bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transgenic and gene targeting studies of hair cell function in mouse inner ear
Authors: Zuo Jian 
Published: October 2002

AbstractDespite the rapid discovery of a large number of genes in sensory hair cells of the inner ear, the functional roles of these genes in hair cells remain largely undetermined. Recent advances in transgenic and gene targeting technologies in mice have offered unprecedented opportunities to genetically manipulate the expression of these genes and to study their functional roles in hair cellsin vivo. Transgenic analyses have revealed the presence of hair‐cell–specific promoters in the genes encoding Math1, myosin VIIa, Pou4f3, and the α9 subunit of the acetylcholine receptor (α9 AChR). Targeted inactivation using embryonic stem cell technology and transgenic expression studies have revealed the roles of several genes involved in hair cell lineage (Math1), differentiation (Pou4f3), mechanotransduction (Myo1c,andMyo7a), electromotility (Prestin), and efferent modulation (Chrna9, encoding α9 AChR). Although many of these genes also play roles in other tissues, inactivation of these genes in hair cells alone will soon be possible by using the Cre–loxPsystem. Also imminent is the development of genetic methods to inactivate genes specifically in mouse hair cells at a desired time, by using inducible systems established in other types of neurons. Combining these types of manipulation of gene expression will enable hearing researchers to elucidate some of the fundamental and unique features of hair cell function such as mechanotransduction, frequency tuning, active mechanical amplification, and efferent modulation. © 2002 Wiley Periodicals, Inc. J Neurobiol 53: 286–305, 2002
Electroejaculation and semen analysis in the La Plata three‐banded armadillo (Tolypeutes matacus)
Authors: Herrick J.R. , Campbell M.K. , Swanson W.F. 
Published: October 2002

AbstractThe objectives of this study were to: 1) develop an electroejaculation procedure for collecting semen from the La Plata three‐banded armadillo (Tolypeutes matacus), and 2) characterize basal reproductive traits, including sperm concentration, motility, morphology, acrosomal status, and viability. Three male armadillos were each electroejaculated on one to five occasions. Fluid containing spermatozoa was recovered during each attempt, and high proportions (>75%) of morphologically normal spermatozoa were seen in all analyzed samples. Two fluorescent stains (FITC‐PNA and Hoechst 33258) appeared to be effective for assessing acrosomal status and viability, respectively, in this species. Sperm concentration and motility were usually low, and urine contamination was a persistent problem—possibly due to anesthesia, unique reproductive anatomy, and/or improper probe placement. Poor sperm recovery, urine contamination, and sensitivity of spermatozoa to culture medium must be addressed before electroejaculation can be used routinely in the La Plata three‐banded armadillo. Zoo Biol 21:481–487, 2002. © 2002 Wiley‐Liss, Inc.
Importance of the wasting syndrome complex in captive moose (Alces alces)
Authors: Clauss Marcus , Kienzle Ellen , Wiesner Henning 
Published: October 2002

AbstractWe conducted a survey on the causes of moose (Alces alces) deaths at 19 European moose facilities. The age at death was recorded for 205 moose, and the cause of death for 131 adult animals. The “wasting syndrome complex” (WSC) [Shochat et al., 1997] was the single most important mortality factor in adult animals, being responsible for 47% of all cases. Other important factors were intraspecific aggression (13%) and malignant catarrhal fever (12%). The number of deaths showed a peak at the age of 6–8 years. A similar peak was found in the age distribution of WSC cases only, suggesting an accumulative process that leads to the death of an animal once a threshold is reached. While the dominance of WSC is in accord with the American literature, the high incidence of intraspecific aggression found in this and other European surveys is not reported in North America. While in the North American literature the consumption of grass and grass products is regarded as the main factor triggering WSC, infection with whipworms (Trichuris spp.) and continuous reinfection through pasture grazing is emphasized as the main danger in Europe. Most reports of WSC in the literature concern animals that grazed in pasture‐like enclosures. In no case was WSC triggered by controlled feeding of freshly cut grass fed to animals in holding pens. In our survey, in half of all documented WSC cases Trichuris infestation was reported as well. With a high proportion of incomplete necropsies in our data set, we suggest that the contribution of Trichuris to the problems of moose husbandry has been underestimated. Zoo Biol 21:499–506, 2002. © 2002 Wiley‐Liss, Inc.
Development of alcohol-associated cues and cue-induced brain activation in alcoholics
Authors: Wrase J. , Grüsser S.M. , Klein S. , Diener C. , Hermann D. , Flor H. , Mann K. , Braus D.F. , Heinz A. 
Published: October 2002

SummaryThe objective of this study was to develop new standardized alcohol-associated cues and assess their effects on brain activation with functional magnetic resonance imaging (fMRI). Pictures of alcoholic and neutral beverages and affectively neutral pictures were presented to 44 abstinent alcoholics and 37 age-matched healthy control subjects. We assessed the skin conductance response, and the elicited arousal and valence. Alcoholics and control subjects did not differ in arousal, valence or skin conductance response evoked by alcohol-associated and affectively neutral stimuli, while nonalcoholic beverages were rated as more unpleasant and arousing by alcoholics compared with control subjects. In the fMRI pilot study, alcohol and abstract pictures were presented to six abstinent alcoholics and induced a significant activation of brain areas associated with visual emotional processes such as the fusiform gyrus, parts of the brain reward system (basal ganglia and orbitofrontal gyrus) and further brain regions in the frontal and parietal cortices associated with the attention network. These observations suggest that standardized pictures of alcoholic beverages can be used to assess brain circuits involved in the processing and evaluation of alcohol cues.
Self-esteem, social adjustment and suicidality in affective disorders
Authors: Daskalopoulou E.G. , Dikeos D.G. , Papadimitriou G.N. , Souery D. , Blairy S. , Massat I. , Mendlewicz J. , Stefanis C.N. 
Published: October 2002

SummarySelf-esteem (SE) and social adjustment (SA) are often impaired during the course of affective disorders; this impairment is associated with suicidal behaviour. The aim of the present study was to investigate SE and SA in unipolar or bipolar patients in relation to demographic and clinical characteristics, especially the presence of suicidality (ideation and/or attempt). Forty-four patients, 28 bipolar and 16 unipolar, in remission for at least 3 months, and 50 healthy individuals were examined through a structured clinical interview. SE and SA were assessed by the Rosenberg self-esteem scale and the social adjustment scale, respectively. The results have shown that bipolar patients did not differ from controls in terms of SE, while unipolar patients had lower SE than bipolars and controls. No significant differences in the mean SA scores were found between the three groups. Suicidality during depression was associated only in bipolar patients with lower SE at remission; similar but not as pronounced was the association of suicidality with SA. It is concluded that low SE lasting into remission seems to be related to the expression of suicidality during depressive episodes of bipolar patients, while no similar pattern is evident in unipolar patients.
Defining and Combating the Mechanisms of Triclosan Resistance in Clinical Isolates ofStaphylococcus aureus
Authors: Fan Frank , Yan Kang , Wallis Nicola G. , Reed Shannon , Moore Terrance D. , Rittenhouse Stephen F. , DeWolf Walter E. , Huang Jianzhong , McDevitt Damien , Miller William H. , Seefeld Mark A. , Newlander Kenneth A. , Jakas Dalia R. , Head Martha S. , Payne David J. 
Published: October 2002

ABSTRACTThe MICs of triclosan for 31 clinical isolates ofStaphylococcus aureuswere 0.016 μg/ml (24 strains), 1 to 2 μg/ml (6 strains), and 0.25 μg/ml (1 strain). All the strains for which triclosan MICs were elevated (>0.016 μg/ml) showed three- to fivefold increases in their levels of enoyl-acyl carrier protein (ACP) reductase (FabI) production. Furthermore, strains for which triclosan MICs were 1 to 2 μg/ml overexpressed FabI with an F204C alteration. Binding studies with radiolabeled NAD+demonstrated that this change prevents the formation of the stable triclosan-NAD+-FabI complex, and both this alteration and its overexpression contributed to achieving MICs of 1 to 2 μg/ml for these strains. Three novel, potent inhibitors of FabI (50% inhibitory concentrations, ≤64 nM) demonstrated up to 1,000-fold better activity than triclosan against the strains for which triclosan MICs were elevated. None of the compounds tested from this series formed a stable complex with NAD+-FabI. Consequently, although the overexpression of wild-type FabI gave rise to an increase in the MICs, as expected, overexpression of FabI with an F204C alteration did not cause an additional increase in resistance. Therefore, this work identifies the mechanisms of triclosan resistance inS. aureus, and we present three compounds from a novel chemical series of FabI inhibitors which have excellent activities against both triclosan-resistant and -sensitive clinical isolates ofS. aureus.
Constitutive High Expression of Chromosomal β-Lactamase in
Pseudomonas aeruginosa
Caused by a New Insertion Sequence (IS
1669
) Located in
ampD
Authors: Bagge Niels , Ciofu Oana , Hentzer Morten , Campbell Joan I. A. , Givskov Michael , Høiby Niels 
Published: October 2002

ABSTRACT

The expression of chromosomal AmpC β-lactamase in
Pseudomonas aeruginosa
is negatively regulated by the activity of an amidase, AmpD. In the present study we examined resistant clinical
P. aeruginosa
strains and several resistant variants isolated from in vivo and in vitro biofilms for mutations in
ampD
to find evidence for the genetic changes leading to high-level expression of chromosomal β-lactamase. A new insertion sequence, IS
1669
, was found located in the
ampD
genes of two clinical
P. aeruginosa
isolates and several biofilm-isolated variants. The presence of IS
1669
in
ampD
resulted in the expression of high levels of AmpC β-lactamase. Complementation of these isolates with
ampD
from the reference
P. aeruginosa
strain PAO1 caused a dramatic decrease in the expression of AmpC β-lactamase and a parallel decrease of the MIC of ceftazidime to a level comparable to that of PAO1. One highly resistant, constitutive β-lactamase-producing variant contained no mutations in
ampD
, but a point mutation was observed in
ampR
, resulting in an Asp-135→Asn change. An identical mutation of AmpR in
Enterobacter cloacae
has been reported to cause a 450-fold higher AmpC expression. However, in many of the isolates expressing high levels of chromosomal β-lactamase, no changes were found in either
ampD
,
ampR
, or in the promoter region of
ampD
,
ampR
, or
ampC
. Our results suggest that multiple pathways may exist leading to increased antimicrobial resistance due to chromosomal β-lactamase.
Resistance to β-Lactamase Inhibitor Protein Does Not Parallel Resistance to Clavulanic Acid in TEM β-Lactamase Mutants
Authors: Schroeder William A. , Locke Troy R. , Jensen Susan E. 
Published: October 2002

ABSTRACT
In order to compare patterns of resistance to inhibition by clavulanic acid with patterns of resistance to inhibition by a β-lactamase inhibitor protein (BLIP), R164S, R244S, and R164S/R244S mutant forms of TEM β-lactamase were prepared by site-directed mutagenesis. When kinetic parameters were determined for these mutant and wild-type forms of TEM, the single mutants showed properties that were similar to those in the literature but the double mutant showed properties that were very different. The R164S/R244S double mutant form of TEM retained its resistance to inhibition by clavulanic acid (characteristic of the R244S mutation) but lost all its ability to hydrolyze ceftazidime (characteristic of the R164S mutation). While these characteristics are contrary to those previously reported for an R164S/R244S double mutant, this discrepancy resulted from the use of a defective mutant in the earlier study. Both the single and double mutant forms of TEM remained highly sensitive when tested for inhibition by BLIP, showing only slightly increased resistance compared to that of the wild type; this pattern of resistance is quite different from the pattern of clavulanic acid resistance. The slight increases in resistance to inhibition by BLIP seen in the mutants may have been related to the fact that all of the mutations effected changes in the net charge on the TEM protein that could impede interactions with BLIP.
Determination of Antibiotic Effect in an In Vitro Pharmacodynamic Model: Comparison with an Established Animal Model of Infection
Authors: Bonapace Charles R. , Friedrich Lawrence V. , Bosso John A. , White Roger L. 
Published: October 2002

ABSTRACT

Animal infection models have historically been used to study pharmacodynamic relationships. Similar results could theoretically be produced by using an in vitro pharmacodynamic model as an alternative to animal models. We compared the antibiotic effects of ticarcillin administered in various doses and dosing regimens against
Pseudomonas aeruginosa
ATCC 27853 under conditions analogous to those previously employed in a neutropenic-mouse thigh infection model (B. Vogelman et al., J. Infect. Dis.
158:
831-847, 1988). Ticarcillin dosages of either 96, 192, or 384 mg/day were administered at 1-, 2-, 3-, 4-, 8-, 12-, or 24-h intervals into a two-compartment model in order to duplicate the concentration-time profiles of the animal model. Colony counts were enumerated at 0 and 24 h. Linear regression and sigmoidal maximum-effect (Emax) model fitting were used to assess the relationship between the percentage of time that the concentration remained above the MIC (%
T
>MIC) or above four times the MIC (%
T
>4×MIC) and the change in the log
10
CFU per milliliter (Δlog
10
CFU/ml) in the central and peripheral compartments. Statistical analysis of the Δlog
10
CFU/ml values was performed for matched regimens of the in vitro and animal models based on the %
T
>MICs. The slopes of the regression equations of %
T
>MICs relative to Δlog
10
CFU/ml values were similar for the in vitro and animal models, but the
y
intercept was greater with the in vitro model. The Δlog
10
CFU/ml values of the 0- to 24-h colony counts at equivalent %
T
>MICs in the two models were not statistically different (
P
= 0.087). Overall, the peripheral compartment of the in vitro model was a better predictor of effect than the central compartment. This study, which compares pharmacodynamic principles between an in vitro and an animal model, demonstrated similar relationships between %
T
>MICs and effects.
In Vitro Activity of Caspofungin against
Candida albicans
Biofilms
Authors: Bachmann Stefano P. , VandeWalle Kacy , Ramage Gordon , Patterson Thomas F. , Wickes Brian L. , Graybill John R. , López-Ribot José L. 
Published: October 2002

ABSTRACT

Most manifestations of candidiasis are associated with biofilm formation on biological or inanimate surfaces.
Candida albicans
biofilms are recalcitrant to treatment with conventional antifungal therapies. Here we report on the activity of caspofungin, a new semisynthetic echinocandin, against
C. albicans
biofilms. Caspofungin displayed potent in vitro activity against sessile
C. albicans
cells within biofilms, with MICs at which 50% of the sessile cells were inhibited well within the drug's therapeutic range. Scanning electron microscopy and confocal scanning laser microscopy were used to visualize the effects of caspofungin on preformed
C. albicans
biofilms, and the results indicated that caspofungin affected the cellular morphology and the metabolic status of cells within the biofilms. The coating of biomaterials with caspofungin had an inhibitory effect on subsequent biofilm development by
C. albicans
. Together these findings indicate that caspofungin displays potent activity against
C. albicans
biofilms in vitro and merits further investigation for the treatment of biofilm-associated infections.
Organization of the Antiseptic Resistance Gene
qacA
and Tn
552
-Related β-Lactamase Genes in Multidrug- Resistant
Staphylococcus haemolyticus
Strains of Animal and Human Origins
Authors: Anthonisen I.-L. , Sunde M. , Steinum T. M. , Sidhu M. S. , Sørum H. 
Published: October 2002

ABSTRACT

A part (12 kb) of a plasmid containing the β-lactamase genes of Tn
552
, the disinfectant resistance gene
qacA
, and flanking DNA has been cloned from a
Staphylococcus haemolyticus
isolate and sequenced. This region was used to map the corresponding regions in six other multiresistant
S. haemolyticus
isolates of human and animal origin. The organizations of the genetic structures were almost identical in all isolates studied. The β-lactamase and
qacA
genes from
S. haemolyticus
have >99.9% identities at the nucleotide level with the same genes from
S. aureus
, demonstrating that various staphylococcal species able to colonize animal and human hosts can exchange the genetic elements involved in resistance to antibiotics and disinfectants. The use of antibiotics and disinfectants in veterinary practice and animal husbandry may also contribute to the selection and maintenance of resistance factors among the staphylococcal species. Different parts of the 12-kb section analyzed had high degrees of nucleotide identity with regions from several other different
Staphylococcus aureus
plasmids. This suggests the contribution of interplasmid recombination in the evolutionary makeup of this 12-kb section involving plasmids that can intermingle between various staphylococcal species. The lateral spread of resistance genes between various staphylococcal species is probably facilitated by the generation of large multiresistance plasmids and the subsequent interspecies exchange of them.
Antimicrobial Resistance in
Haemophilus influenzae
Isolated during Population-Based Surveillance for Meningitis in Salvador, Brazil
Authors: Reis Joice Neves , Lima Josilene Borges , Ribeiro Guilherme Souza , Corderio Soraia Machado , Salgado Kátia , Reis Mitermayer Galvão , Ko Albert I. 
Published: October 2002

ABSTRACT

Antimicrobial susceptibility was determined for 150
Haemophilus influenzae
isolates obtained during population-based surveillance for meningitis in Salvador, Brazil. Ten (6.7%) isolates were resistant to ampicillin and chloramphenicol. Of these, two isolates, a β-lactamase and non-β-lactamase producer, were resistant to amoxacillin-clavulinic acid. These findings indicate that present antibiotic regimens in Brazil may not be appropriate for the treatment of
H. influenzae
meningitis.
Comparative Evaluation of NCCLS M27-A and EUCAST Broth Microdilution Procedures for Antifungal Susceptibility Testing of Candida Species
Authors: Cuenca-Estrella Manuel , Lee-Yang Wendy , Ciblak Meral A. , Arthington-Skaggs Beth A. , Mellado Emilia , Warnock David W. , Rodriguez-Tudela Juan L. 
Published: October 2002

ABSTRACT

A two-laboratory study was performed to evaluate the correlation between the NCCLS M27-A and EUCAST microdilution procedures for antifungal testing of
Candida
spp. A panel of 109 bloodstream isolates was tested against amphotericin B, flucytosine, fluconazole, and itraconazole. Overall, the agreement was 92% and the intraclass correlation coefficient was 0.90 (
P
< 0.05).
Mutations in Ribosomal Protein L16 and in 23S rRNA in
Enterococcus
Strains for Which Evernimicin MICs Differ
Authors: Zarazaga Myriam , Tenorio Carmen , Del Campo Rosa , Ruiz-Larrea Fernanda , Torres Carmen 
Published: October 2002

ABSTRACT

Mutations in ribosomal protein L16 and in 23S rRNA were investigated in 22
Enterococcus
strains of different species and for which the MICs of evernimicin differ (MICs, 0.023 to 16 μg/ml). Amino acid changes (Arg56His, Ile52Thr, or Arg51His) in protein L16 were found in seven strains, and a nucleotide G2535A mutation in 23S rRNA was found in 1 strain among 13 for which the MICs are ≥1 μg/ml.
In Vitro Activities of Faropenem against 579 Strains of Anaerobic Bacteria
Authors: Wexler Hannah M. , Molitoris Denise , St. John Shahera , Vu Ann , Read Erik K. , Finegold Sydney M. 
Published: October 2002

ABSTRACT

The activity of faropenem, a new oral penem, was tested against 579 strains of anaerobic bacteria by using the NCCLS-approved reference method. Drugs tested included amoxicillin-clavulanate, cefoxitin, clindamycin, faropenem, imipenem, and metronidazole. Of the 176 strains of
Bacteroides fragilis
group isolates tested, two isolates had faropenem MICs of 64 μg/ml and imipenem MICs of >32 μg/ml. Faropenem had an MIC of 16 μg/ml for an additional isolate of
B. fragilis
; this strain was sensitive to imipenem (MIC of 1 μg/ml). Both faropenem and imipenem had MICs of ≤4 μg/ml for all isolates of
Bacteroides capillosus
(10 isolates),
Bacteroides splanchnicus
(13 isolates),
Bacteroides ureolyticus
(11 isolates),
Bilophila wadsworthia
(11 isolates),
Porphyromonas
species (42 isolates),
Prevotella
species (78 isolates),
Campylobacter
species (25 isolates),
Sutterella wadsworthensis
(11 isolates),
Fusobacterium nucleatum
(19 isolates),
Fusobacterium mortiferum/varium
(20 isolates), and other
Fusobacterium
species (9 isolates). Faropenem and imipenem had MICs of 16 to 32 μg/ml for two strains of
Clostridium difficile
; the MICs for all other strains of
Clostridium
tested (69 isolates) were ≤4 μg/ml. Faropenem had MICs of 8 and 16 μg/ml, respectively, for two strains of
Peptostreptococcus anaerobius
(MICs of imipenem were 2 μg/ml). MICs were ≤4 μg/ml for all other strains of gram-positive anaerobic cocci (53 isolates) and non-spore-forming gram-positive rods (28 isolates). Other results were as expected and reported in previous studies. No metronidazole resistance was seen in gram-negative anaerobes other than
S. wadsworthensis
(18% resistant); 63% of gram-positive non-spore-forming rods were resistant. Some degree of clindamycin resistance was seen in most of the groups tested.
Expression of SHV-2 β-Lactamase and of Reduced Amounts of OmpK36 Porin in
Klebsiella pneumoniae
Results in Increased Resistance to Cephalosporins and Carbapenems
Authors: Crowley Brendan , Benedí Vicente J. , Doménech-Sánchez Antonio 
Published: October 2002

ABSTRACT

A
Klebsiella pneumoniae
clinical isolate was resistant to cefoxitin, cefotaxime, ceftazidime, ceftazidime-clavulanate, piperacillin-tazobactam (MICs, >256 μg/ml in all cases), and meropenem (MIC, 16 μg/ml) and was intermediate to imipenem (MIC, 8 μg/ml). Decreased expression of the OmpK36 porin and expression of an SHV-2 β-lactamase contributed to the observed resistance to these β-lactam-containing agents.