Dielectric properties of dog brain tissue measured in vitro across the 0.3-3 GHz band

2016 ◽  
Vol 37 (8) ◽  
pp. 549-556 ◽  
Author(s):  
Beadaa Mohammed ◽  
Konstanty Bialkowski ◽  
Amin Abbosh ◽  
Paul C. Mills ◽  
Andrew P. Bradley
Keyword(s):  
Dielectric Properties ◽  
Brain Tissue ◽  
Dog Brain

Monocytes as Carriers of Magnetic Nanoparticles for Tracking Inflammation in the Epileptic Rat Brain

2019 ◽  
Vol 16 (7) ◽  
pp. 637-644 ◽  
Author(s):  
Hadas Han ◽  
Sara Eyal ◽  
Emma Portnoy ◽  
Aniv Mann ◽  
Miriam Shmuel ◽  
...  
Keyword(s):  
Brain Tissue ◽  
Ex Vivo ◽  
In Vivo Studies ◽  
Nanoparticle Distribution ◽  
Spontaneous Seizures ◽  
Systemic Distribution ◽  
Hippocampal Ca1 ◽  
Pilocarpine Model

Background: Inflammation is a hallmark of epileptogenic brain tissue. Previously, we have shown that inflammation in epilepsy can be delineated using systemically-injected fluorescent and magnetite- laden nanoparticles. Suggested mechanisms included distribution of free nanoparticles across a compromised blood-brain barrier or their transfer by monocytes that infiltrate the epileptic brain. Objective: In the current study, we evaluated monocytes as vehicles that deliver nanoparticles into the epileptic brain. We also assessed the effect of epilepsy on the systemic distribution of nanoparticleloaded monocytes. Methods: The in vitro uptake of 300-nm nanoparticles labeled with magnetite and BODIPY (for optical imaging) was evaluated using rat monocytes and fluorescence detection. For in vivo studies we used the rat lithium-pilocarpine model of temporal lobe epilepsy. In vivo nanoparticle distribution was evaluated using immunohistochemistry. Results: 89% of nanoparticle loading into rat monocytes was accomplished within 8 hours, enabling overnight nanoparticle loading ex vivo. The dose-normalized distribution of nanoparticle-loaded monocytes into the hippocampal CA1 and dentate gyrus of rats with spontaneous seizures was 176-fold and 380-fold higher compared to the free nanoparticles (p<0.05). Seizures were associated with greater nanoparticle accumulation within the liver and the spleen (p<0.05). Conclusion: Nanoparticle-loaded monocytes are attracted to epileptogenic brain tissue and may be used for labeling or targeting it, while significantly reducing the systemic dose of potentially toxic compounds. The effect of seizures on monocyte biodistribution should be further explored to better understand the systemic effects of epilepsy.

scholarly journals In Vivo and In Vitro Toxicodynamic Analyses of New Quinolone-and Nonsteroidal Anti-Inflammatory Drug-Induced Effects on the Central Nervous System

1999 ◽  
Vol 43 (5) ◽  
pp. 1091-1097 ◽  
Author(s):  
Hideki Kita ◽  
Hirotami Matsuo ◽  
Hitomi Takanaga ◽  
Junichi Kawakami ◽  
Koujirou Yamamoto ◽  
...  
Keyword(s):  
Brain Tissue ◽  
Threshold Concentration ◽  
Current Response ◽  
Drug Induced ◽  
Inhibition Ratio ◽  
New Quinolones ◽  
The Central Nervous System ◽  
Anti Inflammatory

ABSTRACT We investigated the correlation between an in vivo isobologram based on the concentrations of new quinolones (NQs) in brain tissue and the administration of nonsteroidal anti-inflammatory drugs (NSAIDs) for the occurrence of convulsions in mice and an in vitro isobologram based on the concentrations of both drugs for changes in the γ-aminobutyric acid (GABA)-induced current response in Xenopus oocytes injected with mRNA from mouse brains in the presence of NQs and/or NSAIDs. After the administration of enoxacin (ENX) in the presence or absence of felbinac (FLB), ketoprofen (KTP), or flurbiprofen (FRP), a synergistic effect was observed in the isobologram based on the threshold concentration in brain tissue between mice with convulsions and those without convulsions. The three NSAIDs did not affect the pharmacokinetic behavior of ENX in the brain. However, the ENX-induced inhibition of the GABA response in the GABAA receptor expressed in Xenopus oocytes was enhanced in the presence of the three NSAIDs. The inhibition ratio profiles of the GABA responses for both drugs were analyzed with a newly developed toxicodynamic model. The inhibitory profiles for ENX in the presence of NSAIDs followed the order KTP (1.2 μM) > FRP (0.3 μM) > FLB (0.2 μM). These were 50- to 280-fold smaller than those observed in the absence of NSAIDs. The inhibition ratio (0.01 to 0.02) of the GABAA receptor in the presence of both drugs was well-fitted to the isobologram based on threshold concentrations of both drugs in brain tissue between mice with convulsions and those without convulsions, despite the presence of NSAIDs. In mice with convulsions, the inhibitory profiles of the threshold concentrations of both drugs in brain tissue of mice with convulsions and those without convulsions can be predicted quantitatively by using in vitro GABA response data and toxicodynamic model.

scholarly journals Sirtuin-2 Protects Neural Cells from Oxidative Stress and Is Elevated in Neurodegeneration

2017 ◽  
Vol 2017 ◽  
pp. 1-17 ◽  
Author(s):  
Preeti Singh ◽  
Peter S. Hanson ◽  
Christopher M. Morris
Keyword(s):  
Oxidative Stress ◽  
Cell Death ◽  
Brain Tissue ◽  
Postmortem Brain ◽  
Neural Cells ◽  
Compensatory Mechanism ◽  
Postmortem Brain Tissue ◽  
Lysine Deacetylases ◽  
Neuronal Stress

Sirtuins are highly conserved lysine deacetylases involved in ageing, energy production, and lifespan extension. The mammalian SIRT2 has been implicated in Parkinson’s disease (PD) where studies suggest SIRT2 promotes neurodegeneration. We therefore evaluated the effects of SIRT2 manipulation in toxin treated SH-SY5Y cells and determined the expression and activity of SIRT2 in postmortem brain tissue from patients with PD. SH-SY5Y viability in response to oxidative stress induced by diquat or rotenone was measured following SIRT2 overexpression or inhibition of deacetylase activity, along withα-synuclein aggregation. SIRT2 in human tissues was evaluated using Western blotting, immunohistochemistry, and fluorometric activity assays. In SH-SY5Y cells, elevated SIRT2 protected cells from rotenone or diquat induced cell death and enzymatic inhibition of SIRT2 enhanced cell death. SIRT2 protection was mediated, in part, through elevated SOD2 expression. SIRT2 reduced the formation ofα-synuclein aggregates but showed minimal colocalisation withα-synuclein. In postmortem PD brain tissue, SIRT2 activity was elevated compared to controls but also elevated in other neurodegenerative disorders. Results from both in vitro work and brain tissue suggest that SIRT2 is necessary for protection against oxidative stress and higher SIRT2 activity in PD brain may be a compensatory mechanism to combat neuronal stress.

scholarly journals EXPERIMENTS ON THE SURVIVAL OF THE FEBRILE HERPETIC AND ALLIED VIRUSES IN VITRO

1924 ◽  
Vol 39 (4) ◽  
pp. 533-542 ◽  
Author(s):  
James E. McCartney
Keyword(s):  
Brain Tissue ◽  
Secondary Infection ◽  
The Body ◽  
Herpes Viruses ◽  
Encephalitis Lethargica ◽  
Aerobic Conditions ◽  
Maximum Period ◽  
Suitable Technique ◽  
The Brain

These studies fail to confirm the statements previously made that microorganisms of the class of the globoid bodies of poliomyelitis may be cultivated in the Smith-Noguchi medium from the so called virus of encephalitis lethargica. They show equally that the herpes virus does not multiply in this medium. The experiments indicate, moreover, that the medium is unfavorable to the survival of the virus, while ordinary broth under aerobic conditions is more favorable for maintaining the activity of both the encephalitic and the herpes viruses. Probably no multiplication of either takes place in the latter medium but merely a survival, and for a maximum period of 6 days in the broth itself, and 12 days in the fragment of brain tissue immersed in the broth. Finally, it has been shown that with a suitable technique the viruses can be passed from the brain of one rabbit to that of another through a long series without contamination with cocci or other common bacterial forms. Hence we regard all reports of the finding of ordinary bacteria in the brain of cases of epidemic or lethargic encephalitis as instances of mixed or secondary infection arising during life, or examples of postmortem invasion of the body, or of faulty technique at the autopsy.

scholarly journals Identity and Origin of the ATPase activity associated with neuronal microtubules. I. The ATPase activity is associated with membrane vesicles.

1983 ◽  
Vol 96 (5) ◽  
pp. 1298-1305 ◽  
Author(s):  
D B Murphy ◽  
R R Hiebsch ◽  
K T Wallis
Keyword(s):  
Molecular Weight ◽  
Atpase Activity ◽  
High Molecular Weight ◽  
Brain Tissue ◽  
Membrane Vesicles ◽  
Microtubule Associated Proteins ◽  
In Vitro Assembly ◽  
Microtubule Protein ◽  
Associated Proteins

Microtubule protein purified from brain tissue by cycles of in vitro assembly-disassembly contains ATPase activity that has been postulated to be associated with microtubule-associated proteins (MAPs) and therefore significant for studies of microtubule-dependent motility. In this paper we demonstrate that greater than 90% of the ATPase activity is particulate in nature and may be derived from contaminating membrane vesicles. We also show that the MAPs (MAP-1, MAP-2, and tau factors) and other high molecular weight polypeptides do not contain significant amounts of ATPase activity. These findings do not support the concept of "brain dynein" or of MAPs with ATPase activity.

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