bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immunohistochemical Identification and Electron Microscopic Study on Early Migrating Neural Crest Cells in the Chick Embryo
Authors: Monteagudo de la Rosa M , González-Santander Martínez M , Martinez Cuadrado G , González Santander R 
Published: July 2020

Abstract
Just after neural fold fusion to form the neural tube, neural crest cells detach from the neural crest, a transient structure located in the dorsal region of the neural tube. Neural crest cells migrate and differentiate into many structures and cells. But the underlying controls of this detachment and initiation of emigration are unknown. Neural crest cells are usually not morphologically distinct from the adjacent neural epithelium (neural tube) and epidermal ectoderm (epiblast) flanking them. We are combining morphological and immunohistochemical approaches to study neural crest cells in their early stage of detachment from the neural crest.
Hamburger and Hamilton (1951) stages 9 to 12 White Leghorn chick embryos. Fixation in 2.5% glutaraldehyde - 0.5% tanic acid and postfixation in 1% osmium tetroxide. Embryos contrasted in bloc using uranyl acetate and embedded in araldite. Semithin transversal sections stained with toluidine blue for light microscopy. Ultrathin sections contrasted with lead citrate.
Sclerotome Mitotic Activity in Stage 19 Chick Embryo Braquial Somites
Authors: González-Santander Martinez M , Monteagudo de la Rosa M , Martinez Cuadrado G , González Santander R 
Published: July 2020

Abstract
Somite disintegration begins with the disruption and dispersion of cells in its ventromedial region, that upon detaching from the somite form a defined group of cells called “sclerotome”. The sclerotome is formed by scleroblasts that originate paraxial segments. Scleroblasts disperse and migrate forming the “sclerotomal mesenchyma”. This sclerotomal mesenchyma, in its evolution and cell differentiation, will give rise to skeletal tissues. One of the first features of the scleroblast is the production of extracellular matrix rich in hialuronic acid that facilitates the spreading of filopodia and the migration of the sclerotome. Sclerotome development is closely associated to the microenvironment created by the extracellular matrix in which scleroblasts are located. Hialuronic acid is found in the ample intercellular spaces occupied by the hydrated matrix.
White Leghorn chick embryos at H.H. stages 9 to 12 were fixed in 2.5% glutaraldehyde, postfixed in 1 % osmium tetroxide and embedded in araldite. Semithin transversal sections were stained with toluidine blue and visualized under the light microscope to locate the sclerotome.
Rolling Circle Amplification of Cyclizable Dna Probes by ∅29 Dna Polymerase: A Tool for in Situ Single-Copy Gene Detection.
Authors: Lizardi Paul M , Bray-Ward Patricia , Ward David C 
Published: July 2020

Abstract
Oligonucleotide probes that can be cyclized by ligation (“padlock probes”) provide a very high degree of recognition specificity. Nilsson et al. have demonstrated the used of padlock probes for the cytological localization of alphoid repeats in chromosome 12. We have been extending the use of padlock probes to the detection of single copy sequences, and with this in mind have explored the amplification of DNA circles.
We designed a primer complementary to the arbitrary backbone (non-probing) sequence of a 92-base closed circular probe oligonucleotide and investigated the kinetics of rolling circle replication. Using the highly processive, strand-displacing DNA polymerase of phage ∅29 (kindly provided by Dr. Margarita Salas, CSIC, Madrid, Spain) we demonstrated that several hundred tandem copies of the circular oligonucleotide are generated in a few minutes of incubation at 32°C. Because the amplified DNA remains hybridized to the circle in a rolling circle reaction, this method of amplification offers unique advantages for in situ gene detection since the amplified DNA can not diffuse away from the site of synthesis.
New Insights Into the Three-Dimensional Structure of the Nucleus and Chromosomes
Authors: Sedat J , Marshall W , Dernburg A , Fung J , Agard D 
Published: July 2020

Abstract
Recent methodology, to be described, now makes possible specific localization and analysis of genetic loci within 3-Dimensional interphase nuclei in intact cells and tissues with minimal perturbation of the chromosome structure (Dernburg and Sedat, 1997). These techniques define genetic loci that specifically interact with the nuclear envelope and interior structures; we are able to map all loci to highly localized 3-dimensional positions within Drosophila embryonic nuclei (Marshall et al, 1996). S-Dimensions-as-a-function-of-time (4-D) studies of live nuclei, from Yeast and Drosophila, allow dynamic chromosome interactions to be probed and quantitated. Our results suggest a very dynamic but highly determined and organized nucleus. Using these approaches, we can now study specific mechanisms leading to homologue chromosome pairing and position-effect variegation (Dernburg et al., 1996).
Structural Analysis of Large-Scale Chromatin Organization
Authors: Belmont A S , Li G , Sudlow G , Tumbar T , Strukov Y , Basu S , Delaney A 
Published: July 2020

Abstract
Our laboratory is interested in understanding how 10 and 30 nm chromatin fibers fold to form interphase and mitotic chromosomes. Experimentally this has been a very difficult problem to investigate due to a number of technical difficulties. A common approach to this level of chromatin organization has been to use protein extraction conditions which experimentally “unravel” the native chromosome architecture. The difficulty with this approach is separating in vitro produced artifacts from remnants of in vivo structure.
As an alternative strategy we are focusing on changes in interphase chromosome structure during cell cycle progression and initiation of transcription or DNA replication, with the goal of identifying intermediates in the pathway of chromosome condensation or decondensation. A key element of this strategy is preserving chromosome structure as close as possible to its in vivo structure while using 3-dimensional light and electron microscopy reconstruction methods to “computationally” unravel native chromosome structure.
Laser Scanning Microscopy Applied to Studies of the Cell Cycle.
Authors: Luther Ed , Kamentsky Louis A 
Published: July 2020

Abstract
Non-confocal Laser Scanning Microscopy (LSCM) was developed to allow applying the tenents of flow cytometery to specimens attached to a microscope slide (1). Areas of the slide are scanned, fluorescently labled cells are automatically segmented, and a list of features for each cell is calculated and stored in a list mode data file. Figure 1 shows a block diagram of the LSCM. A collimated laser beam scans in the y direction, and values from photomultiplier and photodiode detectors are digitized to.25 micron resolution. The automated stage advances in.5 micron steps in the x direction. When cascading memory banks are filled, the “image” is segmented. Figure 2 shows contours drawn as part of the segmentation process. The innermost contour is drawn around pixels that exceed a predetermined threshold, and is used to define events. Other contours are used to define integration areas, background calculation and correction, and integrating nuclear vs. peripheral fluorescence areas.
Scanning Electron Microscopic Study of Flowing Erythrocytes in Hepatic Sinusoids as Revealed by “in Vivo Cryotechnique”
Authors: Terada N , Fujii Y , Kato Y , Ueda H , Baba T , Ohno S 
Published: July 2020

Abstract
The flowing behavior of individual erythrocytes in blood vessels is usually determined by their deformability, which is controlled mainly by the nature of their interior constituents and the flexibility of their surface membrane. Moreover, the physical behavior of erythrocytes passing through capillaries has been examined in vivo by light microscopy. However, little has been known about ultrastructural changes of such erythrocyte shapes flowing in blood vessels in vivo. Recently, a new technique was developed for freezing cells and tissues in vivo without stopping the blood supply, which was referred to as “in vivo cryotechnique”.This method has been also suitable for obtaining informations about dynamic morphological changes.
Seven female Balb/c mice were anesthetized peritoneally with sodium pentobarbital (100μg/g body weight), and their abdomen was opened through a pararectus incision. For artificial cardiac arrest, some mice were anesthetized with an excessive dose of the anesthetic (500μg/g body weight), their respiration and heart-beat were completely stopped, and the following procedures were done within one minute. A liver was put on a plastic plate without disturbance of blood circulation, and the “in vivo cryotechnique” was performed. Briefly, a cryoknife was pushed into the liver as fast as possible and the tissue was immediately poured with liquid isopentane-propane mixture (-193°C) (Fig.la,b).
Development of a 3-Dimensional Internal Structure Microscope (3D-ISM) for the Observation to Biological Organisms.
Authors: Yokota Hideo , Kudoh Ken-ichi , Sato Kahei , Higuchi Toshiro 
Published: July 2020

Abstract
We developed a new type 3-Dimensional Internal Structure Microscope (3D-ISM) for the observation of internal structures of samples. The internal structure of a sample is obtained by cutting it into thin slices and observing the cutting side continuously while cutting. The position of the camera, as well as the sample position are fixed. Therefore there is no shift between the sections, and this system can obtain a true color image of the sample, which is a high resolution and a high-quality three-dimensional image compared with X-ray CT and MRI. After repeatedly slicing a sample, the digital image data from the sectional views is transferred to a computer, where 3-dimensional images of the internal structure of the sample are reconstructed. Using this system we analyzed many biological organisms. In this paper, a mouse specimen has been cut and the 3-dimensional images are shown.
This article presents the outline of the device and the principle of the observation. FIG.l shows a corresponding block diagram and Fig. 2 a schematic view of the 3D-ISM.
JSR and EJSR in the Finch Heart: Morphometry by Serial Sections.
Authors: Sommer JR , High T , Nassar R , Taylor I 
Published: July 2020

Abstract
“Coupling(s)” (Fig. 1) are structure complexes in cardiac muscle consisting of junctional SR (JSR) tightly apposed to the cytoplasmic side of the plasmalemma. They are either peripheral (PC; when on the cell surface) or interior (IC; when on transverse tubule(s), TT). The JSR is a store for calcium (Ca)-release through Ca channels/ryanodine receptors in junctional processe(s) (JP) on the JSR surfaces. Action potential(s) (AP) for excitation-contraction coupling translate, as mediated by L-type channels, into Ca-entry into a ˜ 20 nm junctional gap (JG) containing JP between plasmalemma and the JSR's junctional membrane proper. In mammalian cardiac myocyte(s) (CM), where IC are ubiquitously distributed along TT at Z-bands, an AP quickly effects almost simultaneous global contraction, even in the center of cells of large diameter, whence CICR can be viewed as a one-step event between Ca-entry and JSR Ca-release from couplings. Avian CM, however, have no TT and, thus, only PC.
Presence of Caveolae in the Granular Epithelial Cells of Rabbit Urinary Bladder
Authors: Mia AJ , Oakford LX , Yorio T 
Published: July 2020

Abstract
Previously, we reported the presence of caveolae, clathrin-coated pits and vesicles in toad urinary bladder granular epithelial cells, and in smooth muscle and endothelial cells. Since then we investigated the occurrence of caveolae in the rabbit urinary bladder cells. Here we report for the first time the presence of caveolae and clathrin-coated pits and vesicles in the granular epithelial, smooth muscle and endothelial cells of rabbit urinary bladders.
Urinary bladder sacs were surgically removed from doubly pithed toads and anaesthetized rabbits, and allowed fixation for 1 hr in 2% glutaraldehyde in PIPES buffer. These bladder tissues were divided for scanning (SEM) and transmission electron microscopy (TEM) for comparative analysis. A postfixation using 1% osmium tetroxide was carried out for 1 hr. Tissues were appropriately processed for SEM and TEM observations. Ultrathin sections, made with a diamond knife, were taken on bare nickel grids and then exposed to uranyl acetate and lead citrate for viewing in the TEM.
Immunohistochemical Evidence for Subclasses of Interstitial Cells of Cajal Associated with the Deep Muscular Plexus in Rat Small Intestine
Authors: Yunker AMR , Roth KA 
Published: July 2020

Abstract
Interstitial cells of Cajal (ICCs) were first described as primitive neurons found within organs innervated by autonomie nerves. In the gut, ICCs are juxtaposed among enteric nerve fibers and smooth muscle cells, suggesting they may modulate enteric neurotransmission and affect motility. The recent discovery of neurokinin-1 receptor (NKrl)-like immunoreactivity (ir) on ICCs has strengthened this hypothesis. This study compared the distribution of NKlr-ir to the staining patterns of other reported markers of ICCs including cholera toxin subunit b (CTB), neuron specific enolase (NSE), NADH diaphorase, NADPH diaphorase, nitric oxide synthase (NOS), and vimentin. Albino male rats were anesthetized and whole mount preparations of myenteric plexus-longitudinal muscle with attached circular muscle were dissected. ICCs were stained using multi-label techniques and cells were visualized with a Sarastro 2000 confocal laser scanning microscope equipped with Image Space software.
In the small intestine, ICCs associated with circular muscle, but not longitudinal muscle, expressed NKlr-ir.
Microcysys in the Posteroventral Cochlear Nucleus of the Gerbil by Scanning Electron Microscopy
Authors: Yu SM , Lee CI 
Published: July 2020

Abstract
Microcysts are most evident in the posteroventral and anteroventral cochlear nucleus (PVCN & AVCN) of the gerbil. They are reported as a neurodegenerative disorder or spongioform degeneration or a dynamic process related to the degree of auditory stimulation in the cochlear nucleus of the gerbil. Little information is avalable on the origin and formation of microcysts in the cochlear nucleus of the gerbil. The aim of this study was to investigate the internal morphologic changes of microcysts in the gerbil PVCN during postnatal development by scanning electron microscopy.
The mongolian gerbil, Meriones unguiculatus, were sacrificed by cardiac perfusion of a saline nitrite flush, followed by a 3% glutaraldehyde in 0.1M phosphate buffer. After fixation the brain were washed in 0.1M phosphate buffer,embedded in 5% agar, vibratome-sliced through the cochlear nucleus, and then postfixed in the 1% osmium tetroxide in 0.1M phosphate buffer for one hour. The sectioned tissues were dehydrated in a graded ethanol series to absolute ethanol and transferred to liquid carbon dioxide for critical point drying.
Morphometry of Synapse and Granule Cell Changes in the Hippocampus of Aging Fischer 344 Rats
Authors: White S L , Gatlin C L , Horn J W , Shannon H E , Smith W C , Jordan W H 
Published: July 2020

Abstract
Morphologic changes in Alzheimer’s disease (AD) include a decrease in synapse number while the surviving synapses are increased in size by a process known as compensatory synaptogenesis. There is disagreement among investigators as to whether the synapse changes observed in AD in humans also occurs in the aging rat. The hippocampus, plays a significant role in learning and memory in both humans and rats and is known to be particularly susceptible to cell loss associated with aging. s In the rat hippocampus, age-related synaptic density declines as much as 27% have been reported by some authors, while other investigators have failed to detect a change in synapse number with age. A secondary factor in the total number of synapses in the dentate gyrus is the number of granule cells. Proliferation or regeneration (neurogenesis) of hippocampal granule cells is known to occur well into the adult life of the rat. The goal of the current study was to further explore age-related changes in rat hippocampal synapses and granule cells using the disector morphometry method.
An Integrated Biological Imaging Facility: Capabilities of the Biological Microscopy and Image Reconstruction Resource
Authors: Frank J , Mannella CA , Rieder C 
Published: July 2020

Abstract
The Biological Microscopy and Image Reconstruction Resource (BMIRR) is operated by the Wadsworth Center as a national biotechnology resource, with funding through the NIH Center for Research Resources and from NSF. This biological imaging resource has evolved continuously over the past two decades. Early development focussed on correlative, same-cell light and electron microscopic techniques, combining the capabilities of video-enhanced light microscopy and high-voltage electron microscopy. A current area of development is electron microscopic tomography, whereby the full 3D capabilities of higher voltage (400-1200 KV) electron microscopy is brought to bear on biological problems. In particular, the recent development of techniques for merging projection data from two mutually perpendicular tilt series has permitted significantly improved resolution, reducing the missing wedge of information to a missing pyramid. Attention is now turning to optimization of conditions for applying tomography to frozen-hydrated specimens, using automated data collection on our cryo-IVEM. Combined with parallel advances in same-cell manipulation and viewing, the BMIRR provides biologists with a unique combination of imaging and computational tools for research into the 3D structure and dynamics that underly cellular processes (see figures and refs. 2-4).
Exploring Macromolecular Interactions at High Resolution Using Electron Cryomicroscopy at NCMI
Authors: Schmid MF , Sherman M B , Brink J , Jakana J , Kelsey M , Dougherty M , Chiu W 
Published: July 2020

Abstract
The National Center for Macromolecular Imaging (NCMI) is a resource supported by the National Center for Research Resources (NCRR) of NIH. Its mission is to advance electron imaging of macromolecular assemblies to near atomic resolution. We have focused on biological assemblies which are too large or too complex to be studied by conventional x-ray crystallography or NMR spectroscopy techniques. As is the case with all the NCRR-supported facilities, we also conduct methodology development, collaboration, service, technology dissemination and training.
The objectives of this Research Resource are to develop the technology of high resolution electron cryomicroscopy of biological macromolecules, assemblies and crystals in an integrated approach that includes specimen preparation, hardware and software development. A current methodology development includes the characterization of the 1k x 1k slow-scan CCD camera for both electron diffraction and imaging of ice-embedded specimens. These studies have defined the advantages and limitations of the CCD camera for electron crystallographic analysis. Another core research project deals with the problems of specimen movement due to the electron beam and/or charging and seeks to minimize these phenomena. Our efforts have resulted in a better understanding of the physics of charging. We have modified a Gatan ion-beam coater so that we can apply a thin layer of carbon onto ice-embedded specimens.
Tissue Compatibility of Silicon Microfabricated Probes Inserted into the Brain
Authors: Turner J N , Shain William , Szarowski D H , Anderson M , Martins S , Davis R , Craighead H G , Isaacson M 
Published: July 2020

Abstract
The application of nano- and microfabricated devices based on silicon electronics technology is an emerging interdisciplinary area combining engineering and biology. The placement of electrically active probes in damaged or diseased tissues of the central nervous system could have enormous impact on the health and quality of life of large numbers of individuals by restoring lost function, or by treating or controlling disease states. Such probes have been fabricated at a high level of engineering sophistication. Unfortunately, when inserted into the brain a tissue reaction is initiated forming a scar that surrounds and electrically isolates the probe within a few weeks. This reaction is thought to primarily involve glial cells, and is undoubtedly dominated by the bulk surface of the probes which have a silicon oxide layer on top of single crystal silicon.
Model probes (Fig. 1) were microfabricated by photolithography with a 1×1mm tab used for gripping and inserting probes.
Neurological Research and Shared Imaging Resources at the National Institutes in Okazaki, Japan
Authors: Hama Kiyoshi 
Published: July 2020

Abstract
The Okazaki National Research Institutes, consisting of three cooperative research Institutes, the Inst. of Molecular Science (NIMS), the Inst. of Basic Biology (NIBB) and the Inst. of Physiological Sciences (NIPS), employs about 700 researchers and 200 full time technical staff. To support cooperative research projects, ONRI has several special shared research facilities in addition to those conventionally used for bioscience laboratories: a 1000 kV high voltage electron microscope designed for three dimensional morphometry and computer tomography of biological structures, a 300 kV ultra cryoelectron microscope equipped with an energy filtering system, which is now being set up, and a two photon excitation laser confocal microscope. In addition, there is an MRI, a rapid MRI, SQUID with 37 + 37 channels, and micro SQUID for non-invasive examination of brain function in human and experimental animals. A UVSOR (UV synchrotron orbital radiation) lab., a laser lab., and an ultra-low temperature lab. are available for neuroscience collaboration with Japanese and international scientists.
Neurocartography: Geometry and Biology of the Central Nervous System
Authors: Tretiak O J , Nissanov J 
Published: July 2020

Abstract
The central nervous system of a vertebrate organism exhibits a very complex spatial organization structure and function. These relationships are the subject of intense study for over a century, and recent developments in imaging have attracted ever increasing effort devoted to the understanding of brain function. One can produce any number of quantitative images that provide maps of the anatomy and function of nerve tissues. For example, autoradiography can yield functional images (2-deoxy glucose), maps of neurotransmitters receptors (over 100 know types), and gene expression labeled with complementary mRNA (in-situ hybridization). Immunohistochemistry produces maps of a large variety of neuroactive components, such as transmitters.
To illustrate a typical procedure, we describe the mapping of brain function with 2-deoxy glucose (2DG). A rat performing some task is injected with a solution of 2DG radiolabeled with 14C¨ Subsequently, the animal is sacrificed, the brain is cryosectioned (ca. 20 μm), and contact autoradio-grams of these sections are made on X-ray film.