bluuebunny/crossref_metadata_2025_split huggingface dataset:
Scanning Electron Microscopic structure and function of the fore-gut of Indian fresh water prawn,Macrobrachium lamarrei H.M. Edwards(Decapoda-Palaemonidae)
Authors: Shukla Sanjive , Sharma U. D. 
Published: June 2020

The fore-gut structure of certain crustaceans is well documented. However, data on palaemonidae are scanty. The present work has been carried out on the ultrastructure of the fore-gut in relation to feeding and food movements inM. lamarrei, an omnivorous animal. The fore-gut was dissected out and slit open in various individuals for SEM studies and processed. Samples were observed under an SEM (JEOL JSM 35C) and photographed.The number, size, shape, and arrangement of bristles vary in different zones, which is devoid of gastric mill. Bristles are either simple or compound, and are present in groups at the entrance of the esophagus from the buccal cavity, on esophageal folds, and on the wall and floor of the cardiac stomach (Figs. 1-10). The simple smallest bristles (35-53 μm) are on the esophageal folds; simple as well as compound bristles (275 μm) are present on the cardiac luminal surface.
Freeze-fracture Electron Microscopic observations on the effects of sulphydryl group reagents on human erythrocyte membranes
Authors: Benga Gheorghe , Brain Anthony , Pop Victor I. , Wrigglesworth John 
Published: June 2020

The intra-membrane particles (IMPs) observed on the fracture face of frozen erythrocyte membranes are thought to correspond primarily to “band 3” tetramers or dimers. Some recent studies correlating the inhibition of water diffusion in erythrocytes by p-chloromercuribenzene sulfonate (PCMBS) with the binding of 203Hgto erythrocyte membrane proteins has enabled band 3 and the polypeptides in band 4.5 to be identified as the proteins associated with the channels for water permeation in human erythrocytes. A further characterization of the effects of the incubation of human erythrocyte membranes with PCMBS and N-ethylmaleimide (NEM) has been performed as previously described. Experimental conditions have been previously described.A comparison was made of the appearance of freeze-etched membranes of control erythrocytes and erythrocytes with the sulphydryl reagents. It was found that on many of the control and NEM-treated cells, small (50-100 nm) elevated patches could be seen (Fig. 1, 2 and 3). These are present on both fracture and etch faces and are devoid of any intramembrane particles. The patch elevations were never observed in the membranes of PCMBS-treated cells (Fig. 4).
Purification of the helical filaments appearing in mitochondria
Authors: Sasaki Hiroyuki , Kurioka Susumu , Misawa Takeyuki , Suzuki Teruo 
Published: June 2020

Helical filaments with characteristic morphology have been found exclusively in the outer compartment of mitochondria in the epithelial cells of renal proximal tubules of patients, and in the brain astrocytes, the ameloblasts and the epithelial cells of renal medullary tubules of the normal rats, and in the liver parenchymal cells of the rats with and without ethanol ingestion. Recently, the filaments with same helical structure found in the mitochondria of the certain parasite. Thus, the intramitochondrial helical filaments appeared widely in biological fields. However, the nature, origin and physiological significance of the helical filament are at present unknown. In the present study, to clarify the molecular arrangement of the helical filament, the filaments were purified from the mitochondriaof the liver of ethanol ingested rats in which have been confirmed to appear large amount of the helical filaments in mitochondria.Male S-D strain rats (6-week old) were used in the present study. Rat were given 30% ethanol for 90 days with oral administration. With conventional TEM observations, the helical filaments were frequently found in mitochondria of liver cells of the rat with ethanol ingestion (Fig. 1). For purification of the helical filaments, the mitochondria were isolated from ethanol ingested rats liver cells by slightly modified Bustamante et al. method. The isolated mitochondria were ruptured by osmotic breakage.
The application of freeze-fracture in the analysis of intercellular junctions in pleuro-pulmonary tumors
Authors: Mukherjee T. M. , Swift J. G. 
Published: June 2020

Thin section and freeze-fracture techniques have been used to examine the morphology of cell junctions in a variety of pleuro-pulmonary tumours with the aim of identifying features that may be of diagnostic importance or of significance in the development of the tumour. Freeze-fracture preparations are particularly useful for the analysis of cell junctions, since extensive face views of the interior of the cell membrane are exposed. This enables precise characterisation of the type of junctions present, their extent and their inter-relationships.Freeze-fracture replicas can reveal the presence of junctions that would be difficult or impossible to detect in thin sections. For example, desmosomes are a well-known feature in thin sections of squamous cell carcinomas, but these tumours may also have focal tight junctions and gap junctions (Figs. 1,2). The tight and gap junctions can occur separately (Fig.l), or in combination (Fig. 2). Similarly, in a recent study of a case of “Ewing’s sarcoma”, replicas showed the presence of unusual, elaborate focal tight junctions, a feature never suspected from the routine thin section studies of this tumour.
Morphometric analysis and autoradiography of the smooth endoplasmic reticulum during glycogen deposition in the fetal mouse hepatocyte
Authors: Shockey Breslin Joanette , Cardell Robert R. 
Published: June 2020

Analyses of adult hepatic glycogen deposition by numerous investigators have determined that the smooth endoplasmic reticulum (SER) proliferates immediately prior to glycogen deposition and during the early stages of glycogen accumulation, then decreases as glycogen levels reach their maximum, suggesting that SER participates in adult hepatic glycogen metabolism. Less is known regarding fetal hepatic glycogen synthesis and the participation of the fetal SER. The studies described here test the hypothesis that the SER functions in the synthesis of fetal hepatic glycogen. Quantitative analysis of SER and glycogen levels during hepatic glycogen synthesis tests the existence of a correlation between glycogen and SER. Newly deposited labeled glycogen is localized via autoradiography and the extent of association between labeled glycogen and SER quantified, establishing whether glycogen is necessarily deposited near membranes of SER.Fetal mouse livers were harvested at daily intervals between days 14 and 19 of gestation, immersion fixed in 2% glutaraldehyde, 2% paraformaldehyde, post-fixed in 1 % OsO4 dehydrated in EtOH and embedded in Epon 812. Semi-thin (0.5μm) and ultra-thin sections (60 nm) were prepared for morphometric analysis.2
On the cross-sectional shape of the cellulose crystallites in the tunicate Halocynthia papillosa
Authors: Revol J.-F. , Van Daele Y. , Gaill F. 
Published: June 2020

The only form of cellulose which could unequivocally be ascribed to the animal kingdom is the tunicin that occurs in the tests of the tunicates. Recently, high-resolution solid-state l3C NMR revealed that tunicin belongs to the Iβ form of cellulose as opposed to the Iα form found in Valonia and bacterial celluloses. The high perfection of the tunicin crystallites led us to study its crosssectional shape and to compare it with the shape of those in Valonia ventricosa (V.v.), the goal being to relate the cross-section of cellulose crystallites with the two allomorphs Iα and Iβ.In the present work the source of tunicin was the test of the ascidian Halocvnthia papillosa (H.p.). Diffraction contrast imaging in the bright field mode was applied on ultrathin sections of the V.v. cell wall and H.p. test with cellulose crystallites perpendicular to the plane of the sections. The electron microscope, a Philips 400T, was operated at 120 kV in a low intensity beam condition.
Effect of calcium on endospore ultrastructure
Authors: Stears Robin L. 
Published: June 2020

Clostridium sporogenes has been designated as a test species for the closely related but pathogenic Cl. perfringens. Cl. sporogenes possess a unique morphology. High resolution EM has not been applied and little is known about its calcium distribution, thus this study presents a morphological evaluation as well as data on calcium localization, which is considered important for endospore resistance.Cl. Sporogenes was grown on cooked meat/media. Sporulation was monitered using the malachite green method. After maximum sporulation the spores were harvested in deionized distilled water, heated for 20 minutes at 80°C to kill any remaining vegetative cells, washed 3 times with sterile deionized water and the stock suspension was stored at 2-8°C until needed. Aliquots of the spores were placed momentarily in warm agar prior to fixation then fixed in 3% gluteraldehyde (GCHO) in 0.1 M cacodylate buffer pH 7.4 to which Ca was deleted or with 1% CaCl.
Ultrastructural localization of cell-wall antigens in Paracoccidioides brasiliensis
Authors: Edwards M. R. , Samsonoff W. A. , Ostrander G. A. 
Published: June 2020

Paracoccidioides Brasiliensis is a pathogenic fungus responsible for a widespread systemic disease in Latin America. It grows at 25°C as a mold, but at 37°C produces veast cells. Previous ultrastructural studies revealed the eukaryotic structures of these cells. Here we present results from an immunoelectron-microscopic study using human antibodies from patients with paracoccidioidomycosis and rabbit anti-human IgG conjugated with gold particles (10 nm in diameter).Yeast cells were fixed with 0.2-0.5% glutaraldehyde with 2% formaldehyde in cacodylate buffer (pH 7.2) for 5 h at room temperature and at 4°C overnight; after buffer washings, with or without 0.5% saponin, the samples were osmicated, dehydrated and embedded in epoxy resins, according to standard methods. Thin sections were incubated with normal human serum (negative control) or with human antiserum (kindly provided by A. Restrepo-Moreno, Medellin, Colombia) and treated with immunogold probes according to published protocols.
The influence of lead at different concentration and pH on the ultrastructure of root cells from germinating soybean seeds
Authors: Crang Richard F. E. , Kuras Mieczyslaw , McQuattie Carolyn J. 
Published: June 2020

Environmental pollution of lead in the USA has become less of a serious problem with the advent of non-leaded petroleum products. However, other sources of organic and inorganic compounds with lead content and, (in many parts of the world) leaded fuels, are still employed which create health and environmental problems. The conditions by which lead uptake occurs in plants, its translocation and toxic effects have been demonstrated by various investigators.We have investigated the influence of lead on roots of germinating soybean (‘Williams’) seeds over the course of 48 hr treatments at atomic concentrations of 0.0, 250, 500 and 2,000 ppm. Imbibed seeds were placed on filter paper saturated with aqueous levels of PbCl2 adjusted to pH levels of 5.5, 3.5, and 2.5. Tissue slices about 1 mm behind the growing root tips were obtained and conventionally prepared for transmission electron microscopy. In most cases lead post-staining was not employed so as to not interfere with the presence of naturally-occurring lead deposits.
Characterization of beam-induced thinning and shrinkage of semi-thick sections in the HVEM
Authors: Kremer J.R. , O'Toole E.T. , Wray G.P. , Mastronarde D.M. , Mitchell S.J. , Mcintosh J.R. 
Published: June 2020

It is well known that irradiation of plastic sections in a conventional transmission electron microscope (cTEM) causes specimen thinning and distortion. Thinning has been observed in the cTEM using several embedding media, using methods such as shrinkage of ordered paracrystalline structures, and shrinkage of sections coated with colloidal gold markers. The total thinning observed in the cTEM (80kev) is 30-50% for thin sections of epon araldite, but similar data do not exist for the HVEM at 1000 kev. Here we describe beam induced thinning and shrinkage of 0.2um sections in the HVEM.Experiments were performed using 0.2um sections of EPOX 812/Araldite or LX112 with 15 nm and 30 nm gold particles affixed to either surface of the section. The sections were initially tilted to approximately 25° and irradiated with known dose rates. Micrographs were taken at different times between 0-20 minutes then the sections were tilted back to 0° for a reference micrograph.
Embedding of unfixed plant material in water-soluble resin: A simple preparation method for elemental analysis by ESI and EELS techniques
Authors: Lehmann Heiner , Kunz Ulrike 
Published: June 2020

The localization of elements in cells and tissues by electron spectroscopic imaging (ESI) or electron energy loss spectroscopy (EELS) can be realized only in very thin specimens in order to avoid multiple scattering of the electrons. Therefore the biological material has to be cut in thin 30 nm sections.The commonly used preparation procedure is a hydrous chemical fixation followed by dehydration, embedding in hydrophobic resin and ultrathin sectioning. The disadvantage of this procedure is the loss and/or dislocation of inorganic ions and other water-soluble substances. To overcome these difficulties the preferable preparation method is cryofixation in combination with cryosubstitution, but this is a very expensive and time-wasting procedure.Meanwhile, we established a more simplified preparation technique, which shows reasonable results on plant cells without large central vacuoles: The living cells were directly put into freshly mixed Nanoplast FB 101, a water-soluble melanine resin, and stored for 24 h at 20° C in a silca gel containing exsiccator.
Detection of elements by ESI and analysis of EEL spectra in alveolar macrophages prepared by slam-freeze molecular distillation processing
Authors: Godleski John J. , Stearns Rebecca C. , Katler Marshall , Hastings Cindy L. 
Published: June 2020

The capability to map the distribution of elements in relationship to ultrastructural cellular morphology has been a longstanding goal in anatomic research. With biologic materials, the technology for elemental detection is limited by the lack of retention of elements in ionic form during processing with liquid fixatives. Although we have been able to show that by selection of fixative and processing methods, 95% of cell associated iron remains with the cells after processing, we have not found an adequate general purpose liquid fixative to preserve ions in cells. Hence, we have turned to cryogenic methods which are more likely to retain intracellular ions.Alveolar macrophages were obtained from hamsters by saline bronchoalveolar lavage. The cells were centrifuged and resuspended in medium RPMI 1640 at a concentration of 1×108/ml. A 5 μl aliquot of the cell suspension was placed on an agar mount and instantaneously frozen using a Life Cell® CF-100 unit for cryofixation.
High-performance combined freeze-dryer and sputter coater for cryosputtering of biological samples for Electron Microscopy
Authors: Fredriksson Bengt-Arne , Bell Paul , Lindroth Margaretha 
Published: June 2020

Freeze-drying followed by sputter coating is the optimal method for preparing detergent-extracted cells for scanning electron microscopy. However, during transfer from the freeze dryer to the sputter coater, the cells are warmed to room temperature, exposed to the atmosphere, and returned to vacuum, which will cause “melting”, partial rehydration, and subsequent redrying of the sample. To avoid these potential sources of damage, we have developed an improved device that allows samples to be freeze-dried and then sputter coated while still frozen (cryosputtered) and without first exposing them to atmospheric moisture.The construction is based on a Tis-U-Dry Histological Freeze dryer, model TFD-130 (FTS Systems, Inc., Stone Ridge, NY, USA). The walls of the cylindrical vacuum chamber are cooled to -130 °C by a three-stage refrigeration system and the circular platen in the bottom of the chamber is cooled to -110 °C by conduction. The chamber is evacuated with a turbomolecular pump (Balzer model TPH 330), backed by a rotary vane pump (Balzer model DUO 016B), giving a clean, high vacuum.
A polymer designed to optimize antigen localization in immunoelectron microscopy
Authors: Olesen J.B. , Heckman C.A. , Lukinius A. 
Published: June 2020

We have developed a new polymer for the purpose of retaining the maximal antigenicity of proteins in samples embedded for electron microscopy. HACH is a mixture of hydroxyhexanedial, carbohydrazide and hydrazine that polymerizes at room temperature within 24 h. Tissues embedded in the polymer were thin sectioned and the sections, mounted on formvar films, were viewed with a Zeiss IOC transmission electron microscope. The ultrastructural features of cells in HACH-embedded tissues appeared similar to those previously found in GACH-embedded tissues.The ability to preserve the antigenicity of a protein up to the polymerization stage has been tested in the following manner. Human red blood cells, from either Rh+ or Rh- donors, were first exposed to the HACH prepolymer and then rinsed and exposed to a commercially available anti-D antibody. After removal of the prepolymer, Rh+ red blood cells were clumped by anti-D antibody to the same extent as control, untreated cells (Fig. 1).
Contrast enhancement of pollen perforations for image analysis
Authors: Vezey Edward L. 
Published: June 2020

Variation in pollen grain sculpturing constitutes one source of taxonomic evidence. With closely related species, this variation is primarily quantitative. Computerized image analysis produces accurate measurements of pollen surface features, thus making objective comparisons of quantitative sculpture variations possible. This study concerns manual methods that provide necessary contrast to features on reticulate or perforate pollen grain surfaces for image analysis. Repeatability of these methods was tested by statistically analyzing results of seven individuals. Image analysis was conducted using Kevex Feature Analysis software (Version 2.10) on a Delta class computer (Kevex Instruments, Inc., San Carlos, CA).In image analysis, features are designated by “painting” specific regions of the gray scale. A prerequisite for “painting” is sufficient contrast between features and non-features. With pollen, this requirement is often not met because: (1) surface perforations or openings (called lumina if sculpture is reticulate) sometimes contain subsurface structural elements (Fig. 1); or (2) lumina cannot be differentiated based on contrast (Fig. 2).
EDX microanalysis of cellular components in the pollen of an angiosperm, Plumbago zeylanica
Authors: Russell S. D. 
Published: June 2020

Pollen grains in flowering plants recognize compatible stigmas and transmit the sperm cells that they contain to the egg. The pollen grains bear specific proteins and lipids on their outer walls, which are the principal sources of both pollen-stigma recognition and human allergic response; they also contain the organelles required to form the pollen tube and the two sperm cells that participate in double fertilization. Although limited information is available about x-ray microanalysis of pollen grains, no information is available about the cellular distribution of elements.The contents of pollen of Plumbago zeylanica L. were burst in double-distilled water onto formvar-coated Cu slot grids ( 1 × 2 mm) and air-dried at room temperature. Grids were then examined at 40 kV in a JEOL 2000 STEM (LaB6 e' source) equipped with a high-angle 10 mm2 Kevex Quantum detector and Delta analyzer. Spectra were collected for 100-500 livetime sec; digital x-ray maps were collected at resolutions of up to 128 × 256 (dwell time: 30 msec [10-15 collections], 15-30% deadtime at ca. 1,000 cps, adjusted using the free lens control).
Application of new cryo-SEM to prove rapid freezing survival of unprotected red blood cells
Authors: Fujikawa Seizo , Ueda Shinichi 
Published: June 2020

It has been suggested that rapid freezing, by which vitrification or intracellular freezing with ice crystals less than lOnm in diameter can be achieved, may preserve not only ultrastructure but also cellular function, although the definite evidence, especially in unprotected and highly hydrated biological materials, is not yet obtained. In this study, new cryo-SEM which allows continuous observation of same frozen samples by means of cryo-SEM and then by means of freeze-replicas, was used to prove the possibility of cellular survival by rapid freezing.Human red blood cells suspended in isotonic saline were used for materials. Samples with different thickness from 25μm to 200pm were loaded on holders and frozen by slamming against LHe cooled copper block by using metal contact machine (Meiwa Co. QF-5000). The entire frozen samples were carefully removed from the holder under liquid nitrogen. Some of the frozen samples were thawed rapidly and survival (% hemolysis) were determined.
Effect of amizet solution to the hepatic failure by endotoxin-treated rat
Authors: Hirohata Yasuhisa , Kobayashi Hiroshi , Pan Je , Zheng Heng , Aihara kaoru 
Published: June 2020

Since endotoxin administration and also multiple organ failure(MOF) are accompanied by the acceleration of the proteolytic process although a sufficient energy source is given, it seems important to investigate the imbalance between consumption of branched-chain amino acids and increase of amino acid release in endotoxin treated liver. Therefore, authors have undertaken to investigate the ultrastructural alterations in endotoxin treated liver and explored the nutritional modification by branched-chain amino acid, Amizet.Male and female Sprague-Dawley rats(200-300g) were housed on a 12hrs.-light/12hrs.- dark cycle with laminar flow. Experimental Protocol: Rats were divided at random into the following four groups.Group 1: non-treated control.Group 2: A new amino acids solution riche in branched-chain amino acids, Amizet, was intraperitoneally infused at three times a week for 8 weeks.Group 3: received endotoxin(10mg/Kg, Difco Laboratories, Detroit) and observed for 8 weeks.Group 4: received endotoxin(10mg/Kg), and Amizet was intraperitoneally infused in the same procedure as Group 2 and 3.
SEM and TEM evaluation of bacterial adhesion morphology to breast prosthetic biomaterials
Authors: Fassel Theresa A. , Van Over James E. , Hauser Christopher C. , Edminston Charles E. , Sanger James R. 
Published: June 2020

Coagulase-negative Staphylococci have been implicated in late onset infection of breast prosthetic biomaterials used for augmentation and reconstruction. These prosthesis consist of either gel- or saline-filled smooth silicone rubber or textured polyurethane foam. The morphology of adhesion of staphylococci to the prosthesis is important in understanding their potential role in latent infection. Staphylococcus epidermidis rp62, a polysaccaride mucin producing strain, and Staphylococcus aureus strain 25923 are test organisms. A variety of fixative procedures employing en bloc reagents are compared in both SEM and TEM. Ruthenium red and alcian blue , uranyl acetate and ruthenium red with lysine have been used to preserve extracellular capsular/slime material in several bacterial species.Specimens of prosthetic material are incubated with cells for 18 hrs at 35°C in tryptic soy broth. For SEM, specimens are fixed in 2.5% glutaraldehyde (GA) for 2 hrs and post-fixed in 1% OsO4 for 2.5 hrs. This is followed by a graded ethanol series, critical point drying with CO2 and coating with gold/palladium.