bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ultrastructural morphology and allergen detection in birch pollen after aqueous, anhydrous‐liquid, and vapor fixation techniques
Authors: Grote Monika 
Published: February 2005

AbstractIn order to find a good compromise between preservation of ultrastructural morphology and retention of antigenicity, birch pollen grains were chemically fixed in aqueous p‐formaldehyde or glutaraldehyde, in p‐formaldehyde or glutaraldehyde dissolved in anhydrous glycerol, and in p‐formaldehyde or glutaraldehyde vapor. Representative cytoplasmic areas were inspected for the preservation of ultrastructural morphology and for their capacity to bind a monoclonal antibody against Bet v I, the major birch pollen allergen. The experiments showed that cytoplasmic morphology was best preserved after vapor fixation in p‐formaldehyde. This fixation also led to the highest degree of specific antibody binding. © 1992 Wiley‐Liss, Inc.
Comparison of nuclear hydration in boar spermatozoa before and after freeze‐thawing: Contrast analysis of cells embedded in bromide‐labeled medium
Authors: Courtens J. L. , Ekwall H. , Plöen L. 
Published: February 2005

AbstractEpon labeled with bromide was used to embed ejaculated and freeze‐thawed spermatozoa, with the hypothesis that it replaces most of cell water. Image analysis of relative contrasts between sperm nuclei and the surrounding medium revealed that when used in low concentrations, bromide is mostly absorbed to the nuclear structures. For higher concentrations, the chromatin is saturated, and the increase in contrast can be used to calculate relative differences in the hydration of nuclei. Boar sperm nuclei are more hydrated after freeze‐thawing than before. © 1992 Wiley‐Liss, Inc.
An image processing/stereological analysis system for transmission electron microscopy
Authors: Poole Max C. 
Published: February 2005

AbstractThis study examines the feasibility of combining computer image digitization, image enhancement, and point counting stereological techniques to quantify video images from transmission electron microscopes (TEM). The essential hardware consists of an IBM PC/AT, a Matrox imaging board, a digitizing tablet, a high resolution black and white monitor, and a portable mass storage device. In addition a video camera must be mounted to the TEM. The software is written in three modules which have numerous routines for image acquisition, enhancement, and quantification. Quantification is achieved by selecting an electronic lattice and superimposing it on the cell image. A cursor is moved on the lattice (via the digitizing tablet) and the points are entered into a spreadsheet. One of the major limitations of the system was the reduced resolution inherent in the current hardware. However, sampling experiments showed that one could compensate for the reduced resolution by increasing the magnification of the digitized images, and the stereological values from digitized images compared favorably to those from electron micrographs. Furthermore, the system proved advantageous by eliminating the usual darkroom work, and in enhancing low contrast tissue. In spite of several hardware limitations, the concept of quantifying computer digitized TEM images appears promising. © 1992 Wiley‐Liss, Inc.
Morphometric evaluation of populations of neuronal profiles (cell bodies, dendrites, and nerve terminals) in the central nervous system
Authors: Zoli Michele , Guidolin Diego , Agnati Luigi F. 
Published: February 2005

AbstractMorphometric techniques have been developed to quantitatively characterize groups of transmitter‐identified neuronal profiles, such as cell groups, dendrite and nerve terminal fields. These morphometric techniques will be illustrated by introducing some general tools for image analysis which can be considered as a background for the present specific applications. The following methods have been included: (1) methods to identify and quantitatively characterize, from both numerical and geometrical standpoints, groups of profiles in a two‐ and three‐dimen‐sional frame; (2) methods to evaluate the evenness of a certain distribution of profiles in the plane; (3) methods to identify subgroups of profiles based on their different spatial or optical density; and (4) methods to compare the distributions of two or more groups of profiles. The applications of these general tools to some neuroanatomical problems, such as cell group definition and description, have been illustrated. Practical examples performed on immunocytochemical preparations of neuronal profile populations are also given. Finally, the potentiality of numerical classification to classify and compare morphometric data has been shown. As an example, numerical classification methods have been applied to the morphometric and microdensitometric analysis of adrenaline/neuropeptide Y costoring neuronal systems of the brainstem in adult and aged rats. © 1992 Wiley‐Liss, Inc.
A new procedure for handling impervious biological specimens
Authors: Lindley V. A. 
Published: February 2005

AbstractA new application of techniques for preparing impervious biological specimens for light microscopy (LM) and transmission electron microscopy (TEM) has been developed. Microwave irradiation was used to facilitate fixation. A priming technique was used to increase the bonding of the outer surface of the specimens with the resin. Priming the waxy or cuticular surface with Z‐6040 (gamma‐glycidoxypropyl trimethoxysilane) solved the problem of specimen “pull out” from the resin. Insect specimens with various types of cuticles (waxy or chitinous) and seeds were successfully studied ultrastructurally using this technique. © 1992 Wiley‐Liss, Inc.
Fine structure of olfactory epithelia of gastropod molluscs
Authors: Emery Dennis G. 
Published: February 2005

AbstractAmong gastropod molluscs the chemical senses are most important for location of distant objects. They are used in food finding, locating mates, avoiding predators, trail following, and homing. Chemoreceptors are commonly associated with the oral area, the tentacles, and the osphradium, which lies in the mantle cavity.Most chemosensory neurons are primary sensory neurons, although secondary sensory cells have been reported in the osphradium of some prosobranch gastropods. Most chemosensory organs contain sensory cells with ciliated sensory endings that are in contact with the external environment. Some sensory endings have only microvilli or have no surface elaborations. Cilia on sensory endings are commonly of the conventional type, but some species have modified cilia; some lack rootlets, some have an abnormal microtubular content, and some have paddle‐shaped endings. The perikarya of sensory neurons may be within the sensory epithelium, below it, or in ganglia near the sensory surface. In some groups of gastropods there are peripheral ganglia in the olfactory pathway; in others chemosensory axons appear to pass directly to the CNS.Olfactory epithelia of terrestrial pulmonates have modified brush borders with long branching plasmatic processes and a spongy layer of cytoplasmic tubules which extend from the epithelial cells. Sensory endings of the olfactory receptors are entirely within this spongy layer. Aquatic pulmonates may have a similar spongy layer in their olfactory epithelia, but the cilia of sensory endings, as well as motile cilia of epithelial cells, extend well beyond the spongy layer. © 1992 Wiley‐Liss, Inc.
Ultrastructural histopathology of human olfactory dysfunction
Authors: Moran David T. , Jafek Bruce W. , Eller Pamela M. , Rowley J. Carter 
Published: February 2005

AbstractThis paper presents electron‐microscopic observations on biopsies of the olfactory mucosae of several classes of patients with smell disorders: 1) patients with loss of smell function following head injury (post‐traumatic anosmics or hyposmics); 2) patients with loss of smell function following severe head colds and/or sinus infections (post‐viral olfactory dysfunction, or PVOD); and 3) patients that have lacked smell function since birth (congenital anosmics). Of these, the traumatic anosmics' olfactory epithelia were quite disorganized; the orderly arrangement of supporting cells, ciliated olfactory receptor neurons, microvillar cells, and basal cells was disrupted. Although many somata of ciliated olfactory receptors were present, few of their dendrites reached the epithelial surface. The few olfactory vesicles present usually lacked olfactory cilia. The postviral anosmics, too, had a greatly reduced number of intact ciliated olfactory receptor neurons, and most of those present were aciliate. The post‐viral hyposmics had a larger population of intact, ciliated olfactory receptor cells. In the seven cases of congenital anosmia studied, no biopsies of olfactory epithelium were obtained, indicating the olfactory epithelium is either absent—or greatly reduced in area—in these individuals. © 1992 Wiley‐Liss, Inc.
Immunocytochemical localization of cell adhesion molecules in the developing and mature olfactory system
Authors: Miragall Fernando , Dermietzel Rolf 
Published: February 2005

AbstractThe localization of Ca++‐independent cell adhesion molecules (CAMS) in the developing and mature olfactory epithelium and bulb is reviewed. The CAMs included in this article are the neural cell adhesion molecule (N‐CAM), the 180 kD component of N‐CAM (N‐CAM 180), the embryonic form of N‐CAM (E‐N‐CAM), L1 glycoproteins, J1 glycoproteins, and the adhesion molecule on glia (AMOG). In addition, the expression of the L2‐HNK‐1 carbohydrate epitope, shared by N‐CAM, L1, J1 and myelin‐associated glycoprotein (MAG) in the adult olfactory epithelium and bulb has also been documented. For the localization of these molecules at the light and electron microscopic levels, immunocytochemical techniques were used and are described in detail.During development and organogenesis, the olfactory system exhibits a pattern of CAM expression similar to the general pattern described for the developing nervous system. In the adult olfactory system, however, a significant retention of CAMs characteristic for developmental and morphogenetic processes, such as E‐N‐CAM, AMOG, as well as the high molecular weight components of J1 glycoproteins, can be observed. The retention of these embryonic features are most likely associated with the cell turnover and high plasticity of this system. Moreover, the predominance of N‐CAM 180 with respect to other components of N‐CAM, as well as the absence of the L2/HNK‐1 carbohydrate epitope, are also particular traits of the primary olfactory system which could be associated with its exceptional properties. © 1992 Wiley‐Liss, Inc.
Comparison of bromine and permanganate as ultrastructural stains for lignin in plants infected by the fungus Colletotrichum lagenarium
Authors: Stein Barry D. , Klomparens Karen L. , Hammerschmidt Raymond 
Published: February 2005

AbstractTransmission electron microscopy (TEM) and energy dispersive X‐ray microanalysis (EDS) were used to localize manganese from KMnO4, and bromine, as ultrastructural stains for lignin in an herbaceous plant. The Spookie cultivar of pumpkin is susceptible to infection by the fungus Colletotrichum lagenarium and served as a model system to compare the Br and KMnO4 techniques. Bromine was used in a fixation/staining procedure, and in separate experiments, KMnO4 was used as either a fixative or as a postsection stain. The technique for using bromine was modified from the woody plant procedure by adding a paraformaldehyde prefixation step. With the bromine procedure, cell walls were well‐preserved, but the cytoplasm was heavily extracted. The KMnO4 procedures produced well‐fixed cytoplasm, but with some staining artifacts. With all procedures, EDS dot mapping demonstrated lignin deposition in the cell walls specifically associated with sites of fungal infection. Lignin was also localized in secondary walls of tracheary elements, sites known to be highly lignified. The bromine procedure provided the most specific localization of lignin with a minimum of artifact. The specific applications of these stains provided data on the ultrastructural localization of lignin which contributed to the elucidation of its role in the interactions between pathogenic fungi in both their resistant and susceptible plant hosts. © 1992 Wiley‐Liss, Inc.
A technique for exposure of the glycoproteic matrix (zona pellucida and mucus) for scanning electron microscopy
Authors: Familiari G. , Nottola S. A. , Macchiarelli G. , Familiari A. , Motta P. M. 
Published: February 2005

AbstractThe fine structure of the zona pellucida (ZP) covering the oocyte and of the mucus covering the surface of the intestinal villi was investigated by using a new method employing ruthenium red (RR), saponin, and osmium‐thiocarbohydrazide impregnation.The glycoproteic matrices both appeared constituted by thin filaments (ranging from 22 to 50 nm in thickness) anastomosed to form a very fine network.RR prevented the dissolution and/or alteration of glycoproteins and polyanionic carbohydrates induced by acqueous fixatives. Saponin was a detergent of the soluble proteins. Osmium‐thiocarbohydrazide preserved the glycoproteic matrix filaments from the mechanical stress induced by dehydration and critical point drying and reduced filaments packing and shrinkage. The technical improvement was demonstrated by the following results: 1) a regular arrangement of the filaments network; 2) a thickness of mucus filaments smaller than that obtained with other methods of preparation; 3) a homogeneous thickness of ZP filaments.This method allowed a very detailed study of the fine structural organization of the ZP and intestinal mucus. Therefore, this technique can be useful for a better evaluation of the morphodynamic of these and other glycoproteic matrices. © 1992 Wiley‐Liss, Inc.
Electron microscopy of in vivo recorded and intracellularly injected inferior olivary neurons and their GABAergic innervation in the cat
Authors: Ruigrok Tom J. H. , De Zeeuw Chris I. 
Published: February 2005

AbstractThis paper reports on the detailed morphology of inferior olivary neurons in the cat following electrophysiological examination, intracellular injection with horseradish peroxidase, and gamma aminobutyric acid (GABA) immunocytochemistry.The activity of olivary cells was recorded intracellularly in vivo and their response to mesodiencephalic stimulation was tested. In a number of cases their response to stimulation of the contralateral superior cerebellar peduncle was also tested. Mesodiencephalic stimulation resulted in monosynaptic, and superior peduncle stimulation in disynaptic activation of cells in the medial accessory and principal olivary subdivisions. Rebound olivary activity was usually only found after mesodiencephalic stimulation.Light microscopic investigation of osmicated and Araldite embedded Vibratome sections was facilitated considerably when performing the osmication in a glucose solution. Peroxidase labeled olivary cells, like that earlier described for Golgi‐impregnated material, possess a complex globular dendritic geometry. Especially, and unlike Golgi material, the abundance of exceptionally long and complex spiny appendages could be appreciated. The axons usually stemmed from first order dendrites and did not give rise to recurrent axon collaterals.The ultrastructural analysis of this material, mainly from serial sections, was combined with postembedding GABA immunohistochemistry. In this way, GABAergic as well as non‐GABAergic profiles were studied in conjunction with HRP labeled cellular elements.The GABAergic terminals usually contained pleomorphic vesicles and made symmetrical synapses whereas non‐GABAergic terminals nearly always formed asymmetrical synapses and contained round or oval vesicles. Most, if not all, HRP labeled spiny appendages were incorporated in glomeruli. A particular spiny appendage may contribute more than one spine head to a glomerular core, which, on average, consisted of spiny elements of six different neurons. A glomerular core is surrounded by approximately the same amounts of GABAergic and non‐GABAergic boutons. Also, all spiny appendages, and most of their individual spine heads, are contacted by GABAergic as well as non‐GABAergic boutons. Spiny appendages on the axon hillock may be incorporated in dendritic glomeruli, however, most synapses with the hillock were made by GABAergic boutons.The combined physiological and morphological observations imply that (1) the cerebellar nucleican excert an excitatory influence on inferior olivary neurons through a mesodiencephalic relay, (2) the GABAergic nucleo‐olivary input seems to be capable of diminishing the oscillatory tendencies of olivary neurons, and (3) the mesodiencephalic (non‐GABAergic) and cerebellar (GABAergic) input may subserve a timing function since these inputs systematically impinge upon the same olivary spines. © 1993 Wiley‐Liss, Inc.
Glial cells in the nerve fiber layer of the main olfactory bulb of embryonic and adult mammals
Authors: Doucette R. 
Published: February 2005

AbstractThis article provides a detailed description of the glial cell types in the nerve fiber layer of the main olfactory bulb during embryonic development, in adult mammals, and at the nerve entry zone of the first cranial nerve. In adult mammals, the glial cell types of the olfactory nerve fiber layer include intrafascicular ensheathing cells, which have the exclusive role of ensheathing the olfactory axons in both the PNS and CNS, and interfascicular astrocytes, which occupy the spaces between adjacent olfactory fascicles. The ensheathing cells are particularly interesting because they possess a mixture of Schwann cell and astrocytic phenotypic features, are more likely to be of placodal than of CNS origin, and have the exclusive role of forming the glia limitans at the PNS‐CNS transitional zone. It is proposed that one important function of ensheathing cells is to modulate the growth of olfactory axons within the CNS; this modulation is probably mediated by selective cell adhesion molecules, extracellular matrix molecules, and chemotropic agents. © 1993 Wiley‐Liss, Inc.
Functional organization of the main olfactory bulb
Authors: Scott John W. , Wellis David P. , Riggott Marcia J. , Buonviso Nathalie 
Published: February 2005

AbstractComplete understanding of the role of the mammalian main olfactory bulb in sensory processing has remained elusive despite many detailed studies on its anatomy and physiology. Several lines of recent evidence viewed in the context of earlier knowledge have provided new insights into the bulbar mechanisms of olfactory coding. The output cells of the olfactory bulb receive a localized olfactory nerve input and interneuronal input via dendrodendritic synapses on distinct sets of dendrites. The spatial arrangement of granule cell contacts on output cell basal dendrites suggests that lateral inhibitory interactions may occur between neighboring output cells. The input from olfactory receptor cell axons to the bulb also has spatial order, but does not represent a precise map of the receptor surface. Recent studies with antibodies and lectins suggest that different groups of axons from chemically similar receptor cells collect into certain glomeruli, even if the axons originate from cells that are not contiguous in the mucosa. Electrophysiological studies have begun to explore the participation of spatially organized circuits in olfactory processing. The degree to which neighboring output cells respond similarly to odor stimulation, for example, depends on the distance between the cells, with those further apart showing complementary responses. Also, a single output cell can show 2 or more different temporal response patterns when different odors are presented. Intracellular recordings indicate that these responses are shaped by IPSPs. Electrical stimulation during such recordings shows that some mitral cells are excited by nerve inputs close to their glomerular tufts, while they are inhibited by nerve inputs to other parts of the bulb. Finally, recordings from granule and periglomerular cells indicate their potential in mediating components of output cell odor responses. These considerations suggest that the olfactory bulb performs a spatially based analysis on the information coming from the receptor cells. While the spatial organization of the olfactory bulb is probably not faithfully represented in the projections to the olfactory cortex, bulbocortical projections are not random. The fact that spatial factors exist at each of these levels in the olfactory system must be considered in developing models of central olfactory processing. © 1993 Wiley‐Liss, Inc.
Are there structural and functional modules in the vertebrate olfactory bulb?
Authors: Kauer John S. , Cinelli Angel R. 
Published: February 2005

AbstractA number of different recording methods have shown that odorants elicit patterns of neuronal activity widely distributed across cells of the olfactory receptor epithelium, olfactory bulb, and piriform cortex in the vertebrate olfactory system. These findings suggest that the physicochemical properties of odorant molecules are processed by distributed coding mechanisms activated in parallel in olfactory circuits in order to characterize a single, “monomolecular” odorant. These findings also suggest that the response patterns seen at higher levels are set up by differential responses in peripheral receptor cells of the olfactory epithelium. One requirement for understanding the details of this proposed encoding scheme is correlation of odor‐generated patterns with the components of these circuits. In this paper, results from 2‐deoxyglucose and voltage‐sensitive dye studies suggest that certain components of these responses may relate to patterns established in reproducibly identifiable aggregates of bulbar cells. These findings are consistent with previous observations suggesting that columnar groups of periglomerular, mitral/tufted and granule cells, oriented perpendicular to the laminae of the bulb, are functionally related to one another. Such cell groups or modules, when activated in parallel, could serve as building block components of the complete ensemble response. According to this hypothesis, different sets of such modules would be activated with different odorant stimuli and modules could be shared to the degree to which the physicochemical properties of the different stimuli overlap. © 1993 Wiley‐Liss, Inc.
Contrast enhancement and polymer identification in the electron microscope by the formation and staining of unsaturated double bonds
Authors: Parker M. A. , Vesely D. 
Published: February 2005

AbstractA new technique for the identification of phases contained within a polymer blend is described in this paper. The technique utilises the beam damage which occurs when polymers are irradiated in an electron microscope. It has been found that during the irradiation process isolated double bonds are formed which can be revealed by staining with osmium tetroxide. The density of staining and its relationship to electron exposure is shown to be a characteristic feature of a particular chemical structure. It allows for polymer phase identification with a high spatial resolution and also for contrast enhancement and preservation. This technique offers a unique way of studying a fine dispersion of phases in polymer blends, even where only low atomic number elements such as C, H, and O are present. © 1993 Wiley‐Liss, Inc.