scholarly journals THE FINE STRUCTURE OF NERVE CELL BODIES AND THEIR MYELIN SHEATHS IN THE EIGHTH NERVE GANGLION OF THE GOLDFISH

1961 ◽  
Vol 9 (4) ◽  
pp. 853-877 ◽  
Author(s):  
Jack Rosenbluth ◽  
Sanford L. Palay
Keyword(s):  
Schwann Cell ◽  
Nerve Cell ◽  
Single Layer ◽  
Intermediate Form ◽  
Cell Cytoplasm ◽  
Eighth Cranial Nerve ◽  
Myelin Sheaths ◽  
Nerve Ganglion ◽  
The One ◽  
Internodal Segment

The eighth cranial nerve ganglion consists of bipolar nerve cell bodies each occupying part of an internodal segment. The perikaryal sheaths range from a single layer of Schwann cell cytoplasm on the smallest cells to typical thick compact myelin on the largest. On most perikarya, the sheath displays an intermediate form, consisting of multiple layers of Schwann cell cytoplasm (loose myelin), or of loose and compact myelin continuous with each other. Internodes beyond the one containing the cell body bear only compact myelin. In loose myelin the thickness of each layer of Schwann cell cytoplasm is about 100 A. It may be much greater (∼ 3000 A) particularly in the outermost layers of the sheath, or the cytoplasm may thin and even disappear with formation of a major dense line. The cytoplasmic layers are separated from each other by a light zone, 40 to 200 A wide, which in its broader portions may contain an intermediate line. Desmosomes sometimes occur between lamellae. In addition to the usual organelles, the perikaryal cytoplasm contains granular and membranous inclusions. Large cells covered by compact myelin have a consistently higher concentration of neurofilaments, and some of the largest cells, in addition, show a reduced concentration of ribosomes. The functional significance and possible origins of perikaryal myelin sheaths are discussed.

scholarly journals THE FINE STRUCTURE OF ACOUSTIC GANGLIA IN THE RAT

1962 ◽  
Vol 12 (2) ◽  
pp. 329-359 ◽  
Author(s):  
Jack Rosenbluth
Keyword(s):  
Fine Structure ◽  
Schwann Cell ◽  
Nerve Cell ◽  
Ganglion Cells ◽  
Cell Type ◽  
High Concentration ◽  
Cell Sheets ◽  
Adult Rat ◽  
Myelin Sheaths ◽  
Cytoplasmic Organelles

Nerve cell bodies in the spiral and vestibular ganglia of the adult rat are surrounded by thin (about ten lamellae) myelin sheaths which differ in several respects from typical axonal myelin. In some instances lamellae surrounding perikarya appear as typical major dense lines, and in others as thin Schwann cell sheets in which cytoplasm persists. Discontinuities and irregularities appear in the structure of perikaryal myelin. Lamellae may terminate anywhere within the sheaths; they may bifurcate; they may reverse their direction; or they may merge with each other. The number of lamellae varies from one part of a sheath to another. In addition, the myelin of a single perikaryal sheath may receive contributions from more than one Schwann cell, which overlap and interleave with each other. The ganglion cells are of two types: those which are densely packed with the usual cytoplasmic organelles but have few neurofilaments (granular neurons), and those which exhibit large areas containing few organelles but have a high concentration of neurofilaments (filamented neurons). The latter cell type is ensheathed by myelin which is generally more compact that that surrounding the former. The formation and the physiologic significance of perikaryal myelin are discussed.

scholarly journals Immunocytochemical localization of P0 protein in Golgi complex membranes and myelin of developing rat Schwann cells.

1981 ◽  
Vol 90 (1) ◽  
pp. 1-6 ◽  
Author(s):  
B D Trapp ◽  
Y Itoyama ◽  
N H Sternberger ◽  
R H Quarles ◽  
H Webster
Keyword(s):  
Schwann Cell ◽  
Schwann Cells ◽  
Golgi Complex ◽  
Cell Cytoplasm ◽  
Adult Rats ◽  
Thin Sections ◽  
Myelin Sheaths ◽  
Transmission Electron ◽  
P0 Protein ◽  
Developing Rat

P0 protein, the dominant protein in peripheral nervous system myelin, was studied immunocytochemically in both developing and mature Schwann cells. Trigeminal and sciatic nerves from newborn, 7-d, and adult rats were processed for transmission electron microscopy. Alternating 1-micrometer-thick Epon sections were stained with paraphenylenediamine (PD) or with P0 antiserum according to the peroxidase-antiperoxidase method. To localize P0 in Schwann cell cytoplasm and myelin membranes, the distribution of immunostaining observed in 1-micrometer sections was mapped on electron micrographs of identical areas found in adjacent thin sections. The first P0 staining was observed around axons and/or in cytoplasm of Schwann cells that had established a 1:1 relationship with axons. In newborn nerves, staining of newly formed myelin sheaths was detected more readily with P0 antiserum than with PD. Myelin sheaths with as few as three lamellae could be identified with the light microscope. Very thin sheaths often stained less intensely and part of their circumference frequently was unstained. Schmidt-Lanterman clefts found in more mature sheaths also were unstained. As myelination progressed, intensely stained myelin rings became much more numerous and, in adult nerves, all sheaths were intensely and uniformly stained. Particulate P0 staining also was observed in juxtanuclear areas of Schwann cell cytoplasm. It was most prominent during development, then decreased, but still was detected in adult nerves. The cytoplasmic areas stained by P0 antiserum were rich in Golgi complex membranes.

scholarly journals Incorporation of newly formed lecithin into peripheral nerve myelin.

1976 ◽  
Vol 68 (3) ◽  
pp. 480-496 ◽  
Author(s):  
R M Gould ◽  
R M Dawson
Keyword(s):  
Sciatic Nerve ◽  
Schwann Cell ◽  
Peripheral Nerve ◽  
Intraperitoneal Injection ◽  
Axoplasmic Transport ◽  
Cell Cytoplasm ◽  
Neuronal Perikaryon ◽  
Myelin Sheaths ◽  
Adult Mice ◽  
Frog Sciatic Nerve

Radioactive choline was used to study the metabolism and movement of choline-containing phospholipids in peripheral nerve myelin of adult mice. Incorporation at various times after intraperitoneal injection was measured in serial segments of sciatic nerve as well as in myelin isolated from those segments. At no time (1 h to 35 days) could a proximal-distal difference in the extent of labeling be demonstrated. This finding suggests that incorporation of precursor choline phospholipids into nerve membranes is a local event, with little contribution from the neuronal perikaryon via axoplasmic transport. Autoradiographic investigations were undertaken to elucidate the pattern of movement of radioactive choline-labeled phospholipids, predominantly lecithin, into the myelin sheaths of the sciatic nerve. A sequence of autoradiographs was prepared from animals sacrificed between 20 min and 35 days after a microinjection of precursor directly into the nerve. Analysis of these autoradiograms revealed that labeling is initially concentrated in the Schwann cell cytoplasm. Later, the label moves first into the outer regions of the myelin sheaths and is eventually distributed evenly throughout the inner and outer layers of the sheath. At no time is there a build-up of label in the axon. The rate of uptake of precursor and subsequent redistribution of lecithin into the myelin were also examined in frog sciatic nerve (18 degrees C). Both uptake and redistribution processes were considerably slower in the cold-blooded animal.

scholarly journals Extraction of causal relations based on SBEL and BERT model

Database ◽  
2021 ◽  
Vol 2021 ◽  
Author(s):  
Yifan Shao ◽  
Haoru Li ◽  
Jinghang Gu ◽  
Longhua Qian ◽  
Guodong Zhou
Keyword(s):  
State Of The Art ◽  
Causal Relation ◽  
Relation Extraction ◽  
The Other ◽  
Biomedical Text ◽  
Intermediate Form ◽  
Biomedical Text Mining ◽  
Causal Relations ◽  
The One ◽  
Stage 1

Abstract Extraction of causal relations between biomedical entities in the form of Biological Expression Language (BEL) poses a new challenge to the community of biomedical text mining due to the complexity of BEL statements. We propose a simplified form of BEL statements [Simplified Biological Expression Language (SBEL)] to facilitate BEL extraction and employ BERT (Bidirectional Encoder Representation from Transformers) to improve the performance of causal relation extraction (RE). On the one hand, BEL statement extraction is transformed into the extraction of an intermediate form—SBEL statement, which is then further decomposed into two subtasks: entity RE and entity function detection. On the other hand, we use a powerful pretrained BERT model to both extract entity relations and detect entity functions, aiming to improve the performance of two subtasks. Entity relations and functions are then combined into SBEL statements and finally merged into BEL statements. Experimental results on the BioCreative-V Track 4 corpus demonstrate that our method achieves the state-of-the-art performance in BEL statement extraction with F1 scores of 54.8% in Stage 2 evaluation and of 30.1% in Stage 1 evaluation, respectively. Database URL: https://github.com/grapeff/SBEL_datasets

Three-Dimensional Microfabrication System for Biodegradable Microdevices With High-Resolution and Bio-Applicability

2005 ◽  
Author(s):  
Akira Yamada ◽  
Fuminori Niikura ◽  
Koji Ikuta
Keyword(s):  
Tensile Strength ◽  
Biodegradable Polymers ◽  
Conventional Method ◽  
Three Dimensional ◽  
Single Layer ◽  
Batch Process ◽  
Potential Applications ◽  
A Cell ◽  
The One ◽  
Almost All

Biodegradable polymers are employed in medicine and its further application is expected with eagerness. But the lack of an appropriate processing method retards the progress. To overcome this problem, we have developped a novel three-dimensional microfabrication system. The system design allows us the processing of the free three-dimensional micro-level forms by stacking up melted polymers from the nozzle. Different from the conventional method, we adopted a batch process to supply materials in order to eliminate the prior process that required toxic solvents. In addition, it is possible to handle almost all biodegradable thermoplastic resins by adopting this system. A single layer from the piled-up layers of extruded lines was observed to evaluate the resolution. The lateral and depth resolutions attained are 40 μm and 45 μm, respectively. Biodegradable polymers enable three-dimensional microstructures such as micro-pipes, micro-bends, and micro-coil springs to be manufactured in less than 15 min. The biocompatibility of the newly fabricated structure was evaluated using a cell line (PC12). For this purpose, a small vessel, with a transparent base, was fabricated using PLA and cells were cultivated in it. The results were then compared with the results obtained using the standard method. The mechanical strength of our microstructures was evaluated using a tensile strength test. The tensile strength of the microstructure was lower than the one obtained from the conventional method, but has enough strength for fabrication of medical devices. Our system renders it possible to produce toxic-free, as well as transparent and leakage-free devices. Our system is expected to have potential applications in optimum design and fabrication of implantable devices, especially in tissue engineering.

scholarly journals Synthesis of BODIPY-Amino Acids and the Potential Applications as Specific Dyes for the Cytoplasm of Langerhans β-Cells

2021 ◽  
Author(s):  
Jorge Aguilera ◽  
Víctor García-González ◽  
Manuel Alatorre-Meda ◽  
Eustolia Rodríguez-Velázquez ◽  
Ignacio Rivero
Keyword(s):  
Amino Acids ◽  
Photophysical Properties ◽  
Fluorescence Emission ◽  
Dual Fluorescence ◽  
Β Cells ◽  
Cell Cytoplasm ◽  
Specific Staining ◽  
Cell Staining ◽  
Potential Applications ◽  
The One

In this work, we explored the synthesis of 4,4-difluoro-4-bora-3a,4a-diazas-indacene (BODIPYs) bound to five different amino acids (BODIPY-FAA) (glycine, alanine, leucine, phenylalanine, and tyrosine) (amino group is kept protected with fluorophore Fmoc) and evaluated these conjugates in terms of (i) their photophysical properties and (ii) their potential application as cell staining agents of suspension and adherent cells at healthy and stress conditions. In general, all synthesized BODIPY-FAA (3a-3e) were found to emit fluorescence in the blue and green regions of the spectrum (depending on the solvent conditions). However, BODIPY-FTyr(trt) (3e) showed the best molar extinction coefficient (ε = 28,198 M-1 cm-1) and quantum yield (Φ = 0.17). Biologically speaking, all synthesized conjugates demonstrated a selective affinity for the cytoplasm of Langerhans β-cells employed as a model, being the BODIPY-FLeu conjugate the one displaying the highest observed intensity. As such, our results reveal the BODIPY-FAA as a novel attractive tool for the specific staining of the cell cytoplasm, demonstrating not only a dual fluorescence emission but also a sensing capability to recognize different cell states.

Selective withdrawal from a stably stratified fluid

1968 ◽  
Vol 32 (2) ◽  
pp. 209-223 ◽  
Author(s):  
I. R. Wood
Keyword(s):  
Single Layer ◽  
Layered System ◽  
Volume Discharge ◽  
Layer System ◽  
Minimum Width ◽  
Theoretical Predictions ◽  
Small Rise ◽  
Self Similar ◽  
The One ◽  
Dead Water

In this paper a reservoir connected through a horizontal contraction to a channel is considered. Both the reservoir and the channel are considered to contain a stable multi-layered system of fluids. The conditions under which there is a flow in only one layer, and the depth in this flowing layer decreases continuously from its depth in the reservoir to its depth in the channel, give the maximum discharge that can be obtained with a flow only from this single layer. For this case the volume discharge calculations are carried out at a single section (the section of minimum width). Where there are velocities in only two layers and the depth in each of these layers decreases continuously from their depths in the reservoir to their depths in the channel, the theory involves computations at two sections in the flow. These are the section of minimum width and a section upstream of the position of minimum width (the virtual point of control). For this flow it is shown that the solution is the one in which the velocity and density distributions are self similar and that the depths of the layers at the point of maximum contraction are two-thirds of those far upstream. It is then shown that for any stable continuous or discrete density stratification in the reservoir a self similar solution will satisfy the conditions for the depths of the flowing layers to decrease smoothly from the reservoir to downstream of the contraction. Again the ratio of the depth at the contraction to that far upstream is two-thirds.When there is a very large density difference between the fluid in the lower dead water and that in the lowest flowing streamline then this streamline becomes horizontal and may be considered as a frictionless bed. The flow when the bed is not horizontal but where there is a small rise in the channel at the position of maximum contraction is considered for the case where two discrete layers flow under a volume of dead water. In this case the velocity and density profiles are not self similar.Experiments have been carried out with a contraction in a flume for the withdrawal of two discrete layers from a three layer system and the withdrawal from a fluid with a linear density gradient. In both cases the reservoir and channel bed and hence the lowest streamline was effectively horizontal. These experiments confirmed the theoretical predictions.

Crystalloid Inclusions in the Schwann Cell Cytoplasm

1973 ◽  
Vol 148 (4) ◽  
pp. 402-406 ◽  
Author(s):  
C.N. Sun ◽  
H.J. White ◽  
G. Lucas
Keyword(s):  
Schwann Cell ◽  
Cell Cytoplasm ◽  
Crystalloid Inclusions

A Simple Approach for Estimating the First Resonance Peak of Layered Soil Profiles

2018 ◽  
Vol 12 (01) ◽  
pp. 1850005 ◽  
Author(s):  
Haizhong Zhang ◽  
Yan-Gang Zhao
Keyword(s):  
Soil Profile ◽  
Single Layer ◽  
Resonance Peak ◽  
Layered Soil ◽  
Soil Profiles ◽  
Simple Method ◽  
Amplification Ratio ◽  
Local Site ◽  
The One ◽  
Input Motion

The first resonance peak, Gs1, represents the amplification ratio of seismic motion when resonance between input motion and the local site occurs. The Gs1 is important for understanding amplification characteristics of local site, thus it has been adopted for evaluating site effects in the Japanese Seismic Code. Herein, a simple method for estimating the Gs1 of layered soil profiles is proposed. By replacing a multi-layer soil profile on bedrock with an equivalent one-layer soil profile, the Gs1 and fundamental period are easily obtained. To realize the one-layer profile, we develop a procedure to replace a two-layer soil profile on bedrock with an equivalent single-layer profile. This procedure is then applied successively to a multi-layer soil profile to obtain an equivalent single-layer soil profile. The validity of the proposed method is demonstrated by evaluating 67 representative sites. The results obtained using the proposed procedure agree well with those produced by the wave propagation method.

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