scholarly journals Streptococcal Meningitis Reveals the Presence of Residual Streptococci and Down-Regulated Aquaporin 4 in the Brain

Author(s):  
Tatsuya Nakayama

Abstract The pathology of streptococcal meningitis is poorly understood, even though streptococcal infection induces meningitis. The aim of this study was to clarify the relationship between streptococcal meningitis and aquaporin 4 (AQP4) in the mouse brain. After Streptococcus suis infection, the streptococcal number was calculated, and AQP4 mRNA expression in the brain was quantified at 2 and 7 days after infection. At 7 days post-infection, mice with neurological symptoms showed significantly higher S. suis levels in the brain than mice without neurological symptoms. AQP4 expression was significantly decreased in mice with neurological symptoms than in mice without neurological symptoms. Image analysis demonstrated that S. suis progressed to invade the white matter. Pathological analysis revealed that infected mouse brains had higher inflammation and neurological damage scores than uninfected mouse brains. Therefore, mice with neurological symptoms caused by streptococcal meningitis had high S. suis levels in the brain and reduced AQP4 expression.

2021 ◽  
Vol 36 (4) ◽  
pp. 285-296
Author(s):  
Adriana Wawer ◽  
Agnieszka Piechal

Objective. Some viral infections can have a harmful effect on the functioning of the nervous system and can even cause serious neurological damage. This work aims to review the results of studies published so far concerning neurological complications in people infected with coronaviruses, especially SARS-CoV-2, and possible mechanisms responsible for nervous system damage. Literature review. Recently, there have been reports that coronaviruses, including SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2), cause acute respiratory disease, exhibit neurotropic properties and can also cause neurological symptoms. There are studies published showing that these viruses may penetrate to the brain and cerebrospinal fluid. Conclusions. Coronaviruses are still poorly understood, so it seems important to study the potential impact of SARS-CoV-2 infections on the nervous system. It seems appropriate that patients infected with SARS-CoV-2 should be early evaluated for neurological symptoms, including headache and impaired consciousness.


Cells ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 2187
Author(s):  
Sven Olaf Rohr ◽  
Theresa Greiner ◽  
Sarah Joost ◽  
Sandra Amor ◽  
Paul van der Valk ◽  
...  

The water channel protein aquaporin-4 (AQP4) is required for a normal rate of water exchange across the blood–brain interface. Following the discovery that AQP4 is a possible autoantigen in neuromyelitis optica, the function of AQP4 in health and disease has become a research focus. While several studies have addressed the expression and function of AQP4 during inflammatory demyelination, relatively little is known about its expression during non-autoimmune-mediated myelin damage. In this study, we used the toxin-induced demyelination model cuprizone as well as a combination of metabolic and autoimmune myelin injury (i.e., Cup/EAE) to investigate AQP4 pathology. We show that during toxin-induced demyelination, diffuse AQP4 expression increases, while polarized AQP4 expression at the astrocyte endfeet decreases. The diffuse increased expression of AQP4 was verified in chronic-active multiple sclerosis lesions. Around inflammatory brain lesions, AQP4 expression dramatically decreased, especially at sites where peripheral immune cells penetrate the brain parenchyma. Humoral immune responses appear not to be involved in this process since no anti-AQP4 antibodies were detected in the serum of the experimental mice. We provide strong evidence that the diffuse increase in anti-AQP4 staining intensity is due to a metabolic injury to the brain, whereas the focal, perivascular loss of anti-AQP4 immunoreactivity is mediated by peripheral immune cells.


2021 ◽  
Vol 22 (18) ◽  
pp. 9745
Author(s):  
José Luis Trillo-Contreras ◽  
Juan José Toledo-Aral ◽  
Javier Villadiego ◽  
Miriam Echevarría

Aquaporin-4 (AQP4) is the principal water channel in the brain being expressed in astrocytes and ependymal cells. AQP4 plays an important role in cerebrospinal fluid (CSF) homeostasis, and alterations in its expression have been associated with hydrocephalus. AQP4 contributes to the development of hydrocephalus by hypoxia in aged mice, reproducing such principal characteristics of the disease. Here, we explore whether these alterations associated with the hydrocephalic state are permanent or can be reverted by reexposure to normoxia. Alterations such as ventriculomegaly, elevated intracranial pressure, and cognitive deficits were reversed, whereas deficits in CSF outflow and ventricular distensibility were not recovered, remaining impaired even one month after reestablishment of normoxia. Interestingly, in AQP4−/− mice, the impairment in CSF drainage and ventricular distensibility was completely reverted by re-normoxia, indicating that AQP4 has a structural role in the chronification of those alterations. Finally, we show that aged mice subjected to two hypoxic episodes experience permanent ventriculomegaly. These data reveal that repetitive hypoxic events in aged cerebral tissue promote the permanent alterations involved in hydrocephalic pathophysiology, which are dependent on AQP4 expression.


2010 ◽  
Vol 2010 (1) ◽  
pp. 5-22
Author(s):  
Ralf Becker

The article examines the relationship between freedom, guilt and responsibility in Dostojewski’s and Sartre’s works. Both attribute a great measure of personal freedom to man. Therefore, they do not tolerate excuses. Whoever is free, carries responsibility and gets caught up in guilt. Dostojewski’s focus is mainly on guilt, Sartre’s is on responsibility. They share the conviction that we can delegate responsibility for our actions or our way of living neither to a whole, of which we are a part, like society (the ,milieu'), nor to a part, for which we are the whole, like the ,brain' or the ,genes'. In that sense, Dostojewski’s and Sartre’s attempts at an ethic of responsibility also offer convincing arguments against determinism.


Author(s):  
M.P. Sutunkova ◽  
B.A. Katsnelson ◽  
L.I. Privalova ◽  
S.N. Solovjeva ◽  
V.B. Gurvich ◽  
...  

We conducted a comparative assessment of the nickel oxide nanoparticles toxicity (NiO) of two sizes (11 and 25 nm) according to a number of indicators of the body state after repeated intraperitoneal injections of these particles suspensions. At equal mass doses, NiO nanoparticles have been found to cause various manifestations of systemic subchronic toxicity with a particularly pronounced effect on liver, kidney function, the body’s antioxidant system, lipid metabolism, white and red blood, redox metabolism, spleen damage, and some disorders of nervous activity allegedly related to the possibility of nickel penetration into the brain from the blood. The relationship between the diameter and toxicity of particles is ambiguous, which may be due to differences in toxicokinetics, which is controlled by both physiological mechanisms and direct penetration of nanoparticles through biological barriers and, finally, unequal solubility.


2020 ◽  
Vol 21 (9) ◽  
pp. 649-660
Author(s):  
Subashini Raman ◽  
Syed Mahmood ◽  
Ayah R. Hilles ◽  
Md Noushad Javed ◽  
Motia Azmana ◽  
...  

Background: Blood-brain barrier (BBB) plays a most hindering role in drug delivery to the brain. Recent research comes out with the nanoparticles approach, is continuously working towards improving the delivery to the brain. Currently, polymeric nanoparticle is extensively involved in many therapies for spatial and temporal targeted areas delivery. Methods: We did a non-systematic review, and the literature was searched in Google, Science Direct and PubMed. An overview is provided for the formulation of polymeric nanoparticles using different methods, effect of surface modification on the nanoparticle properties with types of polymeric nanoparticles and preparation methods. An account of different nanomedicine employed with therapeutic agent to cross the BBB alone with biodistribution of the drugs. Results: We found that various types of polymeric nanoparticle systems are available and they prosper in delivering the therapeutic amount of the drug to the targeted area. The effect of physicochemical properties on nanoformulation includes change in their size, shape, elasticity, surface charge and hydrophobicity. Surface modification of polymers or nanocarriers is also vital in the formulation of nanoparticles to enhance targeting efficiency to the brain. Conclusion: More standardized methods for the preparation of nanoparticles and to assess the relationship of surface modification on drug delivery. While the preparation and its output like drug loading, particle size, and charge, permeation is always conflicted, so it requires more attention for the acceptance of nanoparticles for brain delivery.


2021 ◽  
Vol 190 ◽  
pp. 553-559
Author(s):  
Irina K. Malashenkova ◽  
Vadim L. Ushakov ◽  
Sergey A. Krynskiy ◽  
Daniil P. Ogurtsov ◽  
Nikita A. Khailov ◽  
...  

Biomedicines ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 340
Author(s):  
Lehel Balogh ◽  
Masaru Tanaka ◽  
Nóra Török ◽  
László Vécsei ◽  
Shigeru Taguchi

Psychotherapy is a comprehensive biological treatment modifying complex underlying cognitive, emotional, behavioral, and regulatory responses in the brain, leading patients with mental illness to a new interpretation of the sense of self and others. Psychotherapy is an art of science integrated with psychology and/or philosophy. Neurological sciences study the neurological basis of cognition, memory, and behavior as well as the impact of neurological damage and disease on these functions, and their treatment. Both psychotherapy and neurological sciences deal with the brain; nevertheless, they continue to stay polarized. Existential phenomenological psychotherapy (EPP) has been in the forefront of meaning-centered counseling for almost a century. The phenomenological approach in psychotherapy originated in the works of Martin Heidegger, Ludwig Binswanger, Medard Boss, and Viktor Frankl, and it has been committed to accounting for the existential possibilities and limitations of one’s life. EPP provides philosophically rich interpretations and empowers counseling techniques to assist mentally suffering individuals by finding meaning and purpose to life. The approach has proven to be effective in treating mood and anxiety disorders. This narrative review article demonstrates the development of EPP, the therapeutic methodology, evidence-based accounts of its curative techniques, current understanding of mood and anxiety disorders in neurological sciences, and a possible converging path to translate and integrate meaning-centered psychotherapy and neuroscience, concluding that the EPP may potentially play a synergistic role with the currently prevailing medication-based approaches for the treatment of mood and anxiety disorders.


Neurology ◽  
2018 ◽  
Vol 91 (23 Supplement 1) ◽  
pp. S17.1-S17
Author(s):  
Haruo Nakayama ◽  
Yu Hiramoto ◽  
Yuriko Numata ◽  
Satoshi Fujita ◽  
Nozomi Hirai ◽  
...  

ObjectiveTo evaluate the relationship between functional anisotropy (FA) and neuropsychological evaluation in concussion.MethodsDiffusion tensor MRI included FA of the Brain and neuropsychological evaluation were conducted on 10 patients with concussion who were diagnosed from April 2017 to March 2018. FA was extracted from 2 regions of interest in Corpus callosum (CC) and corticospinal tract (CT). Detailed neuropsychological testing with an emphasis on Working memory (WM) and Processing speed (PS) was also conducted. The FA value in that 2 regions were compared between the 2 groups of 5 patients (group F) who failed either in WM or PS and 5 cases (group NF) who did not admit it.ResultsMean FA values in CC and CT in the Group F were 0.70 and 0.52. Mean FA values in CC and CT in the Group NF were 0.48 and 0.55.ConclusionsOur result suggests that the FA value of CC did not explain the significant fluctuation of the neuropsychological function. However, FA value in CT were shown to explain the fluctuation of WM and PS.


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