A HISTOCHEMICAL AND BIOCHEMICAL STUDY OF THE POLYSACCHARIDIC SUBSTANCES OF THE DEVELOPING NERVOUS SYSTEM OF THE RAT IN RELATION WITH THE APPEARANCE OF CHOLINESTERASE ACTIVITY

1958 ◽  
Vol 36 (1) ◽  
pp. 275-288 ◽  
Author(s):  
Marc Crevier
Keyword(s):  
Nervous System ◽  
Acid Hydrolysis ◽  
Biochemical Study ◽  
Chemical Fractionation ◽  
High Concentration ◽  
Brain Substance ◽  
Pas Reaction ◽  
Irregular Action ◽  
Developing Nervous System

The PAS reaction and the cholinesterase reaction run parallel in the lower centers of the developing nervous system in the rat. Also, the two reactions appear progressively between the 10th and 15th day as the result of a chemical maturation of the neurons. Extraction of sections with methanol–chloroform does not alter the PAS reaction while acetylation inhibits it reversibly. These two facts suggest that 1,2-glycol groups are detected. Inhibition by hyaluronidase increases this evidence, despite the fact that diastase has a slight and irregular action. To elucidate the nature of the PAS reaction further, chemical fractionation of the brain substance has been attempted. (A) A fraction soluble in methanol–chloroform is metachromatic and PAS-positive in vitro. (B) A fraction soluble in a potassium chloride – potassium carbonate mixture is non-dialyzable, non-metachromatic, but PAS-positive. After acid hydrolysis it yields glucose but no hexosamine. (C) A fraction extracted from the residue by sodium hydroxide is non-dialyzable, non-metachromatic, but also PAS-positive. By chromatography and electrophoresis it is found to contain a non-sulphated mucoprotein yielding hexosamine in a high concentration following acid hydrolysis. The physiological significance of this mucoprotein is discussed.

A HISTOCHEMICAL AND BIOCHEMICAL STUDY OF THE POLYSACCHARIDIC SUBSTANCES OF THE DEVELOPING NERVOUS SYSTEM OF THE RAT IN RELATION WITH THE APPEARANCE OF CHOLINESTERASE ACTIVITY

1958 ◽  
Vol 36 (3) ◽  
pp. 275-288 ◽  
Author(s):  
Marc Crevier
Keyword(s):  
Nervous System ◽  
Acid Hydrolysis ◽  
Biochemical Study ◽  
Chemical Fractionation ◽  
High Concentration ◽  
Brain Substance ◽  
Pas Reaction ◽  
Irregular Action ◽  
Developing Nervous System

The PAS reaction and the cholinesterase reaction run parallel in the lower centers of the developing nervous system in the rat. Also, the two reactions appear progressively between the 10th and 15th day as the result of a chemical maturation of the neurons. Extraction of sections with methanol–chloroform does not alter the PAS reaction while acetylation inhibits it reversibly. These two facts suggest that 1,2-glycol groups are detected. Inhibition by hyaluronidase increases this evidence, despite the fact that diastase has a slight and irregular action. To elucidate the nature of the PAS reaction further, chemical fractionation of the brain substance has been attempted. (A) A fraction soluble in methanol–chloroform is metachromatic and PAS-positive in vitro. (B) A fraction soluble in a potassium chloride – potassium carbonate mixture is non-dialyzable, non-metachromatic, but PAS-positive. After acid hydrolysis it yields glucose but no hexosamine. (C) A fraction extracted from the residue by sodium hydroxide is non-dialyzable, non-metachromatic, but also PAS-positive. By chromatography and electrophoresis it is found to contain a non-sulphated mucoprotein yielding hexosamine in a high concentration following acid hydrolysis. The physiological significance of this mucoprotein is discussed.

Developmental programmes of growth and survival in early sensory neurons

1991 ◽  
Vol 331 (1261) ◽  
pp. 259-262
Keyword(s):  
Nervous System ◽  
Sensory Neurons ◽  
Neurotrophic Factor ◽  
Target Distance ◽  
Trophic Factor ◽  
Growth And Survival ◽  
Target Field ◽  
Developing Nervous System

In the developing vertebrate nervous system the survival of neurons becomes dependent on the supply of a neurotrophic factor from their targets when their axons reach these targets. To determine how the onset of neurotrophic factor dependency is coordinated with the arrival of axons in the target field, we have studied the growth and survival of four populations of cranial sensory neurons whose axons have markedly different distances to grow to reach their targets. Axonal growth rate both in vivo and in vitro is related to target distance; neurons with more distant targets grow faster. The onset trophic factor dependency in culture is also related to target distance; neurons with more distant targets survive longer before becoming trophic factor dependent. These data suggest that programmes of growth and survival in early neurons play an important role in coordinating the timing of trophic interactions in the developing nervous system.

scholarly journals A Critical Temporal Requirement for the Retinoblastoma Protein Family During Neuronal Determination

1998 ◽  
Vol 140 (6) ◽  
pp. 1497-1509 ◽  
Author(s):  
Ruth S. Slack ◽  
Hiba El-Bizri ◽  
Josée Wong ◽  
Daniel J. Belliveau ◽  
Freda D. Miller
Keyword(s):  
Cell Cycle ◽  
Nervous System ◽  
Cortical Neurons ◽  
Adenovirus E1a ◽  
Neuronal Gene ◽  
Developing Neocortex ◽  
Postmitotic Neurons ◽  
Developing Nervous System

In this report, we have examined the requirement for the retinoblastoma (Rb) gene family in neuronal determination with a focus on the developing neocortex. To determine whether pRb is required for neuronal determination in vivo, we crossed the Rb−/− mice with transgenic mice expressing β-galactosidase from the early, panneuronal Tα1 α-tubulin promoter (Tα1:nlacZ). In E12.5 Rb−/− embryos, the Tα1:nlacZ transgene was robustly expressed throughout the developing nervous system. However, by E14.5, there were perturbations in Tα1:nlacZ expression throughout the nervous system, including deficits in the forebrain and retina. To more precisely define the temporal requirement for pRb in neuronal determination, we functionally ablated the pRb family in wild-type cortical progenitor cells that undergo the transition to postmitotic neurons in vitro by expression of a mutant adenovirus E1A protein. These studies revealed that induction of Tα1:nlacZ did not require proteins of the pRb family. However, in their absence, determined, Tα1:nlacZ-positive cortical neurons underwent apoptosis, presumably as a consequence of “mixed signals” deriving from their inability to undergo terminal mitosis. In contrast, when the pRb family was ablated in postmitotic cortical neurons, there was no effect on neuronal survival, nor did it cause the postmitotic neurons to reenter the cell cycle. Together, these studies define a critical temporal window of requirement for the pRb family; these proteins are not required for induction of neuronal gene expression or for the maintenance of postmitotic neurons, but are essential for determined neurons to exit the cell cycle and survive.

Oligodendrocyte precursor (O-2A progenitor cell) migration; a model system for the study of cell migration in the developing central nervous system

Development ◽  
1993 ◽  
Vol 119 (Supplement) ◽  
pp. 219-225 ◽  
Author(s):  
B. W. Kiernan ◽  
Charles ffrench-Constant
Keyword(s):  
Nervous System ◽  
Cell Migration ◽  
Progenitor Cell ◽  
Molecular Mechanisms ◽  
Cultured Cells ◽  
Large Numbers ◽  
Multicellular Organisms ◽  
Developing Nervous System

Cell migration plays an important role in the development of complex multicellular organisms. The molecular mechanisms that regulate this migration arc therefore of great interest. Unfortunately, however, analysis of cell migration in vertebrates is hampered by the inaccessability of the cells and the difficulty of manipulating their environment within the embryo. This review focusses on one particular migratory cell population, the oligodendrocyte p1ecursor cell or O-2A progenitor cell, that gives rise to the myelin-forming oligodendrocytes within the CNS. These cells mi grate extensively during normal development. They can be purified and grown in large numbers in cell culture, so allowing the use of reductionist approaches using cell and molecular biology techniques. Moreover, cultured cells will migrate within the CNS following transplantation. As a result, the migration of these cells in vivo can be analysed following manipulation in vitro. Taken together, we believe that the different properties of these cells makes them excellent candidates for studies addressing the control of cell migration in the developing nervous system.

scholarly journals Identification of MoKA, a Novel F-Box Protein That Modulates Krüppel-Like Transcription Factor 7 Activity

2004 ◽  
Vol 24 (3) ◽  
pp. 1058-1069 ◽  
Author(s):  
Silvia Smaldone ◽  
Friedrich Laub ◽  
Cindy Else ◽  
Cecilia Dragomir ◽  
Francesco Ramirez
Keyword(s):  
Cell Cycle ◽  
Nervous System ◽  
Transcription Factor ◽  
Mammalian Cells ◽  
Cell Cycle Progression ◽  
Direct Interaction ◽  
Proximal Promoter ◽  
F Box Protein ◽  
Developing Nervous System

ABSTRACT KLF7, a member of the Krüppel-like transcription factor family, is believed to regulate neurogenesis and cell cycle progression. Here, a yeast two-hybrid screen for KLF7 cofactors in the developing nervous system identified a novel 140-kDa protein named MoKA, for modulator of KLF7 activity. Interaction between MoKA and KLF7 was confirmed by the in vitro glutathione S-transferase pull-down assay and by coimmunoprecipitation of the proteins overexpressed in mammalian cells. Functional assays documented that MoKA is a KLF7 coactivator, and in situ hybridizations identified the developing nervous system and the adult testes as two sites of MoKA and Klf7 coexpression. Chromatin immunoprecipitation experiments demonstrated KLF7 binding to the p21WAF1/Cip1 gene while transient transfection assays documented KLF7 stimulation of the p21WAF1/Cip1 proximal promoter. Additional tests revealed that distinct structural motifs of MoKA direct interaction with KLF7 and shuttling between the nucleus and cytoplasm of asynchronously cycling cells. Altogether, our results strongly suggest that MoKA and KLF7 interact functionally to regulate gene expression during cell differentiation and identify the cell cycle regulator p21WAF1/Cip1 as one of the targeted genes.

scholarly journals Chicken Acidic Leucine-rich EGF-like Domain Containing Brain Protein (CALEB), a Neural Member of the EGF Family of Differentiation Factors, Is Implicated in Neurite Formation

1997 ◽  
Vol 136 (4) ◽  
pp. 895-906 ◽  
Author(s):  
Stefan Schumacher ◽  
Hansjürgen Volkmer ◽  
Fritz Buck ◽  
Albrecht Otto ◽  
Attila Tárnok ◽  
...  
Keyword(s):  
Nervous System ◽  
Brain Protein ◽  
Binding Assays ◽  
Multidomain Protein ◽  
Differentiation Factors ◽  
Neurite Formation ◽  
Embryonic Nervous System ◽  
Egf Family ◽  
Developing Nervous System

Chicken acidic leucine-rich EGF-like domain containing brain protein (CALEB) was identified by combining binding assays with immunological screens in the chicken nervous system as a novel member of the EGF family of differentiation factors. cDNA cloning indicates that CALEB is a multidomain protein that consists of an NH2-terminal glycosylation region, a leucine-proline–rich segment, an acidic box, a single EGF-like domain, a transmembrane, and a short cytoplasmic stretch. In the developing nervous system, CALEB is associated with glial and neuronal surfaces. CALEB is composed of a 140/130-kD doublet, an 80-kD band, and a chondroitinsulfate-containing 200-kD component. The latter two components are expressed in the embryonic nervous system and are downregulated in the adult nervous system. CALEB binds to the extracellular matrix glycoproteins tenascin-C and -R. In vitro antibody perturbation experiments reveal a participation of CALEB in neurite formation in a permissive environment.

The Teratogenic effects of salicylic acid on the developing nervous system in rats in vitro

Teratology ◽  
1993 ◽  
Vol 48 (2) ◽  
pp. 105-114 ◽  
Author(s):  
Marion A. Joschko ◽  
Ivor E. Dreosti ◽  
Ram S. Tulsi
Keyword(s):  
Nervous System ◽  
Salicylic Acid ◽  
Teratogenic Effects ◽  
Developing Nervous System

Principles of masking organoleptic properties of bitter tasting medicines

2020 ◽  
pp. 25-32
Author(s):  
Mariya Anurova ◽  
Elena Bakhrushina ◽  
Anna Moiseyeva ◽  
Ivan Krasnyuk
Keyword(s):  
Nervous System ◽  
Patient Compliance ◽  
Dosage Form ◽  
Bitter Taste ◽  
Drug Uptake ◽  
Taste Masking ◽  
Pure Substance ◽  
High Concentration ◽  
Organoleptic Properties ◽  
Gel Composition

Patient compliance of drug therapy is the key factor in achieving the pharmaceutical effect. Taste masking is particularly important in pediatrics and geriatrics because the unpleasant taste negatively affects drug uptake. Patient compliance can be improved through balanced organoleptic properties of medicines. It is particularly important to choose optimal correction method for medicines with high concentration of the active substance. Hopantenic acid has been chosen as a model drug due to its bitter taste. Taste masking technologies for creating a new dosage form with optimal organoleptic properties are proposed in the article. The objective is to achieve an experimentally justified choice of technological approach to masking bitter taste of a substance and to create a new dosage form on its basis. Materials and methods. Alternative technologies were considered to solve this problem: granulation, creation of complexes with ion-exchange resins, introduction of a gel composition and taste-masking using sweeteners. Organoleptic properties in dry compositions (pure substance of hopantenic acid, granulate and resinate based on it), and also after preparation of liquid dosage forms and incorporation them into gel, were evaluated by A. I. Tentsova method. Choice of sweetener and its concentration to achieve an optimally balanced taste took place at the final stage. Hopantenic acid was chosen as a model substance. Hopantenic acid is a nootropic drug stimulating cognitive functions, nervous system, enhancing intellectual functioning, decreasing nervous system activity, with anticonvulsant action. The main therapeutic indications are mental retardation, dementia, epilepsy. Results and discussion. The study has shown that optimal technology for masking unpleasant taste of hopantenic acid is its introduction into a gel composition, and a promising dosage form is an oral gel. Compri-Zucker G sweetener (Südzucker АG, Germany) in concentration of 5 % has been chosen to create pleasant taste due to its highest taste rating. Conclusion. It has been determined as a result of the study that oral gel with active drug concentration of 5 % and sweetener concentration of 5 % has optimal organoleptic properties. Thus, this combination of active and additional substances can be considered the most perspective for developing a new dosage form of a medicine.

Neural Stem Cells to Glial Cells an Important Factor for Brain Injury

2020 ◽  
Author(s):  
Prithiv K R Kumar
Keyword(s):  
Stem Cells ◽  
Central Nervous System ◽  
Nervous System ◽  
Neural Stem Cells ◽  
Glial Cells ◽  
Brain Injuries ◽  
The Body ◽  
The Central Nervous System ◽  
Near Future

Stem cells have the capacity to differentiate into any type of cell or organ. Stems cell originate from any part of the body, including the brain. Brain cells or rather neural stem cells have the capacitive advantage of differentiating into the central nervous system leading to the formation of neurons and glial cells. Neural stem cells should have a source by editing DNA, or by mixings chemical enzymes of iPSCs. By this method, a limitless number of neuron stem cells can be obtained. Increase in supply of NSCs help in repairing glial cells which in-turn heal the central nervous system. Generally, brain injuries cause motor and sensory deficits leading to stroke. With all trials from novel therapeutic methods to enhanced rehabilitation time, the economy and quality of life is suppressed. Only PSCs have proven effective for grafting cells into NSCs. Neurons derived from stem cells is the only challenge that limits in-vitro usage in the near future.

The Effects of Shock Vancomycin Concentrations on the Formation of Heteroresistance in Staphylococcus aureus

2020 ◽  
Vol 65 (9-10) ◽  
pp. 3-7
Author(s):  
V. V. Gostev ◽  
Yu. V. Sopova ◽  
O. S. Kalinogorskaya ◽  
M. E. Velizhanina ◽  
I. V. Lazareva ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
In Vitro Selection ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
High Concentration ◽  
Short Term ◽  
High Concentrations ◽  
Selection Of ◽  
Selection Of Resistance ◽  
Test Cultures

Glycopeptides are the basis of the treatment of infections caused by MRSA (Methicillin-Resistant Staphylococcus aureus). Previously, it was demonstrated that antibiotic tolerant phenotypes are formed during selection of resistance under the influence of high concentrations of antibiotics. The present study uses a similar in vitro selection model with vancomycin. Clinical isolates of MRSA belonging to genetic lines ST8 and ST239, as well as the MSSA (ATCC29213) strain, were included in the experiment. Test isolates were incubated for five hours in a medium with a high concentration of vancomycin (50 μg/ml). Test cultures were grown on the medium without antibiotic for 18 hours after each exposure. A total of ten exposure cycles were performed. Vancomycin was characterized by bacteriostatic action; the proportion of surviving cells after exposure was 70–100%. After selection, there was a slight increase in the MIC to vancomycin (MIC 2 μg/ml), teicoplanin (MIC 1.5–3 μg/ml) and daptomycin (MIC 0.25–2 μg/ml). According to the results of PAP analysis, all strains showed an increase in the area under curve depending on the concentration of vancomycin after selection, while a heteroresistant phenotype (with PAP/AUC 0.9) was detected in three isolates. All isolates showed walK mutations (T188S, D235N, E261V, V380I, and G223D). Exposure to short-term shock concentrations of vancomycin promotes the formation of heteroresistance in both MRSA and MSSA. Formation of VISA phenotypes is possible during therapy with vancomycin.

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