bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of a Contemporary Animal Model of Candida albicans-Associated Denture Stomatitis Using a Novel Intraoral Denture System
Authors: Johnson Clorinda C. , Yu Alika , Lee Heeje , Fidel Paul L. , Noverr Mairi C. 
Published: March 2012

ABSTRACT

Denture stomatitis (DS) is a fungal infection characterized by inflammation of the oral mucosa in direct contact with the denture and affects up to 50% of denture wearers. Despite the prevalence, very little is known about the role of fungal or host factors that contribute to pathogenesis. Recently, we developed a novel intraoral denture system for rodent research. This denture system consists of custom-fitted fixed and removable parts to allow repeated sampling and longitudinal studies. The purpose of this study was to use this denture system to develop a clinically relevant animal model of DS. To establish DS, rats were inoculated with pelleted
Candida albicans
, which resulted in sustained colonization of the denture and palate for 8 weeks postinoculation. Biofilm formation on the denture was observed by week 4 and on the palate by week 6 postinoculation. Rats were monitored for clinical signs of disease by assigning a clinical score after macroscopic examination of the palate tissue according to Newton's method. By week 4 postinoculation, the majority of inoculated rats with dentures exhibited a clinical score of 1 (pinpoint erythema). By week 6 and week 8 postinoculation, increasing percentages of rats exhibited a clinical score of 2 (diffuse erythema/edema). Histological analysis of palate tissue demonstrated progressively increasing inflammatory cell recruitment throughout the time course of the infection. Palatal biofilm formation was commensurate with development of palatal erythema, which suggests a role for biofilm in the inflammatory response.
Plasmodium falciparum Line-Dependent Association of
In Vitro
Growth-Inhibitory Activity and Risk of Malaria
Authors: Rono Josea , Färnert Anna , Olsson Daniel , Osier Faith , Rooth Ingegerd , Persson Kristina E. M. 
Published: March 2012

ABSTRACT

Plasmodium falciparum
's ability to invade erythrocytes is essential for its survival within the human host. Immune mechanisms that impair this ability are therefore expected to contribute to immunity against the parasite. Plasma of humans who are naturally exposed to malaria has been shown to have growth-inhibitory activity (GIA)
in vitro
. However, the importance of GIA in relation to protection from malaria has been unclear. In a case-control study nested within a longitudinally followed population in Tanzania, plasma samples collected at baseline from 171 individuals (55 cases and 116 age-matched controls) were assayed for GIA using three
P. falciparum
lines (3D7, K1, and W2mef) chosen based on their erythrocyte invasion phenotypes. Distribution of GIA differed between the lines, with most samples inhibiting the growth of 3D7 and K1 and enhancing the growth of W2mef. GIA to 3D7 was associated with a reduced risk of malaria within 40 weeks of follow-up (odds ratio, 0.45; 95% confidence interval [CI], 0.21 to 0.96;
P
= 0.04), whereas GIA to K1 and W2mef was not. These results show that GIA, as well as its association with protection from malaria, is dependent on the
P. falciparum
line and can be explained by differences in erythrocyte invasion phenotypes between parasite lines. Our study contributes knowledge on the biological importance of growth inhibition and the potential influence of
P. falciparum
erythrocyte invasion phenotypic differences on its relationship to protective immunity against malaria.
The Streptomycin-Treated Mouse Intestine Selects
Escherichia coli envZ
Missense Mutants That Interact with Dense and Diverse Intestinal Microbiota
Authors: Leatham-Jensen Mary P. , Frimodt-Møller Jakob , Adediran Jimmy , Mokszycki Matthew E. , Banner Megan E. , Caughron Joyce E. , Krogfelt Karen A. , Conway Tyrrell , Cohen Paul S. 
Published: March 2012

ABSTRACT

Previously, we reported that the streptomycin-treated mouse intestine selected nonmotile
Escherichia coli
MG1655
flhDC
deletion mutants of
E. coli
MG1655 with improved colonizing ability that grow 15% faster
in vitro
in mouse cecal mucus and 15 to 30% faster on sugars present in mucus (M. P. Leatham et al., Infect. Immun. 73:8039–8049, 2005). Here, we report that the 10 to 20% remaining motile
E. coli
MG1655 are
envZ
missense mutants that are also better colonizers of the mouse intestine than
E. coli
MG1655. One of the
flhDC
mutants,
E. coli
MG1655 Δ
flhD
, and one of the
envZ
missense mutants,
E. coli
MG1655 mot-1, were studied further.
E. coli
MG1655 mot-1 is more resistant to bile salts and colicin V than
E. coli
MG1655 Δ
flhD
and grows ca. 15% slower
in vitro
in mouse cecal mucus and on several sugars present in mucus compared to
E. coli
MG1655 Δ
flhD
but grows 30% faster on galactose. Moreover,
E. coli
MG1655 mot-1 and
E. coli
MG1655 Δ
flhD
appear to colonize equally well in one intestinal niche, but
E. coli
MG1655 mot-1 appears to use galactose to colonize a second, smaller intestinal niche either not colonized or colonized poorly by
E. coli
MG1655 Δ
flhD
. Evidence is also presented that
E. coli
MG1655 is a minority member of mixed bacterial biofilms in the mucus layer of the streptomycin-treated mouse intestine. We offer a hypothesis, which we call the “Restaurant” hypothesis, that explains how nutrient acquisition in different biofilms comprised of different anaerobes can account for our results.
Into the Eye of the Cytokine Storm
Authors: Tisoncik Jennifer R. , Korth Marcus J. , Simmons Cameron P. , Farrar Jeremy , Martin Thomas R. , Katze Michael G. 
Published: March 2012

SUMMARY
The cytokine storm has captured the attention of the public and the scientific community alike, and while the general notion of an excessive or uncontrolled release of proinflammatory cytokines is well known, the concept of a cytokine storm and the biological consequences of cytokine overproduction are not clearly defined. Cytokine storms are associated with a wide variety of infectious and noninfectious diseases. The term was popularized largely in the context of avian H5N1 influenza virus infection, bringing the term into popular media. In this review, we focus on the cytokine storm in the context of virus infection, and we highlight how high-throughput genomic methods are revealing the importance of the kinetics of cytokine gene expression and the remarkable degree of redundancy and overlap in cytokine signaling. We also address evidence for and against the role of the cytokine storm in the pathology of clinical and infectious disease and discuss why it has been so difficult to use knowledge of the cytokine storm and immunomodulatory therapies to improve the clinical outcomes for patients with severe acute infections.
Tissue-specific isotope trophic discrimination factors and turnover rates in a marine elasmobranch: empirical and modeling results
Authors: Malpica-Cruz Luis , Herzka Sharon Z. , Sosa-Nishizaki Oscar , Lazo Juan Pablo 
Published: March 2012

There are very few studies reporting isotopic trophic discrimination factors and turnover rates for marine elasmobranchs. A controlled laboratory experiment was conducted to estimate carbon and nitrogen isotope trophic discrimination factors and isotope turnover rates for blood, liver, muscle, cartilage tissue, and fin samples of neonate to young-of-the-year leopard sharks ( Triakis semifasciata ). Trophic discrimination factors varied (0.13‰–1.98‰ for δ13C and 1.08‰–1.76‰ for δ15N). Tissues reached or were close to isotopic equilibrium to the new diet after about a threefold biomass gain and 192 days. Liver and blood exhibited faster isotope turnover than muscle, cartilage tissue, and fin samples, and carbon isotopes turned over faster than those of nitrogen. Metabolic turnover contributed substantially to isotopic turnover, which differs from most reports for young marine teleosts. We modeled the relationship between muscle turnover rates and shark size by coupling laboratory results with growth rate estimates for natural populations. Model predictions for small, medium, and large wild leopard sharks indicate the time to isotopic equilibrium is from one to several years.
Development of an avidin sensor based on the poly(methoxy amino-β-styryl terthiophene)-coated glassy carbon electrode
Authors: Mehenni Hakim 
Published: March 2012

In this study, a simple and direct biosensor was proposed, which was based on biotin immobilized onto a conducting polymer-coated electrode, for the determination of avidin, a highly stable glycoprotein found in egg whites. Biotin was immobilized onto the electrode by covalent coupling to the primary amine group on poly-3′-(2-methoxy-5-amino-β-styryl)-(2,2′:5′,2″-terthiophene) (PMAST), and the biotin–avidin interaction was monitored by square-wave voltammetry. Incubation of the PMAST/biotin-modified coated electrode with avidin in a phosphate-buffered saline solution caused a significant change to its square-wave voltammogram, which was explained by the binding of avidin by biotin, and resulted in restricted ion transfer to and from the conducting polymer. This change was then utilized to determine avidin. Importantly, we found a linear relationship for the avidin sensor in the range of 4 × 10−14to 3 × 10−4mol/L, and the detection limit was determined to be approximately 10−14mol/L.
Microsatellite DNA analysis of parapatric lamprey (Entosphenusspp.) populations: implications for evolution, taxonomy, and conservation of a Canadian endemic
Authors: Taylor Eric B. , Harris Les N. , Spice Erin K. , Docker Margaret F. 
Published: March 2012

Parapatric freshwater and anadromous parasitic lampreys (Petromyzontiformes) from southwestern Vancouver Island, British Columbia, have been described as distinct taxa (Vancouver lamprey ( Entosphenus macrostomus (Beamish, 1982)) and Pacific lamprey ( Entosphenus tridentatus (Richardson, 1836)), respectively), using morphology, life history, and physiology. We tested for genetic differentiation at microsatellite DNA loci between these taxa and similar freshwater parasitic lampreys from two other lakes. The number of alleles and expected heterozygosity averaged 3.8 and 0.50, respectively, across loci and populations, and anadromous populations were more variable than freshwater populations. Population subdivision was moderate (FST = 0.096, P < 0.001) and 3% of the total variation was found between taxa and 1.7% was found among populations within taxa (both P < 0.001). Parapatric freshwater and anadromous parasitic lampreys separated by a maximum of 40 km were more distinct (mean FST = 0.042) than were anadromous populations located 800 km from one another (mean FST = 0.012). Localities within lakes with parasitic freshwater lampreys, however, showed little differentiation (FST = 0.0–0.08). Our data support recognizing E. macrostomus and E. tridentatus as distinct species, but similar levels of differentiation between these taxa and other freshwater parasitic lampreys suggest a species complex where the taxonomy remains unclear.
Small reserves around hibernation sites may not adequately protect mobile snakes: the example of Great Basin Gophersnakes (Pituophis catenifer deserticola) in British Columbia
Authors: Williams K.E. , Hodges K.E. , Bishop C.A. 
Published: March 2012

A common strategy for reptile conservation is to establish reserves around nesting or hibernation sites. The government of British Columbia, Canada, mandates protection of 200–300 ha wildlife habitat areas (WHAs) around hibernation sites of the federally threatened Great Basin Gophersnakes ( Pituophis catenifer deserticola Stejneger, 1893), but practical constraints result in a mean size of 193 ha. To evaluate the efficacy of this reserve size, we radio-tracked 39 adult Gophersnakes at four study sites in the Okanagan Valley in 2006 and 2007. Home ranges averaged 10.5 ± 1.7 ha. The maximum distance traveled from a hibernation site was 2400 m, whereas the maximum distance dispersed averaged 520 ± 65 m. An idealized circular WHA of 193 ha with the hibernation site at the centre would be large enough to contain Gophersnake home ranges, but the dispersal data show that only 85% of snakes would stay within that area. Small or asymmetrical WHAs likely protect even fewer Gophersnake locations. We recommend that WHAs be expanded if possible because the high mobility of Gophersnakes suggests that current reserves may not offer adequate protection.
Multiple captures of fulvous harvest mice (Reithrodontomys fulvescens) and northern pygmy mice (Baiomys taylori): evidence for short-term co-traveling
Authors: Green N.S. , Early C.E. , Beard L.K. , Wilkins K.T. 
Published: March 2012

Multiple captures of small mammals (finding >1 animal in a single trap) are often used to infer pair-bonding activity in arvicoline and cricetine rodents. We analyzed data from a 2-year trapping study to determine whether fulvous harvest mice ( Reithrodontomys fulvescens J.A. Allen, 1894) and (or) northern pygmy mice (Baiomys taylori (Thomas, 1887)) travel in mixed-sex mated pairs. A significant majority of multiple capture events (MCEs) in R. fulvescens were mixed-sex, whereas sex composition of pairs in B. taylori did not differ from random. Multiple capture probability was significantly positively related to abundance and unrelated to sex ratio in both species. Multiple captures of B. taylori were more common in winter, suggesting that individuals may associate to huddle for warmth. Masses of singly captured and multiply captured individuals were not significantly different in either species, contraindicating trap bias. Only one co-captured mixed-sex pair was recaptured as a pair (in R. fulvescens) and several animals of both sexes in both species were co-captured with multiple individuals. We concluded that R. fulvescens co-travels with mates for variable lengths of time, but we found no evidence that multiple captures of B. taylori are related to reproductive behavior.
Roost selection by the solitary, foliage-roosting hoary bat (Lasiurus cinereus) during lactation
Authors: Klug Brandon J. , Goldsmith Dayna A. , Barclay Robert M.R. 
Published: March 2012

Nests, roosts, and dens are an important facet of life for many animals and often provide refuge from weather and predators. Reproduction, particularly lactation, is energetically expensive. Many small mammals form maternity colonies in sheltered locations, which provides protection for offspring and mitigates the cost of staying warm. However, lasiurine bats give birth in roosts that superficially appear to offer relatively little thermal buffer. Given the consequences of a cold environment on offspring growth and the high energetic demand of thermoregulating and lactating concurrently, choosing roosts with certain microclimatic properties would be beneficial. We investigated the influence of microclimate on roost selection by lactating hoary bats ( Lasiurus cinereus (Beauvois, 1796)), a solitary foliage-roosting species. We found that roosts chosen by bats offered shelter from the wind and exposure to sunlight, and consistently had an opening that faced south. We suggest that lactating L. cinereus choose roosts based largely on a microclimate that reduces convective cooling and increases radiant heating, thereby mitigating the cost of thermoregulation and promoting rapid growth of offspring.
Space use and territoriality in swift foxes (Vulpes velox) in northeastern Colorado
Authors: Lebsock Amariah A. , Burdett Christopher L. , Darden Safi K. , Dabelsteen Torben , Antolin Michael F. , Crooks Kevin R. 
Published: March 2012

Space use is a fundamental characteristic that informs our knowledge of social relationships and the degree to which individuals are territorial. Until recently, relatively little was known about the spatial ecology and social organization of swift foxes ( Vulpes velox (Say, 1823)). We investigated space use of swift foxes on shortgrass prairie in northeastern Colorado. Our first objective was to evaluate sizes of seasonal and annual home ranges and core areas of 13 radio-collared swift foxes monitored continuously for 2 years. Our second objective was to compare home-range and core-area overlap of breeding pairs to that of neighboring foxes, including male–male, female–female, and nonbreeding female–male dyads. Home-range size in our study population was among the smallest previously reported for swift foxes. Males tended to have slightly larger home ranges and core areas than females, and home-range size was significantly larger in the breeding season than in both the pup-rearing and the dispersal seasons; sizes of core areas did not differ seasonally. Spatial overlap between breeding pairs was substantial, whereas spatial overlap between neighbors, particularly males, was low, suggesting territoriality.
Swimming performance and behaviour of young-of-the-year shortnose sturgeon (Acipenser brevirostrum) under fixed and increased velocity swimming tests
Authors: Deslauriers D. , Kieffer J.D. 
Published: March 2012

Swimming performance and behaviour in fish has been shown to vary depending on the investigation method. In this study, an endurance swimming curve was generated for young-of-the-year shortnose sturgeon (Acipenser brevirostrum LeSueur, 1818) (~7 cm total length, ~2 g) and compared with values determined in a separate incremental swimming (critical swimming, Ucrit) test. Using video, tail-beat frequency (TBF) was quantified and compared for fish swimming under both swimming tests. From the endurance-curve analysis, it was found that sturgeon did not display a statistically significant burst swimming phase. Maximum sustainable swimming speed (calculated to be 18.00 cm·s–1) from the endurance curve occurred at ~80% of Ucrit(22.30 cm·s–1). TBF was similar at all speeds for both swimming tests, except at speeds approaching Ucrit, where fish displayed TBFs of 4.29 Hz for the endurance protocol and 2.26 Hz for the Ucritprotocol. TBF was more variable between individuals swimming at the same speed within the Ucritcompared with the endurance protocol. Finally, a significant negative correlation was found between TBF and Ucritin individual fish, suggesting that station-holding may be an important energy saving strategy during swimming in this size class of sturgeon.
Geofluid behaviour in successive extensional and compressional events
Authors: Baqués V. , Travé A. , Roca E. , Marín M. , Cantarero I. 
Published: March 2012

The structural position of the Upper Jurassic–Lower Cretaceous carbonates located in the central part of the Catalan Coastal Ranges corresponds to the southwestern end of the Vallès-Penedès Fault. This fault was reactivated at different times during successive extensional and compressional events and several generations of fractures and cementations were formed.
Based on petrological and geochemical analyses of this cementation an evolution of the fluids related to the different tectonic stages can be deduced. (1) During the Mesozoic extension, the parent fluids resulted either from a mixing of trapped Upper Jurassic–Lower Cretaceous seawater and meteoric water, or from buffered meteoric waters. (2) Related to the Paleogene compression, the fluids came from the percolation of meteoric waters indicating shallow-depth deformation. (3) During the transitional phase between Paleogene compression and Neogene extension, a karstic dissolution took place and the porosities were infilled by different generations of sediments and cements deposited from meteoric fluids. (4) During the Neogene extension several episodes of meteoric percolations and fracturing processes occurred. The Neogene extensional faults used the earlier karstic system to develop and, later, during the late post-rift stage, a new karstic system occurred, covering the walls of open fractures with speleothems.
Bridge effect in charge transfer absorption bands of para‐substituted β‐nitrostyrenes
Authors: Morales Raúl G. E. , Vargas Victor , Hernández Carlos 
Published: March 2012

Charge transfer electronic transitions in a series of para‐substituted β‐nitro‐styrenes are analyzed in order to characterize the π‐conduction channel between the electron‐donor substituents and the NO2 electron‐acceptor group, particularly the bridge effect of the olefinic molecular structure.Absorption bands assignment of the π → π* electronic transitions in the near ultraviolet spectral region is carried out from an experimental and theoretical point of view. The photo‐induced charge transfer spectral bands of these aromatic compounds follow the same pattern as nitrobenzene, benzaldehyde and acetophenone and the electronic transition takes place in the π → π*(1La) excited state.Our present study based on ZINDO/S‐CIS M.O. calculations permits us to analyse the role of the NO2 electron‐acceptor group, and the ethylenic group, where this last structure merges as a second electron‐acceptor group. The calculated olefinic bridge molecular resistivities (ρo) of these β‐nitrostyrenes range from 2.1 to 2.5 (Å/quantum).
Cyclization reactions of IMM‐125 and oxidation of cyclosporin A amino‐acid 1 in the α position of the double bond lead to the loss of in vitro immunosuppressive activity
Authors: Dieden R. , Latinne D. , Baldari C. , Maton N. , Aubry A. , Verbeeck R. K. , Zurini M. , Lhoëst G. J. J. 
Published: March 2012

Cyclosporin A (CsA) and IMM‐125, a hydroxyethyl derivative of D‐serine CsA, are cyclic undecapeptides of molecular weight 1201.8 and 1261.8, respectively. The main metabolites still possessing the undecapeptide structure were found to be compounds resulting from the biotransformation of amino acids 4, 9 and 1.Under the influence of the hepatic cytochrome P‐450‐dependent monooxygenase system, CsA and IMM‐125 amino acid 1 are metabolized to a mono‐hydroxylated compound (metabolite M‐17) and to a dihydrodiol. A metabolite M18 was found to be the result of a non‐enzymic intramolecular formation of a tetrahydrofuran derivative from metabolite M17. Since the existence of a CsA dihydrodiol was reported and since epoxides are considered as the dihydrodiol precursors, the aim of the present work was to prove that the same non‐enzymic intramolecular formation of a tetrahydrofuran ring could occur by nucleophilic attack of the amino‐acid 1 β‐hydroxy group at the ɛ‐position of the freshly formed epoxide by reaction of IMM‐125 with m‐chloro‐perbenzoic acid and cyclosporin A with selenium oxide. The immunosuppressive activity of the compounds, as measured by the mixed lymphocyte reaction and by the luciferase activity of a Jurkat‐T‐cell line stably transfected with the NF‐AT/luc reporter plasmid, was found negligible for IMM‐125 compared to the parent drug as well as for the cyclosporin A derivative. Structures of the IMM‐125 and CsA derivatives were elucidated by electrospray mass‒spectrometry and NMR spectroscopy.