bluuebunny/crossref_metadata_2025 huggingface dataset:
Roles of CXC chemokines and macrophages in the recruitment of inflammatory cells and tumor rejection induced by Fas/Apo‐1 (CD95) ligand‐expressing tumor
Authors: Shimizu Motomu , Yoshimoto Takayuki , Sato Mayumi , Morimoto Junji , Matsuzawa Akio , Takeda Yasutaka
Published: January 2005

The role of CD95 ligand (FasL/Apo‐1L)‐expressing tumors in immunosuppression or immunopotentiation is controversial. CD95L‐transfected tumors induce immunopotentiation after vigorous neutrophil infiltration. Thus, the induction of neutrophil infiltration by CD95L seems to play an important role in tumor rejection. The mechanism by which CD95L‐expressing tumors cause neutrophil infiltration and antitumor immunity has not been well understood. CXC chemokine receptor 2 (CXCR2) knockout (KO) mice are a powerful tool for studying CXC chemokine‐mediated neutrophil infiltration. We investigated the roles of CD95L and chemokines in CD95L‐induced antitumor activity by using CXCR2 KO mice and CD95LcDNA‐transfected MethA (MethA + CD95L) fibrosarcoma. MethA + CD95L cells were completely rejected in wild‐type (WT) and even in KO mice. MethA + CD95L cells injected intraperitoneally (i.p.) induced the recruitment of both neutrophils and macrophages in WT but only macrophages in KO mice, although CXC and CC chemokines were released in both mice. Macrophages incubated with MethA + CD95L cells released CXC and CC chemokines. Macrophages derived from WT and KO but not neutrophils from WT mice induced the recruitment of neutrophils when adoptively i.p. transferred with MethA + CD95L cells into CD95L/CD95‐deficient mice. The different recruitment of inflammatory cells between WT and KO mice was attributed to bone marrow (BM) cells by BM transfer experiment. Our results demonstrated that CXC chemokines are essential for neutrophil recruitment and that macrophages but not neutrophils play a critical role in the CD95L‐induced infiltration of inflammatory cells and the eradication of CD95L‐expressing tumor cells. © 2004 Wiley‐Liss, Inc.
Selective induction of apoptosis through the FADD/caspase‐8 pathway by a p53 c‐terminal peptide in human pre‐malignant and malignant cells
Authors: Li Yin , Mao Yuehua , Rosal Ramon V. , Dinnen Richard D. , Williams Ann C. , Brandt‐Rauf Paul W. , Fine Robert L.
Published: January 2005

A p53 C‐terminal peptide (aa 361–382, p53p), fused at its C‐terminus to the minimal carrier peptide of antennapedia (17 aa, Ant; p53p‐Ant), induced rapid apoptosis in human cancer cells, via activation of the Fas pathway. We examined p53p‐Ant mechanism of action, toxicity in various human normal, non‐malignant, pre‐malignant and malignant cancer cells and investigated its biophysical characteristics. p53p‐Ant selectively induced cell death in only pre‐malignant or malignant cells in a p53‐dependent manner and was not toxic to normal and non‐malignant cells. p53p‐Ant was more toxic to the mutant p53 than wild‐type p53 phenotype in H1299 lung cancer cells stably expressing human temperature‐sensitive p53 mutant 143Ala. Surface plasmon resonance (BIACORE) analysis demonstrated that this peptide had higher binding affinity to mutant p53 as compared to wild‐type p53. p53p‐Ant induced‐cell death had the classical morphological characteristics of apoptosis and had no features of necrosis. The mechanism of cell death by p53p‐Ant was through the FADD/caspase‐8‐dependent pathway without the involvement of the TRAIL pathway, Bcl‐2 family and cell cycle changes. Blocking Fas with antibody did not alter the peptide's effect, suggesting that Fas itself did not interact with the peptide. Transfection with a dominant‐negative FADD with a deleted N‐terminus inhibited p53p‐Ant‐induced apoptosis. Its mechanism of action is related to the FADD‐induced pathway without restoration of other p53 functions. p53p‐Ant is a novel anticancer agent with unique selectivity for human cancer cells and could be useful as a prototype for the development of new anti‐cancer agents. © 2004 Wiley‐Liss, Inc.
Predicting CIN2+ when detecting HPV mRNA and DNA by PreTect HPV‐proofer and consensus PCR: A 2‐year follow‐up of women with ASCUS or LSIL pap smear
Authors: Molden Tor , Nygård Jan F. , Kraus Irene , Karlsen Frank , Nygård Mari , Skare Gry Baadstrand , Skomedal Hanne , Thoresen Steinar Ø. , Hagmar Bjørn
Published: January 2005

It has been suggested that human papillomavirus (HPV) testing improves follow‐up of atypical cells of undetermined significance (ASCUS) and low‐grade squamous intraepithelial lesion (LSIL) in cervical cancer screening programs. To evaluate the prognostic value of including HPV testing as an adjunct to cytology, we carried out a 2‐year follow‐up study of 77 women with ASCUS or LSIL Papanicolaou (Pap) smear in the Norwegian Cervical Cancer Screening Program (NCCSP) for detection of histological cervical intraepithelial neoplasia (CIN) 2+. The study includes a comparison between viral mRNA and DNA detection. PreTect HPV‐Proofer was used for HPV E6/E7 mRNA detection from the 5 high‐risk types 16, 18, 31, 33 and 45, and Gp5+/6+ consensus PCR was used for HPV DNA detection. Twice as many women were positive for HPV DNA (54.6%) than for HPV mRNA (23.4%). PreTect HPV‐Proofer and consensus PCR had a sensitivity of 85.7% (95% confidence interval [CI] = 42.1–99.6) for detecting CIN2+ during follow‐up. The specificity was significantly higher for PreTect HPV‐Proofer, 84.9% (95% CI = 73.9–92.5), than for consensus PCR, 50.0% (95% CI = 37.4–62.6). PreTect HPV‐Proofer positive women were 69.8 times (95% CI = 4.3–1137.3) more likely to be diagnosed with CIN2+ within 2 years than PreTect HPV‐Proofer negative women. Consensus PCR‐positive women were 5.7 times (95% CI = 0.6–52.0) more likely to be diagnosed with CIN2+ within 2 years than PCR‐negative women. With equal sensitivity and higher specificity than consensus PCR, the PreTect HPV‐Proofer might offer an improvement for the triage of women with ASCUS or LSIL Pap smear. © 2004 Wiley‐Liss, Inc.
Development and validation of a liquid chromatographic/tandem mass spectrometric assay for the quantitation of nucleoside HIV reverse transcriptase inhibitors in biological matrices
Authors: Compain Séverine , Schlemmer Dimitri , Levi Mikaël , Pruvost Alain , Goujard Cécile , Grassi Jacques , Benech Henri
Published: January 2005

Besides liquid chromatographic (LC)/UV methods adapted to therapeutic drug monitoring, there is still a need for more powerful techniques that can be used for pharmacological research and clinical purposes. We developed an LC method coupled with tandem mass spectrometry (MS/MS) to separate, detect and quantify with high sensitivity the nucleoside analogues used in multitherapies (zidovudine, stavudine, zalcitabine, didanosine, lamivudine and abacavir) in plasma and in the intracellular medium. We worked on two essential issues: (i) the need to use two ionization modes in order to achieve the best sensitivity, which leads to the optimization of the chromatographic separation of drugs detected in the positive ionization mode and drugs detected in the negative ionization mode, and (ii) the need to optimize the extraction step in order to enhance sample recovery. The peripheral blood mononuclear cells were lysed in Tris buffer–MeOH. A clean‐up procedure was performed by solid‐phase extraction only for plasma samples. The LC separation was carried out on a Zorbax Stable Bond C18 column followed by MS/MS analysis after electrospray ionization in either the negative or positive mode. The positive ionization mode was applied at the beginning of the run to detect zalcitabine and lamivudine, then the ionization mode was changed to negative for the detection of didanosine, stavudine, internal standard and zidovudine. The calibration range for all the analytes was 0.5–200 ng ml−1. The recoveries were between 64 and 90%, with coefficients of variation (CVs) lower than 15%. The inaccuracy (bias) was ±15% with CVs always lower than 12%. The analytes were stable at room temperature and in the extraction solvent for at least 24 h, after storage at −80 °C for 3 months, after three freeze–thaw cycles and in the injection solvent after 48 h at 4 °C. Together with the measurement of intracellular triphosphorylated metabolites thanks to the powerful plasma and intracellular assay method for intact drugs, it is possible to describe the behaviour of nucleoside analogues against HIV through plasma pharmacokinetics, cell membrane diffusion including drug transport involvement, and also the intracellular metabolism. Copyright © 2005 John Wiley & Sons, Ltd.
Glycan side chains on naturally presented MHC class II ligands
Authors: Dengjel Jörn , Rammensee Hans‐Georg , Stevanovic Stefan
Published: January 2005

The molecular characterization of unknown naturally presented major histocompatibility complex (MHC) class II glycopeptides carrying complex glycans has so far not been achieved, reflecting the different fragmentation characteristics of sugars and peptides in mass spectrometric analysis. Human leukocyte antigen (HLA)‐DR‐bound peptides were isolated by affinity purification, separated via high performance liquid chromatography and analyzed by matrix‐assisted laser desorption/ionization and electrospray ionization mass spectrometry. We were able to identify two naturally processed MHC class II ligands, CD53122–136 and CD53121–136, carrying complex N‐linked glycan side chains by a combination of in‐source and collision‐induced fragmentation on a quadrupole time‐of‐flight tandem mass spectrometer. Copyright © 2005 John Wiley & Sons, Ltd.
New designer drug, 2,5‐dimethoxy‐4‐propylthio‐β‐phenethylamine (2C‐T‐7): studies on its metabolism and toxicological detection in rat urine using gas chromatography/mass spectrometry
Authors: Theobald Denis S. , Fehn Susanna , Maurer Hans H.
Published: January 2005

Studies are described on the metabolism and toxicological analysis of the phenethylamine‐derived designer drug 2,5‐dimethoxy‐4‐propylthio‐β‐phenethylamine (2C‐T‐7) in rat urine using gas chromatography/mass spectrometry (GC/MS). The identified metabolites indicated that 2C‐T‐7 was metabolized by hydroxylation of the propyl side chain followed by N‐acetylation and sulfoxidation and also by deamination followed by oxidation to the corresponding acid or by reduction to the corresponding alcohol. To a minor extent, 2C‐T‐7 was also metabolized by S‐dealkylation followed by N‐acetylation, S‐methylation and sulfoxidation. The authors' systematic toxicological analysis (STA) procedure using full‐scan GC/MS after acid hydrolysis, liquid–liquid extraction microwave‐assisted acetylation allowed the detection of an intake of a dose of 2C‐T‐7 in rat urine that corresponds to a common drug users' dose. Assuming similar metabolism, the described STA procedure should be suitable for proof of an intake of 2C‐T‐7 in human urine. Copyright © 2005 John Wiley & Sons, Ltd.
Influence of the laser pulse phase on the interaction of an
ultrashort laser pulse with a dense target
Authors: Blasco A J , Roso L , Plaja L
Published: January 2005

Using the recently obtained phase-controlled few-cycle
laser pulse profiles we numerically analyse the differences on the
dynamics of a strongly driven plasma. We study two-cycle carrier
amplitude envelopes with different electric field phases
interacting with a plasma slab, using a particle-in-cell code
1D3V. Results show the influence of the pulse phase on the
dynamics of the released electrons.
Subtraction of scattering parameters for small-signal modulation
characteristics of laser diode
Authors: Zhang S J , Zhu N H , Pun E Y B , Chung P S
Published: January 2005

An extended subtraction method of scattering parameters
for characterizing laser diode is proposed in this paper. The
intrinsic response is extracted from the measured transmission
coefficients of laser diode, and the parasitics of packaging
network and laser chip are determined from the measured reflection
coefficient of laser diode simultaneously. It is shown that the
theories agree well with the experimental results.
High power infrared laser beam monitoring by optical
measurement of mirror surface deformation
Authors: Ach F , Schmiedel A , Kaemling A , Fischer C , Viöl W
Published: January 2005

A new method for infrared laser beam diagnostics was
developed based on the interferometrical measurement of the
deflection mirror deformation. It is shown that with this method
the basic beam data as beam diameter, position, intensity and
within limits also intensity distribution can be determined with a
response time of less than 200 ms. The beam analysis method is
capable to monitor high power carbon dioxide laser beams in pulsed
and cw mode.
Short‐segment nerve conduction studies in the localization of ulnar neuropathy of the elbow: Use of flexor carpi ulnaris recordings
Authors: Lo Y. L. , Leoh T. H. , Xu L. Q. , Nurjannah S. , Dan Y. F.
Published: January 2005

Short‐segment nerve conduction studies were performed in 17 limbs with clinical features suggestive of ulnar neuropathy at the elbow. Recording from flexor carpi ulnaris yielded 93% sensitivity, compared with 71.4% when recording from abductor digiti minimi. The rationale underlying the technique is discussed. This approach should be of value as a diagnostic adjunct in technically challenging cases of ulnar neuropathy at the elbow. Muscle Nerve, 2005
Interfacial steady‐state and transient thermal fracture of dissimilar media using the boundary element contact analysis
Authors: Giannopoulos G. I. , Anifantis N. K.
Published: January 2005

A boundary element procedure is formulated to treat frictional contact problems of thermally stressed structures. The aim is the computation of steady‐state and time‐dependent thermal stress intensity factors of interfacial cracks in two‐dimensional bimaterial structures when crack closure conditions are present. The effect of friction between the crack faces is taken into consideration. The problems considered are formulated in an incremental and iterative fashion because of their non‐linear nature. Near crack tip singularities of temperature and displacement fields are modelled through appropriate quarter‐point singular elements. Fracture parameters are evaluated from nodal displacements of singular elements utilizing proper formulas. Numerical results are compared with available solutions from the literature, where possible. Good agreement between them can be found. Copyright © 2005 John Wiley & Sons, Ltd.
Mixed finite volume method for nonlinear elliptic problems
Authors: Kim Kwang Y.
Published: January 2005

In this article we construct and analyze a mixed finite volume method for second‐order nonlinear elliptic problems employing H(div; Ω)‐conforming approximations for the vector variable and completely discontinuous approximations for the scalar variable. The main attractive feature of our method is that, although the vector variable is H(div; Ω)‐conforming, one can eliminate it in a local manner to obtain a discontinuous Galerkin method for the scalar variable. Optimal error estimates will be established for both vector and scalar variables. We also present a fully discrete version of this method that is more convenient for computational purposes. © 2005 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2005
Morphology and thermal properties of poly(L‐lactide)/poly(butylene succinate‐co‐butylene adipate) compounded with twice functionalized clay
Authors: Chen Guang‐Xin , Yoon Jin‐San
Published: January 2005

Poly(L‐lactide) (PLLA)/poly(butylene succinate‐co‐butylene adipate) (PBSA) blends were compounded with Cloisite 25A® (C25A) and C25A functionalized with epoxy groups, respectively. Epoxy groups on the surface of C25A were introduced by treating C25A with (glycidoxypropyl)trimethoxy silane (GPS) to produce so called Twice Functionalized Organoclay (TFC). Variation of morphology and properties of PLLA/PBSA/C25A composites was investigated before and after the treatment with GPS. The morphological structure of the composites was analyzed by using X‐ray diffractometry (XRD) and transmission electron microscopy (TEM). The silicate layers of PLLA/PBSA/TFC were exfoliated to a larger extent than PLLA/PBSA/C25A. Incorporation of the epoxy groups on C25A improved significantly elongation at break as well as tensile modulus and tensile strength of PLLA/PBSA/C25A. The larger amount of exfoliation of the silicate layers in PLLA/PBSA/TFC as compared with that in PLLA/PBSA/C25A was attributed to the increased interfacial interaction between the polyesters and the clay due to chemical reaction. Thermo gravimetric analysis revealed that both T5%, which was the temperature corresponding to 5% weight loss, and activation energy of thermal decomposition of PLLA/PBSA/TFC were far superior to those of PLLA/PBSA/C25A as well as to those of PLLA/PBSA, indicating that the composites with exfoliated silicate layers were more thermally stable than those with intercalated silicate layers. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 478–487, 2005
Morphology of polyanhydride copolymers: Time‐resolved small‐angle X‐ray scattering studies of crystallization
Authors: Kipper Matt J. , Seifert Soenke , Thiyagarajan P. , Narasimhan Balaji
Published: January 2005

Synchrotron small‐angle X‐ray scattering (SAXS) was used to study the isothermal crystallization kinetics of a family of polyanhydride copolymers consisting of 1,6‐bis(p‐carboxyphenoxy)hexane and sebacic acid monomers. In situ SAXS experiments permitted the direct observation of the crystallization kinetics. The structural parameters (the long period, lamellar thickness, and degree of crystallinity) were obtained from Lorentz‐corrected intensity profiles, one‐dimensional correlation functions, and interface distribution functions to form a comprehensive picture of the crystal morphology. The combination of these three analyses provided information not only on the lamellar dimensions but also on the polydispersity (nonuniformity) of these dimensions. Where possible, the crystallization kinetics were interpreted with a modified version of the Avrami equation. The results can be used to perform the rational design of controlled‐drug‐release formulations because crystallinity affects drug‐release kinetics. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 463–477, 2005
Assigning new GO annotations to protein data bank sequences by combining structure and sequence homology
Authors: Ponomarenko Julia V. , Bourne Philip E. , Shindyalov Ilya N.
Published: January 2005

Accompanying the discovery of an increasing number of proteins, there is the need to provide functional annotation that is both highly accurate and consistent. The Gene Ontology™ (GO) provides consistent annotation in a computer readable and usable form; hence, GO annotation (GOA) has been assigned to a large number of protein sequences based on direct experimental evidence and through inference determined by sequence homology. Here we show that this annotation can be extended and corrected for cases where protein structures are available. Specifically, using the Combinatorial Extension (CE) algorithm for structure comparison, we extend the protein annotation currently provided by GOA at the European Bioinformatics Institute (EBI) to further describe the contents of the Protein Data Bank (PDB). Specific cases of biologically interesting annotations derived by this method are given. Given that the relationship between sequence, structure, and function is complicated, we explore the impact of this relationship on assigning GOA. The effect of superfolds (folds with many functions) is considered and, by comparison to the Structural Classification of Proteins (SCOP), the individual effects of family, superfamily, and fold. Proteins 2005. © 2005 Wiley‐Liss, Inc.
Crystal structure of the ferredoxin component of carbazole 1,9a‐dioxygenase of Pseudomonas resinovorans strain CA10, a novel Rieske non‐heme iron oxygenase system
Authors: Nam Jeong‐Won , Noguchi Haruko , Fujimoto Zui , Mizuno Hiroshi , Ashikawa Yuji , Abo Mitsuru , Fushinobu Shinya , Kobashi Nobuyuki , Wakagi Takayoshi , Iwata Kenichi , Yoshida Takako , Habe Hiroshi , Yamane Hisakazu , Omori Toshio , Nojiri Hideaki
Published: January 2005

The carbazole 1,9a‐dioxygenase (CARDO) system of Pseudomonas resinovorans strain CA10 catalyzes the dioxygenation of carbazole; the 9aC carbon bonds to a nitrogen atom and its adjacent 1C carbon as the initial reaction in the mineralization pathway. The CARDO system is composed of ferredoxin reductase (CarAd), ferredoxin (CarAc), and terminal oxygenase (CarAa). CarAc acts as a mediator in the electron transfer from CarAd to CarAa. To understand the structural basis of the protein–protein interactions during electron transport in the CARDO system, the crystal structure of CarAc was determined at 1.9 Å resolution by molecular replacement using the structure of BphF, the biphenyl 2,3‐dioxygenase ferredoxin from Burkholderia cepacia strain LB400 as a search model. CarAc is composed of three β‐sheets, and the structure can be divided into two domains, a cluster‐binding domain and a basal domain. The Rieske [2Fe–2S] cluster is located at the tip of the cluster‐binding domain, where it is exposed to solvent. While the overall folding of CarAc and BphF is strongly conserved, the properties of their surfaces are very different from each other. The structure of the cluster‐binding domain of CarAc is more compact and protruding than that of BphF, and the distribution of electric charge on its molecular surface is very different. Such differences are thought to explain why these ferredoxins can act as electron mediators in respective electron transport chains composed of different‐featured components. Proteins 2005. © 2005 Wiley‐Liss, Inc.
Prediction of protein B‐factor profiles
Authors: Yuan Zheng , Bailey Timothy L. , Teasdale Rohan D.
Published: January 2005

The polypeptide backbones and side chains of proteins are constantly moving due to thermal motion and the kinetic energy of the atoms. The B‐factors of protein crystal structures reflect the fluctuation of atoms about their average positions and provide important information about protein dynamics. Computational approaches to predict thermal motion are useful for analyzing the dynamic properties of proteins with unknown structures. In this article, we utilize a novel support vector regression (SVR) approach to predict the B‐factor distribution (B‐factor profile) of a protein from its sequence. We explore schemes for encoding sequences and various settings for the parameters used in SVR. Based on a large dataset of high‐resolution proteins, our method predicts the B‐factor distribution with a Pearson correlation coefficient (CC) of 0.53. In addition, our method predicts the B‐factor profile with a CC of at least 0.56 for more than half of the proteins. Our method also performs well for classifying residues (rigid vs. flexible). For almost all predicted B‐factor thresholds, prediction accuracies (percent of correctly predicted residues) are greater than 70%. These results exceed the best results of other sequence‐based prediction methods. Proteins 2005. © 2005 Wiley‐Liss, Inc.
Simulation of pesticide leaching in a cracking clay soil with the PEARL model
Authors: Scorza Júnior Rômulo P , Boesten Jos JTI
Published: January 2005

Testing of pesticide leaching models is important to increase confidence in their use in pesticide registration procedures world‐wide. The chromatographic PEARL model was tested against the results of a field leaching study on a cracking clay soil with a tracer (bromide), a mobile pesticide (bentazone) and a moderately sorbing, persistent pesticide (imidacloprid). Input parameters for water flow and solute transport were obtained from site‐specific measurements and from literature. The model was tested using a stepwise approach in which each sub‐model was sequentially and separately tested. Uncalibrated simulations for the water flow resulted in moisture profiles that were too wet. Calibration of the hydraulic relationships resulted in a good description of the moisture profiles. Calibration of the dispersion length was necessary to obtain a good description of bromide leaching. The calibrated dispersion length was 61 cm, which is very long and indicates a large non‐uniformity of solute transport. The half‐life of bentazone had to be calibrated to obtain a good description of its field persistence. The calibrated half‐life was 2.5 times shorter than the half‐life derived from the laboratory studies. Concentrations of bentazone in drain water and groundwater were described reasonably well by PEARL. Although measured and simulated persistence of imidacloprid in soil corresponded well, the bulk of the imidacloprid movement was overestimated by PEARL. However, imidacloprid concentrations in drain water were underestimated. In spite of the extensive calibration of water flow and tracer movement, the behaviour of the moderately sorbing pesticide imidacloprid could not be simulated. This indicates that the convection–dispersion equation cannot be used for accurate simulation of pesticide transport in cracking clay soils (even if extremely long dispersion length is used). Comparison of the model results from a poorly sorbed chemical (bentazone) and a moderately sorbed chemical (imidacloprid) were useful in defining the limitations of using a chromatographic flow model to simulate the effects of preferential flow. Copyright © 2005 Society of Chemical Industry
Development of a method for simultaneous determination of eflucimibe and its three major metabolites in rat plasma by liquid chromatography/electrospray tandem mass spectrometry: a preliminary study
Authors: Mesplet Nathalie , Morin Philippe , Ribet Jean‐Paul
Published: January 2005

A high‐performance liquid chromatography/electrospray ionisation tandem mass spectrometry (HPLC/ESI‐MS/MS) method has been developed for the simultaneous determination of eflucimibe, a powerful acyl‐coenzyme A cholesterol O‐acyltransferase (ACAT) inhibitor, and its main metabolites, in plasma. The ESI and MS/MS parameters were investigated and optimised for each of the four compounds in the positive ion mode. Plasma samples were deproteinised by precipitation with acetonitrile and directly analysed by HPLC/ESI‐MS/MS in less than 4 min. Quantitation was performed in the multiple reaction monitoring (MRM) mode for highest sensitivity, selecting the protonated molecules [M+H]+ as precursor ions. The method was demonstrated to be specific and sensitive, and a linear response was observed within a 1–25 ng/mL concentration range. Correlation coefficients (r2) greater than 0.9960 were obtained by least‐squares regression, and limits of detection down to 0.2 ng/mL were calculated. Therefore, this HPLC/ESI‐MS/MS method appears to be an efficient tool, able to provide valuable information for a pharmacological purpose. Copyright © 2005 John Wiley & Sons, Ltd.
Determination of lincomycin and tylosin residues in honey by liquid chromatography/tandem mass spectrometry
Authors: Thompson Thomas S. , Noot Donald K. , Calvert Jane , Pernal Stephen F.
Published: January 2005

A simple and rapid analytical method was developed for the determination of lincomycin and tylosin residues in honey as part of field studies examining the efficacy and target animal safety of these antibiotics to control American foulbrood disease in honey bees. Residues of the antibiotics were determined using liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI‐MS/MS). Honey samples were diluted and injected directly into the LC/MS/MS system without additional cleanup by solid‐phase extraction or liquid‐liquid partitioning. A six‐port valve system was utilized to selectively route eluant from the LC column into the mass spectrometer only during a relatively short portion of the chromatographic run corresponding to the elution of the analytes of interest. Minimal contamination of the MS source chamber was observed despite the analysis of large numbers of samples. Using internal standard quantitation, excellent accuracy and precision were obtained with no apparent matrix‐to‐matrix variation. Based on the analysis of fortified replicates, the mean percent deviation from the theoretical concentration and the percent relative standard deviation were both less than 10% for tylosin over an analytical range of 10–1000 μg/kg. Slightly higher mean percent deviations and relative standard deviations were observed for the analysis of lincomycin in fortified replicate samples. The method detection limits were determined to be 5 and 2 μg/kg for lincomycin and tylosin, respectively. Copyright © 2005 John Wiley & Sons, Ltd.
Hydropyrolysis as a preparative method for the compound‐specific carbon isotope analysis of fatty acids
Authors: Sephton Mark A. , Meredith Will , Sun Cheng‐Gong , Snape Colin E.
Published: January 2005

Compound‐specific stable carbon isotope analysis by gas chromatography/combustion/isotope ratio mass spectrometry is an effective and risk‐free means of investigating fatty acid metabolism. Straightforward analysis, however, leads to poor chromatographic resolution, while derivatization adds carbon thereby corrupting the starting stable isotopic composition. Hydropyrolysis is a new approach which defunctionalizes fatty acids to yield the corresponding n‐alkanes thus retaining the carbon skeleton intact and improving chromatography, allowing the faithful measurement of carbon isotope ratios. Copyright © 2005 John Wiley & Sons, Ltd.
Genome‐wide survey of non‐essential genes required for slowed DNA synthesis‐induced filamentous growth in yeast
Authors: Kang Christopher Minkyu , Jiang Yi Wei
Published: January 2005

We recently discovered that slowed DNA synthesis induces filamentous differentiation in S. cerevisiae. We screened the BY yeast deletion strains and identified four classes of non‐essential genes that are required for both slowed DNA‐induced filamentous growth and classic forms of filamentous growth: (a) genes encoding regulators of the actin cytoskeleton and cell polarity, ABP1, CAP2 and HUF1 (= YOR300W), in addition to the previously known BNI1, BUD2, PEA2, SPA2 and TPM1; (b) genes that are likely involved in cell wall biosynthesis, ECM25, GAS1 and PRS3; (c) genes encoding possible regulators of protein secretion, SEC66, RPL21A and RPL34B; (d) genes encoding factors for normal mitochondrial function, IML1 and UGO1. These results showed that pseudohyphal formation involves not the only previously known regulation of the actin cytoskeleton/cell polarity but also regulation of cell wall synthesis, protein secretion and mitochondrial function. Identification of multiple classes of genes that are required for both slowed DNA synthesis‐induced and classic forms of filamentous growth confirms that slowed DNA synthesis‐induced filamentous growth is bone fide filamentous differentiation. Copyright © 2005 John Wiley & Sons, Ltd.
Involvement of actin and polarisome in morphological change during spore germination of Saccharomyces cerevisiae
Authors: Kono Keiko , Matsunaga Rino , Hirata Aiko , Suzuki Genjiro , Abe Mitsuhiro , Ohya Yoshikazu
Published: January 2005

We studied the morphological changes of Saccharomyces cerevisiae ascospores during germination. Initiation of germination is followed by polarization of actin patches, maintaining their localization to the site of cell surface growth. Loss of polarisome components, Spa2p, Pea2p, Bud6p or Bni1p, results in depolarization of actin patches. Green fluorescent protein‐fused polarisome components exhibit the polarized localization, implying that polarisome is involved in the polarized outgrowth during germination. At the late stage of germination, we found that actin patches temporally depolarize before bud emergence. The observation that loss of Cla4p extends the polarized growth period suggests that Cla4p is involved in the actin‐depolization step. Actin polarization in the initial stage is accelerated by overexpression of Ras2p, whereas hyperpolarization is continuously observed by overexpression of Rho1p. Thus, yeast spore germination is a morphological event that is regulated by a number of factors implicated in mitotic bud morphogenesis. Copyright © 2005 John Wiley & Sons, Ltd.
SKG1, a suppressor gene of synthetic lethality of kex2Δgas1Δ mutations, encodes a novel membrane protein that affects cell wall composition
Authors: Tomishige Nario , Noda Yoichi , Adachi Hiroyuki , Shimoi Hitoshi , Yoda Koji
Published: January 2005

The fungal GAS1‐related genes encode GPI‐anchored β‐1,3‐glucanosyltransferase, and their loss causes a defect in the assembly of the cell wall. The KEX2 gene encodes a processing protease in the late Golgi compartment and its loss also results in defects in the cell wall. Simultaneous mutations of these genes are lethal in Saccharomyces cerevisiae. To understand the basis of this synthetic lethality, we screened for multicopy suppressors and identified 13 SKG (suppressor of kex2 gas1 synthetic lethality) genes. SKG1 encodes a transmembrane protein that localizes on the inner surface of the plasma membrane at the bud and in the daughter cell. The multicopy SKG1 increases the sensitivity of cells to zymolyase, and the skg1Δ null mutation increases resistance to it. This zymolyase susceptibility corresponds to an increase of alkali‐soluble β‐1,3‐glucan and a decrease of chitin in the cell wall. Thus SKG1 encodes a novel protein that affects the cell wall polymer composition in the growing region of the cell. Copyright © 2005 John Wiley & Sons, Ltd.
Reproductive issues in adults with cystic fibrosis: Implications for genetic counseling
Authors: Lemke Amy
Published: January 2005

This article reviews reproductive issues faced by the growing number of individuals with cystic fibrosis (CF) who reach adulthood. Approximately 97–98% of males with CF are infertile and they may have an increased risk for genitourinary anomalies. Females with CF may experience delayed puberty, irregular menstrual cycles, and decreased fertility. Women with CF who have good clinical scores, good nutritional status, and normal lung volumes with mild to moderate airway obstruction, have a better chance for successful pregnancies. The role of the genetic counselor in counseling adults with CF is discussed and resources for CF adults are provided.
The twisted helix: An essay on genetic counselors, eugenics, and social responsibility
Authors: Resta Robert G.
Published: January 2005

The American eugenics movement had a significant impact on American social history, and analysis of the movement illustrates the relationship among science, scientists, and society. The history of the American eugenics movement as well as more recent examples of eugenic thought and biological determinism are reviewed. The need for genetic counselors to confront eugenic issues in their own profession and in society is discussed.
The utilization of genetic counselors within a newborn screening program
Authors: Bach Janice , Baker Diane , Naber John , Young William
Published: January 2005

Genetic counselors have participated in the Michigan Newborn Screening Program on a contractual basis since 1988. Their role includes newborn screening education and training, newborn nursery site visits, and monitoring newborn screening in hospitals. Their impact has been to improve the quality of newborn screening services by reducing errors and increasing completion of data fields on newborn screening cards, improving hospital nursery cooperation and problem solving, and enhancing health department response to specific problems.
An educational program to overcome language and cultural barriers to genetic services
Authors: Dixson Barbara , Dang Vi , Cleveland James O. , Peterson Raymond M.
Published: January 2005

Providing genetic services to families who do not speak English and whose cultures are quite diverse presents a unique challenge to genetic specialists. One approach that is being employed successfully is the use of specially trained genetic assistants to provide outreach, case finding, referral, support, interpretation, advocacy, and follow‐up counseling. A basic genetic assistant training program for five bicultural/bilingual Southeast Asian case managers is described. The course syllabus can be used to train health workers who represent a variety of cultures and languages.
Social Support Mediates the Effects of Dual‐Focus Mutual Aid Groups on Abstinence from Substance Use
Authors: Laudet Alexandre B. , Cleland Charles M. , Magura Stephen , Vogel Howard S. , Knight Edward L.
Published: January 2005

Background: Specialized 12‐step based groups have emerged to address the needs of persons recovering from both substance abuse and psychiatric illness. Objective: This study investigates the role of social support in mediating the association between mutual aid participation and subsequent substance use for dually diagnosed persons. Method: A cohort of Double Trouble in Recovery (DTR) members in New York City were studied prospectively over a two‐year period. Findings: Longer DTR participation during the first year of the study was associated with lower substance use in the second year; that effect was partially explained by the maintenance of high level of social support. Conclusion: These findings speak of the enduring influence of 12‐step attendance on reducing substance use, and underline the importance of both 12‐step attendance and supportive networks for dually diagnosed persons.
The Contributions of Community, Family, and School Variables to Student Victimization
Authors: Khoury-Kassabri Mona , Benbenishty Rami , Avi Astor Ron , Zeira Anat
Published: January 2005

An ecological perspective was used to predict school violence from a number of variables describing the students and their families based on nationally representative sample of 10,400 students in grades 7–11 in 162 schools across Israel. Self‐administered anonymous questionnaires that included a scale for reporting victimization by serious and moderate physical violence, threats, and verbal–social victimization were filled out during class. Hierarchical linear modeling (HLM) examined the relationships between students’ reports of victimization and student level variables (gender, age) and the school‐level variables—cultural affiliation (Jewish vs. Arab), the socio‐economic status (SES) of the school's neighborhood and students’ families, school and class size, school level (junior high vs. high), and school climate. Variance between schools accounted for 9–15% of the variance in student victimization (major factors being school climate characteristics and percent of boys at the school). Boys reported higher victimization than girls for all forms of school violence. Students in junior high schools reported more victimization than high school students. Higher levels of victimization were reported in overcrowded classes, while school size was not associated with students’ reports of victimization. Although there were almost no differences between Jewish and Arab schools in students’ reports of victimization, the SES of the school's neighborhood and students did have a moderate effect. The discussion highlights the importance of improving school climate and the need to allocate more resources to schools in low SES contexts in order to protect students from school violence.
The Relationship Between Perceptions of Neighborhood Characteristics and Substance Use Among Urban African American Adolescents
Authors: Lambert Sharon F. , Brown Tamara L. , Phillips Clarenda M. , Ialongo Nicholas S.
Published: January 2005

Although the neighborhood microsystem is recognized as an important domain for adolescent development, relative to the family and peer contexts, neighborhood factors have been understudied in relation to adolescent substance abuse. In addition, recent research suggests that risk factors for adolescent substance use may differ for African Americans when compared to Caucasian youth. This study investigated the association between perceived neighborhood disorganization and later substance use, as well as possible mediators of that association, among a community sample of urban African American adolescents. Perceptions of neighborhood disorganization (i.e., violence/safety and drug activity) in grade 7 were associated with increased tobacco, alcohol, and marijuana use in grade 9. For females, this association was mediated by attitudes about drug use and perceptions of drug harmfulness. Findings highlight the importance of neighborhood contextual variables for African American substance use. Implications and directions for future research are presented.
Delinquency and Substance Use among Gang‐Involved Youth: The Moderating Role of Parenting Practices
Authors: Walker-Barnes Chanequa J. , Mason Craig A.
Published: January 2005

This study uses longitudinal data from an ethnically diverse sample of 300 ninth grade students to examine the moderating effect of parenting practices upon the relationship between gang involvement and adolescent problem behavior. Results of hierarchical linear modeling indicate that gang involvement is a highly significant positive predictor of each of three categories of problem behavior (minor delinquency, major delinquency, and substance use). Three of the four parenting variables (behavioral control, psychological control, parent–adolescent conflict, and warmth) are found to moderate the relationship between gang involvement and problem behavior, with the most consistent effects found for behavioral control and warmth. These findings indicate that intervention efforts aimed at reducing the impact of gang involvement on adolescent development should consider factors that may decrease the deleterious behavioral outcomes associated with youth gangs.
Central and peripheral neurochemical alterations and immune effects of prenatal ethanol exposure in rats
Authors: Clausing Peter , Ali Syed F. , Taylor Laventrice D. , Newport Glenn D. , Rybak Susanne , Paule Merle G.
Published: January 2005

In contrast to the well known effects of prenatal ethanol exposure on the central nervous system, data about its peripheral effects are scarce. Here, Sprague‐Dawley rats were fed a liquid diet (gestational days 0–20) containing 36% ethanol‐derived calories (EDCs, group H) or were pair‐fed with 18% EDCs (group L) or 0% EDCs (group C. On postnatal day 20, one male and one female from each of 10 litters per group were killed. Norepinephrine (NE) was analyzed in the frontal cortex, spleen and thymus, and dopamine, 5‐hydroxytryptamine (serotonin, 5‐HT) and their metabolites 3,4‐dihydroxyphenylacetic acid, homovanillic acid (HVA) and 5‐hydroxyindoleacetic acid (5‐HIAA) were analyzed in the striatum by high‐performance liquid chromatography with electrochemical detection. Lymphocyte subpopulations in the spleen and thymus were also assessed in half of these litters. Significant decreases in splenic NE concentration were seen in both sexes of group H (males 27%, females 28%). Decreases in striatal 5‐HT and 5‐HIAA of group H subjects appeared to be sex specific (only females were significantly affected: 23% decrease in 5‐HT, 37% decrease in 5‐HIAA). Pronounced, dose‐dependent reductions in T cell percentages were observed in both the thymus and spleen. Splenic CD8+and CD4+cell percentages were positively correlated with the splenic NE concentrations. It is concluded that the decreases seen in splenic T cell percentages subsequent to prenatal ethanol exposure may be caused, at least partially, by impaired noradrenergic control of this organ.
DiI labeling and homeobox gene Islet‐1 expression reveal the contribution of ventral neural tube cells to the formation of the avian trigeminal ganglion
Authors: Sohal G.S. , Bockman D.E. , Ali M.M. , Tsai N.T.
Published: January 2005

Cells of the neural tube are thought to be committed to form only the central nervous system, whereas the peripheral nervous system is believed to be derived from neural crest cells and from placodes, which are specialized regions of the surface ectoderm. Neural crest cells arise early from the dorsal part of the neural tube. The possibility that after emigration of the neural crest cells, another population of cells arising from the ventral part of the neural tube also emigrates via a different route was examined. Here we report that, after labeling cells of the ventral neural tube in the rostral hindbrain of E3 duck embryos with DiI, they were later found in the trigeminal ganglion of the fifth cranial nerve. A trail of labeled cells could be traced from the ventral part of the neural tube to the peripheral ganglion. Further, expression of the homeobox gene Islet‐1 in cells of the neural tube and the ganglion also indicated that some ventral neural tube cells may normally emigrate to the trigeminal ganglion. It is concluded that not all neural tube cells are committed to form the central nervous system; the ventral part of the neural tube also provides cells for the formation of the trigeminal ganglion. These results raise the possibility that the ventral neural tube may serve as an additional source of cells for the formation of various other components of the peripheral nervous system.
Structural plasticity of the adult CNS. Negative control by neurite growth inhibitory signals
Authors: Schwab Martin E.
Published: January 2005

The neuronal network of the adult central nervous system (CNS) retains a limited capacity for growth and structural change. This structural plasticity has been best studied in the context of lesion‐induced growth and repair. More recently, structural changes underlying functional plasticity occurring under specific physiological conditions have also been documented, in particular in the cortex and the hippocampus. Areas known for their adult plastic potential retain high levels of the growth associated protein GAP‐43, suggesting a persistence of important components of the intracellular growth machinery throughout life. Interestingly, a pronounced negative correlation exists between the levels of GAP‐43 and myelination in the adult CNS. Because CNS myelin contains potent neurite growth inhibitory membrane proteins, neurite growth, sprouting and plasticity were investigated in the spinal cord and brain in areas where oligodendrocyte development and myelin formation was experimentally prevented, or in the presence of an inhibitor neutralizing antibody (mAB‐IN‐1). In all areas, lesion‐induced or spontaneous sprouting was enhanced, in parallel with persistent high levels of GAP‐43. Thus, spontaneous sprouting of side branches occurred from retinal axons in the optic nerve in the absence of myelin, and target‐deprived retinal axons showed increased sprouting and innervation of the contralateral optic tectum in the presence of mAB IN‐1. In experimentally myelin‐free spinal cords collaterals from intact dorsal roots grew over long distances to innervate deafferented target regions following the section of three dorsal roots. Similarly, the corticospinal tract sprouted across the the midline and re‐established a dense plexus of fibres on the contralateral side of the spinal cord following section of one corticospinal tract in juvenile rats. Following bilateral dorsal hemisection of the spinal cord including both corticospinal tracts in young and adult rats, long distance regeneration of corticospinal fibres leading to significant functional improvements of locomotion and certain reflexes was induced by the neurite growth inhibitor neutralizing antibody IN‐1.