bluuebunny/crossref_metadata_2025 huggingface dataset:
Cyto‐ and chemoarchitecture of the cerebral cortex of the Australian echidna (Tachyglossus aculeatus). I. Areal organization
Authors: Hassiotis Maria , Paxinos George , Ashwell Ken W.S.
Published: June 2004

We have examined the topography of the cerebral cortex of the Australian echidna (Tachyglossus aculeatus), using Nissl and myelin staining, immunoreactivity for parvalbumin, calbindin, and nonphosphorylated neurofilament protein (SMI‐32 antibody), and histochemistry for acetylcholinesterase (AChE) and NADPH diaphorase. Myelinated fibers terminating in layer IV of the cortex were abundant in the primary sensory cortical areas (areas S1, R, and PV of somatosensory cortex; primary visual cortex) as well as the frontal cortex. Parvalbumin immunoreactivity was particularly intense in the neuropil and somata of somatosensory regions (S1, R, and PV areas) but was poor in motor cortex. Immunoreactivity with the SMI‐32 antibody was largely confined to a single sublayer of layer V pyramidal neurons in discrete subregions of the somatosensory, visual, and auditory cortices, as well as a large field in the frontal cortex (Fr1). Surprisingly, SMI‐32 neurons were absent from the motor cortex. In AChE preparations, S1, R, V1, and A regions displayed intense reactivity in supragranular layers. Our findings indicate that there is substantial regional differentiation in the expanded frontal cortex of this monotreme. Although we agree with many of the boundaries identified by previous authors in this unusual mammal (Abbie [1940] J. Comp. Neurol. 72:429–467), we present an updated nomenclature for cortical areas that more accurately reflects findings from functional and chemoarchitectural studies. J. Comp. Neurol. 475:493–517, 2004. © 2004 Wiley‐Liss, Inc.
Immunocytochemical localization of three vesicular glutamate transporters in the cat retina
Authors: Fyk‐Kolodziej Bozena , Dzhagaryan Arturik , Qin Pu , Pourcho Roberta G.
Published: June 2004

Vesicular transporters play an essential role in the packaging of glutamate for synaptic release and so are of particular importance in the retina, where glutamate serves as the neurotransmitter for photoreceptors, bipolar cells, and ganglion cells. In the present study, we have examined the distribution of the three known isoforms of vesicular glutamate transporter (VGLUT) in the cat retina. VGLUT1 was localized to all photoreceptor and bipolar cells, whereas VGLUT2 was found in ganglion cells. This basic pattern of complementary distribution for the two transporters among known populations of glutamatergic cells is similar to previous findings in the brain and spinal cord. However, the axon terminals of S‐cone photoreceptors were found to express both VGLUT1 and VGLUT2 and some ganglion cells labeled for both VGLUT2 and VGLUT3. Such colocalizations suggest the existence of dual modes of regulation of vesicular glutamate transport in these neurons. Staining for VGLUT2 was also present in a small number of varicose processes, which were seen to ramify throughout the inner plexiform layer. These fibers may represent axon collaterals of ganglion cells. The most prominent site of VGLUT3 immunoreactivity was in a population of amacrine cells; the axon terminals of B‐type horizontal cells were also labeled at their contacts with rod spherules. The presence of the VGLUT3 transporter at sites not otherwise implicated in glutamate release may indicate novel modes of glutamate signaling or additional roles for the transporter molecule. J. Comp. Neurol. 475:518–530, 2004. © 2004 Wiley‐Liss, Inc.
Noradrenergic innervation of the developing and mature septal area of the rat
Authors: Antonopoulos John , Latsari Maria , Dori Ioanna , Chiotelli Maria , Parnavelas John G. , Dinopoulos Athanasios
Published: June 2004

ABSTRACT The noradrenergic innervation of the developing and mature septal area of the rat was examined with light and electron microscopic immunocytochemistry using an antibody against dopamine‐β‐hydroxylase. At birth, a small number of relatively thick noradrenergic fibers were found to innervate the lateral septum (mainly its intermediate part) and the nuclei of the vertical and horizontal limbs of the diagonal band of Broca. By postnatal day 7, a substantial increase in their density was observed. At this age some labeled fibers left the medial forebrain bundle and invaded the nucleus of the horizontal limb of the diagonal band. These fibers then ran in a ventrodorsal direction and innervated the nucleus of the vertical limb before entering the medial septum. Immunoreactive fibers were finer and more varicose than at birth. In the subsequent 2 weeks, the density of labeled fibers in the septal area was further increased. By postnatal day 21, the distribution pattern and density of the noradrenergic innervation appeared similar to the adult. In the adult, noradrenergic fibers exhibited more varicosities than in younger rats. Electron microscopic analysis revealed a low proportion (peaked at P7) of noradrenergic varicosities engaged in synaptic contacts throughout development. The overwhelming majority of these synapses were symmetrical, predominantly with small or medium‐sized dendrites. The present findings provide the morphological basis for the functional interactions between noradrenergic afferents and neuronal elements in the septal area. The low proportion of synaptic contacts found in this study suggests that noradrenaline may exert its action in the septal area mainly through transmission by diffusion (volume transmission), as has been suggested for other areas of the developing and adult brain. J. Comp. Neurol. 476:80–90, 2004. © 2004 Wiley‐Liss, Inc.
Effects of spinal nerve ligation on immunohistochemically identified neurons in the L4 and L5 dorsal root ganglia of the rat
Authors: Hammond Donna L. , Ackerman Laurie , Holdsworth Ryan , Elzey Brian
Published: June 2004

This study examined the effect of spinal nerve ligation on different populations of immunohistochemically identified neurons in the dorsal root ganglia (DRG) of the rat. The optical fractionator method was used to count neurons in the ipsilateral L4 and L5 DRG 1–20 weeks after ligation of the L5 and L6 spinal nerves, sham surgery, or no surgery. One week after ligation, neurons in the L5 DRG that were labeled by IB4, a marker of unmyelinated primary afferent neurons, were largely absent. The numbers of IB4‐labeled neurons then progressively increased to reach control values by 20 weeks. A smaller, sustained decrease occurred in the number of small‐, medium‐ and large‐sized neurons immunoreactive for calcitonin gene‐related peptide (CGRP), a marker for peptidergic primary afferents, in the L5 DRG. There was a proportionately greater decrease in the numbers of medium‐ to large‐sized CGRP‐like immunoreactive neurons. The number of myelinated afferents in the L5 DRG, identified by their staining for neurofilament protein (N52), did not change after ligation. However, closer examination revealed a significant decrease in the numbers of large‐sized neurons, coupled with an increase in the numbers of small‐ to medium‐sized neurons, and the appearance of a novel population of very small‐sized neurons labeled by N52. The numbers and cell size distributions of IB4‐labeled, CGRP‐like immunoreactive, and N52‐labeled neurons were unchanged in the adjacent L4 DRG. Unlike the L5 DRG, injury‐induced changes in the expression of various receptors, neurotransmitters and neurotrophic factors in the L4 DRG are not confounded by a change in the immunohistochemical phenotype of primary afferent neurons. J. Comp. Neurol. 475:575–589, 2004. © 2004 Wiley‐Liss, Inc.
An electron microscope immunocytochemical study of GABABR2 receptors in the monkey basal ganglia: A comparative analysis with GABABR1 receptor distribution
Authors: Charara Ali , Galvan Adriana , Kuwajima Masaaki , Hall Randy A. , Smith Yoland
Published: June 2004

Functional γ‐aminobutyric acid (GABA)Breceptors are heterodimers made up of GABABR1 and GABABR2 subunits. The subcellular localization of GABABR2 receptors remains poorly known in the central nervous system. Therefore, we performed an ultrastructural analysis of the localization of GABABR2 receptor immunoreactivity in the monkey basal ganglia. Furthermore, to characterize better the neuronal sites at which GABABR1 and GABABR2 may interact to form functional receptors, we compared the relative distribution of immunoreactivity of the two GABABreceptors in various basal ganglia nuclei. Light to moderate GABABR2 immunoreactivity was found in cell bodies and neuropil elements in all basal ganglia nuclei. At the electron microscope level, GABABR2 immunoreactivity was commonly expressed postsynaptically, although immunoreactive preterminal axonal segments were also frequently encountered, particularly in the globus pallidus and substantia nigra, where they accounted for the third of the total number of GABABR2‐containing elements. A few labeled terminals that displayed the ultrastructural features of glutamatergic boutons were occasionally found in most basal ganglia nuclei, except for the subthalamic nucleus, which was devoid of GABABR2‐immunoreactive boutons. The relative distribution of GABABR2 immunoreactivity in the monkey basal ganglia was largely consistent with that of GABABR1, but some exceptions were found, most noticeably in the globus pallidus and substantia nigra, which contained a significantly larger proportion of presynaptic elements labeled for GABABR1 than GABABR2. These findings suggest the possible coexistence and heterodimerization of GABABR1 and GABABR2 at various pre‐ and postsynaptic sites, but also raise the possibility that the formation of functional GABABreceptors in specific compartments of basal ganglia neurons relies on mechanisms other than GABABR1/R2 heterodimerization. J. Comp. Neurol. 476:65–79, 2004. © 2004 Wiley‐Liss, Inc.
Mesostructured Dye‐Doped Titanium Dioxide for Micro‐Optoelectronic Applications
Authors: Vogel Robert , Meredith Paul , Kartini Indriana , Harvey Michael , Riches Jamie D. , Bishop Alexis , Heckenberg Norman , Trau Matt , Rubinsztein‐Dunlop Halina
Published: June 2004

Optically transparent, mesostructured titanium dioxide thin films were fabricated using an amphiphilic poly(alkylene oxide) block copolymer template in combination with retarded hydrolysis of a titanium isopropoxide precursor. Prior to calcination, the films displayed a stable hexagonal mesophase and high refractive indices (1.5 to 1.6) relative to mesostructured silica (1.43). After calcination, the hexagonal mesophase was retained with surface areas >300 m2 g−1. The dye Rhodamine 6G (commonly used as a laser dye) was incorporated into the copolymer micelle during the templating process. In this way, novel dye‐doped mesostructured titanium dioxide films were synthesised. The copolymer not only directs the film structure, but also provides a solubilizing environment suitable for sustaining a high monomer‐to‐aggregate ratio at elevated dye concentrations. The dye‐doped films displayed optical thresholdlike behaviour characteristic of amplified spontaneous emission. Soft lithography was successfully applied to micropattern the dye‐doped films. These results pave the way for the fabrication and demonstration of novel microlaser structures and other active optical structures. This new, high‐refractive index, mesostructured, dye‐doped material could also find applications in areas such as optical coatings, displays and integrated photonic devices.
Ion–Dipole Interactions in Concentrated Organic Electrolytes
Authors: Chagnes Alexandre , Nicolis Stamatios , Carré Bernard , Willmann Patrick , Lemordant Daniel
Published: June 2004

An algorithm is proposed for calculating the energy of ion–dipole interactions in concentrated organic electrolytes. The ion–dipole interactions increase with increasing salt concentration and must be taken into account when the activation energy for the conductivity is calculated. In this case, the contribution of ion–dipole interactions to the activation energy for this transport process is of the same order of magnitude as the contribution of ion–ion interactions. The ion–dipole interaction energy was calculated for a cell of eight ions, alternatingly anions and cations, placed on the vertices of an expanded cubic lattice whose parameter is related to the mean interionic distance (pseudolattice theory). The solvent dipoles were introduced randomly into the cell by assuming a randomness compacity of 0.58. The energy of the dipole assembly in the cell was minimized by using a Newton–Raphson numerical method. The dielectric field gradient around ions was taken into account by a distance parameter and a dielectric constant of ε=3 at the surfaces of the ions. A fair agreement between experimental and calculated activation energy has been found for systems composed of γ‐butyrolactone (BL) as solvent and lithium perchlorate (LiClO4), lithium tetrafluoroborate (LiBF4), lithium hexafluorophosphate (LiPF6), lithium hexafluoroarsenate (LiAsF6), and lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) as salts.
Search for Resolution of Chiral Fluorohalogenomethanes and Parity‐Violation Effects at the Molecular Level
Authors: Crassous Jeanne , Monier Franck , Dutasta Jean‐Pierre , Ziskind Michaël , Daussy Christophe , Grain Christophe , Chardonnet Christian
Published: June 2004

The first observation of a parity‐violation effect in molecules induced by weak interactions is still a dream that requires the synthesis and, eventually, the resolution of the enantiomers of well‐chosen simple chiral molecules together with an appropriate experimental set‐up for high‐resolution spectroscopy. Performing IR spectroscopy on highly enantiomerically enriched samples of bromochlorofluoromethane succeeded in giving an upper limit of 10−13 for the relative vibrational energy difference between the two enantiomers. These results led us to conceive a new experimental set‐up based on a supersonic molecular beam and to work on other chiral molecules, such as chlorofluoroiodomethane. A synthesis of (±)‐CHClFI from racemic chlorofluoroiodoacetic acid should, in the near future permit the preparation of optically active samples of this haloform. The development of molecular beam spectroscopy using a two‐photon Ramsey‐fringes experiment should allow us to reach the precision needed to observe parity violation. These experimental challenges, which stimulate a close collaboration between chemists and physicists, are presented. The success of these projects would open the route to new information on the molecular Hamiltonian, a better knowledge of the electroweak interaction, and a better control of the various chirality‐related properties of simple molecules.
Electronic Excitation Energy Migration in a Photonic Dye–Zeolite Antenna
Authors: Yatskou Mikalai M. , Meyer Marc , Huber Stefan , Pfenniger Michel , Calzaferri Gion
Published: June 2004

Electronic excitation energy migration in a photonic antenna host–guest material has been investigated by time‐resolved fluorescence experiments and by Monte Carlo calculations. The host consists of a linear channel system (zeolite L). The channels are filled with energy transporting dyes (donors) in their middle section and by one or several monolayers of a strongly luminescent trapping dye (acceptors) at each end of the channels. Excitation energy is transported among the donors in a series of steps until it reaches an acceptor at one end of the channels, or it is somehow trapped on its way, or it escapes by spontaneous emission. We describe the organization of dyes in the channels by means of Monte Carlo simulation and we report time‐resolved data on a variety of pyronine‐, oxonine‐, and oxonine,pyronine–zeolite L materials. In the latter, the pyronine acts as donor and oxonine as acceptor. We find that the luminescence decay of crystals containing only one kind of dye is single exponential for moderate loading if measured under oxygen‐free conditions, but biexponential otherwise. The main characteristic of the time evolution of oxonine,pyronine–zeolite L crystals is that the acceptor intensity is first built up before it starts to decay. This intensity increase becomes faster with increasing donor loading, a fact that beautifully supports the interpretation that the crystals behave as photonic antenna in which excitation energy is transported preferentially along the channels by a Förster‐type mechanism until it reaches the acceptor, where it is emitted as red luminescence.
Large‐Area Synthesis of Carbon Nanofibers by Low‐Power Microwave Plasma‐Assisted CVD
Authors: Zhong G. , Tachiki M. , Umezawa H. , Fujisaki T. , Kawarada H. , Ohdomari I.
Published: June 2004

Novel antenna edge microwave plasma CVD (AE‐MPCVD) is used for the first time to grow CNFs (carbon nanofibers). The synthesis of CNFs on large‐area substrates with high growth reproducibility is reported at low microwave power input and with remote deposition. A growth area ten times as large as the plasma size generated is achieved by AE‐MPCVD. Because of its structural simplicity, AE‐MPCVD systems can easily be scaled up by applying multi‐antenna edge arrays without considering complex microwave geometry or cavity and the total growth area and quality of CNFs are thus expected to be greatly improved.
Synthesis and Characterization of Tris(β‐ketoiminato)ruthenium(III) Complexes: Potential Precursors for CVD of Ru and RuO2 Thin Films
Authors: Chou T.‐Y. , Lai Y.‐H. , Chen Y.‐L. , Chi Y. , Prasad K.R. , Carty A.J. , Peng S.‐M. , Lee G.‐H.
Published: June 2004

The synthesis and characterization of RuIII metal complexes [Ru(keim1)3] (1) and [Ru(keim2)3] (2) are reported, where (keim)H is an abbreviation for the fluorinated ketoimine ligands with formula HOC(CF3)=CHCR=NMe; (keim1)H with R = Me and (keim2)H with R = CF3. These newly synthesized complexes were characterized by spectroscopic methods, while the second complex, 2, was further examined by single‐crystal X‐ray diffraction (XRD), revealing an octahedral coordination for the Ru cation, with three ketoiminate arranged in a mer‐configuration, a consequence of the enhanced steric interaction between ligands. Moreover, both Ru metal complexes show good volatility and thermal stability. CVD experiments were conducted using these complexes at temperatures of 325–450 °C. The Ru metal and RuO2 thin films on silicon wafers were successfully obtained using either a mixture of 2 % O2 in argon or pure O2 as the carrier gas, respectively. Our result shows that a 2 % O2 concentration induces the formation of Ru metal, while that only complex 1 gives formation of a columnar RuO2 phase upon switching to pure O2 as the CVD carrier gas. Scanning electron microscopy (SEM) images were taken to reveal surface morphologies, while X‐ray photoelectron spectroscopy (XPS) and XRD were utilized to access their atomic composition as well as the intrinsic packing of the as‐deposited thin film materials.
Growth Per Cycle in Atomic Layer Deposition: A Theoretical Model (Chem. Vap. Deposition 2003, 9, 249)
Authors: Puurunen R.L.
Published: June 2004

To view the original paper use http://dx.doi.org/10.1002/cvde.200306265.
Proliferative response of bystander cells adjacent to cells with incorporated radioactivity
Authors: Gerashchenko Bogdan I. , Howell Roger W.
Published: June 2004

Background

In a recent study, we showed that cells irradiated with γ‐rays stimulate cell growth of unirradiated (bystander) cells, when the two populations are co‐cultured as a mixture (Cytometry 2003;54A:1–7). Direct cell‐to‐cell contact appears to be a prerequisite for the proliferative response of the bystander cells (Cytometry, 2003 56A:71–80). The aim of the current work is to investigate the possible proliferative bystander effects caused by intracellular irradiation with incorporated radionuclides, specifically the short‐range β particle emitter, tritium (3H).

Methods

Subconfluent monolayers of rat liver epithelial cells (WB‐F344) were incubated in the presence of (methyl‐3H)thymidine (3HTdR) at concentrations ranging between 5.2 kBq/ml and 57.8 kBq/ml for 18 h. Radiolabeled cells, containing between 0.7 × 10−3 Bq/cell and 8.8 × 10−3 Bq/cell were mixed with unlabeled (i.e., bystander) cells in a ratio of 1:1 and cultured together for 24 h followed by an flow cytometry (FCM) study of their proliferation. In order to discriminate the two populations of co‐cultured cells, one cell population (unlabeled bystander cells) was stained with carboxyfluorescein diacetate, succinimidyl ester (CFDA SE), which metabolizes intracellularly. The absorbed doses received by the radiolabeled cells that contained 0.7 × 10−3, 2.5 × 10−3, and 8.8 × 10−3 Bq/cell were 0.14, 0.49, and 1.7 Gy, respectively.

Results

Cells that were not treated with tritiated thymidine (unlabeled cells), in the presence of radiolabeled cells that received absorbed doses from 0.14–1.7 Gy, showed enhanced cell growth by approximately 9 to 10%.

Conclusions

Cells labeled with 3HTdR can induce increased proliferation in neighboring unlabeled bystander cells. FCM provides an excellent basis for characterization of proliferative bystander effects in co‐culture systems. © 2004 Wiley‐Liss, Inc.
Automated counting of mammalian cell colonies by means of a flat bed scanner and image processing
Authors: Dahle Jostein , Kakar Manish , Steen Harald B. , Kaalhus Olav
Published: June 2004

Background

Clonogenic assays are used frequently to measure the cell killing and mutagenic effects of radiation and other agents. Clonogenic assays carried out manually are tedious and time‐consuming and involve a significant element of subjectivity. However, several commercial automatic colony counters are available. Based on CCD video imaging and image analysis they are relatively expensive and can analyze only one petri dish at a time.

Method

We have developed a cheaper and more efficient device, which employs a flat bed scanner to image 12 60‐mm petri dishes at a time. Two major problems in automated colony counting are the clustering of colonies and edge effects. By using standard image analysis and implementing an inflection point algorithm, these problems were greatly diminished. The resulting system was compared with two manual colony counts, as well as with automated counts with the Oxford Optronix ColCount colony counter for cell lines V79 and HaCaT.

Results

Comparisons assuming the manual counts to be correct showed that our automatic counter was slightly more accurate than the commercial unit.

Conclusions

As a whole, our automated colony counter performed significantly better than the commercial unit with regard to processing time, cost and accuracy. © 2004 Wiley‐Liss, Inc.
Chromatic shifts in the fluorescence emitted by murine thymocytes stained with Hoechst 33342
Authors: Petersen Timothy W. , Ibrahim Sherrif F. , Diercks Alan H. , van den Engh Ger
Published: June 2004

Background

Many methods in flow cytometry rely on staining DNA with a fluorescent dye to gauge DNA content. From the relative intensity of the fluorescence signature, one can then infer position in cell cycle, amount of DNA (i.e., for sperm selection), or, as in the case of flow karyotyping, to distinguish individual chromosomes. This work examines the staining of murine thymocytes with a common DNA dye, Hoechst 33342, to investigate nonlinearities in the florescence intensity as well as chromatic shifts.

Methods

Murine thymocytes were stained with Hoechst 33342 and measured in a flow cytometer at two fluorescence emission bands. In other measurements, cells were stained at different dye concentrations, and then centrifuged. The supernatant was then used for a second round of staining to test the amount of dye uptake. Finally, to test for resonant energy transfer, we measured fluorescence anisotropy at two different wavelengths.

Results

The fluorescence of cells stained with Hoechst 33342 is a nonlinear process that shows an overall decrease in intensity with increased dye uptake, and spectral shift to the red. Along with the spectral shift of the fluorescence to the longer wavelengths, we document decreases in the fluorescence anisotropy that may indicate resonant energy transfer.

Conclusions

At low concentrations, Hoechst 33342 binds to the minor groove of DNA and shows an increase in fluorescence and a blue shift upon binding. At higher concentrations, at which the dye molecules can no longer bind without overlapping, the blue fluorescence decreases and the red fluorescence increases until there is approximately one dye molecule per DNA base pair. The ratio of the blue fluorescence to the red fluorescence is an accurate indicator of the cellular dye concentration. © 2004 Wiley‐Liss, Inc.
Use of SYBR14, 7‐amino‐actinomycin D, and JC‐1 in assessing sperm damage from rats with spinal cord injury
Authors: Nunez Rafael , Murphy Thomas F. , Huang Hosea F. , Barton Beverly E.
Published: June 2004

Background

Although fluorescent dyes combined with flow cytometry have been used to confirm the viability of sperm in the past, methods to detect damage to spermatozoa following injury have been limited to use of dyes, which are often difficult to adequately compensate for in a single laser system.

Methods

In this article, we present what we believe is a better method to assess damage to sperm secondary to spinal cord injury in an in vivo model, for use with a standard Ar laser and flow cell. In this rat model of spinal cord injury leading to sperm damage, the spinal cords of the rats were injured, but the reproductive organs were not. To understand the origins of sperm injury, and to develop ways to overcome the loss of fertility, we used the viability dye SYBR‐14 along with 7‐amino actinomycin D to detect apoptosis. Additionally, we used the dye JC‐1 to measure the changes in mitochondrial transmembrane potential that accompany the damage.

Results

We found that SYBR‐14 plus 7‐amino actinomycin D was a useful method for quantifying apoptosis, particularly when another dye, such as JC‐1, was used simultaneously. By using these dyes in concert with motility studies, we were able to quantify the extent of damage to sperm and correlate it to the decrease in motility of sperm (r2 = 0.99 for SYBR14 versus motility and r2 = 0.98 for JC‐1 versus motility by regression analysis).

Conclusions

With a method established to measure injury to sperm, we hope to determine which treatment regimens of ones we will test are effective in restoring sperm to a more fertile state, in the future. © 2004 Wiley‐Liss, Inc.
“Cellular astronomy”—A foreseeable future in cytometry
Authors: Shapiro Howard M.
Published: June 2004

Advances in electro‐optic technology within the past 2 years, notably the development of high‐intensity light‐emitting diodes and highly efficient charge‐coupled device cameras, have made it feasible to produce small, simple, rugged, automated fluorescence image cytometers, with selling prices well below US $10,000, that can make measurements previously the exclusive domain of flow and scanning cytometers costing many times more. It should be feasible to apply the new cytometric technology in scientific and geographic areas for which a previous generation of instruments was too complex and too expensive, e.g., to problems of diagnosis and management of infectious diseases prevalent at critical levels in resource‐poor areas, such as the human immunodeficiency virus, malaria, and tuberculosis. © 2004 Wiley‐Liss, Inc.
Biegebemessung von bewehrtem Mauerwerk nach dem ω‐Verfahren auf der Grundlage realer Spannungs‐Dehnungs‐Beziehungen
Authors: Mertzsch Olaf
Published: June 2004

Die Tragfähigkeit von bewehrtem Mauerwerk ist in starkem Maße von der Art des verwendeten Mauerwerks abhängig. Dabei wirken sich nicht nur die Festigkeit, sondern auch das Spannungs‐Dehnungs‐Verhalten auf die Tragfähigkeit aus. In /1/ wurde das Spannungs‐Dehnungs‐Verhalten von Mauerwerk untersucht. Die für die weiteren Betrachtungen wesentlichen Ergebnisse sind in Tabelle 1 zusammengestellt. Ein Vergleich dieser Ergebnisse mit den in /2/ und /3/ zugrunde gelegten Ansätzen zeigt, daß hier das reale Dehnungsverhalten nur unzureichend berücksichtigt wird. Aus diesem Grund wurden Berechnungshilfsmittel erarbeitet, mit deren Hilfe das Verformungsverhalten des verwendeten Mauerwerks wirklichkeitsnah berücksichtigt werden kann. Ein Vergleich der maximalen Tragfähigkeit zeigt deutliche Unterschiede, die bei einer Bemessung nach /2/ und /3/ nicht ausreichend berücksichtigt werden.
Zur Biegebemessung von bewehrtem Mauerwerk nach Eurocode 6
Authors: Jäger Wolfram , Baier Gunar
Published: June 2004

Im Rahmen der Überarbeitung des EC 6, Teil 1‐1 in der Fassung der ENV 1996‐1‐1 /1/ erfolgte eine Überprüfung wesentlicher Teile der Passagen zum bewehrtem Mauerwerk /2/. Die Ergebnisse bildeten die Grundlage für die deutsche Stellungnahme. Das Ziel dabei war vorrangig, Sicherheitsrisiken bei der Bemessung von bewehrtem Mauerwerk auszuschließen und eine Modifikation der Bemessungsregeln zu erreichen.

Als ein wesentliches Ergebnis konnte das bisher enthaltene, aus dem British Standard stammende Verfahren zur Biegebemessung von bewehrtem Mauerwerk an die besonderen Eigenschaften der in Deutschland vorzugsweise eingesetzten Stein‐Mörtel‐Kombinationen angepaßt und in die Schlußfassung des Eurocode 6, prEN 1996‐1‐1: 2003‐03 /3/ eingebracht werden. Weitere Themenstellungen, wie z. B. Schubbeanspruchung sowie Bemessung von stabilitätsgefährdeten bewehrten Mauerwerksbauteilen, wurden ebenfalls untersucht. Der nachfolgende Beitrag beschränkt sich auf die Darstellung der Grundlagen der Biegebemessung nach EC 6 und die Berücksichtigung der heute in Deutschland üblichen Mauerwerkarten.
Untersuchungen zur Schubtragfähigkeit von Ziegelmauerwerk
Authors: Roßbach Michael , Schmidt Ulf , Schubert Peter
Published: June 2004

Durch Einwirkung von Wind und auch Erdbeben werden Mauerwerkwände in der Wandebene auf Schub (Scheibenschub) beansprucht. Der Nachweis ausreichender Schubtragfähigkeit erfolgt nach DIN 1053‐1 für Mauerwerk aus genormten Steinen und Mauermörteln bzw. nach entsprechenden allgemeinen bauaufsichtlichen Zulassungen. Aus der bisherigen Auswertung von Schubversuchen an Mauerwerk ergeben sich teilweise erhebliche Festigkeitsreserven. Die nachfolgend beschriebenen theoretischen und experimentellen Untersuchungen sollen dazu beitragen, die bisherigen Untersuchungsergebnisse zu ergänzen und abzusichern und den Erkenntnisstand zur rechnerischen Bestimmung der Schubtragfähigkeit von Mauerwerk zu verbessern — insbesondere in Hinblick auf die derzeitige Überarbeitung von DIN 1053‐1.
Bauausführung der Hauptkuppel
Authors: Spiegel Frank , Uhlmann Thomas
Published: June 2004

Im Juni 1996 wurden von der Niederlassung Dresden der Walter Bau AG vereinigt mit Dywidag als Federführender in Arbeitsgemeinschaften die Arbeiten zum archäologischen Wiederaufbau der Frauenkirche aufgenommen. Beim Mauerwerksbau aus Sandstein waren dabei in Einheit die hohen ästhetischen Anforderungen der Gestaltung als auch die weit über dem Üblichen liegenden ingenieurmäßigen Vorgaben für das Mauerwerk zu bewältigen. Die Errichtung der zweischaligen Hauptkuppel begann unter Nutzung aller bis dahin gesammelten Erfahrungen im Juni 2002 und wurde am 23. Mai 2003 mit dem Setzen des Schlußsteins vollendet.
Das Lehrgerüst der Hauptkuppel
Authors: Noack Mario
Published: June 2004

Bei der Konstruktion des Lehrgerüstes für die Hauptkuppel flossen die Besonderheiten des Bauwerks und die Erfahrungen aus vorangegangenen Lehrgerüstkonstruktionen an der Frauenkirche ein.

Da die Tragwirkung der einzelnen Mauerwerksschichten erst nach Ringschluß und Erreichen der notwendigen Festigkeit des Mörtels entsteht, mußte das Mauerwerk bis dahin unterstützt werden. Die begrenzte Tragfähigkeit der Stützkonstruktion der Lehrschalung machte eine schrittweise Entlastung bereits fertiggestellter Abschnitte der Kuppel erforderlich.

Das auf Schalungs‐ und Gerüstbau spezialisierte Ingenieurbüro Noack war mit der Planung des Lehrgerüstes der Kuppel beauftragt.
Mäßige Vorspannung des Kuppelmauerwerks
Authors: Stoll Volker , Dornacher Siegfried
Published: June 2004

Bei rotationssymmetrischen Kuppeln, die aus Kreisbogenabschnitten erzeugt werden, entstehen unterhalb der oberen Bruchfuge Ringzugkräfte, so auch bei der Kuppel der Frauenkirche. Da Mauerwerk diese nicht oder nur begrenzt aufnehmen kann, müssen umlaufende Anker eingelegt werden. Die Notwendigkeit dazu erkannte intuitiv George Bähr bereits beim Bau der Kuppel (Bild 1).

Beim Wiederaufbau wurden insgesamt sechs robuste Anker aus hochfesten Breitflachstählen in geometrischer Anlehnung an das historische Vorbild in den Mauerwerksverband der Kuppel integriert. Um ihre sofortige Wirksamkeit und damit die Dichtheit der Kuppel zu gewährleisten, wurden sie mäßig vorgespannt. Der Beitrag stellt die gewählte Lösung dar und erläutert deren Ausführung.
Die Laterne als krönender Abschluß
Authors: Jäger Wolfram , Stoll Volker
Published: June 2004

Der obere Abschluß des Steinbaus der Frauenkirche wird wie bei vielen anderen Kirchen von einer Laterne gebildet. Filigran krönt sie das Kirchbauwerk. Die Laterne trägt das hölzerne Laternendach und das Turmkreuz. Gemeinsam mit diesen beiden Bauteilen weist sie mit ca. 30 m eine Höhe auf, die eine baurechtliche Einordnung als Hochhaus erfordern würde.
Detection of high‐risk human papillomavirus (HPV) DNA by Hybrid Capture II in women referred due to atypical glandular cells in the primary screening
Authors: Oliveira Eliane R.Z.M. , Derchain Sophie F.M. , Rabelo‐Santos Silvia H. , Westin Maria Cristina A. , Zeferino Luiz Carlos , Campos Elisabete A. , Syrjanen Kari J.
Published: June 2004

We assessed the detection of high‐risk human papillomavirus DNA (HPV‐DNA) in women examined by a second Pap smear due to atypical glandular cells (AGC) detected in their screening Pap smear. In 91 women included in the study, a second Pap smear was taken and HPV‐DNA test was performed using Hybrid Capture II (HC II). The second Pap smear showed no abnormalities in 28 (31%) cases, ACG in 17 (19%) cases, and high‐grade squamous intraepithelial lesions (HSIL) or worse in 24 (26%). HC II test was positive in 36% of the cases. Considering the second Pap smear diagnosis, HPV‐DNA was detected in 87% of the women with HSIL, 100% of women with in situ adenocarcinoma, and only in 11% of the women with no abnormalities. The use of the second Pap smear combined with HPV‐DNA may improve the management of women with AGC in the primary screening. Diagn. Cytopathol. 2004;31:19–22. © 2004 Wiley‐Liss, Inc.
Novel tyramide‐based tyrosinase assay for the detection of melanoma cells in cytological preparations
Authors: Angeletti Cesar , Khomitch Vitali , Halaban Ruth , Rimm David L.
Published: June 2004

Fine‐needle aspiration (FNA) has been used as a fast, minimally invasive, and reliable method for the evaluation of enlarged lymph nodes. However, there are some cases where the definitive diagnosis cannot be elicited with morphology alone, especially cases without a known primary lesion. Although immunocytochemical studies may be helpful in some situations, they are often complicated by nonspecific staining. Recently, a novel tyramide‐based tyrosinase assay was developed. Since melanocytes, both benign and malignant, produce tyrosinase, we postulated that this assay could be useful as an in situ biochemical diagnostic test. We modified the Perkin Elmer TSA assay, a commercial assay based on tyramide, a tyrosine analog that is a substrate for tyrosinase, for use on air‐dried cytological preparations. We validated the assay on cell lines, then tested a small series of melanoma and nonmelanoma cytology specimens. The YUGEN8 melanoma cell line was used to optimize the assay and it showed abundant reaction product, while HeLa cells served as a negative control. All melanoma cytology specimens were positive and all nonmelanoma specimens were negative. These results suggest that this simple, fast, and inexpensive assay is a sensitive and specific method for detection of melanoma cells in cytology specimens. This method may be a useful ancillary procedure for the resolution of challenging melanoma cases. Diagn. Cytopathol. 2004;31:33–37. © 2004 Wiley‐Liss, Inc.
Atypical teratoid/rhabdoid tumor: Cytology and differential diagnosis in adults
Authors: Raisanen Jack , Hatanpaa Kimmo J. , Mickey Bruce E. , White Charles L.
Published: June 2004

Atypical teratoid/rhabdoid tumors (AT/RTs) are malignant intracranial neoplasms that usually occur in the posterior fossa of children. They are characterized by cells with paranuclear rhabdoid inclusions, a mesenchymal and epithelial immunohistochemical profile, and 22q deletions with inactivation of the INI1/hSNF5 gene. Although they usually occur in young children, AT/RTs are being recognized in adults with increasing frequency. We report the cytologic features of an AT/RT from the cerebellum of a 45‐year‐old man and discuss the differential diagnosis in adults. Diagn. Cytopathol. 2004;31:60–63. © 2004 Wiley‐Liss, Inc.
Metastatic bronchioloalveolar carcinoma presenting as a solitary thyroid nodule: Report of a case with fine‐needle aspiration cytopathology
Authors: Parwani Anil V. , Erozan Yener S. , Ali Syed Z.
Published: June 2004

Although cancers metastatic to the thyroid are frequently mentioned in autopsy studies, such a finding is quite rare in routine clinical practice. Metastatic non‐small‐cell carcinomas to the thyroid may present a diagnostic dilemma, particularly when they share morphological similarities with primary thyroid tumors. Herein, we report a case of metastatic bronchioloalveolar carcinoma that presented as an isolated left thyroid nodule in a 68‐year‐old woman. The aspirates were cellular and showed numerous papillary‐like tissue fragments, elongated nuclei with prominent nuclear grooves, frequent mitoses, and psammoma bodies. The latter features raised the possibility of papillary thyroid carcinoma. However, also seen were three‐dimensional tumor nests and acinar‐forming fragments. Immunostains (positive for cytokeratin‐7 and carcinoembryonic antigen and negative for cytokeratin‐20 and thyroglobulin) confirmed the metastatic nature of the carcinoma. In a patient with known primary neoplasm, the differential diagnosis of a thyroid nodule should always include a metastatic lesion along with primary neoplasia. Diagn. Cytopathol. 2004;31:43–47. © 2004 Wiley‐Liss, Inc.
Fine‐needle aspiration cytology of malignant peripheral nerve sheath tumors
Authors: Gupta Kirti , Dey Pranab , Vashisht Rakesh
Published: June 2004

The histopathologic features of malignant peripheral nerve sheath tumors (MPNSTs) have been well described. There have been limited studies on the cytologic features of MPNST. In this present study, we have retrospectively reviewed eight histopathology confirmed cases of MPNST over a 5‐year period. Detailed cytomorphlogical analysis of these cases was carried out individually by two observers. On cytology, these cases were diagnosed as benign spindle‐cell tumor (two), spindle‐cell tumor possibly benign (one), spindle‐cell tumor possibly malignant (one), malignant spindle‐cell tumor (two), spindle‐cell tumor, and neural origin (two). The cardinal cytomorphologic features were loosely cohesive clusters and fascicular arrangement of spindle cells with rounded ends. The kinking of nuclei was not a conspicuous finding. Fibrillary background was noted in two of the cases. Nuclear pleomorphism was ranged from mild to moderate degree. One case exhibited extensive intranuclear pseudoinclusions. Mitotic figures (including atypical forms) were present in almost all the cases. Possibly a constellation of cytologic features such as clusters of short and long fascicles of cells admixed with dissociated spindle cells of round‐ended nuclei and prominent nucleoli on myxoid or fibrillary background and frequent mitosis may be helpful in diagnosis of MPNSTs. The cytomorphologic features along with clinical correlation are necessary to increase the diagnostic accuracy of MPNST on aspiration cytology. Diagn. Cytopathol. 2004;31:1–4. © 2004 Wiley‐Liss, Inc.
Unsuspected systemic amyloidosis diagnosed by fine‐needle aspiration of the salivary gland: Case report
Authors: Giorgadze Tamar , Baloch Zubair W. , Thaler Erica R. , Gupta Prabodh K.
Published: June 2004

Amyloidosis of the head and neck region may represent a local amyloidoma or a manifestation of systemic disease. Involvement of major salivary glands by either primary or secondary forms of amyloidosis is very rare. We describe a case of systemic amyloidosis that initially presented as submandibular gland mass and was diagnosed by fine‐needle aspiration (FNA). A 69‐year‐old male presented with submandibular mass. His past medical history was significant for left forearm melanoma that was excised 6 years ago and tricuspid valve endocarditis after valvular replacement 3 months prior to FNA of the submandibular gland. The patient had no symptoms or clinical and laboratory data suggestive of amyloidosis. FNA specimen showed salivary gland tissue and abundant amorphous material, which stained positive for amyloid with Congo red stain and showed typical birefringence when examined by polarized microscopy. Further workup of the patient revealed generalized amyloidosis with multiorgan involvement by the disease. This case demonstrates that FNA can be a useful technique in the diagnosis of unsuspected amyloidosis. Diagn. Cytopathol. 2004;31:57–59. © 2004 Wiley‐Liss, Inc.
Histiocytes containing immunoglobulin crystals in the urine of a patient with IgA κ plasmacytoma of the bladder
Authors: Miller Dylan V. , McClure Rebecca F. , Crawford Barbara G. , Zeldenrust Steven R. , Leibovich Bradley C. , Sebo Thomas J.
Published: June 2004

Exfoliative cytology specimens from patients with plasma cell dyscrasias are rarely diagnostic, though there are reports of neoplastic plasma cells observed in pleural fluid and urine. Immunoglobulin concretions or crystals associated with neoplastic plasma cell populations have been well described. These crystals may be found within plasma cell nuclei or cytoplasm, extracellularly, or within cells of histiocytic lineage where they are presumably derived by phagocytosis. To the best of our knowledge, this is the first report of immunoglobulin crystals within histiocytes in the urine of a patient with plasmacytoma. A 61‐year‐old male underwent routine cystoscopy and urine collection to evaluate hematuria. The bladder biopsy demonstrated IgA κ‐producing plasmacytoma. Urine cytopsin preparations did not contain plasma cells, but there were histiocytic cells with degenerative nuclei and eccentrically located cytoplasmic spherical refractile hyaline crystals thought to be immunoglobulin crystals. This was supported by immunocytochemical staining. Diagn. Cytopathol. 2004;31:48–51. © 2004 Wiley‐Liss, Inc.
Zebrafish neuropilins are differentially expressed and interact with vascular endothelial growth factor during embryonic vascular development
Authors: Martyn Ulrike , Schulte‐Merker Stefan
Published: June 2004

Neuropilin1 (Nrp1) and Neuropilin2 (Nrp2) are nonkinase vascular endothelial growth factor receptors (VEGFR) identified in several vertebrates, which function as coreceptors for the receptor tyrosine kinases VEGFR1 and VEGFR2. We identified four zebrafish nrp genes, nrp1a, nrp1b, nrp2a, and nrp2b, and characterized their function in vascular development. We show that all nrp genes display distinct expression patterns and that nrp1a and nrp1b are expressed in the dorsal aorta, while nrp2a and nrp2b transcripts could be detected in the region of the posterior cardinal vein. Knockdown of nrp1a, nrp1b, and nrp2a resulted in improper arteriovenous connections and irregular intersegmental vessel patterning, indicating that these Nrps function in the same process. Nrp2b knockdown also caused vessel malformations and a pericardial defect. In addition, we provide evidence that the newly identified Nrps synergistically interact with VEGF in vivo. Taken together, our results show that, in zebrafish, all four neuropilins are involved in VEGF‐mediated vessel development. Developmental Dynamics 231:33–42, 2004. © 2004 Wiley‐Liss, Inc.
Bmp7 mediates early signaling events during induction of chick epidermal organs
Authors: Harris Matthew P. , Linkhart Barbara L. , Fallon John F.
Published: June 2004

The induction and specification of a large number of vertebrate organs require reciprocal signaling between an epithelium and subjacent mesenchyme. In the formation of integumentary organs, the initial inductive signaling events leading to the formation of the organ primordia stem from the mesenchyme. However, the epithelium must have the capacity to respond to these signals. We demonstrate that bone morphogenetic protein 7 (Bmp7) is an early molecular marker for epidermal organ development during development of feathers and scales of the chick. Bmp7 is expressed broadly in the preplacode epidermis and subsequently becomes localized to the forming placodes of feathers and scales. An examination of Bmp7 expression in the scaleless mutant chicken integument indicates that Bmp7 expression in the epidermis is associated with the ability to form epidermal organs. We show that BMP7 function is necessary for the formation of epidermal placodes in both feather and scale forming epidermis. In addition, precocious expression of Bmp7 in the metatarsal epidermis of the Silkie mutant or treatment of the metatarsus with ectopic BMP7 protein results in feather development from scale forming integument. From these data, we propose that Bmp7 is necessary and sufficient, in a developmental context, to mediate the competence of an epithelium to respond to inductive signals from the underlying mesenchyme to form epidermal organs in the chick. We propose that regulation of Bmp7 in localized areas of the embryonic epidermis facilitates the development of regional formation of integumentary organs. Developmental Dynamics 231:22–32, 2004. © 2004 Wiley‐Liss, Inc.
Expression of VE‐cadherin in zebrafish embryos: A new tool to evaluate vascular development
Authors: Larson Jon D. , Wadman Shannon A. , Chen Eleanor , Kerley Lesa , Clark Karl J. , Eide Mark , Lippert Sarah , Nasevicius Aidas , Ekker Stephen C. , Hackett Perry B. , Essner Jeffrey J.
Published: June 2004

We have identified the zebrafish homologue of VE‐cadherin and documented its expression in the developing vascular system. The zebrafish VE‐cadherin gene is specifically expressed in the vascular endothelial cell lineage beginning with the differentiation and migration of angioblasts and persists throughout vasculogenesis, angiogenesis, and endocardium development. Staining zebrafish embryos by whole‐mount in situ hybridization with the VE‐cadherin probe provides a method to screen embryos for vascular defects. To illustrate this utility, we used VE‐cadherin expression to demonstrate a conservation of vascular endothelial growth factor‐A (VEGF‐A) function. The morpholino antisense oligonucleotide knockdown of VEGF‐A function in zebrafish embryos results in a loss of angiogenic blood vessels, as indicated by the lack of VE‐cadherin expression in the intersegmental vasculature. This loss can be restored in embryos supplemented with either zebrafish or human VEGF‐A, the latter indicating that genes crucial to angiogenesis have highly conserved functional activities in vertebrates. Developmental Dynamics 231:204–213, 2004. © 2004 Wiley‐Liss, Inc.