bluuebunny/crossref_metadata_2025_split huggingface dataset:
Protection from Anthrax Toxin-Mediated Killing of Macrophages by the Combined Effects of Furin Inhibitors and Chloroquine
Authors: Komiyama Tomoko , Swanson Joel A. , Fuller Robert S. 
Published: August 2005

ABSTRACT
Cell surface proteolytic processing of anthrax protective antigen by furin or other furin-related proteases is required for its oligomerization, endocytosis, and function as a translocon for anthrax lethal and edema factors. Countering toxin lethality is essential to developing effective chemotherapies for anthrax infections that have proceeded beyond the stage at which antibiotics are effective. The primary target for toxin is the macrophage, which can be killed by lethal factor via both necrotic and apoptotic pathways. Here we show that three high-affinity inhibitors of furin efficiently blocked killing of murine J774A.1 macrophages by recombinant protective antigen plus lethal factor: RRD-eglin and RRDG-eglin, developed by engineering the protein protease inhibitor eglin c, and the peptide boronic acid inhibitor acetyl-Arg-Glu-Lys-boroArg pinanediol. Inhibition of killing was dose dependent and correlated with prevention of protective antigen processing. Previous studies have shown that weak bases, such as chloroquine, which neutralize acidic compartments, also interfere with toxin-dependent killing. Here we show that combining furin inhibitors and chloroquine strongly augments the inhibition of toxin-dependent killing, suggesting that combined use of antifurin drugs and chloroquine might provide enhanced therapeutic benefits. Reversible furin inhibitors protected against anthrax toxin killing for at least 5 h, but by 8 h, toxin-dependent killing resumed even though furin inhibitors were still active. An irreversible chloromethylketone inhibitor did not exhibit this loss of protection.
Interleukin-8-Derived Peptide Has Antibacterial Activity
Authors: Björstad Åse , Fu Huamei , Karlsson Anna , Dahlgren Claes , Bylund Johan 
Published: August 2005

ABSTRACT

Chemokines are inflammatory mediators with effects on diverse processes associated with the immune response. Some of the proteins belonging to the CXC chemokine subfamily, one of four groups in the family, possess inherent antibacterial activity against a wide range of bacteria. The CXC chemokine interleukin-8 (IL-8) has not been ascribed any direct antibacterial activity, but the fact that several of the amino acids in the carboxy-terminal part of the protein are identical or similar to those in a bactericidal cecropin-like peptide [Hp(2-20)] from
Helicobacter pylori
suggests that processing of the cytokine might generate peptide fragments with antibacterial properties. Synthetic peptides representing the carboxy-terminal part of IL-8 were investigated for antibacterial activities. These fragments possessed an antibacterial activity absent in the full-length IL-8. The antibacterial effects were reduced at increasing salt concentrations whereas the activity was increased when the pH was lowered. The IL-8-derived peptide shared structural similarity with and was also functionally additive to the Hp(2-20) peptide. The IL-8-derived peptide lacked the proinflammatory effects of the full-length protein. We also showed that acid hydrolysis of IL-8 generated a major peptide fragment corresponding to the antibacterial carboxyl terminus of the protein. The results presented are of special interest when put in the context of the suggested importance of antimicrobial peptides for microbial colonization of the gastric mucosa.
Oxazolidinones Inhibit Cellular Proliferation via Inhibition of Mitochondrial Protein Synthesis
Authors: Nagiec Eva E. , Wu Luping , Swaney Steve M. , Chosay John G. , Ross Daniel E. , Brieland Joan K. , Leach Karen L. 
Published: August 2005

ABSTRACT

The oxazolidinones are a relatively new structural class of antibacterial agents that act by inhibiting bacterial protein synthesis. The oxazolidinones inhibit mitochondrial protein synthesis, as shown by [
35
S]methionine incorporation into intact rat heart mitochondria. Treatment of K562 human erythroleukemia cells with the oxazolidinone eperezolid resulted in a time- and concentration-dependent inhibition of cell proliferation. The cells remained viable, but an increase in doubling time was observed with eperezolid treatment. Inhibition was reversible, since washing and refeeding of cells in the absence of compound resulted in a resumption of growth. The growth-inhibitory effect of the oxazolidinones did not appear to be cell type specific, and inhibition of CHO and HEK cells also was demonstrated. Treatment of cells resulted in a decrease in mitochondrial cytochrome oxidase subunit I levels, consistent with an inhibition of mitochondrial protein synthesis. Eperezolid caused no growth inhibition of rho zero (ρ
0
) cells, which contain no mitochondrial DNA; however, the growth of the parent 143B cells was inhibited. These results provide a direct demonstration that the inhibitory effect of eperezolid in mammalian cells is the result of mitochondrial protein synthesis inhibition.
Tigecycline MIC Testing by Broth Dilution Requires Use of Fresh Medium or Addition of the Biocatalytic Oxygen-Reducing Reagent Oxyrase To Standardize the Test Method
Authors: Bradford Patricia A. , Petersen Peter J. , Young Mairead , Jones C. Hal , Tischler Mark , O'Connell John 
Published: August 2005

ABSTRACT

Tigecycline is a broad-spectrum glycylcycline antibiotic with activity against not only susceptible gram-positive and gram-negative pathogens but also strains that are resistant to many other antibiotics. In the process of determining quality control (QC) limits for the American Type Culture Collection reference strains for tigecycline, a number of inconsistencies in MICs were encountered which appeared to be related to the age of the Mueller-Hinton broth (MHB) medium used in the MIC testing. The objective of this study was to determine the cause of the discrepant MIC results between fresh and aged MHB. The MICs of tigecycline were determined in MHB that was either prepared fresh (<12 h old), prepared and stored at 4°C, stored at room temperature, stored anaerobically, or supplemented with the biocatalytic oxygen-reducing reagent Oxyrase. When tested in fresh media, tigecycline was 2 to 3 dilutions more active against the CLSI-recommended QC strains compared to aged media (MICs of 0.03 to 0.25 and 0.12 to 0.5 μg/ml, respectively). Media aged under anaerobic conditions prior to testing or supplemented with Oxyrase resulted in MICs similar to those obtained in fresh medium (MICs of 0.03 to 0.12 and 0.03 to 0.25 μg/ml, respectively). Time-kill kinetics demonstrated a >3 log
10
difference in viable growth when tigecycline was tested in fresh or Oxyrase-supplemented MHB compared to aged MHB. High-pressure liquid chromatography analysis revealed the accumulation of an early peak (oxidative by-product of tigecycline) to be 3.5% in fresh media and 25.1% in aged media after 24 h and that addition of Oxyrase prevented the accumulation of this oxidized by-product. These results suggested that the activity of tigecycline was affected by the amount of dissolved oxygen in the media. The use of fresh MHB or supplementation with Oxyrase resulted in a more standardized test method for performing MIC tests with tigecycline.
Targeting of the Virulence Factor Acetohydroxyacid Synthase by Sulfonylureas Results in Inhibition of Intramacrophagic Multiplication of
Brucella suis
Authors: Boigegrain Rose-Anne , Liautard Jean-Pierre , Köhler Stephan 
Published: August 2005

ABSTRACT

The acetohydroxyacid synthase (AHAS) of
Brucella suis
can be effectively targeted by the sulfonylureas chlorimuron ethyl and metsulfuron methyl. Growth in minimal medium was inhibited, and multiplication in human macrophages was totally abolished with 100 μM of sulfonylureas. Metsulfuron methyl-resistant mutants showed reduced viability in macrophages and reduced AHAS activity.
In Vitro Activity and Killing Effect of Uperin 3.6 against Gram-Positive Cocci Isolated from Immunocompromised Patients
Authors: Giacometti Andrea , Cirioni Oscar , Kamysz Wojciech , Silvestri Carmela , Licci Alberto , D'Amato Giuseppina , Nadolski Piotr , Riva Alessandra , Lukasiak Jerzy , Scalise Giorgio 
Published: August 2005

ABSTRACT

The in vitro activity of uperin 3.6, alone or combined with six antibiotics, against gram-positive cocci, including
Rhodococcus equi
, methicillin-resistant staphylococci, and vancomycin-resistant enterococci, was investigated. All isolates were
inhibited at concentrations of 1 to 16 mg/liter. Synergy was demonstrated when uperin 3.6 was combined with clarithromycin and
doxycycline.
The
vanB2
Gene Cluster of the Majority of Vancomycin-Resistant
Enterococcus faecium
Isolates from Taiwan Is Associated with the
pbp5
Gene and Is Carried by Tn
5382
Containing a Novel Insertion Sequence
Authors: Lu Jang-Jih , Chang Tein-Yao , Perng Cherng-Lih , Lee Shih-Yi 
Published: August 2005

ABSTRACT

Thirty-two
vanB2 Enterococcus faecium
isolates were found to harbor Tn
5382
. Twenty-four isolates had a 1,419-bp sequence inserted within the open reading frame (ORF) C of Tn
5382
. This 1,419-bp sequence contained a 638-bp ORF with a 72% amino acid sequence homology with the transposase gene of IS
150
. Thirty isolates had the
pbp5
gene linked to Tn
5382
.
Chromosome- and Plasmid-Encoded β-Lactamases in
Capnocytophaga
spp
Authors: Handal Trude , Giraud-Morin Chantal , Caugant Dominique A. , Madinier Isabelle , Olsen Ingar , Fosse Thierry 
Published: August 2005

ABSTRACT

Chromosome- and plasmid-encoded CfxA2 and CfxA3 β-lactamases were detected in
Capnocytophaga
spp. from oral sources in France, Norway, and the United States. Unidentified chromosome-encoded β-lactamases were present in
Capnocytophaga sputigena
. Nucleotide sequence analysis of the CfxA3-encoding plasmid from
C. ochracea
revealed an unreported insertion sequence (IS
Coc1
) upstream of the
cfxA
gene.
Use of Pharmacokinetic-Pharmacodynamic Target Attainment Analyses To Support Phase 2 and 3 Dosing Strategies for Doripenem
Authors: Bhavnani Sujata M. , Hammel Jeffrey P. , Cirincione Brenda B. , Wikler Matthew A. , Ambrose Paul G. 
Published: August 2005

ABSTRACT
A doripenem population pharmacokinetic model and Monte Carlo simulations were utilized for dose regimen decision support for future clinical development. Simulation results predict that 500 mg of doripenem administered over 1 h every 8 h would be effective against bacterial strains with MICs less than 2 μg/ml and that less susceptible strains could be treated with prolonged infusions.
Cloning and Characterization of a Novel Trimethoprim-Resistant Dihydrofolate Reductase from a Nosocomial Isolate of
Staphylococcus aureus
CM.S2 (IMCJ1454)
Authors: Sekiguchi Jun-ichiro , Tharavichitkul Prasit , Miyoshi-Akiyama Tohru , Chupia Vena , Fujino Tomoko , Araake Minako , Irie Atsushi , Morita Koji , Kuratsuji Tadatoshi , Kirikae Teruo 
Published: August 2005

ABSTRACT

A novel gene,
dfrG
, encoding a trimethoprim (TMP)-resistant dihydrofolate reductase (DHFR, designated S3DHFR) was cloned from a clinical isolate of methicillin-resistant
Staphylococcus aureus. Escherichia coli
expressing
dfrG
was highly resistant to TMP. Recombinant S3DHFR exhibited DHFR activity that was not inhibited by TMP.
In Vitro Antifungal Susceptibilities ofSporothrix schenckiiin Two Growth Phases
Authors: Trilles Luciana , Fernández-Torres Belkys , dos Santos Lazéra Márcia , Wanke Bodo , de Oliveira Schubach Armando , de Almeida Paes Rodrigo , Inza Isabel , Guarro Josep 
Published: August 2005

ABSTRACTWe have determined the antifungal susceptibilities of 34 clinical isolates of the dimorphic fungusSporothrix schenckiito 11 drugs using a microdilution method. In general, the type of growth phase (mycelial or yeast) and the temperature of incubation (30 or 35°C) exerted a significant influence on the MICs.
Upregulation of tissue kallikrein, kinin B1receptor, and kinin B2receptor in mast and giant cells infiltrating oesophageal squamous cell carcinoma
Authors: Dlamini Z , Bhoola K D 
Published: August 2005

Background:The mitogenic kinin peptides formed by the serine protease, tissue kallikrein (TK1), stimulate the proliferation of tumour cells and, by increasing vascular permeability, enhance metastasis. Oesophageal mucosal epithelial cells are derived from the epithelial cell germ layer, which expresses the kallikrein–kinin cascade.Aim:To determine the cellular distribution of active TK1, prokallikrein, and the kinin B1and B2receptors in oesophageal carcinoma by immunocytochemistry and in situ hybridisation (ISH).Methods:Fifty oesophageal specimens (33 biopsies and 17 resections) and 10 control specimens adjacent to tumour or normal oesophageal biopsies were studied. Specific antibodies were used to determine the cellular localisation of TK1, prokallikrein, and the kinin B1and B2receptors in normal and oesophageal specimens by standard immunohistochemical techniques. The intensity of immunolabelling was quantified by image analysis. Antisense probes for TK1 and the kinin B1and B2receptors were also used to localise mRNA.Results:TK1 (active and prokallikrein) was expressed in the mucosa of normal and tumour oesophageal epithelium. In general, expression was highest in activated mast cells, followed by giant tumour cells. Immunolabelling results were confirmed by ISH experiments.Conclusions:This is the first demonstration that TK1 and kinin B1and B2receptors are expressed in oesophageal carcinoma. Because TK1 released from tumour cells enzymatically generates mitogenic kinins from its endogenous substrate, kininogen, it is possible that third generation kinin receptor antagonists, which have been shown to be cytotoxic to cancer cells, may be useful therapeutic agents in this disease.
Differences between serum and plasma for intact parathyroid hormone measurement in patients with chronic renal failure in routine clinical practice
Authors: Twomey P J , Whitlock T , Pledger D R 
Published: August 2005

Background:Parathyroid hormone (PTH) is important in the evaluation of patients with calcium metabolism disorders and/or chronic renal disease.Aims:To assess the differences between serum and plasma PTH measurements using the Advia Centaur.Methods:Twenty six paired serum and edetate samples from patients with chronic renal failure were analysed using the Advia Centaur.Results:The EDTA results ranged from 2.3 to 76.1 pmol/litre and the Deming regression equation was: serum  =  0.8927 EDTA − 0.447. The percentage difference plot had a mean difference of 13.8% (95% confidence interval, 2.2% to 25.4%; significant). The available time to separation and freezing ranged from 10 to 231 (median, 85) minutes. The correlation coefficient for the percentage difference against the time to separation and the percentage difference against the mean PTH concentration were −0.13 and −0.07, respectively.Conclusions:These results go beyond the previous controlled research conditions by showing that such differences between serum and edentate plasma exist in routine clinical practice. They also show that intra-individual PTH differences as large as 25.0% can exist on the same day between serum and edetate plasma. This may partly explain some of the variability of PTH concentrations found in some patients with chronic renal failure.
High frequency of germinal centre derivation in diffuse large B cell lymphoma from Asian patients
Authors: Shia A K H , Gan G-G , Jairaman S , Peh S-C 
Published: August 2005

Background:Recent reports have divided diffuse large B cell lymphoma (DLBCL) into germinal centre B cell-like and activated B cell-like subgroups with implicated differences in prognosis.Aims:To delineate the germinal centre B cell derivation group from an Asian series of DLBCLs.Methods:Fifty four cases were analysed by polymerase chain reaction to detect the t(14;18) translocation and immunohistochemistry for BCL2, CD10, BCL6, and E2F1 expression.Results:Eighteen of 54 cases hadbcl2gene rearrangement, 36 of 52 expressed BCL2, 29 of 52 expressed BCL6, 20 of 53 expressed CD10, and 18 of 53 expressed E2F1. There was a significant association betweenbcl2gene rearrangement and the expression of both BCL2 and CD10. Using the minimally acceptable criteria of t(14;18) rearrangement and/or CD10 expression, 26 of 54 cases were probably germinal centre derived, in agreement with other reports. A higher proportion of cases had t(14;18) translocation, suggesting that they may be derived from transformed follicular lymphomas. E2F1 positivity did not correlate with the known germinal centre markers, even though it has recently been suggested that it may be a new GC marker.Conclusions:It may be possible to stratify patients for treatment using markers for specific lineages of B cell differentiation.
CD56: a useful tool for the diagnosis of small cell lung carcinomas on biopsies with extensive crush artefact
Authors: Kontogianni K , Nicholson A G , Butcher D , Sheppard M N 
Published: August 2005

Background/Aims:The diagnosis of small cell lung carcinoma (SCLC) on bronchial biopsy is often problematical as a result of intense crush artefact. Several antibodies are now available to help in the diagnosis of SCLC and their value was assessed in this clinical situation.Methods/Results:Twenty cases of SCLC and 10 control cases (one non-Hodgkin lymphoma, three non-small cell carcinomas, one follicular reactive hyperplasia, and five chronic non-specific inflammations) with extensive crush artefact were stained using antibodies to CD56, MNF116, thyroid transcription factor 1 (TTF-1), and CD45. All SCLCs showed strong positive staining for CD56 in 75–100% of recognisable tumour cells, even in areas where there was extensive crush artefact. Eighteen of 20 cases were positive for TTF-1 and 16 of 20 were positive for MNF116 in the tumour cells, but both of these antibodies showed little or no staining in areas of crush artefact. Control cases comprising lymphoid cells were positive for CD45 in areas of crush artefact, but all cases of SCLC were negative.Conclusion:CD56, along with markers for cytokeratins—TTF-1, and CD45—are useful in the diagnosis of SCLC in biopsies with extensive crush artefact and can help confirm the diagnosis in cases where features are equivocal.
Increased E2F-1 expression via tumour cell proliferation and decreased apoptosis are correlated with adverse prognosis in patients with squamous cell carcinoma of the oesophagus
Authors: Yamazaki K , Hasegawa M , Ohoka I , Hanami K , Asoh A , Nagao T , Sugano I , Ishida Y 
Published: August 2005

Background:The retinoblastoma (Rb) pathway, which governs cell cycle progression, is frequently genetically altered in cancer, causing deregulated expression of the E2F-1 transcription factor, which promotes DNA synthesis and cell cycle progression. Recent studies show that E2F-1 also participates in apoptosis induction in a p53 dependent or independent manner. Despite its crucial role and paradoxical effects on cell turnover, the function of E2F-1 in human cancer is unclear.Aims:To evaluate E2F-1 expression using immunohistochemistry in 43 surgically resected oesophageal squamous cell carcinoma (OSCC) specimens.Methods:This study analysed the association of E2F-1 with tumour cell proliferation and apoptosis and the upstream regulators modulating these processes, and its impact on patient outcome. Tumour cell proliferation and apoptosis were assessed as percentage of MIB-1 positive or apoptotic cells (MIB-1 labelling index (MI) and apoptotic index (AI)), respectively.Results:Entire specimens showed abnormal expression of one or more upstream regulators of pRb/E2F-1. Although E2F-1 positivity was not associated with the expression of upstream regulators, it showed a linear and positive correlation with MI but not AI. Patients with high MI, low AI, or high E2F-1 positivity had significantly shorter recurrence free survival. By multivariate analysis, high MI and low AI were independently associated with recurrence free survival, but E2F-1 was not.Conclusions:Increased cell proliferation and decreased apoptosis are associated with adverse prognosis in patients with OSCC. Although E2F-1 remains a controversial prognostic factor, its expression was closely associated with tumour cell proliferation and might influence clinical outcome, mainly via cell cycle progression.
Antistreptokinase antibodies: implications for thrombolysis in a region with endemic streptococcal infection: Table 1
Authors: Blackwell N , Hollins A , Gilmore G , Norton R 
Published: August 2005

Aims:To determine antistreptokinase antibody (anti-SK) titres in patients with the acute coronary syndrome from communities with endemic group A streptococcal infection because of the implications for streptokinase (SK) thrombolysis.Methods:Anti-SK titres were determined using a standard method in 47 consecutive SK naive patients, presenting to the Mt Isa Hospital emergency department, Australia, with an acute coronary syndrome. Both indigenous and non-indigenous subjects were enrolled. Antistreptolysin O (ASOT) and anti-DNAse B (ADB) titres were also determined.Results:Indigenous patients were more likely to have anti-SK antibodies (p < 0.001) than the non-indigenous cohort. Anti-SK antibody titres also correlated well with ASOT/ADB titres.Conclusions:Anti-SK antibodies are highly prevalent in SK naive indigenous patients presenting with the acute coronary syndrome. Streptokinase should not be used for thrombolysis in populations with endemic group A streptococcal infection.
Can urine dipstick testing for urinary tract infection at point of care reduce laboratory workload?
Authors: Patel H D , Livsey S A , Swann R A , Bukhari S S 
Published: August 2005

Aim:The University Hospitals of Leicester NHS Trust microbiology laboratory receives 150 000 urine samples each year, approximately 80% of which prove to be culture negative. The aim of this study was to reduce the proportion of culture negative urines arriving in the laboratory, by producing local evidence based guidelines for the use of urine dipstick testing at point of care within the trust’s three acute hospitals.Methods:One thousand and seventy six unborated urine samples were dipstick tested at the point of care using an automatic strip reader. Quantitative results for the four infection associated markers—leucocyte esterase, nitrite, blood, and protein—were compared with the results of conventional laboratory microscopy and culture.Results:The performance of different marker combinations was calculated against the routine laboratory methods. One hundred and seventy five (16.3%) samples were negative for all four markers. Of these dipstick negative samples, only three (1.7% of all true positives) were positive by culture. The absence of all four infection associated markers was found to have a greater than 98% negative predictive value and a sensitivity and specificity of 98.3% and 19.2%, respectively.Conclusions:A urinary dipstick testing algorithm for infection associated markers was derived for use in hospital patients to screen out negative urines. Two years after distributing the algorithm and promoting access to reagent strips and strip readers, a reduction in the urine workload has been seen against an otherwise increasing laboratory specimen load.