bluuebunny/crossref_metadata_2025 huggingface dataset:
Differential depression of inhibitory synaptic responses in feedforward and feedback circuits between different areas of mouse visual cortex
Authors: Dong Hongwei , Shao Zhenwei , Nerbonne Jeanne M. , Burkhalter Andreas
Published: June 2004

Recordings of synaptic responses of pyramidal neurons to feedback (FB) inputs from higher to lower areas of visual cortex show that excitatory synaptic responses are only weakly opposed by disynaptic inhibition. Whether weak inhibition is preserved at high frequencies remains unknown. Whole‐cell recordings were performed in pyramidal cells of mouse visual cortex to study the frequency dependence of excitatory and inhibitory postsynaptic currents (EPSCs, IPSCs) elicited by feedforward (FF) input from the primary visual cortex (V1) to the higher lateromedial area (LM) and by FB input from the LM to V1. EPSCs showed similar frequency dependencies in FF and FB pathways; the amplitudes decreased during stimulus trains, and the depression was larger at higher frequencies. IPSCs decreased during repetitive stimulation, and the depression increased at higher frequencies. At >20 Hz, the depression of IPSCs in the FB pathway was greater than in the FF pathway. Thus, unlike FF circuits, FB circuits provide balanced excitatory and inhibitory inputs across a wide range of frequencies. This property was shown to be critically important in cortical circuits that modulate the gain of pyramidal cell firing (Chance et al. [2002] Neuron 35:773–782). J. Comp. Neurol. 475:361–373, 2004. © 2004 Wiley‐Liss, Inc.
F‐actin at identified synapses in the mushroom body neuropil of the insect brain
Authors: Frambach Ina , Rössler Wolfgang , Winkler Margret , Schürmann Friedrich‐Wilhelm
Published: June 2004

The distribution of f‐actin stained by fluorescent phalloidin was investigated in the brain of several insect species, with a special focus on the mushroom body. For localizing f‐actin in identified neurons and at synapses, additional staining with fluorescent dextrans and anti‐synapsin I immunostaining was employed. Intense f‐actin staining was consistently found in synaptic complexes of the mushroom body calyces (calycal microglomeruli [MG]). These MG contain a central core of presynaptic boutons, predominantly belonging to deutocerebral cholinergic excitatory projection neurons, which are surrounded by a shell of numerous Kenyon cell (KC) dendritic tips. In the cricket Gryllus bimaculatus, high‐resolution confocal laser scanning imaging revealed colocalization of f‐actin with KC dendritic spine parts within MG. Although presynaptic boutons appear to be mainly devoid of f‐actin‐phalloidin fluorescence, there appears to be an accumulation of f‐actin in KC dendritic spines synaptically contacting the boutons. Electron microscopy of boutons and dextran‐stained KC dendrites revealed their pre‐ and postsynaptic sites, with KCs being strictly postsynaptic elements. Their subsynaptic membrane appositions are considered to be associated with f‐actin. Focal accumulation of f‐actin in the dendritic tips of KCs was found to be a general feature of MG, with either spheroidal or indented boutons of different sizes, as encountered in the mushroom bodies of the cricket, honey bee, ant, and fruit fly. The structural similarities of calycal MG and f‐actin accumulation in KC dendrites with cerebellar microglomeruli are considered comparatively. The accumulation of f‐actin in KC dendrites is discussed in view of mushroom body plasticity and its potential role in learning and memory formation. J. Comp. Neurol. 475:303–314, 2004. © 2004 Wiley‐Liss, Inc.
Expression and putative role of lactoseries carbohydrates present on NCAM in the rat primary olfactory pathway
Authors: Storan Melonie Joanne , Magnaldo Thierry , Biol‐N'Garagba Marie‐Claire , Zick Yehiel , Key Brian
Published: June 2004

Primary olfactory neurons project axons from the olfactory neuroepithelium lining the nasal cavity to the olfactory bulb in the brain. These axons grow within large mixed bundles in the olfactory nerve and then sort out into homotypic fascicles in the nerve fiber layer of the olfactory bulb before terminating in topographically fixed glomeruli. Carbohydrates expressed on the cell surface have been implicated in axon sorting within the nerve fiber layer. We have identified two novel subpopulations of primary olfactory neurons that express distinct α‐extended lactoseries carbohydrates recognised by monoclonal antibodies LA4 and KH10. Both carbohydrate epitopes are present on novel glycoforms of the neural cell adhesion molecule, which we have named NOC‐7 and NOC‐8. Primary axon fasciculation is disrupted in vitro when interactions between these cell surface lactoseries carbohydrates and their endogenous binding molecules are inhibited by the LA4 and KH10 antibodies or lactosamine sugars. We report the expression of multiple members of the lactoseries binding galectin family in the primary olfactory system. In particular, galectin‐3 is expressed by ensheathing cells surrounding nerve fascicles in the submucosa and nerve fiber layer, where it may mediate cross‐linking of axons. Galectin‐4, ‐7, and ‐8 are expressed by the primary olfactory axons as they grow from the nasal cavity to the olfactory bulb. A putative role for NOC‐7 and NOC‐8 in axon fasciculation and the expression of multiple galectins in the developing olfactory nerve suggest that these molecules may be involved in the formation of this pathway, particularly in the sorting of axons as they converge towards their target. J. Comp. Neurol. 475:289–302, 2004. © 2004 Wiley‐Liss, Inc.
Histaminergic neurons in the central and peripheral nervous system of gastropods (Helix, Lymnaea): An immunocytochemical, biochemical, and electrophysiological approach
Authors: Hegedűs Endre , Kaslin Jan , Hiripi László , Kiss Tibor , Panula Pertti , Elekes Károly
Published: June 2004

Distribution, chemical‐neuroanatomy, concentration, and uptake‐release properties of histamine (HA)‐containing neurons and the possible physiological effects of HA in the central and peripheral nervous system of the pulmonate snails,Helix pomatiaandLymnaea stagnalis, are described. In the CNS of both species, the distribution pattern of HA‐immunoreactive (HA‐IR) neurons was similar. In both species the majority were located in the buccal, cerebral, and pedal ganglia. InHelix, ∼400 HA‐IR neurons were seen, whereas inLymnaea∼130 labeled cells were visualized. The neuropils, connectives, commissures, several peripheral nerves, and a part of the peripheral tissues (lip and foot of both species and the upper tentacles ofHelix) were innervated by HA‐IR elements. Numerous sensory cells were found in the tentacles, lip, and statocysts. The HA concentration values assayed by HPLC ranged from 4.8 to 47.4 pmol/mg in the different central ganglia ofHelix, and from 4.3 to 18.6 pmol/mg inLymnaeaCNS, whereas the peripheral tissues contained 0.33–1 pmol/mg HA inHelixand 0.26–0.46 pmol/mg inLymnaea. In theLymnaeaCNS, a high‐affinity (37.6 μM), single component3H‐HA uptake system was demonstrated.3H‐HA release evoked by either electrical stimulation or 100 mM K+could be prevented in Ca2+‐free physiological solution. Voltage‐clamp experiments indicated specific changes caused by HA in the membrane conductance of identified central neurons ofHelixandLymnaea. Exogenously applied 10‐5M HA resulted in the acceleration of locomotion (gliding by foot cilia) ofLymnaea. The findings suggest an important signaling role of HA, described here for the first time, in the nervous system of higher‐order, pulmonate, gastropods, involving efferent, integrative, and sensory functions. The data can also be applied as a background for further specification of HA in the regulation of different behaviors in these species. J. Comp. Neurol. 475:391–405, 2004. © 2004 Wiley‐Liss, Inc.
Quantitative analysis of olfactory receptor neuron projections in the antennal lobe of the malaria mosquito, Anopheles gambiae
Authors: Anton Sylvia , Rospars Jean‐Pierre
Published: June 2004

Mosquitoes are highly dependent on the olfactory sense to find their hosts. How olfactory information concerning host odors is represented and processed in the brain to elicit olfactory guided behavior is not known. We present an exploratory analysis of central projections of olfactory receptor neurons originating from antennal and maxillary palp sensilla known to be involved in the detection of host odors in the malaria mosquito, Anopheles gambiae. We developed computational neuroanatomic methods to determine quantitatively the positions of olfactory receptor neuron terminal arborizations and compare them between brains. These quantitative analyses suggested the existence of five nonoverlapping projection zones within the antennal lobe, with one zone receiving exclusive input from maxillary palp sensilla and two zones each receiving exclusive input from trichoid or grooved‐peg antennal sensilla. Projection patterns were not found to depend significantly on the odorants used during the staining procedure. The separate zones receiving input from different sensillum types seemed to represent a functional segregation because olfactory receptor neurons present in the different sensilla differed in their response profiles. J. Comp. Neurol. 475:315–326, 2004. © 2004 Wiley‐Liss, Inc.
Differences in projection patterns between large and small corticothalamic terminals
Authors: Van Horn Susan C. , Sherman S. Murray
Published: June 2004

We injected tracer into wide regions of visual cortex in the cat to produce retrograde and orthograde labeling in the thalamus, chiefly in the lateral geniculate nucleus and lateral posterior–pulvinar complex (LP‐Pulvinar). We used the electron microscope to measure the sizes of orthogradely labeled terminals in thalamus and used these measurements to help determine whether the terminals were “RL” (large, presumed excitatory) or “RS” (small, presumed excitatory). We also distinguished reciprocal regions, which were zones of corticothalamic feedback defined by the presence of many retrogradely labeled cell bodies and orthogradely labeled terminals, from nonreciprocal regions, which were zones of feedforward corticothalamic projections defined by the presence of orthogradely labeled terminals alone. The lateral geniculate nucleus, a reciprocal region, had retrogradely labeled cell bodies as well as labeled RS terminals. Likewise, reciprocal regions in LP‐Pulvinar were dominated by labeled RS terminals. In contrast, nonreciprocal regions were dominated by labeled RL terminals. Based on other evidence of corticothalamic projections that RL and RS terminals derive, respectively, from layer 5 and layer 6, we suggest the same relationship here, leading to the conclusion that the corticothalamic input from layer 6 is largely feedback, whereas that from layer 5 is largely feedforward. This finding lends credence to a recent hypothesis that layer 5 corticothalamic axons represent the afferent limb of a cortico‐thalamo‐cortical pathway that is critical for corticocortical communication. J. Comp. Neurol. 475:406–415, 2004. © 2004 Wiley‐Liss, Inc.
Oscillatory calcium responses mediated by P2Y2 purinergic receptors in terminal Schwann cells of longitudinal lanceolate endings isolated from rat vibrissae
Authors: Takahashi‐Iwanaga Hiromi , Habara Yoshiaki
Published: June 2004

The longitudinal lanceolate endings are mechanoreceptors that detect hair movement. We have previously shown that terminal Schwann cells, glial elements of the sensory devices, respond to an application of the sensory modulator adenosine 5′‐triphosphate (ATP) by an elevation in the intracellular Ca2+ concentration ([Ca2+]i), suggesting a regulatory role for these cells in the cutaneous sensation. To define the spatiotemporal dynamics of the cell signaling and the pharmacological properties of the receptors responsible, arrays of the lanceolates were enzymatically isolated from the rat vibrissal follicle and subjected to [Ca2+]i image recording by time‐lapse confocal microscopy during bath application of ATP analogues. The terminal Schwann cells formed extensive networks, connecting with one another by their lamellar processes associated with lanceolate axon endings. Stimulation of the cells with 100 μM ATP evoked [Ca2+]i waves propagating along the cell processes. In each Schwann lamella, the initial wave evoked by a given trial of the stimulant arose from a specific locus within the cell process, whereas subsequent waves were sometimes observed to travel from its proximal portion. This implies a subcellular compartmentalization that may enable each Schwann lamella to modulate the activity of its accompanying lanceolate terminal through its own Ca2+ signal as well as to regulate neighboring lanceolates through interlamellar signal propagation. Pharmacological experiments have shown that the Schwann cell responses are mediated by the P2Y2 receptor, which has recently been reported to couple to multiple effector molecules in addition to stimulating the phosphoinositide signaling pathway involved in various glia–neuron interactions. J. Comp. Neurol. 475:416–425, 2004. © 2004 Wiley‐Liss, Inc.
Solid‐ and Solution‐Phase Synthesis of a Library of Mixed‐Metal Complexes
Authors: Heinze Katja , Bueno Toro Juan D.
Published: June 2004

A solid‐phase synthesis protocol has been developed for the stepwise assembly of mixed‐metal dinuclear complexes built from chromium, molybdenum and tungsten and a directional bridging ligand. Complexes with all nine possible metal combinations have been prepared on polystyrene/divinylbenzene copolymer employing a metal‐complex‐compatible silyl ether linker. Release of the metal complexes from the polymeric support is accomplished by fluoridolysis under mild conditions. The metal sequence in these complexes is precisely determined by the reaction sequence and is retained under the applied reaction conditions as shown by IR, NMR and UV/Vis spectroscopic analysis of the cleaved soluble products. Additionally, the same complex library has been prepared by conventional solution‐phase synthesis to allow evaluation of the advantages and disadvantages of the solid‐phase synthesis method. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Tissue engineering of cartilage with the use of chitosan‐gelatin complex scaffolds
Authors: Xia Wanyao , Liu Wei , Cui Lei , Liu Yuanchun , Zhong Wei , Liu Deli , Wu Juanjuan , Chua Kienhui , Cao Yilin
Published: June 2004

Chitosan has been shown to be a promising scaffold for various applications in tissue engineering. In this study, a chitosan‐gelatin complex was fabricated as a scaffold by a freezing and lyophilizing technique. Chitosan's structure and characteristics are similar to those of glycosaminoglycan (GAG) and its analogs, and possesses various biological activities, whereas gelatin can serve as a substrate for cell adhesion, differentiation, and proliferation. With the use of autologous chondrocytes isolated from pig's auricular cartilage and seeded onto the chitosan‐gelatin scaffold, elastic cartilages have been successfully engineered at the porcine abdomen subcutaneous tissue. After 16 weeks of implantation, the engineered elastic cartilages have acquired not only normal histological and biochemical, but also mechanical properties. The tissue sections of the engineered elastic cartilages showed that the chondrocytes were enclosed in the lacuna, similar to that of native cartilage. The presence of elastic fibers in the engineered cartilages was also demonstrated by Vehoeff's staining, and immunohistochemical staining confirmed the presence of type II collagen in the engineered cartilages. Quantitatively, the GAG in the engineered cartilages reached 90% of the concentration in native auricular cartilage. Furthermore, biomechanical analysis demonstrated that the extrinsic stiffness of the engineered cartilages reached 85% of the level in native auricular cartilage when it was harvested at 16 weeks. Thus, this study demonstrated that the chitosan‐gelatin complex may serve as a suitable scaffold for cartilage tissue engineering. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 71B: 373–380, 2004
Effect of sandblasting on the long‐term performance of dental ceramics
Authors: Zhang Yu , Lawn Brian R. , Rekow E. Dianne , Thompson Van P.
Published: June 2004

A study has been made of the effects of sandblasting on the strength of Y‐TZP and alumina ceramic layers joined to polymeric substrates and loaded at the top surfaces by a spherical indenter, in simulation of occlusal contact in ceramic crowns on tooth dentin. The sandblast treatment is applied to the ceramic bottom surface before bonding to the substrate, as in common dental practice. Specimens with polished surfaces are used as a control. Tests are conducted with monotonically increasing (dynamic) and sinusoidal (cyclic) loading on the spherical indenter, up to the point of initiation of a radial fracture at the ceramic bottom surface immediately below the contact. For the polished specimens, data from the dynamic and cyclic tests overlap, consistent with a dominant slow crack growth mode of fatigue. Strengths of sandblasted specimens show significant reductions in both dynamic and cyclic tests, indicative of larger starting flaws. However, the shift is considerably greater in the cyclic data, suggesting some mechanically assisted growth of the sandblast flaws. These results have implications in the context of lifetimes of dental crowns. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 71B: 381–386, 2004
Cyberterrorism: Are you at risk?
Authors: Singleton Tommie , Singleton Aaron
Published: June 2004

Your company could be a victim of malicious online blackmail—or worse. The perpetrators can be motivated by greed, the desire for revenge, a criminal mind, or a political agenda. The authors reveal which companies are at highest risk, what kinds of attacks are likely, and what companies can do to protect themselves. © 2004 Wiley Periodicals, Inc.
How to pick technology stocks today
Authors: Tokic Damir
Published: June 2004

Technology stocks have lost about 75 percent of their value since the dot‐com bubble burst. Everyone believes technology will continue to play a role in this country's long‐term growth. But how can you find technology stocks that are still worth your investment dollars? The author gives some guidelines that every investor should heed. © 2004 Wiley Periodicals, Inc.
SOA compliance: Will IT sabotage your efforts?
Authors: Cannon David M. , Growe Glenn A.
Published: June 2004

Your IT department's actions are crucial to meeting the new demands of the Sarbanes‐Oxley Act (SOA). But IT people often don't recognize their critical role in implementing financial controls, warn the authors. To make matters worse, you may have additional problems: incorrect or missing systems documentation, not including IT in SOA discussions, and IT attitudes or knowledge gaps that hinder your SOA compliance. So how can you overcome these worrying difficulties? © 2004 Wiley Periodicals, Inc.
Moving from business strategy to IT action
Authors: Benson Robert , Bugnitz Tom , Walton William
Published: June 2004

Where and when should you spend scarce IT dollars? Many CEOs don't want to get bogged down in technology details. But they sure do want to get the most bang for their IT buck. How do you make the right decisions for a better bottom line? © 2004 Wiley Periodicals, Inc.
Need to justify IT security? Measure your risk!
Authors: Iijima Timothy , Curtis Jeffrey
Published: June 2004

Most companies realize that IT‐related business risk is substantial. But few rigorously analyze and quantify that risk. So it's tough to justify a given expense for IT security. The authors show how to measure that risk—and decide if your security actions are adequate. © 2004 Wiley Periodicals, Inc.
The danger of underfunded pensions: What to do about it
Authors: Sylvestre Jeanne , Prescott Gregory L.
Published: June 2004

Nearly two‐thirds of corporate pension plan assets were invested in the stock market when stocks plunged recently. That caused the average S&P 500 company pension plan—which was 128 percent funded—to be only 81 percent funded by the end of 2003. Surprisingly, many executives underestimate the dangers. The authors discuss the magnitude of the problem and offer a sensible action plan. © 2004 Wiley Periodicals, Inc.
MD&A: Latest guidelines force even more disclosure
Authors: Hambleton Wendy , Rouse Robert W. , Weirich Thomas R.
Published: June 2004

The SEC's latest guidelines for MD&A (management's discussion and analysis) reporting will have a significant impact on future disclosures, say the authors. They explain why companies need to pay serious attention. © 2004 Wiley Periodicals, Inc.
Security regional bank: Implementing a balanced scorecard using the business modeling approach
Authors: Brewer Peter C. , Albright Tom , Davis Stan
Published: June 2004

One of the strengths of the balanced scorecard approach is the ability to link strategic goals with operational performance measures. But many adopters discover that while they understand the conceptual linkage between operational performance measures and strategic goals, they lack a structure to guide their efforts. This article illustrates the use of a technique—loosely based on quality management principles—that permits managers to articulate their strategic vision in the form of a process‐oriented business model. A banking institution is used to illustrate the business modeling approach to balanced scorecard development and implementation. © 2004 Wiley Periodicals, Inc.
Effect of albumin on 14C‐α‐Methyl‐d‐Glucopyranoside uptake in primary cultured renal proximal tubule cells: Involvement of PLC, MAPK, and NF‐κB
Authors: Han Ho Jae , Oh Young Joon , Lee Yun Jung
Published: June 2004

A growing body of evidence implicates albumin has an important regulatory function in renal proximal tubule cells (PTCs). In present study, the effect of bovine serum albumin (BSA) on 14C‐α‐methyl‐d‐glucopyranoside (α‐MG) uptake and its related signal molecules were examined in the primary cultured rabbit renal PTCs. BSA significantly increased uptake of α‐MG, a distinctive proximal tubule marker, as well as expression level of Na+/glucose cotransporters (SGLT1 and SGLT2) proteins. The BSA‐induced increase of α‐MG uptake was completely blocked by actinomycin D and cycloheximide. Neomycin or U 73122 (PLC inhibitors), BAPTA/AM or TMB‐8 (intracellular Ca2+ mobilization inhibitors) completely abolished BSA‐induced increase of α‐MG uptake. BSA significantly increased IPs accumulation, but did not affect Ca2+ uptake. Effect of BSA on α‐MG uptake was blocked by PD 98059, but did not SB 203580. BSA increased phosphorylation of p44/42 mitogen activated protein kinase (MAPK) in a time‐dependent manner. NAC or catalase (antioxidants) significantly blocked BSA‐induced increase of H2O2 formation and α‐MG uptake. BSA activated NF‐κB translocation into nucleus. PDTC, SN50, and TLCK (NF‐κB inhibitors) also completely blocked BSA‐induced increase of α‐MG uptake, NF‐κB p65 and phospho IκB‐α activation. In conclusion, BSA stimulates α‐MG uptake and its action is partially correlated with PLC, MAPK, or NF‐κB signal molecules in primary cultured renal PTCs. © 2005 Wiley‐Liss, Inc.
Pulmonary pneumaticity in the postcranial skeleton of extant Aves: A case study examining Anseriformes
Authors: O'Connor Patrick M.
Published: June 2004

Anseriform birds were surveyed to examine how the degree of postcranial pneumaticity varies in a behaviorally and size‐diverse clade of living birds. This study attempts to extricate the relative effects of phylogeny, body size, and behavioral specializations (e.g., diving, soaring) that have been postulated to influence the extent of postcranial skeletal pneumaticity. One hundred anseriform species were examined as the focal study group. Methods included latex injection of the pulmonary apparatus followed by gross dissection or direct examination of osteological specimens. The Pneumaticity Index (PI) is introduced as a means of quantifying and comparing postcranial pneumaticity in a number of species simultaneously. Phylogenetically independent contrasts (PICs) were used to examine the relationship between body size and the degree of postcranial pneumaticity throughout the clade. There is a high degree of similarity (i.e., clade‐specificity) within most anseriform subgroups. As a whole, Anseriformes demonstrate no significant relationship between relative pneumaticity and body size, as indicated by regression analysis of body mass on PI. It is apparent, however, that many clades of diving ducks do exhibit lower PIs than their nondiving relatives. By exclusion of diving taxa from analyses, a significant positive slope is observed and the hypothesis of relatively higher pneumaticity in larger‐bodied birds is only weakly supported. However, low correlations indicate that factors other than body size account for much of the variation observed in relative pneumaticity. Pneumaticity profiles were mapped onto existing phylogenetic hypotheses. A reduction in the degree of postcranial pneumaticity occurred independently in at least three anseriform subclades specialized for diving. Finally, enigmatic pneumatic features located in distal forelimb elements of screamers (Anhimidae) result from invasion of bone by a network of subcutaneous air sac diverticula spreading distally along the wings. J. Morphol. 261:141–161, 2004. © 2004 Wiley‐Liss, Inc.
Functional morphology of the middle ear in Chlorotalpa golden moles (mammalia, Chrysochloridae): Predictions from three models
Authors: Mason Matthew J.
Published: June 2004

The ossicular apparatus of golden moles in the genus Chlorotalpa has received comparatively little attention in the literature, although the malleus is known to be intermediate in size between the “unmodified” malleus of Amblysomus and the hypertrophied mallei found in some other golden moles. In the present study, the middle ear structures of three Chlorotalpa species (C. duthieae, C. sclateri, and C. arendsi) are described. Measurements of middle ear structures were applied into three existing models of middle ear function. The predictions from the models suggest that the airborne hearing of Chlorotalpa species is limited to relatively low frequencies, but the impedance transformation by the middle ear apparatus is expected to be reasonably efficient. The sensitivity of the middle ear apparatus to inertial bone conduction is intermediate between that predicted for Amblysomus and that predicted for species with hypertrophied mallei. Hearing in fossorial mammals may be limited by factors other than the middle ear apparatus: the predictions for Chlorotalpa must therefore be treated with caution. However, a consideration of the “intermediate” middle ear morphology of Chlorotalpa species sheds some light on the origin of ossicular hypertrophy in golden moles. The limited enlargement of the malleus seen in Chlorotalpa is expected to have improved seismic sensitivity by bone conduction significantly at low frequencies, while airborne hearing might not have been adversely affected. J. Morphol. 261:162–174, 2004. © 2004 Wiley‐Liss, Inc.
Larynx morphology and sound production in three species of Testudinidae
Authors: Sacchi Roberto , Galeotti Paolo , Fasola Mauro , Gerzeli Giuseppe
Published: June 2004

Although the ability to vocalize is widespread among tortoises, the mechanisms of sound production in chelonians remain undescribed. In this study, we analyze the morphology and histology of the larynx of three species of Testudinidae (Testudo hermanni, T. graeca, and T. marginata) in order to ascertain the presence of vibrating acoustic structure, and based on our findings we propose a general model for phonation in tortoises. The structure of the larynx of the three tortoises analyzed is simple: three cartilages (the cricoid and two arytenoids) form the skeleton of the larynx, while two pairs of muscles (the dilators and constrictors) control the widening and closing of the glottis. The larynx is supported in the oral cavity by the hyoid cartilage, which in tortoises assumes the same functions of the thyroid cartilage of mammals. Two bands of elastic fibers are inserted in the lateral walls of the larynx just upstream of the glottis, and can be stretched away from the hyoid by the movements of the arytenoids. Their position and structure suggest that these bands are capable of vibrating during exhalation, and therefore may be considered vocal cords. The cricoid of T. marginata and T. graeca hold two diverticula, not previously reported, which might function as a low‐frequency resonating chamber, improving the harmonic structure of tortoise calls. The structure of the larynx is compared with that of other vertebrates and the relationships between morphology and phonation are discussed. This is the first detailed description of anatomical structures possibly devoted to vocalization in chelonians. J. Morphol. 261:175–183, 2004. © 2004 Wiley‐Liss, Inc.
Glycoconjugate localization in larval and adult skin of the bullfrog, Rana catesbeiana: A lectin histochemical study
Authors: Kaltenbach Jane C. , Faszewski Ellen E. , Nytch Karen E. , Potter Christine H. , Shanthakumar Narmatha , Fakin Alina
Published: June 2004

This study investigates whether or not the distribution of specific glycoconjugates within the skin is related to the regulation of water balance in the aquatic larvae and semiaquatic adults of the bullfrog, Rana catesbeiana. A lectin histochemical study was carried out on paraffin sections of dorsal and ventral skin from tadpoles in representative stages as well as from adult frogs. Sections were stained with the following horseradish peroxidase (HRP)‐conjugated lectins, which bind to specific terminal sugar residues of glycoconjugates: UEA 1 for α‐L‐fucose, SBA for N‐acetyl‐D‐galactosamine, WGA for N‐acetyl‐B‐D‐glucosamine, and PNA for β‐galactose. Results indicate that lectins serve as markers for specific skin components (e.g., a second ground substance layer within the dermis was revealed by positive UEA 1 staining). Moreover, each lectin has a specific binding pattern that is similar in dorsal and ventral skin; the larval patterns change as the skin undergoes extensive histological and physiological remodeling during metamorphic climax. These findings enhance our understanding of glycoconjugates and their relationship to skin structure and function—in particular, to the regulation of water balance in R. catesbeiana. J. Morphol. 261:184–195, 2004. © 2004 Wiley‐Liss, Inc.
Spermatozoa of Pseudinae (Amphibia, Anura, Hylidae), with a test of the hypothesis that sperm ultrastructure correlates with reproductive modes in anurans
Authors: Garda Adrian A. , Costa Gabriel C. , Colli Guarino R. , Báo Sônia N.
Published: June 2004

We describe, for the first time, the sperm ultrastructure of the two genera of Pseudinae. Based on sperm ultrastructure, the five species herein examined can be separated into three groups: one containing Pseudis paradoxa, P. bolbodactyla, and P. tocantins, the second containing P. minuta, and the third containing Lysapsus laevis. The midpiece is similar in all species and auxiliary fibers and the undulating membrane are absent. In Pseudis a subacrosomal cone and a multilaminar structure (P. minuta) or a granular material (P. paradoxa group) are seen above the nucleus. Lysapsus laevis has only remnants of the subacrosomal cone. All species have peripheral fibers associated with the outer doublets of the axoneme. We tested the hypothesis of correlation between the presence of an undulating membrane and fertilization environments in anurans using a concentrated changes test (CCT) based on the Hay et al. (Mol Biol Evol 1995;12:928–937) hypothesis of phylogenetic relationships among anuran families. Only a subset of the resolved topologies derived from the Hay et al. (1995) cladogram, where Ranoidea is the sister‐group of Sooglossidae, produced significant probabilities of the CCT. Therefore, support for the correlation between sperm ultrastructure and fertilization environments in anurans is, at best, equivocal. J. Morphol. 261:196–205, 2004. © 2004 Wiley‐Liss, Inc.
Feeding mechanisms in two treefrogs, Hyla nana and Scinax nasicus (Anura: Hylidae)
Authors: Vera Candioti M.F. , Lavilla E.O. , Echeverría D.D.
Published: June 2004

After the description of the chondrocranium, hyobranchial apparatus, associated musculature, buccal apparatus, buccopharyngeal cavity, digestive tract, and gut contents, it was possible to define the feeding modes of Scinax nasicus and Hyla nana tadpoles (Gosner Stages 31–36). Scinax nasicus larvae are “typical” microphagous tadpoles, with keratodonts and robust rostrodonts appropriate for rasping surfaces and mincing of food particles; the buccopharyngeal cavity is equipped with filtering structures and has a conspicuous glandular zone and a highly developed branchial basket. In contrast, H. nana tadpoles have a modified buccal apparatus; the reduction of the buccopharyngeal and branchial basket structures, together with the high lever–arm ratio and the great development of the depressor muscles of the buccal floor are indicative of macrophagous feeding. J. Morphol. 261:206–224, 2004. © 2004 Wiley‐Liss, Inc.
Myo‐anatomy of juvenile and adult loxosomatid Entoprocta and the use of muscular body plans for phylogenetic inferences
Authors: Wanninger Andreas
Published: June 2004

The anatomy of the muscle bauplan in juvenile buds and adult specimens of the solitary loxosomatid entoprocts Loxosoma nielseni and L. annelidicola was studied by means of fluorescence staining of F‐actin and confocal laser scanning microscopy. Although the general myo‐anatomy of the body wall shows numerous similarities, both species express significant variations in the arrangement of their pedal muscles. In addition, L. annelidicola alone shows a distinct pair of rectum retractor muscles. Circular muscles are absent in the entire body wall of both species, as well as in previously investigated colonial taxa, which is therefore regarded as basal for Entoprocta. This is in striking contrast to the conditions found in other spiralian or lophotrochozoan taxa. The simple morphology of entoproct tentacle muscles, however, coincides with the phoronid‐ectoproct condition and may be due to functional constraints of a simple filter‐feeding system. This work shows that variations in the muscular anatomy provide useful characters for systematic analyses on species as well as phylum level and thus allow significant insight regarding metazoan body plan evolution. The phenomenon of phenotypic plasticity and its consequences for phylogenetic interpretations, however, must be carefully considered. J Morphol. 261:249–257, 2004. © 2004 Wiley‐Liss, Inc.
Similar HIV‐1 evolution and immunological responses at 10 years despite several therapeutic strategies and host HLA Types
Authors: Arnedo‐Valero Mireia , Plana Montserrat , Mas Antonio , Guilà Meritxell , Gil Cristina , Castro Pedro , Garcia Felipe , Domingo Esteban , Gatell Josep Ma , Pumarola Tomàs
Published: June 2004

Two sexual partners infected with related HIV‐1 viruses and enrolled in different therapeutic strategies including structured treatment interruptions (STI) provided us an opportunity to compare long term (10 years) viral genetic evolution for closely related isolates in different hosts. HLA loci were molecularly typed and different genetic markers were studied. The viral genetic evolution was studied by sequencing pol and env genes. The HIV‐specific CD4+ and CD8+ T cell responses were assessed by the lymphoproliferative response (LPR) and an ELISPOT assay, respectively. HLA class I loci of patients A and B were different and both of them were heterozygous for CCR5Δ32 gene. During the two STI studies, viral load of both patients rebounded after treatment interruption and both developed a transitory strong helper and CTL responses. After definitive interruption of therapy, viral load remained belowx 5,000 copies/ml without therapy during the two years of follow‐up. Two patients infected with related viruses showed a similar dynamics of viral evolution and CD4 T cells, despite hosts having a different HLA type and being treated with several therapeutic protocols, after 10 years of infection. These results suggest that, in this case, an effective immunological response to STI depended more on the virus than on the characteristics of the host. J. Med. Virol. 73:495–501, 2004. © 2004 Wiley‐Liss, Inc.
Precision and stability of hepatitis B virus DNA levels in chronic surface antigen carriers
Authors: Plentz Annelie , Koller Gabriele , Weinberger Klaus M. , Jilg Wolfgang
Published: June 2004

Quantitative determination of hepatitis B virus (HBV) DNA concentration is the most important measure for an estimation of the infectivity of an HBV positive health care worker and the basis for the decision whether he or she is allowed to perform exposure prone procedures. Thus questions are raised on how reliable quantitative HBV DNA assays are, and how stable is the HBV DNA concentration is in a healthy chronic HBV carrier. Therefore, in the present study two commercially available quantitative HBV DNA assays, the Amplicor HBV Monitor and the HBV Test Hybrid Capture II, and an “in house” quantitative HBV TaqMan PCR, analysing 101 sera of HBsAg positive patients for HBV DNA were compared. In addition, HBV DNA concentrations were followed in 14 healthy chronic carriers for up to 6 years. Despite a good overall correlation between the three tests considerable differences were found for the results of individual sera. Fifty‐one percent of sera showed differences within one order of magnitude, 45% differed by a factor above 10 and 4% even by a factor of 100 and higher. The follow‐up of the HBV DNA concentrations in 14 carriers showed in 7 carriers a rather stable course with variations within one order of magnitude, whereas in the other half the DNA concentrations fluctuated by factors between 102 and 106 over the observation period. Thus, viral load determinations in health care workers have to be interpreted with some caution, especially when they are the basis of far‐reaching decisions. J. Med. Virol. 73:522–528, 2004. © 2004 Wiley‐Liss, Inc.
Expression of hepatitis C virus core protein inhibits interferon‐induced nuclear import of STATs
Authors: Melén Krister , Fagerlund Riku , Nyqvist Maria , Keskinen Päivi , Julkunen Ilkka
Published: June 2004

IFN‐α combined with ribavirin is used for the treatment of chronic hepatitis C. However, HCV has mechanisms to resist the antiviral actions of IFN‐α. In order to study the molecular mechanisms of this resistance, the effect of HCV gene expression on IFN‐induced nuclear import of STAT transcription factors and the expression of antiviral MxA protein were studied. In transiently transfected hepatoma cells, HCV core and NS5A proteins clearly inhibited the nuclear import of STAT1 and MxA protein expression (core only), whereas other viral proteins had only a marginal effect. To confirm these observations, human osteosarcoma‐derived cell lines, which inducibly express HCV core protein, the entire structural region (core‐E1‐E2‐p7), the NS3‐4A complex, NS4B, NS5A, or NS5B proteins were also used. IFN‐induced nuclear accumulation of STAT1 was almost completely and STAT2 was partially blocked in cell lines expressing high levels of HCV core protein. Subsequently, in these cells, IFN‐α‐induced MxB protein expression was decreased. Tumor necrosis factor‐α (TNF‐α)‐induced nuclear import of NF‐κB was only weakly or not at all inhibited, suggesting that the nuclear import machinery in general was not impaired. The results demonstrate a novel mechanism by which HCV gene expression may interfere with IFN‐mediated host defence systems. J. Med. Virol. 73:536–547, 2004. © 2004 Wiley‐Liss, Inc.
Failure to diagnose recent hepatitis C virus infections in London injecting drug users
Authors: Aarons Emma , Grant Paul , Soldan Kate , Luton Pete , Tang Julian , Tedder Richard
Published: June 2004

Hepatitis C virus (HCV) infection results in chronic liver disease in a substantial proportion of those infected. Most new cases of HCV infection in the UK are associated with intravenous drug use. It is important to identify these infections because of the implications for the future health of the individuals concerned and for the control of further spread of infection. However, as hepatitis C infection is characterised by a relatively long asymptomatic period of seronegative viraemia, a laboratory diagnostic protocol that does not test HCV seronegative samples for the presence of HCV RNA may wrongly designate HCV viraemic seronegative individuals as uninfected. Amongst 424 injecting drug users whose serum was sent to our diagnostic laboratory for “HCV screening” over a 14‐month period, the prevalence of HCV seropositivity was 48.4%. We retrospectively identified seven individuals for whom there was evidence of recent acquisition of HCV infection. Three of these infections were identified using our routine diagnostic protocol: testing for the presence of HCV‐specific antibody and performing HCV RNA testing only on seropositive and seroindeterminate specimens. However, four cases were only identified by HCV RNA testing of HCV seronegative serum. On the basis of these observations, we estimate the incidence of HCV infection amongst London injecting drug users as being 14.3 per 100 person‐years. We advocate that all HCV seronegative blood samples obtained from injecting drug users should be tested for the presence of HCV RNA, and suggest that this could be done efficiently by nucleic acid testing the specimens in small pools. J. Med. Virol. 73:548–553, 2004. © 2004 Wiley‐Liss, Inc.
Prevalence of antibodies to hepatitis E virus among Japanese blood donors: Identification of three blood donors infected with a genotype 3 hepatitis E virus
Authors: Fukuda Satoko , Sunaga Junko , Saito Nobuo , Fujimura Kuniko , Itoh Yaeko , Sasaki Masahide , Tsuda Fumio , Takahashi Masaharu , Nishizawa Tsutomu , Okamoto Hiroaki
Published: June 2004

Risk factors for acquiring hepatitis E among individuals in industrialized countries including Japan are not fully understood. We investigated whether Japanese blood donors with or without an elevated alanine aminotransferase (ALT) level are likely to have hepatitis E virus (HEV) infection. Serum samples were collected from 5,343 voluntary blood donors including 1,087 donors with elevated ALT of 61–966 IU/L and 4,256 donors with normal ALT (≤60 IU/L) at two Japanese Red Cross Blood Centers, and were tested for the presence of anti‐HEV IgG by in‐house enzyme‐linked immunosorbent assay (ELISA). Overall, 200 donors (3.7%) were positive for anti‐HEV IgG, including 32 (2.9%) with elevated ALT and 168 (3.9%) with normal ALT. Serum samples with anti‐HEV IgG were further tested for the presence of anti‐HEV IgM by in‐house ELISA and for HEV RNA by reverse transcription (RT)‐polymerase chain reaction (PCR). Three donors with ALT of 966, 62 or 61 IU/L were positive for anti‐HEV IgM and HEV RNA. The HEV isolates obtained from the three viremic donors segregated into genotype 3, were 91.5–93.4% similar to each other in the 412 nucleotide sequence of open reading frame 2, and had the highest identity of 91.5–94.9% with the JRA1 isolate which was recovered from a Japanese patient with sporadic acute hepatitis E who had never been abroad, suggesting that these three HEV isolates are indigenous to Japan. This study suggests that a small but significant proportion of blood donors in Japan with or without elevated ALT are viremic and are potentially able to cause transfusion‐associated hepatitis E. J. Med. Virol. 73:554–561, 2004. © 2004 Wiley‐Liss, Inc.
Detection of ganciclovir resistance after valacyclovir‐prophylaxis in renal transplant recipients with active cytomegalovirus infection
Authors: Alain S. , Hantz S. , Scieux C. , Karras A. , Mazeron M.C. , Szelag J.C. , Imbert B.M. , Fillet A.M. , Gouarin S. , Mengelle C. , de Wilde A. , Cogne N. , Champier G. , Rogez S. , Legendre C. , Denis F.
Published: June 2004

Whether valaciclovir (VCV) prophylaxis could be responsible for ganciclovir (GCV)‐resistance of Human cytomegalovirus (HCMV) in transplantation has never been documented. A multicentric retrospective pilot study was undertaken to detect GCV‐resistance through mutations within the UL97 gene in renal transplant recipients who experienced active HCMV infection and received valacyclovir prophylaxis. Twenty‐three patients who experienced HCMV antigenaemia or DNAemia during or at the end of prophylaxis were included. UL97 genotyping was carried out on peripheral blood samples, using a nested in‐house PCR, which amplified the full‐length UL97 gene. One patient has a resistance‐related mutation (M460I); the major risk factor for emergence of resistance in this patient was the presence of early and persistent antigenaemia. GCV‐resistance during VCV‐prophylaxis was rare after renal transplantation. However, special attention must be paid to patients developing early active HCMV infection under prophylaxis. J. Med. Virol. 73:566–573, 2004. © 2004 Wiley‐Liss, Inc.
Immune responses to Epstein–Barr virus lytic proteins in patients with nasopharyngeal carcinoma
Authors: Liu Mei‐Ying , Huang Yu‐Tzu , Sheen Tzung‐Shiahn , Chen Jen‐Yang , Tsai Ching‐Hwa
Published: June 2004

Immune responses to three Epstein–Barr virus (EBV) lytic proteins, DNase, thymidine kinase (TK), and BMRF‐1 gene products (50/52 kDa diffused early antigen, EA‐D complex) were determined in EBV‐infected control individuals and patients with nasopharyngeal carcinoma (NPC). Immunofluorescence assays (IFA) were used to detect their humoral immune responses using recombinant EBV lytic proteins expressed in a baculovirus system as antigens. Cell proliferation assays were performed to evaluate their cellular immune responses by monitoring 3H‐thymidine incorporation. Seventy patients with NPC and 32 non‐cancer controls were analyzed. The results of IFA showed antibody titers to all three EBV lytic proteins to be higher in the patients with NPC especially for the IgA class. Positivity rates of the three IgA antibodies also were higher in the patients with NPC population. Furthermore, the profiles of the IgA antibodies correlated with those to total early antigens (EA) expressed in the early phase and viral capsid antigen (VCA) expressed in the late phase, of EBV replication. The most interesting finding was that antibody titers to the three EBV lytic proteins were associated significantly with metastases of cervical lymph nodes in patients with NPC. As for cellular immunity to the EA‐D complex and DNase, weak responses were observed in the cell proliferation assays. Peripheral blood cells from most individuals could not be stimulated to proliferate, except for a few patients with NPC whose antibody titers against the EA‐D complex and DNase also were very high. J. Med. Virol. 73:574–582, 2004. © 2004 Wiley‐Liss, Inc.