bluuebunny/crossref_metadata_2025 huggingface dataset:
Aspirin effects on gastric epithelial cell proliferation and cytokine expression
Authors: Pohle Thorsten , Becker Jan C. , Markmann André , Lügering Norbert , Pauels Hans‐Gerd , Konturek Jan W. , Domschke Wolfram
Published: August 2002

Aspirin is known to cause gastric injury and to delay ulcer healing. The effects of aspirin on gastric epithelial cell function are heterogeneous; in contrast to injuring the mucosa, aspirin may also act beneficially by inducing adaptation; a mechanism that is poorly understood. We aimed to document the effects of different doses of aspirin on gastric epithelial cell function defined as proliferation, and secretion as well as mRNA expression of cytokines. Furthermore, we studied the effects of aspirin pretreatment on cytokine secretion as a potential element of gastric adaptation. The proliferative activity of three different gastric epithelial cell lines (AGS, KATO III, RGM‐1) was assessed by 3H‐thymidine incorporation; secretion of growth factors PDGF‐AB and VEGF into culture supernatant was documented by ELISA. mRNA transcripts of both cytokines were quantified by real time RT‐PCR. Low doses of aspirin did not alter the proliferative dynamics in two of the three studied cell lines; high doses abolished proliferation. Secretion of PDGF‐AB and VEGF increased during the first days of low dose apirin exposition; higher concentrations led to a depletion of cytokines after an initial liberation in the case of VEGF, mRNA of which was also dose‐dependently increased by aspirin. Seven‐day pretreatment with low amounts of aspirin did not alter the secretory response of the epithelia caused by higher doses of this drug. The secretion of cytokines and proliferation of gastric epithelial cells are adversely effected by aspirin in a similarly dose‐dependent fashion as the intended effects of this drug on platelet function and pain relief. Microsc. Res. Tech. 53:354–359, 2001. © 2001 Wiley‐Liss, Inc.
Lateral magnocellular nucleus of the anterior neostriatum (LMAN) in the zebra finch: Neuronal connectivity and the emergence of sex differences in cell morphology
Authors: Nixdorf‐Bergweiler Barbara E.
Published: August 2002

The song system of birds provides a model system to study basic mechanisms of neuronal plasticity and development underlying learned behavior. Song learning and production involve discrete sets of interconnected nuclei in the avian brain. One of these nuclei, the lateral magnocellular nucleus of the anterior neostriatum (LMAN), is the output of the so‐called anterior forebrain pathway known to be essential for learning and maintenance of song, both processes depending on auditory feedback. In zebra finches, only males sing and this sexually dimorphic behavior is mirrored by sexual dimorphism in neuronal structure that develops during ontogeny. Female zebra finches are not able to sing and nuclei of the song system are strongly reduced in size or even lacking, when compared to male brains. Only LMAN can be delineated as easily in females as in males. Since female zebra finches, despite being unable to sing, recognize song just as males do and form a memory for song (model acquisition) early in life, LMAN is a putative candidate for song acquisition in both sexes. Therefore, development of LMAN was studied at the cellular and ultrastructural level in both male and female zebra finches. Regressive development of dendritic spines, enlargement of neuronal cell body and nuclei size, as well as changes at the nucleolar level are events all occurring exclusively in males, when song learning progresses. The decline in synapse number and the augmentation in synaptic contact length at synapses in LMAN in males are indicative for synaptic plasticity, whereas in females synapse number and synaptic contact length remain unchanged. Microsc. Res. Tech. 54:335–353, 2001. © 2001 Wiley‐Liss, Inc.
Molecular sexing of monomorphic endangered Ara birds
Authors: Bermúdez‐Humarán Luis Gilberto , García‐García Aracely , Leal‐Garza Carlos Humberto , Riojas‐Valdes Victor Manuel , Jaramillo‐Rangel Gilberto , Montes‐de‐Oca‐Luna Roberto
Published: August 2002

Survival of most endangered birds may depend on breeding programs where sex identification plays an important role. Molecular sexing has shown to be a rapid and safe procedure. In this work we established sex identification of monomorphic endangered Ara birds using a chromosome W‐linked DNA marker, the Chromo‐helicase‐DNA‐Binding 1 (CHD) gene. Most birds have two CHD sex‐linked genes, one W‐linked (CHD‐W) and one Z‐linked (CHD‐Z). These markers were characterized from Ara militaris and gender sex was determined by PCR and restriction analyzes. The procedure here reported was successfully applied to five different species of the genus Ara and confirmed the validity of the technique. To our knowledge, this is the first report of molecular sexing of the Ara species. This molecular sexing is currently been used in breeding programs of Ara birds. J. Exp. Zool. 292:677–680, 2002. © 2002 Wiley‐Liss, Inc.
Metamorphosis of summer flounder, Paralichthys dentatus: Cell proliferation and differentiation of the gastric mucosa and developmental effects of altered thyroidal status
Authors: Soffientino Bruno , Specker Jennifer L.
Published: August 2002

Summer flounder, like most marine fishes studied to date, are stomachless at first feeding, and subsequently acquire gastric function during the process of metamorphosis. Stomach formation is controlled largely by thyroxine (T4). In the present work we sought to understand gastric organogenesis in terms of cell proliferation and its relationship to histological differentiation. The objectives of the study were (1) to obtain a developmental pattern of cell proliferation in the gastric mucosa and to relate that pattern to the progress of gastric differentiation; and (2) to understand the regulatory role of T4 on cell proliferation and histological differentiation by altering the thyroidal status of the developing larvae. We observed that (1) in normally developing larvae, cell proliferation increased by early metamorphic climax (MC), remained high until mid‐MC, and decreased to basal levels by late MC; concomitantly, the gastric glands appeared and differentiated in the fundic mucosa, and were complete by late MC; (2) T4 accelerated the differentiation of gastric glands and mucus neck cells, while inhibiting the concomitant increase in cell proliferation observed in controls; and (3) the goitrogen thiourea inhibited both cell proliferation and gastric differentiation compared to controls. These results indicate that T4 is necessary for the three‐fold increase in cell proliferation that occurs in early metamorphic climax, but that high T4 levels promote differentiation at the expense of proliferation. The observed effects would be consistent with the normal, metamorphosis‐related increase in whole body T4. J. Exp. Zool. 290:31–40, 2001. © 2001 Wiley‐Liss, Inc.
Regulation of male sexual development by Sry and Sox9
Authors: Koopman Peter , Bullejos Monica , Bowles Jo
Published: August 2002

Sry, a gene from the Y chromosome, is known to initiate testis formation and subsequent male differentiation in mammals. A related gene, Sox9, also plays a critical role in testis determination, possibly in all vertebrates. A number of models have been presented regarding the molecular modes of action of these two genes. However, details regarding their regulation, regulatory target genes, and interacting protein factors and co‐factors have not been established with any certainty. In this review, we examine new evidence and re‐examine existing evidence bearing on these issues, in an effort to build up an integrative model of the network of gene activity centred around Sry and Sox9. J. Exp. Zool. 290:463–474, 2001. © 2001 Wiley‐Liss, Inc.
Fluid‐phase endocytosis does not contribute to rapid fluid secretion in the malpighian tubules of the house cricket, Acheta domesticus
Authors: Hazelton S. Renee , Spring Jeffrey H. , Felgenhauer Bruce E.
Published: August 2002

When the Malpighian tubules (Mt) of the house cricket (Acheta domesticus) are treated with dibutyryl adenosine 3′, 5′‐cyclic monophosphate (db‐cAMP; 1 mM), which causes a doubling in secretion rate, more than 50% of the cell volume is occupied by vesicles within 420 sec of exposure. In view of the fact that the increase in vesiculation occurs concomitantly with stimulated fluid transport, we set out to determine whether the vesicles are formed as a result of fluid‐phase endocytosis (pinocytosis) and subsequently used to transport fluid to the lumen as one means of increasing transport rate. We used fluorescent fluid‐phase markers (Lucifer Yellow Carbohydrazide [LYCH] and Alexa 488 hydrazide) and an electron dense marker (cationized ferritin) to elucidate the degree of endocytosis that occurred with db‐cAMP stimulation. We found that, although some fluid is taken into the cells of the mid‐tubule via endocytosis, it does not coincide with the level of vacuolation present in stimulated tubules. The amount of LYCH transported into the primary urine by the db‐cAMP‐stimulated Mt decreased by 40% as compared to the unstimulated transport, and the rate of transport of LYCH was only 30% of the unstimulated tubules. In summary, our findings do not support the theory that the majority of the vesicles or vacuoles comprise intracellular, endocytotic compartments formed via a basolateral endocytotic pathway. We also found no evidence to support the functioning of vesicles or vacuoles as transcellular “shuttling” mechanisms to move fluid from the basal region to the apical membrane and into the lumen. J. Exp. Zool. 292:1–10, 2002. © 2002 Wiley‐Liss, Inc.
Identification and characterization of proteases involved in specific proteolysis of vitellogenin and yolk proteins in salmonids
Authors: Hiramatsu Naoshi , Ichikawa Norimasa , Fukada Haruhisa , Fujita Toshiaki , Sullivan Craig V. , Hara Akihiko
Published: August 2002

A pepstatin A‐sensitive enzyme involved in yolk formation was purified from the masu salmon (Oncorhynchus masou) ovary using in vitro generation of yolk proteins from purified vitellogenin to assay enzymatic activity. Purification of the enzyme involved precipitation of ovarian extracts by water and ammonium sulfate followed by five steps of column chromatography. After SDS‐PAGE and Western blotting, the purified enzyme appeared as a single ∼42 kDa band that was immunoreactive to anti‐human cathepsin D. The course of proteolytic cleavage of the three major yolk proteins (lipovitellin, β′‐component, and phosvitin) in fertilized masu salmon and Sakhalin taimen (Hucho perryi) eggs and embryos was visualized by SDS‐PAGE and Western blotting using specific antisera. Major yolk protein bands appeared in positions corresponding to 92 kDa, 68 kDa, and 22 kDa (lipovitellin‐derived peptides), as well as 17 kDa (β′‐component). During embryo development, the 92 kDa and 22 kDa bands gradually decreased in intensity, becoming undetectable in alevins. The 68 kDa band and a minor 24 kDa band became more intense after the eyed stage. Two additional peptides, corresponding to 40 and 28 kDa, newly appeared in alevins. During embryonic growth, the β′‐component band (17 kDa) persisted and phosvitin appeared to be progressively dephosphorylated. In vitro analysis of lipovitellin proteolysis indicated that the enzyme involved is a Pefabloc SC‐sensitive serine protease. These results demonstrate, for the first time, that a cathepsin D‐like protease and serine proteases play key roles in yolk formation and degradation, respectively, in salmonid fishes. J. Exp. Zool. 292:11–25, 2002. © 2002 Wiley‐Liss, Inc.
Directional sensitivity of wind‐sensitive giant interneurons in the cave cricket Troglophilus neglectus
Authors: Schrader Š. , Horseman G. , Čokl A.
Published: August 2002

Unlike the situation in most cockroach and cricket species studied so far, the wind‐sensitive cerci of the cave cricket Troglophilus neglectus Krauss (Rhaphidophoridae, Orthoptera) are not oriented parallel to the body axis but perpendicular to it. The effects of this difference on the morphology, and directional sensitivity of cercal giant interneurons (GIs), were investigated. In order to test the hypothesis that the 90° change in cercal orientation causes a corresponding shift in directional sensitivity of GIs, their responses in both the horizontal and vertical planes were tested.

One ventral and four dorsal GIs (corresponding to GIs 9‐1a and 9‐2a, 9‐3a, 10‐2a, 10‐3a of gryllid crickets) were identified. The ventral GI 9‐1a of Troglophilus differed somewhat from its cricket homologue in its dendritic arborisation and its directional sensitivity in the horizontal plane. The morphology and horizontal directionality of the dorsal GIs closely resembled that of their counterparts in gryllids. In the vertical plane, the directionality of all GIs tested was similar. They were all excited mainly by wind puffs from the axon‐ipsilateral quadrant. The results suggest that directional sensitivity to air currents in the horizontal plane is maintained despite the altered orientation of the cerci. This is presumably due to compensatory modifications in the directional pReferences of the filiform hairs. J. Exp. Zool. 292:73–81, 2002. © 2002 Wiley‐Liss, Inc.
Acyclic edge colorings of graphs
Authors: Alon Noga , Sudakov Benny , Zaks Ayal
Published: August 2002

A proper coloring of the edges of a graph G is called acyclic if there is no 2‐colored cycle in G. The acyclic edge chromatic number of G, denoted by a′(G), is the least number of colors in an acyclic edge coloring of G. For certain graphs G, a′(G) ≥ Δ(G) + 2 where Δ(G) is the maximum degree in G. It is known that a′(G) ≤ 16 Δ(G) for any graph G. We prove that there exists a constant c such that a′(G) ≤ Δ(G) + 2 for any graph G whose girth is at least cΔ(G) log Δ(G), and conjecture that this upper bound for a′(G) holds for all graphs G. We also show that a′(G) ≤ Δ + 2 for almost all Δ‐regular graphs. © 2001 John Wiley & Sons, Inc. J Graph Theory 37: 157–167, 2001
General properties of some families of graphs defined by systems of equations
Authors: Lazebnik Felix , Woldar Andrew J.
Published: August 2002

In this paper we present a simple method for constructing infinite families of graphs defined by a class of systems of equations over commutative rings. We show that the graphs in all such families possess some general properties including regularity and biregularity, existence of special vertex colorings, and existence of covering maps—hence, embedded spectra—between every two members of the same family. Another general property, recently discovered, is that nearly every graph constructed in this manner edge‐decomposes either the complete, or complete bipartite, graph which it spans. In many instances, specializations of these constructions have proved useful in various graph theory problems, but especially in many extremal problems. A short survey of the related results is included. We also show that the edge‐decomposition property allows one to improve existing lower bounds for some multicolor Ramsey numbers. © 2001 John Wiley & Sons, Inc. J Graph Theory 38: 65–86, 2001
School education and HIV control in sub‐Saharan Africa: from discord to harmony?
Authors: Gregson Simon , Waddell Heather , Chandiwana Stephen
Published: August 2002

HIV is widely regarded as a disease of poverty and ignorance. However, within sub‐Saharan Africa, more developed countries and sub‐populations appear to have higher levels of HIV prevalence. This paper considers the evidence and possible reasons for this, by focusing on the relationships between education and the spread of HIV at the macro and micro levels. It is concluded that more educated populations are initially particularly vulnerable to HIV but are also better equipped to mount effective responses. Expanding provision of and access to secondary education could facilitate HIV control but is severely hampered by the morbidity and mortality effects of HIV epidemics. Efforts to sustain and increase education levels and to reduce HIV infections should therefore be mutually re‐enforcing but will require extensive resources. Copyright © 2001 John Wiley & Sons, Ltd.
Syntheses of 2H‐labelled dihydropyrimidinediones and their metabolites
Authors: Heinkele Georg , Hofmann Ute , Opitz Joachim , Mürdter Thomas E.
Published: August 2002

Starting with uracil or thymine, [5,5,6,6‐2H4]‐dihydrouracil and [5,6,6,α,α,α,‐2H6]‐dihydrothymine were synthesised in high yields by catalytic deuteriation. Subsequent hydrolyses resulted in the corresponding β‐ureidoalkanoic acids and β‐aminoacids. Copyright © 2001 John Wiley & Sons, Ltd.
Synthesis of piperidinyl and pyrrolidinyl butyrates for potential In Vivo measurement of cerebral butyrylcholinesterase activity
Authors: Kikuchi Tatsuya , Fukushi Kiyoshi , Ikota Nobuo , Ueda Takao , Nagatsuka Shin‐ichiro , Arano Yasushi , Irie Toshiaki
Published: August 2002

Biochemical changes in postmortem brains of Alzheimer's disease patients include decreased acetylcholinesterase and choline acetyl transferase activity, indicating reduced activity of the central cholinergic system, while butyrylcholinesterase (BChE) activity increases. A method that can measure regional BChE activity in the brain in vivo may be useful for investigating the relationship between BChE and Alzheimer's disease. Seven compounds, either piperidinyl or pyrrolidinyl butyrates, were synthesized as BChE substrate radiotracers to map central BChE activity in vivo by positron emission tomography (PET). 14C‐labeled compounds were assayed to determine their hydrolysis rates by BChE and the partition coefficient. The five esters of secondary alcohols had lipophilic properties sufficient to pass readily through the blood‐brain barrier while the metabolites were sufficiently hydrophilic to be retained in the brain. The esters showed moderate hydrolysis rates by BChE and high specificity for BChE relative to acetylcholinesterase, while two esters of primary alcohols were hydrolyzed too rapidly to estimate reliably the local cerebral BChE activity. From these results, we conclude that one or more of these five esters, when labeled with 11C, would be a useful tracer for quantification of BChE activity by PET. Copyright © 2001 John Wiley & Sons, Ltd.
The synthesis of the αvβ3 integrin receptor ligand [125I]L‐775,219
Authors: Hamill Terence G. , Duggan Mark E. , Perkins Jim J.
Published: August 2002

The αvβ3 integrin receptor ligand [125I]L‐775,219, 1c, was synthesized for use in an in vitro receptor binding assay with high specific activity (>1500 Ci/mmol) and a radiochemical yield of 15–20%. Conversion of iodide 1b to the corresponding aryl trimethylstannane 2, followed by radioiodination using Na125I/iodobead gave 1c. Copyright © 2001 John Wiley & Sons, Ltd.
Synthesis of labeled galactosylhydroxylysine
Authors: Adamczyk Maciej , Reddy Rajarathnam E. , Rege Sushil D.
Published: August 2002

A concise synthesis of isotopically labeled galactosylhydroxylysine (2) was achieved via glycosylation of labeled hydroxylysine derivative (3) with (+)‐acetobromo‐α‐D‐galactose (4) and subsequent hydrolysis in good overall yield. The hydroxylysine derivative (3) was prepared from (S)‐(−)‐methyl‐2‐[bis‐(tert‐butoxycarbonyl)amino]‐5‐oxopentanoate (4) with the introduction of label (13CD2) via a Wittig reaction using 13CD3PPh3I. Copyright © 2001 John Wiley & Sons, Ltd.
Comparative anatomy of excretory organs in vestimentiferan tube worms (Pogonophora, Obturata)
Authors: Schulze Anja
Published: August 2002

In the past, the excretory systems of only few vestimentiferan species have been examined in detail. This study presents comparative data on eight species on the basis of histological serial sections. Ridgeia piscesae was studied by transmission electron microscopy. All species examined possess a central excretory organ consisting of numerous small branching and intertwined excretory tubules. These are connected to voluminous glandular excretory ducts that lead to the exterior by single or paired excretory pores located at the anterior end of the vestimentum. A comparative analysis shows differences among the species with regard to several features, such as the number of excretory pores, presence/absence of excretory grooves and papillae, position of the excretory organ relative to the brain, and the shape of the excretory ducts. Neither podocytes nor coelomoducts could be detected; therefore, there is no indication of the presence of metanephridia. The vestimentiferan excretory system shows some similarities with the design in Athecanephria (Pogonophora, Perviata) and a general resemblance to the design in sabellid polychaetes, even though in the latter metanephridia are clearly present. J. Morphol. 250:1–11, 2001. © 2001 Wiley‐Liss, Inc.
Mass allometry of the appendicular skeleton in terrestrial mammals
Authors: Christiansen Per
Published: August 2002

Most analyses on allometry of long bones in terrestrial mammals have focused on dimensional allometry, relating external bone measurements either to each other or to body mass. In this article, an analysis of long bone mass to body mass in 64 different species of mammals, spanning three orders of magnitude in body mass, is presented. As previously reported from analyses on total skeletal mass to body mass in terrestrial vertebrates, the masses of most appendicular bones scale with significant positive allometry. These include the pectoral and pelvic girdles, humerus, radius+ulna, and forelimb. Total hindlimb mass and the masses of individual hindlimb bones (femur, tibia, and metatarsus) scale isometrically. Metapodial mass correlates more poorly with body mass than the girdles or any of the long bones. Metapodial mass probably reflects locomotor behavior to a greater extent than do the long bones. Long bone mass in small mammals (<50 kg) scales with significantly greater positive allometry than bone mass in large (>50 kg) mammals, probably because of the proportionally shorter long bones of large mammals as a means of preserving resistance to bending forces at large body sizes. The positive allometric scaling of the skeleton in terrestrial animals has implications for the maximal size attainable, and it is possible that the largest sauropod dinosaurs approached this limit. J. Morphol. 251:195–209, 2002. © 2002 Wiley‐Liss, Inc.
Muscular anatomy of the millipede Phyllogonostreptus nigrolabiatus (Diplopoda: Spirostreptida) and its bearing on the millipede “thorax”
Authors: Wilson Heather M.
Published: August 2002

The muscular anatomy of the millipede Phyllogonostreptus nigrolabiatus (Newport, 1844) (Diplopoda; Spirostreptida; Harpagophoridae) is comprehensively surveyed. The musculature of the first three postcollum pleurotergites, the “thorax,” and their associated appendages was found to be more complex than that of the postthoracic rings. It is hypothesized that the musculature of the postthoracic segments is derived relative to that of the thoracic segments, which retain primitively free sternites and are not diplosegments. This hypothesis is discussed relative to previous hypotheses positing that the anteriormost three leg‐bearing rings in millipedes are diplosegments. The musculature of spirostreptid gonopods is described in detail for the first time. Comparison of the cephalic musculature is made with previously described musculature in Julida showing that, while many aspects of the musculature are conserved, there exist interordinal differences, documenting the potential utility of comparative anatomical studies for resolving millipede phylogeny. J. Morphol. 251:256–275, 2002. © 2002 Wiley‐Liss, Inc.
Selective infection of E. coli as a function of a specific molecular interaction
Authors: Nilsson Nina , Karlsson Fredrik , Rakonjac Jasna , Borrebaeck Carl A. K.
Published: August 2002

Selective infection of phage is when the bacterial infection depends on the specific molecular interaction between an antigen and a phage‐displayed protein sequence such as an antibody. Engineering of the normal infection into pathways, directed by a specific protein–protein interaction, has raised several mechanistic questions. Here, we address the type of display and the affinity between the interacting pairs. The deleted phage R408d3 was used for the first time in selective infection and was shown to exhibit a superior performance compared to the VCSM13 phage. Furthermore, the affinity between the interacting pairs also affected the selective infection process and a correlation between affinity and infection efficiency was detected, thus implying that selective infection is the method of choice for selection of rare high‐affinity interactions in molecular libraries. Copyright © 2002 John Wiley & Sons, Ltd.
Coiled coil miniprotein randomization on phage leads to charge pattern mimicry of the receptor recognition determinant of interleukin 5
Authors: Li Chuanzhao , Plugariu Carmela G. , Bajgier Joanna , White John R. , Liefer Kristin M. , Wu Sheng‐Jiun , Chaiken Irwin
Published: August 2002

Phage display was used to identify sequences that mimic structural determinants in interleukin5 (IL5) for IL5 receptor recognition. A coiled coil stem loop (CCSL) miniprotein scaffold library was constructed with its turn region randomized and panned for binding variants against human IL5 receptor α chain (IL5Rα). Competition enzyme‐linked immunosorbent assays identified CCSL‐phage selectants for which binding to IL5Rα was competed by IL5. The most frequently selected and IL5‐competed CCSL‐phage contain charged residues Arg and Glu in their turn sequences, in this regard resembling a β strand sequence in the ‘CD turn’ region, of IL5, that has been proposed to present a key determinant for IL5 receptor α chain recognition. The most dominant CCSL‐phage selectant sequence, PVEGRV, contains a negative/positive charge pattern similar to that seen in the original CD turn. To test the relatedness of CCSL‐phage selectant sequences to the IL5 receptor recognition epitope, PVEGRV was grafted into the sequence 87–92 of a monomeric IL5. The resulting IL5 variant, [87PVEGRV92]GM1, was able to bind to IL5Rα in biosensor assays, to elicit TF‐1 cell proliferation and to induce STAT5 phosphorylation in TF‐1 cells. The results help discern sequence patterns in the IL5 CD turn region which are key in driving receptor recognition and demonstrate the utility of CCSL miniprotein scaffold phage display to identify local IL5 mimetic sequence arrangements that may ultimately lead to IL5 antagonists. Copyright © 2002 John Wiley & Sons, Ltd.
Arterioportal shunts mimicking hepatic tumors with hyperintensity on T2‐weighted MR images
Authors: Matsuo Masayuki , Kanematsu Masayuki , Kondo Hiroshi , Maeda Sunaho , Goshima Satoshi , Suenaga Ichiro , Hoshi Hiroaki
Published: August 2002

We report and assess the imaging findings in a patient with multiple arterioportal shunting mimicking multiple hypervascular tumors that showed multiple areas of hyperintensity with gadolinium‐enhanced gradient‐recalled‐echo images obtained in the hepatic arterial phase and corresponding areas of slight hyperintensity with T2‐weighted images. J. Magn. Reson. Imaging 2002;15:330–333. © 2002 Wiley‐Liss, Inc.
Combined time‐resolved and high‐spatial‐resolution 3D MRA using an extended adaptive acquisition
Authors: Mazaheri Yousef , Carroll Timothy J. , Du Jiang , Block Walter F. , Fain Sean B. , Hany Thomas F. , Aagaard Beverly D.L. , Strother Charles M. , Mistretta Charles A. , Grist Thomas M.
Published: August 2002

Purpose

To combine the benefits of time‐resolved dynamic imaging and single elliptical centric acquisitions in a reasonable scan time.

Materials and Methods

A time series of images with moderate spatial resolution was acquired using the 3D Time‐Resolved Imaging of Contrast KineticS (3D TRICKS) technique with elliptical centric encoding during contrast arrival. Following venous opacification, a complete large centrically encoded k‐space volume was acquired. The high‐spatial‐frequency portions of this volume were combined with a 3D TRICKS time frame to form a high‐resolution image. An additional single image is formed by suppressing background and signal averaging all acquired data, including post‐venous low‐spatial‐frequency data. For this image, 2D temporal correlation analysis is used to suppress low‐spatial‐frequency vein contributions. Arrival time and spatial correlations are used to suppress background.

Results

The 3D TRICKS time frame may be selected to ensure a combined high‐resolution image that has optimal central k‐space sampling for any vascular region. The single image formed by signal averaging all acquired data has increased contrast‐to‐noise (CNR) and signal‐to‐noise (SNR) ratios.

Conclusion

The advantages of time‐resolved and high‐spatial‐resolution imaging were combined using an extended dual‐phase acquisition. Some SNR and CNR gain was achieved by signal averaging. This process is facilitated by background and vein suppression. J. Magn. Reson. Imaging 2002;15:291–301. © 2002 Wiley‐Liss, Inc.
A fast FLAIR dual‐echo technique for hippocampal T2 relaxometry: First experiences in patients with temporal lobe epilepsy
Authors: Woermann Friedrich G. , Steiner Herbert , Barker Gareth J. , Bartlett Philippa A. , Elger Christian E. , Duncan John S. , Symms Mark R.
Published: August 2002

To evaluate the use of cerebrospinal fluid (CSF) signal nulling in MR T2 measurements of the hippocampus in normal control subjects and patients with temporal lobe epilepsy (TLE), dual‐echo acquisitions covering the whole brain were used. T2 relaxation times were estimated in 12 standard Eurospin II MR test objects and in the hippocampi of 10 control subjects, using T2 maps constructed from conventional spin‐echo (CSE), fast spin‐echo (FSE), and fast FLAIR (FF) dual‐echo sequences on a 1.5‐T MR scanner. Hippocampal T2 values (HCT2) were measured on contiguous coronal 5‐mm slices throughout the antero‐posterior extent of each hippocampus in the 10 controls and 12 TLE patients, using both CSE and FF. Scan‐rescan reproducibility in Eurospin II standard MR test objects was high for all sequences. There was a good correlation between T2 values from CSE, FF, and FSE sequences in test objects and in control hippocampi. In controls, the coefficient of variation of mean HCT2 values differed between slice positions, but was lowest for FF, followed by CSE data. The intrarater coefficient of reliability between repeated measurements in control subjects was lowest for FF HCT2, at 2.3%. The interrater coefficient of reliability for CSE HCT2 measurements in controls (4.8%) was slightly lower than the interrater coefficient for FF HCT2 (5.4%). HCT2 measurement with both CSE and FF identified abnormal values in the same 10 hippocampi of 12 patients. Hippocampal dual‐echo T2 relaxometry using CSF nulling is reliable in control subjects, and identifies the abnormal hippocampi in patients with TLE. The increases in hippocampal T2 signal demonstrated using FF HCT2 measurements are unlikely to be partial volume effects from CSF. J. Magn. Reson. Imaging 2001;13:547–552. © 2001 Wiley‐Liss, Inc.
Language dominance assessment by means of fMRI: Contributions from task design, performance, and stimulus modality
Authors: Hund‐Georgiadis Margret , Lex Ulrike , von Cramon D. Yves
Published: August 2002

We investigated the influence of different task demands, task designs, and presentation modalities on the functional MRI activation patterns during a language lateralization task in a group of 14 right‐handed control subjects. A word classification task was presented as target task appropriate to evoke language‐related activation in the inferior frontal gyrus (IFG). The choice of the contrasting baseline task was demonstrated to have a major impact on the functional outcome: While a fixation baseline elicited activations in the inferior frontal gyrus of both hemispheres, a nonsemantic perceptual control task helped to isolate the relevant target task of word classification. The modality of stimulus presentation did not influence the functional data: Auditory and visual presentation modes broadly evoked activations in similar brain regions during word classification. Minor differences in task performance and the side of the responding hand did not interfere with the functional activation patterns of the target task. On the basis of our results, a protocol of functional lateralization in the inferior frontal gyrus is suggested. J. Magn. Reson. Imaging 2001;13:668–675. © 2001 Wiley‐Liss, Inc.
Collision‐induced fragmentation of deprotonated methoxylated flavonoids, obtained by electrospray ionization mass spectrometry
Authors: Justesen Ulla
Published: August 2002

Electrospray operated in the negative mode was used to analyse methoxylated flavonoids. They were found to produce radical anions by collision‐induced fragmentation of the aglycones. Loss of a methyl group from the deprotonated molecule corresponding to [M − H − 15]−. ions, as well as [M − H − 15–28]−. and [M − H − 15–29]− fragment ions, were found to constitute the characteristic fragmentation for the monomethoxylated species, whereas [M − H − 15]−., [M − H − 30]− and [M − H − 30–28]− were predominant for the polymethoxylated species. Obtained under similar conditions, the product‐ion spectra of isomeric compounds were characteristically different. It is therefore possible to distinguish between methoxylated flavonoids with identical molecular mass, e.g. when screening plant extracts for flavonoid composition. However, comparison with standard compounds is necessary for the identification of unknown flavonoid aglycones. Copyright © 2001 John Wiley & Sons, Ltd.
Interaction between synthetic amyloid‐β‐peptide (1–40) and its aggregation inhibitors studied by electrospray ionization mass spectrometry
Authors: Skribanek Zsolt , Baláspiri Lajos , Mák Marianna
Published: August 2002

It is generally postulated that amyloid‐β‐peptides play a central role in the progressive neurodegeneration observed in Alzheimer's disease. Important pathological properties of these peptides, such as neurotoxicity and resistance to proteolytic degradation, depend on the ability of amyloid‐β‐peptides to form β‐sheet structures and/or amyloid fibrils. Amyloid‐β‐peptides are known to aggregate spontaneously in vitro with the formation of amyloid fibrils. The intervention on the amyloid‐β‐peptides aggregation process can be envisaged as an approach to stopping or slowing the progression of Alzheimer's disease. In the last few years a number of small molecules have been reported to interfere with the in vitro aggregation of amyloid‐β‐peptides. Melatonin, a hormone recently found to protect neurons against amyloid‐β‐peptide toxicity, interacts with amyloid‐β‐peptide (1–40) and amyloid‐β‐peptide (1–42) and inhibits the progressive formation of β‐sheet and/or amyloid fibrils. These interactions between melatonin and the amyloid peptides have been demonstrated by circular dichroism (CD) and electron microscopy for amyloid‐β‐peptide (1–40) and amyloid‐β‐peptide (1–42) and by nuclear magnetic resonance (NMR) spectroscopy for amyloid‐β‐peptide (1–40). Our electrospray ionization mass spectrometric (ESI‐MS) studies also proved that there is a hydrophobic interaction between amyloid‐β‐peptide (1–40) and melatonin and the proteolytic investigations suggested that the interaction took place on the 29–40 amyloid‐β‐peptide segment. The wide‐ranging application of these results would provide further information and help in biological research. Copyright © 2001 John Wiley & Sons, Ltd.
Structural characterization of lipopeptide biomarkers isolated from Bacillus globigii
Authors: Williams Bruce H. , Hathout Yetrib , Fenselau Catherine
Published: August 2002

Spectra obtained using matrix‐assisted laser desorption/ionization (MALDI) mass spectrometry of Bacillus globigii (Bacillus subtilis niger) spores, vegetative cells and the culture supernatant show a cluster of biomarkers centered at a molecular mass of 1478 Da. Three biomarkers were isolated from the cell‐free culture supernatant by solid‐phase extraction and reversed‐phase high‐performance liquid chromatography, and characterized using various kinds of mass spectrometry. A Fourier transform mass spectrometer with a MALDI source was used to determine the monoisotopic protonated masses at 1463.8, 1477.8, and 1505.8 Da in order of elution. The mass differences of 14 and 28 Da suggest that they are homologous molecules. Alkaline hydrolysis of each species showed that it contained a lactone linkage. Strong acid hydrolysis released a fatty acid from an amide bond, consistent with a lipopeptide. A quadrupole time‐of‐flight instrument with a nanospray source was used to sequence the hydrolyzed forms of the three biomarkers. The cyclic lipopeptides were found to have amino acid sequences identical with those in fengycins and plipastatins, antimicrobial compounds with phospholipase inhibitor activity, previously identified in related species of Bacillus subtilis and Bacillus cereus. Copyright © 2002 John Wiley & Sons, Ltd.
A regulatory region rearranged BK virus is associated with tubulointerstitial nephritis in a rejected renal allograft
Authors: Chen Chen‐Hsu , Wen Mei‐Chin , Wang Meilin , Lian Jong‐Da , Wu Ming‐Ju , Cheng Chi‐Hung , Shu Kuo‐Hsiung , Chang Deching
Published: August 2002

A renal allograft transplant patient with high serum creatinine presented clinical symptoms of rejection. Sections of renal biopsy tissue showed mononuclear leukocyte infiltration in the tubulointerstitium and nuclear enlargement with inclusions in the tubular epithelium. The morphological characteristics resembled polyomavirus‐induced interstitial nephritis. Electron microscopy of the nuclear inclusions showed paracrystalline arrays of naked viral particles with a diameter of 45 nm. Molecular studies revealed that a new variant of BK virus (BKV) with rearrangement at the regulatory region was involved in the nephritis. The BKV regulatory region contained a tandem repeat from the P‐block to the Q‐block causing duplication of several important transcriptional elements or transcriptional factor binding motifs. This is the first report to show a naturally occurring BKV variant with regulatory region rearrangement associated with tubulointerstitial nephritis. J. Med. Virol. 64:82–88, 2001. © 2001 Wiley‐Liss, Inc.
Construction of Oka varicella vaccine expressing human immunodeficiency virus env antigen
Authors: Shiraki Kimiyasu , Sato Hitoshi , Yoshida Yoshihiro , Yamamura Jun‐ichi , Tsurita Minako , Kurokawa Masahiko , Kageyama Seiji
Published: August 2002

Oka varicella vaccine has been used to confer active immunity to varicella‐zoster virus (VZV) in healthy and immunocompromised hosts. Based on its attenuated nature, Oka varicella vaccine expressing human immunodeficiency virus (HIV) env antigen was constructed by inserting the HIVenv gene into the viral genome and its immunogenicity was assessed in guinea pigs. The HIVenv gene encoding 296–463 amino acids was inserted between the sequences of the hepatitis B surface antigen and the thymidine kinase gene of the cloned plasmid and the recombinant virus was isolated by cotransfection of the chimeric plasmid with viral DNA. Insertion of the HIVenv gene into the viral genome was confirmed by PCR and sequencing of the viral genome of the recombinant virus. The recombinant virus expressed 30k HIVenv fusion protein in its infected cells. In guinea pigs, immunization with the recombinant virus induced an antibody response to both the HIV antigen and the V3 peptide of gp120 as well as VZV gE:gI. Cell‐mediated immunity to the HIV antigen and gE:gI was assessed by the cutaneous reaction representing delayed type hypersensitivity. Immunized guinea pigs responded well to both the HIV antigen and gE:gI. Thus the recombinant Oka varicella vaccine expressing the HIVenv antigen induced both a humoral and cell‐mediated immunity to the HIV antigen similar to VZV as Oka varicella vaccine induces humoral and cell‐mediated immunity to VZV in the vaccinees. This recombinant Oka varicella vaccine expressing the HIVenv antigen may be evaluated for its immunogenicity as one of the AIDS vaccine candidates. J. Med. Virol. 64:89–95, 2001. © 2001 Wiley‐Liss, Inc.
Complete replication of human cytomegalovirus in explants of first trimester human placenta
Authors: Gabrielli Liliana , Losi Luisa , Varani Stefania , Lazzarotto Tiziana , Eusebi Vincenzo , Landini Maria Paola
Published: August 2002

Tissue integrity and viability of first trimester placenta explants were obtained in culture for 3 weeks. Explants were infected with human cytomegalovirus (HCMV), several cycles of HCMV replication were obtained and the progression of the infection was observed within a tissue that maintains its normal cellular organization. In agreement with recent clinical data, 3 weeks were necessary for the virus to colonize the placenta fully. Complete HCMV replication was observed in trophoblasts, followed by subsequent transmission of the infection to the stromal fibroblasts and fetal endothelial capillary cells. Viral DNA replication was monitored and the production of infectious viral progeny documented. J. Med. Virol. 64:499–504, 2001. © 2001 Wiley‐Liss, Inc.
Type‐specific identification of human adenovirus 3, 7, and 21 by a multiplex PCR assay†
Authors: Xu WanHong , Erdman Dean D.
Published: August 2002

Human adenovirus (Ad) serotypes 3, 7, and 21 of DNA cluster B:1 are often associated with severe respiratory illness, particularly in infants and young children and, in addition to Ad4, are among the most important causes of acute respiratory disease syndrome in new military recruits. To address the inherent problems associated with classic typing methods, we developed a multiplex PCR assay for the rapid, specific identification of Ad3, Ad7, and Ad21 field isolates. To design type‐specific primers for our assay, we sequenced the Ad21 hexon gene and compared this sequence with previously published sequences of Ad3, Ad7, and Ad16. The overall nucleotide (nt) and amino acid (aa) identities between Ad21 and Ad3, Ad7, and Ad16 were similar (ranges 78.3–80.8% nt; 84.1–86.2% aa), with significantly greater variability in the regions of the hexon that encode surface loops 1 and 2. Type‐specific primers designed to the hypervariable regions correctly identified Ad3, Ad7, and Ad21 prototype strains and 53 previously typed Ad field isolates. No cross‐reactions with other Ad serotypes were identified. Our multiplex PCR assay for type‐specific identification of Ad3, Ad7, and Ad21 isolates will provide a rapid and convenient tool for the epidemiologic investigation of Ad‐associated respiratory illness. J. Med. Virol. 64:537–542, 2001. © 2001 Wiley‐Liss, Inc.
Transmission of HCV to a chimpanzee using virus particles produced in an RNA‐transfected HepG2 cell culture
Authors: Dash Srikanta , Kalkeri Gururaj , McClure Hazel M. , Garry Robert F. , Clejan Sanda , Thung Swan N. , Murthy Krishna K.
Published: August 2002

It was demonstrated previously that HepG2 cells produce negative strand RNA and virus‐like particles after transfection with RNA transcribed from a full‐length hepatitis C virus (HCV) cDNA clone [Dash et al. (1997) American Journal of Pathology, 151:363‐373]. To determine in vivo infectivity of these in vitro synthesized viral particles, a chimpanzee was inoculated intravenously with HCV derived from HepG2 cells. The infected chimpanzee was examined serially for elevation of liver enzymes, for the presence of HCV RNA in the serum by reverse transcription nested polymerase chain reaction (RT‐PCR), anti‐HCV antibodies in the serum, and inflammation in the liver. The chimpanzee developed elevated levels of liver enzymes after the second week, but the levels fluctuated over a 10‐week period. HCV RNA was detected in the serum of the chimpanzee at the second, seventh and ninth weeks after inoculation, and remained positive up to 25 weeks. Liver biopsies at Weeks 18 and 19 revealed of mild inflammation. Nucleotide sequence analysis of HCV recovered from the infected chimpanzee at the second and ninth weeks showed 100% sequence homology with the clone used for transfection studies. Serum anti‐HCV antibodies were not detected by EIA during the 25 weeks follow‐up period. These results suggest that intravenous administration of the virus‐like particles derived from RNA‐transfected HepG2 cells are infectious, and therefore, the pMO9.6‐T7 clone is an infectious clone. These results provide new information that in vitro synthesized HCV particles produced from full‐length HCV clone can cause infection in a chimpanzee. This study will facilitate the use of innovative approaches to the study of assembly of HCV particles and mechanisms of virus infectivity in cell culture. J. Med. Virol. 65:276–281, 2001. © 2001 Wiley‐Liss, Inc.
Direct correlation between human herpesvirus‐8 seroprevalence and classic Kaposi's sarcoma incidence in Northern Sardinia
Authors: Santarelli Roberta , De Marco Roberto , Masala Maria Vittoria , Angeloni Antonio , Uccini Stefania , Pacchiarotti Roberta , Montesu Maria Antonietta , Satta Rosanna , Cerimele Decio , Faggioni Alberto , Cottoni Francesca
Published: August 2002

The human herpesvirus‐8 (HHV‐8) has been associated with the development of Kaposi's sarcoma. A high incidence of classic Kaposi's sarcoma has been described in Sardinia, an island West of Italy's mainland. Different seroepidemiological analyses have reported that prevalence of HHV‐8 infection varies worldwide: a high HHV‐8 seroprevalence has been shown in Italy. The present survey was carried out to evaluate the correlation between HHV‐8 infection and classic Kaposi's sarcoma incidence in northern Sardinia. Blood samples were collected from 226 healthy donors born and resident in five different areas of North Sardinia. Seroprevalence to HHV‐8 was determined searching antibodies to viral lytic proteins by immunofluorescence in sera diluted at 1:10. Classic Kaposi's sarcoma incidence data spanning a period of 23 years were examined in the areas studied. The present screening revealed that seroprevalence was 35%, within a range of 15.3–46.3% in the five areas, although it should be considered that the seroprevalence to HHV‐8 can be established more accurately by the combined use of different assays. Age emerged as an important risk factor. Indeed, subjects aged > 50 years showed a higher seroprevalence to HHV‐8 as compared with younger individuals. A strong direct correlation between HHV‐8 prevalence and classic Kaposi's sarcoma incidence has been also observed. The wide diffusion of HHV‐8 in Sardinia appears to represent an important factor in the high incidence of classic Kaposi's sarcoma reported in the island. However, additional co‐factors, such as age, sex, genetic traits, or viral strain pathogenicity, are likely to play a role in the development of the disease. J. Med. Virol. 65:368–372, 2001. © 2001 Wiley‐Liss, Inc.