bluuebunny/crossref_metadata_2025_split huggingface dataset:
Monotherapy with Intravenous Followed by Oral High-Dose Ciprofloxacin versus Combination Therapy with Ceftazidime plus Amikacin as Initial Empiric Therapy for Granulocytopenic Patients with Fever
Authors: Giamarellou Helen , Bassaris Harry P. , Petrikkos George , Busch Wilhelm , Voulgarelis Michel , Antoniadou Anastasia , Grouzi Elisabeth , Zoumbos Nikolaos 
Published: July 2002

ABSTRACT

The aim of the present study was to obtain clinical experience with the use of high-dose ciprofloxacin as monotherapy for the treatment of febrile neutropenia episodes (granulocyte count, <500/mm
3
) compared to a standard regimen and to clarify whether ciprofloxacin administration may be switched to the oral route. In a prospective randomized study ciprofloxacin was given at 400 mg three times a day (t.i.d.) for at least 72 h followed by oral administration at 750 mg twice a day (b.i.d). That regimen was compared with ceftazidime given intravenously at 2 g t.i.d. plus amikacin given intravenously at 500 mg b.i.d. The frequency of successful clinical response without modification at the end of therapy was almost identical for ciprofloxacin (50% [62 of 124 patients]) compared with that for ceftazidime plus amikacin (50.8% [62 of 122 patients]) in an intent-to-treat analysis; the frequencies were 48.3% (57 of 118 patients) versus 49.6% (56 of 113 patients), respectively, in a per-protocol analysis (
P
values for one-sided equivalence, 0.0485 and 0.0516, respectively; δ = 10%), with no significant differences among patients with bacteremia and other microbiologically or clinically documented infections and fever of unknown origin. For 82 (66.1%) patients, it was possible to switch from parenteral ciprofloxacin to the oral ciprofloxacin, and the response was successful for 61 (74.4%) patients. The efficacies of the regimens against streptococcal bacteremias were 16.6% (one of six patients) for the ciprofloxacin group and 33.3% (one of three patients) for the combination group (it was not statistically significant), with one breakthrough streptococcal bacteremia observed among the ciprofloxacin-treated patients. Adverse events were mostly self-limited and were observed in 27 (20.6%) ciprofloxacin-treated patients and 26 (19.7%) patients who were receiving the combination. This study demonstrates that high-dose ciprofloxacin given intravenously for at least 3 days and then by the oral route is therapeutically equivalent to the routine regimen of intraveneous ceftazidime plus amikacin even in febrile patients with severe neutropenia (polymorphonuclear leukocyte count, <100 mm
3
). However, it is very important that before an empirical therapy is chosen each hospital determine bacteriologic predominance and perform resistance surveillance.
Susceptibilities of Human Cytomegalovirus Clinical Isolates to BAY38-4766, BAY43-9695, and Ganciclovir
Authors: McSharry James J. , McDonough Ann , Olson Betty , Hallenberger Sabine , Reefschlaeger Juergen , Bender Wolfgang , Drusano George L. 
Published: July 2002

ABSTRACT
BAY38-4766 and BAY43-9695 are nonnucleosidic compounds with activities against human cytomegalovirus (HCMV). Two phenotypic assays were used to determine the drug susceptibilities of 36 HCMV clinical isolates to the BAY compounds and ganciclovir. Using either assay, both BAY compounds at a concentration of approximately 1 μM inhibited the replication of all 36 HCMV clinical isolates, including 11 ganciclovir-resistant clinical isolates, by 50%.
High Prevalence of Inducible Erythromycin Resistance among
Streptococcus bovis
Isolates in Taiwan
Authors: Teng Lee-Jene , Hsueh Po-Ren , Ho Shen-Wu , Luh Kwen-Tay 
Published: July 2002

ABSTRACT

Susceptibilities to 13 antimicrobial agents were determined by measurement of MICs for 60 isolates of
Streptococcus bovis
from blood cultures. Thirty-eight isolates (63.3%) had high-level resistance to erythromycin (MICs, ≥128 μg/ml). Among the 38 erythromycin-resistant strains, 21 isolates (55%) had inducible resistance to macrolides-lincosamides-streptogramin B (iMLS isolates) and 17 (45%) had constitutive resistance to macrolides-lincosamides-streptogramin B (cMLS isolates). Tetracycline resistance was also found among all of the erythromycin-resistant strains. None of the strains displayed resistance to penicillin, chloramphenicol, or vancomycin. Detection of erythromycin resistance genes by PCR and sequencing indicated that all 17 cMLS isolates were positive for the
ermB
gene and that 7 of 21 iMLS isolates carried the
ermB
gene and the remaining 14 iMLS isolates carried the
ermT
gene. Sequence analysis of amplified partial
ermB
fragments (594 bp) from
S. bovis
isolates revealed a 99.8% nucleotide identity and a 100% amino acid homology compared with the sequences from gene banks. The sequences of amplified fragments with primers targeted for
ermC
were shown to be very similar to that of
ermGT
(
ermT
) from
Lactobacillus reuteri
(98.5% nucleotide identity). This is the first report to describe the detection of the
ermT
class of erythromycin resistance determinants in
S. bovis
. The high rate of inducible erythromycin resistance among
S. bovis
isolates in Taiwan was not reported before. The iMLS
S. bovis
isolates were shown to be heterogeneous by randomly amplified polymorphic DNA analysis. These results indicate that the prevalence of inducible erythromycin resistance in
S. bovis
in Taiwan is very high and that most of the resistant strains carry the
ermT
or the
ermB
gene.
In Vitro Activities of Approved and Investigational Antifungal Agents against 44 Clinical Isolates of Basidiomycetous Fungi
Authors: González Gloria M. , Sutton Deanna A. , Thompson Elizabeth , Tijerina Rolando , Rinaldi Michael G. 
Published: July 2002

ABSTRACT

The in vitro activity of amphotericin B, fluconazole, flucytosine, itraconazole, voriconazole, and posaconazole was evaluated against 44 clinical isolates of filamentous basidiomycetous fungi. No statistically significant differences were noted between
Schizophyllum commune
(
n
= 5),
Coprinus
species (
n
= 8),
Bjerkandera adusta
(
n
= 14), and sterile, uncharacterized basidiomycetes (
n
= 17).
Interspecies Recombination Contributes Minimally to Fluoroquinolone Resistance in
Streptococcus pneumoniae
Authors: Bast Darrin J. , de Azavedo Joyce C. S. , Tam Tiffany Y. , Kilburn Laurie , Duncan Carla , Mandell Lionel A. , Davidson Ross J. , Low Donald E. 
Published: July 2002

ABSTRACT

Analysis of 71 ciprofloxacin-resistant (MIC ≥ 4 μg/ml)
Streptococcus pneumoniae
clinical isolates revealed only 1 for which the quinolone resistance-determining regions of the
parC
,
parE
, and
gyrB
genes were genetically related to those of viridans group streptococci. Our findings support the occurrence of interspecies recombination of type II topoisomerase genes; however, its contribution to the emergence of quinolone resistance among pneumococci appears to have been minimal.
Initial Colonization, Nutrient Supply, and Fungal Activity on Leaves Decaying in Streams
Authors: Sridhar K. R. , Bärlocher Felix 
Published: July 2002

ABSTRACT
Aquatic hyphomycetes dominate leaf decomposition in streams, and their biomass is an important component in the diet of leaf-eating invertebrates. After 2 weeks of exposure in a first-order stream, maple leaf disks had low levels of fungal biomass and species diversity. Spore production by aquatic hyphomycetes also was low. Subsets of these disks were left in the stream for another 3 weeks or incubated in defined mineral solutions with one of three levels of nitrate and phosphate. Stream disks lost mass, increased ergosterol levels and spore production, and were colonized by additional fungal species. External N and P significantly stimulated mass loss, ergosterol accumulation, and spore production of laboratory disks. On disks incubated without added N and P, ergosterol levels declined while conidium production continued, suggesting conversion of existing hyphal biomass to propagules. In all other treatments, approximately equal amounts of newly synthesized biomass were invested in hyphae and conidia. Net yield (fungal biomass per leaf mass lost) varied between 1% (in the laboratory, without added N or P) and 31% (decay in stream). In most treatments, the three aquatic hyphomycete species that dominated spore production during the first 2 weeks in the stream also produced the largest numbers of conidia in the following 3 weeks. Principal-component analysis suggested two divergent trends from the initial fungal community established after 2 weeks in the stream. One culminated in the community of the second phase of stream exposure, and the other culminated in the laboratory treatment with the highest levels of N and P. The results suggest that fungal production in streams, and, by extension, production of invertebrates and higher tropic levels, is stimulated by inorganic N and P.
Simple and Efficient Method for Heterologous Expression of Clostridial Proteins
Authors: Zdanovsky Alexey G. , Zdanovskaia Marina V. 
Published: July 2002

ABSTRACT

Many clostridial proteins are poorly produced in
Escherichia coli
. It has been suggested that this phenomena is due to the fact that several types of codons common in clostridial coding sequences are rarely used in
E. coli
and the quantities of the corresponding tRNAs in
E. coli
are not sufficient to ensure efficient translation of the corresponding clostridial sequences. To address this issue, we amplified three
E. coli
genes,
ileX
,
argU
, and
leuW
, in
E. coli
; these genes encode tRNAs that are rarely used in
E. coli
(the tRNAs for the ATA, AGA, and CTA codons, respectively). Our data demonstrate that amplification of
ileX
dramatically increased the level of production of most of the clostridial proteins tested, while amplification of
argU
had a moderate effect and amplification of
leuW
had no effect. Thus, amplification of certain tRNA genes for rare codons in
E. coli
improves the expression of clostridial genes in
E. coli
, while amplification of other tRNAs for rare codons might not be needed for improved expression. We also show that amplification of a particular tRNA gene might have different effects on the level of protein production depending on the prevalence and relative positions of the corresponding codons in the coding sequence. Finally, we describe a novel approach for improving expression of recombinant clostridial proteins that are usually expressed at a very low level in
E. coli
.
Evidence for Detachment of Indigenous Bacteria from Aquifer Sediment in Response to Arrival of Injected Bacteria
Authors: Johnson W. P. , Zhang P. , Gardner P. M. , Fuller M. E. , DeFlaun M. F. 
Published: July 2002

ABSTRACT
Two bacterial strains isolated from the aquifer underlying Oyster, Va., were recently injected into the aquifer and monitored using ferrographic capture, a high-resolution immunomagnetic technique. Injected cells were enumerated on the basis of a vital fluorescence stain, whereas total cell numbers (stained target cells plus unstained target and antigenically similar indigenous bacteria) were identified by cell outlines emanating from fluorophore-conjugated antibodies to the two target strains. The arrival of injected bacteria at the majority of monitored sampling ports was accompanied by simultaneous temporary increases in unstained cell counts that outnumbered the injected bacteria by 2- to 100-fold. The origin and mechanism of appearance of the unstained cells are considered.
Comparison of Extracellular Enzyme Activities and Community Composition of Attached and Free-Living Bacteria in Porous Medium Columns
Authors: Lehman R. Michael , O'Connell Seán P. 
Published: July 2002

ABSTRACT

Free-living and surface-associated microbial communities in sand-packed columns perfused with groundwater were compared by examination of compositional and functional characteristics. The composition of the microbial communities was assessed by bulk DNA extraction, PCR amplification of 16S ribosomal DNA fragments, separation of these fragments by denaturing gradient gel electrophoresis, and sequence analysis. Community function was assessed by measurement of β-glucosidase and aminopeptidase extracellular enzyme activities. Free-living populations in the aqueous phase exhibited a greater diversity of phylotypes than populations associated with the solid phase. The attached bacterial community displayed significantly greater β-glucosidase and aminopeptidase enzyme activities per volume of porous medium than those of the free-living community. On a per-cell basis, the attached community had a significantly higher cell-specific aminopeptidase enzyme activity (1.07 × 10
−7
nmol cell
−1
h
−1
) than the free-living community (5.02 × 10
−8
nmol cell
−1
h
−1
). Conversely, the free-living community had a significantly higher cell-specific β-glucosidase activity (1.92 × 10
−6
nmol cell
−1
h
−1
) than the surface-associated community (6.08 × 10
−7
nmol cell
−1
h
−1
). The compositional and functional differences observed between these two communities may reflect different roles for these distinct but interacting communities in the decomposition of natural organic matter or biodegradation of xenobiotics in aquifers.
ALimulusAntilipopolysaccharide Factor-Derived Peptide Exhibits a New Immunological Activity with Potential Applicability in Infectious Diseases
Authors: Vallespi Maribel G. , Glaria Luis A. , Reyes Osvaldo , Garay Hilda E. , Ferrero Joel , Araña Manuel J. 
Published: July 2002

ABSTRACTPrevious studies have shown that cyclic peptides corresponding to residues 35 to 52 of theLimulusantilipopolysaccharide (anti-LPS) factor (LALF) bind and neutralize LPS-mediated in vitro and in vivo activities. Therapeutic approaches based on agents which bind and neutralize LPS activities are particularly attractive because these substances directly block the primary stimulus for the entire proinflammatory cytokine cascade. Here we describe new activities of the LALF31–52peptide, other than its LPS binding ability. Surprisingly, supernatants from human mononuclear cells stimulated with the LALF peptide are able to induce in vitro antiviral effects on the Hep-2 cell line mediated by gamma interferon (IFN-γ) and IFN-α. Analysis of the effect of LALF31–52on tumor necrosis factor (TNF) and nitric oxide (NO) production by LPS-stimulated peritoneal macrophages revealed that a pretreatment with the peptide decreased LPS-induced TNF production but did not affect NO generation. This indicates that the LALF peptide modifies the LPS-induced response. In a model in mice with peritoneal fulminating sepsis, LALF31–52protected the mice when administered prophylactically, and this effect is related to reduced systemic TNF-α levels. This study demonstrates, for the first time, the anti-inflammatory properties of the LALF-derived peptide. These properties widen the spectrum of the therapeutic potential for this LALF-derived peptide and the molecules derived from it. These agents may be useful in the prophylaxis and therapy of viral and bacterial infectious diseases, as well as for septic shock.
Slow Human Immunodeficiency Virus (HIV) Infectivity Correlated with Low HIV Coreceptor Levels
Authors: Bristow Cynthia L. 
Published: July 2002

ABSTRACT

The absolute number of CD4
+
lymphocytes in blood is prognostic for disease progression, yet the cell surface density of CD4 receptors or chemokine receptors on a single cell has not previously been found to be predictive of human immunodeficiency virus (HIV) infectivity outcome. It has recently been shown that human leukocyte elastase (HLE) and its ligand α
1
proteinase inhibitor (α
1
PI; α
1
antitrypsin) act as HIV fusion cofactors. The present study shows that decreased HIV infectivity is significantly correlated with decreased cell surface density of HLE but not with decreased CD4 nor chemokine receptors. In vitro HIV infectivity outcome in this study was predicted by the surface density of HLE on mononuclear phagocytes but not on lymphocytes. The set point HLE surface density was in part determined by α
1
PI. Decreased circulating α
1
PI was correlated with increased cell surface HLE and with increased HIV infectivity. The correlation of HIV infectivity outcome with surface HLE and circulating α
1
PI supports the utility of these HIV cofactors in diagnostic analysis and therapeutic intervention.
Surface Immobilization Antigen of the Parasitic Ciliate
Ichthyophthirius multifiliis
Elicits Protective Immunity in Channel Catfish (
Ictalurus punctatus
)
Authors: Wang Xuting , Dickerson Harry W. 
Published: July 2002

ABSTRACT

Channel catfish (
Ictalurus punctatus
) that survive infection with the parasitic ciliate
Ichthyophthirius multifiliis
acquire immunity to subsequent challenge and produce specific antibodies in serum that immobilize the parasite in vitro. Cellular surface protein antigens targeted by these antibodies are referred to as immobilization antigens (i-antigens). By using an immobilizing mouse monoclonal antibody as a ligand, the i-antigen of
I. multifiliis
isolate G5 was purified to homogeneity by immunoaffinity chromatography, and its immunogenicity was confirmed by inoculating rabbit and channel catfish to produce immobilizing antisera. To test the purified i-antigen as a subunit vaccine, channel catfish fingerlings were injected intraperitoneally (i.p.) with purified i-antigen at a dose of 10 μg/fish in complete Freund’s adjuvant on day 1, followed by a second i.p. injection of the same amount of i-antigen in incomplete Freund’s adjuvant on day 15. Negative control fish were immunized similarly with either bovine serum albumin (BSA) or an immobilization-irrelevant
I. multifiliis
protein. On day 84, the fish were challenged with live
I. multifiliis
G5 theronts at a dose of 15,000 cells per fish. Seventy-two percent of the fish immunized with i-antigen survived the challenge. All negative control fish died within 16 days of exposure. There was a significant difference in the median days to death between the negative control fish injected with BSA and the fish that died following vaccination with i-antigen. Fish injected with i-antigen developed high immobilizing antibody titers in serum. This is the first demonstration of a direct role for i-antigens in the elicitation of protective immunity, suggesting that these proteins by themselves serve as effective subunit vaccines against
I. multifiliis.
Mutants ofListeria monocytogenesDefective in In Vitro Invasion and Cell-to-Cell Spreading Still Invade and Proliferate in Hepatocytes of Neutropenic Mice
Authors: Appelberg Rui , Leal Irene S. 
Published: July 2002

ABSTRACTListeria monocytogenesmutants defective in theactAgene, theplcBgene, and theinlAandinlBgenes were less virulent when injected intravenously into BALB/c mice. The growth of these strains as well as of the virulent wild-type strains was increased by treating mice with a neutrophil-specific depleting monoclonal antibody, RB6-8C5. Histologic examination of the livers of the treated animals showed intrahepatocytic proliferation of the listeriae in all cases. Our data show that more than one pathway exists that allowsL. monocytogenesto invade parenchymal cells. One pathway most likely involves theactAandplcBgene products, and a second one probably involves the internalins.
Epitope Mapping of the Outer Membrane Protein P5-Homologous Fimbrin Adhesin of Nontypeable
Haemophilus influenzae
Authors: Novotny Laura A. , Jurcisek Joseph A. , Pichichero Michael E. , Bakaletz Lauren O. 
Published: July 2002

ABSTRACT

To identify potential immunodominant and/or adhesin binding domains of the outer membrane protein P5-homologous fimbrin adhesin of nontypeable
Haemophilus influenzae
(NTHI), three sets of synthetic peptides were synthesized and assayed in an adherence inhibition assay, by Western blotting, and in a biomolecular interaction analysis (BIA) system. The first series of 34 8- to 10-mer peptides represented the entire mature protein sequentially. The second set of four peptides (each 19 to 28 residues) represented the four predicted major surface-exposed regions (or loops) of this adhesin. The third series of seven peptides (each 27 to 34 residues) were specifically designed to map the third surface-exposed region. Data obtained by BIA indicated limited reactivity of a panel of high-titered immune chinchilla sera to the 8- to 10-mer peptides representing the mature protein, likely because these linear peptides did not represent continuous epitopes. However, several of these short peptides did inhibit adherence of multiple NTHI strains to a human respiratory epithelial cell. Overall, greatest relative reactivity in both BIA and adherence inhibition assays was demonstrated against, or shown by, peptides mapping to the third and fourth predicted surface-exposed regions of this adhesin, thereby indicating the presence of immunodominant and adhesin binding domains at these sites. Middle ear fluids sequentially recovered from a chinchilla with an ongoing NTHI-induced otitis media (OM) as well as sera from children with OM due to NTHI also reacted exclusively with peptides representing the third and fourth surface-exposed regions of the P5-fimbrin adhesin, indicating a similarity in immune recognition of this bacterial protein by these two hosts. Collectively, these data together with the previously demonstrated protective efficacy of immunogens derived from this adhesin in chinchilla models support the continued development of P5-fimbrin based vaccine components.
Inhibition of Vesicular Secretion in Both Neuronal and Nonneuronal Cells by a Retargeted Endopeptidase Derivative of
Clostridium botulinum
Neurotoxin Type A
Authors: Chaddock John A. , Purkiss John R. , Friis Lorna M. , Broadbridge Janice D. , Duggan Michael J. , Fooks Sarah J. , Shone Clifford C. , Quinn Conrad P. , Foster Keith A. 
Published: July 2002

ABSTRACT

Clostridial neurotoxins potently and specifically inhibit neurotransmitter release in defined cell types by a mechanism that involves cleavage of specific components of the vesicle docking/fusion complex, the SNARE complex. A derivative of the type A neurotoxin from
Clostridium botulinum
(termed LH
N
/A) that retains catalytic activity can be prepared by proteolysis. The LH
N
/A, however, lacks the putative native binding domain (H
C
) of the neurotoxin and is thus unable to bind to neurons and effect inhibition of neurotransmitter release. Here we report the chemical conjugation of LH
N
/A to an alternative cell-binding ligand, wheat germ agglutinin (WGA). When applied to a variety of cell lines, including those that are ordinarily resistant to the effects of neurotoxin, WGA-LH
N
/A conjugate potently inhibits secretory responses in those cells. Inhibition of release is demonstrated to be ligand mediated and dose dependent and to occur via a mechanism involving endopeptidase-dependent cleavage of the natural botulinum neurotoxin type A substrate. These data confirm that the function of the H
C
domain of
C. botulinum
neurotoxin type A is limited to binding to cell surface moieties. The data also demonstrate that the endopeptidase and translocation functions of the neurotoxin are effective in a range of cell types, including those of nonneuronal origin. These observations lead to the conclusion that a clostridial endopeptidase conjugate that can be used to investigate SNARE-mediated processes in a variety of cells has been successfully generated.