bluuebunny/crossref_metadata_2025_split huggingface dataset:
Action of Chlorhexidine Digluconate against Yeast and Filamentous Forms in an Early-StageCandida albicansBiofilm
Authors: Suci Peter A. , Tyler Bonnie J. 
Published: October 2002

ABSTRACTAn in situ method for sensitive detection of differences in the action of chlorhexidine against subpopulations of cells inCandida albicansbiofilms is described. Detection relies on monitoring the kinetics of propidium iodide (PI) penetration into the cytoplasm of individual cells during dosing with chlorhexidine. Accurate estimation of the time for delivery of the dosing concentration to the substratum was facilitated by using a flow cell system for which transport to the interfacial region was previously characterized. A model was developed to quantify rates of PI penetration based on the shape of the kinetic data curves. Yeast were seeded onto the substratum, and biofilm formation was monitored microscopically for 3 h. During this period a portion of the yeast germinated, producing filamentous forms (both hyphae and pseudohyphae). When the population was subdivided on the basis of cell morphology, rates of PI penetration into filamentous forms appeared to be substantially higher than for yeast forms. Based on the model, rates of penetration were assigned to individual cells. These data indicated that the difference in rates between the two subpopulations was statistically significant (unpairedttest,P< 0.0001). A histogram of rates and analysis of variance indicated that rates were approximately equally distributed among different filamentous forms and between apical and subapical segments of filamentous forms.
Cationic Hydrophobic Peptides with Antimicrobial Activity
Authors: Stark Margareta , Liu Li-Ping , Deber Charles M. 
Published: October 2002

ABSTRACT
The MICs of cationic, hydrophobic peptides of the prototypic sequence KKAAAXAAAAAXAAWAAXAAAKKKK-amide (where X is one of the 20 commonly occurring amino acids) are in a low micromolar range for a panel of gram-negative and gram-positive bacteria, with no or low hemolytic activity against human and rabbit erythrocytes. The peptides are active only when the average segmental hydrophobicity of the 19-residue core is above an experimentally determined threshold value (where X is Phe, Trp, Leu, Ile, Met, Val, Cys, or Ala). Antimicrobial activity could be increased by using peptides that were truncated from the prototype length to 11 core residues, with X being Phe and with 6 Lys residues grouped at the N terminus. We propose a mechanism for the interaction between these peptides and bacterial membranes similar to the “carpet model,” wherein the Lys residues interact with the anionic phospholipid head groups in the bacterial membrane surface and the hydrophobic core portion of the peptide is then able to interact with the lipid bilayer, causing disruption of the bacterial membrane.
Tripeptide Interference with Human Immunodeficiency Virus Type 1 Morphogenesis
Authors: Höglund Stefan , Su Jin , Reneby Sara Sandin , Végvári Ákos , Hjertén Stellan , Sintorn Ida-Maria , Foster Hillary , Wu Yi-Pyng , Nyström Ingela , Vahlne Anders 
Published: October 2002

ABSTRACTCapsid assembly during virus replication is a potential target for antiviral therapy. The Gag polyprotein is the main structural component of retroviral particles, and in human immunodeficiency virus type 1 (HIV-1), it contains the sequences for the matrix, capsid, nucleocapsid, and several small polypeptides. Here, we report that at a concentration of 100 μM, 7 of 83 tripeptide amides from the carboxyl-terminal sequence of the HIV-1 capsid protein p24 suppressed HIV-1 replication (>80%). The three most potent tripeptides, glycyl-prolyl-glycine-amide (GPG-NH2), alanyl-leucyl-glycine-amide (ALG-NH2), and arginyl-glutaminyl-glycine-amide (RQG-NH2), were found to interact with p24. With electron microscopy, disarranged core structures of HIV-1 progeny were extensively observed when the cells were treated with GPG-NH2and ALG-NH2. Furthermore, nodular structures of approximately the same size as the broad end of HIV-1 conical capsids were observed at the plasma membranes of treated cells only, possibly indicating an arrest of the budding process. Corresponding tripeptides with nonamidated carboxyl termini were not biologically active and did not interact with p24.
Class 1 Integron-Associated Tobramycin-Gentamicin Resistance in
Campylobacter jejuni
Isolated from the Broiler Chicken House Environment
Authors: Lee Margie D. , Sanchez Susan , Zimmer Martha , Idris Umelaalim , Berrang Mark E. , McDermott Patrick F. 
Published: October 2002

ABSTRACT

Using PCR, we screened 105 isolates of poultry-associated
Campylobacter jejuni
for the presence of class 1 integrons. Of those isolates, 21% (22 of 105) possessed the integrase gene, but only 5 isolates produced an amplicon in a 5′-3′ conserved sequence PCR directed toward amplification of the resistance cassettes. DNA sequencing demonstrated that all five isolates possessed the aminoglycoside resistance gene,
aacA4
.
Immunomodulatory drug CC-5013 overcomes drug resistance and is well tolerated in patients with relapsed multiple myeloma
Authors: Richardson Paul G. , Schlossman Robert L. , Weller Edie , Hideshima Teru , Mitsiades Constantine , Davies Faith , LeBlanc Richard , Catley Laurence P. , Doss Deborah , Kelly Kathleen , McKenney Mary , Mechlowicz Julie , Freeman Andrea , Deocampo Reggie , Rich Rebecca , Ryoo Joan J. , Chauhan Dharminder , Balinski Kathe , Zeldis Jerome , Anderson Kenneth C. 
Published: October 2002

AbstractThalidomide (Thal) can overcome drug resistance in multiple myeloma (MM) but is associated with somnolence, constipation, and neuropathy. In previous in vitro studies, we have shown that the potent immunomodulatory derivative of thalidomide (IMiD) CC-5013 induces apoptosis or growth arrest even in resistant MM cell lines and patient cells, decreases binding of MM cells to bone marrow stromal cells (BMSCs), inhibits the production in the BM milieu of cytokines (interleukin-6 [IL-6], vascular endothelial growth factor [VEGF], tumor necrosis factor-α [TNF-α]) mediating growth and survival of MM cells, blocks angiogenesis, and stimulates host anti-MM natural killer (NK) cell immunity. Moreover, CC-5013 also inhibits tumor growth, decreases angiogenesis, and prolongs host survival in a human plasmacytoma mouse model. In the present study, we carried out a phase 1 CC-5013 dose-escalation (5 mg/d, 10 mg/d, 25 mg/d, and 50 mg/d) study in 27 patients (median age 57 years; range, 40-71 years) with relapsed and refractory relapsed MM. They received a median of 3 prior regimens (range, 2-6 regimens), including autologous stem cell transplantation and Thal in 15 and 16 patients, respectively. In 24 evaluable patients, no dose-limiting toxicity (DLT) was observed in patients treated at any dose level within the first 28 days; however, grade 3 myelosuppression developed after day 28 in all 13 patients treated with 50 mg/d CC-5013. In 12 patients, dose reduction to 25 mg/d was well tolerated and therefore considered the maximal tolerated dose (MTD). Importantly, no significant somnolence, constipation, or neuropathy has been seen in any cohort. Best responses of at least 25% reduction in paraprotein occurred in 17 (71%) of 24 patients (90% confidence interval [CI], 52%-85%), including 11 (46%) patients who had received prior Thal. Stable disease (less than 25% reduction in paraprotein) was observed in an additional 2 (8%) patients. Therefore, 17 (71%) of 24 patients (90% CI, 52%-85%) demonstrated benefit from treatment. Our study therefore provides the basis for the evaluation of CC-5013, either alone or in combination, to treat patients with MM at earlier stages of disease.
Expression of rat complement control protein Crry on tumor cells inhibits rat natural killer cell–mediated cytotoxicity
Authors: Caragine Theresa A. , Imai Masaki , Frey Alan B. , Tomlinson Stephen 
Published: October 2002

AbstractCrry is a rodent membrane–bound inhibitor of complement activation and is a structural and functional analog of the human complement inhibitors decay-accelerating factor and membrane cofactor protein. We found previously that expression of rat Crry on a human tumor cell line enhances tumorigenicity in nude rats. In this study, we investigated the effect that rat Crry expressed on tumor cells has on rat cell–mediated cytotoxicity and antibody-dependent cell-mediated cytotoxicity (ADCC). The expression of rat Crry on the surface of different human tumor cell lines inhibited ADCC mediated by rat natural killer (NK) cells. C3 opsonization is known to enhance NK cell–mediated cytolysis, and a potential mechanism for Crry-mediated inhibition of NK cell lysis is through Crry modulation of C3 deposition on target cells. However, the transfection of tumor cell lines with Crry enhanced their resistance to NK cell–mediated lysis in the absence of exogenous complement. The resistance of Crry-expressing tumor cells to NK cell–mediated ADCC could be reversed by treatment with anti–Crry F(ab)2. In addition, anti–Crry F(ab)2 enhanced the susceptibility of 13762 rat mammary adenocarcinoma cells (that endogenously express Crry) to ADCC mediated by allogeneic rat NK cells in the absence of added complement. We found no evidence that rat NK cells were a source of complement for target cell deposition during the in vitro cytolysis assay. These data suggest a novel function for rat Crry in tumor immune surveillance that may be unrelated to complement inhibition.
Cytosolic pH and the inflammatory microenvironment modulate cell death in human neutrophils after phagocytosis
Authors: Coakley Raymond J. , Taggart Clifford , McElvaney Noel G. , O'Neill Shane J. 
Published: October 2002

AbstractFollowing phagocytosis in vivo, acidification of extracellular pH (pHo) and intracellular metabolic acid generation contribute to cytosolic proton loading in neutrophils. Cytosolic pH (pHi) affects neutrophil function, although its regulation is incompletely understood. Its effect on mechanisms of neutrophil death is also uncertain. Thus, we investigated pHi regulation in Escherichia coli–exposed neutrophils, at various pathogen-to-phagocyte ratios (0:1-50:1), under conditions simulating the inflammatory milieu in vivo and correlated pHi changes with mechanisms of neutrophil death. Following phagocytosis, proton extrusion was dominated early by passive proton conductance channels, and later by Na+/H+ exchange (NHE). H+-translocating adenosine triphosphatase (V-ATPase) pHi regulation was evident primarily at lower bacterial densities. At physiologic pHo, lower pathogen-to-phagocyte ratios alkalinized pHi and inhibited apoptosis, whereas higher ratios acidified pHi (despite proton extrusive mechanisms) and promoted apoptosis. Necrosis was induced by high-density bacterial exposure at reduced pHo. Following phagocytosis, targeted inhibition of NHEs, proton conductance channels, or V-ATPases (amiloride, ZnCl2, or bafilomycin, respectively) moderately hyperacidified pHi and accelerated apoptosis. However, in combination they profoundly acidified pHi and induced necrosis. Proinflammatory mediators in vivo might affect both pHi regulation and cell death, so we tested the effects of bronchoalveolar lavage (BAL) fluid from patients with cystic fibrosis (CF) and healthy subjects. Only CF BAL fluid alkalinized pHi and suppressed apoptosis at physiologic pHo, but failed to prevent necrosis following phagocytosis at low pHo. Thus, a precarious balance between cytosolic proton loading and extrusion after phagocytosis dictates the mode of neutrophil cell death. pHi/pHo might be therapeutically targeted to limit neutrophil necrosis and protect host tissues during necrotizing infections.
Chronic lymphocytic leukemia preceded by cold agglutinin disease: intraclonal immunoglobulin light-chain diversity inVH4-34 expressing single leukemic B cells
Authors: Ruzickova Sarka , Pruss Axel , Odendahl Marcus , Wolbart Karsten , Burmester Gerd-Rüdiger , Scholze Jürgen , Dörner Thomas , Hansen Arne 
Published: October 2002

AbstractAutoimmune phenomena may precede or accompany lymphoid malignancies, especially B-chronic lymphocytic leukemia (B-CLL). We report a patient with a 7-year history of primary (idiopathic) cold agglutinin (CA) disease in whom B-CLL subsequently developed. Immunophenotyping and single-cell reverse transcription–polymerase chain reaction (RT-PCR) were applied to investigate the origin and diversification of leukemic B cells. The obtained data indicate a memory cell-type origin of the B-CLL cells. Remarkably, theIgVκ genes of the B-CLL cells showed intraclonal diversity, whereas the mutational pattern of their paired IgVH genes were invariant. Thus, the light-chain–restricted intraclonal diversity in individual leukemic B cells in this patient strongly indicates a differential regulation or selection of the ongoing mutational process. Of note, our findings suggest that this B-CLL had developed from the patient's CA-producing B-cell population.
Electrochemical Reduction and Differential Pulse Polarographic Determination of Butralin and Isopropalin in Environmental Samples at a Mercury Electrode
Authors: Sreedhar Mallipattu , Reddy Srinivasulu Jayarama 
Published: October 2002

Abstract
The electrochemical reduction behavior of two dinitroaniline herbicides, Butralin (BN) and Isopropalin (IN), at a mercury electrode is described based on different voltammetric techniques in various buffer solutions at different pH values. The nature of the electrode process has been examined. A reduction mechanism was proposed. Britton–Robinson (BR) buffer of pH 4.0 was found to be best media for the analysis of the compounds. Both standard addition and calibration methods were used for analysis. The detection limits were found to be 6 × 10−8 M (M = mol dm−3) for BN and for 1.5 × 10−8 M for IN. A differential pulse polarographic method was developed for the determination of the herbicides in grains and soils as well as water samples.
Application and validation of a urinary methadone metabolite (EDDP) immunoassay to monitor methadone compliance
Authors: George S , Parmar S , Meadway C , Braithwaite R A 
Published: October 2002

A total of 1381 urine specimens were screened using a Microgenics CEDIA urinary primary methadone metabolite (2-ethylidene-1,5-dimethyl-3,3- diphenylpyrrolidine; EDDP) immunoassay (cut-off calibrator concentration of 100 µg/L) in combination with a Dade Behring EMIT urinary methadone immunoassay (cut-off calibrator concentration of 300 µg/L). Of these, 642 (46%) were found to be positive using the EDDP assay but only 541 (39%) were found to be positive by the methadone assay. Out of the 108 specimens which were EDDP-positive but negative by the methadone assay, 47 (7%) could not be confirmed as positive using the routine in-house method of gas chromatography incorporating nitrogen-specific detection. Of these 47 results, 38 were re-screened using a more sensitive gas chromatography-mass spectrometry (GC-MS) technique, which demonstrated the presence of EDDP in every case. There was insufficient specimen to analyse the remaining nine samples. There were seven specimens which gave negative results by the EDDP and GC-MS assays but which had methadone concentrations ranging from 4000 to 37 500 µg/L. These were therefore presumed to be 'spiked' with methadone, i.e. to have had methadone added to the specimen to yield positive screening results and simulate compliance. It is concluded that the Microgenics CEDIA EDDP assay is a sensitive and reliable technique to determine the compliance of subjects prescribed methadone for opiate detoxification and maintenance.
Effects of renal sorbitol accumulation on urinary excretion of enzymes in hyperglycaemic rats
Authors: Ishii Naohito , Ikenaga Hideki , Ogawa Zensuke , Aoki Yoshikazu , Saruta Takao , Suga Tetsuya 
Published: October 2002

We studied the effects of epalrestat, a specific inhibitor of aldose reductase, on renal sorbitol accumulation and the resulting urinary enzyme excretion in hyperglycaemic rats. The activities of proximal tubule-derived enzymes such as N-acetyl- β-D-glucosaminidase (NAG), alanine aminopeptidase (AAP), γ-glutamyltranspeptidase (GGT) and dipeptidyl aminopeptidase IV (DAPIV) in urine were determined in five groups of male Wistar rats (each n=7): (a) 0·9% saline-loaded, (b) 10% glucose-loaded, (c) 10% glucose-loaded with epalrestat pretreatment, (d) 10% mannitol-loaded and (e) 10% mannitol-loaded with epalrestat pretreatment. Epalrestat was given mixed in chow at a dose of 50mg/kg body weight. Urinary NAG, AAP, GGT and DAPIV activities were significantly increased ( P<0·005, P<0·05, P<0·01, P<0·01, respectively) by the induction of hyperglycaemia. In contrast, enzyme excretion was not increased in the mannitol- or saline-loaded groups. Pre-treatment with epalrestat completely prevented the increased urinary excretion of NAG, AAP and GGT. At the end of the infusion study, renal cortical glucose concentrations of the glucose-loaded groups with and without epalrestat pretreatment were approximately fivefold higher than those of the mannitol- or saline-loaded groups ( P<0·005 each). Renal cortical sorbitol concentrations of the glucose-loaded group was also approximately twofold higher than those of the mannitol- or saline-loaded groups ( P<0·01 each). However, in the group that received both glucose and epalrestat, renal cortical sorbitol concentration was not increased. These results suggest that accumulation of intracellular sorbitol leads to proximal tubular cell dysfunction and abnormal enzymuria.
A simple high-pressure liquid chromatography cotinine assay: validation of smoking status in pregnant women
Authors: Greaves R , Trotter L , Brennecke S , Janus E 
Published: October 2002

Smoking during pregnancy is a significant public health issue, and studies of the effectiveness of interventions to reduce maternal smoking require accurate measurement of smoking status. This study addresses some key issues in improvement of the effectiveness and efficiency of chemical validation of smoking status using a simplified high-pressure liquid chromatography urine cotinine method. Urine samples were collected from pregnant women enrolled in a smoking cessation trial and from non-pregnant volunteers exposed to environmental tobacco smoke (ETS). Analysis of ETS samples produced a maximum cotinine of 28 µg/ mmol creatinine, which was established as the cut-off point for this method. This method is a relatively fast and inexpensive technique with which to analyse large batches of cotinine samples and can reliably measure smoking status.
Synthetic peptide-based electrochemiluminescence immunoassay for anti-Borna disease virus p40 and p24 antibodies in rat and horse serum
Authors: Yamaguchi Kazunari , Sawada Takashi , Yamane Sumitaka , Haga Seiichi , Ikeda Kazuhiko , Igata-Yi Ruriko , Yoshiki Keiko , Matsuoka Masao , Okabe Hiroaki , Horii Yoichiro , Nawa Yukifumi , Waltrip Royce W , Carbone Kathryn M 
Published: October 2002

Borna disease virus (BDV) is a neurotropic pathogen that infects a wide variety of vertebrates. We have developed a new electrochemiluminescence immunoassay (ECLIA) for the detection of antibodies to BDV, using three synthetic peptides corresponding to the amino acid residues 3-20 and 338-358 of p40 and 59-79 of p24 peptide of BDV. Using the ECLIA, we examined serum samples for the presence of anti-BDV antibodies in 20 rats (experimentally BDV-infected and uninfected) and 38 horses (13 US horses, experimentally infected and uninfected, and 25 Japanese horses, feral and domestic). The ECLIA, performed in a double-blind manner, detected anti-BDV antibodies in rats with a history of BDV infection, giving results that were in agreement with indirect immunofluorescence assay and/or Western blot (WB) analysis. The ECLIA also correctly identified all three experimentally infected horses and four domestic American horses that were seropositive for BDV antibodies by WB. Among the Japanese horses, at least two out of 10 feral and six out of 15 domestic horses were seropositive for BDV. In most of these cases, the specificity of immunoreactivity was verified by blocking with soluble p40 and p24 peptides.
Determination of plasma free carnitine by electrospray tandem mass spectrometry
Authors: Hardy David T , Preece Mary Anne , Green Anne 
Published: October 2002

We have evaluated a tandem mass spectrometry method for determining free carnitine concentrations in plasma and have compared its performance with that of an existing radioenzymatic assay. In this method, plasma was mixed with an internal standard, carnitine-d3 (600 nmol/L), and butylated before analysis on a Quattro II tandem mass spectrometer. The detection limit of the tandem mass spectrometric (MS) method was 4 µmol/L and carryover between samples was 2·2%. Precision of the method was 1·6-5·4% between injections and 4·0-5·6% between samples. Between-batch precision was 10-13%. The method was linear up to a free carnitine concentration of 300 µmol/L and good agreement was found with the existing radioenzymatic assay. We conclude that the tandem MS method is a precise and robust method for the determination of free carnitine concentrations in plasma that overcomes the disadvantages of the radiochemical method.
Effect of ageing on plasma lipoprotein(a) levels
Authors: Akita Harukuni , Matsubara Miyao , Shibuya Hitoshi , Fuda Hirotoshi , Chiba Hitoshi 
Published: October 2002

Background Lipoprotein(a) [Lp(a)] is a risk factor for atherosclerosis and increases with age. The purpose of this study was to determine the effect of ageing on Lp(a) for three different apo(a) phenotypes. Methods We measured plasma Lp(a) concentrations in 551 unrelated Japanese subjects (20-88 years of age). We performed statistical analyses separately for three apo(a) phenotypes: the low-molecular-weight (LMW) phenotype with the F, B or S1 isoform, the intermediate-molecular-weight (IMW) phenotype with the S2 isoform and the high-molecular-weight (HMW) phenotype with the S3 or S4 isoform. Results For each phenotype, the mean plasma Lp(a) concentration and the frequency of Lp(a) concentrations ≥ 250 mg/L increased with age. Further, a statistically significant difference was always found between the younger subjects (20-39 years of age) and the elderly (over 60 years). The frequency of coronary heart disease increased with age, particularly for the LMW and IMW phenotypes. Conclusions We conclude that ageing elevates plasma Lp(a) concentrations, which may have a role in the prevalence of coronary heart disease in the elderly, especially those with the LMW or IMW phenotypes.