bluuebunny/crossref_metadata_2025 huggingface dataset:
Locomotor deficits before and two months after knee arthroplasty
Authors: Ouellet Denise , Moffet Hélène
Published: October 2002

Objectives

To quantify the locomotor deficits before and 2 months after a total knee arthroplasty (TKA) in patients with osteoarthritis of the knee, and to compare pre‐ and postoperative performance.

Methods

Locomotor capacity of patients was evaluated using laboratory gait and stair‐ascent evaluations (kinematic and kinetic variables, electromyographic activity of 4 muscles of both lower limbs, and spatiotemporal parameters), the timed Up & Go (TUG), and the 6‐minute walk (6MW) test.

Results

Large locomotor deficits (increased hip flexion, decreased excursions of the knee and ankle, smaller extensor and flexor moments of force at the 3 joints, and muscle activation levels lower in all muscles tested) are still present in patients, particularly in the single‐limb support subphase before and 2 months after TKA. These deficits explain the slower walk and stair‐ascent speeds and a reduced performance at the TUG and 6MW tests.

Conclusions

These results emphasize the need for more careful followup and intensive rehabilitation programs in the first months following TKA.
J‐coupling and chemical‐shift evolution during I‐spin irradiation of ImSn systems: Product operator solutions and applications
Authors: Skinner Thomas E. , Bendall M. Robin
Published: October 2002

We previously obtained exact solutions for the time dependence of the density operator in weakly coupled spin‐½ ImSn systems during arbitrary RF irradiation of the I spins. The solutions for the density operator were written as explicit linear combinations of its product operator components (i.e., the operator basis set consisting of direct products of the I‐ and S‐spin operators). Other solutions for the product‐operator evolution of the density matrix have considered either evolution in the absence of RF irradiation or the case where the RF is sufficiently strong that J‐coupling effects can be ignored. The present solutions therefore extend the range of applications that are accessible to the product‐operator formalism and vector pictures of nuclear spin evolution. Here, we derive the solutions for an IS system in detail to illustrate the simplicity of the formalism and supplement our previous, but more general, abstract treatment of the subject. We then outline how the formalism is applied to the ImSn case. We also briefly discuss the rigorous vector picture that can be associated with the states of the system at each time. The solutions provide new insight into the combined effects of RF irradiation and J‐coupling. Applications include (1) novel methods for calibrating an RF channel for insensitive I spins by observing large signals from multiple quantum coherences with the S‐spin channel, and (2) new RF pulses for achieving selective coherence transfer. © 2002 Wiley Periodicals, Inc. Concepts Magn Reson 14: 287–307, 2002.
NMR nomenclature: Nuclear spin properties and conventions for chemical shifts (IUPAC recommendations 2001)
Authors: Harris Robin K. , Becker Edwin D. , Cabral De Menezes Sonia M. , Goodfellow Robin , Granger Pierre
Published: October 2002

A unified scale is recommended for reporting the NMR chemical shifts of all nuclei relative to the 1H resonance of tetramethylsilane. The unified scale is designed to provide a precise ratio, Ξ, of the resonance frequency of a given nuclide to that of the primary reference, the 1H resonance of tetramethylsilane (TMS) in dilute solution (volume fraction, φ < 1%) in chloroform. Referencing procedures are discussed, including matters of practical application of the unified scale. Special attention is paid to recommended reference samples and values of Ξ for secondary references on the unified scale are listed, many of which are the results of new measurements. Some earlier recommendations relating to the reporting of chemical shifts are endorsed. The chemical shift, δ, is redefined to avoid previous ambiguities but to leave practical usage unchanged. Relations between the unified scale and recently published recommendations for referencing in aqueous solutions (for specific use in biochemical work) are discussed, as well as the special effects of working in the solid state with magic‐angle spinning. In all, nine new recommendations relating to chemical shifts are made. Standardized nuclear spin data are also presented in tabular form for the stable (and some unstable) isotopes of all elements with non‐zero quantum numbers. The information given includes quantum numbers, isotopic abundances, magnetic moments, magnetogyric ratios and receptivities, together with quadrupole moments and linewidth factors (where appropriate). © 2001 IUPAC. Concepts Magn Reson 14:326–346, 2002
Management of membranoproliferative glomerulonephritis type II with plasmapheresis
Authors: Kurtz Kevin A. , Schlueter Annette J.
Published: October 2002

Membranoproliferative glomerulonephritis type II (MPGN II) is a rare kidney disease identified microscopically by electron‐dense deposits surrounded by complement component C3 in glomerular basement membranes. MPGN II usually leads to renal failure, and patients with MPGN II experience a high rate of recurrence following renal transplantation. No treatment modalities have been proven successful if recurrence does occur. The sera of most patients with MPGN II contain complement C3 nephritic factor (C3NF), an IgG autoantibody directed against C3 convertase (C3bBb) that results in constitutive breakdown of C3. C3NF may be important in the pathogenesis of the disease. Since C3NF is IgG, we predicted that C3NF could be removed from the serum through plasmapheresis. We describe the use of long‐term plasmapheresis to maintain good renal function in a 15‐year‐old girl with rapidly progressive recurrent MPGN II. After 73 plasmapheresis procedures over 63 weeks, her serum creatinine remained stable, and her creatinine clearance trended upward. Serial biopsies of the transplanted kidney demonstrated persistent MPGN II but no development of tubular atrophy. During the course of therapy, serum C3NF activity decreased; furthermore, C3NF activity was detected in the removed plasma. We have shown that plasmapheresis is a safe and effective method for delaying the onset of chronic renal failure in recurrent MPGN II. The efficacy may be due to the removal of serum C3NF. J. Clin. Apheresis 17:135–137, 2002. © 2002 Wiley‐Liss, Inc.
Synthesis of Brostallicin (PNU‐166196A) Labelled with 2H and 14C
Authors: Fontana E. , Pignatti A.
Published: October 2002

Brostallicin (PNU‐166196A), a DNA minor groove binder, has been labelled with 2H and 14C. The preparation of the deuterium specifically labelled [2H4]brostallicin was achieved according to a nine‐step sequence starting from 1,2‐diamino[1,1,2,2‐2H4]ethane (1). [14C]Brostallicin was obtained via a four‐step procedure in 31% overall radiochemical yield starting from 1‐methyl‐4‐nitropyrrole‐2‐[14C]carboxylic acid (9). Copyright © 2002 John Wiley & Sons, Ltd.
Synthesis of tritium labelled zaleplon
Authors: Shevchenko V.P. , Nagaev I.Yu. , Myasoedov N.F. , Susan A.
Published: October 2002

The reaction conditions for the incorporation of tritium into zaleplon have been investigated. The methods studied were the catalytic isotope exchange reaction with tritium gas and catalytic isotope exchange reaction with tritiated water. The results showed that the latter method was the method of choice giving a compound with a higher specific activity and a better yield. Copyright © 2002 John Wiley & Sons, Ltd.
Extracellular matrices associated with the apical surfaces of sensory epithelia in the inner ear: Molecular and structural diversity
Authors: Goodyear Richard J. , Richardson Guy P.
Published: October 2002

The ultrastructure and molecular composition of the extracellular matrices that are associated with the apical surfaces of the mechanosensory epithelia in the mouse inner ear are compared. A progressive increase in molecular and structural organization is observed, with the cupula being the simplest, the otoconial membrane exhibiting an intermediate degree of complexity, and the tectorial membrane being the most elaborate of the three matrices. These differences may reflect changes that occurred in the acellular membranes of the inner ear as a mammalian hearing organ arose during evolution from a simple equilibrium receptor. A comparison of the molecular composition of the acellular membranes in the chick inner ear suggests the auditory epithelium and the striolar region of the maculae are homologous, indicating the basilar papilla may have evolved from the striolar region of an otolithic organ. A comparison of the tectorial membranes in the chick cochlear duct and the mouse cochlea reveals differences in the structure of the noncollagenous matrix in the two species that may result from differences in the stochiometry of α‐ and β‐tectorin and/or differences in the post‐translational modification of α‐tectorin. This comparison also indicates that the appearance of collagen in the mammalian tectorial membrane may have been a major step in the evolution of an electromechanically tuned vertebrate hearing organ that operates over an extended frequency range. © 2002 Wiley Periodicals, Inc. J Neurobiol 53: 212–227, 2002
Chondroitin sulfate disrupts axon pathfinding in the optic tract and alters growth cone dynamics
Authors: Walz Andreas , Anderson Richard B. , Irie Atsushi , Chien Chi‐Bin , Holt Christine E.
Published: October 2002

Little is known about the cues that guide retinal axons across the diencephalon en route to their midbrain target, the optic tectum. Here we show that chondroitin sulfate proteoglycans are differentially expressed within the diencephalon at a time when retinal axons are growing within the optic tract. Using exposed brain preparations, we show that the addition of exogenous chondroitin sulfate results in retinal pathfinding errors. Retinal axons disperse widely from their normal trajectory within the optic tract and extend aberrantly into inappropriate regions of the forebrain. Time‐lapse analysis of retinal growth cone dynamics in vivo shows that addition of exogenous chondroitin sulfate causes intermittent stalling and increases growth cone complexity. These results suggest that chondroitin sulfate may modulate the guidance of retinal axons as they grow through the diencephalon towards the optic tectum. © 2002 Wiley Periodicals, Inc. J Neurobiol 53: 330–342, 2002
Evolution of structure and function of the hearing organ of lizards
Authors: Manley Geoffrey A.
Published: October 2002

Following their origin during the early Cretaceous, the lizards radiated early into a number of families. This radiation was accompanied by a diversification in the structure of the inner ear. The morphology of the auditory basilar papilla is family‐specific, with large variations in a number of parameters. At the physiologic level, this wide variation does not result in an equivalent range of physiologic parameters. This review considers the possible influence of various morphologic features on function, and correlates these features with physiologic response parameters. Anatomical variety that does not result in significant changes in the inputs to the brain is “neutral” with regard to selection pressures. This independence apparently removed evolutionary constraints and led to some of the great variety of auditory papillae seen. Other anatomical features are more important and do produce significant effects at the level of the auditory nerve. © 2002 Wiley Periodicals, Inc. J Neurobiol 53: 202–211, 2002
Hydroxyurea‐induced partial mushroom body ablation does not affect acquisition and retention of olfactory differential conditioning in honeybees
Authors: Malun Dagmar , Giurfa Martin , Galizia C. Giovanni , Plath Niels , Brandt Robert , Gerber Bertram , Eisermann Beate
Published: October 2002

The mushroom bodies (MBs), a paired structure in the insect brain, play a major role in storing and retrieving olfactory memories. We tested whether olfactory learning and odor processing is impaired in honeybees in which MB subunits were partially ablated. Using hydroxyurea (HU) to selectively kill proliferating cells, we created honeybees with varying degrees of MB lesions. Three‐dimensional reconstructions of brains were generated to analyze the drug‐induced morphological changes. These reconstructions show that, with few exceptions, only the MBs were affected by the drug, while other brain areas remained morphometrically intact. Typically, lesions affected only the MB in one hemisphere of the brain. To preclude HU‐induced physiologic deficits in the antennal lobe (AL) affecting olfactory learning, we measured the responses to odors in the AL using anin vivocalcium imaging approach. The response patterns did not differ between the AL of intact versus ablated brain sides within respective specimens. We, therefore, carried out side‐specific classical discriminative olfactory conditioning of the proboscis extension reflex (PER) with control bees and with HU‐treated bees with or without MB ablations. All experimental groups learned equally to discriminate and respond to a rewarded (CS+) but not to an unrewarded (CS−) conditioned stimulus during acquisition and retention tests. Thus, our results indicate that partial MB lesions do not affect this form of elemental olfactory learning. © 2002 Wiley Periodicals, Inc. J Neurobiol 53: 343–360, 2002
Transgenic and gene targeting studies of hair cell function in mouse inner ear
Authors: Zuo Jian
Published: October 2002

Despite 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

The 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

We 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

The 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

Self-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

The 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

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

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

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

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

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

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

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

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

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

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.
Using headspace gas monitoring to determine available carbon source (sodium acetate) in a biological nutrient removal process
Authors: Li J Z , Mavinic D S , Kelly H G
Published: October 2002

A utilizable carbonaceous substance is essential in the biological nutrient removal (BNR) of wastewater treatment, for denitrification and phosphorus removal. Accurate and prompt determination of these available carbon sources in each BNR stage is beneficial for operating control and process optimization. A new method and apparatus were developed using the carbon dioxide (CO2) detected in the headspace of a batch reactor, to estimate the carbon source available in the BNR process. Experimental results showed that detectable changes of CO2 concentration in the headspace reflected the sodium acetate utilization in the anaerobic and anoxic conditions, i.e., the P release and denitrification reactions. A series of clean water and activated sludge sample tests also verified that the headspace CO2 profiles were induced by the carbon utilization in BNR reactions. In the CO2 profiles of activated sludge sample with carbon source addition, the elapsed time (E Time) of CO2 evolution changes, during BNR reactions, was found proportional to the initial amount of carbon source added in solution. The E Time was also inversely proportional to the sludge concentration or the mixed liquor volatile suspended solids (MLVSS), at a constant carbon source addition. Results suggested that this E Time approach, using the headspace CO2 information, is capable of on-line determining the carbon source available in BNR reactions, as well as monitoring system performance. Key words: biological nutrient removal (BNR), carbon dioxide, headspace monitoring, volatile fatty acids (VFAs).
Characterizing sediment sources and natural hydrocarbon inputs in the lower Athabasca River, Canada
Authors: Conly F M , Crosley R W , Headley J V
Published: October 2002

The Athabasca River drains an area of 160 000 km2 in northern Alberta, Canada, with much of the lower basin underlain by oil-sand deposits. The oil sands occur primarily in the McMurray Formation of the Cretaceous Period, with outcrops evident along the banks of the Athabasca River, as well as the lower portions of several tributaries. Since the oil sands represent a natural diffuse source of hydrocarbons to the aquatic environment, understanding the nature and extent of sediment-bound hydrocarbon contaminants in the context of the sediment regime of the Athabasca River is important. Described are fluvial geomorphic characteristics of the lower Athabasca River, which provide a basis for assessing sediment-bound hydrocarbon contaminants. Suspended sediment derived from main stem and tributary sources between Fort McMurray and Embarras account for 1.2 Mt, or 18%, of the mean annual load of the Athabasca River. Of this load, approximately 53% of the sediment input originated from tributaries, the remainder from main-stem sources. The majority of sediment contributed along the main stem occurs in the vicinity of Embarras, well downstream of oil-sand sources. Natural oil-sand sediment contributions are likely much less than 3% of the annual load downstream of Fort McMurray. Key words: sediment, fluvial geomorphology, oil sands, hydrocarbons, polycyclic aromatic hydrocarbon (PAH), contaminants, environmental monitoring, Athabasca River.
L'enneigement hivernal : un facteur de variation du recrutement chez l'isard (Rupicapra pyrenaica pyrenaica)
Authors: Crampe J -P , Gaillard J -M , Loison A
Published: October 2002

To assess the relationships between winter climatic conditions and population dynamics of mountain ungulates, we monitored over the long term an unhunted isard (Rupicapra pyrenaica pyrenaica) population living in the Pyrénées National Park. We used general linear modelling to assess (i) the influence of the observation date (between November and April) of the transect sampled and of the year on population recruitment (proportion of females 2 years of age and older with kids at heel) and (ii) the impact of snow accumulation during winter (cumulated snow fall from November to April) on kid mortality. As expected, the mean number of kids per female decreased over the observation period. The mean number of kids per female showed marked among-year differences in initial recruitment (measured on 31 October) as well as in kid mortality (measured as the decrease in recruitment between 31 October and 31 March). This model accounted for 80% of the variability observed in the field data. Among-year differences in snow accumulation accounted for most (86%) of the yearly variation observed in kid mortality. Our study demonstrates that winter snow may severely affect juvenile survival, and thereby population dynamics of mountain ungulates.
The effects of increased flow rates on linear dominance hierarchies and physiological function in brown trout, Salmo trutta
Authors: Sloman Katherine A , Wilson Linda , Freel June A , Taylor Alan C , Metcalfe Neil B , Gilmour Kathleen M
Published: October 2002

The formation of dominance hierarchies within groups of salmonid fish is well documented and stream tanks are often used to create environmentally relevant conditions in which to study this aspect of fish behaviour. Although stream tanks simulate the natural environment of the fish in many ways, they have limitations in that they provide the fish with a rather predictable and constant habitat. The present study illustrates that under these constant conditions, the behaviour of fish in their natural environment may not be truly represented. Under constant conditions hierarchies were formed among groups of four brown trout, Salmo trutta, and the dominant fish displayed physiological advantages. However, when an environmental perturbation of increased water flow, simulating a spate, was imposed, the social behaviour of the fish was altered and the physiological advantages of dominance were lost. Clearly, environmental changes affect the behaviour, and consequently the physiology, of salmonid fish, therefore the importance of taking environmental disturbances into consideration in studies of salmonid behaviour should not be underestimated.
Measures of breeding inequality: a case study in southern elephant seals
Authors: Galimberti Filippo , Fabiani Anna , Sanvito Simona
Published: October 2002

Inequality in distribution of resources is a key aspect of evolutionary biology particularly in relation to distribution of mates and copulations. Notwithstanding its important role, inequality is not easily defined, and its measurement is complicated by theoretical and methodological issues. Although the formal treatment of inequality has been mostly limited to the evolution of lek mating system, a methodologically correct approach to measurement of inequality is generally valid for the study of any kind of mating system. In this paper, we analyze inequality in a large set of southern elephant seal (Mirounga leonina) harems. The observed distribution of fertilizations was significantly different from both the expected distribution with equal shares of resources and the expected distribution with equal propensities to acquire resources. We calculate and compare various measures of inequality, observing a wide variation particularly among unbounded and bounded indices. We check the effect of choosing a specific measure of inequality by considering the effect of two aspects of harem socionomy, the number of females in the harem (i.e., the total amount of resources to be shared) and the number of males associated with the harem (i.e., the number of competitors). The choice of a specific measure of inequality had a strong impact on the results obtained and should be considered a critical step in every study of functional and evolutionary correlates of inequality. Unbounded indices showed a strong relationship with both harem size and number of males, while no effect was evident in the analysis of bounded indices. This demonstrates that, in this species, the despotism of the mating system remains high even in large harems and with many competitors, i.e., the worst conditions for monopolization.
A VARIATIONAL CALCULATION OF LIGHT HYPERNUCLEI
Authors: PANDA P. K. , SAHU R.
Published: October 2002

A nonperturbative variational calculation has been made for the s-shell hypernuclei. Here we dress the Λ- and Σ0- hypernuclei with off-mass shell pion pairs. The analysis replaces the scalar isoscalar potential by quantum coherent states. The binding energies of 4+nΛ He (n=0,1,2) agree quite well with the RMF result. The experimental binding energies of 4 He and 3 He are reasonably well reproduced in our calculation. A satisfactory description of the relevant experimental Λ- and Σ- separation energies has been obtained.
RHO PRODUCTION IN PROTON-NUCLEUS COLLISION
Authors: DAS SWAPAN , JAIN B. K. , SANTRA A. B.
Published: October 2002

With the final aim to explore the effect of the medium on hadron masses we study the reaction mechanism for the (p,p′ρ0) reaction on nuclei. We focus on the amplitudes which are dominated by the N*(1720)P13 resonance in intermediate state. This resonance has about 80% decay probability to Nρ channel. A nonrelativistic formalism is written for different amplitudes. The theoretical cross sections are presented for the 12 C target nucleus around 3 GeV beam energy. These results are found to be sensitive to the N* as well as ρ mass modifications in the medium. These two effects in the p′ spectrum can be separated experimentally as they are found to occur at different values of the p′ momentum. Because of the exploratory nature of this investigation, simple forms are used for the bound-state wave functions, and the continuum particles are approximated by plane waves.
Transduction of donor hematopoietic stem-progenitor cells with Fas ligand enhanced short-term engraftment in a murine model of allogeneic bone marrow transplantation
Authors: Whartenby Katharine A. , Straley Erin E. , Kim Heeje , Racke Frederick , Tanavde Vivek , Gorski Kevin S. , Cheng Linzhao , Pardoll Drew M. , Civin Curt I.
Published: October 2002

Fas-mediated apoptosis is a major physiologic mechanism by which activated T cells are eliminated after antigen-stimulated clonal expansion generates a specific cellular immune response. Because activated T cells are the major effectors of allograft rejection, we hypothesized that genetically modifying allogeneic bone marrow (BM) cells prior to transplantation could provide some protection from host T-cell attack, thus enhancing donor cell engraftment in bone marrow transplantation (BMT). We undertook studies to determine the outcome of lentiviral vector-mediated transduction of Fas ligand (FasL) into lineage antigen-negative (lin−) mouse BM cells (lin− BMs), in an allogeneic BMT model. FasL-modified lin− BMs killed Fas-expressing T cells in vitro. Mice that received transplants of allogeneic FasL+ lin−BMs had enhanced short-term engraftment, after nonmyeloablative conditioning, as compared to controls. We observed no major hepatic toxicity or hematopoietic or immune impairment in recipient mice at these time points. These results suggest potential therapeutic approaches by manipulating lymphohematopoietic stem-progenitor cells to express FasL or other immune-modulating genes in the context of BMT.