bluuebunny/crossref_metadata_2025_split huggingface dataset:
Plasticity of postganglionic sympathetic neurons in the rat superior cervical ganglion after axotomy
Authors: Klimaschewski Lars , Tran Thang D. , Nobiling Rainer , Heym Christine 
Published: February 2005

AbstractThe neuropeptides galanin (GAL) and vasoactive intestinal polypeptide (VIP) are upregulated in spinal and vagal sensory as well as in cranial motor neurons after axonal transection. In this study an increase of both peptides is demonstrated in axotomized principal ganglionic neurons (PGN) of the rat sympathetic superior cervical ganglion by use of double‐labeling immunofluorescence. Compared to control ganglia that do not contain more than 1% GAL‐ or VIP‐positive cells, about 26% of all PGN exhibit GAL immunoreactivity by day 1 after transection of the major postganglionic branches. The proportion of immunoreactive neurons reaches its maximum after 30 days (40%) and decreases to about 27% within the second month after axotomy. The percentage of VIP‐positive neurons is much lower than for GAL: 2% of the PGN exhibit VIP immunoreactivity at day 1 and about 7% are observed 30 and 60 days after axotomy. In order to further characterize newly GAL‐ and VIP‐positive PGN, their cell diameters were determined 12 days after axotomy. Compared to the mean overall neuron diameter of 24.8 μm, GAL‐immunoreactive neurons are predominantly of small and intermediate size (22.2 μm), whereas VIP occurs mainly in larger neurons (26.1 μm). Besides cell bodies, many intraganglionic nerve fibers stain positive for GAL or VIP, particularly at day 6. Most likely, these fibers represent axons, as indicated by the absence of MAP2, a cytoskeletal protein found in neuronal somata and dendrites. They establish direct membrane contacts with postganglionic perikarya, as revealed by pre‐embedding immuno‐electron microscopy. Some cell bodies and fibers contain both peptides. Colocalization of GAL or VIP with tyrosine hydroxylase (TH), the rate‐limiting enzyme of catecholamine synthesis, reveals a reduced immunoreactivity for TH in intensely GAL‐ or VIP‐positive cells, and vice versa at day 6. However, no difference in staining intensity for VIP or GAL, and TH, is observed after 30 and 60 days. Possible implications of GAL and VIP for peripheral nerve regeneration and their regulation by target‐derived factors are discussed. © 1994 Wiley‐Liss, Inc.
Synaptic morphology of substance P terminals on catecholamine neurons in the commissural subnucleus of the nucleus tractus solitarii in the rat
Authors: Chen I‐Li , Cusick Catherine G. , Weber Joseph T. , Yates Robert D. 
Published: February 2005

AbstractThe ultrastructure of substance P‐containing nerve terminals synapsing on catecholamine neurons in the rat commissural subnucleus of the nucleus tractus solitarii (NTScom) was studied using a double immunocytochemical labeling technique. Although there were numerous tyrosine hydroxylase‐immunoreactive (TH‐I) somata present, substance P immunoreactive (SP‐I) cell bodies were only occasionally found in the NTScom. At the light microscopic level, many SP‐I terminals were seen closely associated with TH‐I dendrites and somata. At the electron microscopic level, SP‐I terminals synapsing on TH‐I structures were also readily encountered. SP‐I terminals contained small, clear, and predominantly spherical vesicles (32 ± 4 nm diameter), as well as large dense‐cored vesicles approximately 100 nm in diameter. Postsynaptic TH‐I dendritic profiles of various calibers and somata were encountered. These postsynaptic TH‐I structures often showed postsynaptic densities. The morphological features of the SP‐TH synapses in the present study, that is, the size of synaptic vesicles and the presence of postsynaptic densities, are quite different from those of central carotid sinus afferent synapses reported in our previous study [Chen et al. (1992), J. Neurocytol., 21:137–147]. Therefore, most of the SP terminals of the SP‐TH synapses in the NTScom appear not to originate from the carotid sinus afferents. SP‐I second‐order neurons of the carotid sinus afferent pathway [Chen et al. (1991), J. Auton. Nerv. Syst., 33:97–98] may be one of the possible sources of such terminals. © 1994 Wiley‐Liss, Inc.
Intersection of first order laue zone lines along the [100] direction in an fcc material
Authors: Curzon A. E. 
Published: February 2005

AbstractAn analytical result is given for the wavelength at which two or more first order Laue zone (FOLZ) lines intersect at a single point on the positive x axis when a face centred cubic crystal is observed in the convergent beam mode with the beam axis parallel to the [001] direction. The position of the intersection along the x axis is also given. The method uses the kinematic approximation of electronic diffraction and the exact hyperbolic form of the FOLZ lines, so that the accuracy is good even for lines that intersect at small angles. © 1994 Wiley‐Liss, Inc.
Effects of vasectomy on the epididymis
Authors: Flickinger Charles J. , Howards Stuart S. , Herr John C. 
Published: February 2005

AbstractCommon principles can be discerned in the response of the epididymis to vasectomy, despite species differences. Increases in the size and number of lysosomes are the most frequent changes in the epididymal epithelium. The presence or absence of additional alterations such as changes in the height of the epithelium may be related to variations in distensibility of the vas deferens and epididymis. Direct measurements by micropuncture of epididymal and seminiferous tubule hydrostatic pressure indicate that, contrary to dogma, increased pressure in the distal epididymis after vasectomy is not generally transmitted to the seminiferous tubules. The epididymal interstitium shows microscopic changes indicative of chronic inflammation, with infiltration of macrophages, lymphocytes, and plasma cells, and rats with these lesions have higher antisperm antibody levels than animals lacking epididymal changes. Macrophages and neutrophils may enter the duct through the epididymal epithelium, at sites of rupture of the duct, and in the efferent ductules. Cyst‐like spermatic granulomas occur in virtually all species where the epididymis or vas deferens ruptures with escape of spermatozoa. The sites and timing of granuloma formation may depend on the mechanical properties of the tract in different species, and they are probably important in the immune response to vasectomy. Postvasectomy sera in Lewis rats recognize a consensus repertoire of dominant autoantigens that closely resembles the antigens bound by sera from rats immunized with isologous spermatozoa. There are multiple routes for disposal of the sperm that continue to be produced after vasectomy. © 1995 Wiley‐Liss, Inc.
Structural investigations of recently discovered high Tc superconductors
Authors: Van Tendeloo G. , Krekels T. , Amelinckx S. , Babu T. G. N. , Greaves C. , Hervieu M. , Michel C. , Raveau B. 
Published: February 2005

AbstractA short overview is given of the possibilities of electron microscopy in the determination of the local, atomic scale structure of high Tc superconducting materials. Examples include the detection of weak oxygen ordering, description and characterization of deformation modulations in layered superconductors, and analysis of very long period superstructures. The ordering principles for tetrahedral chains in Ga‐, Co‐, or Al‐substituted YBCO are discussed and their complex defect structures are described. The incommensurate modulation in YBCO‐based materials containing SO4‐tetrahedra, centered on the Cu(1) sites of the CuO‐chain plane is attributed to the ordering of b‐oriented SO4‐rich chains in the Cu(1)‐S‐O layer; the structure is described in terms of an SO4‐concentration wave. As examples of the new mercury‐based superconducting family we discuss Y0.6Ca0.4Ba2Hg1−xMxCu2O6+y, which crystallizes in the space group P4/mmm with a = 0.3870(1) nm, c = 1.2537(1) nm. This cuprate belongs to the 1212 series; susceptibility measurements show a Tc (onset) of 90K, with a diamagnetic volume fraction of 27% at 4.2K to be reached. A second example is related to the compound Tl2HgBa4Cu2O10+y, in which ordering between single Hg layers and double Tl layers is observed. © 1995 Wiley‐Liss, Inc.
HREM study of the crystal chemistry of the alkaline‐earth cupric oxides stabilized at high pressure
Authors: Hiroi Z. 
Published: February 2005

AbstractThe crystal chemistry of the alkaline‐earth cupric oxides stabilized at high pressure was studied by high‐resolution electron microscopy. Two families of superconductors, (Ca1−ySry)1−xCuO2 and Srn+1Cun O2n+1+δ (n = 1, 2), and one series of semiconductors, Srn−1Cun+1 O2n, are reported. Their structural characteristics are systematically interpreted on the basis of the simple infinite‐layer structure seen in SrCuO2. Microstructures and their relevance to high‐Tc superconductivity are discussed, particularly in the alkaline‐earth‐deficient infinite‐layer phase. © 1995 Wiley‐Liss, Inc.
Shadow images for in‐line holography in a STEM instrument
Authors: Wang Shi‐Yao , Cowley J. M. 
Published: February 2005

AbstractIn a dedicated STEM instrument equipped with a field emission gun, shadow images are easily obtained and have many uses. They are very sensitive to misalignment of the instrument and astigmatism, and therefore can be used for rapid and accurate alignment of the microscope. For crystalline materials, the shadow image contains both the bright‐field and dark‐field images. It is a summation of the transmitted and diffracted beams, and is basically a kind of Gabor's in‐line hologram. Under small or medium defocus, shadow images of a thin, well‐orientated crystalline specimen take the characteristic form of Ronchigrams, which offer a unique means to calibrate the microscope operation parameters, such as the spherical aberration coefficient Cs and defocus settings of the objective lens, with high accuracy. With the calibrated values of Cs and δ, a transfer function of the objective lens may be generated. In the stage of numerical reconstruction, by adapting this transfer function to the experimentally recorded hologram the lens aberration introduced in forming the hologram may be corrected and an improved resolution may be achieved for electron microscope images. © 1995 Wiley‐Liss, Inc.
Freeze‐fracture study of Bodo sp. (Kinetoplastida: Bodonidae)
Authors: Vommaro Rossiane Claudia , Attias Márcia , De Souza Wanderley 
Published: February 2005

AbstractFreeze‐fracture technique was used to analyse the structure of conventionally fixed and quickly frozen Bodo sp., a free‐living kinetoplastid. In the former method, chemically fixed and cryopreserved cells presented a corrugated membrane pattern in the flagella and cell body surfaces. In the latter, however, replicas from quickly frozen unfixed flagellates showed membranes with a smoother aspect, allowing the observation of intramembranous particles (IMPs) on the fracture faces, hardly detectable in previously fixed samples. The IMPs were randomly distributed throughout the cell surface, except in the sparsely seen short IMP rows. © 1995 Wiley‐Liss, Inc.
Development and postnatal regulation of adult myoblasts
Authors: Yablonka‐Reuveni Zipora 
Published: February 2005

AbstractThe myogenic precursor cells of postnatal and adult skeletal muscle are situated underneath the basement membrane of the myofibers. It is because of their unique positions that these precursor cells are often referred to as satellite cells. Such defined satellite cells can first be detected following the formation of a distinct basement membrane around the fiber, which takes place in late stages of embryogenesis. Like myoblasts found during development, satellite cells can proliferate, differentiate, and fuse into myofibers. However, in the normal, uninjured adult muscle, satellite cells are mitotically quiescent. In recent years several important questions concerning the biology of satellite cells have been asked. One aspect has been the relationship between satellite cells and myoblasts found in the developing muscle: are these myogenic populations identiacal or different? Another aspect has been the physiological cues that control the quiescent, proliferative, and differentiative states of these myogenic precursors: what are the growth regulators and how do they function? These issues are discussed, referring to previous work by others and further emphasizing our own studies on avian and rodent satellite cells. Collectively, the studies presented indicate that satellite cells represent a distinct myogenic population that becomes dominant in late stages of embryogenesis. Moreover, although satellite cells are already destined to be myogenic precursors, they do not express any of the four known myogenic regulatory genes unless their activation is induced in the animal or in culture. Furthermore, multiple growth factors are important regulators of satellite cell proliferation and differentiation. Our work on the role of one of these growth factors [platelet‐derived growth factor (PDGF)] during proliferation of adult myoblasts is further discussed with greater detail and the possibility that PDGF is involved in the transition from fetal to adult myoblasts in late embryogenesis is brought forward. © 1995 Wiley‐Liss, Inc.
Confocal microscopy of thick sections from acrylamide gel embedded embryos
Authors: Germroth Patricia G. , Gourdie Robert G. , Thompson Robert P. 
Published: February 2005

AbstractThe preparation of optically clear, thick sections of fragile embryonic tissues greatly aids the power of confocal scanning laser microscopy in imaging three‐dimensional structures. We report here conditions for embedding, sectioning, and staining embryos in polyacrylamide gels for a variety of confocal imaging techniques. Infiltration of tissues in standard mixtures of 10–15% acrylamide monomer yields, upon polymerization, blocks that cut easily by vibratome between 50 and 1,000 μm. These conditions worked well for tissues previously stained or for staining gel sections with low molecular weight water‐soluble fluorochromes (MW < 5 kD [e.g., propidium iodide, phalloidin]). For immunostaining of tissue after embedding and sectioning, the acrylamide concentration was reduced to 2–3% acrylamide to allow access of immunoglobulins to antigenic sites; such gels were supplemented with 1% agarose to facilitate sectioning and handling. Either method yielded abundant, optically clear, and easily handled sections for mounting and examination in water‐miscible media. © 1995 Wiley‐Liss, Inc.
Immunogold studies on peroxisomes: Review of the localization of specific proteins in vertebrate peroxisomes
Authors: Usuda Nobuteru , Hanai Toru , Nagata Tetsuji 
Published: February 2005

AbstractPeroxisomes, since their discovery as microbodies, have been studied mostly independently by electron microscopists and biochemists. The fine structure has been studied by electron microscopy, and the compositional enzymes and proteins by protein biochemistry. Electron microscopic histochemistry has been used to try to clarify the relationship between the fine structure and its constituents. The immunogold technique, a combination of electron microscopy and protein biochemistry, for the first time resolved this problem due to the high sensitivity and resolution power of the staining and the high reliability of the technique. The present paper reviews the way in which the immunogold techniques, especially the protein A‐gold technique, revealed the localization of various enzymes or proteins in peroxisomes or peroxisomal subcompartments, and discusses why this technique should be employed in peroxisome research. © 1995 Wiley‐Liss, Inc.
Quantitative immunocytochemical study of secretory protein expression in parotid glands of rats chronically treated with isoproterenol
Authors: Vugman Ithamar , Hand Arthur R. 
Published: February 2005

AbstractChronic treatment of mice and rats with isoproterenol (IPR) causes marked hypertrophy and hyperplasia of the salivary glands, and alters the expression of several secretory proteins. We used quantitative postembedding immunogold labeling to study the cellular responses in the rat parotid gland during daily (up to 10 days) injections of IPR and during recovery (up to 14 days) after cessation of IPR treatment. Labeling densities of acinar cell secretory granules with antibodies to amylase and protein SMG‐B1 (cross‐reactive with the rat homologue of Parotid Secretory Protein, PSP) fell to 10% of control levels after 8–10 IPR injections, then increased during recovery, paralleling previous biochemical determinations of changes in protein and mRNA levels. With antibodies to proline‐rich proteins (PRP), labeling densities initially fell, then subsequently showed considerable variability, but never exceeded control levels. These results contrast with biochemical determinations showing a marked induction of PRP synthesis, and may have both immunological and structural explanations.Occasional intercalated duct cells located close to the acini underwent differentiation toward an acinar‐like phenotype as a result of IPR treatment. After 1–2 IPR injections, the secretory granules of these cells labeled with antibodies to amylase and PRP. Subsequently, the granules appeared electron‐lucent and were increased in size and number. These observations support earlier work, suggesting that intercalated duct cells may differentiate into other gland cell types.
Immunocytochemical investigation of the in vivo endocytosis by renal tubular epithelial cells
Authors: Gómez‐Pascual Amparo , Londoño Irene , Ghitescu Lucian , Desjardins Michel , Bendayan Moöse 
Published: February 2005

AbstractThe internalization and degradation of glomerular filtered serum proteins by the proximal tubular epithelium has been extensively studied by microperfusion methods. By using a cationic probe that easily traverses the glomerular wall into the urinary space, we have performed a morpho‐cytochemical and quantitative study of the in vivo endocytotic activity of the proximal tubular epithelial cell. Bovine serum albumin (BSA) was tagged with dinitrophenol (DNP) and cationized to pI over 8. It was introduced into the circulation of normal mice for 5, 10, and 30 minutes and the distribution of the labeling was determined by protein A‐gold immunocytochemistry, using specific antiDNP antibodies on tissue sections of routinely aldehyde‐fixed, osmiumpostfixed, and Epon‐embedded kidneys. Cationic BSA‐DNP was detected at the endothelial and epithelial sides of the glomerular basement membrane, and over capillary and tubular basement membranes. In the proximal tubular epithelial cell, labeling was present over microvilli as well as over endosomal and lysosomal compartments, with labeling intensities varying from one compartment to the other. Morphometric evaluations of the labeling demonstrated a progressive incorporation of the probe from microvilli and endocytic compartments at 5 minutes to endocytic and lysosomal compartments at 10 and then 30 minutes. When considering labeling densities, no significant differences were found on microvilli and basolateral membranes between times of circulation; however, the labeling density over endosomal and lysosomal compartments was very intense at 10 minutes compared with 5 minutes, decreasing at 30 minutes. Results from this study validate the cationic albumin tagged with DNP as a tool in the study of the quantitative aspects of protein endocytosis at the ultrastructural level, in the kidney tubular epithelium. © 1995 Wiley‐Liss, Inc.
Cellular functions during activation and damage by pathogens: Immunogold studies of the interaction of bacterial endotoxins with target cells
Authors: Risco Cristina , da Silva Pedro Pinto 
Published: February 2005

AbstractBacterial endotoxins (lipopolysaccharides or LPS) are active components of Gramnegative bacteria that act on numerous cellular functions through the processes of cell activation and damage. The molecular mechanisms involved in the “endotoxic phenomenon” are not defined yet, although extensive studies have been carried out. Immunogold and electron microscopy (EM) have contributed to identify the primary target cells of endotoxins and the subcellular systems that receive the direct action of these bacterial agents. Here, we review our studies on immunogold detection of endotoxins in cellular and subcellular systems. The analysis of the interaction between endotoxins and cells was focussed on the following aspects: (1) morphological characteristics of the LPS aqueous suspensions used in experimental work; (2) binding of endotoxins to the plasma membrane of type II pneumocytes and alveolar macrophages (two of their cellular targets), and influence of the state of aggregation of the LPS; (3) movement and distribution of endotoxins inside the cell, from the plasma membrane to the nucleoplasm; and (4) interaction of LPS with microtubules and its effects on the integrity of the microtubular network. These approaches provide information at the molecular level as well as data for the establishment of physiological models of endotoxicity. © 1995 Wiley‐Liss, Inc.
Immunogold labeling of oncogenic and tumor related proteins
Authors: Rulong Shen , Zhou Renping , Tsarfaty Ilan , Hughes Steven , Woude George Vande , da Silva Pedro Pinto 
Published: February 2005

AbstractImmunogold labeling electron microscopy technique has been used to study the ultrastructural localization of oncogenic proteins: Mos, Met, Ski, and the tumor‐associated protein, Muc1, as well as their relationship with other tumor‐related proteins. By pre‐ and postembedding immunogold labeling electron microscopy techniques, we showed that the Mos protein pp39mos colocalized with microtubule bundles, suggesting that microtubulin or microtubule‐associated protein(s) may be the substrate of Mos. Met protein was labeled at the microvilli of the lumen that are formed in cultured T47D cells, implying its potential involvement in lumen formation. Ski localization experiments revealed a unique globular structure “Ski body” that is present inside the nucleus of interphase chicken embryo fibroblast infected with Ski cDNA FB29 and FB2–29. Ski bodies were also found scattered in the cytoplasm of metaphase FB29 and FB2–29 Ski expressing chicken embryo fibroblasts. In T47D cells, tumor‐associated protein Muc1 was associated with both the plasma membrane and the membranes of secretory vesicles in the cytoplasm. In MUC1 infected NIH3T3 cells, however, labeling showed that in addition to the plasma membrane and the membranes of secretory vesicles, some Muc1 gold spheres were seen inside the secretory vesicles, suggesting that the subcellular localization of the protein may vary in different cell types. © 1995 Wiley‐Liss, Inc.