bluuebunny/crossref_metadata_2025 huggingface dataset:
Relationship between In Vitro Activities of Amphotericin B and Flucytosine and pH for Clinical Yeast and Mold Isolates
Authors: te Dorsthorst D. T. A. , Verweij P. E. , Meis J. F. G. M. , Mouton J. W.
Published: July 2005

In this study, we investigated the pH dependency of the in vitro activities of amphotericin B (AMB) and flucytosine (5FC) against
Candida
spp.,
Cryptococcus neoformans
,
Aspergillus fumigatus
,
Rhizopus
spp., and
Scedosporium prolificans
in RPMI 1640 buffered with citrate buffer (pH 4.0, 5.0, 5.4, and 6.0), citrate-phosphate buffer (pH 5.4, 6.0, 6.4, and 7.0), and 3-[
N
-morpholino]propanesulfonic acid (MOPS) (pH 6.4, 7.0, 7.4, and 7.9). For 5FC, no significant differences were found between MICs obtained with the different buffers, while for AMB, significant differences were found. The MICs obtained with citrate-phosphate buffer were approximately 1 twofold-dilution step higher than the MICs obtained with MOPS. We demonstrated that the in vitro activities of AMB and 5FC against yeast and mold isolates were pH dependent. The in vitro activity of AMB decreased when the pH was lowered, while the in vitro activity of 5FC increased. The effect of the pH on the in vitro activities was dependent not only on the antifungal agent tested but also on the microorganism. For AMB, there was a nonlinear relationship (median
r
2
, 0.864) for
Candida
spp.,
C. neoformans
,
A. fumigatus
, and
Rhizopus
spp. over the pH range tested. The mean MICs ranged from 0.5 to 2.52 μg/ml at pH 7.0 and from 20.16 to 32 μg/ml at pH 5.0. For
S. prolificans
, there was no relationship. For 5FC, there was a linear relationship for
Candida
spp. (median
r
2
, 0.767) and a nonlinear relationship for
C. neoformans
and
A. fumigatus
(median
r
2
, 0.882) over the pH range tested. The mean MIC values ranged from 0.125 to 1,024 μg/ml at pH 7.0 and from 0.02 to 4 μg/ml at pH 5.0. For
Rhizopus
spp. and
S. prolificans
, the relationship could not be determined, since the MIC was >1,024 μg/ml over a pH range of 4.0 to 7.9.
Role of Efflux Pumps and Topoisomerase Mutations in Fluoroquinolone Resistance in
Campylobacter jejuni
and
Campylobacter coli
Authors: Ge Beilei , McDermott Patrick F. , White David G. , Meng Jianghong
Published: July 2005

Point mutations in the topoisomerase (DNA gyrase A) gene are known to be associated with fluoroquinolone resistance in
Campylobacter
. Recent studies have shown that an efflux pump encoded by
cmeABC
is also involved in decreased susceptibilities to fluoroquinolones, as well as other antimicrobials. Genome analysis suggests that
Campylobacter jejuni
contains at least nine other putative efflux pumps. Using insertional inactivation and site-directed mutagenesis, we investigated the potential contributions of these pumps to susceptibilities to chloramphenicol, ciprofloxacin, erythromycin, and tetracycline in
C. jejuni
and
Campylobacter coli
. Insertional inactivation of
cmeB
resulted in 4- to 256-fold decreases in the MICs of chloramphenicol, ciprofloxacin, erythromycin, and tetracycline, with erythromycin being the most significantly affected. In contrast, inactivation of all other putative efflux pumps had no effect on susceptibility to any of the four antimicrobials tested. Mutation of
gyrA
at codon 86 (Thr-Ile) caused 128- and 64-fold increases in the MICs of ciprofloxacin and nalidixic acid, respectively. The replacement of the mutated
gyrA
with a wild-type
gyrA
allele resulted in a 32-fold decrease in the ciprofloxacin MIC and no change in the nalidixic acid MIC. Our findings indicate that CmeABC is the only efflux pump among those tested that influences antimicrobial resistance in
Campylobacter
and that a point mutation (Thr-86-Ile) in
gyrA
directly causes fluoroquinolone resistance in
Campylobacter
. These two mechanisms work synergistically in acquiring and maintaining fluoroquinolone resistance in
Campylobacter
species.
Population Pharmacokinetics of Tenofovir in Human Immunodeficiency Virus-Infected Patients Taking Highly Active Antiretroviral Therapy
Authors: Jullien Vincent , Tréluyer Jean-Marc , Rey Elisabeth , Jaffray Patrick , Krivine Anne , Moachon Laurence , Lillo-Le Louet Agnès , Lescoat Anne , Dupin Nicolas , Salmon Dominique , Pons Gérard , Urien Saïk
Published: July 2005

The influence of renal function on tenofovir pharmacokinetics was investigated in 193 human immunodeficiency virus (HIV)-infected patients by the use of a population approach performed with the nonlinear mixed effects modeling program NONMEM. Tenofovir pharmacokinetics was well described by a two-compartment open model in which the absorption and the distribution rate constants are equal. Typical population estimates of apparent central distribution volume (

V
c

/
F
), peripheral distribution volume (

V
p

/
F
), intercompartmental clearance (
Q
/
F
), and plasma clearance (CL/
F
) were 534 liters, 1,530 liters, 144 liters/h and 90.9 liters/h, respectively. Apparent plasma clearance was related to body weight/serum creatinine ratio (BW/S
CR
) and to the existence of a tubular dysfunction. Concomitant treatment with lopinavir/ritonavir was found to decrease tenofovir clearance. Individual Bayesian estimates of CL/
F
were used to calculate the tenofovir area under the concentration-time curve from time zero to 24 h (AUC
0-24
). In patients without tubular dysfunction, AUC
0-24
values markedly decreased from 6.7 to 1.4 mg · h/liter for BW/S
CR
increasing from 0.44 to 1.73. The relevance of a dosage adjustment based on BW/S
CR
should be further evaluated.
Fluorescence Polarization Method To Characterize Macrolide-Ribosome Interactions
Authors: Yan Kang , Hunt Eric , Berge John , May Earl , Copeland Robert A. , Gontarek Richard R.
Published: July 2005

A fluorescence polarization assay is described that measures the binding of fluorescently labeled erythromycin to 70S ribosomes fromEscherichia coliand the displacement of the erythromycin from these ribosomes. The assay has been validated with several macrolide derivatives and other known antibiotics. We demonstrate that this assay is suitable for determining the dissociation constants of novel compounds that have binding sites overlapping those of macrolides. This homogeneous binding assay provides a valuable tool for defining structure-activity relationships among compounds during the discovery and development of new ribosome-targeting drugs.
Amprenavir and Efavirenz Pharmacokinetics before and after the Addition of Nelfinavir, Indinavir, Ritonavir, or Saquinavir in Seronegative Individuals
Authors: Morse Gene D. , Rosenkranz Susan , Para Michael F. , Segal Yoninah , DiFrancesco Robin , Adams Elizabeth , Brizz Barbara , Yarasheski Kevin E. , Reichman Richard C.
Published: July 2005

Adult AIDS Clinical Trials Group 5043 examined pharmacokinetic (PK) interactions between amprenavir (APV) and efavirenz (EFV) both by themselves and when nelfinavir (NFV), indinavir (IDV), ritonavir (RTV), or saquinavir (SQV) is added. A PK study was conducted after the administration of single doses of APV (day 0). Subjects (n= 56) received 600 mg of EFV every 24 h (q24h) for 10 days and restarted APV with EFV for days 11 to 13 with a PK study on day 14. A second protease inhibitor (PI) (NFV, 1,250 mg, q12h; IDV, 1,200 mg, q12h; RTV, 100 mg, q12h; or SQV, 1,600 mg, q12h) was added to APV and EFV on day 15, and a PK study was conducted on day 21. Controls continued APV and EFV without a second PI. Among subjects, the APV areas under the curve (AUCs) on days 0, 14, and 21 were compared using the Wilcoxon signed-rank test. Ninety-percent confidence intervals around the geometric mean ratios (GMR) were calculated. APV AUCs were 46% to 61% lower (median percentage of AUC) with EFV (day 14 versus day 0;Pvalues of <0.05). In the NFV, IDV, and RTV groups, day 21 APV AUCs with EFV were higher than AUCs for EFV alone. Ninety-percent confidence intervals around the GMR were 3.5 to 5.3 for NFV (P< 0.001), 2.8 to 4.5 for IDV (P< 0.001), and 7.8 to 11.5 for RTV (P= 0.004). Saquinavir modestly increased the APV AUCs (GMR, 1.0 to 1.4;P= 0.106). Control group AUCs were lower on day 21 compared to those on day 14 (GMR, 0.7 to 1.0;P= 0.042). African-American non-Hispanics had higher day 14 efavirenz AUCs than white non-Hispanics. We conclude that EFV lowered APV AUCs, but nelfinavir, indinavir, or ritonavir compensated for EFV induction.
Human Lactoferricin Is Partially Folded in Aqueous Solution and Is Better Stabilized in a Membrane Mimetic Solvent
Authors: Hunter Howard N. , Demcoe A. Ross , Jenssen Håvard , Gutteberg Tore J. , Vogel Hans J.
Published: July 2005

Lactoferricins are highly basic bioactive peptides that are released in the stomach through proteolytic cleavage of various lactoferrin proteins. Here we have determined the solution structure of human lactoferricin (LfcinH) by conventional two-dimensional nuclear magnetic resonance methods in both aqueous solution and a membrane mimetic solvent. Unlike the 25-residue bovine lactoferricin (LfcinB), which adopts a somewhat distorted antiparallel β sheet, the longer LfcinH peptide shows a helical content from Gln14 to Lys29 in the membrane mimetic solvent but a nonexistent β-sheet character in either the N- or C-terminal regions of the peptide. The helical characteristic of the LfcinH peptide resembles the conformation that this region adopts in the crystal structure of the intact protein. The LfcinH structure determined in aqueous solution displays a nascent helix in the form of a coiled conformation in the region from Gln14 to Lys29. Numerous hydrophobic interactions create the basis for the better-defined overall structure observed in the membrane mimetic solvent. The 49-residue LfcinH peptide isolated for these studies was found to be slightly longer than previously reported peptide preparations and was found to have an intact peptide bond between residues Ala11 and Val12. The distinct solution structures of LfcinH and LfcinB represent a novel difference in the physical properties of these two peptides, which contributes to their unique physiological activities.
DNA Microarray-Based Identification of Genes Associated with Glycopeptide Resistance in
Staphylococcus aureus
Authors: Cui Longzhu , Lian Jian-Qi , Neoh Hui-min , Reyes Ethel , Hiramatsu Keiichi
Published: July 2005

Six pairs of transcription profiles between glycopeptide-intermediate
S. aureus
(GISA [or vancomycin-intermediate
S. aureus
; VISA]) and glycopeptide-susceptible
S. aureus
(vancomycin-susceptible
S. aureus
[VSSA], including glycopeptide-susceptible isogenic mutants from VISA) strains were compared using a microarray. Ninety-two open reading frames which were or tended to be increased in transcription in VISA in at least five out of six array combination pairs were evaluated for their effects on glycopeptide susceptibility by introducing these genes one by one into VSSA strain N315 to construct an overexpression library. By screening the library, 17 genes including 8 novel genes were identified as associated with glycopeptide resistance since their experimental overexpression reduced vancomycin and/or teicoplanin susceptibility of N315. The raised MICs of vancomycin and teicoplanin were 1.25 to 3.0 and 1.5 to 6.0 mg/liter, respectively, as compared to 1.0 mg/liter of N315. Three of these genes, namely
graF
,
msrA2
, and
mgrA
, also raised the oxacillin MIC from 8.0 mg/liter for N315 to 64 to ∼128 mg/liter when they were overexpressed in N315. Their contribution to vancomycin and beta-lactam resistance was further supported by gene knockout and
trans
-complementation assay. By using a plasmid-based promoter-green fluorescent protein gene (
gfp
) transcriptional fusion system,
graF
promoter-activated cells were purified, and subsequent susceptibility tests and Northern blot analysis demonstrated that the cells with up-regulated activity of
graF
promoter showed reduced susceptibility to vancomycin, teicoplanin, and oxacillin. In addition, cell morphology studies showed that
graF
and
msrA2
overexpression increased cell wall thickness of N315 by factors of 23.91 and 22.27%, respectively, accompanied by glycopeptide MIC increments of 3- to 6-fold, when they were overexpressed in N315. Moreover, extended experiments and analyses indicate that many of the genes identified above are related to the cell wall biosynthetic pathway, including active nutrient transport systems. We propose that the genes which raise glycopeptide resistance in
S. aureus
function toward altering the cell wall metabolic pathway.
Development and Validation of a Whole-Cell Inhibition Assay for Bacterial Methionine Aminopeptidase by Surface-Enhanced Laser Desorption Ionization-Time of Flight Mass Spectrometry
Authors: Greis Kenneth D. , Zhou Songtao , Siehnel Richard , Klanke Chuck , Curnow Alan , Howard Jeremy , Layh-Schmitt Gerlinde
Published: July 2005

Bacterial methionine aminopeptidase (MAP) is a protease that removes methionine from the N termini of newly synthesized bacterial proteins after the peptide deformylase enzyme cleaves the formyl group from the initiator formylmethionine. MAP is an essential bacterial gene product and thus represents a potential target for therapeutic intervention. A fundamental challenge in the antibacterial drug discovery field is demonstrating conclusively that compounds with in vitro enzyme inhibition activity produce the desired antibacterial effect by interfering with the same target in whole bacterial cells. One way to address the activity of inhibitor compounds is by profiling cellular biomarkers in whole bacterial cells using compounds that are known inhibitors of a particular target. However, in the case of MAP, no specific inhibitors were available for such studies. Instead, a genetically attenuated MAP strain was generated in which MAP expression was placed under the control of an inducible arabinose promoter. Thus, MAP inhibition in whole cells could be mimicked by growth in the absence of arabinose. This genetically attenuated strain was used as a benchmark for MAP inhibition by profiling whole-cell lysates for unprocessed proteins using surface-enhanced laser desorption ionization-time of flight mass spectrometry (MS). Eight proteins between 4 and 14 kDa were confirmed as being unprocessed and containing the initiator methionine by adding back purified MAP to the preparations prior to MS analysis. Upon establishing these unprocessed proteins as biomarkers for MAP inhibition, the assay was used to screen small-molecule chemical inhibitors of purified MAP for whole-cell activity. Fifteen compound classes yielded three classes of compound with whole-cell activity for further optimization by chemical expansion. This report presents the development, validation, and implementation of a whole-cell inhibition assay for MAP.
Functional Analysis of Ca
IPT1
, a Sphingolipid Biosynthetic Gene Involved in Multidrug Resistance and Morphogenesis of
Candida albicans
Authors: Prasad Tulika , Saini Preeti , Gaur Naseem Akhtar , Vishwakarma Ram A. , Khan Luqman Ahmad , Haq Qazi M. Rizwanul , Prasad Rajendra
Published: July 2005

In the present study we describe the isolation and functional analysis of a sphingolipid biosynthetic gene,
IPT1
, of
Candida albicans
. The functional consequence of the disruption of both alleles of
IPT1
was confirmed by mass analysis of its sphingolipid composition. The disruption of both alleles or a single allele of
IPT1
did not lead to any change in growth phenotype or total sphingolipid, ergosterol, or phospholipid content of the mutant cells. The loss of mannosyl diinositol diphosphoceramide [M(IP)
2
C] in the
ipt1
disruptant, however, resulted in increased sensitivity to drugs like 4-nitroquinoline oxide, terbinafine,
o
-phenanthroline, fluconazole, itraconazole, and ketoconazole. The increase in drug susceptibilities of
ipt1
cells was linked to an altered sphingolipid composition, which appeared to be due to the impaired functionality of Cdr1p, a major drug efflux pump of
C. albicans
that belongs to the ATP binding cassette superfamily. Our confocal and Western blotting results demonstrated that surface localization of green fluorescent protein-tagged Cdr1p was affected in
ipt1
disruptant cells. Poor surface localization of Cdr1p resulted in an impaired ability to efflux fluconazole and rhodamine 6G. The effect of mannosyl inositol phosphoceramide accumulation in the
ipt1
mutant and the absence of M(IP)
2
C from the
ipt1
mutant on the efflux of drug substrates was very selective. The efflux of methotrexate, a specific substrate of CaMdr1p, another major efflux pump of major facilitator superfamily, remained unaffected in
ipt1
mutant cells. Interestingly, changes in sphingolipid composition affected the ability of mutant cells to form proper hyphae in various media. Taken together, our results demonstrate that an altered composition of sphingolipid, which is among the major constituents of membrane rafts, affects the drug susceptibilities and morphogenesis of
C. albicans
.
Six Groups of the OXY β-Lactamase Evolved over Millions of Years in
Klebsiella oxytoca
Authors: Fevre Cindy , Jbel Mehdi , Passet Virginie , Weill François-Xavier , Grimont Patrick A. D. , Brisse Sylvain
Published: July 2005

The diversity and evolution of the class A OXY β-lactamase from
Klebsiella oxytoca
were investigated and compared to housekeeping gene diversity. The entire
bla
OXY
coding region was sequenced in 18 clinical isolates representative of
the four
K. oxytoca
β-lactamase gene groups
bla
OXY-1
to
bla
OXY-4
and of two
new groups identified here,
bla
OXY-5
(with four isolates with pI 7.2 and one with pI 7.7) and
bla
OXY-6
(with four isolates with pI 7.75 and three with pI 8.1). Genes
bla
OXY-5
and
bla
OXY-6
showed 99.8% within-group nucleotide similarity but differed from each other by 4.2% and from
bla
OXY-1
, their closest relative, by 2.5% and 2.9%, respectively. Antimicrobial susceptibility to β-lactams was
similar among OXY groups. Nucleotide sequence diversity of the 16S rRNA (1,454 bp),
rpoB
(940 bp),
gyrA
(383 bp), and
gapDH
(573 bp) genes was in agreement with the β-lactamase gene phylogeny. Strains with
bla
OXY-1
,
bla
OXY-2
,
bla
OXY-3
,
bla
OXY-4
, and
bla
OXY-6
genes formed five phylogenetic groups, named KoI, KoII, KoIII, KoIV, and KoVI, respectively. Isolates
harboring
bla
OXY-5
appeared to represent an emerging lineage within KoI. We estimated that the
bla
OXY
gene has been evolving within
K. oxytoca
for approximately 100 million years, using as
calibration the 140-million-year estimation of the
Escherichia coli
-
Salmonella enterica
split. These
results show that the
bla
OXY
gene has diversified along
K. oxytoca
phylogenetic lines over long periods
of time without concomitant evolution of the antimicrobial resistance phenotype.
Highly Potent Inhibition of Human Immunodeficiency Virus Type 1 Replication by TAK-220, an Orally Bioavailable Small-Molecule CCR5 Antagonist
Authors: Takashima Katsunori , Miyake Hiroshi , Kanzaki Naoyuki , Tagawa Yoshihiko , Wang Xin , Sugihara Yoshihiro , Iizawa Yuji , Baba Masanori
Published: July 2005

TAK-220 is a member of a novel class of chemokine receptor antagonists and is highly specific to CCR5, as determined by receptor binding and calcium mobilization assays. The compound selectively inhibited coreceptor-mediated entry of human immunodeficiency virus type 1 (HIV-1) into host cells and HIV-1 infection mediated by CCR5. TAK-220 inhibited the replication of six CCR5-using (R5) HIV-1 clinical isolates in peripheral blood mononuclear cells (PBMCs) with a mean 90% effective concentration of 13 nM. The anti-HIV-1 activity of TAK-220 was not affected by addition of high concentrations of human serum. It equally inhibited R5 HIV-1 replication in PBMCs obtained from eight different donors, irrespective of the levels of viral production. Furthermore, the anti-HIV-1 activity of TAK-220 was found to be subtype independent. TAK-220 did not induce CCR5 internalization but blocked the binding of two monoclonal antibodies that recognize the second extracellular loop of CCR5 in CCR5-expressing cells. These results suggest that TAK-220 selectively inhibits R5 HIV-1 replication by interfering with coreceptor-mediated entry of the virus into host cells. At a dose of 5 mg/kg of body weight, TAK-220 showed oral bioavailabilities of 9.5 and 28.9% in rats and monkeys, respectively. Thus, TAK-220 is a promising candidate for the treatment of HIV-1 infection.
Caspofungin Susceptibility Testing of
Candida inconspicua
: Correlation of Different Methods with the Minimal Fungicidal Concentration
Authors: Majoros L. , Kardos G. , Szabó B. , Sipiczki M.
Published: July 2005

Minimal inhibitory and minimal fungicidal concentrations of caspofungin were determined for 48
Candida inconspicua
isolates. By using CLSI (formerly NCCLS) methodology with the partial inhibition endpoint criterion, caspofungin exhibited a good fungicidal effect against
C. inconspicua
(the MIC
90
was 0.25 μg/ml and the minimum fungicidal concentration [MFC] was 0.5 μg/ml after 24 h). Total inhibition yielded falsely elevated MICs, exceeding even the respective MFCs.
In Vitro Efficacy of the Combination of Ciprofloxacin and Cefotaxime against
Vibrio vulnificus
Authors: Kim Dong-Min , Lym Yong , Jang Sook Jin , Han Hulin , Kim Young Gi , Chung Choon-Hae , Hong Soon Pyo
Published: July 2005

We performed time-kill studies of antimicrobial combinations that included minocycline, cefotaxime, and ciprofloxacin with
Vibrio vulnificus
ATCC 27562. Cefotaxime-plus-ciprofloxacin combinations acted synergistically against
V. vulnificus
in vitro, and this combination regimen can be a good choice as the empirical treatment for suspected necrotizing fasciitis due to
V. vulnificus
.
Antifungal Susceptibility of 596
Aspergillus fumigatus
Strains Isolated from Outdoor Air, Hospital Air, and Clinical Samples: Analysis by Site of Isolation
Authors: Guinea J. , Peláez T. , Alcalá L. , Ruiz-Serrano M. J. , Bouza E.
Published: July 2005

We analyzed the activities of six antifungal drugs (amphotericin B, itraconazole, voriconazole, posaconazole, caspofungin, and micafungin) against 596
Aspergillus fumigatus
strains isolated from outdoor air, hospital air, and clinical samples. We did not find differences among the susceptibilities by site of isolation.
Preincubation of Pneumococci with β-Lactams Alone or Combined with Levofloxacin Prevents Quinolone-Induced Resistance without Increasing Intracellular Levels of Levofloxacin
Authors: Cottagnoud Philippe , Johnson Maggie , Cottagnoud Marianne , Piddock Laura
Published: July 2005

Preincubation of pneumococci with sub-MIC concentrations of ceftriaxone (1/16× MIC), cefotaxime (1/8× MIC), and meropenem (1/4× MIC) alone or combined with levofloxacin (1/8× MIC) over 6 h prevents the emergence of levofloxacin-resistant mutants after 96 h of incubation but does not affect the intracellular accumulation of levofloxacin in two penicillin-resistant pneumococcal strains, suggesting a link between the mechanism of action of β-lactams and the emergence of quinolone-induced resistance in pneumococci.
Origin of Plasmid-Mediated Quinolone Resistance Determinant QnrA
Authors: Poirel Laurent , Rodriguez-Martinez Jose-Manuel , Mammeri Hedi , Liard Alain , Nordmann Patrice
Published: July 2005

Plasmid-mediated resistance to quinolones is increasingly reported in studies of
Enterobacteriaceae
. Using a PCR-based strategy, a series of gram-negative species were screened for
qnrA
-like genes.
Shewanella algae
, an environmental species from marine and fresh water, was identified as its reservoir. This is a one of the very few examples of progenitor identification of an acquired antibiotic resistance gene.
Therapeutic Effect of ME1036 on Endocarditis Experimentally Induced by Methicillin-Resistant
Staphylococcus aureus
Authors: Nagura Jun , Kijima Koji , Kurazono Mizuyo , Takahata Sho , Sugano Toshie , Tanaka Yukari , Hirai Yoko , Yamada Keiko , Takayama Yoshihiro , Shitara Eiki , Yonezawa Minoru
Published: July 2005

The efficacy of ME1036, a novel parenteral carbapenem, was compared with that of vancomycin by using a rabbit model of methicillin-resistant
Staphylococcus aureus
(MRSA) endocarditis. Compared with vancomycin, ME1036 reduced the bacterial counts in the vegetations at a lower dosage or over a shorter period of administration when it was used for the treatment of MRSA endocarditis.
Extended-Spectrum-β-Lactamase-Producing
Escherichia coli
Strains Isolated from Farm Animals from 1999 to 2002: Report from the Japanese Veterinary Antimicrobial Resistance Monitoring Program
Authors: Kojima Akemi , Ishii Yoshikazu , Ishihara Kanako , Esaki Hidetake , Asai Tetsuo , Oda Chitose , Tamura Yutaka , Takahashi Toshio , Yamaguchi Keizo
Published: July 2005

A nationwide surveillance for antimicrobial susceptibility in
Escherichia coli
strains isolated from food-producing animals in Japan was conducted from 1999 to 2002. Eighteen cefazolin-resistant
E. coli
strains were isolated from broilers. Six were CTX-M-type producing, and eight were CMY-2 producing, while eight had mutations at the
ampC
promoter region.
Ceftazidime in Acute Myeloid Leukemia Patients with Febrile Neutropenia: Helpfulness of Continuous Intravenous Infusion in Maximizing Pharmacodynamic Exposure
Authors: Pea Federico , Viale Pierluigi , Damiani Daniela , Pavan Federica , Cristini Francesco , Fanin Renato , Furlanut Mario
Published: July 2005

The pharmacokinetic-pharmacodynamic profile of a fixed 6-g daily continuous intravenous infusion of ceftazidime was assessed in 20 febrile neutropenic patients with acute myeloid leukemia. Mean steady-state ceftazidime concentrations averaging 40 mg/liter from day 2 on ensured maximized pharmacodynamic exposure (values close to four to five times the MIC breakpoint against
Pseudomonas aeruginosa
). However, large intra- and interindividual pharmacokinetic variability was documented throughout the study period.
Genotypic Diversity of Methicillin-Resistant
Staphylococcus aureus
Isolates in Korean Hospitals
Authors: Soo Ko Kwan , Kim Yeon-Sook , Song Jae-Hoon , Yeom Joon-Sup , Lee Hyuck , Jung Sook-In , Jeong Doo-Ryun , Kim Shin-Woo , Chang Hyun-Ha , Ki Hyun Kyun , Moon Chisook , Oh Won Sup , Peck Kyong Ran , Lee Nam Yong
Published: July 2005

Ninety-six methicillin-resistant
Staphylococcus aureus
(MRSA) isolates from eight Korean hospitals were analyzed by multilocus sequence typing, SCC
mec
typing, and
spa
typing. The predominant genotype was ST5-MRSA-II of clonal complex 5, which was found in 36 isolates from six hospitals, but ST239-MRSA-III was also common. Overall, results showed a notable genotypic diversity of MRSA strains circulating in Korean hospitals.
An alternative protocol for DNA extraction from formalin fixed and paraffin wax embedded tissue
Authors: Coura R , Prolla J C , Meurer L , Ashton-Prolla P
Published: July 2005

Background:DNA extraction from paraffin wax embedded tissue requires special protocols, and most described methods report an amplification success rate of 60–80%.

Aims:To propose a simple and inexpensive protocol consisting of xylene/ethanol dewaxing, followed by a kit based extraction.

Method:Xylene/ethanol dewaxing was followed by a long rehydration step and a kit based DNA extraction step.

Results:This method produced a 100% amplification success rate for fragments of 121 to 227 bp for tamponated formalin fixed paraffin wax embedded tissue.

Conclusion:This cost effective and non-laborious protocol can successfully extract DNA from tamponated formalin fixed paraffin wax embedded tissue and should facilitate the molecular analysis of a large number of archival specimens in retrospective studies.
A teratoid cyst containing nephrogenic tissue in a woman with a horseshoe kidney
Authors: Stewart G D , Bariol S V , Grigor K M , Tolley D A
Published: July 2005

A 21 year old woman presenting with flank pain and vomiting was found to have a cystic lesion associated with a horseshoe kidney. The inner aspect of the cyst wall consisted of connective tissue intermingled with colonic-type epithelium. Within the cyst wall there were multiple foci of immature and incompletely differentiated renal elements, together with fragments of urothelium, smooth muscle, bone, and neuroendocrine tissue. No immature renal blastema were found. This lesion is unique and labelled as a teratoid cyst containing nephrogenic tissue.
Combined fibrolamellar carcinoma and cholangiocarcinoma exhibiting biphenotypic antigen expression: a case report
Authors: Tanaka K , Honna T , Kitano Y , Kuroda T , Tanaka K , Morikawa N , Matsuda H , Kawashima N , Matsuoka K , Miyauchi J
Published: July 2005

Fibrolamellar carcinoma (FLC), a variant of hepatocellular carcinoma (HCC), very rarely occurs in association with cholangiocarcinoma (CC). This report describes the first case of FLC coexisting with CC (FLC-CC) from Japan. Although the major part of the tumour located in the right lobe of the liver showed the typical features of FLC, CC was admixed with the FLC, not only in the primary hepatic tumour, but also in the lymph node metastases. Immunohistochemical analysis revealed that, although carcinoembryonic antigen (CEA), which can be detected with monoclonal antibodies in the cytoplasm and the cell surface of CC cells but not HCC cells, was expressed in only the CC cells in the primary tumour, it was expressed extensively in the cytoplasm of both CC and FLC cells in the metastatic and recurrent tumours. Furthermore, Hep Par 1, a hepatocyte specific antigen, was also expressed in both the FLC and CC cells. These findings suggest that, in this case, both FLC and CC were possibly derived from the same cancer stem cell with the capacity to differentiate into both hepatocytes and bile duct epithelium, and that both the cellular components, therefore, exhibited biphenotypic antigen expression.
Uterine tumour resembling an ovarian sex cord tumour
Authors: Sutak J , Lazic D , Cullimore J E
Published: July 2005

Endometrial stromal sarcomas account for 0.25% of all uterine malignancies. These tumours were originally divided into low grade and high grade stromal sarcomas, but the recent World Health Organisation classification (2003) recognises low grade stromal sarcoma and undifferentiated endometrial sarcoma. Low grade sarcomas may exhibit other forms of differentiation, including smooth muscle and sex cord differentiation. In the latter form, the tumour contains epithelial-like or sex cord-like elements often with epithelioid appearance, arranged in nests, cords, trabeculae, solid, or tubular structures. If this element predominates, the tumour is considered to be a uterine tumour resembling ovarian sex cord tumour, and may cause diagnostic difficulties. This case report describes the histological and immunohistochemical features of a uterine stromal sarcoma showing exclusively a pattern reminiscent of ovarian sex cord tumour.
Association of chronic fatigue syndrome with human leucocyte antigen class II alleles
Authors: Smith J , Fritz E L , Kerr J R , Cleare A J , Wessely S , Mattey D L
Published: July 2005

Background:A genetic component to the development of chronic fatigue syndrome (CFS) has been proposed, and a possible association between human leucocyte antigen (HLA) class II antigens and chronic fatigue immune dysfunction has been shown in some, but not all, studies.

Aims:To investigate the role of HLA class II antigens in CFS.

Methods:Forty nine patients with CFS were genotyped for the HLA-DRB1, HLA-DQA1, and HLA-DQB1 alleles and the frequency of these alleles was compared with a control group comprising 102 normal individuals from the UK. All patients and controls were from the same region of England and, apart from two patients, were white.

Results:Analysis by 2 × 2 contingency tables revealed an increased frequency of HLA-DQA1*01 alleles in patients with CFS (51.0%v35%; odds ratio (OR), 1.93; p  =  0.008). HLA-DQB1*06 was also increased in the patients with CFS (30.2%v20.0%; OR, 1.73, p  =  0.052). Only the association between HLA-DQA1*01 and CFS was significant in logistic regression models containing HLA-DQA1*01 and HLA-DRQB1*06, and this was independent of HLA-DRB1 alleles. There was a decreased expression of HLA-DRB1*11 in CFS, although this association disappeared after correction for multiple comparisons.

Conclusions:CFS may be associated with HLA-DQA1*01, although a role for other genes in linkage disequilibrium cannot be ruled out.
Parvovirus B19 infection associated with unilateral cervical lymphadenopathy, apoptotic sinus histiocytosis, and prolonged fatigue
Authors: Knösel T , Meisel H , Borgmann A , Riebel T , Krenn V , Schewe C , Petersen I
Published: July 2005

This report describes the case of a 16 year old girl with a history of high fever, prolonged fatigue, and cervical lymphadenopathy of the right side. In addition, the patient showed neutropenia, thrombopenia, and pronounced reticulopenia. Cervical ultrasound showed unilateral hypoechoic lymph nodes up to 23 mm in diameter suspicious for malignant lymphoma. Histology of a cervical lymph node specimen revealed massive nodular histiocytic proliferation and prominent apoptosis without necrosis. Parvovirus B19 was detected by polymerase chain reaction and immunohistochemistry in the lymph node. In summary, this case is an unusual presentation of parvovirus B19 infection. The virus was identified as the potential causative agent of unilateral cervical lymphoma and apoptotic sinus histocytosis, thus broadening the clinicopathological spectrum of parvovirus B19 induced diseases.
Expression of human telomerase catalytic protein in gallbladder carcinogenesis
Authors: Luzar B , Poljak M , Cör A , Klopc̆ic̆ U , Ferlan-Marolt V
Published: July 2005

Background:Telomerase catalytic subunit (hTERT) gene re-expression is a rate limiting step for the activity of telomerase, a key enzyme implicated in cellular immortalisation and transformation.

Aims:To determine the potential role of hTERT protein in gallbladder carcinogenesis.

Material/Methods:hTERT protein was analysed by means of immunohistochemistry in 89 gallbladder tissue samples: 16 normal epithelia, 14 reactive hyperplasias, 15 low grade dysplasias, 16 high grade dysplasias, and 28 adenocarcinomas. At least 200 nuclei were assessed for each slide and the mean number of positive signals for each nucleus was expressed as the hTERT index.

Results:The mean hTERT index increased progressively with the degree of gallbladder epithelial abnormalities: from 0.03 in normal epithelia, 0.04 in hyperplastic epithelia, 0.25 in low grade dysplasia, 0.82 in high grade dysplasia, to 0.93 in adenocarcinoma. Statistical analysis revealed that three different groups of gallbladder epithelial changes can be distinguished according to the number of hTERT signals for each nucleus: (1) normal and regenerative gallbladder epithelium, (2) low grade dysplasia, and (3) high grade dysplasia and adenocarcinoma (p < 0.001).

Conclusions:The occasional presence of hTERT protein in normal and regenerative gallbladder mucosa reflects their regenerative capacity. Nevertheless, significantly higher hTERT indices in low and high grade dysplastic epithelia and in gallbladder adenocarcinomas are probably a consequence of hTERT re-expression—an early event in the multistep process of gallbladder carcinogenesis.
Expression of p-STAT3 in human colorectal adenocarcinoma and adenoma; correlation with clinicopathological factors
Authors: Kusaba T , Nakayama T , Yamazumi K , Yakata Y , Yoshizaki A , Nagayasu T , Sekine I
Published: July 2005

Background:The signal transducer and activator of transcription 3 (STAT3) is a key signalling molecule implicated in the regulation of growth and malignant transformation. Constitutive activation of STAT3 is seen in several tumour derived cell lines, and in a wide variety of human malignancies.

Aims:To examine the relation between p-STAT3 (activated form of STAT3) expression and clinicopathological factors in human colorectal adenocarcinoma and adenoma.

Methods:Immunohistochemical analyses were carried out on tissues from 44 colorectal adenomas and 95 colorectal adenocarcinomas, comprising 18 intramucosal carcinomas and 77 invasive carcinomas.

Results:Seventy seven of these 139 samples (55.4%) showed immunoreactivity for p-STAT3. Positive staining for p-STAT3 was seen in 69 of the 95 carcinomas. Only eight of the 44 adenomas showed immunopositivity for p-STAT3, resulting in a significant difference between total adenocarcinomas and adenomas (p < 0.001). Among the 95 cases of colorectal adenocarcinoma, p-STAT3 immunoreactivity was significantly correlated with the depth of tumour invasion (p < 0.05), venous invasion (p < 0.05), lymph node metastasis (p < 0.05), and increasing stages of the Dukes’ classification (p < 0.01). Expression of p-STAT3 was detected by Western blot analysis in two different cultured human colorectal carcinoma cell lines and six colon carcinoma tissue samples obtained at surgery.

Conclusion:This is the first study to report a significant correlation of p-STAT3 expression with the depth of tumour invasion. These findings suggest that p-STAT3 expression is an important factor related to carcinogenesis and/or tumour invasion of colorectal adenocarcinoma.
Immunohistochemical and molecular assessment of human herpesvirus type 8 in gastrointestinal tumours
Authors: Su C C , Li C F , Liao Y L , Lin C N , Lu J J
Published: July 2005

Background:Gastrointestinal stromal tumours (GISTs) are the most common mesenchymal tumours of the gastrointestinal tract, histologically identified as highly cellular spindle or epithelioid cell tumours, and often positive for CD34 (60–70%). Kaposi’s sarcomas (KSs) are similar to GISTs: they are most often found in the gastrointestinal tract (although cutaneous lesions do occur), they are also composed of spindle or epithelioid cells (although erythrocytes are also seen), and the tumour cells are nearly all positive for CD34. Human herpesvirus type 8 (HHV-8) DNA has been found consistently in all types of KS, in particular in CD34 positive KS tumour cells. However, the association between HHV-8 and GIST has not been investigated.

Aims:To assess the presence of HHV-8 in GISTs.

Methods:Paraffin wax embedded tissues of 86 primary GISTs and their recurrent or metastatic tumours were analysed immunohistochemically for the CD34 antigen and HHV-8 latent nuclear antigen 1 (LNA-1) and by means of the nested polymerase chain reaction (PCR) and real time PCR for HHV-8 DNA.

Results:None of the 86 GISTs contained HHV-8 DNA sequences or LNA-1 positive cells.

Conclusions:These results demonstrate the lack of HHV-8 infection in GIST tumour cells. HHV-8 does not appear to play a role in the pathogenesis of GIST, irrespective of the status of the tumour.
Discordant quantitative detection of putative biomarkers in nodal micrometastases of colorectal cancer: biological and clinical implications
Authors: Kong S L , Salto-Tellez M , Leong A P K , Chan Y H , Koay E S C
Published: July 2005

Aims:Nodal expression of the carcinoembryonic antigen (CEA), cytokeratin 20 (CK20), and guanylyl cyclase C (GCC) genes was measured in tandem in patients with colorectal cancer (CRC) to assess whether there would be sufficient agreement between these markers in their ability to detect micrometastasis to qualify one of them as a universal marker, and whether frozen and paraffin wax embedded tissues would yield similar results.

Methods:One hundred and seventy five frozen lymph nodes (FT) and 158 formalin fixed, paraffin wax embedded lymph nodes (PET) from 28 CRC cases were analysed using gene specific quantitative real time polymerase chain reaction, carried out on the LightCycler® system with SYBR Green chemistry.

Results:There was significant disparity in positive detection of the three biomarkers in FT versus PET, with notable agreement achieved only for CEA (66.6%) in FT versus PET in Dukes’ B disease, and between CK20 and GCC (44.6%) in FT, also in Dukes’ B disease. One patient with full concordance in all three tumour markers with both tissue types suffered a relapse and died within two years of follow up.

Conclusions:There was considerable discordance in the positive detection of the three tumour markers in both tissue types (FT versus PET). This brings into question whether using a single tumour marker to detect micrometastasis in one tissue type (FT or PET) is adequately representative, and challenges the concept of universal markers for molecular CRC metastatic detection. Multiple tumour markers would predict more accurately the metastatic potential of Dukes’ B CRCs.
Epidural angiolipoma is histologically distinct from its cutaneous counterpart in the calibre and density of its vascular component; a case report with review of the literature
Authors: Hattori H
Published: July 2005

Angiolipoma of the spine is a rare tumour and no studies have investigated a sufficient number of cases to reach general conclusions. Therefore, as yet, the pathological definition of this entity is not well established. The case of epidural angiolipoma reported here and a review of the literature revealed that this entity is distinct from cutaneous angiolipoma in that the calibre of its predominant vascular component is far greater than that of the fat cells. Therefore, epidural angiolipoma can be regarded as not only topographically, but also histologically, distinct from its subcutaneous counterpart.
Coronary artery stents: identification and evaluation
Authors: Butany J , Carmichael K , Leong S W , Collins M J
Published: July 2005

First introduced in the 1980s, the coronary stent has been used to reduce the rate of arterial restenosis. Coronary stent implantation is currently a common procedure performed by interventional cardiologists, and the market for development and design is constantly expanding and evolving. This article was designed to assist pathologists in the accurate identification of coronary stents that are currently available, in addition to some that are no longer being implanted. The stents reviewed here were chosen based on frequency of use and/or occurrence in the literature. Some of the newer models have yet to undergo extensive clinical testing. The summaries accompanying each stent include concise physical descriptions and documented complications, intended to serve as a guide for the investigating pathologist.
Gene expression in peripheral blood mononuclear cells from patients with chronic fatigue syndrome
Authors: Kaushik N , Fear D , Richards S C M , McDermott C R , Nuwaysir E F , Kellam P , Harrison T J , Wilkinson R J , Tyrrell D A J , Holgate S T , Kerr J R
Published: July 2005

Background:Chronic fatigue syndrome (CFS) is a multisystem disease, the pathogenesis of which remains undetermined.

Aims:To test the hypothesis that there are reproducible abnormalities of gene expression in patients with CFS compared with normal healthy persons.

Methods:To gain further insight into the pathogenesis of this disease, gene expression was analysed in peripheral blood mononuclear cells from 25 patients with CFS diagnosed according to the Centers for Disease Control criteria and 25 normal blood donors matched for age, sex, and geographical location, using a single colour microarray representing 9522 human genes. After normalisation, average difference values for each gene were compared between test and control groups using a cutoff fold difference of expression ⩾ 1.5 and a p value of 0.001. Genes showing differential expression were further analysed using Taqman real time polymerase chain reaction (PCR) in fresh samples.

Results:Analysis of microarray data revealed differential expression of 35 genes. Real time PCR confirmed differential expression in the same direction as array results for 16 of these genes, 15 of which were upregulated (ABCD4, PRKCL1, MRPL23, CD2BP2, GSN, NTE, POLR2G, PEX16, EIF2B4, EIF4G1, ANAPC11, PDCD2, KHSRP, BRMS1, and GABARAPL1) and one of which was downregulated (IL-10RA). This profile suggests T cell activation and perturbation of neuronal and mitochondrial function. Upregulation of neuropathy target esterase and eukaryotic translation initiation factor 4G1 may suggest links with organophosphate exposure and virus infection, respectively.

Conclusion:These results suggest that patients with CFS have reproducible alterations in gene regulation.
MULTICAST STATE DISTRIBUTION BY JOINS USING MULTIPLE SHORTEST PATHS
Authors: MAGONI DAMIEN , LORENZ PASCAL
Published: July 2005

The lack of resources in routers will become a crucial issue with the deployment of state storing protocols. In particular, single or any source multicast protocols will most probably take over large amounts of resources for maintaining multicast tree information. The aim of this paper is to study the possibility and benefit of using multiple shortest paths in order for a new member to reach a multicast tree. Such a mechanism would not reduce the overall amount of state information in the network but it would distribute this amount more evenly among all routers. The idea is to use alternate shortest paths provided by the underlying unicast routing protocol to avoid saturated routers, that is, routers that can not or do not want to store any more multicast state information. As the simulation results are very sensitive to the topology, we have used subgraphs of an Internet map. We have then simulated our multipath join mechanism and have found that depending on the tree size, the use of our mechanism can increase successful join attempts by up to 55% when the network is half saturated.
ANOMALOUS SYNCHRONIZATION OF SPATIALLY EXTENDED CHAOTIC SYSTEMS IN THE PRESENCE OF ASYMMETRIC COUPLING
Authors: BOCCALETTI S. , MENDOZA C. , BRAGARD J.
Published: July 2005

This paper describes the effects of an asymmetric coupling in the synchronization of two spatially extended systems. Namely, we report the consequences induced by the presence of asymmetries in the coupling configuration of a pair of one-dimensional fields obeying Complex Ginzburg–Landau equations. While synchronization always occurs for large enough coupling strengths, asymmetries have the effect of enhancing synchronization and play a crucial role in setting the threshold for the appearance of the synchronized dynamics, as well as in selecting the statistical and dynamical properties of the synchronized motion. We discuss the process of synchronization in the presence of asymmetries by using some analytic expansions valid for a regime of soft spatial temporal chaos (i.e. phase turbulence regime). The influence of phase singularities that break the validity of the analysis is also discussed.