bluuebunny/crossref_metadata_2025_split huggingface dataset:
Therapy and prophylaxis of inhaled biological toxins
Authors: Paddle Brian M. 
Published: June 2003

AbstractThis review highlights the current lack of therapeutic and prophylactic treatments for use against inhaled biological toxins, especially those considered as potential biological warfare (BW) or terrorist threats. Although vaccine development remains a priority, the use of rapidly deployable adjunctive therapeutic or prophylactic drugs could be life‐saving in severe cases of intoxication or where vaccination has not been possible or immunity not established. The current lack of such drugs is due to many factors. Thus, methods involving molecular modelling are limited by the extent to which the cellular receptor sites and mode of action and structure of a toxin need to be known. There is also our general lack of knowledge of what effect individual toxins will have when inhaled into the lungs — whether and to what extent the action will be cell speciﬁc and cytotoxic or rather an acute inﬂammatory response requiring the use of immunomodulators. Possible sources of speciﬁc high‐afﬁnity toxin antagonists being investigated include monoclonal antibodies, selected oligonucleotides (aptamers) and derivatized dendritic polymers (dendrimers). The initial selection of suitable agents of these kinds can be made using cytotoxicity assays involving cultured normal human lung cells and a range of suitable indicators. The possibility that a mixture of selected antibody, aptamer or dendrimer‐based materials for one or more toxins could be delivered simultaneously as injections or as inhaled aerosol sprays should be investigated. © Crown Copyright 2003. Reproduced with the permission of Her Majesty's Stationery Office. Published by John Wiley & Sons, Ltd.
Toxicity of cholesterol oxidation products to Caco‐2 and HepG2 cells: modulatory effects of α‐ and γ‐tocopherol
Authors: O'Sullivan A. J. , O'Callaghan Y. C. , Woods J. A. , O'Brien N. M. 
Published: June 2003

AbstractCholesterol can be oxidized to form a variety of cholesterol oxidation products also known as oxysterols. The aims of the present study were to compare the cytotoxic effects of four oxysterols, namely 25‐hydroxycholesterol (25‐OHC), 7β‐hydroxycholesterol (7β‐OHC), cholesterol‐5β,6β‐epoxide (β‐epox) and cholesterol‐5α,6α‐epoxide (α‐epox), in two human cell culture models. Further, the ability of 10 and 100 µm α‐ and γ‐tocopherol (α‐TOC and γ‐TOC, respectively) to protect against oxysterol‐induced cytotoxicity was also assessed. Human colonic adenocarcinoma Caco‐2 and human hepatoma HepG2 cells were supplemented with increasing concentrations of 25‐OHC, 7β‐OHC, β‐epox and α‐epox (0–25 µg ml−1) for 24, 48 or 96 h. Following 24‐h and 48‐h exposure, test media were replaced with normal growth media and the cells were maintained for 72 and 48 h, respectively. The 96‐h exposure represented a constant challenge to the cells. Cytotoxicity was assessed using the neutral red uptake assay. The concentration of compound that inhibited cell viability by 50% (ic50 value) was calculated. All four oxysterols investigated induced the greatest cytotoxic effects following 96 h of exposure. 25‐Hydroxycholesterol exhibited the greatest cytotoxicity in both cell lines. Both β‐epox and α‐epox were more toxic to HepG2 cells than to Caco‐2 cells after the 48‐h exposure. Pretreatment of cells with either α‐ or γ‐TOC did not protect against oxysterol‐induced cytotoxicity. The caco‐2 cells treated with the high concentration (100 µm) of γ‐TOC were found to be more susceptible to oxysterol‐induced toxicity under the conditions employed in this study. Copyright © 2003 John Wiley & Sons, Ltd.
Comparative study of total protein, and total and lipid‐associated serum sialic acid levels in patients with type 2 diabetes mellitus
Authors: Ekin Suat , Meral Ismail , Gunduz Handan , Mert Nihat 
Published: May 2003

AbstractThe aim of the present study was to investigate the serum total protein (TP), total sialic acid (TSA), lipid‐associated sialic acid (LSA), LSA/TP, and LSA/TP values in type 2 diabetes mellitus (DM) patients. Two study groups (healthy controls and type 2 DM subjects) were examined. For the type 2 DM group, 120 patients (60 females and 60 males) who had been diagnosed and treated for type 2 DM in the Yuzuncu Yil University Hospital, Van, Turkey, were selected consecutively. Forty healthy individuals (20 females and 20 males) were selected from hospital staff and other outpatient clinics to serve as the control group. They were matched for age, sex, body mass index, and smoking status. None of the participants had taken vitamin or mineral supplements for at least 2 weeks before sampling. To determine serum glucose, TP, TSA, and LSA levels, blood samples were drawn after all of the subjects fasted overnight. It was found that diabetics had higher TSA, LSA, TSA/TP, and LSA/TP levels than controls. However, the TP levels were not significantly different between the groups. Our results showed that TSA, LSA, TSA/TP, and LSA/TP have interactive connections with DM. These parameters can be used as a diagnostic index for patients with DM. J. Clin. Lab. Anal. 17:124–126, 2003. © 2003 Wiley‐Liss, Inc.
Chronic phase lipids in sera of chronic fatigue syndrome (CFS), chronic ciguatera fish poisoning (CCFP), hepatitis B, and cancer with antigenic epitope resembling ciguatoxin, as assessed with MAb‐CTX
Authors: Hokama Y. , Uto G.A. , Palafox N.A. , Enlander D. , Jordan E. , Cocchetto A. 
Published: May 2003

AbstractClinical reports and descriptions of chronic fatigue syndrome (CFS) and chronic ciguatera fish poisoning (CCFP) show great similarities in clinical symptomology. These similarities in the literature suggested the exploration of lipids in sera of CFS, CCFP, and other diseases with the membrane immunobead assay (MIA), which is typically used for screening ciguateric ocean fish. Sera from patients with other diseases, including hepatitis B, cancer, and diabetes, were included to assess the degree of specificity involved. Sera were treated with acetone in a ratio of 1 part serum to 4 parts acetone. The suspension was centrifuged, and the acetone layer was evaporated. The residue was weighed and redissolved in 1.0 mL methanol and tested by the MIA, undiluted and titered to 1:160. The undiluted acetone fraction of the 37 normal showed ± activity to +activity with 16 no titer, 15 with 1:5 titer and two with 1:10 titer, and four with ≥1:40 titers. One hundred fifteen CFS sera showed 1 with 1+ and 114 with 2+ activity in the undiluted samples, 1 with 1:10 titer, 3 with 1:20 titer, 31 with 1:40 titer, 50 with 1:80 titer, and 30 with 160 titer. Thus 95.6% of the samples had ≥1:40 titer. Eight hepatitis B sera samples had ≥1:40 titers. Four CCFP samples had ≥1:40 titers. Three of 16 cancer samples had 1:40 titer. These data are summarized in Fig. 1. As shown in Table 1, a significant increase (P<0.001) in the chronic phase lipids (CPLs) was shown relative to the normal group. A preliminary chemical study in C18 octadecylsilyl columns showed all fractions (100% chloroform, 9:1 chloroform : methanol, 1:1 chloroform : methanol, and 100% methanol) to contain lipids reactive to MAb‐CTX with different intensities. Prostaglandins were shown in 100% methanol fraction. Competitive MIA with crude fish ciguatoxin and CFS with synthetic JKLM ciguatoxin epitope suggested similarities in structure with ciguatoxin. This was compatible with the neuroblastoma assay demonstrated in the C18 column fractions 9:1 and 1:1, chloroform : methanol solvents. J. Clin. Lab. Anal. 17:132–139, 2003. Copyright © 2003 John Wiley & Sons, Ltd.
Analysis of urinary N‐acetyl‐β‐D‐glucosaminidase using 2,4‐dinitrophenyl‐1‐thio N‐acetyl‐β‐D‐glucosaminide as the substrate
Authors: Yamada Magohei , Fujita Toshio 
Published: May 2003

Abstract2,4‐Dinitrophenyl‐1‐thio N‐acetyl‐β‐D‐glucosaminide was examined as a new substrate for analyzing the level of N‐acetyl‐β‐D‐glucosaminidase in the urine of patients suffering from renal diseases. The analysis is based on the fact that the substrate, when hydrolyzed in the presence of N‐acetyl‐β‐D‐glucosaminidase, liberates 2,4‐dinitrothiophenol as the chromogen. The optimum pH for the enzyme reaction is 4.6, which is covered by the optimal range for the UV absorbance of the chromogen. The first‐order rate of increase of the absorbance at this pH was linear to the enzyme concentration up to 600 U/L, with a high sensitivity. Analytical reagents with glucosaminides of 2,4‐dinitrophenol and 2‐chloro‐4‐nitrophenol are less stable than the reagent with glucosaminide of 2,4‐dinitrothiophenol. The optimum pH for the absorbance of p‐nitrophenol and 2‐chloro‐4‐nitrophenol does not match that for the enzyme reaction. J. Clin. Lab. Anal. 17:127–131, 2003. © 2003 Wiley‐Liss, Inc.
Cell‐free DNA is released from tumor cells upon cell death: A study of tissue cultures of tumor cell lines
Authors: Li Chia‐Ni , Hsu Hui‐Lun , Wu Tsu‐Lan , Tsao Kuo‐Chien , Sun Chien‐Feng , Wu James T. 
Published: May 2003

AbstractTo determine the source of cell‐free DNA detected in the serum of cancer patients, we monitored the release of cell‐free DNA and tumor markers from tumor cell lines using the cell culture technique. During the first 6 days of cell culture, we found very low concentrations of DNA and a steady increase of the CA 125 released from the SK‐BR3 tumor cell lines during cell growth. A sudden increase of cell‐free DNA detected in the cell medium coincided with cell death. As the cells died, the concentration of cell‐free DNA declined but the concentration of CA 125 increased. The sudden release of cell‐free DNA observed upon cell death was also found on the cell cultures of additional tumor cell lines, including A549, RD, and SK‐N‐SH cells. It appears that the majority of cell‐free DNA detected in the serum of cancer patients comes from tumor cells following cell death and cell necrosis. The concentration of cell‐free DNA released is related to the number of dead cells, whereas that of the tumor marker CA 125 is associated with the presence of the total number of cells (dead or alive). J. Clin. Lab. Anal. 17:103–107, 2003. © 2003 Wiley‐Liss, Inc.
Multiplex PCR: Rapid DNA cycling in a conventional thermal cycler
Authors: Markoulatos P. , Siafakas N. , Katsorchis T. , Moncany M. 
Published: May 2003

AbstractMultiplex polymerase chain reaction (PCR) is a variant of PCR in which two or more target sequences are simultaneously amplified in the same reaction. In the present study we investigated the limits to which the duration of multiplex PCR steps can be shortened using the thermal cycler Gene Amp PCR system 9600 (Perkin Elmer, Oak Brook, IL). The present multiplex PCR assay simultaneously detects five different herpes viruses (HSV‐1, HSV‐2, VZV, CMV, and EBV) and assesses sample suitability in a single amplification round of 40 cycles. It appears that when six target sequences are simultaneously amplified in multiplex PCR, extension time is a critical parameter. Using a PCR protocol of 0 sec at 95°C, 0 sec at 60°C, and 0 sec at 74°C with Platinum Taq DNA polymerase (Life Technologies, Gaithersburg, MD), we were able to reduce the total cycling time of the multiplex PCR assay to as little as 55 min, without affecting the yield of PCR products or the specificity of the assay. It may be necessary to optimize each specific apparatus and template, but any such optimization would be trivial. J. Clin. Lab. Anal. 17:108–112, 2003. © 2003 Wiley‐Liss, Inc.
Evaluation of the Sysmex Xe‐2100® hematology analyzer in hospital use
Authors: Nakul‐Aquaronne Danièle , Sudaka‐Sammarcelli Isabelle , Ferrero‐Vacher Corinne , Starck Benoit , Bayle Jacques 
Published: May 2003

AbstractThe Sysmex XE‐2100® (Sysmex Corp. Kobe, Japan) is a latest‐generation hematology analyzer. Its optical and electrical measuring technology is improved by the addition of flux cytometry, fluorescence, and differential lysis. Its analytical performance in terms of precision, reproducibility, linearity, carryover, and time stability was found to be entirely satisfactory. In addition, the results of 500 complete blood counts and differentials correlated perfectly with those obtained by the Coulter STKS® (Beckman Coulter, Villapointe, France). The comparison of 500 leukocyte differential count results analyzed in parallel with optical microscopy and the XE‐2100® were surprising, and favorable to the XE‐2100®. This analyzer provides the user with an undeniable feeling of security concerning its reliability in detecting and identifying anomalies in the automated leukocyte differential count. With a sensitivity of 96%, a negative predictive value (NPV) of 98%, and a false‐negative (FN) rate of 4%, the XE‐2100® has perhaps reached the technological limits for a machine performing morphological recognition of normal and pathological blood cells. J. Clin. Lab. Anal. 17:113–123, 2003. © 2003 Wiley‐Liss, Inc.
Influence of response factors on determining equilibrium association constants of non‐covalent complexes by electrospray ionization mass spectrometry
Authors: Gabelica Valérie , Galic Nives , Rosu Frédéric , Houssier Claude , De Pauw Edwin 
Published: June 2003

AbstractA method for determining the equilibrium association constant of a complexation reaction A + B ⇋ AB by electrospray ionization mass spectrometry is described. The method consists in measuring the relative intensities of the peaks corresponding to A and to AB in equimolar A–B solutions at different concentrations C0. The results are fitted by a non‐linear least‐squares procedure, with the two variable parameters being the equilibrium association constant Ka and a factor R, defined by I(AB)/I(A) = R × [AB]/[A]. The factor R is the ratio between the response factors of AB and A, and corrects for the relative electrospray responses of the complex and the free substrate A, mass discrimination of instrumental origin and/or moderate in‐source dissociation. The method is illustrated with the following two systems: complexes between a double‐stranded 12‐base pair oligonucleotide and minor groove binders, and cyclodextrin complexes with α,ω‐dicarboxylic acids. For the oligonucleotide complexes, it is found that the response of the complex is not dramatically different to the response of the free oligonucleotide duplex, as the double helix conformation is disturbed by the drug only to a minor extent. In the case of cyclodextrin complexes, these complexes were found to have a much higher response than free cyclodextrin. This may be due to the fact that cyclodextrin is neutral in solution, whereas the complex is charged, but it can also stem from the fact that a significant proportion of the complex is in a non‐inclusion geometry. The present method requires the exact determination of the concentrations of the reactants and is applicable to 1 : 1 complexes. Copyright © 2003 John Wiley & Sons, Ltd.
Monitoring of unfolding of metallo‐proteins by electrospray ionization mass spectrometry
Authors: Cunsolo Vincenzo , Foti Salvatore , La Rosa Carmelo , Saletti Rosaria , Canters G. W. , Verbeet M. Ph. 
Published: June 2003

AbstractAn electrospray ionisation (ESI) mass spectrometric method for the determination of the equilibrium constant and free energy (ΔG) of protein unfolding was used to monitor the denaturation process at different pH of three metallo‐proteins, i.e. wild‐type copper azurin, zinc azurin and wild‐type amicyanin. The time course of the unfolding process was followed by dissolving the proteins under denaturing conditions (methanol–water (1 : 1, v/v)) at different pH (2.5, 3.0, 3.5) and recording ESI spectra at time intervals. The spectra showed two series of peaks, corresponding to the native holo‐protein and the unfolded apo‐protein. From the intensity ratio of these two series of peaks at increasing time and at equilibrium, the equilibrium constants for the unfolding process for the three proteins could be determined. From these equilibrium constants a ΔG° derivation was attempted. The ΔG° values obtained decrease with decrease in pH, in agreement with the expected reduction of conformational stability of proteins at lower pH. The results obtained confirm that ESI‐MS can be used for monitoring of unfolding process and to derive quantitative thermodynamic data. Copyright © 2003 John Wiley & Sons, Ltd.
Low‐temperature SIMS mass spectra of diethyl ether
Authors: Kosevich Marina V. , Shelkovsky Vadim S. , Boryak Oleg A. , Gömöry Agnes , Végh Peter D. , Vékey Károly 
Published: June 2003

AbstractFor the first time a secondary ion mass spectrum of diethyl ether was obtained at low temperature. The spectrum recording became possible by carefully selecting the range of experimental conditions for the production of a cluster‐type spectrum. This range is specified by the threshold for spectrum appearance above the melting temperature of the frozen sample and a fairly short time span of existence of the liquid estimated as only a few minutes. The latter necessitates rather rapid spectrum detection. In practice, about 1 min was available for recording of the cluster‐type spectra. The secondary emission mass spectrum of diethyl ether appeared to be rich in peaks: along with abundant protonated clusters Mn·H+ (n = 1–12), unusually intense [Mn − H]+ and weaker Mn+· peaks were present accompanied by several sets of fragmented clusters, [Mn − 15]+, [Mn − 29]+, [Mn − 27]+, [Mn − 45]+, and monohydrates, Mn·H2O·H+. The analysis of all the peaks showed that the pattern of fragment clusters is qualitatively similar to the pattern of fragmentation of the diethyl ether molecular ion under high‐energy electron impact. The general features of the behaviour of diethyl ether under low‐temperature mass spectrometric conditions were similar to those observed earlier for some other organic solvents. Copyright © 2003 John Wiley & Sons, Ltd.
Volatile polydimethylcyclosiloxanes in the ambient laboratory air identified as source of extreme background signals in nanoelectrospray mass spectrometry
Authors: Schlosser Andreas , Volkmer‐Engert Rudolf 
Published: June 2003

AbstractPolydimethylcyclosiloxanes, an almost ubiquitous air contaminant, can interfere with nanoelectrospray analysis. The sensitivity of nanoelectrospray to these volatile air contaminants was demonstrated in this study. The intensity of the interfering ion signals caused by these compounds can be decreased by changing the position of the nanoESI needle and almost completely suppressed by applying a flow of pure nitrogen around the needle and the sample cone. The nitrogen flow causes a slight shift in charge distribution, but does not influence the sensitivity for peptide detection. Copyright © 2003 John Wiley & Sons, Ltd.
Decomposition of protein nitrosothiolsin matrix‐assisted laser desorption/ionization and electrospray ionization mass spectrometry
Authors: Kaneko Rina , Wada Yoshinao 
Published: June 2003

AbstractThe S‐nitrosylation of proteins is involved in the trafficking of nitric oxide (NO) in intra‐ and extracellular milieus. To establish a mass spectrometric method for identifying this post‐translational modification of proteins, a synthetic peptide and transthyretin were S‐nitrosylated in vitro and analyzed by electrospray ionization (ESI) and matrix‐assisted laser desorption/ionization (MALDI) mass spectrometry. The intact molecular ion species of nitrosylated compounds was identified in the ESI mass spectrum without elimination of the NO group. However, the labile nature of the S—NO bond was evident when the in‐source fragmentation efficiently generated [M + H − 30]+ ions. The decomposition was prominent for multiply charged transthyretin ions with high charge states under ordinary ESI conditions, indicating that the application of minimum nozzle potentials was essential for delineating the stoichiometry of nitrosylation in proteins. With MALDI, the S—NO bond cleavage occurred during the ionization process, and the subsequent reduction generated [M + H − 29]+ ions. Copyright © 2003 John Wiley & Sons, Ltd.
Mass spectrometric characterization of mitochondrial electron transport complexes: subunits of the rat heart ubiquinol–cytochrome c reductase
Authors: Sun Gang , Kinter Michael T. , Anderson Vernon E. 
Published: June 2003

AbstractComplex III of the mitochondrial electron transport chain, ubiquinol–cytochrome c reductase, was isolated by blue native polyacrylamide gel electrophoresis. Ten of the 11 polypeptides present in this complex were detected directly by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOFMS) following electroelution of the active complex. Tryptic and chymotryptic digestion of the complex permit the identification of specific peptides from all of the protein subunits with 70% coverage of the 250 kDa complex. The mass of all 11 proteins was confirmed by second dimension Tricine sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS‐PAGE) and elution of the separated polypeptides. Additionally, the identity of the core I, core II, cytochrome c and the Rieske iron–sulfur protein were confirmed by liquid chromatography/tandem mass spectrometry (LC/MS/MS) characterization of the peptides generated by in‐gel trypsin digestion of the SDS‐PAGE separated proteins. The methodology demonstrated for analyzing this membrane‐bound electron transport complex should be applicable to other membrane complexes, particularly the other mitochondrial electron transport complexes. The MS analysis of the peptides obtained by in‐gel digestion of the intact complex permits the simultaneous characterization of the native proteins and modifications that contribute to mitochondrial deficits that have been implicated as contributing to pathological conditions. Copyright © 2003 John Wiley & Sons, Ltd.
Fragmentation of dipyridamole and related dipyrimidines by electrospray ionization collisional activated decomposition mass spectrometry
Authors: Rodrigues Filho Edson , Almeida Adaila Marta Paixão , Tabak Marcel 
Published: June 2003

AbstractThe coronary vasodilator, co‐activator of antitumor compounds and antioxidant drug dipyridamole and several of its derivatives were studied by electrospray ionization (ESI) combined with collisional activated decomposition (CAD) in both positive and negative modes. These compounds produce abundant monocharged ions ([M + H]+) under ESI. Interpretation of the CAD spectra showed that fragmentation occurs preferentially in the ethanolamine groups attached at C‐2, C‐4, C‐6 and C‐8. 2‐Methoxyethanol is eliminated when ethanolamines are in positions C‐2/C‐6 and 2‐aziridinethanol is eliminated from C‐4/C‐8 ethanolamines. The proposed fragmentation schemes were supported by deuterium labeling experiments and tandem mass spectrometry. Copyright © 2003 John Wiley & Sons, Ltd.