bluuebunny/crossref_metadata_2025_split huggingface dataset:
Surgical technique for totally implantable access ports (TIAP) needs improvement: A multivariate analysis of 400 patients
Authors: Seiler Christoph M. , Frohlich Boris E. , Dorsam Ulrich J. , Kienle Peter , Buchler Markus W. , Knaebel Hanns‐Peter 
Published: December 2005

AbstractBackgroundThe objective of this study was to analyze factors that may have an impact on the failure rate of the surgical implantation technique for totally implantable access ports (TIAP) and to assess whether morbidity rates differ between a primarily successful surgical and a secondary Seldinger approach.MethodsFour hundred consecutive patients receiving a primary TIAP in local anesthesia were included into this retrospective cohort study. A logistic regression‐model was used to evaluate reasons for failure of the TIAP method.ResultsThree hundred eighteen (79.5%) patients had a successful TIAP procedure, 82 patients were intraoperatively converted to a Seldinger technique. Reasons for failure were: correct positioning impossible n = 54, no or only an undersized vessel for insertion available n = 17, other reasons n = 11. Logistic regression analysis did not reveal any significant factor for failure of the primary surgical approach. In the group with primarily successful TIAP, 8 of 318 patients (3%) developed complications compared to 7 of 82 patients (9%) converted to a Seldinger technique.ConclusionFailure of the surgical approach for implanting totally implantable access ports is related to insertion and positioning. Conversion to a Seldinger technique results in a higher complication rate. A modified approach for surgical port placement should be considered in order to reduce complications. J. Surg. Oncol. 2006;93:24–29. © 2005 Wiley‐Liss, Inc.
The epidermal growth factor receptor gene sequence is highly conserved in primary gastric cancers
Authors: Mimori Koshi , Nagahara Hisashi , Sudo Tomoya , Ishii Hideshi , Yamashita Keishi , Barnard Graham F. , Mori Masaki 
Published: December 2005

AbstractBackground and ObjectivesRecent studies have disclosed the presence of somatic mutations in the epidermal growth factor receptor (EGFR) gene in non‐small cell lung cancers (NSCLC), and susceptibility to the EGFR tyrosine kinase inhibitor (gefitinib) was determined by the presence of mutations in the kinase domain of this gene. We thus predicted a clinical benefit of gefitinib against the 12% of primary colorectal cancers exhibiting a mutation reflective of this potential distinctive susceptibility.Patients and MethodsThe mutation status of the kinase domain in EGFR in different primary cancers has important clinical consequences, because the presence of a mutation is recognized as a reliable indicator for the effectiveness of gefitinib administration. In the current study, we investigated the presence of somatic mutations in exons 18–21 coding the ATP‐binding domain in five gastric cancer cell lines and 39 primary gastric cancers and their corresponding normal tissues.Results and ConclusionsThe kinase domain of EGFR is highly conserved in whole gastric cancer cell lines and cases, therefore treatment with gefitinib is unfortunately not recommended for such malignancy. J. Surg. Oncol. 2006;93:44–46. © 2005 Wiley‐Liss, Inc.
Immunoglobulin VH genes in thymic MALT lymphoma are biased toward a restricted repertoire and are frequently unmutated
Authors: Yoshida Megumi , Okabe Mitsukuni , Eimoto Tadaaki , Shimizu Shinichiro , Ueda‐Otsuka Kayo , Okamoto Masataka , Ishii Genichiro , Ueda Ryuzo , Chan John K C , Nakamura Shigeo , Inagaki Hiroshi 
Published: December 2005

AbstractThymic MALT lymphoma shows certain distinctive features among MALT lymphomas, such as expression of IgA isotype, consistent lack of API2–MALT1 gene fusion, and very strong association with autoimmune disease, especially Sjogren's syndrome. To help clarify the nature of the clonal lymphoid infiltrates, we analysed the usage and somatic hypermutation of the Ig heavy chain variable region (VH) genes in nine different cases. The VH rearrangement was potentially functional in all cases and was restricted to the VH3 family. VH usage was biased toward VH3‐30 (five cases) and VH3‐23 (three cases) segments, which have both been frequently expressed by autoimmune B cells. Somatic hypermutation was absent in five cases. Fewer than the expected replacement mutations were found in the framework regions in two cases, indicating a negative antigen selection pressure. Ongoing mutation was absent in all cases. D segment usage was varied, whereas JH segment usage was restricted to JH4. The observed patterns of VH usage and mutations suggested that specific antigens may play a pathologically relevant role in the genesis or progression of thymic MALT lymphoma. Copyright © 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Cytokine gene expression profile distinguishes CD4+/CD57+ T cells of the nodular lymphocyte predominance type of Hodgkin's lymphoma from their tonsillar counterparts
Authors: Atayar Çiǧdem , Poppema Sibrand , Visser Lydia , van den Berg Anke 
Published: December 2005

AbstractLittle is known about the cytokine profile of nodular lymphocyte predominance Hodgkin's lymphoma (NLPHL) and the significance of the characteristic rosetting CD4+/CD57+ T cells. We analysed the T lymphocyte populations isolated from lymph node suspensions from five patients with NLPHL, two with follicular hyperplasia and progressive transformation of germinal centres (PTGC), three with classical Hodgkin's lymphoma (CHL) and five with hyperplasia of the tonsil. We sorted the T cells based on expression of CD3, CD4 and CD57 by flow cytometry and evaluated the cytokine mRNA profiles of the T cells with quantitative RT‐PCR. NLPHL cases were as rich in T cells as the CHL cases, but all NLPHL cases had a much higher frequency of CD4+/CD57+ T cells. In contrast to the CD4+/CD57+ T cells from tonsils, IL2 and IL4 mRNAs were consistently absent from the CD4+/CD57+ T cells of NLPHL. Even after stimulation, no IL4 transcripts could be detected in the CD4+/CD57+ T cells of NLPHL. On the other hand, IFNγ transcripts were elevated in NLPHL and PTGC T cell subsets as compared to tonsillar T cell subsets. IL13 mRNA was exclusively produced by the T cells of CHL cases, indicating that IL13 may be a key cytokine in CHL. In conclusion, elevated levels of CD4+/CD57+ T cells are characteristic of NLPHL and these T cells display a distinct cytokine mRNA profile. Copyright © 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Knock‐down of hepatitis B virus X protein reduces the tumorigenicity of hepatocellular carcinoma cells
Authors: Chan David Wai , Oi‐lin Ng Irene 
Published: December 2005

AbstractHepatitis B virus (HBV) infection is a major cause of hepatocellular carcinoma (HCC) in Southeast Asia and Hong Kong. Among the four proteins that are encoded by the HBV genome, HBV X (HBx) is the most potentially oncogenic factor. It is known that HBx plays an important role in hepatocarcinogenesis, but the exact functions and molecular mechanisms of HBx in HCC are not well understood. In this study, we constructed expression vectors for small hairpin RNAs (shRNA) against HBx and investigated their regulatory effects in PLC/PRF/5 HCC cells, which constitutively produce HBx. Our data show that this tool of RNA interference (RNAi) could successfully reduce the HBx mRNA and protein levels by 50–95%. RNAi targeting HBx in PLC/PRF/5 cells demonstrated significant reduction in cell proliferation, cell growth, anchorage‐independent growth in soft agar, and tumour development in nude mice. In addition, depletion of HBx expression increased cell sensitivity to TNFα‐mediated and serum‐free‐induced apoptosis, and reduced the expression levels of C‐myc and Bcl‐XL. These findings suggest that HBx plays an important role in tumorigenicity and anti‐apoptotic mechanisms in HCC. Copyright © 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Lack of genetic and epigenetic changes in meningiomas without NF2 loss
Authors: van Tilborg Angela AG , Morolli Bruno , Giphart‐Gassler Micheline , de Vries Annie , van Geenen Daniëlle AN , Lurkin Irene , Kros Johan M , Zwarthoff Ellen C 
Published: December 2005

AbstractApproximately 60% of sporadic meningiomas are caused by inactivation of the NF2 tumour suppressor gene. The causative gene for the remaining meningiomas is unknown. Previous studies have shown that these tumours have no recurrent karyotypic abnormalities. They differ from their NF2‐related counterparts in that they are more often of the meningothelial subtype and are located preferentially in the anterior skull base. To gain more insight into the aetiology of these tumours, we studied genetic and epigenetic alterations in 25 meningiomas without NF2 involvement. We first established a genome‐wide allelotype using 3 microsatellite markers per chromosome arm. Loss of heterozygosity (LOH) was detected at a low frequency and no indication for the location of putative tumour suppressor genes could be established. We next screened the subtelomeric regions by using 2–3 polymorphic markers close to each telomere. Again no evidence for LOH of a particular chromosome arm was obtained, and no LOH was found in the genomic regions containing the NF2‐related ERM family members ezrin and radixin, DAL‐1, protein 4.1R, and TSLC1. Mutations in the X‐chromosome based family member, moesin, were analysed by SSCP and were not detected. Microsatellite instability was studied using 6 commonly used markers but none of these was altered in any meningioma. Methylation was detected in 5 of 16 genes (NF2, p14ARF, CDH1, BRCA1, RB1) previously shown to be silenced in a variety of tumour types. However, methylation percentages for these genes were generally higher in a group of NF2‐related meningiomas, with the exception of the BRCA1 gene. The NF2 gene was methylated in only 1 of 21 tumours. In conclusion, meningiomas with an intact NF2 gene have a normal karyotype and no obvious genetic or epigenetic aberrations, suggesting that the gene(s) involved in the pathogenesis of these tumours are altered by smaller events than can be detected with the techniques used in our study. Copyright © 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Hydrogen bonding increases packing density in the protein interior
Authors: Schell David , Tsai Jerry , Scholtz J. Martin , Pace C. Nick 
Published: December 2005

AbstractThe contribution of hydrogen bonds and the burial of polar groups to protein stability is a controversial subject. Theoretical studies suggest that burying polar groups in the protein interior makes an unfavorable contribution to the stability, but experimental studies show that burying polar groups, especially those that are hydrogen bonded, contributes favorably to protein stability. Understanding the factors that are not properly accounted for by the theoretical models would improve the models so that they more accurately describe experimental results. It has been suggested that hydrogen bonds may contribute to protein stability, in part, by increasing packing density in the protein interior, and thereby increasing the contribution of van der Waals interactions to protein stability. To investigate the influence of hydrogen bonds on packing density, we analyzed 687 crystal structures and determined the volume of buried polar groups as a function of their extent of hydrogen bonding. Our findings show that peptide groups and polar side chains that form hydrogen bonds occupy a smaller volume than the same groups when they do not form hydrogen bonds. For example, peptide groups in which both polar groups are hydrogen bonded occupy a volume, on average, 5.2 Å3 less than a peptide group that is not hydrogen bonded. Proteins 2006. © 2005 Wiley‐Liss, Inc.
Quantitative determination of piritramide in human plasma and urine by off‐ and on‐line solid‐phase extraction liquid chromatography coupled to tandem mass spectrometry
Authors: Kahlich Rainer , Gleiter Christoph H. , Laufer Stefan , Kammerer Bernd 
Published: December 2005

AbstractA method for the liquid chromatography/tandem mass spectrometric (LC/MS/MS) quantification of piritramide, a synthetic opioid, in plasma after conventional off‐line solid‐phase extraction (SPE) and in urine by on‐line SPE‐LC/MS/MS in positive electrospray mode was developed and validated. Applicability of the on‐line approach for plasma samples was also tested. Deuterated piritramide served as internal standard. For the off‐line SPE plasma method mixed cation‐exchange SPE cartridges and a 150 × 2 mm C18 column with isocratic elution were used. For the on‐line SPE method, a Waters Oasis HLB extraction column and the same C18 analytical column in a column‐switching set‐up with gradient elution were utilized. All assays were linear within a range of 0.5–100 ng/mL with a limit of detection of 0.05 ng/mL. The intra‐ and interday coefficients of variance ranged from 1.3 to 6.1% for plasma and 0.5 to 6.4% for urine, respectively. The extraction recovery for the off‐line plasma assay was between 90.7 and 100.0%. Influence of matrix effects, and freeze/thaw and long‐term stability were validated for both approaches; influence of urine pH additionally for quantification in urine. Copyright © 2005 John Wiley & Sons, Ltd.
13C/12C isotope labelling to study leaf carbon respiration and allocation in twigs of field‐grown beech trees
Authors: Nogués Salvador , Damesin Claire , Tcherkez Guillaume , Maunoury Florence , Cornic Gabriel , Ghashghaie Jaleh 
Published: December 2005

AbstractIn situ 13C/12C isotopic labelling was conducted in field‐grown beech (Fagus sylvatica) twigs to study carbon respiration and allocation. This was achieved with a portable gas‐exchange open system coupled to an external chamber. This method allowed us to subject leafy twigs to CO2 with a constant carbon isotope composition (δ13C of −51.2‰) in an open system in the field. The labelling was done during the whole light period at two different dates (in June 2002 and October 2003). The δ13C values of respiratory metabolites and CO2 that is subsequently respired during the night were measured. It was found that night‐respired CO2 is not completely labelled (only ca. 58% and 27% of new carbon is found in respired CO2 immediately after the labelling in June 2002 and October 2003, respectively) and the labelling level progressively disappeared during the next day. It is concluded that the carbon respired by beech leaves after illumination was supplied by a mixture of carbon sources in which current carbohydrates were not the only contributors. In addition, as has been found in herbaceous plants, isotopic data before labelling showed that carbon isotope discrimination favoring the 13C isotope occurred during the night respiration of beech leaves. Copyright © 2005 John Wiley & Sons, Ltd.
Systematic identification of N‐acetylheparosan oligosaccharides by tandem mass spectrometric fragmentation
Authors: Minamisawa Toshikazu , Suzuki Kiyoshi , Hirabayashi Jun 
Published: December 2005

AbstractRecently, a useful procedure for the preparation of both even‐ and odd‐numbered series of N‐acetylheparosan (NAH) oligosaccharides was established. The present report describes findings when these NAH oligosaccharides were subjected to comparative mass spectrometry (MS)/MS fragmentation analysis by matrix‐assisted laser desorption/ionization (MALDI)‐LIFT‐time‐of‐flight (TOF)/TOF‐MS/MS, and electrospray ionization (ESI) collision‐induced dissociation (CID) MS/MS. The resultant fragment ions were systematically assigned to elucidate fragmentation characteristics. In the MALDI‐LIFT‐MS/MS experiments, all the NAH oligosaccharides underwent unique glycosidic cleavages that included B‐Y ion cleavages (nomenclature system of Domon and Costello, Glycoconjugate J. 1988; 5: 397) at the C‐1 side, and C‐Z ion cleavages at the C‐4 side, with respect to glucuronic acid (GlcA). In addition, 0,2A and/or 0,2X cross‐ring cleavages were observed for relatively small oligosaccharides. The former observation clearly reflects the occurrence of a GlcA‐N‐acetylglucosamine (GlcNAc) alternating structure of NAH, while the latter feature implies the occurrence of the ‐β‐1‐4‐glucuronide linkage. Extensive glycosidic cleavages were also observed in the ESI‐CID‐MS/MS fragmentation, though cleavage specificity was less evident than in the case of MALDI‐LIFT‐TOF/TOF‐MS/MS. The information obtained in this study should be valuable for understanding both biosynthetic and degradation processes of NAH and its derivatives including heparin and heparan sulfate, as well as artificially modified NAH oligosaccharides. Copyright © 2005 John Wiley & Sons, Ltd.
Investigation of disulfonamide ligands derived from o‐phenylenediamine and their Pb(II) complexes by electrospray ionization mass spectrometry
Authors: Zhang Weihua , Cai Yong , Kavallieratos Konstantinos 
Published: December 2005

AbstractAn electrospray ionization mass spectrometry (ESI‐MS) method, in both positive and negative ion modes, was developed for characterization of disulfonamide ligands derived from o‐phenylenediamine and their Pb(II) complexes. For the ligands, negative ion mode ESI‐MS in methanolic solutions gave simple and easily interpretable mass spectra. However, the spectra of Pb complexes were not readily interpretable under the same conditions. Protonated ligands and their Pb(II) complexes were observed in methanolic solutions by ESI‐MS in positive ion mode. The formation of Na+, K+, or NH adducts was also observed, complicating the mass spectra and decreasing the signal intensity. In order to optimize the detection of the ligands and the Pb complexes, a method was developed by adding NaOAc in the solutions. The presence of 0.2 mM NaOAc simplified the mass spectra of the ligands and the Pb complexes, and significantly increased sensitivity in both negative and positive ion modes. This modification makes ESI‐MS in both modes suitable for characterization of sulfonamide ligands and their Pb complexes, thus providing a potentially powerful tool for evaluating formation of metal complexes and screening combinatorial ligand libraries. Copyright © 2005 John Wiley & Sons, Ltd.
Multilevel logistic regression modelling with correlated random effects: application to the Smoking Cessation for Youth study
Authors: Wang Kui , Lee Andy H. , Hamilton Greg , Yau Kelvin K. W. 
Published: December 2005

AbstractA multilevel logistic regression model is presented for the analysis of clustered and repeated binary response data. At the subject level, serial dependence is expected between repeated measures recorded on the same individual. At the cluster level, correlations of observations within the same subgroup are present due to the inherent hierarchical setting. Two random components are therefore incorporated explicitly within the linear predictor to account for the simultaneous heterogeneity and autoregressive structure. Application to analyse a set of longitudinal data from an adolescent smoking cessation intervention that motivated this study is illustrated. Copyright © 2005 John Wiley & Sons, Ltd.
Robust estimation in mixed linear models with non‐monotone missingness
Authors: Yun Sungcheol , Lee Youngjo 
Published: December 2005

AbstractWe introduce a model to account for abrupt changes among repeated measures with non‐monotone missingness. Development of likelihood inferences for such models is hard because it involves intractable integration to obtain the marginal likelihood. We use hierarchical likelihood to overcome such difficulty. Abrupt changes among repeated measures can be well described by introducing random effects in the dispersion. A simulation study shows that the resulting estimator is efficient, robust against misspecification of fatness of tails. For illustration we use a schizophrenic behaviour data presented by Rubin and Wu. Copyright © 2005 John Wiley & Sons, Ltd.
Poor response to 18‐month lamivudine monotherapy in chronic hepatitis B patients with IgM anti‐HBc and acute exacerbation
Authors: CHEN J‐J. , LIN C‐Y. , SHEU M‐J. , KUO H‐T. , SUN C‐S. , TANG L‐Y. , WANG S‐L. , TSAI S‐L. 
Published: December 2005

SummaryBackgroundAppearance of immunoglobulin class M antibody against hepatitis B core antigen is a predictor of beneficial response to interferon‐alpha therapy in chronic hepatitis B patients, but its relationship with the efficacy of lamivudine therapy remains unclear.AimTo investigate the outcome of lamivudine therapy in chronic hepatitis B patients with immunoglobulin class M antibody against hepatitis B core antigen and acute exacerbation.MethodsChronic hepatitis B patients with acute exacerbation receiving a national‐wide therapeutic trial of 18‐month lamivudine monotherapy were enrolled for the analysis. Four consecutive seronegative patients were recruited as individual matching controls of one positive subject. Immunoglobulin class M antibody against hepatitis B core antigen in serum was assayed monthly by an automated microparticle enzyme immunoassay.ResultsFifteen (8.9%) of 167 chronic hepatitis B patients with acute exacerbation were seropositive for IgM anti‐HBc. Thus 60 seronegative patients were consecutively recruited as control group. At the end of therapy, two (13.3%) of the 15 seropositive patients achieved a sustained response, significantly lower than 26 (43.3%) of the control group.ConclusionsAppearance of immunoglobulin class M antibody against hepatitis B core antigen in chronic hepatitis B patients with acute exacerbation is a predictor of poor response to lamivudine monotherapy. This is clinically relevant to the decision‐making in treating chronic hepatitis B patients with acute exacerbation.
5‐aminosalicylic acid release from a new controlled‐release mesalazine formulation during gastrointestinal transit in healthy volunteers
Authors: BRUNNER M. , LACKNER E. , EXLER P. S. , DE FLUITER H. C. , KLETTER K. , TSCHURLOVITS M. , DUDCZAK R. , EICHLER H.‐G. , MÜLLER M. 
Published: December 2005

SummaryBackgroundMesalazine (5‐aminosalicylic acid, 5‐ASA) containing formulations represent a cornerstone in the treatment of inflammatory bowel diseases. A novel formulation with an Eudragit L/S mixture coating has been developed to provide selective release of 5‐ASA to the ileo‐caecal region and the colon.AimTo determine the release of 5‐ASA during the gastrointestinal transit.MethodsA single oral dose of mesalazine EC 500 mg gastroresistant tablets (Asamax) was administered to eight healthy male volunteers. Gastrointestinal transit and tablet disintegration were monitored by scintigraphy. 5‐ASA release was verified by assessing plasma pharmacokinetics.ResultsInitial tablet disintegration was observed 5.65 ± 0.86 h after dosing, corresponding to the detection of 5‐ASA in plasma. This occurred in the ileo‐caecal region in three subjects and the ascending colon in the remaining five. The relative percentage of 5‐ASA absorption was more pronounced in the ascending colon (41 ± 27.4%) than the ileo‐caecal region (6.6 ± 9.2%).ConclusionThis mesalazine EC gastroresistant tablets release locally active 5‐ASA specifically in the ileo‐caecal region and the ascending colon.