bluuebunny/crossref_metadata_2025_split huggingface dataset:
Decolorization of Malachite Green and Crystal Violet by Waterborne Pathogenic Mycobacteria
Authors: Jones Jefferson J. , Falkinham Joseph O. 
Published: June 2003

ABSTRACTMycobacterium avium,Mycobacterium intracellulare,Mycobacterium scrofulaceum,Mycobacterium marinum, andMycobacterium chelonaetolerate high concentrations of the dyes malachite green and crystal violet. Cells of strains of those species decolorized (reduced) both malachite green and crystal violet. Because decolorized malachite green lacked antimicrobial activity, the resistance of these mycobacteria could be due, in part, to their ability to decolorize the dyes. Small amounts of malachite green and its reduced, decolorized product were detected in the lipid fraction ofM. aviumstrain A5 cells grown in the presence of malachite green, suggesting that a minor component of resistance could be due to sequestering the dyes in the extensive mycobacterial cell surface lipid. The membrane fraction ofM. aviumstrain A5 had at least a fivefold-higher specific decolorization rate than did the crude extract, suggesting that the decolorization activity is membrane associated. The malachite green-decolorizing activity of the membrane fraction ofM. aviumstrain A5 was abolished by either boiling or proteinase exposure, suggesting that the decolorizing activity was due to a protein. Decolorization activity of membrane fractions was stimulated by ferrous ion and inhibited by dinitrophenol and metyrapone.
Inhibitory Activities of Quinolones against DNA Gyrase of
Chlamydia pneumoniae
Authors: Ameyama Satoshi , Shinmura Yuko , Takahata Masahiro 
Published: June 2003

ABSTRACT

The
gyrA
and
gyrB
genes of
Chlamydia pneumoniae
TW-183 were cloned, and their proteins were purified by use of a fusion system with a maltose-binding protein. The 50% inhibitory concentrations of garenoxacin, sparfloxacin, moxifloxacin, gatifloxacin, and levofloxacin were 10.1, 47.5, 39.6, 64.2, and 156.9 μg/ml, respectively, and the MICs against
C. pneumoniae
TW-183 were 0.008, 0.016, 0.063, 0.125, and 0.25 μg/ml, respectively.
Sfh-I, a Subclass B2 Metallo-β-Lactamase from a
Serratia fonticola
Environmental Isolate
Authors: Saavedra Maria José , Peixe Luísa , Sousa João Carlos , Henriques Isabel , Alves Artur , Correia António 
Published: June 2003

ABSTRACT

An environmental isolate of
Serratia fonticola
resistant to carbapenems was shown to contain a genetic determinant encoding a metallo-β-lactamase of the subclass B2. The Sfh-I enzyme exhibits some divergence from the previously characterized enzymes of this subclass. This is the first example of a naturally occurring metallo-β-lactamase in
Enterobacteriaceae
.
In Vitro Activities of Ramoplanin, Teicoplanin, Vancomycin, Linezolid, Bacitracin, and Four Other Antimicrobials against Intestinal Anaerobic Bacteria
Authors: Citron D. M. , Merriam C. V. , Tyrrell K. L. , Warren Y. A. , Fernandez H. , Goldstein E. J. C. 
Published: June 2003

ABSTRACT

By using an agar dilution method, the in vitro activities of ramoplanin, teicoplanin, vancomycin, linezolid, and five other agents were determined against 300 gram-positive and 54 gram-negative strains of intestinal anaerobes. Ramoplanin was active at ≤2 μg/ml against 287 of 300 (95.7%) gram-positive organisms, including 18 strains of
Clostridium difficile
for which MICs of ramoplanin were 0.25 to 0.5 μg/ml; for 3 of these, linezolid MICs were 8 to 16 μg/ml. Nineteen
Clostridium innocuum
strains for which the vancomycin MIC at which 90% of strains were inhibited was 16 μg/ml were susceptible to ramoplanin at 0.06 to 0.25 μg/ml and to teicoplanin at 0.125 to 1.0 μg/ml. All strains of
Eubacterium
,
Actinomyces
,
Propionibacterium
, and
Peptostreptococcus
spp. were inhibited by ≤0.25 μg of ramoplanin per ml and ≤1 μg of vancomycin per ml. Ramoplanin was also active at ≤4 μg/ml against 15 of 22 of the
Prevotella
and
Porphyromonas
strains tested, but ramoplanin MICs for all 31 strains of the
Bacteroides fragilis
group, the
Fusobacterium mortiferum-Fusobacterium varium
group, and
Veillonella
spp. were ≥256 μg/ml. Ramoplanin displays excellent activity against
C. difficile
and other gram-positive enteric anaerobes, including vancomycin-resistant strains; however, it has poor activity against most gram-negative anaerobes and thus potentially has a lesser effect on the ecological balance of normal fecal flora.
Scopulariopsis brevicaulis, a Fungal Pathogen Resistant to Broad-Spectrum Antifungal Agents
Authors: Cuenca-Estrella Manuel , Gomez-Lopez Alicia , Mellado Emilia , Buitrago Maria J. , Monzón Araceli , Rodriguez-Tudela Juan L. 
Published: June 2003

ABSTRACTThe antifungal susceptibility results for 32 clinical isolates ofScopulariopsis brevicaulisare presented. Flucytosine and itraconazole were inactive in vitro, and MICs of amphotericin B, voriconazole, and terbinafine for all isolates were high, with geometric means of 13, 25.8, and 14.4 μg/ml, respectively.
In Vitro Susceptibilities ofMalasseziaSpecies to a New Triazole, Albaconazole (UR-9825), and Other Antifungal Compounds
Authors: Garau Margarita , Pereiro Manolo , del Palacio Amalia 
Published: June 2003

ABSTRACTThe in vitro activity of the new triazole albaconazole (UR-9825) in comparison with those of flucytosine, fluconazole, ketoconazole, itraconazole, and voriconazole against 70 strains ofMalasseziaspp. was determined by a microdilution method using a colorimetric indicator for metabolic activity. Albaconazole showed an in vitro profile similar to those of the different antifungals tested (MIC ≤ 0.06 μg/ml for all the strains).
Activity of Telithromycin against Penicillin-Resistant
Streptococcus pneumoniae
Isolates Recovered from French Children with Invasive and Noninvasive Infections
Authors: Bingen Edouard , Doit Catherine , Loukil Chawki , Brahimi Naima , Bidet Philippe , Deforche Dominique , Geslin Pierre 
Published: June 2003

ABSTRACT

We compared the activities of telithromycin, erythromycin, azithromycin, josamycin, penicillin G, amoxicillin, cefpodoxime, and ceftriaxone against invasive and noninvasive non-penicillin-susceptible
Streptococcus pneumoniae
isolates recovered from children. Of the 186 isolates tested, 89% were positive for
erm
(B) by PCR. Telithromycin had the lowest MICs, with MICs at which 90% of the isolates tested are inhibited of 0.032 and 0.25 μg/ml for erythromycin-sensitive and -resistant isolates, respectively.
Development and Validation of a High-Performance Liquid Chromatography Assay for Voriconazole
Authors: Pennick Gennethel J. , Clark Martin , Sutton Deanna A. , Rinaldi Michael G. 
Published: June 2003

ABSTRACT
An analytical method for the determination of voriconazole (UK-109,496; Pfizer) in plasma was developed and validated. The method utilizes solid-phase extraction technology and high-performance liquid chromatography. The lower limit of quantitation is 0.2 μg/ml, and the range of linearity tested was 0.2 to 10 μg/ml.
Intra- and Interindividual Variabilities of Valacyclovir Oral Bioavailability and Effect of Coadministration of an hPEPT1 Inhibitor
Authors: Phan Dana D. , Chin-Hong Peter , Lin Emil T. , Anderle Pascale , Sadee Wolfgang , Guglielmo B. Joseph 
Published: June 2003

ABSTRACT
Variability in valacyclovir bioavailability and the potential for cephalexin-valacyclovir interaction were evaluated. The intraindividual acyclovir area under the concentration-time curve (AUC) varied minimally, whereas interindividual differences were substantial. Coadministration of the human peptide transporter 1 (hPEPT1) substrates valacyclovir and cephalexin minimally reduced the acyclovir AUC. These results suggest a stable valacyclovir absorption phenotype, significant interindividual variability, and minimal interaction between these hPEPT1 substrates.
In Vitro Antimicrobial Susceptibility of
Brachyspira pilosicoli
Isolates from Humans
Authors: Brooke C. J. , Hampson D. J. , Riley T. V. 
Published: June 2003

ABSTRACT

The in vitro antimicrobial susceptibility of the anaerobic intestinal spirochete
Brachyspira pilosicoli
was investigated by an agar dilution method. Human (
n
= 123) and porcine (
n
= 16) isolates were susceptible to metronidazole, ceftriaxone, meropenem, tetracycline, moxifloxacin, and chloramphenicol; erythromycin and ciprofloxacin were not active. Resistance to amoxicillin and clindamycin varied. Amoxicillin susceptibility was restored by clavulanic acid.
Susceptibilities of
Campylobacter jejuni
Isolates from Germany to Ciprofloxacin, Moxifloxacin, Erythromycin, Clindamycin, and Tetracycline
Authors: Wagner Jutta , Jabbusch Miriam , Eisenblätter Martin , Hahn Helmut , Wendt Constanze , Ignatius Ralf 
Published: June 2003

ABSTRACT

To elucidate
Campylobacter jejuni
resistance to antibiotics in Germany, MICs of ciprofloxacin, moxifloxacin, erythromycin, clindamycin, and tetracycline were determined (using agar dilution) for 144 clinical isolates. The data indicate a considerable ciprofloxacin resistance (45.1%) without a clonal relationship of the strains and a greater in vitro activity of moxifloxacin, erythromycin, and clindamycin.
In Vitro Selection and Characterization of
Bacillus anthracis
Mutants with High-Level Resistance to Ciprofloxacin
Authors: Price Lance B. , Vogler Amy , Pearson Talima , Busch Joseph D. , Schupp James M. , Keim Paul 
Published: June 2003

ABSTRACT

Mutants of attenuated
Bacillus anthracis
with high-level ciprofloxacin resistance were isolated using a three-step in vitro selection. Ciprofloxacin MICs were 0.5 μg/ml for first-step mutants, which had one of two
gyrA
quinolone resistance-determining region (QRDR) mutations. Ciprofloxacin MICs were 8 and 16 μg/ml for second-step mutants, which had one of three
parC
QRDR mutations. Ciprofloxacin MICs for third-step mutants were 32 and 64 μg/ml. Mutants for which MICs were 64 μg/ml had one of two additional mutations within the
gyrA
QRDR or one of two mutations within the
gyrB
QRDR. Mutants for which MICs were 32 μg/ml had no additional target modifications but showed evidence of enhanced ciprofloxacin efflux.
Farnesol Biosynthesis in
Candida albicans
: Cellular Response to Sterol Inhibition by Zaragozic Acid B
Authors: Hornby Jacob M. , Kebaara Bessie W. , Nickerson Kenneth W. 
Published: June 2003

ABSTRACT

The dimorphic fungus
Candida albicans
produces farnesol as a quorum-sensing molecule that regulates cellular morphology. The biosynthetic origin of farnesol has been resolved by treating these cells with zaragozic acid B, a potent inhibitor of squalene synthase in the sterol biosynthetic pathway. Treatment with zaragozic acid B leads to an eightfold increase in the amount of farnesol produced by
C. albicans
. Furthermore,
C. albicans
cell extracts contain enzymatic activity to convert [
3
H]farnesyl pyrophosphate to [
3
H]farnesol. Many common antifungal antibiotics (e.g., zaragozic acids, azoles, and allylamines) target steps in sterol biosynthesis. We suggest that the fungicidal activity of zaragozic acid derives in large part from the accumulation of farnesol that accompanies the inhibition of sterol biosynthesis.
Emergence of Macrolide Resistance in Throat Culture Isolates of Group A Streptococci in Ontario, Canada, in 2001
Authors: Katz Kevin C. , McGeer Allison J. , Duncan Carla L. , Ashi-Sulaiman Aisha , Willey Barbara M. , Sarabia Alicia , McCann Jacquie , Pong-Porter Sylvia , Rzayev Yana , de Azavedo Joyce S. , Low Donald E. 
Published: June 2003

ABSTRACT
Of 500 group A streptococci isolated from pharyngeal swabs, 72 (14.4%) were macrolide resistant, compared to 2.1% in 1997. Of these, 66 (92%) were of the M phenotype and 6 (8.3%) were of the MLS phenotype. Pulsed-field gel electrophoresis found that two clones, with patterns identical to those of serotypes M1 and M4, accounted for 19.4 and 68.1% of the macrolide-resistant isolates, respectively.
Addition of Caspofungin to Fluconazole Does Not Improve Outcome in Murine Candidiasis
Authors: Graybill John R. , Bocanegra Rosie , Najvar Laura K. , Hernandez Steve , Larsen Robert A. 
Published: June 2003

ABSTRACT

Caspofungin is a potent antifungal inhibiting glucan synthesis in
Candida
species. However, caspofungin is not 100% curative in candidiasis. Therefore, we evaluated combinations of fluconazole with caspofungin for murine candidemia. We could not show any benefit of combined therapy over individual antifungal drugs.
The M184V Substitution in Human Immunodeficiency Virus Type 1 Reverse Transcriptase Delays the Development of Resistance to Amprenavir and Efavirenz in Subtype B and C Clinical Isolates
Authors: Diallo Karidia , Brenner Bluma , Oliveira Maureen , Moisi Daniela , Detorio Mervi , Götte Matthias , Wainberg Mark A. 
Published: June 2003

ABSTRACTThe M184V substitution in human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT), encoding high-level resistance to lamivudine (3TC), results in decreased HIV-1 replicative capacity, diminished RT processivity, and increased RT fidelity in biochemical assays. We assessed the effect of M184V on the development of resistance to the nonnucleoside RT inhibitors efavirenz (EFV) and nevirapine, and to the protease inhibitor amprenavir (APV) in tissue culture. Genotypic analysis revealed differences in EFV resistance-conferring mutations in subtype B (K103N) versus subtype C (V106 M), and the appearance of both was significantly delayed in the M184V-containing variants compared with the wild type (WT). Similarly, there was a marked delay in the emergence of mutations associated with APV resistance (I54 M/L/V) in subtype B viruses harboring M184V compared with paired WT viral isolates.
Low-Level Endotoxin Induces Potent Inflammatory Activation of Human Blood Vessels
Authors: Rice James B. , Stoll Lynn L. , Li Wei-Gen , Denning Gerene M. , Weydert Jamie , Charipar Elizabeth , Richenbacher Wayne E. , Miller Francis J. , Weintraub Neal L. 
Published: June 2003

Background—Low-level endotoxemia (ie, ≥50 pg/mL) in apparently healthy subjects was recently identified as a powerful, independent risk factor for atherosclerosis.Methods and Results—We treated human saphenous veins (HSVs) with low levels of endotoxin. Release of the proinflammatory chemokines interleukin-8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1) was measured by ELISA. Superoxide was determined by using the fluorescent probe dihydroethidium (HE), and monocyte binding was assessed with calcein-labeled U-937 cells. Three- to 4-fold increases in MCP-1 and IL-8 release were observed at endotoxin concentrations of 100 pg/mL; these increases were inhibited by the 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor atorvastatin. Studies in cultured endothelial cells suggest that the mechanism is related to inhibition of isoprenylation (ie, geranylgeranylation) rather than cholesterol formation. Endotoxin produced dose-dependent increases in HE fluorescence that were inhibited by the superoxide dismutase mimics Tiron and MnTBAP. Endotoxin potently induced U-937 cell binding to HSV; binding was inhibited by both Tiron and atorvastatin. Toll-like receptor-4 expression was detected in cultured HSV endothelial and smooth muscle cells and in intact HSV.Conclusions—Clinically relevant levels of endotoxin, as reported in ambulatory populations, have profound inflammatory effects on intact HSV. Inhibition of endotoxin-induced vascular inflammation might contribute to the beneficial effects of statins in treating atherosclerosis.
Oral Infection With a Periodontal Pathogen Accelerates Early Atherosclerosis in Apolipoprotein E–Null Mice
Authors: Lalla Evanthia , Lamster Ira B. , Hofmann Marion A. , Bucciarelli Loredana , Jerud Adrienne P. , Tucker Sid , Lu Yan , Papapanou Panos N. , Schmidt Ann Marie 
Published: June 2003

Objective—Because recent epidemiologic evidence suggests that periodontal infections may increase the risk of atherosclerosis and related events in humans, we assessed the impact of oral inoculation with the periodontal pathogenPorphyromonas gingivalison atherogenesis in hypercholesterolemic apolipoprotein E–null mice.Methods and Results—In the absence of alterations in distinct risk factors,P gingivalisinfection exacerbated the early stages of atherogenesis in this model. Infected animals displayed evidence of local periodontal infection, as the severity of alveolar bone loss, the hallmark of periodontitis, was increased. Generalized activation of host inflammatory responses was evident in infected mice, as demonstrated by serum IgG response toP gingivalisand elevated levels of interleukin-6.P gingivalisDNA was localized in the aortic tissue from a limited number of infected mice but not in any noninfected controls. Infected mice displayed enhanced vascular activation, as suggested by increased aortic expression of vascular cell adhesion molecule-1 and tissue factor.Conclusions—Oral infection withP gingivalisaccelerates early atherosclerosis. Thus, uncovering the underlying mechanisms is critical for the design of preventive and therapeutic strategies targeting atherosclerotic vascular disease and its sequelae.
Dominant Expression of the CysLT2Receptor Accounts for Calcium Signaling by Cysteinyl Leukotrienes in Human Umbilical Vein Endothelial Cells
Authors: Sjöström Mattias , Johansson Anne-Sofie , Schröder Oliver , Qiu Hong , Palmblad Jan , Haeggström Jesper Z. 
Published: June 2003

Objective—The objective of the present study was to identify and characterize the cell-surface receptors on human umbilical vein endothelial cells (HUVECs) that transduce calcium transients elicited by cysteinyl leukotrienes (CysLTs), potent spasmogenic and proinflammatory agents with profound effects on the cardiovascular system.Methods and Results—Using quantitative reverse transcription–polymerase chain reaction, we found that HUVECs abundantly express CysLT2R mRNA in vast excess (>4000-fold) of CysLT1R mRNA. Lipopolysaccharide, tumor necrosis factor-α, or interleukin-1β caused a rapid (within 30 minutes) and partially reversible suppression of CysLT2R mRNA levels. Challenge of HUVECs with BAY u9773, a specific CysLT2R agonist, triggered diagnostic Ca2+transients. LTC4and LTD4are equipotent agonists, and their actions can be blocked by the dual-receptor antagonist BAY u9773, but not by the CysLT1R-selective antagonist MK571.Conclusions—HUVECs almost exclusively express the CysLT2R. Furthermore, Ca2+fluxes elicited by CysLT in these cells emanate from perturbation of the CysLT2R, rather than the expected CysLT1R. Hence, signaling events involving CysLT2R might trigger functional responses involved in the critical components of LT-dependant vascular reactions, which in turn have implications for ischemic heart disease and myocardial infarction.
Can Information and Communication Technology Solve Japan's Productivity Slowdown Problem?
Authors: Nishimura Kiyohiko G. , Shirai Masato 
Published: June 2003

This paper has three parts. First, we compile a new industry-by-industry data set of the Japanese economy in which information and communication technology (ICT) stocks are explicitly estimated and labor inputs are disaggregated with respect to age and education. Second, we investigate the effect of ICT on various labor inputs and discern for which labor inputs ICT is able to substitute. Third, we estimate the contribution of capital stocks, including ICT, and various labor inputs to the value-added growth of the Japanese economy in the 1980s and 1990s and explore the factors that determine technological progress. We find ICT capital stocks are an important substitute for young workers with low education levels. These results strongly suggest that ICT investment is an effective way to counter the prospective shortage of young workers in Japan. In contrast, we find no compelling evidence of productivity-enhancing ICT externality. On the contrary, our results suggest that ICT has a negative indirect effect on productivity. The past technological and managerial strengths of Japanese firms, which have been based on workers' learning by doing in the workplace, may no longer be advantages as knowledge management systems improve and become easily transferred across international borders.
Intra- to Multidecadal Climate Variability over the Continental United States: 1932–99
Authors: Mauget Steven A. 
Published: June 2003

Abstract
Trend analysis is used frequently in climate studies, but it is vulnerable to a number of conceptual shortcomings. This analysis of U.S. climate division data uses an alternate approach. The method used here subjects time series of annual average temperature and total precipitation to tests of Mann–Whitney U statistics over moving sampling windows of intra- to multidecadal (IMD) duration. In applying this method to time series of nationally averaged annual rainfall, a highly significant incidence of wet years is found after the early 1970s. When applied to individual climate divisions this test provides the basis for a climate survey method that is more robust than linear trend analysis, and capable of objectively isolating the timing and location of major IMD climate events over the United States. From this survey, four such periods emerge between 1932 and 1999: the droughts of the 1930s and 1950s, a cool 1964–79 period, and wet–warm time windows at the end of the century. More circumstantial consideration was also given here to the state of ENSO, the Pacific decadal oscillation (PDO), the winter state of the North Atlantic Oscillation, and mean annual Northern Hemisphere surface temperature during those periods. Anecdotal evidence presented here suggests that wet years associated with warm-phase ENSO conditions and the positive phase of the PDO may have played a role in ending the drought periods of the 1930s and 1950s. Conversely, the La Niña–like climate impacts found here during the late 1940s to mid-1950s, and the increased incidence of cold phase ENSO and negative phase PDO conditions during that time, suggests connections between that ocean state and severe drought. Significant late-century warmth was found mainly in the western United States after the mid-1980s, but no evidence of a cooling trend was evident in the southeast, as reported elsewhere. The late-century wet regime appears to have occurred in two phases, with wetness confined to the east during 1972–79, and more concentrated in the southwest and central United States during 1982–99.