scholarly journals Combined Effects of Radiation and Methotrexate on the Cells of the Rat Subependymal Plate

1983 ◽  
Vol 76 (10) ◽  
pp. 848-852 ◽  
Author(s):  
A D Morris ◽  
J W Hopewell
Keyword(s):  
Cell Types ◽  
Intraventricular Injection ◽  
Nuclear Density ◽  
X Rays ◽  
Subependymal Plate ◽  
Severe Effect ◽  
Old Rats ◽  
Effects Of Radiation ◽  
Log Linear ◽  
The Brain

The brains of 20-week-old rats were locally irradiated with single doses of X-rays (400–1400 cGy). A similar group of animals received an intraventricular injection of methotrexate (MTX) prior to irradiation with single doses of X-rays (600–1400 cGy). Animals were killed six weeks after irradiation. A group of unirradiated age-matched animals acted as controls. In irradiated animals, the most severe effect on the subependymal plate (SEP) of the brain was denoted by the fall in the mitotic count (MC) and the number of small dark (SD) nucleated cells. SD nucleated cells are believed to represent the proliferative compartment of the subependymal layer. Other cell types in the SEP, believed to arise from the SD nucleated population, were affected to a lesser degree. After combination treatment with MTX, the decline in the MC and the SD nuclear density was more severe. The data for the dose-related decline in SD nuclear density and the MC fitted equally well on log-linear and linear plots. From the log-linear plots of the data it was concluded that MTX was radiation dose modifying (DMF 1.25–1.44). However, on the basis of the linear plots the effect of radiation and MTX was apparently additive. While no firm conclusions could be drawn regarding the mechanism of action of MTX on the radiation response of SEP cells, the possible mechanisms are discussed.

Endotoxin Alteration of the Mucopolysaccharide Blood Vessel Coating in Rats

1974 ◽  
Vol 32 ◽  
pp. 148-149
Author(s):  
D. E. Philpott ◽  
A. Takahashi
Keyword(s):  
Skeletal Muscle ◽  
Endothelial Cells ◽  
Salivary Gland ◽  
Carotid Artery ◽  
Basement Membrane ◽  
Coronary Vessels ◽  
Ruthenium Red ◽  
E Coli ◽  
Old Rats ◽  
The Brain

Two month, eight month and two year old rats were treated with 10 or 20 mg/kg of E. Coli endotoxin I. P. The eight month old rats proved most resistant to the endotoxin. During fixation the aorta, carotid artery, basil arartery of the brain, coronary vessels of the heart, inner surfaces of the heart chambers, heart and skeletal muscle, lung, liver, kidney, spleen, brain, retina, trachae, intestine, salivary gland, adrenal gland and gingiva were treated with ruthenium red or alcian blue to preserve the mucopolysaccharide (MPS) coating. Five, 8 and 24 hrs of endotoxin treatment produced increasingly marked capillary damage, disappearance of the MPS coating, edema, destruction of endothelial cells and damage to the basement membrane in the liver, kidney and lung.

A Review of Various Machine Learning Techniques for Brain Tumor Detection from MRI Images

2020 ◽  
Vol 16 (8) ◽  
pp. 937-945
Author(s):  
Aaishwarya Sanjay Bajaj ◽  
Usha Chouhan
Keyword(s):  
Machine Learning ◽  
Brain Tumor ◽  
Ct Scan ◽  
Imaging Techniques ◽  
Critical Evaluation ◽  
Tumor Detection ◽  
Machine Learning Techniques ◽  
X Rays ◽  
Detection Techniques ◽  
The Brain

Background: This paper endeavors to identify an expedient approach for the detection of the brain tumor in MRI images. The detection of tumor is based on i) review of the machine learning approach for the identification of brain tumor and ii) review of a suitable approach for brain tumor detection. Discussion: This review focuses on different imaging techniques such as X-rays, PET, CT- Scan, and MRI. This survey identifies a different approach with better accuracy for tumor detection. This further includes the image processing method. In most applications, machine learning shows better performance than manual segmentation of the brain tumors from MRI images as it is a difficult and time-consuming task. For fast and better computational results, radiology used a different approach with MRI, CT-scan, X-ray, and PET. Furthermore, summarizing the literature, this paper also provides a critical evaluation of the surveyed literature which reveals new facets of research. Conclusion: The problem faced by the researchers during brain tumor detection techniques and machine learning applications for clinical settings have also been discussed.

scholarly journals Neural Stem Cells: What Happens When They Go Viral?

Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1468
Author(s):  
Yashika S. Kamte ◽  
Manisha N. Chandwani ◽  
Alexa C. Michaels ◽  
Lauren A. O’Donnell
Keyword(s):  
Stem Cells ◽  
Neural Stem Cells ◽  
Viral Infections ◽  
Wide Spectrum ◽  
Cell Types ◽  
Developmental Abnormalities ◽  
Multipotent Progenitor Cells ◽  
The Central Nervous System ◽  
Simplex Virus ◽  
The Brain

Viruses that infect the central nervous system (CNS) are associated with developmental abnormalities as well as neuropsychiatric and degenerative conditions. Many of these viruses such as Zika virus (ZIKV), cytomegalovirus (CMV), and herpes simplex virus (HSV) demonstrate tropism for neural stem cells (NSCs). NSCs are the multipotent progenitor cells of the brain that have the ability to form neurons, astrocytes, and oligodendrocytes. Viral infections often alter the function of NSCs, with profound impacts on the growth and repair of the brain. There are a wide spectrum of effects on NSCs, which differ by the type of virus, the model system, the cell types studied, and the age of the host. Thus, it is a challenge to predict and define the consequences of interactions between viruses and NSCs. The purpose of this review is to dissect the mechanisms by which viruses can affect survival, proliferation, and differentiation of NSCs. This review also sheds light on the contribution of key antiviral cytokines in the impairment of NSC activity during a viral infection, revealing a complex interplay between NSCs, viruses, and the immune system.

scholarly journals MiR-7 in Cancer Development

Biomedicines ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 325
Author(s):  
Petra Korać ◽  
Mariastefania Antica ◽  
Maja Matulić
Keyword(s):  
Cell Fate ◽  
Dominant Role ◽  
Tumor Development ◽  
Mrna Translation ◽  
Cell Types ◽  
Fine Tuning ◽  
Non Coding Rna ◽  
Tumor Types ◽  
Different Cell Types ◽  
The Brain

MicroRNAs (miRNAs) are short non-coding RNA involved in the regulation of specific mRNA translation. They participate in cellular signaling circuits and can act as oncogenes in tumor development, so-called oncomirs, as well as tumor suppressors. miR-7 is an ancient miRNA involved in the fine-tuning of several signaling pathways, acting mainly as tumor suppressor. Through downregulation of PI3K and MAPK pathways, its dominant role is the suppression of proliferation and survival, stimulation of apoptosis and inhibition of migration. Besides these functions, it has numerous additional roles in the differentiation process of different cell types, protection from stress and chromatin remodulation. One of the most investigated tissues is the brain, where its downregulation is linked with glioblastoma cell proliferation. Its deregulation is found also in other tumor types, such as in liver, lung and pancreas. In some types of lung and oral carcinoma, it can act as oncomir. miR-7 roles in cell fate determination and maintenance of cell homeostasis are still to be discovered, as well as the possibilities of its use as a specific biotherapeutic.

scholarly journals The Microbiota–Gut–Brain Axis and Alzheimer Disease. From Dysbiosis to Neurodegeneration: Focus on the Central Nervous System Glial Cells

2021 ◽  
Vol 10 (11) ◽  
pp. 2358
Author(s):  
Maria Grazia Giovannini ◽  
Daniele Lana ◽  
Chiara Traini ◽  
Maria Giuliana Vannucchi
Keyword(s):  
Alzheimer Disease ◽  
Glial Cells ◽  
Cell Types ◽  
The Past ◽  
The Central Nervous System ◽  
Diseased State ◽  
The Brain ◽  
Alzheimer Disease Pathogenesis ◽  
Brain Homeostasis

The microbiota–gut system can be thought of as a single unit that interacts with the brain via the “two-way” microbiota–gut–brain axis. Through this axis, a constant interplay mediated by the several products originating from the microbiota guarantees the physiological development and shaping of the gut and the brain. In the present review will be described the modalities through which the microbiota and gut control each other, and the main microbiota products conditioning both local and brain homeostasis. Much evidence has accumulated over the past decade in favor of a significant association between dysbiosis, neuroinflammation and neurodegeneration. Presently, the pathogenetic mechanisms triggered by molecules produced by the altered microbiota, also responsible for the onset and evolution of Alzheimer disease, will be described. Our attention will be focused on the role of astrocytes and microglia. Numerous studies have progressively demonstrated how these glial cells are important to ensure an adequate environment for neuronal activity in healthy conditions. Furthermore, it is becoming evident how both cell types can mediate the onset of neuroinflammation and lead to neurodegeneration when subjected to pathological stimuli. Based on this information, the role of the major microbiota products in shifting the activation profiles of astrocytes and microglia from a healthy to a diseased state will be discussed, focusing on Alzheimer disease pathogenesis.

scholarly journals Microglia in Neurodegenerative Events—An Initiator or a Significant Other?

2021 ◽  
Vol 22 (11) ◽  
pp. 5818
Author(s):  
Gaylia Jean Harry
Keyword(s):  
Neurovascular Unit ◽  
Cell Types ◽  
In Vitro Assays ◽  
Significant Other ◽  
Neurodegenerative Process ◽  
Target Sites ◽  
Systemic Factors ◽  
Injury And Repair ◽  
The Brain

A change in microglia structure, signaling, or function is commonly associated with neurodegeneration. This is evident in the patient population, animal models, and targeted in vitro assays. While there is a clear association, it is not evident that microglia serve as an initiator of neurodegeneration. Rather, the dynamics imply a close interaction between the various cell types and structures in the brain that orchestrate the injury and repair responses. Communication between microglia and neurons contributes to the physiological phenotype of microglia maintaining cells in a surveillance state and allows the cells to respond to events occurring in their environment. Interactions between microglia and astrocytes is not as well characterized, nor are interactions with other members of the neurovascular unit; however, given the influence of systemic factors on neuroinflammation and disease progression, such interactions likely represent significant contributes to any neurodegenerative process. In addition, they offer multiple target sites/processes by which environmental exposures could contribute to neurodegenerative disease. Thus, microglia at least play a role as a significant other with an equal partnership; however, claiming a role as an initiator of neurodegeneration remains somewhat controversial.

Thiamine transport in the central nervous system

1976 ◽  
Vol 230 (4) ◽  
pp. 1101-1107 ◽  
Author(s):  
R Spector
Keyword(s):  
Choroid Plexus ◽  
Intraventricular Injection ◽  
Simple Diffusion ◽  
Thiamine Transport ◽  
Choroid Plexuses ◽  
The Central Nervous System ◽  
The Brain ◽  
Thiamine Phosphates

Total thiamine (free thiamine and thiamine phosphates) transport into the cerebrospinal fluid (CSF), brain, and choroid plexus and out of the CSF was measured in rabbits. In vivo, total thiamine transport into CSF, choroid plexus, and brain was saturable. At the normal plasma total thiamine concentration, less than 5% of total thiamine entry into CSF, choroid plexus, and brain was by simple diffusion. The relative turnovers of total thiamine in choroid plexus, whole brain, and CSF were 5, 2, and 14% per h, respectively, when measured by the penetration of 35S-labeled thiamine injected into blood. From the CSF, clearance of [35S]thiamine relative to mannitol was not saturable after the intraventricular injection of various concentrations of thiamine. However, a portion of the [35S]thiamine cleared from the CSF entered brain by a saturable mechanism. In vitro, choroid plexuses, isolated from rabbits and incubated in artificial CSF, accumulated [35S]thiamine against a concentration gradient by an active saturable process that did not depend on pyrophosphorylation of the [35S]thiamine. The [35S]thiamine accumulated within the choroid plexus in vitro was readily released. These results were interpreted as showing that the entry of total thiamine into the brain and CSF from blood is regulated by a saturable transport system, and that the locus of this system may be, in part, in the choroid plexus.

Sign in / Sign up

Export Citation Format

Share Document