bluuebunny/crossref_metadata_2025 huggingface dataset:
Structure of
Pfu
Pop5, an archaeal RNase P protein
Authors: Wilson Ross C. , Bohlen Christopher J. , Foster Mark P. , Bell Charles E.
Published: January 2006

We have used NMR spectroscopy and x-ray crystallography to determine the three-dimensional structure of PF1378 (
Pfu
Pop5), one of four protein subunits of archaeal RNase P that shares a homolog in the eukaryotic enzyme. RNase P is an essential and ubiquitous ribonucleoprotein enzyme required for maturation of tRNA. In bacteria, the enzyme's RNA subunit is responsible for cleaving the single-stranded 5′ leader sequence of precursor tRNA molecules (pre-tRNA), whereas the protein subunit assists in substrate binding. Although in bacteria the RNase P holoenzyme consists of one large catalytic RNA and one small protein subunit, in archaea and eukarya the enzyme contains several (≥4) protein subunits, each of which lacks sequence similarity to the bacterial protein. The functional role of the proteins is poorly understood, as is the increased complexity in comparison to the bacterial enzyme.
Pfu
Pop5 has been directly implicated in catalysis by the observation that it pairs with PF1914 (
Pfu
Rpp30) to functionally reconstitute the catalytic domain of the RNA subunit. The protein adopts an α–β sandwich fold highly homologous to the single-stranded RNA binding RRM domain. Furthermore, the three-dimensional arrangement of
Pfu
Pop5's structural elements is remarkably similar to that of the bacterial protein subunit. NMR spectra have been used to map the interaction of Pop5 with
Pfu
Rpp30. The data presented permit tantalizing hypotheses regarding the role of this protein subunit shared by archaeal and eukaryotic RNase P.
SNOSID, a proteomic method for identification of cysteine S-nitrosylation sites in complex protein mixtures
Authors: Hao Gang , Derakhshan Behrad , Shi Lei , Campagne Fabien , Gross Steven S.
Published: January 2006

Reversible addition of NO to Cys-sulfur in proteins, a modification termed S-nitrosylation, has emerged as a ubiquitous signaling mechanism for regulating diverse cellular processes. A key first-step toward elucidating the mechanism by which S-nitrosylation modulates a protein's function is specification of the targeted Cys (SNO-Cys) residue. To date, S-nitrosylation site specification has been laboriously tackled on a protein-by-protein basis. Here we describe a high-throughput proteomic approach that enables simultaneous identification of SNO-Cys sites and their cognate proteins in complex biological mixtures. The approach, termed SNOSID (SNO Site Identification), is a modification of the biotin-swap technique [Jaffrey, S. R., Erdjument-Bromage, H., Ferris, C. D., Tempst, P. & Snyder, S. H. (2001)
Nat. Cell. Biol.
3, 193–197], comprising biotinylation of protein SNO-Cys residues, trypsinolysis, affinity purification of biotinylated-peptides, and amino acid sequencing by liquid chromatography tandem MS. With this approach, 68 SNO-Cys sites were specified on 56 distinct proteins in
S
-nitrosoglutathione-treated (2–10 μM) rat cerebellum lysates. In addition to enumerating these S-nitrosylation sites, the method revealed endogenous SNO-Cys modification sites on cerebellum proteins, including α-tubulin, β-tubulin, GAPDH, and dihydropyrimidinase-related protein-2. Whereas these endogenous SNO proteins were previously recognized, we extend prior knowledge by specifying the SNO-Cys modification sites. Considering all 68 SNO-Cys sites identified, a machine learning approach failed to reveal a linear Cys-flanking motif that predicts stable transnitrosation by
S
-nitrosoglutathione under test conditions, suggesting that undefined 3D structural features determine S-nitrosylation specificity. SNOSID provides the first effective tool for unbiased elucidation of the SNO proteome, identifying Cys residues that undergo reversible S-nitrosylation.
Detachment of affinity-captured bioparticles by elastic deformation of a macroporous hydrogel
Authors: Dainiak Maria B. , Kumar Ashok , Galaev Igor Yu. , Mattiasson Bo
Published: January 2006

Adsorption of bioparticles to affinity surfaces involves polyvalent interactions, complicating greatly the recovery of the adsorbed material. A unique system for the efficient binding and release of different cells and particles is described. Affinity-bound bioparticles and synthetic particles are detached from the macroporous hydrogel matrix, a so-called cryogel, when the cryogel undergoes elastic deformation. The particle detachment upon elastic deformation is believed to be due to breaking of many of the multipoint attachments between the particles and the affinity matrix and the change in the distance between affinity ligands when the matrix is deformed. However, no release of affinity-bound protein occurred upon elastic deformation. The phenomenon of particle detachment upon elastic deformation is believed to be of a generic nature, because it was demonstrated for a variety of bioparticles of different sizes and for synthetic particles, for different ligand–receptor pairs (IgG–protein A, sugar–ConA, metal ion–chelating ligand), and when the deformation was caused by either external forces (mechanical deformation) or internal forces (the shrinkage of thermosensitive, macroporous hydrogel upon an increase in temperature). The elasticity of cryogel monoliths ensures high recovery of captured cells under mild conditions, with highly retained viability. This property, along with their continuous porous structure makes cryogel monoliths very attractive for applications in affinity cell separation.
Defining the sequence-recognition profile of DNA-binding molecules
Authors: Warren Christopher L. , Kratochvil Natasha C. S. , Hauschild Karl E. , Foister Shane , Brezinski Mary L. , Dervan Peter B. , Phillips George N. , Ansari Aseem Z.
Published: January 2006

Determining the sequence-recognition properties of DNA-binding proteins and small molecules remains a major challenge. To address this need, we have developed a high-throughput approach that provides a comprehensive profile of the binding properties of DNA-binding molecules. The approach is based on displaying every permutation of a duplex DNA sequence (up to 10 positional variants) on a microfabricated array. The entire sequence space is interrogated simultaneously, and the affinity of a DNA-binding molecule for every sequence is obtained in a rapid, unbiased, and unsupervised manner. Using this platform, we have determined the full molecular recognition profile of an engineered small molecule and a eukaryotic transcription factor. The approach also yielded unique insights into the altered sequence-recognition landscapes as a result of cooperative assembly of DNA-binding molecules in a ternary complex. Solution studies strongly corroborated the sequence preferences identified by the array analysis.
Gene expression profiles in acute myeloid leukemia with common translocations using SAGE
Authors: Lee Sanggyu , Chen Jianjun , Zhou Guolin , Shi Run Zhang , Bouffard Gerard G. , Kocherginsky Masha , Ge Xijin , Sun Miao , Jayathilaka Nimanthi , Kim Yeong Cheol , Emmanuel Neelmini , Bohlander Stefan K. , Minden Mark , Kline Justin , Ozer Ozden , Larson Richard A. , LeBeau Michelle M. , Green Eric D. , Trent Jeffery , Karrison Theodore , Liu Piu Paul , Wang San Ming , Rowley Janet D.
Published: January 2006

Identification of the specific cytogenetic abnormality is one of the critical steps for classification of acute myeloblastic leukemia (AML) which influences the selection of appropriate therapy and provides information about disease prognosis. However at present, the genetic complexity of AML is only partially understood. To obtain a comprehensive, unbiased, quantitative measure, we performed serial analysis of gene expression (SAGE) on CD15+myeloid progenitor cells from 22 AML patients who had four of the most common translocations, namely t(8;21), t(15;17), t(9;11), and inv(16). The quantitative data provide clear evidence that the major change in all these translocation-carrying leukemias is a decrease in expression of the majority of transcripts compared with normal CD15+cells. From a total of 1,247,535 SAGE tags, we identified 2,604 transcripts whose expression was significantly altered in these leukemias compared with normal myeloid progenitor cells. The gene ontology of the 1,110 transcripts that matched known genes revealed that each translocation had a uniquely altered profile in various functional categories including regulation of transcription, cell cycle, protein synthesis, and apoptosis. Our global analysis of gene expression of common translocations in AML can focus attention on the function of the genes with altered expression for future biological studies as well as highlight genes/pathways for more specifically targeted therapy.
Analysis of P53 mutations and their expression in 56 colorectal cancer cell lines
Authors: Liu Ying , Bodmer Walter F.
Published: January 2006

A comprehensive analysis of the
TP53
gene and its protein status was carried out on a panel of 56 colorectal cancer cell lines. This analysis was based on a combination of denaturing HPLC mutation screening of all exons of the p53 gene, sequencing the cDNA, and assessing the function of the p53 protein by assaying the induced expression of phosphorylated p53 and p21 after exposing cells to γ-rays. In a few cases where there was no production of p53 message nor evidence of functional p53 protein, all of the p53 exons were sequenced directly. Thirteen of the 56 cell lines had functional p53, 21 lines had missense mutations (one of which made no detectable protein), 4 lines produced no p53 transcripts, and the remaining 18 lines carried truncating
TP53
mutations. Thus, our results showed a relatively high frequency of
TP53
mutations (76.8%) in our cell lines, with almost half of the mutations being truncating mutations. This is a rather higher frequency of such mutations than usually reported. Of the 18 cell lines with truncating mutations, 12 had detectable truncated protein based on Western blot analysis, whereas no protein was detected in the remaining 6 cell lines. Our data provide a valuable source of
TP 53
mutations for further studies and raise the question of the extent to which truncating mutations may have dominant negative effects, even when no truncated protein can be detected by standard methods.
A virus-specific CD8+T cell immunodominance hierarchy determined by antigen dose and precursor frequencies
Authors: La Gruta Nicole L. , Kedzierska Katherine , Pang Ken , Webby Richard , Davenport Miles , Chen Weisan , Turner Stephen J. , Doherty Peter C.
Published: January 2006

Immunodominance hierarchies are a substantial, but poorly understood, characteristic of CD8+T cell-mediated immunity. Factors influencing the differential responses to the influenza A virus nucleoprotein (NP366–374) and acid polymerase (PA224–233) peptides presented by H2Dbhave been analyzed by disabling (N5→ Q substitution) these peptides in their native configuration, then expressing them in the viral neuraminidase protein. This strategy of shifting epitopes within the same viral context resulted in an apparent equalization of DbNP366[epitope consisting of viral nucleoprotein (NP) amino acid residues 366–374 complexed with the H2DbMHC class I glycoprotein] and DbPA224(H2Db+PA224–233) epitope abundance after direct infectionin vitroand induced reproducible changes in the magnitude of the DbNP366- and DbPA224-specific T cell subsets generated after infection of mice. Comparison of DbNP366- and DbPA224-specific CD8+T cell responses induced from the native configuration and from the viral neuraminidase stalk demonstrated that the size of both primary and secondary responses is influenced by relative epitope levels and that, at least after secondary challenge, the magnitude of responses is also determined by CD8+T cell precursor frequency. Thus, this immunodominance hierarchy is a direct function of antigen dose and T cell numbers.
Intrinsic kinetics determine the time course of neuronal synaptic transporter currents
Authors: Wadiche Jacques I. , Tzingounis Anastassios V. , Jahr Craig E.
Published: January 2006

Efficient clearance of synaptically released glutamate from the extracellular space is an absolute requirement for maintaining information processing in the central nervous system. In the cerebellum, clearance of glutamate relies on uptake by Bergmann glial cells and Purkinje cells (PCs). Uptake by PCs can be monitored by recording the synaptic transport current (STC) mediated by the PC-specific transporter excitatory amino acid transporter 4 (EAAT4). The slow time course of the PC STC has been used to argue that glutamate clearance is protracted. We find, however, that the time course of the STC is not affected by altering the amount of glutamate released at individual synapses or by partial transporter blockade, manipulations that would be expected to change the duration of the extracellular glutamate transient. Ion substitution experiments and kinetic modeling of the PC transporter current suggest that physiological levels of intracellular Na
+
and glutamate slow the cycling rate of transporters and thereby lengthen the time course of STCs. The model predicts that PC transporters bind glutamate quickly but that the actual cycling rate of EAAT4 in physiological conditions is slow; therefore, the STC reflects the intrinsic kinetics of the glutamate transporter, not the rate of glutamate clearance.
TRAIL-expressing T cells induce apoptosis of vascular smooth muscle cells in the atherosclerotic plaque
Authors: Sato Kayoko , Niessner Alexander , Kopecky Stephen L. , Frye Robert L. , Goronzy Jörg J. , Weyand Cornelia M.
Published: January 2006

Acute coronary syndromes (ACS) are precipitated by a rupture of the atherosclerotic plaque, often at the site of T cell and macrophage infiltration. Here, we show that plaque-infiltrating CD4 T cells effectively kill vascular smooth muscle cells (VSMC). VSMCs sensitive to T cell–mediated killing express the death receptor DR5 (TNF-related apoptosis-inducing ligand [TRAIL] receptor 2), and anti-TRAIL and anti-DR5 antibodies block T cell–mediated apoptosis. CD4 T cells that express TRAIL upon stimulation are expanded in patients with ACS and more effectively induce VSMC apoptosis. Adoptive transfer of plaque-derived CD4 T cells into immunodeficient mice that are engrafted with human atherosclerotic plaque results in apoptosis of VSMCs, which was prevented by coadministration of anti-TRAIL antibody. These data identify that the death pathway is triggered by TRAIL-producing CD4 T cells as a direct mechanism of VSMC apoptosis, a process which may lead to plaque destabilization.
Induction of APOBEC3 family proteins, a defensive maneuver underlying interferon-induced anti–HIV-1 activity
Authors: Peng Gang , Lei Ke Jian , Jin Wenwen , Greenwell-Wild Teresa , Wahl Sharon M.
Published: January 2006

Apolipoprotein B mRNA-editing enzyme-catalytic polypeptide-like 3G (APOBEC3G), a cytidine deaminase, is a recently recognized innate intracellular protein with lethal activity against human immunodeficiency virus (HIV). Packaged into progeny virions, APOBEC3G enzymatic activity leads to HIV DNA degradation. As a counterattack, HIV virion infectivity factor (Vif) targets APOBEC3G for proteasomal proteolysis to exclude it from budding virions. Based on the ability of APOBEC3G to antagonize HIV infection, considerable interest hinges on elucidating its mechanism(s) of regulation. In this study, we provide the first evidence that an innate, endogenous host defense factor has the potential to promote APOBEC3G and rebuke the virus-mediated attempt to control its cellular host. We identify interferon (IFN)-α as a potent inducer of APOBEC3G to override HIV Vif neutralization of APOBEC3 proteins that pose a threat to efficient macrophage HIV replication. Our data provide a new dimension by which IFN-α mediates its antiviral activity and suggest a means to render the host nonpermissive for viral replication.
Stoichiometry of the murine γδ T cell receptor
Authors: Hayes Sandra M. , Love Paul E.
Published: January 2006

The T cell receptor for antigen (TCR) complex is organized into two functional domains: the antigen-binding clonotypic heterodimer and the signal-transducing invariant CD3 and TCRζ chains. In most vertebrates, there are two different clonotypic heterodimers (TCRαβ and TCRγδ) that define the αβ and γδ T cell lineages, respectively. αβ- and γδTCRs also differ in their invariant chain subunit composition, in that αβTCRs contain CD3γε and CD3δε dimers, whereas γδTCRs contain only CD3γε dimers. This difference in subunit composition of the αβ- and γδTCRs raises the question of whether the stoichiometries of these receptor complexes are different. As the stoichiometry of the murine γδTCR has not been previously investigated, we used two quantitative immunofluorescent approaches to determine the valency of TCRγδ heterodimers and CD3γε dimers in surface murine γδTCR complexes. Our results support a model of murine γδTCR stoichiometry in which there are two CD3γε dimers for every TCRγδ heterodimer.
CCR5 deficiency increases risk of symptomatic West Nile virus infection
Authors: Glass William G. , McDermott David H. , Lim Jean K. , Lekhong Sudkamon , Yu Shuk Fong , Frank William A. , Pape John , Cheshier Ronald C. , Murphy Philip M.
Published: January 2006

West Nile virus (WNV) is a reemerging pathogen that causes fatal encephalitis in several species, including mouse and human. Recently, we showed that the chemokine receptor CCR5 is critical for survival of mice infected with WNV, acting at the level of leukocyte trafficking to the brain. To test whether this receptor is also protective in man, we determined the frequency of CCR5Δ32, a defective CCR5 allele found predominantly in Caucasians, in two independent cohorts of patients, one from Arizona and the other from Colorado, who had laboratory-confirmed, symptomatic WNV infection. The distribution of CCR5Δ32 in a control population of healthy United States Caucasian random blood donors was in Hardy-Weinberg equilibrium and CCR5Δ32 homozygotes represented 1.0% of the total group (n = 1,318). In contrast, CCR5Δ32 homozygotes represented 4.2% of Caucasians in the Arizona cohort (odds ratios [OR] = 4.4 [95% confidence interval [CI], 1.6–11.8], P = 0.0013) and 8.3% of Caucasians in the Colorado cohort (OR = 9.1 [95% CI, 3.4–24.8], P < 0.0001). CCR5Δ32 homozygosity was significantly associated with fatal outcome in the Arizona cohort (OR = 13.2 [95% CI, 1.9–89.9], P = 0.03). We conclude that CCR5 mediates resistance to symptomatic WNV infection. Because CCR5 is also the major HIV coreceptor, these findings have important implications for the safety of CCR5-blocking agents under development for HIV/AIDS.
Membrane-delimited Inhibition of Maxi-K Channel Activity by the Intermediate Conductance Ca2+-activated K Channel
Authors: Thompson Jill , Begenisich Ted
Published: January 2006

The complexity of mammalian physiology requires a diverse array of ion channel proteins. This diversity extends even to a single family of channels. For example, the family of Ca2+-activated K channels contains three structural subfamilies characterized by small, intermediate, and large single channel conductances. Many cells and tissues, including neurons, vascular smooth muscle, endothelial cells, macrophages, and salivary glands express more than a single class of these channels, raising questions about their specific physiological roles. We demonstrate here a novel interaction between two types of Ca2+-activated K channels: maxi-K channels, encoded by the KCa1.1 gene, and IK1 channels (KCa3.1). In both native parotid acinar cells and in a heterologous expression system, activation of IK1 channels inhibits maxi-K activity. This interaction was independent of the mode of activation of the IK1 channels: direct application of Ca2+, muscarinic receptor stimulation, or by direct chemical activation of the IK1 channels. The IK1-induced inhibition of maxi-K activity occurred in small, cell-free membrane patches and was due to a reduction in the maxi-K channel open probability and not to a change in the single channel current level. These data suggest that IK1 channels inhibit maxi-K channel activity via a direct, membrane-delimited interaction between the channel proteins. A quantitative analysis indicates that each maxi-K channel may be surrounded by four IK1 channels and will be inhibited if any one of these IK1 channels opens. This novel, regulated inhibition of maxi-K channels by activation of IK1 adds to the complexity of the properties of these Ca2+-activated K channels and likely contributes to the diversity of their functional roles.
Recent developments in the engineering of zinc finger proteins
Authors: Moore Michael , Ullman Christopher
Published: January 2006

Within the last 20 years, the understanding of the biology of the ‘classical’ or Cys2His2 zinc finger domain has progressed rapidly from the initial identification of the zinc finger as a repetitive zinc-binding motif in transcription factors to its use in biotechnology. The domain is the most abundant DNA-binding motif in the human genome and is a component of many key eukaryotic transcription factors involved in growth and development. Numerous structures now exist for this domain and its mode of action is known in a variety of zinc finger–DNA complexes. Application of this knowledge has led to the development of ‘designer’ transcription factors where zinc fingers have been engineered to bind desired DNA sequences. Recently, advances have been made in this field that potentially allow the targeting of any DNA site. Consideration of chromatin structure and the use of effector domains in these ‘designer’ transcription factors have made possible the regulation of a number of endogenous genes. These advances in the customised regulation of genes will be discussed in detail, as well as the potential to use these proteins in functional genomics and gene therapy applications.
Combining signals from spotted cDNA microarrays obtained at different scanning intensities
Authors: Piepho H. P. , Keller B. , Hoecker N. , Hochholdinger F.
Published: January 2006

Motivation: The analysis of spotted cDNA microarrays involves scanning of color signals from fluorescent dyes. A common problem is that a given scanning intensity is not usually optimal for all spotted cDNAs. Specifically, some spots may be at the saturation limit, resulting in poor separation of signals from different tissues or conditions. The problem may be addressed by multiple scans with varying scanning intensities. Multiple scanning intensities raise the question of how to combine different signals from the same spot, particularly when measurement error is not negligible.

Results: This paper suggests a non-linear latent regression model for this purpose. It corrects for biases caused by the saturation limit and efficiently combines data from multiple scans. Combining multiple scans also allows reduction of technical error particularly for cDNA spots with low signal. The procedure is exemplified using cDNA expression data from maize.

Availability: All methods were implemented using standard procedures available in the SAS/STAT module of the SAS System. Programming statements are available from the first author upon request.

Contact:  piepho@uni-hohenheim.de

Supplementary information: The supplementary data are available at Bioinformatics online.
CAM and the Phenomenology of Pain
Authors: Hankey Alex
Published: January 2006

Many CAM modalities afford relief from pain, each in its own way, or according to its own terminology. Comparison of different CAM modalities results in a simple phenomenology of pain centered around the idea that pain may be associated with blockages of the flow of energy in the system of nadis/acupuncture meridians.
Hippocampal CA1 kindling but not long-term potentiation disrupts spatial memory performance
Authors: Leung L. Stan , Shen Bixia
Published: January 2006

Long-term synaptic enhancement in the hippocampus has been suggested to cause deficits in spatial performance. Synaptic enhancement has been reported after hippocampal kindling that induced repeated electrographic seizures or afterdischarges (ADs) and after long-term potentiation (LTP) defined as synaptic enhancement without ADs. We studied whether repeated stimulations that gave LTP or ADs resulted in spatial performance deficits on the radial arm maze (RAM) and investigated the minimal number of ADs required for such deficits. Three experimental groups were run as follows: (1) 5 hippocampal ADs in 1 d (5-AD group), (2) 10 hippocampal ADs in 2 d (10-AD group), and (3) 12 θ-frequency primed-burst stimulations (PBSs) in 2 d in order to induce LTP without ADs (LTP group). Each experimental group was run together with a control group during the same time period. Rats were first trained in a spatial task on a radial arm maze with four of the eight arms baited, then given control or experimental treatment, and maze performance was tested in the first week (1-4 d) and fourth week (22-25 d) after treatment. Basal dendritic population excitatory postsynaptic potentials (pEPSPs) and medial perforant path (MPP)-evoked dentate gyrus population spike and polysynaptic CA1 excitation were recorded before and after experimental and control treatment. Spatial memory errors, in particular reference memory errors, were significantly higher in the 10-AD kindled group than any other group on the first and fourth week after treatment. Spatial memory errors were not significantly different in the 5-AD and LTP groups as compared with any control groups at any time. Basal dendritic pEPSP in CA1 was enhanced for about 1 wk after 12 PBSs, 10 ADs, or 5 ADs, while the dentate gyrus population spike and CA1 polysynaptic excitation evoked by MPP was increased for up to 4 wk after 10 ADs, but not 12 PBSs. Thus, distributed alteration of multiple synaptic transmission in the entorhinal-hippocampal circuit, but not LTP at the basal dendritic synapses in CA1, may disrupt spatial performance after 10 hippocampal ADs.
Isolation of Helicobacter pylori from the Intestinal Mucosa of Patients with Crohn's Disease
Authors: Oliveira Adriana Gonçalves , Rocha Gifone Aguiar , Rocha Andreia Maria Camargos , Sanna Maria das Graças Pimenta , Moura Sílvia Beleza , Dani Renato , Marinho Frederico Passos , Moreira Liano Sia , Ferrari Maria de Lourdes Abreu , Castro Lúcia Porto Fonseca , Queiroz Dulciene Maria Magalhães
Published: January 2006

Background:  Helicobacter species are associated with inflammatory bowel disease in rodents and in nonhuman primates. Therefore, we prospectively investigated the presence of Helicobacter species in the intestinal mucosa of patients with and without Crohn's disease by culture and polymerase chain reaction (PCR) assays.

Materials and Methods:  Mucosal fragments were obtained from the ileum, different colon regions, and rectum of 43 patients with Crohn's disease and of 74 patients without inflammatory bowel disease.

Results:  Helicobacter pylori strains, identified by 16S rRNA gene sequencing, were more frequently isolated and PCR‐detected in the intestinal mucosa of patients with ulcerative colitis‐like Crohn's disease than in intestinal mucosa of the control group. Otherwise, anti‐H. pylori immunoglobulin G levels were significantly lower in fibrostenosing and fistulating Crohn's disease subgroups. No other Helicobacter species were found in the intestinal mucosa of the patients.

Conclusions:  Although our results suggest an association between the presence of H. pylori in the intestine and ulcerative colitis‐like phenotype of Crohn's disease, H. pylori infection in the actual causality of Crohn's disease is still to be determined.
Efficacy of Moxifloxacin‐Based Triple Therapy as Second‐Line Treatment for Helicobacter pylori Infection
Authors: Cheon Jae Hee , Kim Nayoung , Lee Dong Ho , Kim Jung Mogg , Kim Joo Sung , Jung Hyun Chae , Song In Sung
Published: January 2006

Background and Aim:  Metronidazole and tetracycline‐based second‐line quadruple therapy, widely used for Helicobacter pylori infection, often ends up in failure due to antibiotic resistance and poor compliance in Korea. Our aim is to evaluate the efficacy and tolerability of moxifloxacin‐based triple therapy as an alternative second‐line treatment for H. pylori infection.

Methods:  The subjects consisted of 85 patients infected with H. pylori, in whom initial proton pump inhibitor triple therapy had failed. They were randomized to receive the following 7‐day therapy: 1, moxifloxacin 400 mg q.d., esomeprazole 20 mg b.i.d., and amoxicillin 1 g b.i.d.; and 2, esomeprazole 40 mg b.i.d., tripotassium dicitrate bismuthate 300 mg q.i.d., metronidazole 500 mg t.i.d., and tetracycline 500 mg q.i.d. Eradication rates, drug compliance, and side‐effect rates of each group were evaluated.

Results:  The eradication rates were 75.6 and 83.8% with moxifloxacin triple therapy, and 54.5 and 72.7% with quadruple therapy by intention‐to‐treat (p = .042) and per‐protocol analyses (p = .260), respectively. Moxifloxacin triple therapy was significantly superior to quadruple therapy in terms of side‐effect rates (p = .039). Compliance for therapy, i.e., the percentage of tablets taken (> 85%), was 90.2 and 75.0%, numerically higher in moxifloxacin triple therapy group than in quadruple therapy group, but without statistical difference (p = .065).

Conclusions:  Moxifloxacin‐based triple therapy showed high eradication rates with few side effects and good drug compliance, suggesting this regimen could be a safe and effective option as second‐line therapy for H. pylori infection in Korea.
7‐Day Triple Therapy of Helicobacter pylori Infection with Levofloxacin, Amoxicillin, and High‐Dose Esomeprazole in Patients with Known Antimicrobial Sensitivity
Authors: Antos David , Schneider‐Brachert Wulf , Bästlein Elke , Hänel Christine , Haferland Christian , Buchner Michael , Meier Eberhard , Trump Friedrich , Stolte Manfred , Lehn Norbert , Bayerdörffer Ekkehard
Published: January 2006

Background and Aims:  Failed primary anti‐Helicobacter pylori therapy results in a high rate of antimicrobial resistance. This necessitates a search for new regimens to cure H. pylori infection. The aim of this study was to evaluate the efficacy and tolerability of a new levofloxacin‐containing 7‐day triple therapy and to compare it with that of standard French triple therapy in patients with known H. pylori susceptibility to MET (metronidazole) and CLA (clarithromycin).

Patients and Methods:  Sixty‐one patients with documented antibiotic sensitivity (E‐test) and an indication for anti‐H. pylori treatment based on the Maastricht Consensus 2/2000 guidelines were randomized to receive either esomeprazole 2 × 40 mg, levofloxacin 2 × 500 mg, and amoxicillin 2 × 1 g for 7 days (ELA, n = 30), or esomeprazole 2 × 20 mg, clarithromycin 2 × 500 mg, and amoxicillin 2 × 1 g for 7 days (ECA, n = 31). A cure check was performed 4–6 weeks after conclusion of therapy.

Results:  Sixty‐one patients were randomized to the two treatment groups. Twenty‐eight of 30 patients of the ELA group were available for per‐protocol (PP) analysis, of whom 26 (92.9% CI: 76–99%; intention‐to‐treat [ITT] analysis 86.7% CI: 68–96%) became H. pylori negative compared with 26 of the 31 patients of the ECA group (83.9%, CI: 66–93% both PP and ITT analyses). Five patients of the ELA group showed CLA resistance, three of whom also showed MET resistance, and all five were treated successfully. Two patients with levofloxacin‐resistant strains, one in each group, were cured. Both regimens were generally well tolerated with minor adverse events being seen in 15 patients (51.7%) of the ELA group and in 13 (40.6%) of the ECA group. None of the patients discontinued treatment prematurely due to adverse events.

Conclusion:  The data of this pilot study suggest a better than 80% efficacy of the new 7‐day levofloxacin triple therapy, which is within the range of the French triple therapy in patients with MET‐ and CLA‐susceptible strains. The data suggest that the new levofloxacin triple therapy may also be an option in patients with MET‐ and CLA‐resistant H. pylori strains.
Helicobacter pylori Infection, but not Low‐Dose Aspirin, Results in a Local Reduction of the Secretory Leukocyte Protease Inhibitor in Gastroduodenal Mucosa
Authors: Wex Thomas , Ye Siying , Treiber Gerhard , Vieth Michael , Roessner Albert , Malfertheiner Peter
Published: January 2006

Background:  The secretory leukocyte protease inhibitor (SLPI) represents a multifunctional protein with mucosa‐protective features. Helicobacter pylori and the usage of low‐dose aspirin are two independent risk factors for the development of gastrointestinal diseases. Therefore, the effect of low‐dose aspirin on gastrointestinal SLPI expression was analyzed in the context of H. pylori infection.

Material and Methods:  The study included 20 volunteers (H. pylori positive and negative: n = 10) who received 2 × 50 mg aspirin/day for 7 days. H. pylori‐positive subjects underwent eradication therapy and repeated the protocol. Gastroduodenoscopy was performed at day 0, 1, 3, and 7, and biopsies were obtained each from antrum, corpus, and duodenal bulb. SLPI expression was determined by quantitative reverse transcription‐polymerase chain reaction (RT‐PCR) and enzyme‐linked immunosorbent assay (ELISA).

Results:  A reduction of antral SLPI levels, ranging between 582 (day 0) and 941 pg/10 µg protein (day 7), was determined in H. pylori‐positive compared to H. pylori‐negative and ‐eradicated subjects (1600–2050 pg/10 µg protein, ANOVA: p = .001–.045). No differences concerning aspirin were observed within the groups. SLPI levels in corpus and duodenal mucosa were neither affected by H. pylori nor low‐dose aspirin. There was an inverse correlation between SLPI and H. pylori‐induced inflammation (activity: r = −0.575, −0.69 to −0.43, p < .0001; chronicity: r = −0.54, −0.66 to −0.39, p < .0001) in antral mucosa only, whereas other locations as well as the usage of low‐dose aspirin did not show an association between SLPI and inflammation.

Conclusions:  H. pylori infection, but not the usage of low‐dose aspirin, has a role in the down‐regulation of antral SLPI levels.
A clinically relevant contact allergy to methyldibromo glutaronitrile at 1% (0.32 mg/cm2) detected by a patch test
Authors: Bruze Magnus , Gruvberger Birgitta , Zimerson Erik
Published: January 2006

Recently, the preservative methyldibromo glutaronitrile (MDBGN) at 0.5% w/w in petrolatum was included in the European standard patch test series based on the studies on chemical stability and consideration of rates of contact allergy, doubtful and irritant reactions as well as information on clinical relevance represented by results of a repeated open application test (ROAT) and patch test concentrations required to diagnose allergic contact dermatitis from MDBGN in individual cases. In this report, a case with a clinically relevant contact allergy to MDBGN, which on the mandatory reading occasion on D3 only was traced by a patch test with MDBGN at 1.0% (0.32 mg/cm2), is presented. The patient suffered from a chronic hand dermatitis, and when the patient stopped using a liquid soap containing MDBGN, the hand dermatitis substantially improved. A ROAT performed in a blinded and controlled way with applications twice daily on the hands with 2 moisturizers with and without MDBGN resulted in a deterioration of the hand dermatitis on the hand to which the MDBGN‐preserved moisturizer had been applied.
Eczema‐like plaques secondary to enoxaparin
Authors: White J. M. L. , Munn S. E. , Seet J. ‐E. , Adams N. , Clement M.
Published: January 2006

Low‐molecular‐weight heparins are used extensively in acute medicine. They are generally well tolerated but may cause a rare, eczema‐like type IV hypersensitivity reaction. We report 3 cases of this eruption and speculate that it may be significantly under‐reported due to misidentifying the causal drug, which may have serious consequences. We discuss treatment alternatives such as fondaparinux sodium, which may rarely cross‐react.
Allergenicity and cross‐reactivity of naphthenic acid and its metallic salts in experimental animals
Authors: Yamano Tetsuo , Shimizu Mitsuru , Noda Tsutomu
Published: January 2006

The allergenicity and the cross‐reactivity of naphthenic acid (NA) and its metallic salts were evaluated in experimental animals. In the guinea pig maximization test, sensitizing skin reactions were observed with cobalt naphthenate (CoN), zinc naphthenate (ZnN) and NA, but not with copper naphthenate, with CoN being the most potent sensitizer. Animals sensitized with 1 naphthenic compound cross‐reacted to the other 3 as well. Furthermore, animals in the CoN‐sensitized group reacted to the relevant metallic salt cobalt chloride (CoCl2). A dose–response study using the CoN‐sensitized group showed that the concentration of CoCl2 required to elicit a skin reaction of similar extent in comparison with CoN was more than 10 times higher, when skin‐reaction scores were compared on the basis of cobalt content. In the local lymph node assay, significant increases in stimulation index values without skin irritation were observed with CoN and ZnN, where the former was more potent than the latter. Although CoN is a reported skin sensitizer, this study showed that skin allergenicity of naphthenic compounds is not restricted solely to CoN. In addition, the results suggest the main antigenic determinant of naphthenic compounds to be the structure of NA, even though metal moieties modulate their allergenicity.
Can an imidazolidinyl urea‐preserved corticosteroid cream be safely used in individuals hypersensitive to formaldehyde?
Authors: Isaksson Marléne , Gruvberger Birgitta , Goon Anthony T.‐J. , Bruze Magnus
Published: January 2006

A topical corticosteroid preparation on the Swedish market, Flutivate® cream, contains a fairly high concentration of formaldehyde (FA). In this study, we have investigated the clinical relevance of contact allergy to FA when treating an allergic eczema with Flutivate® cream, containing an FA‐releasing preservative. In a randomized, double‐blind study, 7 patients hypersensitive to both FA and nickel repeatedly applied Flutivate® cream containing FA or Betnovate® cream not containing FA to areas of experimentally induced nickel dermatitis. 17 controls allergic to nickel, but not FA, went through the same procedure. In 29 per cent of the FA‐allergic individuals, the experimental dermatitis healed when treated with Flutivate® cream compared with 71 per cent of the controls (P = 0.04). The conclusion to draw from this study is that an individual hypersensitive to FA should not use the corticosteroid preparation Flutivate® cream on dermatitis skin.
High‐fat petrolatum‐based moisturizers and prevention of work‐related skin problems in wet‐work occupations
Authors: Mygind Karen , Sell Lea , Flyvholm Mari‐Ann , Jepsen Karen Frydendall
Published: January 2006

The study presented is a randomized, controlled intervention study with the purpose of implementing an evidence‐based skin disease prevention programme. The hypothesis explored in this article is whether a high‐fat petrolatum‐based moisturizer can be an alternative to protective gloves in wet‐work occupations. The study population was all gut cleaners in Danish swine slaughterhouses, and data were collected by telephone interviews using a standardized questionnaire – The Nordic Occupational Skin Questionnaire (NOSQ‐2002). At baseline, 644 (88%) gut cleaners responded and at 1‐year follow‐up 622 (72%). 135 gut cleaners in the intervention and 277 in the comparison group responded at both telephone interviews. In the intervention group, the eczema frequency was reduced significantly. Detailed analyses revealed that protective gloves are the overall most effective protective means and did not indicate that a high‐fat moisturizer could be an alternative. Furthermore, the most extensive improvements could not be explained by combinations of protective behaviour but was found among those who had received information on, and was having discussions on prevention of skin problems. This only applied to the intervention group. A continuous focus on prevention of skin problems with information and discussions on the shop floor therefore seemed to be most important for reducing skin problems.
An in vivo model to evaluate the efficacy of barrier creams on the level of skin penetration of chemicals
Authors: Teichmann Alexa , Jacobi Ute , Waibler Evguenia , Sterry Wolfram , Lademann Jürgen
Published: January 2006

The reservoir function and the barrier function are important properties of the skin. The reservoir function is dependent on the barrier function which, however, needs support by protective measures, in particular under working conditions. Barrier creams represent a possibility to protect the skin.

In the present study, a method was developed to investigate the effectiveness of reservoir closure by different formulations. Patent Blue V in water was used as a model penetrant. Its penetration, with and without barrier cream treatment, was analyzed by tape stripping in combination with UV/VIS spectroscopic measurements.

The investigations showed that the stratum corneum represents a reservoir for topically applied Patent Blue V in water. Furthermore, the barrier investigations showed that vaseline and bees wax form a 100% barrier on the skin surface. The third barrier cream, containing waxes and surfactant, only partially showed a protective effect against the penetration of Patent Blue V in water. Strong interindividual differences were observed for this barrier product.

In conclusion, it was assumed that the application of barrier creams cannot replace other protective measures and should be maximally used to inhibit low‐grade irritants or in combination with other protectants or in body areas where other protective measures are not applicable.
Two cases of thiopurine methyltransferase (TPMT) deficiency – a lucky save and a near miss with azathioprine
Authors: Gardiner Sharon J. , Gearry Richard B. , Barclay Murray L. , Begg Evan J.
Published: January 2006

Background

The association between thiopurine methyltransferase (TPMT) deficiency and myelosuppression with azathioprine is well recognized. Two cases are presented that illustrate the very different outcomes that may occur with azathioprine in patients with TPMT deficiency, which affects 0.3–0.6% of caucasians.

Case 1

The first patient’s TPMT deficiency was identified following hospitalization for pancytopenia attributed to azathioprine.

Case 2

The second patient was identified as deficient early in treatment and myelosuppression was avoided by treating with a greatly decreased dose (25 mg per week).

Conclusions

Testing for TPMT ideally should be performed in every patient commencing a thiopurine drug.
Thein vitrometabolism of irinotecan (CPT‐11) by carboxylesterase and β‐glucuronidase in human colorectal tumours
Authors: Tobin Peter , Clarke Stephen , Seale J Paul , Lee Soon , Solomon Michael , Aulds Sally , Crawford Michael , Gallagher James , Eyers Tony , Rivory Laurent
Published: January 2006

Aims

Irinotecan (CPT‐11) is a prodrug that is used to treat metastatic colorectal cancer. It is activated to the topoisomerase poison SN‐38 by carboxylesterases. SN‐38 is metabolized to its inactive glucuronide, SN‐38 glucuronide. The aim of this study was to determine, the reactivation of SN‐38 from SN‐38 glucuronide by β‐glucuronidase may represent a significant pathway of SN‐38 formation.

Methods

The production of SN‐38 from irinotecan and SN‐38 glucuronide (2.4, 9.6 and 19.2 µm) was measured in homogenates of human colorectal tumour, and matched normal colon mucosa from 21 patients).

Results

The rate of conversion of irinotecan (9.6 µm) was lower in tumour tissue than matched normal colon mucosa samples (0.30 ± 0.14 pmol min−1 mg−1protein and 0.77 ± 0.59 pmol min−1 mg−1protein, respectively;P < 0.005). In contrast, no significant difference was observed in β‐glucuronidase activity between tumour  and matched normal colon samples (4.56 ± 6.9 pmol min−1 mg−1protein and 3.62 ± 2.95 pmol min−1 mg−1protein, respectively, using 9.6 µmSN‐38 glucuronide;P > 0.05). β‐Glucuronidase activity in tumour correlated to that observed in matched normal tissue (r2 > 0.23,P < 0.05), whereas this was not the case for carboxylesterase activity. At equal concentrations of irinotecan and SN‐38 glucuronide, the rate of β‐glucuronidase‐mediated SN‐38 production was higher than that formed from irinotecan in both tumour and normal tissue (P < 0.05). However, at concentrations that reflect the relative plasma concentrations observed in patients, the rate of SN‐38 production via these two pathways was comparable.

Conclusions

Tumour β‐glucuronidase may play a significant role in the exposure of tumours to SN‐38in vivo.
Comparative Analysis of Immunoreactive Cells for Androgen Receptors and Oestrogen Receptor α in Copulating and Non‐Copulating Male Rats
Authors: Portillo W. , Díaz N. F. , Cabrera E. Antonio , Fernández‐Guasti A. , Paredes R. G.
Published: January 2006

In some species, including gerbils, guinea pigs, mice, rams and rats, some apparently normal males fail to mate. These kinds of animals have been named ‘noncopulating (NC)’. The cause of this behavioural deficit is unknown. The present study aimed to determine whether NC male rats have alterations in the amount of androgen (AR) and oestrogen receptor α (ERα) in a neuronal circuit important for the control of male sexual behaviour; the vomeronasal projection pathway. We evaluated the number of AR and ERα immunoreactive (AR‐IR and ERα‐IR) cells in the accessory olfactory bulb (AOB), the bed nucleus of the stria terminalis (BNST), the anterior‐dorsal medial amygdala (MeAD), the posterior dorsal amygdala (MePD) and the medial preoptic area (MPOA). The results demonstrate that the number of AR‐IR cells in NC males was significantly higher compared to copulating (C) males in the MePD, but no significant differences were found in any of the other structures analysed. ERα‐IR cells were more abundant in NC than in C males in the MeAD and the MePD. However, in the MPOA the number of ERα‐IR cells was significantly reduced in NC males. No significant differences were found in the AOB or in the BNST. A similar pattern of results was observed when regions within these structures that are activated by Fos expression, on mating or exposure to sexually relevant cues were analysed. The differences in the number of AR and ER in particular brain areas could be associated with alterations in sexual behaviour as well as partner and olfactory preference for receptive females seen in NC male rats.
Molecular characterization of the capsule locus from non‐typeableStaphylococcus aureus
Authors: Cocchiaro Jordan L. , Gomez Marisa I. , Risley Allison , Solinga Robert , Sordelli Daniel O. , Lee Jean C.
Published: January 2006

MostStaphylococcus aureusexpress a serotype 5 or 8 capsular polysaccharide (CP). However, 20–25% of human isolates and up to 86% of bovine strains ofS. aureusare non‐typeable (NT), i.e. non‐reactive with antibodies to CP types 1, 2, 5 or 8. A vaccine that targets theS. aureusCP would not protect against NT strains. The aim of this study was to characterize NTS. aureusisolates at the molecular level to explain their lack of type 5 or 8 capsule production. Thecap5(8)locus was present in all 22 NT clinical isolates from humans, eight of 21 bovine isolates, and in all eight sequenced strains. NT strains positive for thecap5(8)transcript had mutations within essential capsule genes and could be complementedin trans.S. aureusstrains with reducedcap5(8)transcript had mutations within thecap5Apromoter, decreased RNAIII levels,or a truncatedarlRgene product. More than one mutation was identified in several isolates. Thecap5(8)locus was replaced by IS257in 13 of 21 NT bovine isolates ofS. aureus. Lack of capsule expression in NTS. aureuscan be explained by multiple mechanisms, and the data argue against the existence of capsule serotypes other than 1, 2, 5 and 8.