scholarly journals The interplay of blood flow and temperature in regional hyperthermia: a mathematical approach

2021 ◽  
Vol 8 (1) ◽  
pp. 201234
Author(s):  
Jesús J. Bosque ◽  
Gabriel F. Calvo ◽  
Víctor M. Pérez-García ◽  
María Cruz Navarro
Keyword(s):  
Blood Flow ◽  
Brain Tumours ◽  
Adjuvant Radiotherapy ◽  
Current Knowledge ◽  
Future Research ◽  
Mathematical Approach ◽  
Regional Hyperthermia ◽  
Therapeutic Modalities ◽  
Temperature Levels ◽  
The Brain

In recent decades, hyperthermia has been used to raise oxygenation levels in tumours undergoing other therapeutic modalities, of which radiotherapy is the most prominent one. It has been hypothesized that oxygenation increases would come from improved blood flow associated with vasodilation. However, no test has determined whether this is a relevant assumption or other mechanisms might be acting. Additionally, since hyperthermia and radiotherapy are not usually co-administered, the crucial question arises as to how temperature and perfusion in tumours will change during and after hyperthermia. Overall, it would seem necessary to find a research framework that clarifies the current knowledge, delimits the scope of the different effects and guides future research. Here, we propose a simple mathematical model to account for temperature and perfusion dynamics in brain tumours subjected to regional hyperthermia. Our results indicate that tumours in well-perfused organs like the brain might only reach therapeutic temperatures if their vasculature is highly disrupted. Furthermore, the characteristic times of return to normal temperature levels are markedly shorter than those required to deliver adjuvant radiotherapy. According to this, a mechanistic coupling of perfusion and temperature would not explain any major oxygenation boost in brain tumours immediately after hyperthermia.

scholarly journals Adenosine A2AReceptors in Substance Use Disorders: A Focus on Cocaine

Cells ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 1372 ◽  
Author(s):  
Karolina Wydra ◽  
Dawid Gawliński ◽  
Kinga Gawlińska ◽  
Małgorzata Frankowska ◽  
Dasiel O. Borroto-Escuela ◽  
...  
Keyword(s):  
Substance Use ◽  
Substance Use Disorders ◽  
Current Knowledge ◽  
Ex Vivo ◽  
D2 Receptors ◽  
Future Research ◽  
Receptor Complexes ◽  
Abused Drugs ◽  
The Brain

Several psychoactive drugs can evoke substance use disorders (SUD) in humans and animals, and these include psychostimulants, opioids, cannabinoids (CB), nicotine, and alcohol. The etiology, mechanistic processes, and the therapeutic options to deal with SUD are not well understood. The common feature of all abused drugs is that they increase dopamine (DA) neurotransmission within the mesocorticolimbic circuitry of the brain followed by the activation of DA receptors. D2 receptors were proposed as important molecular targets for SUD. The findings showed that D2 receptors formed heteromeric complexes with other GPCRs, which forced the addiction research area in new directions. In this review, we updated the view on the brain D2 receptor complexes with adenosine (A)2A receptors (A2AR) and discussed the role of A2AR in different aspects of addiction phenotypes in laboratory animal procedures that permit the highly complex syndrome of human drug addiction. We presented the current knowledge on the neurochemical in vivo and ex vivo mechanisms related to cocaine use disorder (CUD) and discussed future research directions for A2AR heteromeric complexes in SUD.

Swearing and the brain

2018 ◽  
pp. 107-139 ◽  
Author(s):  
Shlomit Ritz Finkelstein
Keyword(s):  
Alzheimer’S Disease ◽  
Tourette Syndrome ◽  
Clinical Data ◽  
Brain Injuries ◽  
Current Knowledge ◽  
Brain Regions ◽  
Future Research ◽  
Social Inhibition ◽  
Previous Knowledge ◽  
The Brain

This chapter explores and summarizes the current knowledge about the neurophysiological substrata of the utterance of expletives—its brain regions, pathways, and neurotransmitters, and its interaction with hormones. The chapter presents clinical data that have been gathered directly from patients of aphasia, Tourette syndrome, Alzheimer’s disease, and brain injuries—all are disorders often accompanied with expletives. It also discusses the possible relations between swearing and aggression, swearing and pain, and swearing and social inhibition in the population at large. Finally, the chapter examines the clinical data and the data gathered from the population at large within one frame, and proposes two hypotheses that can serve as possible directions for future research about the biological substrata of swearing. No previous knowledge of the brain is assumed.

scholarly journals Neurotropic Astroviruses in Animals

Viruses ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1201
Author(s):  
Nicole Wildi ◽  
Torsten Seuberlich
Keyword(s):  
Current Knowledge ◽  
Animal Health ◽  
Circulatory System ◽  
Future Research ◽  
Neuronal Necrosis ◽  
Ruminant Species ◽  
Research Activities ◽  
Viral Determinants ◽  
Suppurative Inflammation ◽  
The Brain

Astrovirus infections are among the main causes of diarrhea in children, but their significance for animal health has remained underestimated and largely unknown. This is changing due to the increasing amount of newly identified neurotropic astroviruses in cases of nonsuppurative encephalitis and neurological disease in humans, pigs, ruminant species and minks. Neurological cases in ruminants and humans usually occur sporadically and as isolated cases. This contrasts with the situation in pigs and minks, in which diseases associated with neurotropic astroviruses are endemic and occur on the herd level. Affected animals show neurological signs such as mild ataxia to tetraplegia, loss of orientation or trembling, and the outcome is often fatal. Non-suppurative inflammation with perivascular cuffing, gliosis and neuronal necrosis are typical histological lesions of astrovirus encephalitis. Since astroviruses primarily target the gastrointestinal tract, it is assumed that they infect the brain through the circulatory system or retrograde following the nerves. The phylogenetic analysis of neurotropic astroviruses has revealed that they are genetically closely related, suggesting the presence of viral determinants for tissue tropism and neuroinvasion. In this review, we summarize the current knowledge on neurotropic astrovirus infections in animals and propose future research activities.

scholarly journals Evidence for intranasal oxytocin delivery to the brain: recent advances and future perspectives

2018 ◽  
Author(s):  
Daniel Quintana ◽  
Knut T. Smerud ◽  
Ole A. Andreassen ◽  
Per G. Djupesland
Keyword(s):  
Social Behavior ◽  
Animal Studies ◽  
Current Knowledge ◽  
Central Compartment ◽  
Olfactory Nerve ◽  
Future Research ◽  
Psychiatric Illnesses ◽  
Non Invasive ◽  
Oxytocin Receptors ◽  
The Brain

The neuropeptide oxytocin plays an evolutionarily conserved role in mammalian social behavior. To experimentally manipulate central levels of oxytocin, animal studies have adopted direct intracerebroventricular (ICV) delivery to the brain, given that only small amounts of peripherally circulating oxytocin are thought to transfer from the periphery to the central compartment. Despite striking effects on social behavior in animals, ICV drug delivery is largely impractical for human therapies. Intranasal oxytocin delivery provides a non-invasive alternative to increase central oxytocin activity, and has shown promise as a treatment for psychiatric illnesses characterized by social dysfunction. Intranasal oxytocin delivery is purported to increase central oxytocin concentrations via channels surrounding trigeminal and olfactory nerve fibres, which may facilitate increased activity at central oxytocin receptors. This review outlines the evidence for intranasal oxytocin delivery increasing central concentrations or activity, identifies current knowledge gaps, and highlights future research opportunities. Recent efforts to enhance intranasal oxytocin delivery via improved intranasal delivery technology and dose-ranging studies are also discussed.

scholarly journals Topology and Hemodynamics of the Cortical Cerebrovascular System

2012 ◽  
Vol 32 (6) ◽  
pp. 952-967 ◽  
Author(s):  
Sven Hirsch ◽  
Johannes Reichold ◽  
Matthias Schneider ◽  
Gábor Székely ◽  
Bruno Weber
Keyword(s):  
Blood Flow ◽  
Vascular System ◽  
Current Knowledge ◽  
Energy Requirement ◽  
Vascular Anatomy ◽  
Neuronal Loss ◽  
Energy Substrates ◽  
Detailed Understanding ◽  
Cerebrovascular System ◽  
The Brain

The cerebrovascular system continuously delivers oxygen and energy substrates to the brain, which is one of the organs with the highest basal energy requirement in mammals. Discontinuities in the delivery lead to fatal consequences for the brain tissue. A detailed understanding of the structure of the cerebrovascular system is important for a multitude of (patho-)physiological cerebral processes and many noninvasive functional imaging methods rely on a signal that originates from the vasculature. Furthermore, neurodegenerative diseases often involve the cerebrovascular system and could contribute to neuronal loss. In this review, we focus on the cortical vascular system. In the first part, we present the current knowledge of the vascular anatomy. This is followed by a theory of topology and its application to vascular biology. We then discuss possible interactions between cerebral blood flow and vascular topology, before summarizing the existing body of the literature on quantitative cerebrovascular topology.

scholarly journals The Role of Lymphatic Marker Prox-1 in Relation to Brain Tumours

2021 ◽  
Vol 65 (4) ◽  
pp. 72-78
Author(s):  
J. Teleky ◽  
J. Király
Keyword(s):  
Brain Tumours ◽  
Current Knowledge ◽  
Treatment Options ◽  
Lymphatic Vessels ◽  
Homeobox Gene ◽  
Lymphatic Vasculature ◽  
Lymphatic Development ◽  
The Central Nervous System ◽  
The Brain

Abstract The homeobox gene, Prox-1 is a transcription factor essential for lymphatic development (lymphangiogenesis) during embryogenesis. It also performs different functions in various tissues such as: retina, lens, liver, pancreas and the central nervous system. Intense expression of Prox-1 has been demonstrated in the developing spinal cord and brain. In adulthood its expression continues in the hippocampus and cerebellum. In adult tissues the process of lymphatic vasculature formation is accompanied under certain pathological conditions such as inflammation, tissue repair and tumour growth. Prox-1 expression is typical for lymphatic vessels; thus it belongs to one of the most specific and widely used mammalian lymphatic endothelial marker in the detection of lymphangiogenesis and lymphatic vessel invasion in oncogenesis. It has been shown that Prox-1 is involved in cancer development and progression. It’s tumour suppressive and oncogenic properties are proven in several human cancers, including brain tumours. Among all body cancers the brain tumours represent the most feared tumours with very limited treatment options and a poor diagnosis. The aim of this paper was to show the current knowledge of the gene Prox-1 with an emphasis on brain tumours, especially in gliomas.

Microvascular features that suggest effectors of blood-flow regulation in the brain: Evidence by SEM of corrosion casts of intracerebral vessels

1990 ◽  
Vol 48 (3) ◽  
pp. 274-275
Author(s):  
Enrico D.F. Motti ◽  
Hans-Georg Imhof ◽  
Gazi M. Yasargil
Keyword(s):  
Blood Flow ◽  
Perfusion Pressure ◽  
Corrosion Casts ◽  
Cerebral Microcirculation ◽  
Pial Arteries ◽  
Random Occurrence ◽  
Brain Arteries ◽  
Homogeneous Network ◽  
The Brain

Physiologists have devoted most attention in the cerebrovascular tree to the arterial side of the circulation which has been subdivided in three levels: 1) major brain arteries which keep microcirculation constant despite changes in perfusion pressure; 2) pial arteries supposed to be effectors regulating microcirculation; 3) intracerebral arteries supposed to be deprived of active cerebral blood flow regulating devices.The morphological search for microvascular effectors in the cerebrovascular bed has been elusive. The opaque substance of the brain confines in vivo investigation to the superficial pial arteries. Most morphologists had to limit their observation to the random occurrence of a favorable site in the practically two-dimensional thickness of diaphanized histological sections. It is then not surprising most investigators of the cerebral microcirculation refer to an homogeneous network of microvessels interposed between arterioles and venules.We have taken advantage of the excellent depth of focus afforded by the scanning electron microscope (SEM) to investigate corrosion casts obtained injecting a range of experimental animals with a modified Batson's acrylic mixture.

Fit Vs Faint: Assessing Work Causation in “Idiopathic Fall” Cases

2014 ◽  
Vol 19 (5) ◽  
pp. 3-12
Author(s):  
Lorne Direnfeld ◽  
David B. Torrey ◽  
Jim Black ◽  
LuAnn Haley ◽  
Christopher R. Brigham
Keyword(s):  
Blood Flow ◽  
Electrical Activity ◽  
Loss Of Consciousness ◽  
Brain Electrical Activity ◽  
Medical Terminology ◽  
Scientific Analysis ◽  
Medical Causation ◽  
The Individual ◽  
The Brain ◽  
Current Science

Abstract When an individual falls due to a nonwork-related episode of dizziness, hits their head and sustains injury, do workers’ compensation laws consider such injuries to be compensable? Bearing in mind that each state makes its own laws, the answer depends on what caused the loss of consciousness, and the second asks specifically what happened in the fall that caused the injury? The first question speaks to medical causation, which applies scientific analysis to determine the cause of the problem. The second question addresses legal causation: Under what factual circumstances are injuries of this type potentially covered under the law? Much nuance attends this analysis. The authors discuss idiopathic falls, which in this context means “unique to the individual” as opposed to “of unknown cause,” which is the familiar medical terminology. The article presents three detailed case studies that describe falls that had their genesis in episodes of loss of consciousness, followed by analyses by lawyer or judge authors who address the issue of compensability, including three scenarios from Arizona, California, and Pennsylvania. A medical (scientific) analysis must be thorough and must determine the facts regarding the fall and what occurred: Was the fall due to a fit (eg, a seizure with loss of consciousness attributable to anormal brain electrical activity) or a faint (eg, loss of consciousness attributable to a decrease in blood flow to the brain? The evaluator should be able to fully explain the basis for the conclusions, including references to current science.

Basic Ideas and Principles for Quantifying Regional Blood Flow with Nuclear Medical Techniques

1996 ◽  
Vol 35 (05) ◽  
pp. 181-185 ◽  
Author(s):  
H. Herzog
Keyword(s):  
Blood Flow ◽  
Nuclear Medicine ◽  
Regional Blood Flow ◽  
Visual Presentation ◽  
Regional Cerebral Blood ◽  
Basic Principles ◽  
Parametric Images ◽  
Major Application ◽  
Basic Ideas ◽  
The Brain

SummaryThe measurement of blood flow in various organs and its visual presentation in parametric images is a major application in nuclear medicine. The purpose of this paper is to summarize the most important nuclear medicine procedures used to quantify regional blood flow. Starting with the first concepts introduced by Fick and later by Kety-Schmidt the basic principles of measuring global and regional cerebral blood are discussed and their relationships are explained. Different applications and modifications realized first in PET- and later in SPECT-studies of the brain and other organs are described. The permeability and the extraction of the different radiopharmaceuticals are considered. Finally some important instrumental implications are compared.

Vorläufige Ergebnisse von 99mTc-HMPAO-SPECT-Untersuchungen bei endogenen Psychosen

1989 ◽  
Vol 28 (03) ◽  
pp. 88-91
Author(s):  
J. Schröder ◽  
H. Henningsen ◽  
H. Sauer ◽  
P. Georgi ◽  
K.-R. Wilhelm
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Regional Cerebral Blood Flow ◽  
Regions Of Interest ◽  
Post Mortem ◽  
Regional Cerebral Blood ◽  
Hmpao Spect ◽  
Endogenous Psychoses ◽  
The Brain ◽  
99Mtc Hmpao

18 psychopharmacologically treated patients (7 schizophrenics, 5 schizoaffectives, 6 depressives) were studied using 99mTc-HMPAO-SPECT of the brain. The regional cerebral blood flow was measured in three transversal sections (infra-/supraventricular, ventricular) within 6 regions of interest (ROI) respectively (one frontal, one parietal and one occipital in each hemisphere). Corresponding ROIs of the same section in each hemisphere were compared. In the schizophrenics there was a significantly reduced perfusion in the left frontal region of the infraventricular and ventricular section (p < 0.02) compared with the data of the depressives. The schizoaffectives took an intermediate place. Since the patients were treated with psychopharmaca, the result must be interpreted cautiously. However, our findings seem to be in accordance with post-mortem-, CT- and PET-studies presented in the literature. Our results suggest that 99mTc-HMPAO-SPECT may be helpful in finding cerebral abnormalities in endogenous psychoses.

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