bluuebunny/crossref_metadata_2025 huggingface dataset:
Use of an adsorbed chiral selector in capillary LC‐MS
Authors: Törnkvist Anna , Sjöberg Per J.R. , Markides Karin E. , Heldin Eva
Published: October 2002

Lasalocid was utilized as a chiral selector adsorbed on porous graphitic carbon. Important parameters were identified for the use of the chiral selector in capillary liquid chromatography combined with MS detection. The influence on both retention and enantioselectivity as well as mass spectrometric performance was studied at lasalocid concentrations of up to 12 mg/l (20 μM). Moreover, the stability of retention factors and enantioselectivities was also evaluated at low selector concentration of 1 mg/l (2 μM). The results show that in order to optimize the MS performance the selector concentration should be kept at low μM. The chromatographic performance at reduced selector concentration (1 mg/l = 2 μM) was studied over a 10‐days period, showing satisfactory enantioselectivity and stable performance concerning enantioselectivity and retention. Chirality 14:653–658, 2002. © 2002 Wiley‐Liss, Inc.
Protein phosphorylation regulates actomyosin‐driven vesicle movement in cell extracts isolated from the green algae, Chara corallina
Authors: Morimatsu Miki , Hasegawa Satoshi , Higashi‐Fujime Sugie
Published: October 2002

In Characean cells endoplasmic streaming stops upon membrane depolarization accompanied by Ca2+ entry. We investigated the mechanism of this cessation of endoplasmic streaming by reconstituting the vesicle movement in vitro. In a living cell of Chara corallina, there are a number of vesicles moving along actin cables. Vesicles in the endoplasm squeezed out of the cell into a medium containing Mg‐ATP showed directional movements under a dark field microscope. When the extracted endoplasm was treated with 20 nM okadaic acid, vesicles showed only movements like the Brownian motion. When it was treated with 50 nM staurosporine, directional movements of vesicles were activated. These movements were analyzed by image processing of videomicroscopic records. Vesicle movements along F‐actin filaments were also observed by merging both images of the same field by dark field microscopy and fluorescence microscopy, indicating that myosin on the vesicle surface was responsible for vesicle movements. We also examined the effects of okadaic acid and staurosporine on in vitro sliding of F‐actin on Chara myosin. When Chara myosin was treated with 20 nM okadaic acid in the cell extract, the number of sliding F‐actin filaments was greatly reduced. In contrast, it increased when Chara myosin was treated with 50 nM staurosporine. In addition, Chara myosin treated with protein kinase C greatly diminished its motility. These results suggest that inactivation of Chara myosin via its phosphorylation is responsible for cessation of endoplasmic streaming. Cell Motil. Cytoskeleton 53:66–76, 2002. © 2002 Wiley‐Liss, Inc.
Human osteosarcoma expresses specific ephrin profiles
Authors: Varelias Antiopi , Koblar Simon A. , Cowled Prudence A. , Carter Christopher D. , Clayer Mark
Published: October 2002

BACKGROUND

The molecular mechanisms underlying malignancy of osteosarcoma are unknown. It has been reported that eph receptor protein tyrosine kinases and their ligands, ephrins, are associated with increased tumorigenicity in patients with breast carcinoma and melanoma. The expression and role of eph/ephrins in human osteosarcoma has not yet been characterized.

METHODS

Ephrin‐A1, ephrin‐A3, ephrin‐A4, ephrin‐A5, ephrin‐B1, ephrin‐B2, and ephrin‐B3 mRNA expression was examined by reverse transcription polymerase chain reaction analysis in nine specimens of human osteosarcoma tissue and five human osteosarcoma cell lines. Ephrin‐B1 protein expression was detected immunohistochemically in human osteosarcoma tissue. Clinicopathologic correlation was made between the osteosarcoma specimens and their ephrin expression profiles.

RESULTS

Normal bone specimens, osteosarcoma tissue specimens, and osteosarcoma cell lines expressed a distinct mRNA profile of ephrin‐A1, ephrin‐A4, and ephrin‐B2. A second mRNA profile that included ephrin‐A3, ephrin‐A5, and ephrin‐B1 was expressed by a subset of tumors. The expression of ephrin‐B1 was correlated with a poorer clinical prognosis. Ephrin‐B1 protein was expressed by osteosarcoma cells and blood vessels.

CONCLUSIONS

The results of this study suggest that ephrin‐B1 expressed by osteosarcoma may be a poor prognostic marker through increased tumorigenicity. Cancer 2002;95:862–9. © 2002 American Cancer Society.

DOI 10.1002/cncr.10749
Complementary and layered expression of Ephs and ephrins in developing mouse inner ear
Authors: Pickles James O. , Claxton Christina , Van Heumen Walter R.A.
Published: October 2002

The distributions of the Eph‐class receptors EphA4 and EphB1, and their ligands ephrin‐A2, ephrin‐B1, and ephrin‐B2, were analysed by immunostaining in the mouse inner ear. Complementary patterns of EphA4 and its potential ligand ephrin‐A2 were found, with ephrin‐A2 in many of the structures lining the cochlear duct and within the cochlear nerve cells, and EphA4 in the deeper structures underlying the cochlear duct and in the cells lining the nerve pathway. EphB1 and its potential ligands ephrin‐B1 and ephrin‐B2 showed a segregated layered expression in the lateral wall of the cochlear duct (the external sulcus), which together with EphA4 expressed in the area, form a four‐layered structure with an alternating pattern of receptors and ligands in the different layers. This arrangement gives the potential for different bidirectional Eph‐mediated interactions between each of the layers. The results suggest that the Eph system in the cochlea may have a role in maintaining cell segregation during phases of cochlear development. J. Comp. Neurol. 449:207–216, 2002. © 2002 Wiley‐Liss, Inc.
Organization of trigeminocollicular connections and their relations to the sensory innervation of the eyelids in the rat
Authors: Ndiaye Awa , Pinganaud Gabrielle , Buisseret‐Delmas Catherine , Buisseret Pierre , Vanderwerf Frans
Published: October 2002

Relationships between the trigeminal component of blinking and the superior colliculus (SC) were studied in rats. To localize primary afferent eyelid projections in the sensory trigeminal complex, neuronal tracing experiments were performed as well as analysis of c‐Fos protein expression after supraorbital (SO) nerve stimulation. Labelled nerve fibers were found to enter ventrally within the ipsilateral sensory trigeminal complex. Labelled boutons were observed at the junction of the principal nucleus (5P) and the pars oralis (5o) and in the pars caudalis (5c). The c‐Fos immunoreactivity was observed in neurons located in the ipsilateral ventral parts of 5P, 5o, and the pars interpolaris (5i) and bilaterally in 5c. Injections in 5P, 5o, 5i, and 5c resulted in anterogradely labelled fibers, with a contralateral preponderance, within the intermediate and deeper SC layers. Injections in 5P or 5o showed anterogradely labelled nerve fibers, profusely terminating in small patches in the medial and central portions of SC layer 4. Subsequently, dense labelling was found in the lateral portion of SC layers 4–7, without patch‐like organization. Injections in SC showed retrogradely labelled neurons predominantly within the contralateral part of the sensory trigeminal complex (28% in 5P, 20% in 5o, 50% in 5i, and 2% in 5c). Colocalization of the retrograde tracer after SC injections and c‐Fos immunoreactivity in neurons demonstrated that some 5P, 5o, and 5i neurons receive SO nerve inputs and project to SC. This implies that intermediate and deeper SC layers receive sensory information from the eyelids and may be directly involved in the regulation of eye–eyelid coordination. J. Comp. Neurol. 448:373–387, 2002. © 2002 Wiley‐Liss, Inc.
Alterations to neuronal polarity following permanent axotomy: A quantitative analysis of changes to MAP2a/b and GAP‐43 distributions in axotomized motoneurons in the adult cat
Authors: MacDermid Victoria , Neuber‐Hess Monica , Short Carly , Rose P. Ken
Published: October 2002

Following axotomy, morphologically unusual, distal processes (UDPs) emerge from motoneuron dendrites. These processes contain an axonal protein, growth‐associated protein 43 (GAP‐43) but lack immunostaining for the dendritic protein microtubule‐associated protein 2a/b (MAP2a/b). Thus, it appears that neuronal polarity alters following axotomy. Our goal was to describe this change in neuronal polarity on a more detailed and quantitative level. We asked two questions: Following axotomy, where in the entire neuron does the immunoreactivity for MAP2a/b and GAP‐43 change and do these changes reflect a transformation of dendrite to axon or growth from terminal dendrites? Using intracellular labeling and immunocytochemistry, changes in MAP2a/b and GAP‐43 immunoreactivity were also found in processes with a morphology typical of terminal branches of intact motoneurons (called simple distal processes [SDPs]), as well as UDPs. Trajectories (the path from the soma to a single terminus) with UDPs and SDPs were longer than trajectories without these processes, and trajectories with UDPs were the longest. Trajectories without UDPs or SDPs were similar in length to trajectories from intact motoneurons. The distance from the soma to the point where MAP2a/b immunoreactivity became absent in trajectories with UDPs or SDPs was similar to the length of trajectories from intact motoneurons. Thus, following axotomy, two morphologically distinct types of axon‐like processes emerge from dendrites. The formation of these processes does not involve a transformation of the original dendrite, but rather growth at the ends of dendrites. J. Comp. Neurol. 450:318–333, 2002. © 2002 Wiley‐Liss, Inc.
A ‘pure’ boundary node method for potential theory
Authors: Gowrishankar Ramesh , Mukherjee Subrata
Published: October 2002

The standard boundary node method (BNM) uses a (meshless) diffuse interpolation (in terms of neighbouring scattered boundary points) for the primary variables. The method is not ‘truly meshless’, however, since cells on the boundary of a body are used for integration. This paper presents a ‘pure’ version of the BNM in which integration cells are dispensed with. Instead (overlapping), regions of influence (ROIs) of boundary nodes are used for integration. Initial results for 2‐D potential theory, presented here, are encouraging. Copyright © 2002 John Wiley & Sons, Ltd.
Homogenized high precision direct integration scheme and its applications in engineering
Authors: Wang Yuexian , Tian Xiaodong , Zhou Gang
Published: October 2002

Dynamics response of systems to impact or loading may be effectively treated by direct integration. However, it is often difficult to select the time‐step of integration properly, especially in the case where the system is badly stiff. Zhong presented an explicit direct integration scheme, HPD, for the homogeneous systems. This paper extends HPD scheme to analyse systems with loading or impact, through Fourier expansion and homogenizing the initial system. Compared with other methods, the new scheme named homogenized high‐precision direct integration (HHPD) has a higher precision and wider application and is less time‐consuming, and several examples in this paper show HHPD's effectiveness in engineering. Copyright © 2002 John Wiley & Sons, Ltd.
Identification of “papillary‐like” clusters on endometrial cytologic preparations
Authors: Ono Midori , Shiina Yoshio , Sakuma Kanae
Published: October 2002

The presence of papillary cell clusters is taken as a serious indication in the diagnosis of well‐differentiated endometrial adenocarcinoma in Japan. However, papillary‐like clusters have been observed in both normal and benign samples. Therefore, overdiagnosis may occur in the observation of cytopreparations. The present study attempts to prepare a histological sample from an Auto Cyto Fix (ACF) sample prepared by the automatic fixation apparatus (ACF1000) using a membrane filter method after cytological observation and to examine its usefulness. In an ACF sample, a papillary‐like cluster was observed and the coverslip was then removed, the circumference of the membrane filter was cut off, and the target cell cluster was smeared, embedded, and sliced. In the cases in which a papillary‐like cluster was observed, even if differential diagnosis of the derivation was difficult due to a resemblance between the respective morphological findings, it was easily made by histological observation of an ACF sample. Diagn. Cytopathol. 2002;27:15–21. © 2002 Wiley‐Liss, Inc.
Pax3 and Dach2 positive regulation in the developing somite
Authors: Kardon G. , Heanue T.A. , Tabin C.J.
Published: October 2002

In vertebrates, skeletal muscles of the body arise from cells of somitic origin. Recently, somite culture experiments have identified a set of genes, including Pax3, Six1, Eya2, and Dach2, that appear to play an important role in early myogenesis during somite development (Heanue et al. [1999] Genes Dev. 13:3231–3243). In somite culture Pax3, Six1, Eya2, and Dach2 not only function to activate myogenesis, but they form a complex network regulating each other's transcription. We sought to examine whether this putative Pax3/Six1/Eya2/Dach2 network of regulation actually functions in vivo. In particular, we tested whether Pax3 and Dach2 participate in a positive regulatory feedback loop in vivo as they do in culture. To test in vivo Pax3/Dach2 interregulation, we took advantage of the known dependence of both factors on ectodermal signals. Somites isolated from the overlying ectoderm lose expression of Pax3 and Dach2. Therefore, we attempted to rescue Pax3 or Dach2 expression in somites isolated from the ectoderm by retroviral misexpression of the complementary factor. Indeed misexpression of Pax3 or Dach2 resulted in rescue of Dach2 or Pax3, respectively. These rescue experiments demonstrate that Pax3 and Dach2 positively regulate each other's expression in vivo and support the validity of the Pax3/Six1/Eya2/Dach 2 network in regulating myogenesis. © 2002 Wiley‐Liss, Inc.
Transition between proliferation and differentiation for lens epithelial cells is regulated by Src family kinases
Authors: Walker Janice L. , Zhang Liping , Menko A. Sue
Published: October 2002

As in many cell types, lens cells must withdraw from the cell cycle before they initiate their differentiation. The involvement of Src family kinases (SFKs) in this key initiating event in cell differentiation was examined in lens epithelial cell cultures. SFK activity was suppressed with the specific inhibitor PP1. This induced expression of the cyclin‐dependent kinase (CDK) inhibitors p27 and p57 and suppressed lens epithelial cell proliferation. Therefore, inhibition of SFK activity created conditions permissive for undifferentiated lens epithelial cells to withdraw from the cell cycle. Growth of the lens epithelial cell cultures in the presence of PP1 induced expression of filensin and CP49, lens differentiation‐specific intermediate filament proteins, providing evidence that suppression of SFK activity also promoted the initiation of lens cell differentiation. The mechanism by which PP1 signaled cell cycle withdrawal and commitment to differentiation was shown to involve induction of N‐cadherin cell–cell junction assembly and reorganization of the actin cytoskeleton from stress fibers to cortical filaments. This result was supported by the compaction of the epithelial monolayer in response to PP1, a morphogenetic change that we have previously shown to be dependent on N‐cadherin function and a hallmark of the commencement of the lens differentiation program in culture. The results presented in this study suggest that the decision of lens epithelial cells to withdraw from the cell cycle and initiate differentiation requires inhibition of SFKs and the formation of N‐cadherin cell–cell junctions. © 2002 Wiley‐Liss, Inc.
TnIfast IRE enhancer: Multistep developmental regulation during skeletal muscle fiber type differentiation
Authors: Hallauer Patricia L. , Hastings Kenneth E.M.
Published: October 2002

To identify developmental steps leading to adult skeletal muscle fiber‐type–specific gene expression, we carried out transgenic mouse studies of the IRE enhancer of the quail TnIfast gene. Histochemical analysis of IRE/herpesvirus tk promoter/β‐galactosidase reporter transgene expression in adult muscle directly demonstrated IRE‐driven fast vs. slow fiber‐type specificity, and IIB>IIX>IIA differential expression among the fast fiber types: patterns similar to those of native‐promoter TnIfast constructs. These tissue‐ and cell‐type specificities are autonomous to the IRE and do not depend on interactions with a muscle gene promoter. Developmental studies showed that the adult pattern of IRE‐driven transgene expression emerges in three steps: (1) activation during the formation of primary embryonic (presumptive slow) muscle fibers; (2) activation, to markedly higher levels, during formation of secondary (presumptive fast) fibers, and (3) differential augmentation of expression during early postnatal maturation of the IIB, IIX, IIA fast fiber types. These results provide insight into the roles of gene activation and gene repression mechanisms in fiber‐type specificity and can account for apparently disparate results obtained in previous studies of TnI isoform expression in development. Each of the three IRE‐driven developmental steps is spatiotemporally associated with a different major regulatory event at the fast myosin heavy chain gene cluster, suggesting that diverse muscle gene families respond to common, or tightly integrated, regulatory signals during multiple steps of muscle fiber differentiation. © 2002 Wiley‐Liss, Inc.
Performance evaluation of data transfer on multiple routes through the Internet
Authors: Hayashi Takanori , Yamasaki Shin'ichiro , Morita Naoto , Aida Hitoshi , Takeichi Masato , Doi Norihisa
Published: October 2002

In this paper, we examined a data transfer scheme that distributes packets to multiple routes over the Internet and evaluated this scheme by simulating the packet distribution method in the routes and the effect of resequencing the packet order. The simulation examined file transfers over two routes having the same transmission rate. The fixed transfer delay time, delay variations, and packet losses indicated the network quality. When distributing packets to the route having a short send buffer time on the data transfer side and resequencing packets on the data receiving side, the most stable throughput was obtained by a scheme that released the queue when given a packet loss decision when the sequencing of the data was not updated even if packets were received from two routes. In addition, if the scheme alternately routes the packets between two routes when the difference in the delay times of the two routes falls within four packet times, the same performance as the previous scheme is obtained even without resequencing the packets. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 85(12): 89–99, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.1144
Analysis of received level characteristics with transmitter power control in DS‐CDMA system
Authors: Fujii Teruya , Miki Yoshinori
Published: October 2002

In a broadband DS‐CDMA system, control of transmitter power is indispensable in order to solve the distance problem of mobile stations, in which the transmitter power of mobile stations is adaptively controlled so that the received power at the base station remains constant. In a DS‐CDMA system, the paths can be separated and RAKE reception can be applied, which helps to reduce the transmitted power as well as the error in transmitter power control. This paper considers the case in which transmitter power control by feedback is applied to a DS‐CDMA system, and analyzes the effects of control parameters such as the control time interval, the maximum amount of control, and the control step width, on the error of the transmitter power control, considering path and antenna diversity. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 85(12): 100–111, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.1145
High‐order vector elements for finite element electromagnetic analysis and subspace method in large‐scale eigenvalue problems
Authors: Hano Mitsuo
Published: October 2002

In three‐dimensional electromagnetic field analysis by the finite element method, the function space of the higher‐order vector elements is separated into the gradient field and the rotational field and a new configuration method for the shape function is proposed. For a large‐dimensional eigenvalue problem with unique zero eigenvalue in the electromagnetic eigenvalue problem, the subspace method containing an algorithm eliminating the null space is proposed. When these methods are applied to the analysis of a cubic cavity resonator, fast analysis of a large‐dimensional eigenvalue problem becomes possible. In addition, it is found that more accurate solutions can be obtained with the higher‐order vector elements in the same computation time. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 85(7): 57–65, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.10017
Planar three‐way power divider using short terminated stubs in the center of isolation bridges
Authors: Ikeda Yukio , Takeda Fumio , Tuda Kazuya , Ishida Osami
Published: October 2002

A new planar three‐way Wilkinson power divider is described in which the output terminals are connected by isolation bridges. Short circuit stubs to cancel the capacitance component of the series resonant circuit are attached at the midpoints of the isolation bridges. A design formula is derived. In addition, it is theoretically and experimentally demonstrated that the bandwidth with a return loss of more than 20 dB is wider than the conventional Wilkinson power divider. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 85(8): 1–8, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.10042
Bifurcations and intermittent chaos observed in a ring of four‐coupled PLLs
Authors: Hasegawa Akio , Komura Motomasa , Endo Tetsuro , Igarashi Ryo
Published: October 2002

In this paper, we study various types of bifurcations of attractors observed in computer simulation and electronic circuit experiment of the ring of four‐coupled PLLs when coupling coefficient σ is increased and the route to chaos is made clear. In particular, for intermittent chaos that is observed when σ becomes large, we study the laminar distribution, time variation of local expansion rate, and Lyapunov exponent. We have shown the existence of several kinds of intermittent chaos with different properties. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 85(12): 56–64, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.1128
Estimation of mutation rate at human glycophorin A locus in hematopoietic stem cell progenitors
Authors: Vickers M. A. , Hoy T. , Lake H. , Kyoizumi S. , Boyse J. , Hewitt M.
Published: October 2002

Surveys of human mutant cells exhibit a few individuals with relatively high “outlying” values, which might be explained by rare mutations occurring during development. To estimate how commonly this occurs, mutant red cell frequencies at the glycophorin A locus in 135 neonates and 109 children and adolescents from three research centers are compared with simulations in which mutations arise from successive cycles of binary fission. The simulations predict the data most accurately when the mutation rate in stem cell precursors is about 2–4 × 10−7 per division cycle, which is similar to previous estimates from adult stem cell divisions. If these mutation rates are accurate, and the number of stem cell divisions during adult life is as low as previously estimated, it is predicted that up to one‐sixth of mutant stem cells over a lifetime arose in early life. However, these mutant stem cells would be difficult to detect in surveys because their distribution within the general population is so skewed. Environ. Mol. Mutagen. 39:333–341, 2002. © 2002 Wiley‐Liss, Inc.
Numerical simulation for rotating internal weakly viscoelastic flows in rectangular ducts
Authors: de Bortoli A. L. , Thompson M. , Zavaleta Calderon A. U.
Published: October 2002

The present work develops a numerical method for the solution of rotating internal weakly viscoelastic flows in rectangular ducts for dimensionless parameters such as the Reynolds, Rossby and Weissenberg numbers, taken respectively in the intervals between 171 and 12000, 0.047 and 1/12 and up to 1/10000. It is shown that the usual counter‐rotating double‐vortex configuration of secondary flow breaks down with the increase of the Reynolds number (over the threshold of 171). For higher Reynolds numbers such as 7500 and 12000 the secondary flow diffuses to the interior of the duct where it assumes a fully developed configuration and the transition to the turbulence structure is observed. The Sobolev norms increase almost proportionally to the increase of the Reynolds number, and play an essential role for more complex problems involving transition to turbulence modelling. Copyright © 2002 John Wiley & Sons, Ltd.
A multi‐dimensional monotonic finite element model for solving the convection–diffusion‐reaction equation
Authors: Sheu Tony W. H. , Chen Harry Y. H.
Published: October 2002

In this paper, we develop a finite element model for solving the convection–diffusion‐reaction equation in two dimensions with an aim to enhance the scheme stability without compromising consistency. Reducing errors of false diffusion type is achieved by adding an artificial term to get rid of three leading mixed derivative terms in the Petrov–Galerkin formulation. The finite element model of the Petrov–Galerkin type, while maintaining convective stability, is modified to suppress oscillations about the sharp layer by employing the M‐matrix theory. To validate this monotonic model, we consider test problems which are amenable to analytic solutions. Good agreement is obtained with both one‐ and two‐dimensional problems, thus validating the method. Other problems suitable for benchmarking the proposed model are also investigated. Copyright © 2002 John Wiley & Sons, Ltd.
On streamline diffusion arising in Galerkin FEM with predictor/multi‐corrector time integration
Authors: Eguchi Yuzuru
Published: October 2002

In the present paper, the author shows that the predictor/multi‐corrector (PMC) time integration for the advection–diffusion equations induces numerical diffusivity acting only in the streamline direction, even though the equations are spatially discretized by the conventional Galerkin finite element method (GFEM). The transient 2‐D and 3‐D advection problems are solved with the PMC scheme using both the GFEM and the streamline upwind/Petrov Galerkin (SUPG) as the spatial discretization methods for comparison. The solutions of the SUPG‐PMC turned out to be overly diffusive due to the additional PMC streamline diffusion, while the solutions of the GFEM‐PMC were comparatively accurate without significant damping and phase error. A similar tendency was seen also in the quasi‐steady solutions to the incompressible viscous flow problems: 2‐D driven cavity flow and natural convection in a square cavity. Copyright © 2002 John Wiley & Sons, Ltd.
Stage‐specific gene expression in early differentiating oligodendrocytes
Authors: Blasi Francesca , Ciarrocchi Alessia , Luddi Alice , Strazza Michelina , Riccio Massimo , Santi Spartaco , Arcone Rosaria , Pietropaolo Concetta , D'Angelo Romina , Costantino‐Ceccarini Elvira , Melli Marialuisa
Published: October 2002

The screening of a differential library from precursor and differentiated oligodendrocytes, obtained through the representational difference analysis (RDA) technique, has generated a number of cDNA recombinants corresponding to mRNA coding for known and unknown proteins: (1) mRNA coding for proteins involved in protein synthesis, (2) mRNA coding for proteins involved in the organization of the cytoskeleton, and (3) mRNA coding for proteins of unknown function. The expression profile of the mRNA was studied by Northern blot hybridization to the poly‐A+ mRNA from primary rat progenitor and differentiated oligodendrocytes. In most cases, hybridization to the precursor was higher than hybridization to the differentiated mRNA, supporting the validity of the differential screening. Hybridization of the cDNA to rat cerebral hemisphere and brain stem poly‐A+ mRNA, isolated from 1‐ to 90‐day‐old rats, confirms the results obtained with the mRNA from differentiating oligodendrocytes. The intensity of the hybridization bands decreases as differentiation proceeds. The pattern of expression observed in oligodendrocytes is different from that found in the brain only in the case of the nexin‐1 mRNA, the level of which remains essentially constant throughout differentiation both in the brain stem and in the cerebral hemispheres, in agreement with the published data. In contrast, the intensity of hybridization to the oligodendrocyte mRNA is dramatically lower in the differentiated cells compared with the progenitor oligodendrocyte cells. Some of the recombinant cDNA represent mRNA sequences present at high frequency distribution in the cells, while others belong to the rare sequences group. Six recombinants code for proteins of the ribosomal family, suggesting that of approximately 70 known ribosomal proteins, only a few are upregulated during oligodendrocyte differentiation. The third category of open reading frame (ORF) is represented by rare messengers coding for proteins of unknown functions and includes six clones: RDA 279, 11, 95, 96, 254, and 288. GLIA 39:114–123, 2002. © 2002 Wiley‐Liss, Inc.
MHC class II‐positive perivascular microglial cells mediate resistance to Cryptococcus neoformans brain infection
Authors: Aguirre Karen , Miller Shannon
Published: October 2002

Acquired resistance to the CNS pathogen Cryptococcus neoformans is mediated by CD4+ T lymphocytes primed by exposure to antigen in the context of major histocompatibility class II (MHC II) molecules. In mouse brain, parenchymal and perivascular microglial cells may express interferon‐γ (IFN‐γ)‐inducible MHC class II marker and thus interact with CD4+ T cells. Primed effector T cells are retained in the infected CNS if antigen is encountered in proper MHC context and may deliver signals that potentiate microglia to enhanced fungistasis. Vaccinated C57BL6/J mice resist an ordinarily lethal C. neoformans rechallenge, but identically treated congenic Aβo/o mice (MHC class II‐deficient; CD4+ T‐cell‐deficient) do not. Nor can Aβo/o mice be adoptively immunized by infusion of lymphocytes from vaccinated C57BL6/J donors, as are severe combined immunodeficient (SCID) mice (MHC class II‐intact, lymphocyte‐deficient). Chimeric (C57BL/6J:Aβo/o) mice with class II expression likely on perivascular microglia only were, like SCID mice, capable of adoptive immunization against C. neoformans brain infection. To the contrary, chimeric mice with class II expression likely only on parenchymal microglia were not capable of effective adoptive immunization against C. neoformans brain infection. Therefore, in order to mediate resistance to infection, primed CD4+ T cells must interact with the replenishable perivascular microglial subset that lies in close proximity to cerebral vasculature. Although T cells may supply help in the form of inflammatory cytokines to parenchymal microglia, expression of class II on these cells appears unnecessary for antifungal activity. GLIA 39:184–188, 2002. © 2002 Wiley‐Liss, Inc.
Revealing a hidden problem. An evaluation of a community dementia case‐finding program from the Indian 10/66 dementia research network
Authors: Shaji K. S. , Arun Kishore N. R. , Lal K. Praveen , Prince Martin
Published: October 2002

Background

Dementia in India is largely a hidden problem with no community awareness and little help seeking from affected families, despite high levels of strain. Cases must therefore be identified before practical help can be offered.

Method

After two and a half hours of formal training, local community health workers in rural Kerala were asked to identify possible cases of dementia from the community they served. Diagnoses were then verified by a senior local psychiatrist with clinical and research interests in old age psychiatry.

Results

The community health workers identified 51 out of 1979 over 60 year old residents (a prevalence of 2.6%) as suspected cases of dementia. Following the psychiatrist's assessment, 33 met DSM‐IV criteria for dementia. The majority of confirmed cases were of the Alzheimer's Disease sub‐type. Most ‘non‐cases’ were found to be suffering from other major psychiatric disorders, with substantial unmet need. The positive predictive value of the community health workers informal screening was 64.7%.

Conclusions

This simple cost‐effective case‐finding method can be of practical use in the development of community based dementia care services in India and other developing countries with similar health care systems. Copyright © 2002 John Wiley & Sons, Ltd.
Data management and quality assurance for an International project: the Indo–US Cross‐National Dementia Epidemiology Study
Authors: Pandav Rajesh , Mehta Arun , Belle Steven H. , Martin Deborah E. , Chandra Vijay , Dodge Hiroko H. , Ganguli Mary
Published: October 2002

Background

Data management and quality assurance play a vital but often neglected role in ensuring high quality research, particularly in collaborative and international studies.

Objective

A data management and quality assurance program was set up for a cross‐national epidemiological study of Alzheimer's disease, with centers in India and the United States.

Methods

The study involved (a) the development of instruments for the assessment of elderly illiterate Hindi‐speaking individuals; and (b) the use of those instruments to carry out an epidemiological study in a population‐based cohort of over 5000 persons. Responsibility for data management and quality assurance was shared between the two sites. A cooperative system was instituted for forms and edit development, data entry, checking, transmission, and further checking to ensure that quality data were available for timely analysis. A quality control software program (CHECKS) was written expressly for this project to ensure the highest possible level of data integrity.

Conclusions

This report addresses issues particularly relevant to data management and quality assurance at developing country sites, and to collaborations between sites in developed and developing countries. Copyright © 2002 John Wiley & Sons, Ltd.
Personality traits and socio‐epidemiological status of hospitalised elderly benzodiazepine users
Authors: Petrovic Mirko , Vandierendonck Andre , Mariman Ann , van Maele Georges , Afschrift Marcel , Pevernagie Dirk
Published: October 2002

Objective

To define personality traits and socio‐epidemiological status of hospitalised elderly chronic benzodiazepine (BZD) users.

Methods

This case controlled study assessed psychological characteristics (using the Millon Clinical Multiaxial Inventory—MCMI‐I) and socio‐epidemiological status (sex, age, education, marital status and housing) in 40 hospitalised geriatric patients taking BZDs for at least 3 months and 40 non‐users, excluding dementia.

Results

Comparisons between groups: Compulsive personality pattern was more pronounced in the control group (p = 0.008). Severe personality pathology: a predisposition to borderline disorder was stronger among the BZD‐users (p = 0.001). Clinical syndromes: anxiety, dysthymic disorder (p < 0.001) and tendency to alcohol dependence (p = 0.020) prevailed in the BZD‐users. No severe syndromes were found. Widowed persons were more prevalent between the BZD‐users (p = 0.03). All significant differences resulted from disparities between females. Predictors of BZD‐use and clustering of traits: Dysthymic disorder was predictive of BZD‐use (odds ratio (OR) 6.3 [95% confidence intervals (CI) 2.2–18.2]). It was strongly correlated with anxiety (rs = 0.93) and somatoform disorder (rs = 0.71). Dysthymic disorder and alcohol dependence predicted BZD‐use in women (OR 15.3 [CI: 2.4–95.7] and OR 9.1 [CI: 1.2–64.9], respectively). There were no specific predictors in men.

Conclusions

Chronic elderly BZD‐users are typically widowed females with dysthymic disorder, anxiety, predisposition to alcohol dependence and borderline disorder. Before prescribing BZDs, it is important to recognize the nature of the elderly population at risk for BZD‐use and to consider a broader‐ranging therapeutic management of the predisposing personality traits. Copyright © 2002 John Wiley & Sons, Ltd.
“Tongue sandwich” bolster for skin graft immobilization
Authors: Butler Charles E.
Published: October 2002

Background

Because of surface irregularities and continuous movement of the tongue, predictable immobilization of split‐thickness skin grafts (STSGs) for tongue defects is difficult to achieve.

Methods

A novel composite, bilayer foam bolster was used to immobilize a STSG after reconstruction of more than 80% of the tongue mucosa after resection of a squamous cell carcinoma and extensive leukoplakia. Dorsal and ventral bolster components were placed over the STSG and affixed using transglossal, through‐and‐through sutures.

Results

The composite foam bolster provided uniform compression along the highly irregular and mobile skin‐grafted surface. Graft survival was excellent, and there were no complications.

Conclusions

The “tongue sandwich” bolster is quickly and easily fabricated, immobilizes the tongue in a fully expanded position, and provides excellent apposition of STSGs to highly irregular and vascular surfaces. © 2002 Wiley Periodicals, Inc. Head Neck 24: 705–709, 2002
“FAR” chemoradiotherapy improves laryngeal preservation rates in patients with T2N0 glottic carcinoma
Authors: Kumamoto Yoshihiko , Masuda Muneyuki , Kuratomi Yuichiro , Toh Satoshi , Shinokuma Atsushi , Chujo Kyoko , Yamamoto Tomoya , Komiyama Sohtaro
Published: October 2002

Background

The appropriate treatment approach for patients with T2N0 laryngeal cancer remains highly controversial. Because radiotherapy alone is associated with a high risk of local recurrence, we have developed a triple combination treatment approach consisting of 5‐fluorouracil (250 mg/day, i.v.), vitamin A (50,000 unit/day, i.m.) and external radiation (2.0 Gy/day), which we have termed “FAR therapy.”

Methods

Patients with T2N0 glottic carcinoma were initially treated with 15 days of FAR therapy, which included a cumulative radiation dose of 30Gy (i.e., “30 Gy of FAR therapy”). Those patients who demonstrated a complete response either clinically or pathologically continued to receive further FAR therapy, with up to 60–70 Gy. All other patients received laryngectomy without any additional treatment.

Results

Ninety‐five patients were treated according to this program, and most of the patients (98%) were able to complete this treatment course. Eighty‐eight patients (93%) were treated with FAR therapy alone. The local control and ultimate local control rates were 91% (85 of 93), and 99% (92 of 93), respectively. The cumulative 5‐year voice preservation and complete laryngeal preservation rates were 91% and 87%, respectively. The cumulative 5‐year disease‐specific survival rate was 97%.

Conclusions

Because a high rate of laryngeal preservation was achieved without compromising disease‐specific survival, our treatment approach based on FAR therapy may be promising for the treatment of patients with T2N0 glottic carcinoma. © 2002 Wiley Periodicals, Inc.
Tetanic stimulation of Schaffer collaterals induces rhythmic bursts via NMDA receptor activation in rat CA1 pyramidal neurons
Authors: Bonansco Christian , González de la Vega Alberto , González Alegre Pedro , Borde Michel , García‐Segura Luis M. , Buño Washington
Published: October 2002

Exploring the principles that regulate rhythmic membrane potential (Vm) oscillations and bursts in hippocampal CA1 pyramidal neurons is essential to understanding the θ rhythm (θ). Recordings were performed in vitro in hippocampal slices from young rats, and a group of the recorded CA1 pyramidal cells were dye‐filled with carboxifluorescein and immunolabeled for the R1 subunit of the NMDA receptor. Tetanic stimulation of Schaffer collaterals (SCs) and iontophoresis of glutamate evoked rhythmic Vm oscillations and bursts (≈10 mV, ≈7 Hz, 2–5 spikes per burst) in cells (31%) placed close to the midline (“medial cells”). Rhythmic bursts remained under picrotoxin (10 μM) and Vm oscillations persisted with tetrodotoxin (1.5 μM), but bursts were blocked by AP5 (25 μM) and Mg2+‐free solutions. Depolarization and AMPA never induced rhythmic bursts. The rest of the neurons (69%), recorded closer to the CA3 region (“lateral cells”), discharged rhythmically single repetitive spikes under SC stimulation and glutamate in control conditions, but fired rhythmic bursts under similar stimulation, both when NMDA was applied and when non‐NMDA receptors were blocked with CNQX (20 μM). Medial cells exhibited a larger NMDA current component and a higher NMDAR1 density at the apical dendritic shafts than lateral cells, suggesting that these differences underlie the dissimilar responses of both cell groups. We conclude that the “θ‐like” rhythmic oscillations and bursts induced by glutamate and SC stimulation relied on the activation of NMDA receptors at the apical dendrites of medial cells. These results suggest a role of CA3 pyramidal neurons in the generation of CA1 θ via the activation of NMDA receptors of CA1 pyramidal neurons. Hippocampus 2002;12:434–446. © 2002 Wiley‐Liss, Inc.
Telemetry system for reliable recording of action potentials from freely moving rats
Authors: Hawley Emerson S. , Hargreaves Eric L. , Kubie John L. , Rivard Bruno , Muller Robert U.
Published: October 2002

Recording single cells from alert rats currently requires a cable to connect brain electrodes to the acquisition system. If no cable were necessary, a variety of interesting experiments would become possible, and the design of other experiments would be simplified. To eliminate the need for a cable we have developed a one‐channel radiotelemetry system that is easily carried by a rat. This system transmits a signal that is reliable, highly accurate and can be detected over distances of ≥20 m. The mobile part of the system has three components: (1) a headstage with built‐in amplifiers that plugs into the connector for the electrode array on the rat's head; the headstage also incorporates a light‐emitting diode (LED) used to track the rat's position; (2) a backpack that contains the transmitter and batteries (2 N cells); the backpack also provides additional amplification of the single cell signals; and (3) a short cable that connects the headstage to the backpack; the cable supplies power to the headstage amplifiers and the LED, and carries the physiological signals from the headstage to the backpack. By using a differential amplifier and recording between two brain microelectrodes the system can transmit action potential activity from two nearly independent sources. In a future improvement, two transmitters with different frequencies would be used to telemeter signals from four microelectrodes simultaneously. Hippocampus 2002;12:505–513. © 2002 Wiley‐Liss, Inc.
An investigation of vapor concentration during boiling of a liquid mixture: Measurement of temperature and concentration variations of vapor in bubbles
Authors: Utaka Yoshio , Sai Seikou
Published: October 2002

Variations of the vapor concentration of a water‐ethanol mixture during saturated nucleate pool boiling were studied. The temperature changes of the vapor in bubbles produced by the boiling were measured at several different positions near the boiling surface by using a thin thermocouple having high responsivity. The superheat of the bubbles was initially higher in the superheated liquid layer near the heat transfer surface and then approached the bulk temperature along the upward direction. It was clarified that the temperature and concentration differences of the bubbles from the bulk almost disappeared at a height of 3 to 5 mm from the heat transfer surface and within 20 ms after the appearance of the bubbles. Thus, the former result of the liquid‐vapor equilibrium with the bulk condition was confirmed. © 2002 Wiley Periodicals, Inc. Heat Trans Asian Res, 31(6): 475–485, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.10047
Saccadic peak velocity and EEG as end‐points for a serotonergic challenge test
Authors: Gijsman Harm J. , van Gerven Joop M. A. , Verkes Robbert Jan , Schoemaker Rik C. , Pieters Monique S. M. , Pennings Ed J. M. , Hessing Trees J. , Cohen Adam F.
Published: October 2002

We previously reported that a single dose of the serotonin receptor agonist meta‐chlorophenylpiperazine increased the peak velocity of saccadic eye movements and decreased low‐frequency electroencephalographic activity.

Methods

We administered a single dose of the serotonin releaser dexfenfluramine in a double blind, placebo controlled randomised cross‐over design and measured saccadic eye movements and EEG every hour up to 6 h. Subjects were 62 males (18–30 years) with a history of no, moderate or heavy use of ecstasy tablets.

Results

Dexfenfluramine increased saccadic peak velocity and decreased alpha, delta and theta electroencephalographic activity, the latter predominantly in heavy users of ecstasy.

Conclusions

This study supports the idea that saccadic peak velocity and EEG can be useful endpoints of a serotonergic challenge. This could be an important anatomical extension of these end‐points, which until now were limited to the effect on hypothalamic serotonergic projections. Copyright © 2002 John Wiley & Sons, Ltd.
Tianeptine and fluoxetine in major depression: a 6‐week randomised double‐blind study
Authors: Novotny Vladimir , Faltus Frantisek
Published: October 2002

In a 6‐week, multicentre, randomised, double‐blind controlled study, tianeptine (37.5 mg/day) and fluoxetine (20 mg/day) were compared for efficacy and safety in 178 patients with major depression. No significant difference was shown between the two drugs, either in terms of efficacy (MADRS, CGI, COVI) or in terms of safety, except for the CGI ‘severity of illness’ which was lower at the end point with tianeptine than with fluoxetine. The percentages of responders (as defined by a 50% decrease of the MADRS score from baseline to end point) were 75% with tianeptine and 67% with fluoxetine, showing the efficacy of both drugs. In conclusion, both tianeptine and fluoxetine are effective and well‐tolerated treatments for major depression. Copyright © 2002 John Wiley & Sons, Ltd.
Lag prediction in ungauged basins: an investigation through actual data of the upper Tiber River valley
Authors: Melone F. , Corradini C. , Singh V. P.
Published: October 2002

A comparative analysis of a variety of relationships for prediction of basin lag is performed by applying them to 23 basins located in the same geographical area and characterized by a rather similar vegetative cover. The results of computations indicate that a lag–area relationship with two constant parameters is the best predictor for most basins; under different vegetative covers in the same basin only one parameter should be variable. For a few other basins characterized by an anomalous drainage channel network of low density, such a relationship can lead to unacceptable errors. Thus, there is a need for an additional relationship to overcome this difficulty, but a larger number of anomalous basins would be required for its determination. An alternative procedure, based on the use of the non‐linear kinematic wave, which at least allows singling out the cases where a specific lag–area relationship is not reliable, is proposed. This procedure, therefore, represents a partial but very useful solution to avoid considerable errors in hydrological practice. Copyright © 2002 John Wiley & Sons, Ltd.