bluuebunny/crossref_metadata_2025 huggingface dataset:
Feature‐space clustering for fMRI meta‐analysis
Authors: Goutte Cyril , Hansen Lars Kai , Liptrot Matthew G. , Rostrup Egill
Published: August 2002

Clustering functional magnetic resonance imaging (fMRI) time series has emerged in recent years as a possible alternative to parametric modeling approaches. Most of the work so far has been concerned with clustering raw time series. In this contribution we investigate the applicability of a clustering method applied to features extracted from the data. This approach is extremely versatile and encompasses previously published results [Goutte et al.,1999] as special cases. A typical application is in data reduction: as the increase in temporal resolution of fMRI experiments routinely yields fMRI sequences containing several hundreds of images, it is sometimes necessary to invoke feature extraction to reduce the dimensionality of the data space. A second interesting application is in the meta‐analysis of fMRI experiment, where features are obtained from a possibly large number of single‐voxel analyses. In particular this allows the checking of the differences and agreements between different methods of analysis. Both approaches are illustrated on a fMRI data set involving visual stimulation, and we show that the feature space clustering approach yields nontrivial results and, in particular, shows interesting differences between individual voxel analysis performed with traditional methods. Hum. Brain Mapping 13:165–183, 2001. © 2001 Wiley‐Liss, Inc.
Fast realistic modeling in bioelectromagnetism using lead‐field interpolation
Authors: Yvert Blaise , Crouzeix‐Cheylus Anne , Pernier Jacques
Published: August 2002

The practical use of realistic models in bioelectromagnetism is limited by the time‐consuming amount of numerical calculations. We propose a method leading to much higher speed than currently available, and compatible with any kind of numerical methods (boundary elements (BEM), finite elements, finite differences). Illustrated with the BEM for EEG and MEG, it applies to ECG and MCG as well. The principle is two‐fold. First, a Lead‐Field matrix is calculated (once for all) for a grid of dipoles covering the brain volume. Second, any forward solution is interpolated from the pre‐calculated Lead‐Fields corresponding to grid dipoles near the source. Extrapolation is used for shallow sources falling outside the grid. Three interpolation techniques were tested: trilinear, second‐order Bézier (Bernstein polynomials), and 3D spline. The trilinear interpolation yielded the highest speed gain, with factors better than ×10,000 for a 9,000‐triangle BEM model. More accurate results could be obtained with the Bézier interpolation (speed gain ∼1,000), which, combined with a 8‐mm step grid, lead to intrinsic localization and orientation errors of only 0.2 mm and 0.2 degrees. Further improvements in MEG could be obtained by interpolating only the contribution of secondary currents. Cropping grids by removing shallow points lead to a much better estimation of the dipole orientation in EEG than when solving the forward problem classically, providing an efficient alternative to locally refined models. This method would show special usefulness when combining realistic models with stochastic inverse procedures (simulated annealing, genetic algorithms) requiring many forward calculations. Hum. Brain Mapping 14:48–63, 2001. © 2001 Wiley‐Liss, Inc.
Methyl and dimethyl derivatives of tetrathionaphthalene and tetraselenonaphthalene as novel electron donors
Authors: Kodama Takashi , Kodani Mie , Takimiya Kazuo , Aso Yoshio , Otsubo Tetsuo
Published: August 2002

Monomethyl and dimethyl tetrathionaphthalenes and tetraselenonaphthalenes have been developed as modified electron donors. Introduction of methyl groups is very helpful in enhancing the inherent low solubilities of the parent compounds. In the cyclic voltammograms, they show two reversible redox waves, whose first and second oxidation potentials are gradually lowered with the increasing number of the introduced methyl groups. They all are able to form charge‐transfer complexes with tetracyanoquinodimethane. Irrespective of the chalcogen kind of the donor, the complexes of the dimethyl derivatives are conductive, while those of the monomethyl derivatives are insulating. The different conductivities are explained by the difference of their crystal structures, which are studied by infrared spectroscopy. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:287–292, 2001
Syntheses and reactions of cyclic se‐alkoxy‐se‐chloroselenuranes and alkoxyselenonium salts
Authors: Kataoka Tadashi , Iwamura Tatsunori , Tsutsui Hisayoshi , Kato Yasuharu , Banno Yoshihiro , Aoyama Yasuko , Shimizu Hiroshi
Published: August 2002

Several 1‐chloro‐2,1‐oxaselenole selenuranes 3a–e and selenonium salts 4a–c and 5‐chloro‐5,11‐epoxy‐6,11‐dihydrodibenzo[b,e]selenepines 12a and 12b and selenonium salts 13a–c were synthesized, and their reactions with organometallic reagents were studied. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:317–326, 2001
New methods of synthesis of boron, germanium, and tin derivatives of pentavalent phosphorus thioacids
Authors: Nizamov Il'yas S. , Sorokina Tat'yana P. , Nizamov Il'nar D. , Galimullina Nailya G. , Batyeva Elvira S. , Alfonsov Vladimir A.
Published: August 2002

The reactions of S‐trimethylsilyl esters of S‐propyl‐4‐methoxyphenyltrithiophosphonic, bis(dialkylamido)dithiophosphoric, and S‐ethyl‐diethylamidotrithiophosphoric acids with trialkyl borates, triorganylbromogermanes, trimethyl(isobutylthio)germane, and trialkylchlorostannanes were studied. On the basis of these studies, new methods of synthesizing S‐boron, S‐germyl, and S‐stannyl derivatives of pentavalent phosphorus thioacids were developed. S‐Diethylaminomethyl O‐isopropyl‐4‐ethoxyphenyldithiophosphonate was obtained by the reaction of the diisopropylboron derivative of the corresponding dithiophosphonic acid with the aminal 6. © 2002 John Wiley & Sons, Inc. Heteroatom Chem 13:27–35, 2002; DOI 10.1002/hc.1103
Metastatic cancer to the floor of mouth: the lingual lymph nodes
Authors: Dutton Jay M. , Graham Scott M. , Hoffman Henry T.
Published: August 2002

Background

The upper level of a cervical lymphadenectomy is anatomically defined at its anterior extent by the lower border of the mandible and, in surgical practice, by the lingual nerve. A neck dissection completed below this level is generally considered adequate for removal of lymph nodes at risk for metastases from oral cavity cancer. Traditional discontinuous neck dissections do not provide for removal of floor of mouth tissue along with the primary and neck specimens.

Methods

A case report presenting biopsies from a T2N2bM0 squamous cell carcinoma of the mobile tongue and adjacent floor of the mouth in a 73‐year‐old man.

Results

Deep biopsy of a ventral tongue and floor of mouth squamous cell carcinoma revealed occult metastatic cancer to lymph nodes located in the superficial floor of mouth associated with the sublingual gland above the lingual nerve. This report identifies floor of mouth lymph nodes that can be involved with cancer and missed through the standard practice of discontinuous neck dissection.Conclusions. This finding offers evidence that, in certain cases, a traditional discontinuous neck dissection may not address all lymph nodes at risk in the treatment of oral cavity cancer. Further investigation into lymph node distribution within the oral cavity is warranted to reappraise the upper limits of cervical lymphadenectomy. © 2002 Wiley Periodicals, Inc. Head Neck 24: 401–405, 2002; DOI 10.1002/hed.10026
Geostatistical regional trend detection in river flow data
Authors: Adamowski Kaz , Bocci Cynthia
Published: August 2002

Many studies have identified global warming and climate change as some of the biggest challenges facing Canada. In this paper, the regional temporal trend in river flows is investigated using a space–time model. Though the primary focus is the time component, the spatial relationship among monitoring stations in a region is used to develop a space–time model that is composed of a random time trend as a function of space, and a random error term as a function of both time and space. The estimate of regional time trend is a linear combination of the differenced observations that minimizes the variance of estimated errors.

Data from 248 river stations in the Reference Hydrometric Basin Network (RHBN) established by Environment Canada is analysed. These hydrological monitoring stations are grouped into ten non‐overlapping homogeneous regions covering all of Canada. An estimate of trend, along with its variance, is calculated for each region. Some significant trends are found for the annual mean, maximum and minimum flows, as well as for the mean monthly flows for July and December, and are consistent with those detected in other Canadian studies. Copyright © 2001 John Wiley & Sons, Ltd.
Two metachronous tumors in the radiotherapy fields of a patient with Li‐Fraumeni syndrome
Authors: Limacher Jean‐Marc , Frebourg Thierry , Natarajan‐Ame Shanti , Bergerat Jean‐Pierre
Published: August 2002

A woman with a family history of brain tumors in her daughter and sister presented with a breast cancer. She subsequently developed two metachronous primary tumors: a small‐cell lung cancer and a colon carcinoma. These tumors arose within the internal mammary radiotherapy field and within the field irradiated for ovariolysis. The p53 gene was analyzed in whole blood lymphocytes using a functional assay developed in yeastSaccharomyces cerevisiae,which tests the transcriptional competence of p53. DNA from the colon cancer cells was analyzed by polymerase chain reaction and sequencing. The patient had a germline‐inactivating p53 mutation, confirming the diagnosis of Li‐Fraumeni syndrome (LFS). The colon tumor and the lung tumor both conserved the mutant p53 allele but had lost the wild‐type allele. This observation and the experimental data suggest an abnormal sensitivity of LFS patients to radiogenic carcinogenesis. The indications and extent of radiotherapy in patients with a clinical or molecular diagnosis of LFS should be discussed individually and should take into account the risk of secondary neoplasms arising in the radiation fields. © 2001 Wiley‐Liss, Inc.
Osteopontin induces angiogenesis of murine neuroblastoma cells in mice
Authors: Takahashi Fumiyuki , Akutagawa Shigeru , Fukumoto Hisao , Tsukiyama Shoji , Ohe Yuichiro , Takahashi Kazuhisa , Fukuchi Yoshinosuke , Saijo Nagahiro , Nishio Kazuto
Published: August 2002

Angiogenesis is an essential process for tumor growth and is regulated by tumor‐derived angiogenic cytokines. Osteopontin (OPN) is one of the cytokines produced by various tumor cells and is suggested to be involved in angiogenesis by upregulating endothelial cell migration in cooperation with vascular endothelial cell growth factor (VEGF). To provide evidence of OPN involvement in a causal role in tumor angiogenesis, we generated a stable transfectant from murine neuroblastoma C1300 cells to constitutively secrete high levels of murine OPN. The OPN mRNA expression and protein secretion were confirmed by RT‐PCR and ELISA, respectively. The biological activity of secreted OPN was determined with migration assay by using human umbilical vein endothelial cells (HUVEC). Transfection with OPN gene did not increase VEGF production and did not affect gene expression of other angiogenic factors confirmed by complementary DNA macroarray system. To demonstrate the effect of OPN on tumor‐induced angiogenesis in vivo, millipore chambers containing OPN‐transfected or control cells were implanted to the dorsal air sac of mice. The OPN‐transfected cells significantly induced neovascularization in comparison to the control cells in mice. Conclusively, these results provide direct evidence of OPN involvement in the role of tumor angiogenesis. © 2002 Wiley‐Liss, Inc.
CD40 ligation downregulates EBNA‐2 and LMP‐1 expression in EBV‐transformed lymphoblastoid cell lines
Authors: Pokrovskaja Katja , Ehlin‐Henriksson Barbro , Kiss Csaba , Challa Anita , Gordon John , Gogolak Peter , Klein George , Szekely Laszlo
Published: August 2002

Epstein‐Barr virus (EBV) drives the proliferation of human B cells in vitro and during primary infection in vivo. The transformed immunoblasts express nuclear proteins EBNA1–6, transcribed from the Cp/Wp promoter, and the membrane proteins LMP‐1, ‐2A and ‐2B (lymphoblastoid type of latency). EBV persists through life in resting memory B cells with a restricted type of latency in the absence of the Cp/Wp promoter activity. Since CD40 crosslinking can reportedly inhibit the growth of EBV‐transformed lymphoblastoid cell lines (LCLs), we have examined the effect of CD40 ligation on the expression of EBNAs and LMP‐1 and on Cp EBV promoter activity together with several phenotypic markers. CD40 crosslinking led to a partial downregulation of EBNA‐2, EBNA3–6 and LMP‐1 in LCLs, paralleled by downregulation of Cp promoter activity. It also induced upregulation of the germinal center marker CD77 on the LCL cells. Our findings suggest that the encounter of proliferating EBV‐transformed immunoblasts with CD40L, as would occur when normal B cells generate memory cells in germinal centers, may switch the viral transcription program from the full lymphoblastoid to a more restricted latency program in a proportion of cells. This would permit virus persistence in the B‐cell memory compartment. © 2002 Wiley‐Liss, Inc.
Involvement of phosphorylation of tyr‐31 and tyr‐118 of paxillin in MM1 cancer cell migration
Authors: Iwasaki Teruo , Nakata Atsushi , Mukai Mutsuko , Shinkai Kiyoko , Yano Hajime , Sabe Hisataka , Schaefer Erik , Tatsuta Masaharu , Tsujimura Tohru , Terada Nobuyuki , Kakishita Eizo , Akedo Hitoshi
Published: August 2002

We demonstrated previously that rat ascites hepatoma MM1 cells require both lysophosphatidic acid (LPA) and fibronectin (FN) for phagokinetic motility and transcellular migration and that these events are regulated through the RhoA‐ROCK pathway. It remains to be elucidated, however, how the signals from both LPA and FN are integrated into cell migration. To examine this, total cellular lysates after stimulation with LPA or FN were subjected to time‐course immunoblot analysis with anti‐phosphotyrosine antibodies (Abs). Consequently, tyrosine‐phosphorylation of paxillin was obviously persistent after stimulation with FN + LPA as compared to after stimulation with either alone. Tyrosine‐phosphorylated paxillin comprised 2 components; slowly and fast migrating ones. Immunoblotting of anti‐paxillin immunoprecipitates with phosphorylation site‐specific Abs revealed the following: tyrosine‐phosphorylation was enhanced preferentially on a slowly migrating component after stimulation with FN + LPA; this component contained phosphorylation at both tyrosine residue (Y) 31 and Y118; and phosphorylation of paxillin at Y181 was constitutive and not augmented by stimulation with either FN or LPA. Amiloride, an inhibitor of the Na+/H+ antiporter downstream of ROCK, suppressed cell motility and correspondingly paxillin tyrosine‐phosphorylation at both Y31 and Y118. Paxillin phosphorylation weakly induced by FN alone, insufficient for cell migration, was not inhibited by amiloride. These results demonstrate that LPA collaborates with FN for persistent tyrosine phosphorylation of paxillin at both Y31 and Y118, regulated by the Na+/H+ antiporter downstream of ROCK and that this phosphorylated paxillin is essential for MM1 cancer cell migration. © 2001 Wiley‐Liss, Inc.
Investigating the effects of employment‐housing change on migration: evidence from Japan
Authors: Portnov Boris A. , Kim Doo‐Chul , Ishikawa Yoshitaka
Published: August 2002

The effect of employment growth on internal migration depends on corresponding adjustments of the local housing market. If employment growth in a geographical area is accompanied by a sharp increase in housing prices, the net outcome may be net out‐migration rather than migration gain. In the present paper, this concept is tested using statistical data available for 47 prefectures in Japan. The analysis covers the two five‐year periods of 1983–87 and 1988–92, and confirms that the use of a combined representation of employment and housing variables makes it possible to improve considerably the performance of an empirical migration model. Copyright © 2001 John Wiley & Sons, Ltd.
Modulation of marrow stromal osteoblast adhesion on biomimetic oligo[poly(ethylene glycol) fumarate] hydrogels modified with Arg‐Gly‐Asp peptides and a poly(ethylene glycol) spacer
Authors: Shin Heungsoo , Jo Seongbong , Mikos Antonios G.
Published: August 2002

Novel oligo[poly(ethylene glycol) fumarate] (OPF) hydrogels functionalized with cell adhesion peptides were prepared, and the effects of incorporated peptide density and macromolecular structure of hydrogels on attachment and morphology of marrow stromal cells (MSCs) were evaluated. Poly(ethylene glycol) (PEG; number average molecular weight of 930, 2860, and 6090) was used to synthesize OPF. A model peptide, Gly‐Arg‐Gly‐Asp (GRGD), was incorporated into OPF hydrogels after being coupled to acrylated PEG of molecular weight 3400. The increase of incorporated peptide concentration enhanced MSC attachment to OPF hydrogels of PEG of molecular weight of 930 and 2860. However, the number of attached MSCs to OPF hydrogels of PEG (molecular weight 6090) remained constant regardless of the peptide density. The length of PEG in OPF also influenced cell attachment. When 1 μmole peptide/g hydrogel was incorporated into the OPF hydrogels, the degree of cell attachment at 12 h relative to the initial seeding density was 93.9 ± 5.9%, 64.7 ± 8.2%, and 9.3 ± 6.6% for OPF hydrogels prepared with PEG of molecular weights of 930, 2860, and 6090, respectively. However, the crosslinking density of hydrogels did not significantly affect cell attachment. The interaction was sequence specific, in that MSC attachment to GRGD‐modified hydrogels was competitively inhibited when cells were incubated in the presence of 0.5 mM soluble GRGD before cell seeding. These results suggest that we can modulate MSC attachment to OPF hydrogels by altering the peptide density and the molecular structure of OPF hydrogels. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 61: 169–179, 2002
PU.1 regulates the expression of the Vav proto‐oncogene
Authors: Denkinger Diane J. , Lambrecht Taryn Q. , Cushman‐Vokoun Allison M. , Kawahara Rodney S.
Published: August 2002

Vav is a guanine nucleotide exchange factor for the rho/rac GTPases that is upregulated in the embryo during the transition from primitive to definitive hematopoiesis. It is one of several genetic markers that correlates with the differentiation of the intraembryonic definitive hematopoietic stem cell. Subsequently, in the adult, vav is expressed predominantly in cells of the hematopoietic system. A heat‐resistant protein complex that bound to a 23‐bp segment, which is essential for vav promoter activity, was found to be present in myeloid cells but not T‐cells. The complex was absent in non‐hematopoietic cells which normally do not express vav. Using a saturation mutagenesis method, Mutex, a “footprint” of the protein binding site (AGAGGAAGT) was obtained that was consistent with the consensus binding site for PU.1. A specific antibody to PU.1 supershifted the complex and identified the presence of PU.1 within the complex. A GST fusion protein of the human PU.1 bound to the same consensus sequence as the heat‐resistant complex from myeloid lineages. Specific mutation of the GGAA PU.1 core binding site silenced vav promoter activity and a dominant negative PU.1 inhibited the transactivation of PU.1 at the vav promoter as measured by the expression of the EGFP reporter gene. In addition, PCR analysis of immunoprecipitated chromatin using specific antibodies for PU.1 detected the co‐immunoprecipitation of DNA containing the vav promoter. These results suggest that PU.1 is essential for transcriptional activity of the vav promoter in myeloid cells. J. Cell. Biochem. 84: 772–783, 2002. © 2002 Wiley‐Liss, Inc.
Adenovirus‐mediated BMP2 expression in human bone marrow stromal cells
Authors: Olmsted Elizabeth A. , Blum Jeremy S. , Rill Donna , Yotnda Patricia , Gugala Zbigniew , Lindsey Ronald W. , Davis Alan R.
Published: August 2002

Recombinant adenoviral vectors have been shown to be potential new tools for a variety of musculoskeletal defects. Much emphasis in the field of orthopedic research has been placed on developing systems for the production of bone. This study aims to determine the necessary conditions for sustained production of high levels of active bone morphogenetic protein 2 (BMP2) using a recombinant adenovirus type 5 (Ad5BMP2) capable of eliciting BMP2 synthesis upon infection and to evaluate the consequences for osteoprogenitor cells. The results indicate that high levels (144 ng/ml) of BMP2 can be produced in non‐osteoprogenitor cells (A549 cell line) by this method and the resultant protein appears to be three times more biologically active than the recombinant protein. Surprisingly, similar levels of BMP2 expression could not be achieved after transduction with Ad5BMP2 of either human bone marrow stromal cells or the mouse bone marrow stromal cell line W20‐17. However, human bone marrow stromal cells cultured with 1 μM dexamethasone for four days, or further stimulated to become osteoblast‐like cells with 50 μg/ml ascorbic acid, produced high levels of BMP2 upon Ad5BMP2 infection as compared to the undifferentiated cells. The increased production of BMP2 in adenovirus transduced cells following exposure to 1 μM dexamethasone was reduced if the cells were not given 50 μg/ml ascorbic acid. When bone marrow stromal cells were allowed to become confluent in culture prior to differentiation, BMP2 production in response to Ad5BMP2 infection was lost entirely. Furthermore, the increase in BMP2 synthesis seen during differentiation was greatly decreased when Ad5BMP2 was administered prior to dexamethasone treatment. In short, the efficiency of adenovirus mediated expression of BMP2 in bone marrow stromal cells appears to be dependent on the differentiation state of these cells. J. Cell. Biochem. 82: 11–21, 2001. © 2001 Wiley‐Liss, Inc.
Restrained point‐charge models for disaccharides
Authors: Sigfridsson Emma , Ryde Ulf , Bush Bruce L.
Published: August 2002

Various methods for deriving atomic partial charges from the quantum chemical electrostatic potential and moments have been tested for the sucrose molecule. We show that if no further information is used, the charges on some carbon atoms become large and charge patterns involving these atoms are badly determined and poorly transferable. Adding lone‐pairs on the ether oxygen atoms or dividing the molecule into smaller fragments did not cure the instabilities. We develop a method, CHELP‐BOW0, that restrains charges toward zero with different weights for different atoms. These harmonic restraints preserve the linear form of the least‐squares equations, which are solved in a single step using singular‐value decomposition. CHELP‐BOW0 improves the chemical transferability of the charges compared to unrestrained methods, and slightly improves their conformational transferability. It introduces a modest degradation of the fit compared to unrestrained CHELP‐BOW (mean average deviation of the potential 0.00016 vs. 0.00010 a.u.). A second new method, CHELP‐BOWC, avoids the need for restraints by including several conformations in the fit, weighting each according to its estimated energy in solution. CHELP‐BOWC charges are more transferable than CHELP‐BOW or CHELP‐BOW0 charges to conformations not included in the training set. Restraints to zero charge do not further improve transferability of the CHELP‐BOWC charges. We, therefore, recommend CHELP‐BOW charges for rigid molecules and CHELP‐BOWC charges for flexible molecules. © 2002 Wiley Periodicals, Inc. J Comput Chem 23: 351–364, 2002
Massive docking of flexible ligands using environmental niches in parallelized genetic algorithms
Authors: Thormann Michael , Pons Miquel
Published: August 2002

Virtual screening of large libraries of small compounds requires fast and reliable automatic docking methods. In this article we present a parallel implementation of a genetic algorithm (GA) and the implementation of an enhanced genetic algorithm (EGA) with niching that lead to remarkable speedups compared to the original version AutoDock 3.0. The niching concept is introduced naturally by sharing genetic information between evolutions of subpopulations that run independently, each on one CPU. A unique set of additionally introduced search parameters that control this information flow has been obtained for drug‐like molecules based on the detailed study of three test cases of different complexity. The average docking time for one compound is of 8.6 s using eight R10,000 processors running at 200 MHz in an Origin 2000 computer. Different genetic algorithms with and without local search (LS) have been compared on an equal workload basis showing EGA/LS to be superior over all alternatives because it finds lower energy solutions faster and more often, particularly for high dimensionality problems. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 1971–1982, 2001
Involvement of transcriptional repressor ATF3 in acceleration of caspase protease activation during DNA damaging agent‐induced apoptosis
Authors: Mashima Tetsuo , Udagawa Sachiko , Tsuruo Takashi
Published: August 2002

DNA topoisomerase inhibitors are effective chemotherapeutic agents on several solid tumor cells. They induce a specific signaling cascade that executes an active cell death process (apoptosis), including caspase activation, and the blockage of the signaling is associated with drug‐resistance of tumor cells. However, little is known about the initial signal transduction induced by the agents. In the present study, we screened genes that are initially upregulated in caspase‐independent manner. We found that the activating transcription factor 3 (ATF3) protein, a repressor of cyclic‐AMP responsive element (CRE)‐dependent transcription, was strongly induced among CRE‐BP/ATF members and subsequently accumulated in nuclei following camptothecin or etoposide treatment. During induction of apoptosis, the accumulation and the nuclear translocation of ATF3 coincided with the activation of caspase protease and were not inhibited by the broad caspase inhibitor Z‐VAD‐fmk, indicating that ATF3 induction is not a downstream event of caspase activation. When stably or transiently overexpressed, ATF3 markedly accelerated the drug‐induced apoptosis and enhanced caspase protease activation. ATF3 strongly downregulated CRE‐dependent transcription, while ATF3 did not affect the expression levels of Bcl‐2, Bcl‐x, or Bax. Our present results indicate that ATF3 plays a critical role in accelerating caspase protease activation and apoptosis. Since CRE‐dependent transcription functions as cell survival signaling, ATF3 could control the upstream signaling of apoptosis by repressing CRE‐dependent gene expression of cell survival factors. © 2001 Wiley‐Liss, Inc.
Effect of the aeration rate on pullulan production and fermentation broth rheological properties in an airlift reactor
Authors: Roukas T , Mantzouridou F
Published: August 2002

The effect of aeration rate on pullulan production and the rheological properties of the fermentation broth in an airlift reactor was investigated. An airlift fermenter was shown to be an appropriate fermentation system for the production of pullulan. A maximum pullulan concentration (30 kg m−3), biomass concentration (6.0 kg m−3), pullulan yield (60%, w/w) and sugar utilization (100%, w/w) was obtained at an aeration rate of 2 vvm. The mycelium and the yeast‐like cells were the morphological forms responsible for pullulan production. The highest polysaccharide concentration was obtained when the mycelial forms and the yeast‐like cells were 60% and 40% (w/w) of the total biomass, respectively. The apparent viscosity of the broth was increased with the increase of the aeration rate from 1 to 2 vvm and then decreased at higher vvms. On the other hand, the dissolved oxygen concentration and the volumetric mass transfer coefficient continually increased with the increase of the aeration rate. The mycelial forms and the production of extracellular polysaccharide were responsible for the non‐Newtonian flow behaviour of the fermentation broth. The rheological behaviour can be characterized by a power law type of equation. The relationship between shear rate/shear stress and shear rate/apparent viscosity showed a non‐Newtonian behaviour of the fermentation broth.

© 2001 Society of Chemical Industry
Color Doppler sonography of hepatic artery reconstruction in liver transplantation
Authors: De Candia Alessandro , Como Giuseppe , Tedeschi Luigi , Zanardi Romeo , Vergendo Maurizio , Rositani Pasquale , Bazzocchi Massimo
Published: August 2002

Purpose

The purpose of this study was to evaluate the Doppler spectral waveforms in the hepatic artery after liver transplantation and hepatic artery reconstruction by end‐to‐end anastomosis or aortohepatic bypass. The peak systolic velocities (PSVs), end‐diastolic velocities (EDVs), and resistance indices (RIs) between the 2 reconstruction groups were compared to establish normal post‐transplantation values.

Methods

We retrospectively reviewed the Doppler sonograms and the sonographic reports from 48 patients who had undergone liver transplantation, 30 with end‐to‐end arterial anastomoses and 18 with aortohepatic bypasses. All aortohepatic bypasses had been performed using the infrarenal technique. All sonographic examinations had been performed 3–6 months after transplantation in patients with no clinical sign of transplant failure and whose liver function test results more normal. We compared the mean hepatic artery PSVs, EDVs, and RIs of the 2 groups.

Results

Doppler spectral analysis allowed the detection of 2 types of arterial flow, a low‐resistance pattern in the end‐to‐end anastomosis group and a high‐resistance pattern with low diastolic flow in the infrarenal bypass group. The mean PSV ± standard deviation (SD) was 57 ± 16 seconds in the end‐to‐end anastomosis group and 62 ± 16 cm/second in the infrarenal bypass group. The mean EDV ± SD was 25 ± 14 cm/second in the end‐to‐end anastomosis group and 12 ± 4 cm/second in the infrarenal bypass group. The RIs ranged from 0.33 to 0.71 (mean ± SD, 0.58 ± 0.13) in the patients with end‐to‐end anastomoses and from 0.70 to 0.87 (mean ± SD, 0.77 ± 0.06) in those with infrarenal bypasses. The difference in the mean RIs between the 2 groups was statistically significant (p < 0.05).

Conclusions

Spectral waveform and RI are associated with the length and caliber of the type of hepatic artery anastomosis used. End‐to‐end anastomoses are short and have a uniform small caliber; aortohepatic bypasses are longer and have a progressively by smaller caliber. We must be cognizant of the method of anastomosis used when examining patients for complications after liver transplantation because the method used affects the resulting spectral waveform and RI. © 2002 John Wiley & Sons, Inc. J Clin Ultrasound 30:12–17, 2002.
Single molecule studies by means of the two‐photon fluorescence distribution
Authors: Chirico Giuseppe , Cannone Fabio , Beretta Sabrina , Baldini Giancarlo , Diaspro Alberto
Published: August 2002

We have characterized a commercial confocal scanning head for the detection of single molecule fluorescence by two‐photon excitation. We have verified that the distribution of the fluorescence emitted by dyes and labeled proteins on glass substrates is discrete with quanta proportional to a common reference signal. We describe and test a simple and quantitative tool to discriminate between single molecules and molecular aggregates on single snapshots based on the analysis of the intensity distribution. We have verified the square dependence of the fluorescence intensity vs. the excitation power, suggesting that no appreciable saturation and fast photo‐damage of the chromophores takes place at the excitation power employed here. Microsc. Res. Tech. 55:359–364, 2001. © 2001 Wiley‐Liss, Inc.
Magnocellular vasopressin system in ontogenesis: Development and regulation
Authors: Ugrumov Michael V.
Published: August 2002

This review is devoted to the development, functional activity, and regulation of the magnocellular vasopressin (VP) system in ontogenesis. Magnocellular VP neurons originate in embryos from the neuroepithelium of the third ventricle and migrate first to the supraoptic nucleus and then to the paraventricular nucleus and accessory nuclei. The preproVP gene and synthesis are expressed simultaneously in the newly formed neurons either during migration or just after arrival in magnocellular nuclei. Still, a number of VP‐immunoreactive neurons increase in immature mammals to prepuberty, which is explained by VP expression in the initially “silent” neurons, or by an increase of VP synthesis that makes a cell distinguishable by immunocytochemistry. An enzymatic processing of preproVP is slightly delayed compared to the onset of preproVP synthesis. Axons of magnocellular neurons reach the pituitary posterior lobe before or just after the neuron arrival in magnocellular nuclei. The mechanisms of VP release from the axon terminals are developed in immature animals over the perinatal period. The VP neurons begin to react to functional (osmotic) stimulation by increased synthesis of VP mRNA and VP in immature animals from the end of fetal life. A functional maturation of the VP system is under control by neural afferents, neuropeptides, and some hormones of endocrine glands. Namely, glucocorticoids, VP, catecholamines, glutamate, and opioids provide short‐term or long‐lasting effects on differentiating VP neurons. Most of the intercellular signals inhibit the specific phenotype expression of differentiating VP neurons: VP gene and synthesis in normal conditions, as well as TH gene and synthesis under functional stimulation. Microsc. Res. Tech. 56:164–171, 2002. © 2002 Wiley‐Liss, Inc.
FMRFamide in the amphibian brain: A comprehensive survey
Authors: Rastogi Rakesh K. , D'Aniello Biagio , Pinelli Claudia , Fiorentino Maria , Di Fiore Maria M. , Di Meglio Maria , Iela Luisa
Published: August 2002

Mapping of FMRFamidergic neural circuitry in the amphibian brain has been done by immunohistochemical methods. Comparative evidence suggests that there are similarities and differences in the overall pattern of distribution of FMRFamide‐ir elements in the brain among the three amphibian orders and within each order. FMRFamide is expressed in neurons in some circumscribed areas of the brain. A part of these neurons is concentrated in classical neurosecretory areas of the hypothalamus in a bilaterally symmetrical fashion. Similar neurons occur occasionally in the midbrain, but are virtually absent from the hindbrain. Anurans are unique among amphibians to show FMRFamide neurons in the medial septum and diagonal band of Broca. A viviparous gymnophione is known to possess a small population of such neurons in the dorsal thalamus. Together, the FMRFamide neurons contribute to an extensive fiber network throughout the amphibian brain. Descriptive developmental studies suggest that the rostral forebrain‐located FMRFamide neurons originate in the olfactory placode and then migrate into the brain along the route of the vomeronasal‐olfactory‐terminal nerve complex. Olfactory placodal ablation in an anuran and a urodele provide experimental support to this contention. Other FMRFamide neuronal cell groups, in the hypothalamus and dorsal thalamus, are supposed to arise from non‐placodal precursors. The neuroanatomical distribution (projection of immunoreactive processes to areas of the fore‐, mid‐, and hindbrain as well as to cerebrospinal fluid, co‐localization with other neuropeptides, and presence in the median eminence) has furnished morphological correlates of possible functions of FMRFamide in the amphibian CNS. While amphibian FMRFamide‐like or structurally related peptides remain to be isolated and characterized, the sum of the distribution pattern of FMRFamide‐like immunoreactivity suggests that it may act as a neurotransmitter or a neuromodulator, and also may have endocrine regulatory functions. Microsc. Res. Tech. 54:158–172, 2001. © 2001 Wiley‐Liss, Inc.
Distribution patterns and morphology of sensilla on the apical segment of the antennae and palpi of Hydradephaga (Coleoptera: adephaga)
Authors: Baker Gerald T.
Published: August 2002

The sensilla on the terminal antennomere of selected Hydradephagans (Coleoptera) are modified in several distinct ways as compared to the sensilla on the terminal antennomere of Geadephagans (Coleoptera). There are no long sensilla of any type on antennae of Hydradephagans, the sensilla are either short, peg‐like sensilla that may be recessed in the antennal surface or they are multiporous plate‐like sensilla. Multiporous plate‐like sensilla have not been found on the antennae of Geadephagans. A pit sensillum occurs on the antennae of one family, Gyrinidae, in the Hydradephaga whereas it is found on the antennae of several species from the families of Geadephaga. The sensilla on the terminal antennomere of Hydradephaga are often grouped into sensory fields that could be located on a particular area of the antennomere. Sensory fields are also located on the apices of the maxillary and labial palps and the most unique sensory fields occur in the Noteridae. The maxillary palpal apex of Hydrocanthus oblongus (Noteridae) is bifurcate and a sensory field with several types of sensilla is at the apex of each branch. The terminal labial palpomere is greatly enlarged and has a long, slender sensory field at the apex and a secondary sensory field on a thumb‐like projection. The sensilla on the palpal apices are more diverse and complex in form as compared to the sensilla on the palps of Geadephaga. The most complex sensillum has a cuticular collar and a dome that is divided into six or seven triangular sections. The dome maybe opened or closed and a peg‐like sensillum with a very wide apical pore is situated beneath the dome. Microsc. Res. Tech. 55:330–338, 2001. © 2001 Wiley‐Liss, Inc.
Ped gene deletion polymorphism frequency in wild mice
Authors: Newmark Judith A. , Sacher Frank , Jones Gwilym S. , Warner Carol M.
Published: August 2002

The Ped gene influences the rate of cleavage of preimplantation embryos and their subsequent survival. Embryos that express the product of the Ped gene, Qa‐2 protein, cleave at a faster rate than embryos with an absence of Qa‐2 protein. In addition, the Ped gene has pleiotropic effects on reproduction. Thus, there is a reproductive advantage to those mouse strains that are Qa‐2 positive. The presence or absence of Qa‐2 is reflected at the DNA level by the presence or absence (deletion polymorphism) of the gene(s) encoding Qa‐2 protein. Many inbred and wild‐derived mouse strains have been characterized as Qa‐2 positive or negative, but no previous studies have looked at the distribution of the Ped gene in a population of free‐living wild mice. The purpose of this study was to determine the Ped gene deletion polymorphism frequency in a sample of free‐living wild mice. Twenty‐nine mice were collected and identified as Mus musculus. Genomic DNA extraction was performed on tail tips, and PCR was used to amplify a region from the Ped gene. Known Qa‐2 positive and negative mice were used as controls. Results showed that all 29 wild mice were positive for the Ped gene. Since the Ped gene is dominant and provides a reproductive advantage, it is not surprising that all of the wild mice were Qa‐2 positive. However, our assay could not distinguish homozygous from heterozygous mice. It is possible that the Qa‐2 deletion polymorphism is segregating in the population, and a larger sample size would identify some Qa‐2 negative mice. © 2002 Wiley‐Liss, Inc.
Phenotype plasticity in postural muscles of the crayfish Orconectes limosus Raf.: Correlation of myofibrillar ATPase‐based fiber typing with electrophysiological fiber properties and the effect of chronic nerve stimulation
Authors: Gruhn Matthias , Rathmayer Werner
Published: August 2002

The characteristics of the medial and lateral superficial extensor muscles (sem and sel) in the crayfish Orconectes limosus abdomen and their developmental and activity‐dependent plasticity were studied. It was shown that both muscles are innervated by at least five excitatory and one inhibitory motor neuron in a nonuniform pattern. The muscles are composed of at least three different mATPase histochemistry‐based fiber types that are all different from a fourth type in the uniform deep extensor muscles. sem and sel are composed of different ratios of these fiber types but do not show a constant fiber type pattern between segments and even between hemisegments. The three histochemically defined superficial extensor‐fiber types have characteristic electrophysiological properties. The fiber types were shown to develop successively during the first postembryonic stages of development without a change in the number of muscle fibers. Based on histochemical ATPase staining after 21 days of chronic stimulation by means of an implantable, double‐hook electrode, we show preliminary evidence that the fiber composition in the sem can switch from the presumably fast fiber type III to an intermediate type II. Repeated axotomy up to 53 days had no effect on the fiber type composition of the muscles. © 2002 Wiley‐Liss, Inc.
Phylogenetic distribution of apolipoproteins A‐I and E in vertebrates as determined by Western blot analysis
Authors: Duggan Annemarie E. , Callard Ian P.
Published: August 2002

A putative apolipoprotein E (apoE) has been identified in the HDL and VHDL fractions of the turtle. This observation is of particular interest considering apoE has been reported absent in the domestic hen (Hermier et al., ’95; Biochim Biophys Acta: 105–118, 1995) and thus presumed absent in nonmammalian vertebrates altogether. As a result, partial amino acid sequencing of this protein was performed and revealed that one fragment shared 41% sequence identity to human apoE. Western blot analysis using antisera to apoE demonstrated cross‐reactivity to a 34‐kDa protein (putative apoE) in turtle plasma. Further investigation using anti‐apoE antibody in Western blot analysis detected immunoreactive apoE in the plasma of lamprey, spiny dogfish, skate, and alligator, but not in flounder, newt or python; its absence in several species of birds was confirmed. Using anti‐apoA‐I antibody, apoA‐I was detected in all vertebrate groups except a representative teleost (flounder). Apo‐A‐I antibody cross‐reacted weakly with some putative apoE proteins (chicken, spiny dogfish and skate) and the reverse was true for anti‐apoE, which cross‐reacted with putative apoA‐I in birds, reptiles, and elasmobranchs, confirming the molecular similarity and phylogenetic relatedness of these two proteins. J. Exp. Zool. 290:255–264, 2001. © 2001 Wiley‐Liss, Inc.
Highly efficient gene transfer into antigen‐specific primary mouse lymphocytes with replication‐deficient retrovirus expressing the 10A1 envelope protein
Authors: Annenkov Alexander E. , Daly Gordon M. , Chernajovsky Yuti
Published: August 2002

Background

Introduction of recombinant genes in the genome of primary lymphocytes by virtue of a replication‐deficient retrovirus can be used in immunological studies and for cell‐based gene therapy.

Methods

Packaging cells GP+E86 producing replication‐deficient retrovirus incorporating the genes of enhanced green fluorescent protein (eGFP), C2γ or C2ξ, were generated by calcium phosphate‐mediated transfection. Clones with the highest titres of retrovirus vector were isolated from them and their supernatants were used for transduction of PT67 cells. Primary mouse lymphocytes and T‐cell hybridoma MD.45 were transduced by centrifugation with retroviral stock. The retroviral content of packaging cell supernatants was determined by dot blotting and hybridization with a DNA probe.

Results

PT67 cells produced ∼50 times more retrovirus vector than the original GP+E86 clones. When retroviral stocks of PT67 and GP+E86 cells were used at 1/50 dilution and undiluted, respectively (to normalize them forretroviral RNA content), the transduction efficiency of mouse T‐cell hybridoma was 40% and 5%, respectively. Centrifugation of target cells with retroviral stock at 2000 g for 60 min increased the percentage of transduced cells two‐ to three‐fold. Within a population of cells isolated from the draining lymph nodes of an immunized mouse and reactivated with an antigen, up to 60% of CD4+ T cells and up to 80% of B cells could be transduced with a transgene in replication‐deficient retrovirus packaged by PT67 cells using the optimized gene transfer protocol.

Conclusions

This protocol allows for the generation of packaging cells producing high titres of retrovirus vector. The 10A1 envelope protein is superior to the ecotropic one for the transduction of mouse lymphocytes. Copyright © 2002 John Wiley & Sons, Ltd.
Packing trees into planar graphs
Authors: García A. , Hernando C. , Hurtado F. , Noy M. , Tejel J.
Published: August 2002

In this study, we provide methods for drawing a tree with n vertices on a convex polygon, without crossings and using the minimum number of edges of the polygon. We apply the results to obtain planar packings of two trees in some specific cases. © 2002 Wiley Periodicals, Inc. J Graph Theory 40: 172–181, 2002
Hamiltonian cycles in n‐extendable graphs
Authors: Kawarabayashi Ken‐ichi , Ota Katsuhiro , Saito Akira
Published: August 2002

A graph G of order at least 2n+2 is said to be n‐extendable if G has a perfect matching and every set of n independent edges extends to a perfect matching in G. We prove that every pair of nonadjacent vertices x and y in a connected n‐extendable graph of order p satisfy degG x+degG y ≥ p − n − 1, then either G is hamiltonian or G is isomorphic to one of two exceptional graphs. © 2002 Wiley Periodicals, Inc. J Graph Theory 40: 75–82, 2002
Policy analysis matrices: beyond simple sensitivity analysis
Authors: Morrison Jamie , Balcombe Kelvin
Published: August 2002

As an analytical methodology, the Policy Analysis Matrix (PAM) can be used to provide indicators of the incentives faced by producers in a given policy and institutional environment. However, the methodology suffers from the limitation that the analyst is unable to attach any level of confidence to the results, other than that generated through sensitivity analysis. In this paper the technique of bootstrapping is introduced as a general method for assessing the degree of uncertainty surrounding indicators derived from PAMs. The example of wheat production in Slovakia is used to demonstrate the usefulness of the additional information generated by this approach. Copyright © 2002 John Wiley & Sons, Ltd.
Testing for the law of one price: rice market integration in Bangladesh
Authors: Dawson P. J. , Dey P. K.
Published: August 2002

Recent studies of spatial market integration have adopted error correction models to test for its existence and for market dominance. An integrated empirical framework is proposed here which tests for long‐run spatial market integration between price pairs using a dynamic vector autoregressive model and cointegration. Hypotheses tests of market integration, perfect market integration, and causality are conducted sequentially. The approach is illustrated using monthly prices from rice markets in Bangladesh since trade liberalisation in 1992. Results show that rice markets are perfectly integrated and that Dhaka dominates near markets but is dominated by more distant markets. Copyright © 2002 John Wiley & Sons, Ltd.