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Brain blood flow

Stephen B Hladky, Margery A Barrand
This review considers efflux of substances from brain parenchyma quantified as values of clearances (CL, stated in µL g-1  min-1 ). Total clearance of a substance is the sum of clearance values for all available routes including perivascular pathways and the blood-brain barrier. Perivascular efflux contributes to the clearance of all water-soluble substances. Substances leaving via the perivascular routes may enter cerebrospinal fluid (CSF) or lymph. These routes are also involved in entry to the parenchyma from CSF...
October 19, 2018: Fluids and Barriers of the CNS
Shouping Hu, Qiang Liu, Sufang Zang, Zhuo Zhang, Jingfei Wang, Xuehui Cai, Xijun He
Pseudorabies virus (PRV) can spread along the peripheral nerves near the site of infection in the animals, and gradually migrates into the central nervous system, where it leads to the development of brain lesions. The aim of this study was to investigate the dynamics of microglia after PRV inoculation. A mouse model inoculated with PRV was established to study the interactions between PRV and microglia, microglial recruitment, and polarization effects. The mice were subcutaneously inoculated with different doses of PRV-Bartha K61 vaccine strain...
October 19, 2018: Viral Immunology
Ryosuke Mihara, Akira Takasu, Kentaro Maemura, Toshiaki Minami
Aim: To examine whether prolonged hemorrhagic shock (HS) at a mean arterial pressure (MAP) of 40 mmHg leads to brain damage. Methods: Rats were anesthetized with sevoflurane. The HS model consisted of the following phases: I, pressure-controlled HS at a MAP of 40 mmHg; II, fluid resuscitation to normalize blood pressure; III, observations with outcome evaluations in terms of survival, overall performance categories, and neurological deficit scores, as well as evaluation of apoptosis in the hippocampus at 96 h...
October 2018: Acute Medicine & Surgery
Farzaneh Atashrazm, Deborah Hammond, Gayathri Perera, Carol Dobson-Stone, Nicole Mueller, Russell Pickford, Woojin Scott Kim, John B Kwok, Simon J G Lewis, Glenda M Halliday, Nicolas Dzamko
Missense mutations in glucocerebrosidase (GBA1) that impair the activity of the encoded lysosomal lipid metabolism enzyme (GCase) are linked to an increased risk of Parkinson's disease. However, reduced GCase activity is also found in brain tissue from Parkinson's disease patients without GBA1 mutations, implicating GCase dysfunction in the more common idiopathic form of Parkinson's disease. GCase is very highly expressed in monocytes, and thus we measured GCase activity in blood samples from recently diagnosed Parkinson's disease patients...
October 18, 2018: Scientific Reports
Takeshi Kondo, Yo Niida, Masashi Mizuguchi, Yasushi Nagasaki, Yasuhiro Ueno, Akiyoshi Nishimura
Tuberous sclerosis complex (TSC) is a genetic multisystem disorder characterized by widespread hamartomas in several organs, including the brain, heart, skin, eyes, kidney, lung, and liver. Rhabdomyoma is the most common cardiac tumor diagnosed in fetuses, neonates and infants, and is closely linked to TSC. Here we describe an autopsy case of right ventricular rhabdomyoma in TSC. The deceased was a 3-month-old male infant, and TSC with a cardiac tumor had been diagnosed before his death. Since the cardiac tumor had not been physically blocking the blood flow, he had not undergone surgical intervention...
October 9, 2018: Legal Medicine
Michał Elwertowski, Jerzy Leszczyński, Piotr Kaszczewski, Krzysztof Lamparski, Stella Sin Yee Ho, Zbigniew Gałązka
AIM: An assessment of increased compensatory blood flow in the brain-supplying arteries in patients with significant carotid artery stenosis. MATERIALS AND METHODS: Doppler ultrasound was performed in 218 patients over 60 years of age to evaluate both the degree of brain-supplying artery stenosis as well as the blood flow volume balance in all vessels supplying the brain: the internal carotid artery, the external carotid artery and the vertebral artery. The control group included 94 patients with no stenosis in the extracranial segments and no neurological manifestations, in whom blood flow values were calculated (the internal carotid artery - 290 mL/min, the external carotid artery - 125 mL/min, the vertebral artery - 80 mL/min); the total mean blood flow in the brain-supplying arteries was 985 mL/min...
2018: Journal of Ultrasonography
Gina Hadley, Daniel J Beard, Yvonne Couch, Ain A Neuhaus, Bryan A Adriaanse, Gabriele C DeLuca, Brad A Sutherland, Alastair M Buchan
The significant morbidity that accompanies stroke makes it one of the world's most devastating neurological disorders. Currently, proven effective therapies have been limited to thrombolysis and thrombectomy. The window for the administration of these therapies is narrow, hampered by the necessity of rapidly imaging patients. A therapy that could extend this window by protecting neurons may improve outcome. Endogenous neuroprotection has been shown to be, in part, due to changes in mTOR signalling pathways and the instigation of productive autophagy...
October 18, 2018: Journal of Cerebral Blood Flow and Metabolism
Eugene A Kiyatkin
The goal of this work is to consider physiological fluctuations in brain oxygen levels and its changes induced by opioid drugs. This review article presents, as a comprehensive story, the most important findings obtained in our laboratory by using high-speed amperometry with oxygen sensors in awake, freely moving rats; most of these findings were separately published elsewhere. First, we show that oxygen levels in the nucleus accumbens (NAc) phasically increase following exposure to natural arousing stimuli...
2018: Frontiers in Integrative Neuroscience
Osman Shabir, Jason Berwick, Sheila E Francis
Efficient blood supply to the brain is of paramount importance to its normal functioning and improper blood flow can result in potentially devastating neurological consequences. Cerebral blood flow in response to neural activity is intrinsically regulated by a complex interplay between various cell types within the brain in a relationship termed neurovascular coupling. The breakdown of neurovascular coupling is evident across a wide variety of both neurological and psychiatric disorders including Alzheimer's disease...
October 17, 2018: BMC Neuroscience
Jonathan Doucette, Luxi Wei, Enedino Hernández-Torres, Christian Kames, Nils D Forkert, Rasmus Aamand, Torben E Lund, Brian Hansen, Alexander Rauscher
Blood vessel related magnetic resonance imaging (MRI) contrast provides a window into the brain's metabolism and function. Here, we show that the spin echo dynamic susceptibility contrast (DSC) MRI signal of the brain's white matter (WM) strongly depends on the angle between WM tracts and the main magnetic field. The apparent cerebral blood flow and volume are 20% larger in fibres perpendicular to the main magnetic field compared to parallel fibres. We present a rapid numerical framework for the solution of the Bloch-Torrey equation that allows us to explore the isotropic and anisotropic components of the vascular tree...
October 14, 2018: NeuroImage
Danilo Cardim, Chiara Robba, Basil Matta, Graham Tytherleigh-Strong, Niel Kang, Bernhard Schmidt, Joseph Donnelly, Leanne Calviello, Peter Smielewski, Marek Czosnyka
Although the beach-chair position (BCP) is widely used during shoulder surgery, it has been reported to associate with a reduction in cerebral blood flow, oxygenation, and risk of brain ischaemia. We assessed cerebral haemodynamics using a multiparameter transcranial Doppler-derived approach in patients undergoing shoulder surgery. 23 anaesthetised patients (propofol (2 mg/kg)) without history of neurologic pathology undergoing elective shoulder surgery were included. Arterial blood pressure (ABP, monitored with a finger-cuff plethysmograph calibrated at the auditory meatus level) and cerebral blood flow velocity (FV, monitored in the middle cerebral artery) were recorded in supine and in BCP...
October 17, 2018: Journal of Clinical Monitoring and Computing
Haitang Qiu, Xinke Li, Qinghua Luo, Yongming Li, Xichuan Zhou, Hailin Cao, Yuanhong Zhong, Mingui Sun
BACKGROUND: Electroconvulsive therapy (ECT) is an important treatment option for patients with major depressive disorder (MDD). However, the mechanisms of ECT in MDD are still unclear. METHODS: Twenty-four patients with severe MDD and 14 healthy controls were enrolled in this study. Eight ECT sessions were conducted for MDD patients using brief-pulse square-wave signal at bitemporal locations. To investigate the regional cerebral blood flow in MDD patients before and after ECT treatments by resting-state functional magnetic resonance imaging (rs-fMRI), the patients were scanned twice (before the first ECT and after the eighth ECT) for data acquisition...
October 9, 2018: Journal of Affective Disorders
Meher R Juttukonda, Chelsea A Lee, Niral J Patel, Larry T Davis, Spencer L Waddle, Melissa C Gindville, Sumit Pruthi, Adetola A Kassim, Michael R DeBaun, Manus J Donahue, Lori C Jordan
BACKGROUND: Blood transfusions are administered to children and adults with sickle cell anemia (SCA) for secondary stroke prevention, or as treatment for recurrent pain crises or acute anemia, but transfusion effects on cerebral hemodynamics and metabolism are not well-characterized. PURPOSE: To compare blood transfusion-induced changes in hemometabolic parameters, including oxygen extraction fraction (OEF) and cerebral blood flow (CBF), within and between adults and children with SCA...
October 15, 2018: Journal of Magnetic Resonance Imaging: JMRI
Leon M T Dicks, Leané Dreyer, Carine Smith, Anton D van Staden
The intestinal barrier, consisting of the vascular endothelium, epithelial cell lining, and mucus layer, covers a surface of about 400 m2 . The integrity of the gut wall is sustained by transcellular proteins forming tight junctions between the epithelial cells. Protected by three layers of mucin, the gut wall forms a non-permeable barrier, keeping digestive enzymes and microorganisms within the luminal space, separate from the blood stream. Microorganisms colonizing the gut may produce bacteriocins in an attempt to outcompete pathogens...
2018: Frontiers in Microbiology
Andreas Hartmann, Jay P Mohr
Given the need for early restoration of blood flow and preservation of partially damaged brain cells after ischemic stroke, the noninterventional treatment of stroke relies heavily on the speedy recognition and classification of the clinical syndrome. Initiation of systemic thrombolysis with careful observation of contraindications within the 3.0 (4.5)-hour time window is the approved therapy of choice. Management of hemorrhagic complications and resumption of oral anticoagulation if indicated are also discussed in this article...
November 2018: Neuroimaging Clinics of North America
Lotfi Hacein-Bey, Jeremy J Heit, Angelos A Konstas
Restoration of cerebral blood flow is the most important step in preventing irreversible damage to hypoperfused brain cells after ischemic stroke from large-vessel occlusion. For those patients who do not respond to (or are not eligible for) intravenous thrombolysis, endovascular therapy has become standard of care. A shift is currently taking place from rigid time windows for intervention (time is brain) to physiology-driven paradigms that rely heavily on neuroimaging. At this time, one can reasonably anticipate that more patients will be treated, and that outcomes will keep improving...
November 2018: Neuroimaging Clinics of North America
Jeremy J Heit, Greg Zaharchuk, Max Wintermark
Acute ischemic stroke (AIS) occurs when there is a sudden loss in cerebral blood flow due to embolic or thromboembolic occlusion of a cerebral or cervical artery. Patients with AIS require emergent neuroimaging to guide treatment, which includes intravenous thrombolysis and endovascular mechanical thrombectomy (EMT). Recent advances in AIS treatment by EMT has been driven in part by advances in computed tomography (CT) and MR imaging neuroimaging evaluation of ischemic penumbra and pial collateral vessels. The authors review advanced noninvasive brain imaging by CT and MR imaging for the evaluation of AIS focusing on penumbral and collateral imaging...
November 2018: Neuroimaging Clinics of North America
Baijayanta Maiti, Joel S Perlmutter
Positron emission tomography (PET) has revealed key insights into the pathophysiology of movement disorders. This paper will focus on how PET investigations of pathophysiology are particularly relevant to Parkinson disease, a neurodegenerative condition usually starting later in life marked by a varying combination of motor and nonmotor deficits. Various molecular imaging modalities help to determine what changes in brain herald the onset of pathology; can these changes be used to identify presymptomatic individuals who may be appropriate for to-be-developed treatments that may forestall onset of symptoms or slow disease progression; can PET act as a biomarker of disease progression; can molecular imaging help enrich homogenous cohorts for clinical studies; and what other pathophysiologic mechanisms relate to nonmotor manifestations...
November 2018: Seminars in Nuclear Medicine
Nathan P Cramer, Alexandru Korotcov, Asamoah Bosomtwi, Xiufen Xu, Derek Holman, Kathleen Whiting, Scott Jones, Andrew Hoy, Bernard J Dardzinski, Zygmunt Galdzicki
We sought to understand the mechanisms underlying cognitive deficits that are reported to affect non-native subjects following their prolonged stay and/or work at high altitude (HA). We found that mice exposed to a simulated environment of 5000 m exhibit deficits in hippocampal learning and memory accompanied by abnormalities in brain MR imaging. Exposure (1-8 months) to HA led to an increase in brain ventricular volume, a reduction in relative cerebral blood flow and changes in diffusion tensor imaging (DTI) derived parameters within the hippocampus and corpus callosum...
October 12, 2018: Experimental Neurology
Da Chang, Jian Zhang, Wei Peng, Zhuowen Shen, Xin Gao, Youhong Du, Qiu Ge, Donghui Song, Yuanqi Shang, Ze Wang
Chronic smoking impairs brain functions in the prefrontal cortex and the projecting meso-cortical limbic system. The purpose of this pilot study is to examine whether modulating the frontal brain activity using high-frequency repetitive transcranial magnetic stimulation (rTMS) can improve smoking cessation and to explore the changing pattern of the brain activity after treatment. Fourteen treatment-seeking smokers were offered a program involving 10 days of rTMS treatment with a follow-up for another 25 days...
2018: Frontiers in Human Neuroscience
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