bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bodies in the chloroplasts of sugar-beet infected by mosaic virus
Authors: A Tulegenov Tursunbai 
Published: June 2020

Beet mosaic virus (Potyvirus group ) induced two types of inclusion bodies in the chloroplasts of the cells of epidermal tissue of sugar-beet. The crystalline type of inclussions having six-edged form is the largest one and it is of the higher electron density(Pig. 1. ). The size of their edges is depended on the angle section and it is changing from 0, 33μ to 1, 5μ. The quantity of them is constant. Comparasion of large number of sections gives us the oppotunity to suppose that these inclusions in three-dimensional measuring present itselves in a form of six-edged prism, oriented along the length of the chloroplasts. Exceptions may also take place. There are met crystalls with 4-5 edges.The largest inclusion bodies copy the form of the external membrane of chloroplasts and have rounded forms or protuberant edges. (Fig. 2. ). Crystals are devided from the stroma of chloroplast with the help of single membrane (M) placing near the edges. In large magnifications in longitudinal sections of the crystals a striation(with periodicity of 7, 4 nm) is revealed. In cross sections they have lattice structure.
Ultrastructural aspects of gymnosperms reproductive organs tissues due to their functional condition
Authors: Kozubov G. M. 
Published: June 2020

The ultrastructure of reproductive organs of pine, spruce, larch and ginkgo was investigated. It was found that the male reproductive organs possess similar organization. The most considerable change in the ultrastructure of the microsporocytes occur in meiosis. Sporoderm is being laid at the late tetrad stage. The cells of the male gameto-phyte are distinguished according to the metabolic activity of the or- ganells. They are most weakly developed in the spermiogenic cell. Ta-petum of the gymnosperms is of the periplasmodic - secretorial type. The Ubisch bodies which possess similar structure in the types investigated but are specific in details in different species are produced in tapetum.Parietal and subepidermal layers are distinguished for their high metabolic activity and are capable of the autonomous photosynthesis. Female reproductive organs differ more greatly in their struture and have the most complicated structure in primitive groups. On the first stages of their formation the inner cells of nucellus are transformed into the nucellar tapetum in which the structures similar to the Ubisch bodies taking part in the formation of the sporoderm of female gametophyte have been found.
Ultrastructural morphometric investigations on human platelets
Authors: Themann H. , Stahl K. , Dame W.R. 
Published: June 2020

Qualitative fine-structure examinations of human platelets have been carried out by a number of investigators (see for example WHITE (1972) and references in his report). It is the purpose of this report to characterize the normal values of morphometric variables occurring in human platelets.Materials and MethodsPlatelets were obtained from clinically healthy females with ages ranging from 18-32, all of whom had documented normal hematological findings (normal differential, platelet count, PT, PTT, and fibrinogen values) and no history of drug use for at least 2 months. All blood samples (one per donor) were obtained by large-bore (1.5 mm) needle puncture of the medial antecubital vein. Samples were treated in one of the following two ways:(1)after disposal of the first ml, 9 ml were slowly drawn into a syringe containing 1 ml of 3.8% sodium citrate. Samples were then immediately centrifuged at 1000 x g for 1.5 min at 23°C.
Membranes and cytoskeleton in human platelets during webbing
Authors: Inczédy-Marcsek M. , Lindner E. 
Published: June 2020

The intracellular membranes of blood platelets, dense tubular system (ER) and Golgi apparatus (GA), play a major role in platelet function. Their arrangement within spreading platelets as a model system is demonstrated by a modified osmium-ferro-cyanide postfixation method.Venous blood was either dropped into the fixative, or citrated platelet rich plasma was dropped on carbon coated gold grids or plastic discs and incubated for 5 - 60 min in a moist chamber, 20° C.Glutaraldehyde (GA) 0, 2-3, 5% or paraformaldehyde 4% in 0, 1 M-0, 15 M cacodylate buffer, pH 7, 4 (CACO) with or without glucose-dextran or 5 mM CaCl2 added.1. 1% OsO4 in 0, 15 M CACO, 60 min, followed by 2% uranylacetate in H2O or 15% acetone, 10-60 min (Os-UA), 2. 0, 8% ferrocyanide in 2% OsO4 in 0, 12 M CACO, 2 hrs (Os-Fe).
Histochemical and autoradiographic findings on specific granules of the endothelial cells
Authors: Fujimoto Sunao , Yamamoto Koji , Takeshige Yoshio 
Published: June 2020

Since the first description of specific granules of endothelial cells, similar electron dense granules have been described in various vessels. However, their chemical nature and function are still uncertain; the possibilities that they may be lysosomal bodies or peroxisomes have been completely denied by previous experiments.A remarkable increase in number of endothelial specific granules was observed in the postnatal rabbit umbilical veins. The granules are very few in number in the prenatal vessels but many immatured forms of the granules have appeared near Golgi apparatus in the late fetal condition. The increase is the most pronounced between 2 and 10 days after birth, especially in the endothelial cells where the vascular lumen is obliterating (Fig. 1). The granules gradually decrease in number after 20 days and have almost disappeared at 30 days. The release of their content from the cell surface into the vascular lumen by exocytosis is supposed by our micrographs. Such transient increase at a particular condition of the vessels strongly suggests that these granules may have some function for the vascular obliteration.
Pulmonary neuro-epithelial bodies—ultrastructure, surface morphology and effects of pharmaca in vitro
Authors: Cutz E. , Sonstegard K. S. , Chan W. 
Published: June 2020

Recently, intraepithelial innervated corpuscles, referred to as neuro-epithelial bodies (NEB) have been identified within the airway mucosa of human and animal lungs. The specialized cells of NEB share certain features of APUD (Amine Precursor Uptake and Decarboxylation) endocrine cells, such as argyrophilia, amine contents and presence of cytoplasmic dense core vesicles (DCV). Although the precise function of NEB in lung remains still unknown, it has been suggested that NEB may represent intrapulmonary receptors or alternatively may have an endocrine function.In this study, NEB in lungs of near-term rabbit fetuses (29 days gestation) were examined by transmission (TEM) and scanning electron microscopy (SEM), prior to and following short term organ culture. The ultrastructure and surface morphology of NEB in control animals was compared with a) NEB in rabbit fetal lung explants maintained in vitro for 7-10 days; b) lung explants incubated with reserpine, (an amine releasing agent) or Ca++ ionophore A-23186 (compound used for studies of calcium mediated secretion).
Morphological modifications of alveolar type II pneumocytes following cycloheximide treatment
Authors: Collet A. J. 
Published: June 2020

Chemical, histochemical and radioautographic studies of surfactant have demonstrated that it is composed mainly of phospholipid (phosphatidylcholine) and of protein and polysaccharide material and that its production is closely related to type II pneumocyte (PNM). The question whether the components of surfactant are independently synthetized or are chemically bounded has not received a clear answer. Metabolic active substances have been used in vivo to observe the effects of protein inhibitors on the lamellar bodies formation and on the morphology of the type II PNM. In a previous study, puromycin has been used and a strong decrease of the lamellar bodies was observed; this decrease was dependent of the time interval after the administration, 125 and 155 min. respectively (Collet & Chevalier, 1974, 1977).In the present study, cycloheximide, an other protein synthesis inhibitor, was utilized, which is known to act following a mechanism different of that of puromycin.
Inner surface ultrastructure of the lungs of frog and lizard
Authors: Bils R. F. , Hughes G. M. 
Published: June 2020

Mammalian lung cells and tissues have been studied extensively, resulting in a voluminous literature. In comparison, the ultrastructure study of the respiratory systems of the lower vertebrates is incomplete. Lung surfactant and the related osmiophilic lamellar inclusions were observed in bird lung by Lambson and Cohn and in cultured frog lung cells by Soloff and Burns. This report compares the inner surface structure, cell types and vascularization in the lungs of frog and lizard.Mature Rana pipiens and Lacerta viviparus lungs were fixed at normal volumes (approximately 0. 3 ml and 0. 05 ml, respectively) with cacodylate-buffered glutaraldehyde, post-fixed with OsO4 and processed for both TEM and SEM.Frog LungLooking outward from the central duct, the septa divide the respiratory regions into smaller and smaller compartments, ending in closed sacs or alveoli, ranging from 150 to 300 mμ in diameter (Fig. 1). The largest or primary septa are covered by ciliated epithelium, whereas a squamous microvillous epithelium covers the minor septa and alveolar walls (Fig. 2). In section, the microvillous epithelial cells appear as a combination of type 1 and type 2 alveolar epithelial cells of the mammalian lung. Capillaries appeared as a random network through the septa and alveolar walls.
An ultrastructural study of the alveo-capillary block of the lung induced by E. Coli endotoxin—a correlative cytochemical and biophysical study
Authors: Yokoi Kimiyoshi , Sasamoto Yoshinobu , Shirota Deog Young KIM Akiro , Aihara Kaoru , Yajima Gompachi 
Published: June 2020

The Endotoxin(E. Coli 0-26) has been regarded as the most frequent and outstanding causative factor of the shock in the lung. More importantly the substance is acting as the casuative factor of the clinically observed disseminated intra-vascular coagulopathy. In this connection the substance may play a very important roll in causing the alveo-capillary block. A rather extensive survey of the biophysical, morphological investigation has been undertaken and the present communication is dealt with the rather earlier changes of the blood-air barrierr which eventually leads to the alveo-capillary block. Incidentally a correlative study with the alteration of the alveolar lining layer which may possess the interface action(Pulmonary surfactant) and qualitative determination of the interface action.The adult rats of both sexes served as materials. They recieved repeated injections of E. Coli endotoxin 0-26, l00mg/kg. and sacrified by decapituation chronologically.
Immuno and histochemical electron microscopic studies of the selective permeability, involving the feto-maternal junctional barrier
Authors: Hata Toshio , Ohkawa Kimiyasu 
Published: June 2020

Regarding to the cellular transfer and absorption mechanism of the trophoblast in the feto-maternal junctional zone, it is awaited futher confirmation in the future. Numerous documentation has been accumulated on this aspect, utilizing the visible markers such as the fat(Yamaguchi), ferritin(Tillack) and IgG(Morphis). however, the observations are mainly based on the investigations of the placenta in vitro. From this view point, the authors have made a rather comprehensive observation of the cellular transfer and absorption mechanism of the human feto-maternal junction in physiological circumstance.Materials and methods: The specimens of the human uterus in early ges tation are removed surgically for therapeutic purpose had served as materials. The chorionic tissue and implanted tissue from the uterus were carefully investigated. The method of the investigation are as follows: 1) Conventional transmission electron microscopic observation with double electron stains. 2) Visualization of the iron dextran(Fesin), it is usually used to iron deficiency anemia, which was administered prior to the surgical removal of the uterus.
Paracrystalline structures in the oocytes of a mouse, mus cervicolor poppaeus
Authors: Szöllösi Daniel , Claussen Claus-Peter 
Published: June 2020

Large and multiple paracrystalline bodies exist in the cytoplasm of the oocytes of a wild mouse strain originating in Thailand, Mus cervicolor poppaeus. The structural details of these crystals are identical to much smaller paracrystalline structures described in preimplantation embryos of the laboratory mouse, Mus musculus (Enders and Schlafke, 1965; Calarco and Brown, 1969; Calarco and Szöllösi, 1973). These latter often occur in close proximity or even in contact with the rough endoplasmic reticulum (RER). A number of A-type virus like particles bud into these cirternae. In spite of the fact that thus far no intracisternal A-type particles were recognized in oocytes of Mus cervicolor poppaeus the similarity between the two paracrystalline structures warrants their description and comparison.In the cytoplasm of oocytes we collected by puncture from large Graafian follicles of Mus cervicolor poppaeus. In one micron sections stained with Richardson´s strain (Richardson et al., 1960), rhomboidal crystalline bodies of various sizes can be recognized. The crystalloids stain intensely blue (Fig. 1).
Ultrastructure of the decidual cells of the basal plate of the human placenta at term
Authors: OliVar C. , Castejon S. 
Published: June 2020

To understand the role of the decidual cells of the basal plate of the human placenta at term in the passage of the antigens and antibodies, in the production of hormones, in the nutrition of the embryo and its possible function in the formation of fibrilar proteins, a systematic study of their ultrastructure has been necessary.Immediately following a spontaneous delivery, samples of the decidua were taken and fixed by immersion in 2% g1utara1dehyde in phosphate buffer 0. 2 M (PH 7. 4). The specimens were washed in a similar buffer for 1 hour and postfixed in 2% osmic acid in phosphate buffer 0. 2 for 3 hours at 4°C. After dehydrating the samples in a graded series of ethanols and propylene oxide they were embedded in Araldite. Ultrathin sections were then stained with uranyl acetate and lead tricitrate and examined under the electron microscope. The submicroscopic observations show that: The plasmamembrane of these cells demonstrates numerous irregular, globulous or polyhedral extensions (Fig. 1a), which intermix with the intercellular substance or connect with adjacent cells by means of desmosomes (Fig. 1b). The hyaloplasmic matrix (Fig. 2) is of low electron density, homogenous, with numerous free ribosomes and cytoplasmic microfilaments (Fig. 4) which are arranged in bundles dispersed throughout the cytoplasm in different directions.
Sperm binding and formation of the fertilization envelope by surface complexes isolated from sea urchin eggs
Authors: Decker Glenn L. 
Published: June 2020

During fertilization of the echinoderm egg the sperm cell undergoes the acrosomal reaction and binds species-specifically to the vitelline layer, which is attached to the exterior surface of the egg plasma membrane. Following initial interaction and fusion of the limiting membranes of the egg and the sperm, the cortical vesicles attached to the inner surface of the egg plasma membrane (Fig. 1) fuse and secrete components which appear to modify the vitelline layer, giving rise to the fertilization envelope.Recently, the surface and associated secretory vesicles of the egg were isolated from homogenates by differential centrifugation in sea water containing 25 mM EGTA (Fig. 2) (2). Determination of the extent to which this cell surface-secretory complex can be induced to mimic fertilization related events observed with intact eggs is currently in progress.
Some observations of the morphology of the glial and neuronal cell populations in monolayer culture
Authors: Wong Y. C. , Garber B. B. 
Published: June 2020

Attempts have been made in the past to separate the glial and neuronal populations of cells for various studies. The homogeneity of cell populations achieved using these methods remains to be improved. Using a modified separation method and combined with subculturing, very pure glialand neuronal populations have been obtained. This paper reports the surface features and some properties of the two cell populations using the modified culture method.Ten day old chick embryo cerebra were removed aseptically and the meninges carefully excised. The tissues were washed in calcium and magnesium free (CMF) tyrode solution before incubation for 35 min. at 37°C in 0. 2% of trypsin in CMF. The cells were dissociated in E-II medium by gentle flushing of the tissues with a fine bore pipette for about 20 times. To each of the 35 mm culture dishes containing 2 ml of E-II medium and a poly-L-lysine coated coverslip, one ml of cerebral cell suspension was added and the cells were allowed to plate on a coverslip for 7 minutes at room temperature.
Quantitation of calcium in native myocardial and fractioned sarco-plasmic reticulum by electron probe X-ray microanalysis
Authors: Wendt-Gallitelli M. F. , Schlote W. , Wolburg H. , Schwegler M. 
Published: June 2020

The importance of the sarcoplasmic reticulum in the regulation of myocardial contraction is today still unclear. X-ray microanalysis of elements in the cell compartments involved in excitation-contraction coupling can contribute to the understanding of this question if the following prerequisites are met: treatment of the tissue should not alter the distribution of diffusible ions, and the method of detection should be sufficiently sensitive.In order to test whether electron probe microanalysis is suitable for myocardial Ca in sarcoplasmic reticulum, ultrathin cryosections were taken from native myocardial tissue and from isolated sarcoplasmic reticulum of the cat. This fragmented sarcoplasmic reticulum (FSR) was chosen for two reasons: first, if the x-ray microanalysis of isolated active SR vesicles maximally loaded with Ca did not show Ca, further experiments on myocardial tissue using this method would have been useless. Second, if Ca identification is possible using this method, the isolated FSR can be utilized as a standard for quantitation of Ca in native tissue since the amount of Ca taken up in the FSR is known before the analysis and can be arbitrarily varied.
SLS crystallites and reconstituted fibrils made from locust collagen
Authors: Ashhurst Doreen E. 
Published: June 2020

That insects possess collagen fibrils similar to those of vertebrates is well established. In some insects, the fibrils are very thin and indistinctly banded, while in others, for example, locusts and cockroaches, fibrils of larger diameter and distinct banding are found. Estimates of the periodicity of the banding of sectioned fibrils range from 56nm to 63nm (see 2), but the interband patterns are similar; the variation in the periodicity is probably due to the preparative procedures. A peculiarity of many of the fibrils is that on ageing they become very large and irregular in cross-section; typical examples are found in the connective tissue around the ejaculatory duct of 2-3 week old adult male locusts, Locusta migratoria. Similar large, irregular fibrils are found in some pathological conditions in mammals. One way to establish similarities between collagens is to compare their segment-long-spacing (SLS) crystallites and reconstituted fibrils, and so these experiments were performed with locust collagen.Locust collagen is not readily soluble in salt or dilute acids, and so to increase its solubility, newly-moulted, adult male locusts were fed on wheat seedlings sprayed with a 1% solution of β-aminoproprionitrile, a lathrytic agent which reduces cross-linking in mammalian collagens.
Artifacts on the surface of articular cartilage due to drying methods
Authors: Hesse I. , Hesse W. 
Published: June 2020

Since the advent of scanning electron microscopy very contrasting studies on the surface topography of normal and pathological cartilage have been published. The existing literature did not respect the influence of tissue preparation, especially the effect of the drying techniques. Thus the results lead to wrong conclusions. The purpose of this paper is to compare the preservation of the surface morphology obtained from three drying techniques, i. e. air-, freeze- and critical-point drying.Our experiments were performed on normal articular cartilage of 50 sheep, on transplanted cartilage of 45 sheep and on articular cartilage taken intraoperatively from 33 patients. Three adequate samples of articular cartilage attached to bone were dissected out of the weightbearing portion of the medial femoral condyle for air-, freeze- and critical-point drying. They were rinsed in 4 changes of cacodylate buffer (pH=7. 2-7. 4).
Ultrastructural identification of Toxoplasma gondii in the acquired immunodeficiency syndrome
Authors: Price George , Pearl Gary , Cerezo Lizardo 
Published: June 2020

With the onset of the Acquired Immunodeficiency Syndrome (AIDS), a variety of opportunistic infections have now become prevalent as a complication of the Human Immunodeficiency Virus (HIV). These infections may be viral, bacterial, fungal, or protozoal.Toxoplasma gondii is a protozoan that can infect humans in parasitic symbiosis. In the past, toxoplasmosis was most commonly found as a congenital infection of neonates, but has become a prominent infection of patients with AIDS. The cystic stage of the organism may be found in the central nervous system, skeletal muscle, cardiac muscle, and visceral organs. The tachyzoites, or individual organisms, are found in a variety of tissues, cells, and body fluids. The route of infection is either by ingestion of the organism from material contaminated by feline feces, or from the ingestion of the coccidian oocysts from the meat of infected animals.
Eukaryotic genome organization analyzed by electron microscope in situ hybridization
Authors: Hamkalo Barbara A. , Narayanswami Sandya , Dvorkin Nadja 
Published: June 2020

In situ hybridization is a powerful tool for the localization of DNA/RNA sequences in nuclei and chromosomes. The introduction of nonisotopic labelling methodologies in conjunction with fluorescent or enzyme-linked detection have resulted in a dramatic increase in the application of this technique at the light microscope (LM) level and has placed it in a pivotal role in cell biology, development and genetics. Development of equivalent mapping protocols at the EM level offers increased spatial resolution. We have combined the use of nonisotopic probes with invmunogold labelling to investigate eukaryotic genome organization at high resolution.Metaphase chromosomes released from mitotically-arrested cells are deposited on gold EM grids by centrifugation through a sucrose cushion. After fixation (0.1% glutaraldehyde, 20 min) and DNA denaturation, chromosomes are hybridized to cloned probes enzymatically labelled with biotin-dUTP, digoxigenin-dUTP, dinitrophenyl-dUTP or covalently coupled to N-acetoxyacetoaminofluorene. Hybrid sites typically are detected by a two-step antibody incubation and 1-30 nm colloidal gold particles.