bluuebunny/crossref_metadata_2025_split huggingface dataset:
Human model of duodenogastro–oesophageal reflux in the development of Barrett's metaplasia (Br J Surg 2003; 90: 1120-1128)
Authors: Barham C P , Alderson D 
Published: November 2003

Abstract
The Editors welcome topical correspondence from readers relating to articles published in the Journal. Responses can be sent electronically via the BJS website (www.bjs.co.uk) or by post. All letters will be reviewed and, if approved, appear on the website. A selection of these will be edited and published in the Journal. Letters must be no more than 250 words in length. Letters submitted by post should be typed on A4-sized paper in double spacing and should be accompanied by a disk.
A comparative reappraisal of projections from the superficial laminae of the dorsal horn in the rat: The forebrain
Authors: Gauriau Caroline , Bernard Jean‐François 
Published: November 2003

AbstractProjections to the forebrain from lamina I of spinal and trigeminal dorsal horn were labeled anterogradely with Phaseolus vulgaris‐leucoagglutinin (PHA‐L) and/or tetramethylrhodamine‐dextran (RHO‐D) injected microiontophoretically. Injections restricted to superficial laminae (I/II) of dorsal horn were used primarily. For comparison, injections were also made in deep cervical laminae. Spinal and trigeminal lamina I neurons project extensively to restricted portions of the ventral posterolateral and posteromedial (VPL/VPM), and the posterior group (Po) thalamic nuclei. Lamina I also projects to the triangular posterior (PoT) and the ventral posterior parvicellular (VPPC) thalamic nuclei but only very slightly to the extrathalamic forebrain. Furthermore, the lateral spinal (LS) nucleus, and to a lesser extent lamina I, project to the mediodorsal thalamic nucleus. In contrast to lamina I, deep spinal laminae project primarily to the central lateral thalamic nucleus (CL) and only weakly to the remaining thalamus, except for a medium projection to the PoT. Furthermore, the deep laminae project substantially to the globus pallidus and the substantia innominata and more weakly to the amygdala and the hypothalamus. Double‐labeling experiments reveal that spinal and trigeminal lamina I project densely to distinct and restricted portions of VPL/VPM, Po, and VPPC thalamic nuclei, whereas projections to the PoT appeared to be convergent. In conclusion, these experiments indicate very different patterns of projection for lamina I versus deep laminae (III–X). Lamina I projects strongly onto relay thalamic nuclei and thus would have a primary role in sensory discriminative aspects of pain. The deep laminae project densely to the CL and more diffusely to other forebrain targets, suggesting roles in motor and alertness components of pain. J. Comp. Neurol. 468:24–56, 2004. © 2003 Wiley‐Liss, Inc.
Differences in the expression of AMPA and NMDA receptors between axospinous perforated and nonperforated synapses are related to the configuration and size of postsynaptic densities
Authors: Ganeshina Olga , Berry Robert W. , Petralia Ronald S. , Nicholson Daniel A. , Geinisman Yuri 
Published: November 2003

AbstractAxospinous synapses are traditionally divided according to postsynaptic density (PSD) configuration into a perforated subtype characterized by a complex‐shaped PSD and nonperforated subtype exhibiting a simple‐shaped, disc‐like PSD. It has been hypothesized that perforated synapses are especially important for synaptic plasticity because they have a higher efficacy of impulse transmission. The aim of the present study was to test this hypothesis. The number of postsynaptic AMPA receptors (AMPARs) is widely regarded as the major determinant of synaptic efficacy. Therefore, the expression of AMPARs was evaluated in the two synaptic subtypes and compared with that of NMDA receptors (NMDARs). Postembedding immunogold electron microscopy was used to quantify the immunoreactivity following single labeling of AMPARs or NMDARs in serial sections through the CA1 stratum radiatum of adult rats. The results showed that all perforated synapses examined were immunopositive for AMPARs. In contrast, only a proportion of nonperforated synapses (64% on average) contained immunogold particles for AMPARs. The number of immunogold particles for AMPARs was markedly and significantly higher in perforated synapses than in immunopositive nonperforated synapses. Although all synapses of both subtypes were NMDAR immunopositive perforated synapses contained significantly more immunogold particles for NMDARs than nonperforated ones. Multivariate analysis of variance revealed that the mode of AMPAR and NMDAR expression is related to the complexity of PSD configuration, not only to PSD size. These findings support the notion that perforated synapses may evoke larger postsynaptic responses relative to nonperforated synapses and, hence, contribute to an enhancement of synaptic transmission associated with some forms of synaptic plasticity. J. Comp. Neurol. 468:86–95, 2004. Published 2003 Wiley‐Liss, Inc.
Profile of the climate change in the Kingdom of Bahrain
Authors: Alnaser W. E. , Merzaa M. K. 
Published: November 2003

AbstractLong‐term meteorological data from the Kingdom of Bahrain (1902 to 2001), along with other data from the Sultanate of Oman and the Kingdom of Saudi Arabia, were used to study the profile and the characteristics of the climate changes in the Kingdom of Bahrain. This article illustrates the possible effects of several factors, such as greenhouse gases (GHG), sunspot number, cosmic ray flux, planet conjunctions, the Earth's magnetic field, as well as volcanic eruption, on the profile of the climate change. In general, we found that the temperature variations, to a certain extent, are associated with the cyclic variations in sunspot number (the 11‐year cycle), which in turn affect the pattern of the cosmic ray flux due to the distortion of the interplanetary magnetic field. The latter is believed to influence cloud formation. In addition, the discrepancy in the climate change pattern in Bahrain was also attributed to the combined effect of the high local level of CO2 emissions as well as that of other cooling gases in the region. Copyright © 2003 John Wiley & Sons, Ltd.
Synergistic interaction between the EGFR tyrosine kinase inhibitor gefitinib (“Iressa”) and the DNA topoisomerase I inhibitor CPT‐11 (irinotecan) in human colorectal cancer cells
Authors: Koizumi Fumiaki , Kanzawa Fumihiko , Ueda Yutaka , Koh Yasuhiro , Tsukiyama Shoji , Taguchi Fumiko , Tamura Tomohide , Saijo Nagahiro , Nishio Kazuto 
Published: November 2003

AbstractEpidermal growth factor receptor [EGFR (HER1, erbB1)] is a receptor with associated tyrosine kinase activity, and is expressed in colorectal cancers and many other solid tumors. We examined the effect of the selective EGFR tyrosine kinase inhibitor (EGFR‐TKI) gefitinib (“Iressa”) in combination with the DNA topoisomerase I inhibitor CPT‐11 (irinotecan) on human colorectal cancer cells. EGFR mRNA and protein expression were detected by RT‐PCR and immunoblotting in all 7 colorectal cancer cell lines studied. Gefitinib inhibited the cell growth of the cancer cell lines in vitro with an IC50 range of 1.2–160 μM by 3,(4,5‐dimethyl‐2‐thiazolyl)‐2,5‐diphenyl‐2H‐tetrazolium bromide (MTT) assay. Lovo cells exhibited the highest level of protein and autophosphorylation of EGFR and were the most sensitive to gefitinib. The combination of gefitinib and CPT‐11 induced supra‐additive inhibitory effects in COLO320DM, WiDR and Lovo cells, assessed by an in vitro MTT assay. Administration of gefitinib and CPT‐11 had a supra‐additive inhibitory effect on WiDR cells and tumor shrinkage was observed in Lovo cell xenografts established in nude mice, whereas no additive effect of combination therapy was observed in COLO320DM cells. To elucidate the mechanisms of synergistic effects, the effect of CPT‐11‐exposure on phosphorylation of EGFR was examined by immunoprecipitation. CPT‐11 increased phosphorylation of EGFR in Lovo and WiDR cells in time‐ and dose‐dependent manners. This EGFR activation was completely inhibited by 5 μM gefitinib and gefitinib‐induced apoptosis was enhanced by combination with CPT‐11, measured by PARP activation although no PARP activation was induced by 5 μM CPT‐11 alone. These results suggested that these modification of EGFR by CPT‐11, in Lovo cells, is a possible mechanism for the synergistic effect of CPT‐11 and gefitinib. These findings imply that the EGFR‐TKI gefitinib and CPT‐11 will be effective against colorectal tumor cells that express high levels of EGFR, and support clinical evaluation of gefitinib in combination with CPT‐11, in the treatment of colorectal cancers. © 2003 Wiley‐Liss, Inc.
Contribution of MEK/MAPK and PI3‐K signaling pathway to the malignant behavior of Ewing's sarcoma cells: Therapeutic prospects
Authors: Benini Stefania , Manara Maria Cristina , Cerisano Vanessa , Perdichizzi Stefania , Strammiello Rosaria , Serra Massimo , Picci Piero , Scotlandi Katia 
Published: November 2003

AbstractInsulin‐like growth factor receptor I (IGF‐I)‐mediated circuit is a major autocrine loop for Ewing's sarcoma (ES) cells and appears to be particularly important in the pathogenesis of this tumor. In this study, we analyzed the contribution of the 2 major pathways of the intracellular IGF‐IR signaling cascade to the overall effects elicited by IGF‐I in ES. Both the mitogen‐activated protein kinase (MAPK) and phosphatidylinositol‐3‐kinase (PI3‐K) signaling pathways appeared to be constitutively activated in ES, likely due to the presence of the IGF‐IR‐mediated autocrine loop. We demonstrated that both MEK/MAPK (PD98059 or U0126) and PI3‐K inhibitors (LY294002) profoundly impaired ES cell growth in monolayer and soft agar basal conditions. Both PD98059 and LY294002 inhibited ES cell cycle progression by inducing G1 blockage, whereas only LY294002 significantly affected the survival of ES cells. Exogenous IGF‐I completely reverted LY294002‐induced growth inhibition by abrogating antiproliferative and proapoptotic effects of the PI3‐K inhibitor. By contrast, IGF‐I could not rescue cells from growth inhibition induced by PD98059. MEK/MAPK blockade also significantly reduced the migratory ability of ES cells, both in basal and IGF‐I‐induced conditions, and increased chemosensitivity to doxorubicin, a leader drug in the treatment of ES patients. Our findings therefore identify MAPK pathway as a promising target for pharmacologic intervention in ES. © 2003 Wiley‐Liss, Inc.
Prediction and classification of protein subcellular location—sequence‐order effect and pseudo amino acid composition
Authors: Chou Kuo‐Chen , Cai Yu‐Dong 
Published: November 2003

AbstractGiven a protein sequence, how to identify its subcellular location? With the rapid increase in newly found protein sequences entering into databanks, the problem has become more and more important because the function of a protein is closely correlated with its localization. To practically deal with the challenge, a dataset has been established that allows the identification performed among the following 14 subcellular locations: (1) cell wall, (2) centriole, (3) chloroplast, (4) cytoplasm, (5) cytoskeleton, (6) endoplasmic reticulum, (7) extracellular, (8) Golgi apparatus, (9) lysosome, (10) mitochondria, (11) nucleus, (12) peroxisome, (13) plasma membrane, and (14) vacuole. Compared with the datasets constructed by the previous investigators, the current one represents the largest in the scope of localizations covered, and hence many proteins which were totally out of picture in the previous treatments, can now be investigated. Meanwhile, to enhance the potential and flexibility in taking into account the sequence‐order effect, the series‐mode pseudo‐amino‐acid‐composition has been introduced as a representation for a protein. High success rates are obtained by the re‐substitution test, jackknife test, and independent dataset test, respectively. It is anticipated that the current automated method can be developed to a high throughput tool for practical usage in both basic research and pharmaceutical industry. © 2003 Wiley‐Liss, Inc.
Direct dynamic study on the hydrogen abstraction reaction CH3CN + OH → CH2CN + H2O
Authors: Li Qian‐Shu , Wang Chao Yang 
Published: November 2003

AbstractThe reaction of acetonitrile with hydroxyl has been studied using the direct ab initio dynamics methods. The geometries, vibrational frequencies of the stationary points, as well as the minimum energy paths were computed at the BHandHLYP and MP2 levels of theory with the 6‐311G(d, p) basis set. The energies were further refined at the PMP4/6‐311+G(2df, 2pd) and QCISD(T)/6‐311+G(2df, 2pd) levels of theory based on the structures optimized at BHandHLYP/6‐311G(d, p) and MP2/6‐311G(d, p) levels of theory. The Polyrate 8.2 program was employed to predict the thermal rate constants using the canonical variational transition state theory incorporating a small‐curvature tunneling correction. The computed rate constants are in good agreement with the available experimental data. © 2003 Wiley Periodicals, Inc. J Comput Chem 25: 251–257, 2004
Conformation‐dependent intermolecular interaction energies of the triphosphate anion with divalent metal cations. Application to the ATP‐binding site of a binuclear bacterial enzyme. A parallel quantum chemical and polarizable molecular mechanics investigation
Authors: Gresh Nohad , Shi Gen‐Bin 
Published: November 2003

AbstractWe have explored the conformation‐dependent interaction energy of the triphosphate moiety, a key constituent of ATP and GTP, with a closed‐shell divalent cation, Zn2+, used as a probe. This was done using the SIBFA polarizable molecular mechanics procedure. We have resorted to a previously developed approach in which triphosphate is built out from its elementary constitutive fragments, and the intramolecular, interfragment, interaction energies are computed simultaneously with their intermolecular interactions with the divalent cation. This approach has enabled reproduction of the values of the intermolecular interaction energies from ab initio quantum‐chemistry with relative errors <3%. It was extended to the complex of a nonhydrolyzable analog of ATP with the active site of a bacterial enzyme having two Mg2+ cations as cofactors. We obtained following energy‐minimization a very close overlap of the ATP analog over its position from X‐ray crystallography. For models of the ATP analog–enzyme complex encompassing up to 169 atoms, the values of the SIBFA interaction energies were found to match their DFT counterparts with relative errors of <2%. © 2003 Wiley Periodicals, Inc. J Comput Chem 25: 160–168, 2004
Computational study of conformational preferences of thioamide‐containing azaglycine peptides
Authors: Lee Ho‐Jin , Kim Jong Hyun , Jung Hee Jung , Kim Kun‐Young , Kim Eun‐Jung , Choi Young‐Sang , Yoon Chang‐Ju 
Published: November 2003

AbstractThe effect of thioamide substitution on the conformational stability of an azaglycine‐containing peptide, For‐AzaGly‐NH2 (1), was investigated for the sake of finding possible applications by using ab initio and DFT methods. As model compounds, For‐[ΨCSNH]‐AzaGly‐NH2 (2), For‐AzaGly‐[ΨCSNH]‐NH2 (3), and For‐[ΨCSNH]‐AzaGly‐[ΨCSNH]‐NH2 (4) were used. Two‐dimensional ϕ‐ψ potential energy surfaces (PESs) for 2–4 were calculated at the B3LYP/6‐31G*//HF/6‐31G* level in gas (ε = 1.0) and in water (ε = 78.4) by applying the isodensity polarizable continuum model (IPCM) method. On the basis of these PESs, the minimum energy conformations for 2–4 were characterized at the B3LYP level with 6‐31G*, 6‐311G**, and 6‐31+G** basis sets. The remarkable structural effect of thioamide substitution for 2–4 is that β‐strand structure is observed as a global or local minimum. The minima of 2–4 are also compared with those for glycine and thioamide‐containing glycine peptides. Our theoretical results demonstrate that compounds 2–4 would be used to design controllable secondary structures. © 2003 Wiley Periodicals, Inc. J Comput Chem 25: 169–178, 2004
Detection of low copy numbers of HIV‐1 proviral DNA in patient PBMCs by a high‐input, sequence‐capture PCR (Mega‐PCR)
Authors: Böni Jürg , Shah Cyril , Flepp Markus , Lüthy Ruedi , Schüpbach Jörg 
Published: November 2003

AbstractAn internally controlled high‐input PCR method, termed HIV‐1 Mega‐PCR was developed to lower the detection limit of HIV‐1 DNA polymerase chain reaction (PCR) and to improve its value as a complementary diagnostic test. It is based on PCR amplification of two target sequences in the gag gene of HIV‐1 following the selective capture of the targeted sequence and removal of unselected DNA from up to 500 μg of DNA. Efficient selection and amplification was monitored by inclusion of two mimic plasmids. The method was evaluated with buffy coat cells from healthy blood donors which were spiked with blood from 106 different HIV‐1‐infected individuals, and with 107 HIV‐1 seronegative control buffy coats. All specimens from HIV‐infected individuals were positive by a PCR protocol using 1 μg of patient DNA. Amplification of 1 μg DNA of the 106 spiked, diluted samples resulted in 68 double positive, 14 single positive, and 24 double negative reactions. In the Mega‐PCR, the average input was 260 ± 84 μg DNA containing an estimated 1.1 ± 0.6% of spiked patient DNA. Of the 106 samples tested by Mega‐PCR, 102 were positive and three negative. One failed to select the mimic plasmid. Among the 107 negative buffy coat controls, none was false‐positive and four exhibited a failure of the internal reaction control. Application of HIV‐1 Mega‐PCR to clinical specimens from seroreverting newborns of HIV‐infected mothers and seroindeterminate, PCR‐negative specimens revealed no indication for HIV infection, whereas three samples from confirmed, HIV‐1‐infected but PCR negative individuals showed evidence of the presence of HIV‐1 DNA. Mega‐PCR lowers the detection limit of an individual analysis to approximately 0.01 HIV‐1 DNA copies/μg of applied DNA and may help to confirm or exclude HIV‐1‐infection in difficult situations diagnostic. J. Med. Virol. 72:1–9, 2004. © 2004 Wiley‐Liss, Inc.
Genetic variability of human rotavirus strains isolated from Eastern and Northern India
Authors: Das Soma , Varghese Vici , Chaudhuri Susmita , Barman Provaboti , Kojima Kazunobu , Dutta Phalguni , Bhattacharya Sujit K. , Krishnan Triveni , Kobayashi Nobumichi , Naik Trailokya N. 
Published: November 2003

AbstractAn epidemiological study was conducted in Eastern and Northern India to determine the genomic diversity of rotaviruses in these parts of the country. In 2001, a total of 126 Group A rotavirus positive samples were detected from children below 4 years of age with diarrhoea from Kolkata, Dibrugarh and Bhubaneswar in Eastern India, and Chandigarh, a city in Northern India. All the samples were genotyped for VP7 (G‐type) and VP4 (P‐type) gene by reverse transcription (RT) and multiplex PCR using different type specific primers. The strains with G1P[8] (32.5%) was predominant as reported earlier [Das et al. (2002) J Clin Microbiol 40:146–149] followed by G2P[4](4.7%) and only one sample was of G4P[8] specificity. Along with these common types some rare strains like G1P[6], G2P[8], G2P[6], G4P[4], and G4P[6] were also detected in 14.3% of cases. Thirty percent of samples in this study were mixed infections and 21 (16.7%) specimens remained untypeable either for the VP7 or for the VP4 gene. After sequencing of the VP7 gene, two G9 strains (RMC321 and ISO‐3) were identified with P[8] and P[19] specificities. Sequence analysis revealed that they have much lower homology to the G9 strains (116E, INL1, and G16) isolated earlier from Indian subcontinent, but have much higher homology to isolates from Argentina, Brazil, Malawi, Taiwan, and USA suggesting a separate progenitor for these strains. J. Med. Virol. 72:156–161, 2004. © 2004 Wiley‐Liss, Inc.
Hepatitis B viremia is associated with increased risk of hepatocellular carcinoma in chronic carriers
Authors: Tang Baiqing , Kruger Warren D. , Chen Gang , Shen Fumin , Lin Wen Yao , Mboup Souleymane , London W. Thomas , Evans Alison A. 
Published: November 2003

AbstractThe role of quantitative viral load in development of hepatocellular carcinoma (HCC) among chronic hepatitis B virus (HBV) carriers was evaluated using real‐time PCR (TaqMan PCR), a highly sensitive method for quantitative detection of HBV DNA. Serum samples collected at study entry from HCC cases and matched controls were chosen separately from ongoing prospective cohort studies in Senegal, West Africa, and Haimen City, China. For 14 HCC cases and 28 controls from Senegal, the relative risk (RR, 95% CI) of HCC was 15.6 (2.0–124.3) for those positive by the TaqMan PCR assay. Average length of follow‐up (study entry to death from HCC) among cases was 2.8 (±1.6) years. The paired median difference between cases and controls was 3.8 × 104 virions/ml, with cases higher (P = 0.09). In order to clarify the relationship with lower‐titer viremia, we selected 55 cases and 55 matched controls from the Chinese cohort all negative for serum HBV DNA by conventional dot blot hybridization. In this group, the RR associated with HBV DNA positivity by TaqMan PCR was 3.1 (1.1–9.2), with an average duration of follow‐up of 3.3 (±2.1) years. The median difference in quantitative viremia between cases and controls was 6.0×104 virions/ml, with cases higher (P < 0.0001). Increased risk appeared to be confined to subjects with viral loads >2.3 × 104 virions/ml. In conclusion, HBV viremia, except perhaps at extremely low levels, is associated with increased risk for HCC in prospective studies of chronic carriers in two disparate populations. J. Med. Virol. 72:35–40, 2004. © 2004 Wiley‐Liss, Inc.
Suppression of generation and replication of acyclovir‐resistant herpes simplex virus by a sensitive virus
Authors: Okuda Tomoko , Kurokawa Masahiko , Matsuo Koma , Honda Mariko , Niimura Michihito , Shiraki Kimiyasu 
Published: November 2003

AbstractThe role of acyclovir‐sensitive herpes simplex virus (HSV) was analyzed in the process of its replacement by a resistant virus in vitro and in vivo in the aspect of acyclovir therapy. The mode of replacement of acyclovir‐sensitive HSV with acyclovir‐resistant HSV was examined by the passages of acyclovir‐sensitive wild type HSV in Vero cells under acyclovir‐treatment. The development of resistance was monitored more adequately by counting the number of acyclovir‐resistant viruses in 10,000 plaque forming units than by the conventional susceptibility assay. The resistance increased with the proportion of thymidine kinase‐deficient (TK−) viruses, when the susceptibilities of acyclovir‐treated HSV population to 5′‐iodo‐2′deoxyuridine and phosphonoacetic acid were examined. The increased resistance was due to the increased proportion of acyclovir‐resistant virus but not intermediately resistant virus. Infection with mixtures of TK− and acyclovir‐sensitive strains rendered TK− sensitive to acyclovir, and virus yields were reduced to the levels of acyclovir‐sensitive virus in Vero cells. Their yield reduction depended on the proportion of acyclovir‐sensitive viruses and induction of TK activity. This reduction in virus yields of the mixture of TK− and acyclovir‐sensitive strains was confirmed by acyclovir treatment in the skin of mice with cutaneous infection. Acyclovir treatment combined with superinfection of acyclovir‐sensitive virus delayed the development of herpetic skin lesions due to acyclovir‐resistant virus and reduced virus yields in the infected skin. Acyclovir‐sensitive virus plays an important role in suppressing the generation and replication of acyclovir‐resistant virus during acyclovir therapy. J. Med. Virol. 72:112–120, 2004. © 2004 Wiley‐Liss, Inc.