bluuebunny/crossref_metadata_2025 huggingface dataset:
Molecular Forensic Profiling of
Cryptosporidium
Species and Genotypes in Raw Water
Authors: Ruecker Norma J. , Bounsombath Niravanh , Wallis Peter , Ong Corinne S. L. , Isaac-Renton Judith L. , Neumann Norman F.
Published: December 2005

The emerging concept of host specificity of
Cryptosporidium
spp. was exploited to characterize sources of fecal contamination in a watershed. A method of molecular forensic profiling of
Cryptosporidium
oocysts on microscope slides prepared from raw water samples processed by U.S. Environmental Protection Agency Method 1623 was developed. The method was based on a repetitive nested PCR-restriction fragment length polymorphism-DNA sequencing approach that permitted the resolution of multiple species/genotypes of
Cryptosporidium
in a single water sample.
Distribution of Serotypes and Antimicrobial Resistance Genes among
Streptococcus agalactiae
Isolates from Bovine and Human Hosts
Authors: Dogan Belgin , Schukken Y. H. , Santisteban C. , Boor Kathryn J.
Published: December 2005

To better understand the emergence and transmission of antibiotic-resistant
Streptococcus agalactiae
, we compared phenotypic and genotypic characteristics of 52 human and 83 bovine S.
agalactiae
isolates. Serotypes found among isolates from human hosts included V (48.1%), III (19.2%), Ia and Ib (13.5% each), and II (5.8%). Among isolates from bovine hosts, molecular serotypes III and II were predominant (53 and 14.5%, respectively). Four and 21 different ribotypes were found among human and bovine isolates, respectively. A combination of ribotyping and serotyping showed that two bovine isolates were indistinguishable from human isolates. Resistance to tetracycline and erythromycin was more common among human (84.6% and 26.9%, respectively) than bovine (14.5% and 3.6%, respectively) isolates.
tetM
was found in all tetracycline-resistant human isolates, while
tetO
was the predominant resistance gene among bovine isolates.
tet
genes were found among various ribotypes.
ermB
,
ermTR
, and
mefA
were detected among erythromycin-resistant human isolates, while
ermB
was the only erythromycin resistance determinant among isolates from bovine hosts. For isolates from human hosts, erythromycin resistance genes appeared to be associated with specific ribotypes. We conclude that (i) human and bovine S.
agalactiae
isolates represent distinct populations; (ii) human host-associated
S. agalactiae
subtypes may occasionally be transmitted to bovines; (iii) while emergence of erythromycin and tetracycline resistance appears to largely occur independently among human and bovine isolates, occasional cross-species transfer of resistant strains or transmission of resistance genes between human- and bovine-associated subtypes may occur; and (iv) dissemination of antibiotic-resistant
S. agalactiae
appears to include both clonal spread of resistant strains as well as horizontal gene transfer.
High Prevalence of Human Papillomavirus Infections in Urine Samples from Human Immunodeficiency Virus-Infected Men
Authors: Smits Paul H. M. , Bakker Remco , Jong Eefje , Mulder Jan Willem , Meenhorst Pieter L. , Kleter Bernhard , van Doorn Leen-Jan , Quint Wim G. V.
Published: December 2005

Infection with human immunodeficiency virus (HIV) and the resulting immunosuppression are associated with an increased risk for human papillomavirus (HPV) persistence and related malignancies. In the present study we investigated the prevalence of HPV in urine samples from 104 HIV-infected men with low CD4+cell counts (<100 per mm3) and 115 urine samples from HIV-negative men. A high prevalence of HPV DNA (39.4%) was found in the HIV patients. Most of the HPV types were high risk (81.4%), with HPV 52 as the most prevalent type (12.5%), followed by HPV 18 (6.7%), HPV 35 (5.8%), and HPV 70 (4.8%). Multiple HPV genotypes were observed in 17 (41%) of the 41 HPV- and HIV-positive men. In contrast, only 11 (9.6%) HPV DNA-positive cases were observed among the 115 HIV-uninfected men, and 3 (27.3%) contained multiple genotypes. Quantitative analyses indicated that the HPV viral load, as measured in urine samples, is significantly higher in HIV-positive men compared to HIV-negative men. In the present study we show that urine samples are useful for detecting HPV DNA, there is a high prevalence of HPV in HIV-positive men, and the HPV viral load is substantially higher in HIV-positive than in HIV-negative men. More studies are needed to evaluate the risk and natural development of HPV-related malignancies in HIV-positive men.
Comparison of Two Target Genes for Detection and Genotyping of
Giardia lamblia
in Human Feces by PCR and PCR-Restriction Fragment Length Polymorphism
Authors: Bertrand Isabelle , Albertini Laetitia , Schwartzbrod Janine
Published: December 2005

A PCR assay targeting the
tpi
gene was developed to detect and to genotype
Giardia lamblia
in human feces. Our assay was specific and discriminated between
G. lamblia
assemblages A and B.
G. lamblia
cysts isolated from human feces were also analyzed with two previously described PCR-restriction fragment length polymorphism (RFLP) assays, which are based on the detection of
tpi
or
gdh
genes. These RFLP analyses distinguished groups I and II within assemblage A or groups III and IV within assemblage B. Among 26 fecal samples from patients with sporadic giardiasis diagnosed by hospital laboratories, the
tpi
gene was amplified from 25 (96%) with our PCR assay, whereas only 21 (81%) samples were positive when the
gdh
gene was targeted. Of the 25 positive samples, nine (36%) contained assemblage A and 16 (64%) contained assemblage B. Thus, RFLP analysis classified eight samples (32%) in assemblage A group II, eight (32%) in assemblage B group III, and five (20%) in assemblage B group IV. The group could not be specified for four samples. The
tpi
and
gdh
genes of
G. lamblia
assemblage B were amplified from 14 (93%) of 15 samples collected only from French soldiers coming back from the Ivory Coast. All of these contained assemblage B group III. The PCR method developed is sensitive, simple, and specific and shows that the
tpi
gene is well adapted for
G. lamblia
genotyping.
Evaluation of a (1→3)-β-
d
-Glucan Assay for Diagnosis of Invasive Fungal Infections
Authors: Pickering Jerry W. , Sant Howard W. , Bowles Catherine A. P. , Roberts William L. , Woods Gail L.
Published: December 2005

The Fungitell assay (Associates of Cape Cod, Inc.) is a commercial test that detects (1-3)-β-
d
-glucan (BG) and is intended for diagnosis of invasive fungal infections. To evaluate the Fungitell assay, we tested serum and plasma samples from healthy blood donors and from patients with blood cultures positive for yeast or bacteria. All
36 blood donors were BG negative, and 13 of 15 candidemic patients were
BG positive. Of 25 bacteremic patients, 14 (10 with gram-positive
bacteremia) were BG positive. One of the latter patients with
Staphylococcus aureus
bacteremia also had invasive
candidiasis, based on histological findings in a tissue biopsy;
therefore, the BG result was a true positive. The sensitivity,
specificity, and positive and negative predictive values of the
Fungitell assay, by patient, for these three groups were 93.3%, 77.2%,
51.9%, and 97.8%, respectively. We also performed the Fungitell assay
on sera that had been tested for
Aspergillus
galactomannan or
Histoplasma
antigen. All six
Histoplasma
antigen-positive patients and 31 of 32
Aspergillus
galactomannan-positive patients were also BG positive. BG results for
the 10
Histoplasma
antigen-negative and the 32
Aspergillus
galactomannan-negative patients varied, but we
were unable to confirm many of the results. Between-run coefficients of
variance (CVs) for the assay ranged from 3.2% to 16.8%; within-run CVs
were ≤4.8%. The correlation coefficient for an interlaboratory
reproducibility study was 0.9892. Concentrations of hemoglobulin,
bilirubin, and triglycerides that caused 20% interference were 588, 72,
and 466 mg/dl, respectively. Our results suggest that the Fungitel
assay may be most useful for excluding invasive fungal
infection.
Rapid Determination of Rifampin Resistance in Clinical Isolates of
Mycobacterium tuberculosis
by Real-Time PCR
Authors: Kocagoz Tanil , Saribas Zeynep , Alp Alpaslan
Published: December 2005

Real-time PCR was used to determine rifampin resistance in clinical isolates of
Mycobacterium tuberculosis
. Ninety-six rifampin-resistant isolates and 23 rifampin-susceptible isolates were included in the study. A 305-bp region covering the 81-bp “rifampin resistance-determining region” of
rpoB
was amplified. Two hybridization probe pairs that covered the most frequent mutation sites in
rpoB
, codon regions 526 to 531 and 513 to 516, were used. The results obtained by real-time PCR were compared to those obtained by the proportion method. For detection of rifampin resistance, the real-time PCR assay yielded a sensitivity of 92.7% and a specificity of 100%. Real-time PCR is a very rapid method, and it can be especially helpful for the reporting of resistant clinical isolates in a very short period of time.
Use of Phylogenetic and Phenotypic Analyses To Identify Nonhemolytic Streptococci Isolated from Bacteremic Patients
Authors: Hoshino Tomonori , Fujiwara Taku , Kilian Mogens
Published: December 2005

The aim of this study was to evaluate molecular and phenotypic methods for the identification of nonhemolytic streptococci. A collection of 148 strains consisting of 115 clinical isolates from cases of infective endocarditis, septicemia, and meningitis and 33 reference strains, including type strains of all relevantStreptococcusspecies, were examined. Identification was performed by phylogenetic analysis of nucleotide sequences of four housekeeping genes,ddl,gdh,rpoB, andsodA; by PCR analysis of the glucosyltransferase (gtf) gene; and by conventional phenotypic characterization and identification using two commercial kits, Rapid ID 32 STREP and STREPTOGRAM and the associated databases. A phylogenetic tree based on concatenated sequences of the four housekeeping genes allowed unequivocal differentiation of recognized species and was used as the reference. Analysis of single gene sequences revealed deviation clustering in eight strains (5.4%) due to homologous recombination with other species. This was particularly evident inS. sanguinisand in members of the anginosus group of streptococci. The rate of correct identification of the strains by both commercial identification kits was below 50% but varied significantly between species. The most significant problems were observed withS. mitisandS. oralisand 11Streptococcusspecies described since 1991. Our data indicate that identification based on multilocus sequence analysis is optimal. As a more practical alternative we recommend identification based onsodAsequences with reference to a comprehensive set of sequences that is available for downloading from our server. An analysis of the species distribution of 107 nonhemolytic streptococci from bacteremic patients showed a predominance ofS. oralisandS. anginosuswith various underlying infections.
Use of a Commercially Available Line Probe Assay for Genotyping of Hepatitis C Virus 5a Strains
Authors: Verbeeck Jannick , Maes Piet , Wollants Elke , Van der Merwe Schalk , Song Ernie , Nevens Frederik , Van Ranst Marc
Published: December 2005

To validate a commercially available line probe assay for samples containing the infrequently found hepatitis C virus (HCV) genotype 5a, we sequenced a 511-nucleotide fragment of the NS4b region of Belgian and South African HCV genotype 5a samples. Phylogenetic analysis of the sequence data was performed. For the 77 HCV genotype 5a samples collected, there was 100% concordance between the genotype assignment by the line probe assay and the genotyping based on nucleotide sequencing, despite sequence heterogeneity in the probe binding sites of some samples.
Broth Microdilution Susceptibility Testing of
Campylobacter jejuni
and the Determination of Quality Control Ranges for Fourteen Antimicrobial Agents
Authors: McDermott Patrick F. , Bodeis-Jones Sonya M. , Fritsche Thomas R. , Jones Ronald N. , Walker Robert D. , Campylobacter Susceptibility Testing Group the
Published: December 2005

Quality control ranges were developed for broth microdilution testing of
Campylobacter jejuni
ATCC 33560 against 14 antimicrobials. Cation-adjusted Mueller-Hinton broth containing 2.5% laked horse blood was the preferred medium, with incubation in a microaerobic atmosphere of 10% CO
2
, 5% O
2
, and 85% N
2
at 36°C for 48 h or 42°C for 24 h.
Nocardia ignorata
, a New Agent of Human Nocardiosis Isolated from Respiratory Specimens in Europe and Soil Samples from Kuwait
Authors: Rodríguez-Nava Verónica , Couble Andrée , Khan Z. U. , Pérouse de Montclos M. , Brasme L. , Villuendas Cruz , Molinard Claudie , Boiron Patrick , Laurent Frédéric
Published: December 2005

Nocardia ignorata
is a recently described species identified on the basis of a single isolate of unknown origin. Here we describe the epidemiological, phenotypic, and phylogenetic characteristics of this new species, based on five new clinical and soil isolates.
Thyroid Abscess Due to a Mixed Anaerobic Infection with
Fusobacterium mortiferum
Authors: Stavreas Nikolaos P. , Amanatidou Constantina D. , Hatzimanolis Emmanuel G. , Legakis Ioannis , Naoum George , Lakka-Papadodima Elli , Georgoulias George , Morfou Panagiota , Tsiodras Sotirios
Published: December 2005

A rare case of a thyroid abscess due to mixed anaerobic flora containing
Fusobacterium mortiferum
in an immunocompetent patient is described. The patient was successfully treated with immediate surgical intervention and appropriate antimicrobial agents.
Transmission of a Panton-Valentine Leucocidin-Positive, Methicillin-Resistant
Staphylococcus aureus
Strain between Humans and a Dog
Authors: van Duijkeren E. , Wolfhagen M. J. H. M. , Heck M. E. O. C. , Wannet W. J. B.
Published: December 2005

Panton-Valentine leucocidin-positive methicillin-resistant
Staphylococcus aureus
(MRSA) strains with identical resistance patterns were cultured from recurrent infections of a 51-year-old patient, her healthy husband, son, and dog, and pulsed-field gel electrophoresis showed that all MRSA strains were indistinguishable.
Study of the effect of alkalis on the slag cement systems
Authors: Zeghichi L , Mezghiche B , Chebili R
Published: December 2005

The replacement of natural materials by industrial by-products has given a variety of new construction materials that are economically viable and ecologically beneficial. Blast furnace slag is one of these industrial by-products. Its beneficial proprieties and characteristics have led to rapid growth of production in Algeria and worldwide. This research deals with the effect of alkaline activation of slag cement with clinker. Various agents that activate the process were used for testing, and it showed that compressive strength at 28 d, which reached 150% with respect to compressive strength obtained from slag cement at different percentages of slag (50%–80%), increased considerably. Alkaline activators accelerate hydration and stimulate the hardening process. The results also show the efficacy of steam cured treatment on the compressive strength.Key words: slag cement, activation agent, hydration, hardening, steam curing.
Asynchronous seismic analysis of concrete-faced rockfill dams including dam–reservoir interaction
Authors: Bayraktar Alemdar , Haciefendioglu Kemal , Muvafik Murat
Published: December 2005

Seismic response of concrete-faced rockfill (CFR) dams subjected to asynchronous base excitation is determined by considering dam–reservoir interaction. The equations of motion of the coupled system are obtained using the Lagrangian approach, and the surface sloshing motion is included in the finite element formulation. Torul dam constructed in the city, Gumushane, Turkey, is selected as a numerical example, and its material properties are considered in the analysis. The dam–reservoir interaction system is modelled using the Lagrangian (displacement-based) fluid and solid-quadrilateral-isoparametric finite elements. The east–west component of Erzincan earthquake, which occurred on 13 March 1992, recorded near the region of the dam is used as a ground motion. Propagation velocities of the seismic wave are chosen as 1000 m/s, 3000 m/s, and infinite. Stresses are calculated for empty and full reservoir cases and compared with each other.Key words: concrete-faced rockfill dam, Lagrangian approach, dam–reservoir interaction, finite element method, earthquake.
Hsp90: a chaperone for protein folding and gene regulation
Authors: Zhao Rongmin , Houry Walid A
Published: December 2005

Molecular chaperones are essential components of a quality control machinery present in the cell. They can either aid in the folding and maintenance of newly translated proteins, or they can lead to the degradation of misfolded and destabilized proteins. Hsp90 is a key member of this machinery. It is a ubiquitous molecular chaperone that is found in eubacteria and all branches of eukarya. It plays a central role in cellular signaling since it is essential for maintaining the activity of several signaling proteins, including steroid hormone receptors and protein kinases. Hsp90 is currently a novel anticancer drug target since it is overexpressed in some cancer cells. The chaperone typically functions as part of large complexes, which include other chaperones and essential cofactors that regulate its function. It is thought that different cofactors target Hsp90 to different sets of substrates. However, the mechanism of Hsp90 function remains poorly understood. As part of an effort to elucidate the Hsp90 chaperone network, we carried out a large-scale proteomics study to identify physical and genetic interactors of the chaperone. We identified 2 highly conserved novel Hsp90 cofactors, termed Tah1 and Pih1, that bind to the chaperone and that also associate physically and functionally with the essential DNA helicases Rvb1 and Rvb2. These helicases are key components of the chromatin remodeling complexes Ino80 and SWR-C. Tah1 and Pih1 seem to represent a novel class of Hsp90 cofactors that allow the chaperone to indirectly affect gene regulation in the cell in addition to its ability to directly promote protein folding. In this review, we provide an overview of Hsp90 structure and function, and we discuss the literature that links the chaperone activity to gene regulation.Key words: Hsp90, chaperone, cochaperone, gene regulation, protein folding.
Conserved P-loop GTPases of unknown function in bacteria: an emerging and vital ensemble in bacterial physiology
Authors: Brown Eric D
Published: December 2005

Establishing the roles of conserved gene products in bacteria is of fundamental importance to our understanding of the core protein complement necessary to sustain cellular life. P-loop GTPases and related ATPases represent an abundant and remarkable group of proteins in bacteria that, in many cases, have evaded characterization. Here, efforts aimed at understanding the cellular function of a group of 8 conserved, poorly characterized genes encoding P-loop GTPases, era, obg, trmE, yjeQ, engA, yihA, hflX, ychF, and a related ATPase, yjeE, are reviewed in considerable detail. While concrete cellular roles remain elusive for all of these genes and considerable pleiotropy has plagued their study, experiments to date have frequently implicated the ribosome. In the case of era, obg, yjeQ, and engA, the evidence is most consistent with roles in ribosome biogenesis, though the prediction is necessarily putative. While the protein encoded in trmE clearly has a catalytic function in tRNA modification, the participation of its GTPase domain remains obscure, as do the functions of the remaining proteins. A full understanding of the cellular functions of all of these important proteins remains the goal of ongoing studies of cellular phenotype and protein biochemistry.Key words: GTPase, unknown function, essential gene, P-loop.
Review of procaryote metabolism in view of modeling microbial adaptation from fast growth to starvation conditions
Authors: Lavallée B , Lessard P , Vanrolleghem P A
Published: December 2005

More than 50 years ago, Monod (1949) proposed the application of the Michaelis–Menten relation describing enzyme kinetics to a culture of microorganisms. For the purpose of simplification, the mathematical relation proposed by Monod (1949) reduced the entire cell to a single enzyme genetically expressed in a single intensity. However, cell metabolism is based on a large number of biochemical reactions. This paper reviews the literature to identify the controlling factors of cell metabolism and the regulation of specific activity of the cell. The literature review was designed to highlight which regulation mechanisms induce a growth-rate variation so that they can be expressed mathematically. The study of these processes will focus on modeling the specific activity variation. The review is limited to heterotrophic procaryote organisms under aerobic conditions. Key words: modeling, metabolism, regulation, growth rate, cell death, maintenance, activated sludge.
Effects of rainfall events on waste-rock surface-water conditions and CO2 effluxes across the surfaces of two waste-rock piles
Authors: Kabwe L K , Wilson G W , Hendry M J
Published: December 2005

The influence of rainfall events on the surface-water conditions of waste rock and the resultant CO2 gas effluxes from waste-rock piles are of value in the development of a long-term management plan for these piles. However, data for the direct measurement of CO2 effluxes through field-scale waste-rock piles are lacking. This study investigated the influence of a short-term, multi-day (29 July to 5 August 2002) heavy rainfall event on waste-rock water conditions and CO2 effluxing from two large waste-rock piles at the Key Lake uranium mine in northern Saskatchewan. The study also investigated spatial and temporal variation in CO2 effluxes in these waste-rock piles over a 2-year period (summer 2000 – summer 2002). Results showed that the impact of a heavy rainfall event on surface-water conditions and CO2 effluxes from these waste-rock piles is of relatively short duration. Results also showed that the CO2 effluxes were relatively uniform, both spatially and temporally (average covariance (CV) is 28%–39%), over the 2-year test period. This information can provide an important tool in the development of a long-term management plan for mine waste-rock piles. Key words: CO2 efflux, waste-rock piles, rainfall events, unsaturated zone.
Numbers of fecal streptococci and Escherichia coli in fresh and dry cattle, horse, and sheep manure
Authors: Weaver R W , Entry J A , Graves Alexandria
Published: December 2005

Livestock are known contributors to stream pollution. Numbers of fecal streptococci and Escherichia coli in manure naturally deposited by livestock in the field are needed for activities related to bacterial source tracking and determining maximum daily bacterial loading of streams. We measured populations of fecal streptococci and E. coli in fresh and dry manure from cattle (Bos taurus L.), horses (Equus caballus L.), and sheep (Ovis aires L.) on farms in southern Idaho. Populations of indicator bacteria in dry manure were often as high as that in fresh manure from horse and sheep. There was a 2 log10 drop in the population of fecal coliform numbers in dry cattle manure from cattle in pastures but not from cattle in pens. Bacterial isolates used in source tracking should include isolates from both fresh and dry manure to better represent the bacterial source loading of streams.Key words: enterococci, E. coli, fecal streptococci, bacterial indicators, bacterial source tracking, pollution.
Evidence for mitochondrial gene control of mating types inPhytophthora
Authors: Gu Yu-Huan , Ko Wen-Hsiung
Published: December 2005

When protoplasts carrying metalaxyl-resistant (Mr) nuclei from the A1 isolate of Phytophthora parasitica were fused with protoplasts carrying chloroneb-resistant (Cnr) nuclei from the A2 isolate of the same species, fusion products carrying Mrnuclei were either the A2 or A1A2 type, while those carrying Cnrnuclei were the A1, A2, or A1A2 type. Fusion products carrying Mrand Cnrnuclei also behaved as the A1, A2, or A1A2 type. The result refutes the hypothesis that mating types in Phytophthora are controlled by nuclear genes. When nuclei from the A1 isolate of P. parasitica were fused with protoplasts from the A2 isolate of the same species and vice versa, all of the nuclear hybrids expressed the mating type characteristics of the protoplast parent. The same was true when the nuclei from the A1 isolate of P. parasitica were fused with the protoplasts from the A0 isolate of Phytophthora capsici and vice versa. These results confirm the observation that mating type genes are not located in the nuclei and suggest the presence of mating type genes in the cytoplasms of the recipient protoplasts. When mitochondria from the A1 isolate of P. parasitica were fused with protoplasts from the A2 isolate of the same species, the mating type of three out of five regenerated protoplasts was changed to the A1 type. The result demonstrated the decisive effect of mitochondrial donor sexuality on mating type characteristics of mitochondrial hybrids and suggested the presence of mating type genes in mitochondria. All of the mitochondrial hybrids resulting from the transfer of mitochondria from the A0 isolate of P. capsici into protoplasts from the A1 isolate of P. parasitica were all of the A0 type. The result supports the hypothesis of the presence of mating type genes in mitochondria in Phytophthora.Key words: mating type, mitochondrial gene, Phytophthora parasitica, Phytophthora capsici.
Development of a rapid identification method forAeromonasspecies by multiplex-PCR
Authors: Sen Keya
Published: December 2005

Existing biochemical methods cannot distinguish among some species of Aeromonads, while genetic methods are labor intensive. In this study, primers were developed to three genes of Aeromonas: lipase, elastase, and DNA gyraseB. In addition, six previously described primer sets, five corresponding to species-specific signature regions of the 16S rRNA gene from A. veronii, A. popoffii, A. caviae, A. jandaei, and A. schubertii, respectively, and one corresponding to A. hydrophila specific lipase (hydrolipase), were chosen. The primer sets were combined in a series of multiplex-PCR (mPCR) assays against 38 previously characterized strains. Following PCR, each species was distinguished by the production of a unique combination of amplicons. When the assays were tested using 63 drinking water isolates, there was complete agreement in the species identification (ID) for 59 isolates, with ID established by biochemical assays. Sequencing the gyrB and the 16S rRNA gene from the remaining four strains established that the ID obtained by mPCR was correct for three strains. For only one strain, no consensus ID could be obtained. A rapid and reliable method for identification of different Aeromonas species is proposed that does not require restriction enzyme digestions, thus simplifying and speeding up the process.Key words: Aeromonas, multiplex-PCR, identification.
Determination of susceptibility/resistance to antifungal drugs ofTrichophyton mentagrophytesisolates by a macrodilution method
Authors: da Silva Barros Maria Elisabete , Hamdan Júnia Soares
Published: December 2005

Onychomycosis is a common adult human mycosis, and dermatophytes of the Trichophyton genera are the most frequently isolated microorganism. Globally, from 3% to 10% of the human population is attacked by ony cho mycosis, and many cases involve toenails. The aim of this work was to determine the minimal inhibitory concentrations (MICs) of antifungal drugs (fluconazole, ketoconazole, itraconazole, terbinafine, and griseofulvin) often used for the treatment of ungueal dermatophytosis caused by Trichophyton mentagrophytes. The MICs were determined by the broth medium macrodilution method. The results showed that activities of terbinafine and itraconazole were significantly higher (MIC <0.007–0.015 µg·mL–1and MIC = 0.062–1.000 µg·mL–1, respectively). All isolates had reduced susceptibility to fluconazole (MIC = 16 to >64 µg·mL–1). The MICs of ketoconazole and griseofulvin varied among strains, ranging from 0.125 to 2.000 µg·mL–1for ketoconazole and from 0.25 to 2.00 µg·mL–1for griseofulvin. These MICs were higher than those of other studies cited, possibly because of differences in culture medium used in the other studies.Key words: dermatophytes, susceptibility testing, macrodilution, onychomycosis, antifungal drugs.
Mechanisms of mechanical strain memory in airway smooth muscle
Authors: Kim Hak Rim , Hai Chi-Ming
Published: December 2005

We evaluated the hypothesis that mechanical deformation of airway smooth muscle induces structural remodeling of airway smooth muscle cells, thereby modulating mechanical performance in subsequent contractions. This hypothesis implied that past experience of mechanical deformation was retained (or "memorized") as structural changes in airway smooth muscle cells, which modulated the cell's subsequent contractile responses. We termed this phenomenon mechanical strain memory. Preshortening has been found to induce attenuation of both force and isotonic shortening velocity in cholinergic receptor-activated airway smooth muscle. Rapid stretching of cholinergic receptor-activated airway smooth muscle from an initial length to a final length resulted in post-stretch force and myosin light chain phosphorylation that correlated significantly with initial length. Thus post-stretch muscle strips appeared to retain memory of the initial length prior to rapid stretch (mechanical strain memory). Cytoskeletal recruitment of actin- and integrin- binding proteins and Erk 1/2 MAPK appeared to be important mechanisms of mechanical strain memory. Sinusoidal length oscillation led to force attenuation during oscillation and in subsequent contractions in intact airway smooth muscle, and p38 MAPK appeared to be an important mechanism. In contrast, application of local mechanical strain to cultured airway smooth muscle cells induced local actin polymerization and cytoskeletal stiffening. It is conceivable that deep inspiration-induced bronchoprotection may be a manifestation of mechanical strain memory such that mechan ical deformation from past breathing cycles modulated the mechanical performance of airway smooth muscle in subsequent cycles in a continuous and dynamic manner.Key words: airway, cytoskeleton, deep inspiration, mechanics, smooth muscle.
Stretch-dependent growth and differentiation in vascular smooth muscle: role of the actin cytoskeleton
Authors: Hellstrand Per , Albinsson Sebastian
Published: December 2005

The smooth muscle cells in the vascular wall are constantly exposed to distending forces from the intraluminal pressure. A rise in blood pressure triggers growth of the vessel wall, which is characterized primarily by hypertrophy of smooth muscle cells with maintained differentiation in a contractile phenotype. Growth factor stimulation of dissociated smooth muscle cells, on the other hand, causes proliferative growth with loss of contractility. This type of response is also found in neointima development following angioplasty and in atherosclerotic lesions. An intact tissue environment is therefore critical for preserved differentiation. Recent advances point to a role of actin polymerization in the expression of smooth muscle differentiation marker genes, in concert with serum response factor (SRF) and cofactors, such as myocardin. Stretch of intact venous smooth muscle activates Rho and inhibits the actin filament severing factor cofilin, resulting in increased actin polymerization. Concomitantly, the rates of synthesis of SRF-regulated differentiation markers, such as SM22α, calponin, and α-actin, are increased. This increase in differentiation signals is parallel with activation of the mitogen-activated protein (MAP) kinase pathway. Thus stretch-induced growth in a maintained contractile phenotype occurs by dual activation of signal pathways regulating both growth and differentiation. A current challenge is to identify sites of crosstalk between these pathways in intact smooth muscle tissue.Key words: stretch, hypertension, ERK, Rho, caveolae.
The control of vascular smooth muscle function: My life-long learning and continuous discovery with Professor E.E. Daniel
Authors: Kwan Chiu-Yin
Published: December 2005

This communication is neither a comprehensive review of my research, nor a description about my recent new original scientific findings in smooth muscle or in cell Ca2+. For that intention, I will choose to publish via a regular channel, certainly not in this special edition. My intention is to take this opportunity to recapitulate Dr. Daniel's thoughts and spirits through the progress of my research, teaching, and personal development at McMaster University, stemming largely from Dr. Daniel's life-long interest in the regulation of Ca2+in the control of smooth muscle function, specifically the vascular smooth muscle. Being a culturally adsorbent person, I am sure that my thoughts and behavior must have been substantially influenced by Dr. Daniel over 27 years of our collaboration. His influence may have molded me into whom and what I am today, both socially and scientifically. Equally, I may also have influenced him in some particular or peculiar way. Dr. Daniel's academic contribution is globally well known for, but not limited to, his insightful and productive research in smooth muscle, but also for his effective application of problem-based learning to education in pharmacology and his influence on students and colleagues.Key words: vascular biology, smooth muscle, endothelial cell, calcium regulation, herbal pharmacology, hypertension, problem-based learning.
Fifty-eight years in science – a commentary
Authors: Daniel Edwin E
Published: December 2005

After 58 years in science, mostly in pharmacology, one gains perspective. Mine is that there have been important changes over this time, some good and some questionable. In this commentary, I try to reveal how I got to this stage, partially explaining my biases, and possibly helping others learn from my experiences including mistakes. Changing from seeking an M.D. to cellular biology and then to pharmacology early in my career were the best moves I made. The next best move was migration to Canada, away from the McCarthy-McCarran hysteria. Arriving at a time after the end of World War II when science in Canada was expanding was very good luck. I had an excellent opportunity to enjoy both the administration (as Chair of the first independent Department of Pharmacology at the University of Alberta) and the practice of pharmacology (as a practitioner of research on smooth muscle in health and disease). For me, the practice of research has always won over administration when a choice had to be made. Early on, I began to ask questions about educational practices and tried to evaluate them. This led me to initiate changes in laboratories and to seek nondidactic educational approaches such as problem-based learning. I also developed questions about the practice of anonymous peer review. After moving to McMaster in 1975, I was compelled to find a solution for a failed "Pharmacology Program" and eventually developed the first "Smooth Muscle Research Program". Although that was a good solution for the research component, it did not solve the educational needs. This led to the development of "therapeutic problems", which were used to help McMaster medical students educate themselves about applied pharmacology. Now these problems are being used to educate pharmacology honours and graduate students at the University of Alberta. The best part of all these activities is the colleagues and friends that I have interacted with and learned from over the years, and the realization that many of them have collaborated with me again in this volume.Key words: bias and anonymity, problem-based learning, research versus administration, smooth muscle.
Actin cytoskeletal dynamics in smooth muscle contraction
Authors: Gerthoffer William T
Published: December 2005

Smooth muscles develop isometric force over a very wide range of cell lengths. The molecular mechanisms of this phenomenon are undefined, but are described as reflecting "mechanical plasticity" of smooth muscle cells. Plasticity is defined here as a persistent change in cell structure or function in response to a change in the environment. Important environmental stimuli that trigger muscle plasticity include chemical (e.g., neurotransmitters, autacoids, and cytokines) and external mechanical signals (e.g., applied stress and strain). Both kinds of signals are probably transduced by ionic and protein kinase signaling cascades to alter gene expression patterns and changes in the cytoskeleton and contractile system. Defining the signaling mechanisms and effector proteins mediating phenotypic and mechanical plasticity of smooth muscles is a major goal in muscle cell biology. Some of the signaling cascades likely to be important include calcium-dependent protein kinases, small GTPases (Rho, Rac, cdc42), Rho kinase, protein kinase C (PKC), Src family tyrosine kinases, mitogen-activated protein (MAP) kinases, and p21 activated protein kinases (PAK). There are many potential targets for these signaling cascades including nuclear processes, metabolic pathways, and structural components of the cytoskeleton. There is growing appreciation of the dynamic nature of the actin cytoskeleton in smooth muscles and the necessity for actin remodeling to occur during contraction. The actin cytoskeleton serves many functions that are probably critical for muscle plasticity including generation and transmission of force vectors, determination of cell shape, and assembly of signal transduction machinery. Evidence is presented showing that actin filaments are dynamic and that actin-associated proteins comprising the contractile element and actin attachment sites are necessary for smooth muscle contraction.Key words: integrin, muscle mechanics, paxillin, Rho, HSP27.
Plasticity in airway smooth muscle: an update
Authors: Ford Lincoln E
Published: December 2005

At a similar meeting 10 years ago, we proposed (i) that the long functional range of some smooth muscles is accommodated by plastic alterations that place more myofilaments in series at longer lengths, (ii) that this plasticity is facilitated by myosin filament evanescence, with filaments dissociating partially during relaxation and reforming upon activation, and (iii) that filament lengthening during the rise of activation would cause velocity to fall. Since that meeting, we have accumulated a substantial body of evidence to support these proposals, as follows: (i) muscles develop nearly the same force when adapted to a range of lengths that can vary by 3-fold; (ii) other physiological parameters including shortening velocity, maximum power, compliance, ATPase rate, and thick-filament mass increase by about 2/3 for a doubling of muscle length; (iii) thick-filament density increases substantially during the rise of activation; and (iv) velocity falls as force rises during the rise of tetanic force, and when correction is made for differences in activation, velocity and force vary exactly in inverse proportion. This review explains the rationale for the different experimental measurements and their interpretation.Key words: muscle activation, series-to-parallel transition, myofilaments, myosin.
Isotonic relaxation of control and sensitized airway smooth muscle
Authors: Stephens N L , Fust A , Jiang H , Li W , Ma X
Published: December 2005

Smooth muscle relaxation has most often been studied in isometric mode. However, this only tells us about the stiffness properties of the bronchial wall and thus only about wall capacitative properties. It tells us little about airflow. To study the latter, which of course is the meaningful parameter in regulation of ventilation and in asthma, we studied isotonic shortening of bronchial smooth muscle (BSM) strips. Failure of BSM to relax could be another important factor in maintaining high airway resistance. To analyze relaxation curves, we developed an index of isotonic relaxation, t1/2(P, lCE), which is the half-time for relaxation that is independent of muscle load (P) and of initial contractile element length (lCE). This index was measured in curves of relaxation initiated at 2 s (normally cycling crossbridges) and at 10 s (latch-bridges). At 10 s no difference was seen for adjusted t1/2(P, lCE) between curves obtained from control and sensitized BSM, (8.38 ± 0.92 s vs. 7.78 ± 0.93 s, respectively). At 2 s the half-time was almost doubled in the sensitized BSM (6.98 ± 0.01 s (control) vs. 12.74 ± 2.5 s (sensitized)). Thus, changes in isotonic relaxation are only seen during early contraction. Using zero load clamps, we monitored the time course of velocity during relaxation and noted that it varied according to 3 phases. The first phase (phase i) immediately followed cessation of electrical field stimulation (EFS) at 10 s and showed almost the same velocity as during the latter 1/3 of shortening; the second phase (phase ii) was linear in shape and is associated with zero load velocity, we speculate it could stem from elastic recoil of the cells' internal resistor; and the third phase (phase iii) was convex downwards. The zero load velocities in phase iii showed a surprising spontaneous increase suggesting reactivation of the muscle. Measurements of intracellular calcium (Fura-2 study) and of phosphorylation of the 20 kDa myosin light chain showed simultaneous increments, indicating phase iii represented an active process. Studies are under way to determine what changes occur in these 3 phases in a sensitized muscle. And of course, in the context of this conference, just what role the plastic properties of the muscle play in relaxation requires serious consideration.Key words: airway smooth muscle, sensitized smooth muscle, isotonic relaxation, intracellular calcium transients, myosin light chain (20 kDa) phosphorylation.
The effects of body state on nest sanitation and provisioning effort in breeding barn swallows (Hirundo rustica)
Authors: Spencer K A
Published: December 2005

Parent birds feeding young are faced with a trade-off between allocating time and allocating energy to many variables, all of which will influence fitness to some degree. Here I use a novel experimental approach to determine the importance of nest sanitation and nest provisioning as components of reproductive effort in female barn swallows (Hirundo rustica L., 1758) feeding nestlings aged 11–15 days. Female birds were warmed overnight to allow extra energy at dawn and the short-term consequences for reproductive behaviour were determined upon release. Faecal sac removal rates were significantly positively related to nest visitation rates and warmed females showed a nonsignificant trend towards elevated sanitation behaviour. Females also showed a highly significant increase in nest visitation rates in response to the warming treatment compared with the controls. Precipitation had a significant negative effect on provisioning behaviour across all treatments. Nestling swallows were observed ejecting faecal sacs from the nest without parental help, and this precipitated a very low rate of faecal sac removal. The results suggest that nest sanitation may be an opportunistic behaviour in swallows and that it may not be an important component of reproductive effort in birds with older nestlings. The results also suggest a trade-off between nest sanitation and nest provisioning.
Overcoming environmental and morphological constraints: egg size and pelvic kinesis in the smallest tortoise, Homopus signatus
Authors: Hofmeyr M D , Henen B T , Loehr V J.T
Published: December 2005

The small tortoises of southern Africa include the only testudinid taxa that produce single-egg clutches. This group includes the world's smallest tortoise, Homopus signatus (Gmelin, 1789), which inhabits a harsh, arid environment. Climate and body size may influence reproductive output, so we hypothesized that the east–west aridity gradient in southern Africa affects egg and clutch size of the small indigenous tortoises, and that the morphology of H. signatus constrains egg size, preventing the formation of optimal eggs. Here we show that aridity and unpredictable rainfall determine which of these tortoise taxa produce single-egg clutches. Taxa in less predictable environments produce larger eggs relative to body size than do taxa in more predictable environments. Homopus signatus produces the largest egg relative to body size, probably to enhance offspring survival in its harsh environment. Body size, pelvic aperture size, and the narrow anal gap of H. signatus appear to constrain egg size. Despite these constraints, females produce rigid-shelled eggs larger than the pelvic canal and use pelvic kinesis to pass eggs at oviposition; both features are unknown in other chelonians and emphasize the selective advantage of large eggs to H. signatus.
Specialization and development of beach hunting, a rare foraging behavior, by wild bottlenose dolphins (Tursiops sp.)
Authors: Sargeant B L , Mann J , Berggren P , Krützen M
Published: December 2005

Foraging behaviors of bottlenose dolphins vary within and among populations, but few studies attempt to address the causes of individual variation in foraging behavior. We examined how ecological, social, and developmental factors relate to the use of a rare foraging tactic by wild bottlenose dolphins (Tursiops sp. Gervais, 1855) in Shark Bay, Western Australia. Beach hunting involves partial and nearly complete stranding on beach shores. Over 10 years of observation, only four adults and their calves were observed beach hunting in more than 1 year. Of two adult beach hunters observed in detail, one was more specialized in beach hunting than the other, indicating substantial flexibility in degree of use. Only calves born to beach hunters developed the tactic, although complete stranding was not observed at least up to 5 years of age. Beach hunters used shallow, inshore habitats significantly more than others and were more likely to hunt during incoming tide. Mitochondrial DNA haplotypes were not consistent with strict matrilineal transmission. Thus, beach hunting likely involves vertical social learning by calves, while individual, horizontal, and (or) oblique learning may occur among individuals who frequent coastal habitats.
Natal nutrition and the habitat distributions of male and female black-capped chickadees
Authors: Oort Harry van , Otter Ken A
Published: December 2005

In nonmigratory passerines, dispersing juveniles may compete to settle in suitable habitat patches, leading to phenotypic assortment across habitat types. We compared the past natal nutrition of 1st year black-capped chickadees (Poecile atricapillus (L., 1766)) that settled in two adjacent patches known to differ in suitability as breeding habitat: a mature mixed forest (good habitat) versus a young regenerating forest dominated by conifers (poor habitat). The past natal nutrition of recruits was estimated by measuring growth bars on their tail feathers grown as nestlings; growth bars were positively associated with body condition of birds at the time of capture, suggesting this measure may accurately reflect individual condition. Males that settled in either habitat had similar growth bar size; however, females that settled in the mature habitat had slightly larger growth bars than those in poor habitat. Individuals occupying the disturbed site were of similar size and in similar body condition compared with those that settled in the mature forest. These findings suggest that females may be more discriminating of habitat quality than males during natal dispersal, matching what is known about chickadee dispersal behaviour. We suggest that males are distributed with a non-ideal despotic distribution, whereas females are distributed with an ideal despotic distribution.
Stability of Jungck‐type iterative procedures
Authors: Singh S. L. , Bhatnagar Charu , Mishra S. N.
Published: December 2005

We introduce and discuss the stability of Jungck and Jungck‐Mann iterative procedures for a pair of Jungck‐Osilike‐type maps on an arbitrary set with values in a metric or linear metric space.