bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation of isolated nuclei from K 562 haemopoietic cell line for high resolution scanning electron microscopy
Authors: Reipert Siegfried , Allen Terence David , Reipert Birgit Maria 
Published: February 2005

AbstractThe aim of the work is to visualise nuclear pore complexes (NPCs) in mammalian cells by high resolution scanning electron microscopy. A detergent‐free isolation protocol was employed to obtain clean nuclei from the haemopoietic cell line K 562. Nuclear isolation was performed by mechanical homogenisation under hypotonic conditions followed by purification of the nuclear fraction. The isolated nuclei were attached to silicon chips, fixed, critical point dried, and sputter coated with a thin film (3–4 nm) of tantalum. Analysis of the nuclear surface by scanning electron microscopy (SEM) revealed a strong sensitivity of the outer nuclear membrane (ONM) to disruption during the isolation procedure. A significant reduction of the characteristic pattern of damage to the ONM was achieved by means of an isopicnic centrifugation on an isoosmolar balanced Percoll gradient. Analysis of the population of isolated nuclei by flow cytometry showed no signs of cell cycle specific losses of nuclei during isolation. The SEM investigations of the morphology of the nuclear envelope (NE) and of substructural details of NPCs and polyribosomes were performed using an in‐lens field emission scanning electron microscope. © 1994 Wiley‐Liss, Inc.
Three‐dimensional organization of biological tissues: A new method for investigation using scanning electron microscopy
Authors: Kolpakov Valeri , Rekhter Mark , Mironov Alexander 
Published: February 2005

AbstractA new method is described which enables the visualization of hidden cellular surfaces of biological tissues. The method does not depend on the kind of fixative solution, the duration of the fixation, or the quantity of extracellular matrix. The samples are chemically dissociated with potassium ethoxide until the first individual cells appear in the solution. This initial process is followed by phase contrast microscopy, and remaining tissue is investigated with scanning electron microscopy. The method has proved more effective than conventional enzymatic techniques and is a simple, quick, and effective way to investigate the three‐dimensional organization of different normal and pathological tissues. © 1994 Wiley‐Liss, Inc.
Immunohistochemical demonstration of galanin‐, and galanin message‐associated peptide‐like immunoreactivities in sympathetic ganglia and adrenal gland of the guinea pig
Authors: Elfvin L.‐G. , Höukfelt T. , Bartfai T. , Bedecs K. 
Published: February 2005

AbstractUsing the indirect immunofluorescence method, the distribution of galanin (GAL)‐ and galanin message‐associated peptide (GMAP)‐like immunoreactivities (LI) were studied in sympathetic ganglia and the adrenal gland of the guinea pig. A rather dense network of GAL‐immunoreactive nerve fibers was found in the inferior mesenteric ganglion (IMG) and in the superior mesenteric pole of the celiac‐superior mesenteric ganglion complex (C‐SMG). The celiac pole of the C‐SMG, the stellate ganglion, and the superior cervical ganglion contained fewer, mostly scattered fibers. SIF‐cells in prevertebral and paravertebral ganglia contained GAL‐LI, as did the adrenal medullary cells. The GAL fibers in the IMG surrounded mainly principal ganglion cells containing somatostatin‐immunoreactivity (SOM‐IR), whereas fewer fibers were seen around neuropeptide Y (NPY) cells and cells in which SOM and NPY coexisted. Application of colchicine or vinblastine onto the IMG did not result in the appearance of GAL‐IR in the principal ganglion cells. In denervation experiments it was revealed that most of the GAL fibers reach the IMG via the lumbar splanchnic nerves.GAL‐IR appears to be colocalized with substance P (SP) in fibers of the IMG, indicating an origin of the GAL‐containing fibers in dorsal root ganglia (DRG). This conclusion was supported by the finding in lumbar DRGs of GAL‐positive cell bodies that contained SP. The role of GAL in prevertebral ganglia is unclear. It may be suggested that GAL modulates the slow, long‐lasting membrane depolarization of the principal ganglion cells caused by SP in the primary afferents related to the IMG. GMAP‐LI was detected in SIF cells and adrenal medullary cells in which GMAP‐LI parallels the immunoreactivity of GAL. GMAP‐LI was not observed in neuronal cell bodies or nerve fibers of the ganglia. © 1994 Wiley‐Liss, Inc.
Effects of phospholipase A2 inhibitors on the antidepressant‐induced axonal regeneration of noradrenergic locus coeruleus neurons
Authors: Nakamura Shoji 
Published: February 2005

AbstractIn previous experiments, we have shown that antidepressants such as desipramine (DMI) can induce axonal regeneration of noradrenergic locus coeruleus neurons. In this article, we suggest that phospholipase A2 is involved in the molecular mechanism of the antidepressant‐induced regeneration of brain noradrenergic axons. The effects of the PLA2 inhibitors, mepacrine (MEP) or 4‐bromphenacyl bromide (BPB), upon the DMI‐induced regeneration of noradrenergic axons in the rat cerebral cortex were assessed by either histofluorescence or immunohistochemistry using an antibody to dopamine‐beta‐hydroxylase. Symmetrical sites of the frontal cortex in both hemispheres were pretreated with 6‐hydroxydopamine (6‐OHDA). Then, the same cortical site of one hemisphere was infused with DMI by means of osmotic minipumps for more than 2 weeks, while the corresponding cortical site of the other hemisphere was infused with DMI plus MEP or BPB. It was found that the PLA2 inhibitors could attenuate the DMI‐induced regeneration of noradrenergic axons. Thus, if axonal retraction or degeneration of brain noradrenergic neurons is involved in the pathogenesis of clinical depression, elucidating the malfunction of the PLA2 systems may provide substantial evidence to aid in our understanding of the cause of depression at the molecular level. © 1994 Wiley‐Liss, Inc.
Dopaminergic innervation of rat locus coeruleus: A light and electron microscopic immunohistochemical study
Authors: Maeda Toshihiro , Kitahama Kunio , Geffard Michel 
Published: February 2005

AbstractDopaminergic innervation of the rat locus coeruleus (LC) was immunohistochemically studied by using monoclonal antibody directed against dopamine (DA) at the light‐ and electron‐microscopic levels. A dense plexus of DA‐immunoreactive (IR) varicose fibers was found not only in the cell body area of the LC but also in the dendritic area. Three hundred and forty DA‐IR terminal boutons were observed. They were distributed in a wide range of diameters of 0.1–1.8 μm but most of them were large (mean value: 0.98 μm). Sixty‐nine percent formed an asymmetric synapse. There were many axo‐spinous connections. Small dendrites less than 0.3 μm in diameter displaying synaptic specialization were mostly dendritic spines (75%). Most of the target dendrites seemed to be noradrenergic in nature. It is suggested that dopaminergic innervation may play a powerful role in control mechanisms of activity of NA‐containing neurons of the LC. © 1994 Wiley‐Liss, Inc.
Three‐dimensional structure of lung elastin demonstrated by scanning electron microscopy/stereo‐pair images
Authors: O'Donnell M. D. , Cottell D. C. , McGeeney K. F. 
Published: February 2005

AbstractThe aim of this study was to expose the inflated 3‐D structure of lung elastin. Formic acid digestion followed by freeze‐drying unveiled the lamellar framework. The 3‐D structure of elastin was well preserved within the alveolar septa and ducts, as demonstrated by scanning electron microscopy/stereo‐pair photography. Elastin fibers are seen in the alveolar septa, which are continuous with the lamellae. The removal of collagen fibers and cells by formic acid was visualised as a function of time: The optimum was 48 hours. Transverse sections still retained some collagen fibrils and partially digested cells in addition to elastin as shown by transmission electron microscopy (TEM). Forme acid digestion followed by critical point drying caused damage to the lamellar structures and they appeared to collapse. Sodium hydroxide digestion combined with freeze‐drying did not preserve the 3‐D lamellar structure of elastin, but converted it into flat ribbonlike bands. The main structures remaining following alkali treatment were identified by TEM as collagen fibrils well preserved in their original locations. © 1994 Wiley‐Liss, Inc.
Confocal imaging of dendritic Ca2+ transients in hippocampal brain slices during simultaneous current‐ and voltage‐clamp recording
Authors: Jaffe David B. , Brown Thomas H. 
Published: February 2005

AbstractChanges in the intracellular Ca2+ concentration ([Ca2+]i) within CA1 hippocampal pyramidal neurons were imaged using confocal laser scanning microscopy in conjunction with Ca2+ ‐sensitive fluorescent indicators. The imaging was performed in thick hippocampal brain slices while simultaneously measuring or controlling electrical activity with sharp microelectrodes or whole‐cell patch‐clamp electrodes. The combination of imaging and electrophysiology was essential for interpreting the changes in [Ca2+]i. We compared the increases in [Ca2+]i produced by either of two methods–direct depolarization of the cell via the somatic electrode or high‐frequency stimulations of synaptic inputs. The increases in [Ca2+]i in the soma and proximal dendrites caused by both methods were of comparable magnitude and they always decayed within seconds in healthy cells. However, the spatial patterns of distal Ca2+ increases were different. Separate sets of synaptic inputs to the same cell resulted in different spatial patterns of [Ca2+]i transients. We isolated and observed what appeared to be a voltage‐independent component of the synaptically mediated [Ca2+]i transients. This work demonstrates that the combination of neurophysiology and simultaneous confocal microscopy is well suited for visualizing and analyzing [Ca2+]i within neurons throughout the CNS and it raises the possibility of routinely relating subcellular [Ca2+]i changes to structural and functional modifications. © 1994 Wiley‐Liss, Inc.
In vivo human corneal confocal microscopy of identical fields of subepithelial nerve plexus, basal epithelial, and wing cells at different times
Authors: Masters Barry R. , Thaer Andreas A. 
Published: February 2005

AbstractA technique is described to obtain time‐lapse reflected light confocal images of cells in the basal epithelium and adjacent wing cell layer from the in vivo human cornea. The technique is based on the sequential relocation of the uniqúe patterns of the subepithelial nerve plexuses immediately posterior to Bowman's membrane. The patterns of individual subepithelial nerve plexuses, as well as perforation points where nerves traverse Bowman's membrane, serve as fixed landmarks. A real‐time, scanning slit, confocal microscope is used to obtain reflected light images of a subepithelial nerve plexus, and the anterior and adjacent fields of basal and wing cells in the in vivo human cornea. All of the photographs are obtained from single video frames without the necessity of frame averaging or digital image processing. The instrument and relocation technique are prerequisites for applying a time‐lapse observation technique to investigate the dynamics of basal cell proliferation and differentiation in the living eye. © 1994 Wiley‐Liss, Inc.
Understanding the neostriatal microcircuitry: High‐voltage electron microscopy
Authors: Wilson Charles J. 
Published: February 2005

AbstractHigh voltage electron microscopy (HVEM) and HVEM tomography of selectively stained cell processes in the neostriatum have offered an alternative to serial thin section reconstruction for accurate 3‐D visualization and measurement of axons, dendrites, and dendritic spines. Tissue preparation is simple and rapid, allowing examination of large numbers of specimens required for quantitation of neuronal morphology. The resolution of the images exceeds that available from any light microscopic technique and is appropriate for measurement of the finest axons and dendritic spine necks. HVEM tomography allows the direct measurement of dendritic surface area, required for computational modeling of synaptic integration. © 1994 Wiley‐Liss, Inc.
Electron microscopic immunolocalization of the 18 and 29 kilodalton secretory proteins in the mouse epididymis: Evidence for differential uptake by clear cells
Authors: Vierula Matti E. , Rankin Tracy L. , Orgebin‐Crist Marie‐Claire 
Published: February 2005

AbstractIn previous studies we reported the synthesis, secretion, and immunolocalization at the light microscopic level of two mouse epididymal proteins, MEP 7 and MEP 10 [Rankin et al. (1992b), Biol. Reprod., 46:747–766]. MEP 7 is the mouse homologue of the rat metalloproteins, AEG/D and E, and MEP 10 is the mouse homologue of the rat retinoic acid binding proteins, B and C. We now describe the immunolocalization of MEP 7 and MEP 10 in the mouse epididymis at the electron microscopic level. MEP 7 was localized in the Golgi apparatus, in small electron‐lucent secretory vesicles, and on microvilli of the principal cells from the distal caput epididymidis to the cauda. The luminal contents were also immunoreactive in these regions of the epididymis. Although some gold particles were associated with the sperm surface, there was no selective concentration of these particles. In addition, MEP 7 was localized in large (600 nm) supranuclear endocytic vesicles and in infranuclear lysosomes. MEP 10 immunoreactivity was also seen on the microvilli of the principal cells of the distal caput and corpus and the luminal contents from the distal caput to the cauda epididymidis. There was no association of gold particles with the sperm surface. In contrast to MEP 7, there was no detectable MEP 10 immunoreactivity on the organelles of the principal cells involved in protein secretion or endocytosis.Clear cells also demonstrated immunoreactivity to MEP 7 and MEP 10. However, the intensity of immunolabeling, and the number of clear cells labeled, was greater with MEP 10 than MEP 7. In the case of MEP 7, the gold particles were located on the large supranuclear endocytic vesicles and on some infranuclear lysosomes, from the proximal corpus to the middle cauda, while in the case of MEP 10, gold particles were predominantly present in infranuclear lysosomes from the distal caput to the middle cauda.These results suggest that the principal cells are involved in both the secretion and endocytosis of MEP 7. The MEP 10 and MEP 7 proteins present in the lumen of the mouse epididymis are endocytosed from the lumen and degraded in the clear cells. However, the process of endocytosis by the clear cells of these two proteins appears to be different. © 1995 Wiley‐Liss, Inc.
Direct observations of arrangements of carbonate groups in oxycarbonate superconductors by high‐resolution electron microscopy
Authors: Matsui Yoshio , Akimitsu Jun 
Published: February 2005

AbstractArrangements of CO3 groups in various types of oxycarbonate superconductors are examined by high‐resolution transmission electron microscopy (HRTEM). Every other B‐site of basic perovskite structure is replaced with CO3 groups in the first carbonate superconductor, (Ba0.56Sr0.44)2Cu1.1(CO3)0.9Oy. The 123‐related oxycarbonate superconductor obtained in a Y‐Ca‐Sr‐Cu‐O system, (Y0.475Ca0.475Sr0.05)Sr2Cu2.4(CO3)0.6Oy, has a superstructure with 2α periodicity due to ordered replacements of Cu‐site with CO3 groups. The non‐superconducting counterpart with 123‐related structure, (Y0.84Sr0.16)2Sr2Cu2.6(CO3)0.4Oy, on the other hand, shows more disordered arrangements of CO3 groups with nearly 3α periodicity. Similar superstructures, due to ordered replacements of Cu sites with CO3 groups, are also observed in the 223‐related oxycarbonate superconductors, (Ln,Ce)2Sr2Cu2.5(CO3)0.5Oy (Ln = Ho, Dy). Homologous series of compounds, (CaSr)n+1Cun(CO3)Oy (n = 1–5), consist of alternate stacking of Sr2Cu(CO3)Oy and SrCuO2 (infinite‐layer) types of blocks. They become superconductive by additionally doping the BO3 group. Another homologous series of Bi‐based oxycarbonate superconductors, (Bi,Pb)2Sr2n+2Cun+1 (CO3)nOy (n = 1–3), contain alternate CuO2 and CO3 layers in between the two (BiO)2 layers. Both mercury (Hg)‐and thallium (TI)‐based oxycarbonate superconductors, MBa2Sr2Cu2(CO3)Oy (M = Hg or TI) show quite unique modulation structures, where both HgO (or TlO) and CO3 layers repeat in the same plane, along [110] in the Hg compound and [100] in the Tl compound, to form longperiod superstructures with wavy distortion of atom planes. © 1995 Wiley‐Liss, Inc.
Preparation of oxide superconductor specimens for TEM examination
Authors: Fendorf Mark , Powers Michael , Gronsky Ronald 
Published: February 2005

AbstractWe have investigated a wide variety of oxide superconductors and report here on a number of techniques that can be effectively used to prepare transmission electron microscopy (TEM) specimens from these materials. Crushing, cleaving, ion milling, ultramicrotomy, and jet polishing all were successfully utilized, and details of each technique, as well as equipment used, are described. Selection among these methods depends both on the starting form of the material and the information required. Ion milling and crushing generally give the best results and have the widest applicability in our particular work, while crushing and cleaving involve the least equipment cost. In some cases, particularly with ion milling and jet polishing, small variations in the details of preparation have a dramatic effect on the success rate. We have found it to be a great advantage that the same techniques can be applied in a similar manner to a whole range of oxide materials, even (with some refinements and special precautions) to those that are extremely oxygen or moisture sensitive. © 1995 Wiley‐Liss, Inc.
Interaction of colloidal gold‐labelled glucosylated albumin with endothelial cell monolayers: Comparison between cryofixation and glutaraldehyde fixation
Authors: Hoying James B. , Chen Shih‐Chieh , Williams Stuart K. 
Published: February 2005

AbstractBovine aortic endothelial cells (BAEC) were exposed to glucosylated albumin‐gold complexes (GgA), and the distribution of the tracers was compared after cryofixation and after glutaraldehyde fixation. Morphometric analysis revealed differences in the GgA distribution depending upon the method of fixation used. In BAEC monolayers cryofixed after 3 min of incubation with GgA, tracer was observed in predominately apically located vesicular elements. After 16 min of incubation, all vesicular elements were labelled, and multivesicular bodies were the prominent labelled structure. In contrast, chemically fixed monolayers exhibited a heterogeneous distribution of GgA within vesicular profiles after 3 min and 16 min of GgA incubation. The differences in tracer distribution depending upon the fixation method must be resolved before the mechanism of vesiclemediated endothelial cell transport function is defined and universally accepted. © 1995 Wiley‐Liss, Inc.
Microstructures in high‐Tc Bi(Pb)‐family 2212 superconductors as revealed by scanning and transmission electron microscopy
Authors: Horiuchi Shigeo , Hirasaka Masao , Tsutsumi Masayuki , Kosuda Kosuke , Szerer M. Y. , Ben‐Dor Lina 
Published: February 2005

AbstractMicrostructures of Bi(Pb)‐family 2212 superconductors, which were prepared by a sol‐gel method with three different compositions, were examined mainly by scanning and transmission electron microscopy. The magnetization of the specimens strongly depends on the ratio between Bi and Pb content, while Tc is almost constant. In specimen 1, prepared with the nominal composition of Bi/Pb = 9/1, small grains of 2212 phase are formed with a minor fraction of some impurity phases. In specimen 2, with Bi/Pb = 17/3, which is optimum from the viewpoint of magnetization, large grains of the 2212 phase are formed during heating at 800°C, also with the impurity phases. In specimen 3, with Bi/Pb = 8/2, the 2212 grains are divided by layers of (Bi0.86, Pb0.14) (Ca0.7, Sr0.3)Ox. Moreover, plate‐like 2212 crystals are severely bent so that small cracks appear often with an inclusion of amorphous substance being rich in Ca and Pb. These layers and cracks must degrade the magnetization. A modulated structure of Bi‐type is formed in the 2212 grains of specimens 1 and 2, while not only Bi‐type but also Pb‐type are formed in specimen 3. The wavelength of Bi‐type is different for each specimen. © 1995 Wiley‐Liss, Inc.
Organ culture of benign, aging, and hyperplastic human prostate
Authors: Pretlow Thomas G. , Yang Bin , Pretlow Theresa P. 
Published: February 2005

AbstractOrgan culture of the human prostate began in the 1970s and was modeled after the work of Lasnitzki and her collaborators in the mouse two decades earlier. In organ culture of human prostates, one sees a rapid increase in epithelial cells and decrease in stromal cells during the first 3–5 days of culture. While modulation of many phenotypic properties occurs, these cultures provide a simple and rapid way to achieve large numbers of human prostatic epithelial cells in cultured tissues that are markedly depleted of stromal cells. There is some evidence that organ cultures are maintained in slightly better functional states in the presence of androgens; however, most of this evidence is less than quantitative. Most organ culture of prostates has been accomplished with tissues from unspecified locations within the prostate; interpretation of cultures carried out in this fashion has been less complete than would have been possible if they had been carried out from specific anatomic locations within the prostate. Careful pathological characterization of locations contiguous to the cultured tissue is mandatory if cultures are to be interpreted meaningfully. © 1995 Wiley‐Liss, Inc.
Instructive induction of prostate growth and differentiation by a defined urogenital sinus mesenchyme
Authors: Timms Barry G. , Lee Curtis W. , Aumüller Gerhard , Seitz Jurgen 
Published: February 2005

AbstractInstructive influences of fetal mesenchyme were examined in heterotypic tissue recombinants consisting of urogenital sinus mesenchyme (UGM) from male and female rats and distal ductal tips from adult rat prostate. Tissues were grown under the renal capsule of male hosts for periods up to 28 days. Resultant growths exhibited typical prostate histology. Expression of lobe‐specific proteins for the ventral (prostatic steroid binding protein [PSBP]) lateral (seminal vesicle secretion II [SVS II]), and dorsal prostate (secretory transglutaminase [TGase]) were examined by immunocytochemistry. Male or female UGM combined with terminal segments of the ventral or dorsal prostate and immunolabeled with antibodies to lobe‐specific proteins demonstrated expression of all three secretory products. The pattern of staining was consistent with a compound inductive response from the UGM. Unique to this study was our ability to use a defined mesenchymal tissue (female ventral mesenchymal pad [VMP]). This tissue is specifically associated with ductal branching morphogenesis and cytodifferentiation of the ventral prostate. Distal ductal tips from the dorsal lobe of the adult male prostate when recombined with female VMP and grown in vivo exhibited transformation of secretory phenotype, and the epithelium expressed mRNAs for PSBP. Immunocytochemistry of serial sections did not demonstrate labeling for TGase in the new epithelial growth. Ultrastructural analysis of the heterotypic recombinants indicated that the epithelium had similar characteristics to those of normal ventral prostate. Early stages of the mesenchymal‐epithelial interactions resulted in dedifferentiation of the adult epithelium to solid cords of stratified cells. These findings illustrate the potent instructive capacity of a defined fetal UGM to influence development and cytodifferentiation of adult prostate epithelium. © 1995 Wiley‐Liss, Inc.