2014-01-01

    Background: Undamaged medical gloves protect medical personnel from contact with physiological fluids of the patient. Thus they protect the assistance provider from hand skin contamination with potentially infectious biological material. The aim of the study was to evaluate the occurrence of pierce, perforations or damage of medical gloves during cannulation of blood vessels. Materials and Methods: In the prospective randomized study 303 pairs of gloves, used during cannulation of blood vesse...

  15. Modeling blood flow in vessels with changeable caliber for physiology and biophysics courses.

    Science.gov (United States)

    Kozlova, E K; Badicov, V I; Chemysh, A M; Bogushevich, M S

    1997-06-01

    A model based on elementary principles of hydrodynamics and mathematics is proposed for classroom research on concepts related to blood flow physiology. This is an analog model of the vascular system in which blood flow is represented by electrical current flowing in a resistance circuit. The model permits analysis of the change in hemodynamics with local stenosis of both large and peripheral vessels. PMID:9227648

  16. Caffeine and human cerebral blood flow: A positron emission tomography study

    International Nuclear Information System (INIS)

    Positron emission tomography (PET) was used to quantify the effect of caffeine on whole brain and regional cerebral blood flow (CBF) in humans. A mean dose of 250 mg of caffeine produced approximately a 30% decrease in whole brain CBF; regional differences in caffeine effect were not observed. Pre-caffeine CBF strongly influenced the magnitude of the caffeine-induced decrease. Caffeine decreased paCO2 and increased systolic blood pressure significantly; the change in paCO2 did not account for the change in CBF. Smaller increases in diastolic blood pressure, heart rate, plasma epinephrine and norepinephrine, and subjectively reported anxiety were also observed

  17. Impaired autoregulation of cerebral blood flow in the distressed newborn infant

    DEFF Research Database (Denmark)

    Lou, H C; Lassen, N A; Friis-Hansen, B

    1979-01-01

    Cerebral blood flow was measured, using the 133Xe clearance technique, a few hours after birth in 19 infants with varying degrees of respiratory distress syndrome. Ten of these infants had had asphyxia at birth. The least affected infants with normotension (systolic blood pressure 60 to 65 mm Hg......) had CBF values of about 40 ml/100 gm/minute. Hypotensive infants with asphyxia at birth or RDS or both had values for CBF of about 20 ml/100 gm/minute, or less. CBF was strongly correlated with the arterial blood pressure, showing a linear relationship that was identical in infants with asphyxia at...

  18. Spatiotemporal changes in blood-brain barrier permeability, cerebral blood flow, T2 and diffusion following mild traumatic brain injury.

    Science.gov (United States)

    Li, Wei; Watts, Lora; Long, Justin; Zhou, Wei; Shen, Qiang; Jiang, Zhao; Li, Yunxia; Duong, Timothy Q

    2016-09-01

    The blood-brain barrier (BBB) can be impaired following traumatic brain injury (TBI), however the spatiotemporal dynamics of BBB leakage remain incompletely understood. In this study, we evaluated the spatiotemporal evolution of BBB permeability using dynamic contrast-enhanced MRI and measured the volume transfer coefficient (K(trans)), a quantitative measure of contrast agent leakage across the blood and extravascular compartment. Measurements were made in a controlled cortical impact (CCI) model of mild TBI in rats from 1h to 7 days following TBI. The results were compared with cerebral blood flow, T2 and diffusion MRI from the same animal. Spatially, K(trans) changes were localized to superficial cortical layers within a 1mm thickness, which was dramatically different from the changes in cerebral blood flow, T2 and diffusion, which were localized to not only the superficial layers but also to brain regions up to 2.2mm from the cortical surface. Temporally, K(trans) changes peaked at day 3, similar to CBF and ADC changes, but differed from T2 and FA, whose changes peaked on day 2. The pattern of superficial cortical layer localization of K(trans) was consistent with patterns revealed by Evans Blue extravasation. Collectively, these results suggest that BBB disruption, edema formation, blood flow disturbance and diffusion changes are related to different components of the mechanical impact, and may play different roles in determining injury progression and tissue fate processes following TBI. PMID:27208495

  19. Capillary pericytes regulate cerebral blood flow in health and disease

    DEFF Research Database (Denmark)

    Hall, Catherine N; Reynell, Clare; Gesslein, Bodil;

    2014-01-01

    that neuronal activity and the neurotransmitter glutamate evoke the release of messengers that dilate capillaries by actively relaxing pericytes. Dilation is mediated by prostaglandin E2, but requires nitric oxide release to suppress vasoconstricting 20-HETE synthesis. In vivo, when sensory input...... increases blood flow, capillaries dilate before arterioles and are estimated to produce 84% of the blood flow increase. In pathology, ischaemia evokes capillary constriction by pericytes. We show that this is followed by pericyte death in rigor, which may irreversibly constrict capillaries and damage the...

  20. Matrix metalloproteinase-9 expression and blood brain barrier permeability in the rat brain after cerebral ischemia/reperfusion injury

    Institute of Scientific and Technical Information of China (English)

    Lifang Lei; Xiaohong Zi; Qiuyun Tu

    2008-01-01

    BACKGROUND: The integrity of the blood brain barrier (BBB) plays an important role in the patho-physiological process of cerebral ischemia/reperfusion injury. It has been recently observed that metalloproteinase-9 (MMP-9) is closely related to cerebral ischemia/reperfusion injuryOBJECTIVE: This study was designed to observe MMP-9 expression in the rat brain after cerebral ischemia/reperfusion injury and to investigate its correlation to BBB permeability.DESIGN, TIME AND SETTING: This study, a randomized controlled animal experiment, was performed at the Institute of Neurobiology, Central South University between September 2005 and March 2006.MATERIALS: Ninety healthy male SD rats, aged 3-4 months, weighing 200-280g, were used in the present study. Rabbit anti-rat MMP-9 polyclonal antibody (Boster, Wuhan, China) and Evans blue (Sigma, USA) were also used.METHODS: All rats were randomly divided into 9 groups with 10 rats in each group: normal control group, sham-operated group, and ischemia for 2 hours followed by reperfusion for 3,6,12 hours, 1,2,4 and 7 days groups. In the ischemia/reperfusion groups, rats were subjected to ischemia/reperfusion injury by suture occlusion of the right middle cerebral artery. In the sham-operated group, rats were merely subjected to vessel dissociation. In the normal control group, rats were not modeled.MAIN OUTCOME MEASURES: BBB permeability was assessed by determining the level of effusion of Evans blue. MMP-9 expression was detected by an immunohistochemical method.RESULTS: All 90 rats were included in the final analysis. BBB permeability alteration was closely correlated to ischemia/reperfusion time. BBB permeability began to increase at ischemia/reperfusion for 3 hours, then it gradually reached a peak level at ischemia/reperfusion for 1 day, and thereafter it gradually decreased. MMP-9 expression began to increase at ischemia/reperfusion for 3 hours, then gradually reached its peak level 2 days after perfusion, and thereafter

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

    Institute of Scientific and Technical Information of China (English)

    李江明; 胡永均; 童利民; 王大军; 张道敬

    2004-01-01

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

  2. Circulating fibrocytes stabilize blood vessels during angiogenesis in a paracrine manner.

    Science.gov (United States)

    Li, Jinqing; Tan, Hong; Wang, Xiaolin; Li, Yuejun; Samuelson, Lisa; Li, Xueyong; Cui, Caibin; Gerber, David A

    2014-02-01

    Accumulating evidence supports that circulating fibrocytes play important roles in angiogenesis. However, the specific role of fibrocytes in angiogenesis and the underlying mechanisms remain unclear. In this study, we found that fibrocytes stabilized newly formed blood vessels in a mouse wound-healing model by inhibiting angiogenesis during the proliferative phase and inhibiting blood vessel regression during the remodeling phase. Fibrocytes also inhibited angiogenesis in a Matrigel mouse model. In vitro study showed that fibrocytes inhibited both the apoptosis and proliferation of vascular endothelial cells (VECs) in a permeable support (Transwell) co-culture system. In a three-dimensional collagen gel, fibrocytes stabilized the VEC tubes by decreasing VEC tube density on stimulation with growth factors and preventing VEC tube regression on withdrawal of growth factors. Further mechanistic investigation revealed that fibrocytes expressed many prosurvival factors that are responsible for the prosurvival effect of fibrocytes on VECs and blood vessels. Fibrocytes also expressed angiogenesis inhibitors, including thrombospondin-1 (THBS1). THBS1 knockdown partially blocked the fibrocyte-induced inhibition of VEC proliferation in the Transwell co-culture system and recovered the fibrocyte-induced decrease of VEC tube density in collagen gel. Purified fibrocytes transfected with THBS1 siRNA partially recovered the fibrocyte-induced inhibition of angiogenesis in both the wound-healing and Matrigel models. In conclusion, our findings reveal that fibrocytes stabilize blood vessels via prosurvival factors and anti-angiogenic factors, including THBS1. PMID:24300950

  3. Mass Spectrometry and Antibody-Based Characterization of Blood Vessels from Brachylophosaurus canadensis.

    Science.gov (United States)

    Cleland, Timothy P; Schroeter, Elena R; Zamdborg, Leonid; Zheng, Wenxia; Lee, Ji Eun; Tran, John C; Bern, Marshall; Duncan, Michael B; Lebleu, Valerie S; Ahlf, Dorothy R; Thomas, Paul M; Kalluri, Raghu; Kelleher, Neil L; Schweitzer, Mary H

    2015-12-01

    Structures similar to blood vessels in location, morphology, flexibility, and transparency have been recovered after demineralization of multiple dinosaur cortical bone fragments from multiple specimens, some of which are as old as 80 Ma. These structures were hypothesized to be either endogenous to the bone (i.e., of vascular origin) or the result of biofilm colonizing the empty osteonal network after degradation of original organic components. Here, we test the hypothesis that these structures are endogenous and thus retain proteins in common with extant archosaur blood vessels that can be detected with high-resolution mass spectrometry and confirmed by immunofluorescence. Two lines of evidence support this hypothesis. First, peptide sequencing of Brachylophosaurus canadensis blood vessel extracts is consistent with peptides comprising extant archosaurian blood vessels and is not consistent with a bacterial, cellular slime mold, or fungal origin. Second, proteins identified by mass spectrometry can be localized to the tissues using antibodies specific to these proteins, validating their identity. Data are available via ProteomeXchange with identifier PXD001738. PMID:26595531

  4. Making Ends Meet: Myeloid Cells Catalyze Blood Vessel Repair in the Brain.

    Science.gov (United States)

    Deczkowska, Aleksandra; Schwartz, Michal

    2016-05-17

    Hemorrhagic stroke, primarily caused by rupture of blood vessels in the brain, is a leading cause of death and disability in adults. In this issue of Immunity, Liu et al. (2016) demonstrate that repair of cerebrovascular ruptures can be directly mediated by myeloid cells. PMID:27192572

  5. Blood Vessel Segmentation Using Moving-Window Robust Automatic Threshold Selection

    NARCIS (Netherlands)

    Wilkinson, Michael H.F.; Wijbenga, Tsjipke; Vries, Gijs de; Westenberg, Michel A.

    2003-01-01

    Two moving-window methods, using either flat or Gaussian weighted windows, for local thresholding with Robust Automatic Threshold Selection are developed. The results show that fast segmentation of blood vessels against a varying background and noise is possible at modest computational cost. Volumes

  6. Transdermal drug targeting and functional imaging of tumor blood vessels in the mouse auricle.

    Science.gov (United States)

    Schröder, Hannes; Komljenovic, Dorde; Hecker, Markus; Korff, Thomas

    2016-02-01

    Subcutaneously growing tumors are widely utilized to study tumor angiogenesis and the efficacy of antiangiogenic therapies in mice. To additionally assess functional and morphologic alterations of the vasculature in the periphery of a growing tumor, we exploited the easily accessible and hierarchically organized vasculature of the mouse auricle. By site-specific subcutaneous implantation of a defined preformed mouse B16/F0 melanoma aggregate, a solid tumor nodule developed within 14 d. Growth of the tumor nodule was accompanied by a 4-fold increase in its perfusion as well as a 2- to 4-fold elevated diameter and perfusion of peripheral blood vessels that had connected to the tumor capillary microvasculature. By transdermal application of the anticancer drug bortezomib, tumor growth was significantly diminished by about 50% without provoking side effects. Moreover, perfusion and tumor microvessel diameter as well as growth and perfusion of arterial or venous blood vessels supplying or draining the tumor microvasculature were decreased under these conditions by up to 80%. Collectively, we observed that the progressive tumor growth is accompanied by the enlargement of supplying and draining extratumoral blood vessels. This process was effectively suppressed by bortezomib, thereby restricting the perfusion capacity of both extra and intratumoral blood vessels. PMID:26546130

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

    Science.gov (United States)

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

    2013-03-01

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

  8. Age-related changes in regional cerebral blood flow and brain volume in healthy subjects

    International Nuclear Information System (INIS)

    Using the xenon-133 inhalation method, we studied the age-related decline in regional cerebral blood flow, calculated as the initial slope index (ISI), in neurologically normal subjects without any risk factors for cerebral arteriosclerosis (154 men and 123 women), ranging in age from 19 to 88 years. The decline in the ISI was rapid in younger age groups and gradual in older age groups. The ISI was higher in women than in men older than 40 years. Using computed tomography, we studied the age-related decline in brain volume index (BVI; 100% X brain volume/cranial cavity volume) in neurologically normal subjects without any risk factors for cerebral arteriosclerosis (92 men and 49 women), ranging in age from 37 to 86 years. The decline in the BVI was gradual in younger age groups and rapid in older age groups. The BVI was higher in women than in men older than 60 years

  9. Stable xenon CT measurement of cerebral blood flow in cardiac transplantation candidates: Correlation with cognitive function

    International Nuclear Information System (INIS)

    Thirteen consecutive unselected patients with NYHA class 4 cardiac failure referred for cardiac transplantation underwent neurologic examination and cerebral blood flow measurement (rCBF) using the stable xenon enhanced CT method on a GE9800 system. Eleven men and two women were studied (mean age = 43.8 +- 6.1). On neurological examination, six of the patients demonstrated normal mental function; the remaining seven patients demonstrated memory, language, or learning impairment. There was no difference in mean cardiac output between the groups (4.9 L/min +- 1.68 vs. 4.2L/min +- 1.57). rCBF was significantly reduced in the impaired group. Cognitive impairment in patients with cardiac failure can be correlated with cerebral ischemia. Stable xenon CT measurement of rCBF in transplant candidates may help identify patients requiring more rapid transplantation to prevent permanent cerebral injury

  10. Measurement of local cerebral blood flow with (/sup 14/C)iodoantipyrine in the mouse

    Energy Technology Data Exchange (ETDEWEB)

    Jay, T.M.; Lucignani, G.; Crane, A.M.; Jehle, J.; Sokoloff, L.

    1988-02-01

    Local cerebral blood flow was measured in the mouse by means of the (/sup 14/C)iodoantipyrine method. This method has been previously used in the monkey, dog, cat, and rat, but its application to small mammals such as the mouse requires special attention to potential sources of error. The small size of the mouse brain requires special attention to the rapid removal and freezing of the brain to minimize effects of postmortem diffusion of tracer in the tissue. Because of the relatively low diameter/length ratios of the catheters needed for arterial sampling in small animals, substantial errors can occur in the determination of the time course of the (/sup 14/C)iodoantipyrine concentration in the arterial blood unless corrections for lag time and dead space washout in the catheter are properly applied. Local cerebral blood flow was measured in seven awake mice with appropriate care to minimize these sources of error. The values were found to vary from 48 ml/100 g/min in the corpus callosum to 198 ml/100 g/min in the inferior colliculus. The results demonstrate that the (/sup 14/C)iodoantipyrine method can be used to measure local cerebral blood flow in the mouse and that the values in that species are, in general, somewhat higher than those in the rat.

  11. Evidence of redistribution of cerebral blood flow during treatment for an intracranial arteriovenous malformation

    International Nuclear Information System (INIS)

    The presence of an intracranial arteriovenous malformation has a dramatic impact on local circulatory dynamics. Treatment of some arteriovenous malformations can result in disastrous hyperemic states caused by redistribution of previously shunted blood. This report describes serial hemodynamic measurements of both cerebral blood flow and flow velocity in 3 patients during treatment for arteriovenous malformations. Measurements of cerebral blood flow were made by computed tomographic scan employing the stable xenon inhalation technique; flow velocity, including autoregulatory characteristics, was measured by transcranial Doppler ultrasonogram. Substantial hyperemia developed in one patient (Case 1) after resection and in another (Case 3) after embolization. Embolization resulted in restoration of normal regional cerebral blood flow in a patient who demonstrated hypoperfusion before treatment (Case 2). In Patient 1, postoperative hyperemia was associated with persistently elevated flow velocities, and may have been accompanied by hemispheric neurological deficits. Sequential hemodynamic measurements may predict patients at risk of perioperative complications, and may become useful clinical guidelines for the extent and timing of embolization and for the timing of surgery after intracranial hemorrhage or preoperative embolization procedures

  12. Evidence of redistribution of cerebral blood flow during treatment for an intracranial arteriovenous malformation

    Energy Technology Data Exchange (ETDEWEB)

    Batjer, H.H.; Purdy, P.D.; Giller, C.A.; Samson, D.S. (Univ. of Texas Southwestern Medical Center, Dallas (USA))

    1989-10-01

    The presence of an intracranial arteriovenous malformation has a dramatic impact on local circulatory dynamics. Treatment of some arteriovenous malformations can result in disastrous hyperemic states caused by redistribution of previously shunted blood. This report describes serial hemodynamic measurements of both cerebral blood flow and flow velocity in 3 patients during treatment for arteriovenous malformations. Measurements of cerebral blood flow were made by computed tomographic scan employing the stable xenon inhalation technique; flow velocity, including autoregulatory characteristics, was measured by transcranial Doppler ultrasonogram. Substantial hyperemia developed in one patient (Case 1) after resection and in another (Case 3) after embolization. Embolization resulted in restoration of normal regional cerebral blood flow in a patient who demonstrated hypoperfusion before treatment (Case 2). In Patient 1, postoperative hyperemia was associated with persistently elevated flow velocities, and may have been accompanied by hemispheric neurological deficits. Sequential hemodynamic measurements may predict patients at risk of perioperative complications, and may become useful clinical guidelines for the extent and timing of embolization and for the timing of surgery after intracranial hemorrhage or preoperative embolization procedures.

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

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  14. Cerebral blood flow single-photon emission tomography with 123I-IMP in vascular dementia

    International Nuclear Information System (INIS)

    Cerebral blood flow differences between patients with vascular dementia, patients with multiple lacunar infarction without cognitive dysfunction, and age-matched controls were examined. Thirty four patients with vascular dementia (VD) were selected from consecutive referrals to the Memory Clinic at Narita Memorial Hospital. All the patients had routine assessment including history, physical and neurological examinations, neuropsychological assessment, blood tests, EEG, head MRI, and single photon emission computed tomography (SPECT). All of them fulfilled the NINDS-AIREN diagnostic criteria for vascular dementia. Thirty nine patients with multiple lacunar infarction without cognitive dysfunction and 110 age-matched controls were included in this study. Mean cerebral blood flow (mCBF) and regional cerebral blood flow (rCBF) were measured using N-isopropyl-P-123I-iodoamphetamine (123I-IMP) and SPECT imager. The mCBF in VD was 27.6±5.3 ml/100 g/min, while those in the control group and multiple lacunar infarction without cognitive dysfunction were 36.6±6.1 ml/100 g/min and 32.5±5.5 ml/100 g/min, respectively. The patients with VD demonstrated significantly reduced mCBF and rCBF in twenty regions including both cerebellar hemispheres as compared with those of the control group. Although there was no significant rCBF differences in bilateral inferior occipital regions and the right cerebellar hemisphere between patients with VD and multiple lacunar infarction without cognitive dysfunction, we could find significant lower rCBF in the remaining brain areas. In spite of the severity of VD, the diffuse decrease of cerebral blood flow was recognized in all patients with VD. (author)

  15. Finite-sized gas bubble motion in a blood vessel: non-Newtonian effects.

    Science.gov (United States)

    Mukundakrishnan, Karthik; Ayyaswamy, Portonovo S; Eckmann, David M

    2008-09-01

    We have numerically investigated the axisymmetric motion of a finite-sized nearly occluding air bubble through a shear-thinning Casson fluid flowing in blood vessels of circular cross section. The numerical solution entails solving a two-layer fluid model--a cell-free layer and a non-Newtonian core together with the gas bubble. This problem is of interest to the field of rheology and for gas embolism studies in health sciences. The numerical method is based on a modified front-tracking method. The viscosity expression in the Casson model for blood (bulk fluid) includes the hematocrit [the volume fraction of red blood cells (RBCs)] as an explicit parameter. Three different flow Reynolds numbers, Reapp=rholUmaxdmicroapp , in the neighborhood of 0.2, 2, and 200 are investigated. Here, rhol is the density of blood, Umax is the centerline velocity of the inlet Casson profile, d is the diameter of the vessel, and microapp is the apparent viscosity of whole blood. Three different hematocrits have also been considered: 0.45, 0.4, and 0.335. The vessel sizes considered correspond to small arteries, and small and large arterioles in normal humans. The degree of bubble occlusion is characterized by the ratio of bubble to vessel radius (aspect ratio), lambda , in the range 0.9 - --> +) imparted to the cell surface during bubble motion; (iii) large shear stress gradients together with sign reversals are ascribable to the development of a recirculation vortex at the rear of the bubble; (iv) computed magnitudes of shear stress gradients coupled with their sign reversals may correspond to levels that cause injury to the cell by membrane disruption through impulsive compression and stretching; and (v) for the vessel sizes and flow rates investigated, gravitational effects are negligible. PMID:18851139

  16. Cerebral Blood Flow Links Insulin Resistance and Baroreflex Sensitivity

    OpenAIRE

    Ryan, John P.; Sheu, Lei K.; Verstynen, Timothy D.; Onyewuenyi, Ikechukwu C.; Gianaros, Peter J.

    2013-01-01

    Insulin resistance confers risk for diabetes mellitus and associates with a reduced capacity of the arterial baroreflex to regulate blood pressure. Importantly, several brain regions that comprise the central autonomic network, which controls the baroreflex, are also sensitive to the neuromodulatory effects of insulin. However, it is unknown whether peripheral insulin resistance relates to activity within central autonomic network regions, which may in turn relate to reduced baroreflex regula...

  17. Comparison of cerebral blood flow and metabolism to flumazenil binding potential in patients with hemodynamic ischemia

    International Nuclear Information System (INIS)

    Because benzodiazepine receptors (BZR) are abundant in the cortex, an accumulation of 11C-flumazenil which selectively bind to BZR may be useful as markers of neuron density. The aims of this study were to clarify the relationship between neuron density and cerebral oxygen metabolism and to investigate the usefulness of 11C-flumazenil PET for detecting misery perfusion. The subjects were 16 patients with either internal carotid or middle cerebral arterial occlusive disease who underwent PET. Regional cerebral blood flow (CBF), regional cerebral oxygen extraction fraction (OEF), regional cerebral metabolic rate for oxygen (CMRO2) and regional cerebrovascular reserve capacity (CVRC) to acetazolamide were calculated. After CBF study, flumazenil binding potential was measured using the [11C] flumazenil bolus injection method. Forty-eight regions of interests (ROIs) were obtained in 16 patients. Flumazenil binding potential was correlated to CMRO2 (r=0.337, p=0.0069), but in 7 of 48 ROIs, CMRO2 decreased, whereas flumazenil binding potential did not change. Seventeen of 29 ROIs with decreased CVRC showed high OEF and the remaining 12 showed normal OEF. Flumazenil binding potential in ROIs with normal OEF was significantly lower than in those with high OEF (p=0.0003). This study demonstrated that 11C-flumazenil PET is useful for detecting misery perfusion in patients with hemodynamic ischemia. (author)

  18. Study of regional cerebral blood flow with IMP-SPECT before and after administration of nilvadipine

    International Nuclear Information System (INIS)

    Regional cerebral blood flow (rCBF) was measured quantitatively by IMP-SPECT before and after administration of nilvadipine. The drug was administered at a dose of 8 mg/day for 8 or more weeks in 7 patients with chronic multiple cerebral infarction, one with hydrocephalus with normal pressure, and one with alcoholic encephalopathy. An average rCBF was increased after administration in all 6 patients with cerebral infarction confined to the perforated branch, with significant difference from the value before administration. In the other with cerebral infarction in both the perforated branch and the cortical branch, however, there was no change in average rCBF. In patients with hydrocephalus and alcoholic encephalopathy, on the other hand, post-administration rCBF tended to be lower than pre-administration rCBF. These results suggest that nilvadipine may be effective in increasing rCBF for patients with cerebral infarction confined to the perforated branch. (N.K.)

  19. Segmentation of blood vessels from red-free and fluorescein retinal images.

    Science.gov (United States)

    Martinez-Perez, M Elena; Hughes, Alun D; Thom, Simon A; Bharath, Anil A; Parker, Kim H

    2007-02-01

    The morphology of the retinal blood vessels can be an important indicator for diseases like diabetes, hypertension and retinopathy of prematurity (ROP). Thus, the measurement of changes in morphology of arterioles and venules can be of diagnostic value. Here we present a method to automatically segment retinal blood vessels based upon multiscale feature extraction. This method overcomes the problem of variations in contrast inherent in these images by using the first and second spatial derivatives of the intensity image that gives information about vessel topology. This approach also enables the detection of blood vessels of different widths, lengths and orientations. The local maxima over scales of the magnitude of the gradient and the maximum principal curvature of the Hessian tensor are used in a multiple pass region growing procedure. The growth progressively segments the blood vessels using feature information together with spatial information. The algorithm is tested on red-free and fluorescein retinal images, taken from two local and two public databases. Comparison with first public database yields values of 75.05% true positive rate (TPR) and 4.38% false positive rate (FPR). Second database values are of 72.46% TPR and 3.45% FPR. Our results on both public databases were comparable in performance with other authors. However, we conclude that these values are not sensitive enough so as to evaluate the performance of vessel geometry detection. Therefore we propose a new approach that uses measurements of vessel diameters and branching angles as a validation criterion to compare our segmented images with those hand segmented from public databases. Comparisons made between both hand segmented images from public databases showed a large inter-subject variability on geometric values. A last evaluation was made comparing vessel geometric values obtained from our segmented images between red-free and fluorescein paired images with the latter as the "ground truth

  20. P/Q-type and T-type voltage-gated calcium channels are involved in the contraction of mammary and brain blood vessels from hypertensive patients

    DEFF Research Database (Denmark)

    Thuesen, A D; Lyngsø, K S; Rasmussen, L;

    2016-01-01

    AIM: Calcium channel blockers are widely used in cardiovascular diseases. Besides L-type channels, T- and P/Q-type calcium channels are involved in the contraction of human renal blood vessels. It was hypothesized that T- and P/Q-type channels are involved in the contraction of human brain and...... P/Q-type antagonist ω-agatoxin IVA (10(-8) mol L(-1) ) and the T-type calcium blocker mibefradil (10(-7) mol L(-1) ) inhibited KCl depolarization-induced contraction in mammary arteries from hypertensive patients with no effect on blood vessels from normotensive patients. ω-Agatoxin IVA decreased...... contraction in cerebral arterioles from hypertensive patients. L-type blocker nifedipine abolished the contraction in mammary arteries. PCR analysis showed expression of P/Q-type (Cav 2.1), T-type (Cav 3.1 and Cav 3.2) and L-type (Cav 1.2) calcium channels in mammary and cerebral arteries. Immunohistochemical...

  1. The influence on PGI2-like activity of blood vessel wall following γ ray irradiation

    International Nuclear Information System (INIS)

    In the previous work, it has been shown that the reaction of blood platelet aggregation is risen during the early days following γ ray irradiation of large doses. In this paper, the changes of Rat PGI2-like activity with inhibiting platelet aggregation after γ ray irradiation of 8 Gy are reported. The results indicated that the activity was reduced at the first day after radiation, then recovered at the third day, lowered again at the 5-7 days. The changes have significant concern between the increase of blood platelet aggregation of Rats and the inhibition of PGI2-like activity of blood vessel wall following γ ray irradiation

  2. The effect of changes in cerebral blood flow on cognitive function during exercise.

    Science.gov (United States)

    Ogoh, Shigehiko; Tsukamoto, Hayato; Hirasawa, Ai; Hasegawa, Hiroshi; Hirose, Norikazu; Hashimoto, Takeshi

    2014-09-01

    No studies have identified the direct effect of changes in cerebral blood flow (CBF) on cognitive function at rest and during exercise. In this study, we manipulated CBF using hypercapnic gas to examine whether an increase in CBF improves cognitive function during prolonged exercise. The speed and the accuracy of cognitive function were assessed using the Stroop color-word test. After the Stroop test at rest, the subjects began exercising on a cycling ergometer in which the workload was increased by 0.5 kilopond every minute until a target heart rate of 140 beats/min was achieved. Then, the subjects continued to cycle at a constant rate for 50 min. At four time points during the exercise (0, 10, 20, 50 min), the subjects performed a Stroop test with and without hypercapnic respiratory gas (2.0% CO2), with a random order of the exposures in the two tests. Despite a decrease in the mean blood flow velocity in the middle cerebral artery (MCA Vmean), the reaction time for the Stroop test gradually decreased during the prolonged exercise without any loss of performance accuracy. In addition, the hypercapnia-induced increase in MCA Vmean produced neither changes in the reaction time nor error in the Stroop test during exercise. These findings suggest that the changes in CBF are unlikely to affect cognitive function during prolonged exercise. Thus, we conclude that improved cognitive function may be due to cerebral neural activation associated with exercise rather than global cerebral circulatory condition. PMID:25263210

  3. pCO2 And pH regulation of cerebral blood flow

    Directory of Open Access Journals (Sweden)

    SeongHun eYoon

    2012-09-01

    Full Text Available CO2 Serves as one of the fundamental regulators of cerebral blood flow. It is widely considered that this regulation occurs through pCO2-driven changes in pH of the cerebral spinal fluid, with elevated and lowered pH causing direct relaxation and contraction of the smooth muscle, respectively. However, some findings also suggest that pCO2 acts independently of and/or in conjunction with altered pH. This action may be due to a direct effect of cerebral spinal fluid pCO2 on the smooth muscle as well as on the endothelium, nerves, and astrocytes. Findings may also point to an action of arterial pCO2 on the endothelium to regulate smooth muscle contractility. Thus, the effects of pH and pCO2 may be influenced by the absence/presence of different cell types in the various experimental preparations. Results may also be influenced by experimental parameters including myogenic tone as well as solutions containing significantly altered HCO3- concentrations, i.e., solutions routinely employed to differentiate the effects of pH from pCO2. In sum, it appears that pCO2, independently and in conjunction with pH, may regulate cerebral blood flow.

  4. On ultrasound-induced microbubble oscillation in a capillary blood vessel and its implications for the blood-brain barrier

    Science.gov (United States)

    Wiedemair, W.; Tuković, Ž.; Jasak, H.; Poulikakos, D.; Kurtcuoglu, V.

    2012-02-01

    The complex interaction between an ultrasound-driven microbubble and an enclosing capillary microvessel is investigated by means of a coupled, multi-domain numerical model using the finite volume formulation. This system is of interest in the study of transient blood-brain barrier disruption (BBBD) for drug delivery applications. The compliant vessel structure is incorporated explicitly as a distinct domain described by a dedicated physical model. Red blood cells (RBCs) are taken into account as elastic solids in the blood plasma. We report the temporal and spatial development of transmural pressure (Ptm) and wall shear stress (WSS) at the luminal endothelial interface, both of which are candidates for the yet unknown mediator of BBBD. The explicit introduction of RBCs shapes the Ptm and WSS distributions and their derivatives markedly. While the peak values of these mechanical wall parameters are not affected considerably by the presence of RBCs, a pronounced increase in their spatial gradients is observed compared to a configuration with blood plasma alone. The novelty of our work lies in the explicit treatment of the vessel wall, and in the modelling of blood as a composite fluid, which we show to be relevant for the mechanical processes at the endothelium.

  5. Cerebral Blood Flow Changes in Glioblastoma Patients Undergoing Bevacizumab Treatment Are Seen in Both Tumor and Normal Brain

    OpenAIRE

    Andre, Jalal B; Nagpal, Seema; Hippe, Daniel S; Ravanpay, Ali C.; Schmiedeskamp, Heiko; Bammer, Roland; Palagallo, Gerald J; Recht, Lawrence; Zaharchuk, Greg

    2015-01-01

    Bevacizumab (BEV) is increasingly used to treat recurrent glioblastoma (GBM) with some reported improvement in neurocognitive function despite potential neurotoxicities. We examined the effects of BEV on cerebral blood flow (CBF) within recurrent GBM tumor and in the contralateral middle cerebral artery (MCA) territory.

  6. Peristaltic Pumping of Blood in micro-vessels of Non-uniform Cross-section

    CERN Document Server

    Misra, J C

    2010-01-01

    The paper is devoted to a study of the peristaltic motion of blood in the micro-circulatory system. The vessel is considered of non-uniform cross-section. The progressive peristaltic waves are taken to be of sinusoidal nature. The Reynolds number is considered to be small. Blood is considered to be a Herschel-Bulkley fluid. Of particular concern here is to investigate the effects of amplitude ratio, mean pressure gradient, yield stress and the power law index on the velocity distribution, streamline pattern and wall shear stress. Basing upon the study, extensive numerical calculations has been made. The study reveals that peristaltic pumping as well as velocity and wall shear stress are appreciably affected due to the non-uniform geometry of blood vessels. They are also highly sensitive to the magnitude of the amplitude of the amplitude ratio and the value of the fluid index.

  7. Indication of recanalization therapy in acute ischemic stroke determined by quantitative evaluation of cerebral blood flow by SPECT

    International Nuclear Information System (INIS)

    Recanalization of occluded vessels has been attempted for the treatment of acute hemispheric ischemic stroke, but increases the risk of hemorrhage. The purpose of this study is to determine the indications for recanalization therapy in acute ischemic stroke by quantitative evaluation of cerebral blood flow by SPECT. We studied retrospectively the relationship between regional cerebral blood flow (rCBF) measured by 99mTc-HM-PAO SPECT before treatment and the radiological final outcome in 9 patients, who had hemispheric ishemic strokes and underwent successful recanalization of the occluded artery by endovascular technique within 6 hours after onset. A noninvasive method described by Matsuda et al (Patlak plot) was used for the quantitative measurement of rCBF with SPECT. The results showed that the low value of rCBF before treatment correlated with the development of infarction after recanalization. When recanalization was achieved between 2 and 6 hours after onset, the critical level of rCBF to develop infarction was 25-30 ml/100 g/min. Despite early recanalization, one patient with a significant rCBF defect suffered from hemorrhagic transformation after recanalization. The measurement of rCBF by 99mTc-HM-PAO SPECT is available for emergent cases and is very useful to determine the extent and the degree of ischemic insult in acute ischemic strokes. Our data indicate that if the residual rCBF, measured by SPECT, is over 25 ml/100 g/min, emergent recanalization therapy should be considered, while on the other hand, if the residual rCBF is severely reduced (below 20 ml/100 g/min), acute recanalization is contraindicated to avoid fatal hemorrhagic transformation. A prospective study to enhance our preliminary results is needed. (author)

  8. Indication of recanalization therapy in acute ischemic stroke determined by quantitative evaluation of cerebral blood flow by SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Umemura, Atsushi; Suzuka, Tomonao; Nakamura, Akihiro [Hamamatsu Social Insurance Hospital, Shizuoka (Japan)

    1999-03-01

    Recanalization of occluded vessels has been attempted for the treatment of acute hemispheric ischemic stroke, but increases the risk of hemorrhage. The purpose of this study is to determine the indications for recanalization therapy in acute ischemic stroke by quantitative evaluation of cerebral blood flow by SPECT. We studied retrospectively the relationship between regional cerebral blood flow (rCBF) measured by {sup 99m}Tc-HM-PAO SPECT before treatment and the radiological final outcome in 9 patients, who had hemispheric ishemic strokes and underwent successful recanalization of the occluded artery by endovascular technique within 6 hours after onset. A noninvasive method described by Matsuda et al (Patlak plot) was used for the quantitative measurement of rCBF with SPECT. The results showed that the low value of rCBF before treatment correlated with the development of infarction after recanalization. When recanalization was achieved between 2 and 6 hours after onset, the critical level of rCBF to develop infarction was 25-30 ml/100 g/min. Despite early recanalization, one patient with a significant rCBF defect suffered from hemorrhagic transformation after recanalization. The measurement of rCBF by {sup 99m}Tc-HM-PAO SPECT is available for emergent cases and is very useful to determine the extent and the degree of ischemic insult in acute ischemic strokes. Our data indicate that if the residual rCBF, measured by SPECT, is over 25 ml/100 g/min, emergent recanalization therapy should be considered, while on the other hand, if the residual rCBF is severely reduced (below 20 ml/100 g/min), acute recanalization is contraindicated to avoid fatal hemorrhagic transformation. A prospective study to enhance our preliminary results is needed. (author)

  9. BH4 treatment in BH4-responsive PKU patients: preliminary data on blood prolactin concentrations suggest increased cerebral dopamine concentrations.

    Science.gov (United States)

    van Vliet, Danique; Anjema, Karen; Jahja, Rianne; de Groot, Martijn J; Liemburg, Geertje B; Heiner-Fokkema, M Rebecca; van der Zee, Eddy A; Derks, Terry G J; Kema, Ido P; van Spronsen, Francjan J

    2015-01-01

    In phenylketonuria (PKU), cerebral neurotransmitter deficiencies have been suggested to contribute to brain dysfunction. Present treatment aims to reduce blood phenylalanine concentrations by a phenylalanine-restricted diet, while in some patients blood phenylalanine concentrations also respond to cofactor treatment with tetrahydrobiopterin (BH4). Recently, a repurposing approach of BH4 was suggested to increase cerebral neurotransmitter synthesis. To investigate whether BH4 may improve cerebral dopamine concentrations in PKU patients beyond its effect through lowering blood phenylalanine concentrations, we investigated blood prolactin concentrations-as a parameter of brain dopamine availability. We retrospectively compared blood prolactin in relation to blood phenylalanine concentrations of nine (male) BH4-responsive PKU patients, when being treated without and with BH4. Blood prolactin concentrations positively correlated to blood phenylalanine concentrations (p=0.002), being significantly lower with than without BH4 treatment (p=0.047). In addition, even in this small number of male patients, blood prolactin concentrations tended to be lower at increasing BH4 dose (p=0.054), while taking blood phenylalanine concentrations into account (p=0.002). In individual BH4-responsive patients, median blood prolactin concentrations were significantly lower while using BH4 than before using BH4 treatment (p=0.024), whereas median blood phenylalanine concentrations tended to be lower, but this did not reach statistical significance (p=0.107). Therefore, these data show that high blood phenylalanine in BH4-responsive PKU male patients seems to be associated with increased blood prolactin concentrations, suggesting reduced cerebral dopamine availability. Moreover, these data suggest that BH4 treatment in itself could decrease blood prolactin concentrations in a dose-responsive way, independent of blood phenylalanine concentrations. We conclude that these preliminary data

  10. Measurement of cerebral blood flow rate and its relationship with brain function using optical coherence tomography

    Science.gov (United States)

    Liu, Jian; Wang, Yi; Zhao, Yuqian; Dou, Shidan; Ma, Yushu; Ma, Zhenhe

    2016-03-01

    Activity of brain neurons will lead to changes in local blood flow rate (BFR). Thus, it is important to measure the local BFR of cerebral cortex on research of neuron activity in vivo, such as rehabilitation evaluation after stroke, etc. Currently, laser Doppler flowmetry is commonly used for blood flow measurement, however, relatively low resolution limits its application. Optical coherence tomography (OCT) is a powerful noninvasive 3D imaging modality with high temporal and spatial resolutions. Furthermore, OCT can provide flow distribution image by calculating Doppler frequency shift which makes it possible for blood flow rate measurement. In this paper, we applied OCT to measure the blood flow rate of the primary motor cortex in rats. The animal was immobilized and anesthetized with isoflurane, an incision was made along the sagittal suture, and bone was exposed. A skull window was opened on the primary motor cortex. Then, blood flow rate changes in the primary motor cortex were monitored by our homemade spectral domain OCT with a stimulation of the passive movement of the front legs. Finally, we established the relationship between blood flow rate and the test design. The aim is to demonstrate the potential of OCT in the evaluation of cerebral cortex function.

  11. Associations between arterial stiffness, depressive symptoms and cerebral small vessel disease: cross-sectional findings from the AGES-Reykjavik Study

    Science.gov (United States)

    van Sloten, Thomas T.; Mitchell, Gary F.; Sigurdsson, Sigurdur; van Buchem, Mark A.; Jonsson, Palmi V.; Garcia, Melissa E.; Harris, Tamara B.; Henry, Ronald M.A.; Levey, Andrew S.; Stehouwer, Coen D.A.; Gudnason, Vilmundur; Launer, Lenore J.

    2016-01-01

    Background Arterial stiffness may contribute to depression via cerebral microvascular damage, but evidence for this is scarce. We therefore investigated whether arterial stiffness is associated with depressive symptoms and whether cerebral small vessel disease contributes to this association. Methods This cross-sectional study included a subset of participants from the AGES-Reykjavik study second examination round, which was conducted from 2007 to 2011. Arterial stiffness (carotid–femoral pulse wave velocity [CFPWV]), depressive symptoms (15-item geriatric depression scale [GDS-15]) and cerebral small vessel disease (MRI) were determined. Manifestations of cerebral small vessel disease included higher white matter hyperintensity volume, subcortical infarcts, cerebral microbleeds, Virchow–Robin spaces and lower total brain parenchyma volume. Results We included 2058 participants (mean age 79.6 yr; 59.0% women) in our analyses. Higher CFPWV was associated with a higher GDS-15 score, after adjustment for potential confounders (β 0.096, 95% confidence interval [CI] 0.005–0.187). Additional adjustment for white matter hyperintensity volume or subcortical infarcts attenuated the association between CFPWV and the GDS-15 score, which became nonsignificant (p > 0.05). Formal mediation tests showed that the attenuating effects of white matter hyperintensity volume and subcortical infarcts were statistically significant. Virchow–Robin spaces, cerebral microbleeds and cerebral atrophy did not explain the association between CFPWV and depressive symptoms. Limitations Our study was limited by its cross-sectional design, which precludes any conclusions about causal mediation. Depressive symptoms were assessed by a self-report questionnaire. Conclusion Greater arterial stiffness is associated with more depressive symptoms; this association is partly accounted for by white matter hyperintensity volume and subcortical infarcts. This study supports the hypothesis that

  12. Xe-133 SPECT regional cerebral blood flow in Japanese subjects reading Kana versus Kanji texts

    International Nuclear Information System (INIS)

    Purpose: Kana and Kanji (written forms of Japanese processed in uncertain cortical locations) may differ from each other in the brain hemisphere used in processing. This paper reports single-photon emission CT (SPECT) used to evaluate the regional cerebral blood flow (RCBF) during reading. The authors studied seven normal right-handed subjects with intravenous Xe-133 in saline and brain-dedicated SPECT (Tomomatic). The RCBF was calculated for each task and displayed in a color-coded image. Control rest study was followed by silent reading of simple Kana (phonetic) words and then Kanji (pictorial) words. All subjects had increased cerebral blood flow (∼ 30%) with reading. For Kana and Kanji, the frontoparietal increase was bilateral in two subjects, left-sided in three, and right-sided in one. In one subject, the frontoparietal increase was more left-sided for Kana and symmetrical for Kanji

  13. Assessment of cerebral blood flow autoregulation (CBF AR) with rheoencephalography (REG): studies in animals

    International Nuclear Information System (INIS)

    The ability of cerebral vasculature to regulate cerebral blood flow (CBF) in the face of changes in arterial blood pressure (SAP) or intracranial pressure (ICP) is an important guard against secondary ischemia in acute brain injuries, and official guidelines recommend that therapeutic decisions be guided by continuous monitoring of CBF autoregulation (AR). The common method for CBF AR monitoring, which rests on real-time derivation of the correlation coefficient (PRx) between slow oscillations in SAP and ICP is, however, rarely used in clinical practice because it requires invasive ICP measurements. This study investigated whether the correlation coefficient between SAP and the pulsatile component of the non-invasive transcranial bioimpedance signal (rheoencephalography, REG) could be used to assess the state and lower limit of CBF AR. The results from pigs and rhesus macaques affirm the utility of REG; however, additional animal and clinical studies are warranted to assess selectivity of automatic REG-based evaluation of CBF AR.

  14. Assessment of cerebral blood flow autoregulation (CBF AR) with rheoencephalography (REG): studies in animals

    Science.gov (United States)

    Popovic, Djordje; Bodo, Michael; Pearce, Frederick; van Albert, Stephen; Garcia, Alison; Settle, Tim; Armonda, Rocco

    2013-04-01

    The ability of cerebral vasculature to regulate cerebral blood flow (CBF) in the face of changes in arterial blood pressure (SAP) or intracranial pressure (ICP) is an important guard against secondary ischemia in acute brain injuries, and official guidelines recommend that therapeutic decisions be guided by continuous monitoring of CBF autoregulation (AR). The common method for CBF AR monitoring, which rests on real-time derivation of the correlation coefficient (PRx) between slow oscillations in SAP and ICP is, however, rarely used in clinical practice because it requires invasive ICP measurements. This study investigated whether the correlation coefficient between SAP and the pulsatile component of the non-invasive transcranial bioimpedance signal (rheoencephalography, REG) could be used to assess the state and lower limit of CBF AR. The results from pigs and rhesus macaques affirm the utility of REG; however, additional animal and clinical studies are warranted to assess selectivity of automatic REG-based evaluation of CBF AR.

  15. Optics based signal processing methods for intraoperative blood vessel detection and quantification in real time (Conference Presentation)

    Science.gov (United States)

    Chaturvedi, Amal; Shukair, Shetha A.; Le Rolland, Paul; Vijayvergia, Mayank; Subramanian, Hariharan; Gunn, Jonathan W.

    2016-03-01

    Minimally invasive operations require surgeons to make difficult cuts to blood vessels and other tissues with impaired tactile and visual feedback. This leads to inadvertent cuts to blood vessels hidden beneath tissue, causing serious health risks to patients and a non-reimbursable financial burden to hospitals. Intraoperative imaging technologies have been developed, but these expensive systems can be cumbersome and provide only a high-level view of blood vessel networks. In this research, we propose a lean reflectance-based system, comprised of a dual wavelength LED, photodiode, and novel signal processing algorithms for rapid vessel characterization. Since this system takes advantage of the inherent pulsatile light absorption characteristics of blood vessels, no contrast agent is required for its ability to detect the presence of a blood vessel buried deep inside any tissue type (up to a cm) in real time. Once a vessel is detected, the system is able to estimate the distance of the vessel from the probe and the diameter size of the vessel (with a resolution of ~2mm), as well as delineate the type of tissue surrounding the vessel. The system is low-cost, functions in real-time, and could be mounted on already existing surgical tools, such as Kittner dissectors or laparoscopic suction irrigation cannulae. Having been successfully validated ex vivo, this technology will next be tested in a live porcine study and eventually in clinical trials.

  16. Regional cerebral blood flow in psychiatry: Application to clinical research

    International Nuclear Information System (INIS)

    In the following sections, the authors describe aspects of the xenon-133 inhalation technique as it has been modified in their lab, as well as a number of considerations and prerequisites for setting up such a facility. The authors also discuss the processes by which they technically and clinically validated the methods used. Several case studies follow along with descriptions of the approaches they are taking in investigating psychiatric illnesses with rCBF. Since the concept of a relation between brain functional activity, metabolism, and blood flow has a long history, both in theory and in practice, they first briefly review some of this history and some of the principles involved

  17. A comparison of blood vessel features and local binary patterns for colorectal polyp classification

    Science.gov (United States)

    Gross, Sebastian; Stehle, Thomas; Behrens, Alexander; Auer, Roland; Aach, Til; Winograd, Ron; Trautwein, Christian; Tischendorf, Jens

    2009-02-01

    Colorectal cancer is the third leading cause of cancer deaths in the United States of America for both women and men. By means of early detection, the five year survival rate can be up to 90%. Polyps can to be grouped into three different classes: hyperplastic, adenomatous, and carcinomatous polyps. Hyperplastic polyps are benign and are not likely to develop into cancer. Adenomas, on the other hand, are known to grow into cancer (adenoma-carcinoma sequence). Carcinomas are fully developed cancers and can be easily distinguished from adenomas and hyperplastic polyps. A recent narrow band imaging (NBI) study by Tischendorf et al. has shown that hyperplastic polyps and adenomas can be discriminated by their blood vessel structure. We designed a computer-aided system for the differentiation between hyperplastic and adenomatous polyps. Our development aim is to provide the medical practitioner with an additional objective interpretation of the available image data as well as a confidence measure for the classification. We propose classification features calculated on the basis of the extracted blood vessel structure. We use the combined length of the detected blood vessels, the average perimeter of the vessels and their average gray level value. We achieve a successful classification rate of more than 90% on 102 polyps from our polyp data base. The classification results based on these features are compared to the results of Local Binary Patterns (LBP). The results indicate that the implemented features are superior to LBP.

  18. Urine Test Strips to Exclude Cerebral Spinal Fluid Blood

    Directory of Open Access Journals (Sweden)

    Marshall, Robin A

    2011-02-01

    Full Text Available Introduction: Determining the presence or absence of red blood cells (RBC or their breakdown products in cerebrospinal fluid (CSF is essential for the evaluation of subarachnoid hemorrhage (SAH in headache patients. Current methodology for finding blood in the CSF is either spectrophotometric detection of pigment, which is time consuming and labor intensive, or visual assesment of samples for color change (xanthochromia, which is inaccurate. Bayer Multistix® urine test strips are designed to test urine for RBC by detecting the presence of hemoglobin. The aim of this pilot study was to evaluate the perfomance of urine reagent test strips for ruling out the presence of RBC in CSF.Methods: We compared color changes on Multistix® urine test strips to the standard of spectrophotometric absorbtion at 415nm and initial RBC counts in 138 visually clear CSF samples.Results: We performed Pearson Chi-Square and likelihood ratios on the results and found a correlation between a negative result on the urine test strip and less than 5 RBC per high power field and a spectrophotometric absorbance of less than 0.02% at 415nm in a CSF sample.Conclusion: These results warrant further investigation in the form of a prospective clinical validation as it may alter the emergency department evaluation for SAH. [West J Emerg Med. 2011;12(1:63-66.

  19. Cerebral blood flow imaged with ultrahigh-resolution optical coherence angiography and Doppler tomography

    OpenAIRE

    Ren, Hugang; Du, Congwu; Pan, Yingtian

    2012-01-01

    Speckle contrast based optical coherence angiography (OCA) and optical coherence Doppler tomography (ODT) have been applied to image cerebral blood flow previously. However, the contrast mechanisms of these two methods are not fully studied. Here, we present both flow phantom and in vivo animal experiments using ultrahigh-resolution OCA (μOCA) and ODT (μODT) to investigate the flow sensitivity differences between these two methods. Our results show that the high sensitivity of μOCA for visual...

  20. Cerebrolysin effects on neurological outcomes and cerebral blood flow in acute ischemic stroke

    OpenAIRE

    Amiri-Nikpour MR; Nazarbaghi S; Ahmadi-Salmasi B; Mokari. T.; Tahamtan U; Rezaei Y

    2014-01-01

    Mohammad Reza Amiri-Nikpour,1 Surena Nazarbaghi,1 Babak Ahmadi-Salmasi,1 Tayebeh Mokari,2 Urya Tahamtan,2 Yousef Rezaei3 1Department of Neurology, Imam Khomeini Hospital, 2School of Medicine, 3Seyyed-al-Shohada Heart Center, Urmia University of Medical Sciences, Urmia, Iran Background: Cerebrolysin, a brain-derived neuropeptide, has been shown to improve the neurological outcomes of stroke, but no study has demonstrated its effect on cerebral blood flow. This study aimed to determine the ce...

  1. Low cerebral blood flow is associated with lower memory function in metabolic syndrome

    OpenAIRE

    Birdsill, Alex C; Carlsson, Cynthia M.; Willette, Auriel A.; Okonkwo, Ozioma C.; Johnson, Sterling C.; Xu, Guofan; Oh, Jennifer M; Gallagher, Catherine L.; Koscik, Rebecca L; Jonaitis, Erin M.; Hermann, Bruce P.; LaRue, Asenath; Rowley, Howard A.; Asthana, Sanjay; Sager, Mark A.

    2013-01-01

    Background Metabolic syndrome (MetS)—a cluster of cardiovascular risk factors—is linked with cognitive decline and dementia. However, the brain changes underlying this link are presently unknown. In this study, we tested the relationship between MetS, cerebral blood flow (CBF), white matter hyperintensity (WMH) burden and gray matter (GM) volume in cognitively healthy late middleaged adults. Additionally, we assessed the extent to which MetS was associated with cognitive performance. Methods ...

  2. The effect of changes in cerebral blood flow on cognitive function during exercise

    OpenAIRE

    Ogoh, Shigehiko; Tsukamoto, Hayato; Hirasawa, Ai; Hasegawa, Hiroshi; Hirose, Norikazu; Hashimoto, Takeshi

    2014-01-01

    Abstract No studies have identified the direct effect of changes in cerebral blood flow (CBF) on cognitive function at rest and during exercise. In this study, we manipulated CBF using hypercapnic gas to examine whether an increase in CBF improves cognitive function during prolonged exercise. The speed and the accuracy of cognitive function were assessed using the Stroop color‐word test. After the Stroop test at rest, the subjects began exercising on a cycling ergometer in which the workload ...

  3. Monitoring cerebral blood flow during intracranial operations: an intravenous injection method

    Energy Technology Data Exchange (ETDEWEB)

    Wyper, D.J.; Pickard, J.D.; Acar, U.

    1979-01-01

    A method of measuring cerebral blood flow during neurosurgery is described. It is an adaptation of the standard 133Xe intravenous injection method, with computation restricted to data collected over the first 3 min. In addition to a theoretical presentation of a method and an analysis of the effect of residual 133Xe activity when sequential runs are performed in close approximation, the technique is validated experimentally by comparison with intracarotid 133Xe injection in baboons.

  4. Voluntary respiratory control and cerebral blood flow velocity upon ice-water immersion

    DEFF Research Database (Denmark)

    Mantoni, Teit; Rasmussen, Jakob Højlund; Belhage, Bo;

    2008-01-01

    In non-habituated subjects, cold-shock response to cold-water immersion causes rapid reduction in cerebral blood flow velocity (approximately 50%) due to hyperventilation, increasing risk of syncope, aspiration, and drowning. Adaptation to the response is possible, but requires several cold...... immersions. This study examines whether thorough instruction enables non-habituated persons to attenuate the ventilatory component of cold-shock response....

  5. A 133-xenon inhalation system for cerebral blood-flow measurements in ventilated premature babies

    International Nuclear Information System (INIS)

    We constructed a Xenon-133 inhalation and trapping system in order to measure cerebral blood flow of ventilated premature babies by means of the noninvasive 133Xe clearance method. The completely lead-shielded inhalation device is a closed system driven by the baby's own respirator and can thus be safely used at the patients bedside in the intensive care unit. Reproducible proximal airway concentrations of 133Xe (with or without leaks around the endotracheal tube) were obtained by in vitro simulation. (orig.)

  6. A study of the acute effect of smoking on cerebral blood flow using 99mTc-ECD SPET

    International Nuclear Information System (INIS)

    Cigarette smoking is known to be associated with atherosclerosis, is an important risk factor for stroke and has other serious effects. The aim of this study was to evaluate the acute effect of cigarette smoking on cerebral blood flow using statistical parametric mapping (SPM). Ten healthy volunteers with a smoking habit were studied using technetium-99m-labelled ethylcysteinate dimer single-photon emission tomography (SPET). We evaluated the regional cerebral blood flow under the smoking and resting states. The regional cerebral blood flow on smoking-activated SPET was significantly decreased in the whole brain as compared with that on resting SPET. Our findings therefore suggest that one of the acute effects of cigarette smoking is to induce a diffuse decrease in cerebral blood flow. (orig.)

  7. Regional cerebral blood flow in patients with transient ischemic attacks studied by Xenon-133 inhalation and emission tomography

    International Nuclear Information System (INIS)

    Cerebral blood flow CBF was studied in 14 patients with transient ischemic attacks TIA and arteriosclerotic neck vessel disease. CBF was measured by a rapidly rotating single photon emission computerized tomograph using Xenon-133 inhalation. This method yields images of 3 brain slices depicting CBF with a spatial resolution of 1.7 cm. Based primarily on the clinical evidence and on the angiographical findings embolism was considered the pathogenetic factor in 10 cases, whereas chronic hemodynamic insufficiency rendered symptomatic by postural factors probably accounted for the symptoms in 4 patients. Of the 14 patients, all studied days to weeks after the most recent TIA, four showed hypoperfused areas on the CBF-tomograms and with roughly the same location hypodense areas on CT-scanning, i.e. areas of complete infarction. However, an additional five patients showed reduction of CBF in areas with no abnormality on the CT-scan. The abnormal blood flow pattern was found to be unchanged after clinically successful reconstructive vascular surgery. This suggests the presence of irreversible ischemic tissue damage without gross emollition (incomplete infarction). It is concluded, that TIAs are often harmful events, as no less than 9 of the 14 patients studied had evidence of complete and/or incomplete infarction. Thorough examination and rational therapy should be instituted as soon as possible to prevent further ischemic lesions

  8. Adaptive ultrasonic measurement of blood vessel diameter and wall thickness: theory and experimental results.

    Science.gov (United States)

    Rafii, K; Jaffe, J S

    1998-01-01

    An adaptive ultrasonic technique for measuring blood vessel diameter and wall thickness is presented. This technique allows one to use a target-specific transmitted waveform/receiver filter to obtain a larger signal-to-noise ratio (SNR) in the received signal than conventional techniques. Generally, SNR of a received wave increases as the intensity of the transmit wave increases; however, because of the FDA limitations placed on the amount of transmit energy, it is important to be able to make the most efficient use of the energy that is available to obtain the best possible SNR in the received signal. Adaptive ultrasonic measurement makes the most efficient use of the energy that is available by placing the maximum amount of energy in the largest target scattering mode. This results in more energy backscatter from a given target, which leads to a higher SNR in the received waveform. Computer simulations of adaptive ultrasonic measurement of blood vessel diameter show that for a SNR of 0 dB in the transmitted waveform, the standard deviation of the diameter measurements for a custom-designed transmitted waveform is about two orders of magnitude less than the standard deviation of the diameter measurements using more conventional waveforms. Diameter and wall thickness measurement experiments were performed on a latex tube and a bovine blood vessel using both custom-made and conventionally used transmitted waveforms. Results show that the adaptively designed waveform gives a smaller uncertainty in the measurements. The adaptive ultrasonic blood vessel diameter and wall thickness measuring technique has potential applications in examining vessels which are either too deep inside the body or too small for conventional techniques to be used, because of the low SNR in the received signal. PMID:18244211

  9. Regional cerebral blood flow and CSF pressures during Cushing response induced by a supratentorial expanding mass

    International Nuclear Information System (INIS)

    In order to delineate the critical blood flow pattern during the Cushing response in intracranial hypertension, regional cerebral blood flow was measured with radioactive microspheres in 12 anesthetized dogs at respiratory arrest caused either by expansion of an epidural supratentorial balloon or by cisternal infusion. Regional cerebrospinal fluid pressures were recorded and the local cerebral perfusion pressure calculated in various cerebrospinal compartments. In the 8 dogs of the balloon expansion group, the systemic arterial pressure was unmanipulated in 4, while it was kept at a constant low level (48 and 70 mm Hg) in 2 dogs and, in another 2 dogs, at a constant high level (150 and 160 mm Hg) induced by infusion of Aramine. At respiratory arrest, regional cerebral blood flow had a stereotyped pattern and was largely independent of the blood pressure level. In contrast, concomitant pressure gradients between the various cerebrospinal compartments varied markedly in the 3 animal groups increasing with higher arterial pressure. Flow decreased by 85-100% supratentorially and by 70-100% in the upper brain stem down to the level of the upper pons, while changes in the lower brain stem were minor, on the average 25%. When intracranial pressure was raised by cisternal infusion in 4 dogs, the supratentorial blood flow pattern at respiratory arrest was appriximately similar to the flow pattern in the balloon inflation group. However, blood flow decreased markedly (74-85%) also in the lower brain stem. The results constitute another argument in favour of the Cushing response in supratentorial expansion being caused by ischemia in the brain stem. The critical ischemic region seems to be located rostrally to the oblongate medulla, probably in the pons. (author)

  10. Reproducibility of measuring cerebral blood flow by laser-Doppler flowmetry in mice.

    Science.gov (United States)

    Tajima, Yosuke; Takuwa, Hiroyuki; Kawaguchi, Hiroshi; Masamoto, Kazuto; Ikoma, Yoko; Seki, Chie; Taniguchi, Junko; Kanno, Iwao; Saeki, Naokatsu; Ito, Hiroshi

    2014-01-01

    Laser-Doppler flowmetry has been widely used to trace hemodynamic changes in experimental stroke research. The purpose of the present study was to evaluate the day-to-day test-retest reproducibility of measuring cerebral blood flow by LDF in awake mice. The flux indicating cerebral blood flow (CBF), red blood cell (RBC) velocity, and RBC concentration were measured with LDF via cranial windows for the bilateral somatosensory cortex in awake mice. LDF measurements were performed three times, at baseline, 1 hour after, and 7 days after the baseline measurement. Moreover, breathing rate (BR) and partial pressure of transcutaneous CO₂ (PtCO₂) were measured simultaneously with LDF measurement. Intraclass correlation coefficient (ICC) and within-subject coefficient of variation (CVw) were calculated. CBF, RBC velocity, and RBC concentration showed good day-to-day test-retest reproducibility (ICC: 0.61 - 0.95, CVw: 8.3% - 15.4%). BR and PtCO₂ in awake mice were stable during the course of the experiments. The evaluation of cerebral microcirculation using LDF appears to be applicable to long-term studies. PMID:24389142

  11. Cerebral blood flow, glucose use, and CSF ionic regulation in potassium-depleted rats

    International Nuclear Information System (INIS)

    Rats were kept on a low-K+ diet for 25 or 70 days. Local cerebral blood flow (LCBF) and local cerebral glucose utilization (LCGU) were measured in 31 different structures of the brain by means of the [14C]iodoantipyrine and [14C]2-deoxy-D-glucose method. After 25 and 70 days of K+ depletion LCBF was decreased significantly in 27 and 30 structures, respectively, the average decrease being 19 and 25%. In contrast, average LCGU was not changed. Cisternal cerebrospinal fluid (CSF) K+ concentration decreased significantly from 2.65 ± 0.02 mM in controls to 2.55 ± 0.02 mM and 2.47 ± 0.02 mM in the two treated groups. CSF [HCO3-], pH, and Pco2 were increased in K+-depleted animals. These data show that K+ depletion induces an increase in CSF pH and a decrease in CSF K+ concentration, both of which cause a reduction in cerebral blood flow. The increased CSF Pco2 is secondary to the reduction of blood flow, since brain metabolism and arterial Pco2 remained constant

  12. Multimodal Pressure-Flow Analysis: Application of Hilbert Huang Transform in Cerebral Blood Flow Regulation

    Directory of Open Access Journals (Sweden)

    Vera Novak

    2008-06-01

    Full Text Available Quantification of nonlinear interactions between two nonstationary signals presents a computational challenge in different research fields, especially for assessments of physiological systems. Traditional approaches that are based on theories of stationary signals cannot resolve nonstationarity-related issues and, thus, cannot reliably assess nonlinear interactions in physiological systems. In this review we discuss a new technique called multimodal pressure flow (MMPF method that utilizes Hilbert-Huang transformation to quantify interaction between nonstationary cerebral blood flow velocity (BFV and blood pressure (BP for the assessment of dynamic cerebral autoregulation (CA. CA is an important mechanism responsible for controlling cerebral blood flow in responses to fluctuations in systemic BP within a few heart-beats. The MMPF analysis decomposes BP and BFV signals into multiple empirical modes adaptively so that the fluctuations caused by a specific physiologic process can be represented in a corresponding empirical mode. Using this technique, we showed that dynamic CA can be characterized by specific phase delays between the decomposed BP and BFV oscillations, and that the phase shifts are significantly reduced in hypertensive, diabetics and stroke subjects with impaired CA. Additionally, the new technique can reliably assess CA using both induced BP/BFV oscillations during clinical tests and spontaneous BP/BFV fluctuations during resting conditions.

  13. Screening of specific binding peptide targeting blood vessel of human esophageal cancer in vivo in mice

    Institute of Scientific and Technical Information of China (English)

    ZHI Min; WU Kai-chun; HAO Zhi-ming; GUO Chang-cun; YAO Jia-yin

    2011-01-01

    Background Cancer of the esophagus and gastroesophageal junction remains a virulent malignancy with poor prognosis. Rapid progresses were made in chemotherapeutic agents and the development of molecular markers allowed better identification of candidates for targeted therapy. This study aimed to identify the candidate peptides used for anti-angiogenic therapy of esophageal cancer by in vivo screening C7C peptide library for peptides binding specifically to blood vessels of human esophageal cancer.Methods The phage displayed C7C peptide library was injected intravenously into mice bearing human esophageal tumor xenografts under renal capsule. After 5 rounds of screening, 13 clones were picked up individually and sequenced.During each round of screening, titers of phage recovery were calculated from tumor xenograft and control tissues.Homing of these 9 peptides to tumor vessel was detected by calculating phage titers in the tumor xenograft and control tissues (lung and spleen) after each phage was injected into mice model, and compared with the distribution of phage M13 and Ⅷ-related antigen in tumor xenograft by immunohistochemical staining. Comparisons among groups of data were made using one-way analysis of variance (ANOVA), followed by the Bonferroni multiple comparisons test.Results The number of phage recovered from tumor tissue of each round increased gradually in tumor group while decreased in control groups (P <0.01 in tumor and spleen, P <0.05 in lung). Immunohistochemical staining showed similar staining pattern with M13 antibody or Ⅷ-related antigen antibody, suggesting that phages displaying the selected peptides could home to blood vessel of human esophageal cancer. According to their DNA, 9 corresponding peptide sequences were deduced. And the homing ability to blood vessel of phages displaying the selected peptides was confirmed by comparing with their recovery in tumor and control tissues. Two motifs, YSXNXW and PXNXXN, were also obtained by

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

    OpenAIRE

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

    2012-01-01

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

  15. Measurement of regional cerebral blood flow with H215O positron emission tomography during Matas test - report of three cases

    International Nuclear Information System (INIS)

    The authors carried out a Matas test with a regional cerebral blood flow (rCBF) study using H215O positron emission tomography (PET) for three cases of large internal carotid artery aneurysms. There is a likely correlation between the cerebral blood flow (CBF) reduction rate obtained by PET, and the mean stump pressure available from a conventional balloon occlusion test. The advantages of this noninvasive and quantitative method are presented in comparison with other methods. (author)

  16. Active Path Selection of Fluid Microcapsules in Artificial Blood Vessel by Acoustic Radiation Force

    Science.gov (United States)

    Masuda, Kohji; Muramatsu, Yusuke; Ueda, Sawami; Nakamoto, Ryusuke; Nakayashiki, Yusuke; Ishihara, Ken

    2009-07-01

    Micrometer-sized microcapsules collapse upon exposure to ultrasound. Use of this phenomenon for a drug delivery system (DDS), not only for local delivery of medication but also for gene therapy, should be possible. However, enhancing the efficiency of medication is limited because capsules in suspension diffuse in the human body after injection, since the motion of capsules in blood flow cannot be controlled. To control the behavior of microcapsules, acoustic radiation force was introduced. We detected local changes in microcapsule density by producing acoustic radiation force in an artificial blood vessel. Furthermore, we theoretically estimated the conditions required for active path selection of capsules at a bifurcation point in the artificial blood vessel. We observed the difference in capsule density at both in the bifurcation point and in alternative paths downstream of the bifurcation point for different acoustic radiation forces. Comparing the experimental results with those obtained theoretically, the conditions for active path selection were calculated from the acoustic radiation force and fluid resistance of the capsules. The possibility of controlling capsule flow towards a specific point in a blood vessel was demonstrated.

  17. Threadlike bundle of tubules running inside blood vessels New anatomical structure

    CERN Document Server

    Jiang, X; Shin, H; Lee, B; Choi, C; Soh, K; Cheun, B; Baik, K; Soh, K; Jiang, Xiaowen; Kim, Hee-kyeong; Shin, Hak-soo; Lee, Byong-chon; Choi, Chunho; Soh, Kyung-soon; Cheun, Byeung-soo; Baik, Ku-youn; Soh, Kwang-sup

    2002-01-01

    According to current anatomy, the arteries and veins do not have threadlike structures running inside the vessels. Despite such prevailing knowledge here we report on observation of a novel structure inside the blood vessels of rats and rabbits, which is a semi-transparent elastic bundle of tubules whose diameters are of 10$\\mu$m order. This is a rediscovery of the Bong Han ducts1,2 which have not been confirmed because the observing method was not known. We found a new procedure of observing the intra blood vessel ducts (IBVD) which are too thin, fragile, and semi-transparent to be detected in ordinary surgical operation. The method we contrived is to let blood be coagulated around the IBVD so that they become thick and strong by intravenous injection of 10 per cent dextrose solution at the vena femoralis. A piece of thickened IBVD sample is treated with urokinase to remove blood clots and the thin thread of IBVD is embedded inside of a string of fibrin

  18. Cerebrolysin effects on neurological outcomes and cerebral blood flow in acute ischemic stroke

    Science.gov (United States)

    Amiri-Nikpour, Mohammad Reza; Nazarbaghi, Surena; Ahmadi-Salmasi, Babak; Mokari, Tayebeh; Tahamtan, Urya; Rezaei, Yousef

    2014-01-01

    Background Cerebrolysin, a brain-derived neuropeptide, has been shown to improve the neurological outcomes of stroke, but no study has demonstrated its effect on cerebral blood flow. This study aimed to determine the cerebrolysin impact on the neurological outcomes and cerebral blood flow. Methods In a randomized, double-blinded, placebo-controlled trial, 46 patients who had acute focal ischemic stroke were randomly assigned into two groups to receive intravenously either 30 mL of cerebrolysin diluted in normal saline daily for 10 days (n=23) or normal saline alone (n=23) adjunct to 100 mg of aspirin daily. All patients were examined using the National Institutes of Health Stroke Scale and transcranial Doppler to measure the mean flow velocity and pulsatility index (PI) of their cerebral arteries at baseline as well as on days 30, 60, and 90. Results The patients’ mean age was 60±9.7 years, and 51.2% of patients were male. The National Institutes of Health Stroke Scale was significantly lower in the cerebrolysin group compared with the placebo group on day 60 (median 10, interquartile range 9–11, P=0.008) and day 90 (median 11, interquartile range 10–13.5, P=0.001). The median of PI in the right middle cerebral artery was significantly lower in the cerebrolysin group compared with the placebo group on days 30, 60, and 90 (P<0.05). One patient in the cerebrolysin group and two patients in the placebo group died before day 30 (4.3% versus 8.7%). Conclusion Cerebrolysin can be useful to improve the neurological outcomes and the PI of middle cerebral artery in patients with acute focal ischemic stroke. PMID:25516711

  19. Changes in human cerebral blood flow and myocardial blood flow during mental stress measured by dual positron emission tomography

    International Nuclear Information System (INIS)

    Mental stress causes a substantial sympathetic response, thus increasing myocardial blood flow (MBF). However, the effects of mental stress on global cerebral blood flow (CBF) have not been elucidated. In this study, changes in CBF and MBF in relation to mental stress were measured by a dual positron emission tomography system that can measure CBF and MBF simultaneously. CBF and MBF were measured in 10 healthy men with O-15 labeled water at rest (baseline) and during the performance of a mental task that required subtraction of 7s serially from a four-digit number. Baseline global CBF and values obtained during the mental activity were 0.42±0.05 and 0.45±0.06 ml/ml/min (mean±SD), respectively. Baseline MBF and values obtained during mental activity were 0.61±0.12 and 1.09±0.58 ml/ml/min, respectively. Percent changes in CBF and MBF during mental stress were 6±11% and 78±73%, respectively. No significant difference was observed in arterial carbon dioxide tension (PaCO2) level between the mental stress and baseline conditions. MBF, blood pressure, heart rate, and plasma concentrations of adrenaline and noradrenaline increased significantly during mental stress. Sympathetic stimulation is reported to cause cerebral vasoconstriction and reduce CBF in animals. Although such a sympathetic response was observed in relation to mental stress, no significant change in CBF was observed in our subjects. (author)

  20. "Sausage-string" appearance of arteries and arterioles can be caused by an instability of the blood vessel wall

    DEFF Research Database (Denmark)

    Jacobsen, Jens Christian Brings; Beierholm, Ulrik; Mikkelsen, Rene;

    2002-01-01

    observed experimentally. Most importantly, it suggests that the "sausaging" phenomenon is neither caused by a mechanical failure of the vessel wall due to a high blood pressure nor is it due to standing pressure waves caused by the beating of the heart. Rather, it is the expression of a general instability......Vascular damage induced by acute hypertension is preceded by a peculiar pattern where blood vessels show alternating regions of constrictions and dilations ("sausages on a string"). The pattern occurs in the smaller blood vessels, and it plays a central role in causing the vascular damage. A...... related vascular pattern has been observed in larger vessels from several organs during angiography. In the larger vessels the occurrence of the pattern does not appear to be related to acute hypertension. A unifying feature between the phenomenon in large and small vessels seems to be an increase in...