bluuebunny/crossref_metadata_2025 huggingface dataset:
Molecular Identification of
Aspergillus
Species Collected for the Transplant-Associated Infection Surveillance Network
Authors: Balajee S. Arunmozhi , Kano Rui , Baddley John W. , Moser Stephen A. , Marr Kieren A. , Alexander Barbara D. , Andes David , Kontoyiannis Dimitrios P. , Perrone Giancarlo , Peterson Stephen , Brandt Mary E. , Pappas Peter G. , Chiller Tom
Published: August 2009

A large aggregate collection of clinical isolates of aspergilli (
n
= 218) from transplant patients with proven or probable invasive aspergillosis was available from the Transplant-Associated Infection Surveillance Network, a 6-year prospective surveillance study. To determine the
Aspergillus
species distribution in this collection, isolates were subjected to comparative sequence analyses by use of the internal transcribed spacer and β-tubulin regions.
Aspergillus fumigatus
was the predominant species recovered, followed by
A. flavus
and
A. niger
. Several newly described species were identified, including
A. lentulus
and
A. calidoustus
; both species had high in vitro MICs to multiple antifungal drugs.
Aspergillus tubingensis
, a member of the
A. niger
species complex, is described from clinical specimens; all
A. tubingensis
isolates had low in vitro MICs to antifungal drugs.
Streptococcus pneumoniae
DNA Load in Blood as a Marker of Infection in Patients with Community-Acquired Pneumonia
Authors: Peters Remco P. H. , de Boer Richard F. , Schuurman Tim , Gierveld Sonja , Kooistra-Smid Mirjam , van Agtmael Michiel A. , Vandenbroucke-Grauls Christina M. J. E. , Persoons Maike C. J. , Savelkoul Paul H. M.
Published: August 2009

Direct detection of
Streptococcus pneumoniae
DNA in blood adds to culture results in the etiological diagnosis of patients with community-acquired pneumonia (CAP). Quantification of the amount of DNA, the bacterial DNA load (BDL), provides a measurement of DNAemia that may increase the understanding of the clinical relevance of
S. pneumoniae
DNA in blood. We evaluated the
S. pneumoniae
BDL as a diagnostic tool in adult patients with CAP. The BDL was determined in whole-blood samples collected simultaneously with blood for culture from 45 adult patients with CAP. After DNA extraction,
S. pneumoniae
DNA was detected with specific real-time PCR amplification, and the BDL was calculated with a standard curve. PCR and microbiological results were compared, and the BDL was related to clinical and laboratory parameters.
S. pneumoniae
DNA was detected in 10/13 patients with positive blood cultures and in 67% of patients with microbiologically confirmed pneumococcal pneumonia. The positive predictive values of the receiver operating characteristic curves for the BDLs for pneumococcal infection (100%) and pneumococcal bacteremia (69%) were higher than those for the level of C-reactive protein (CRP; 43% and 23%, respectively) and the white blood cell count (WBC; 42% and 35%, respectively); the negative predictive values of these three parameters were in the same range (±90 and ±97%, respectively). The BDL was higher in patients presenting with systemic inflammatory response syndrome and in patients with bacteremia. Positive correlations were observed for the BDL with WBC, CRP level, and length of stay. We conclude that the BDL supports the diagnosis of
S. pneumoniae
infection in patients with CAP and provides a putative marker of the severity of disease.
Bovine viral diarrhea virus proteins: relatedness of p175 with p80 and p125 and evidence of glycoprotein processing
Authors: Deregt Dirk , Masri Saad A. , Cho Hyun J. , Ohmann Helle Bielefeldt
Published: August 2009

Three monoclonal antibodies, which recognized two nonoverlapping antigenic domains and were reactive to the bovine viral diarrhea virus (BVDV) p80 protein, were found to cross react with the p125 protein of both cytopathic and noncytopathic BVDVs and a molecular weight 175 000 BVDV protein (p175). Results from limited proteolysis and chemical cleavage experiments confirmed the relatedness of these three proteins. In pulse-chase experiments it was apparent that p175 was a transient protein, as it was diminished during the chase, with a half-life of about 30 min. However, both p125 and p80 were also observed in short-pulsed lysates. Furthermore, during the chase, radiolabel was not found to accumulate into p125 or p80. Rather, these two proteins were stable with half-lives greater than 2 h. A fourth nonglycosylated protein, p37, increased during the chase. Processing of several glycoproteins was evident in these experiments. A glycoprotein of molecular weight 75 000 (gp75) diminished during the chase period, while glycoproteins gp62, gp48, and gp25 appeared or increased during the chase period. In contrast, the glycoprotein gp53 was a major protein in pulse-labeled cell lysates and remained constant throughout the chase period. In further experiments two stable forms of p80 differing in intramolecular disulphide bonding were observed. Key words: bovine viral diarrhea virus, proteins, relationships and processing, monoclonal antibodies.
Numbers, activities, and diversity of autotrophic ammonia-oxidizing bacteria in a freshwater, eutrophic lake sediment
Authors: Smorczewski W. T. , Schmidt E. L.
Published: August 2009

The microbiological and chemical potential for ammonia oxidation in a freshwater, eutrophic lake sediment was examined in relation to environmental changes caused by seasonal, dimictic circulation. Poulations of both ammonia and nitrite oxidizers as estimated by most probable number (MPN) were sustained throughout extended anaerobic summer intervals, with nitrite oxidizers outnumbering ammonia oxidizers by a factor ranging from 3.0 to 8.1. Ammonia oxidation potential on a per cell basis was affected by seasonal changes and was seen to decrease as oxygen was removed from the sediments. Pure-culture isolations from a positive MPN tube inoculated with oxygenated sediment and representing a single point in a seasonal cycle produced ammonia-oxidizing strains belonging to the genus Nitrosospira. These strains did not react with known ammonia-oxidizer serotypes and, therefore, extend the serological diversity of this group of bacteria. An immunofluorescence analysis of MPN tubes from sediment collected during a period of lake stratification revealed progressive changes in the diversity of the ammonia-oxidizer population. The genera Nitrosomonas, Nitrosolobus, and Nitrosospira, including the novel serotype of Nitrosospira isolated from the sediment a year earlier, were found to coexist in well-oxygenated sediment. This diversity was seen to disappear, with Nistrosomonas surviving, as anaerobic conditions persisted. Key words: ammonia oxidizers, lake sediments, nitrifiers, nitrification.
Susceptibility of congenitally immunodeficient mice to a nonencapsulated strain of Cryptococcus neoformans
Authors: Salkowski Cindy A. , Balish Edward
Published: August 2009

The susceptibility of congenitally immunodeficient mice to a nonencapsulated strain of Cryptococcus neoformans (strain M7) was evaluated. Gnotobiotic mice with defined congenital defects in innate immunity (beige) or cell-mediated immunity (athymic) or with combined defects in innate and cellular immunity (beige athymic) were i.v. challenged with C. neoformans M7. The nonencapsulated strain of C. neoformans produced a persistant low-grade infection in the brains of all immunodeficient and immunocompetent mice used in this study. Immunocompetent mice (nu/+;bg/+) and immunodeficient bg/bg mice readily cleared nonencapsulated cryptococci from their kidneys, liver, lungs, and spleen. In contrast to nu/+ mice, nu/nu mice had a reduced capacity to clear nonencapsulated cryptococci from their kidneys and liver after i.v. challenge. Both bg/bg–nu/nu and bg/bg–nu/+ mice developed a low-grade infection in their kidneys, liver, lungs, and spleen, which was maintained throughout the 21-day study. Persistent infections were not due to reversion to an encapsulated state. These data indicate that a capsule may not always be necessary for C. neoformans to survive, in vivo, in tissues of immunodeficient and immunocompetent mice. Key words: Cryptococcus neoformans, capsule, immunodeficient mice.
Changes in rates of synthesis of individual proteins in a psychrophilic bacterium after a shift in temperature
Authors: Araki Tadashi
Published: August 2009

In the psychrophilic bacterium Vibrio sp. strain ANT-300, which has the ability to grow efficiently between 13 and −2 °C, with an optimum at 7 °C, cells in steady-state growth at 0 and 13 °C appeared to exhibit different patterns in the levels of certain individual proteins. With a shift in temperature, the steady-state level of individual proteins was achieved only after dramatic transient changes in the rates of synthesis of a small number of those proteins whose levels would be adjusted. Upon a shift up from 0 to 13 °C, the rates of synthesis of at least 25 proteins increased transiently, while increased rates of synthesis of 39 proteins were induced immediately upon a shift down from 13 to 0 °C. The proteins of which the levels would be adjusted were synthesized at differential rates, which varied conspicuously with respect to timing after the shifts in temperature. Such changes appear to be active regulatory responses to changes in temperature. Key words: psychrophile, Vibrio sp. strain ANT-300, heat-shock proteins, cold-shock proteins.
A zinc-binding protein in a metal-resistant strain, Alcaligenes eutrophus CH34
Authors: Remacle J. , Vercheval C.
Published: August 2009

Synthesis of a zinc-binding protein was induced when Alcaligenes eutrophus CH34 was grown in the presence of high concentrations of zinc (2.3 mM). The zinc-binding protein has a low content of cysteine and a high content of acidic amino acids and, thus, differs from metallothionein. Key words: Alcaligenes eutrophus CH34, metal-binding protein, zinc.
Assessment of two commercial agglutination kits for detecting Escherichia coli heat-labile enterotoxin
Authors: Speirs J. , Stavric S. , Buchanan B.
Published: August 2009

Two commercial agglutination kits, a reserved passive agglutination test (VET-RPLA) and a staphylococcal coagglutination test (Phadebact ETEC-LT Test), were compared with two cell culture assays (Y-1 and Vero) and GM1 ganglioside enzyme-linked immunosorbent assay (GM1-ELISA) for sensitivity in detecting Escherichia coli heat-labile enterotoxin (LT). Of 48 toxigenic strains, 23 were positive by all assays. One strain was negative only by the Phadebact test. Four strains, all LT-II producers, were positive by cell culture only. For LT-I detection, the Phadebact test was the least sensitive but was simple and rapid; VET-RPLA was simple, sensitive, and a good substitute for cell culture or GM1-ELISA. Key words: Escherichia coli, heat-labile enterotoxin, agglutination kits.
Location-allocation models for one-strike initial attack of forest fires by airtankers
Authors: Hodgson M. J. , Newstead R. G.
Published: August 2009

This paper presents and compares two location-allocation models for assigning a limited number of airtanker groups among a larger number of potential bases. Model I selects bases to maximize the number of fires (weighted by value at risk) within range of an attack base. Model II trades off this goal with the minimization of mean fire to base distance. The models were applied to 1971–1974 fire totals in Alberta for three 10-day periods. As the number of airtanker groups was increased from one to the maximum, the performance of each model increased with smoothly diminishing returns. For all periods and at most levels of resource investment, the maximum coverage model served only a few more fires than did the other, sacrificing considerable distance in doing so. In view of the limitations of these simple models, a more comprehensive model was developed and discussed.
Phytotoxicity of fenitrothion to white pine seeds and seedlings
Authors: Weinberger Pearl , Pomber L. , Prasad R.
Published: August 2009

Seeds of white pine (Pinusstrobus L.) were stratified in water or a water–fenitrothion emulsion. Two concentrations of fenitrothion were used: 10ppm (equivalent to an approved field concentration) and 1000 ppm. Some toxicological changes were associated with the higher concentration of fenitrothion alone, others were associated with both concentrations of the insecticide. More water was imbibed by seeds treated with 1000 ppm and the amounts and distribution of basic proteins were mainly changed at the higher level of fenitrothion exposure. Cytological studies indicated that succinic dehydrogenases and the esterases were also affected by the lower field concentration of fenitrothion, especially in the hypocotyl region of the embryo. There was no apparent effect on the total insoluble polysaccharides or on DNA metabolism during the first 10 days of growth following either treatment. Although toxicological changes were associated with exposure to fenitrothion, no detrimental long-term effects were observed.
A Tsugaheterophylla – Piceasitchensis ecosystem of coastal Oregon: decomposition and nutrient balances of fallen logs
Authors: Grier Charles C.
Published: August 2009

Weight loss and changes in N, P, Ca, Mg, K, and Na content were determined for fallen Tsugaheterophylla (Raf.) Sarg. logs in a 121-year-old Tsugaheterophylla – Piceasitchensis (Bong) Carr. stand on the central Oregon coast. Log ages ranged from 2 to 38 years.Weights of fallen logs decreased in a roughly negative logarithmic pattern; after 38 years the average log had lost 34.5% of its original weight.Nitrogen, calcium, and magnesium contents of logs increased for about the first 20 years and declined thereafter. Phosphorus and potassium contents decreased steadily with age. Sodium content increased with age. Except for calcium, nutrient input to log surfaces by litterfall and throughfall was greater than any increases in nutrient content.
Dry matter accumulation by Piceasitchensis seedlings during winter
Authors: Bradbury Ian K. , Malcolm D. C.
Published: August 2009

Dry matter production by Sitka spruce seedlings (Piceasitchensis (Bong.) Carr) outside the period of shoot extension was determined in southern Scotland by harvesting plants from a nursery on 13 occasions between late September and mid-May. Air and soil temperature and incoming radiation were measured in an attempt to relate weight changes to climatic variables. Dry weight of the plants apparently doubled between late September and mid-April but subsequently changed little. Most dry weight increase occurred during October, late March, and April but there was also a slight increase in weight in midwinter. The relative increase in weight was similar in roots and shoots until mid-January but thereafter was proportionally much greater in shoots than in roots and was associated with a marked increase in needle weight. Lack of weight increase in late spring was attributed to the respiratory demands of bud expansion. Dry matter changes in the 12 harvest intervals was not related to mean daily temperature, incoming radiation, or photoperiod, but when averaged over periods of 1 month a much closer relationship was evident.
Effects of soil-applied potassium on cation distribution around wounds in red maple
Authors: Blanchard Robert O. , Smith Desmond , Shigo Alex L. , Safford L. O.
Published: August 2009

Cation levels around wounds were evaluated to determine rate of concentration and relation of net increase to availability following soil amendments.Forty trees in four clones of 6-year-old red maple (Acerrubrum L.) were paired by stem size. Half the clones were amended with soil-applied potassium chloride at 450 kg potassium/hectare. One tree of each pair was wounded and one pair of trees from each clone was harvested each week for 5 weeks. Concentrations of K, Mg, and Mn around wound sites and comparable sites on nonwounded trees were determined for each harvest. Concentrations of the three elements in wounded tissues increased significantly over the 5-week period. Addition of K to the soil did not appear to influence concentrations of Mg or Mn in either wounded or nonwounded tissues. Additions of K to the soil significantly increased concentrations of K in nonwounded tissues over controls, but concentrations in wounded tissues of both treated and nontreated trees were equivalent. This suggests that at least initial increases in K concentration in wounded tissues take place independent of uptake of K by trees from soil.
Container and root treatments affect growth and root form of planted ponderosa pine
Authors: Owston Peyton W. , Seidel K. W.
Published: August 2009

Field performance and root form of container-grown Pinnsponderosa Laws. seedlings were studied after application of three treatments and compared with untreated bare-root seedlings. One-year-old seedlings grown in 1.9-ℓ milk carton containers were treated by (1) removing the bottom of the container, (2) removing the whole container, and (3) removing the whole container and cutting spiralled roots off at the bottom of the surface of the root ball. Survival was excellent for trees of all treatments. Bare-root seedlings grew most in height the first season, but after 5 years, the average height of container seedlings was greater than for bare-root trees. Seedlings with container removed and roots cut were tallest and had root systems that appeared sturdiest. Most of these had well developed taproots and good outward growth of laterals with little spiralling. Aborted or kinked taproots and spiralled laterals were often found where only the bottom of the container had been removed.
Induction florale sur pousses d'août chez le Douglas (Pseudotsugamenziesii)
Authors: Bonnet-Masimbert Marc , Lanares René
Published: August 2009

Numerous and perfectly well developed seed cones appeared on lammas shoots of young Douglas-fir. In 1973, among 73 flowering grafted trees 6 years old, 76% of seed cones (i.e. 380) were associated with lammas shoots. In 1976, among 171 flowering seedling trees 8 years old, 83% of the seed cones (i.e. 762) were concerned with this phenomenon. A very dry period, interrupted by a few very rainy days, might be responsible for this. The theoretical incidence of this observation and its practical interest for manipulation on flowering induction are discussed.
NON-CONCAVE MULTIFRACTAL SPECTRA WITH WAVELET LEADERS PROJECTION OF SIGNALS WITH AND WITHOUT CHIRPS
Authors: CARDO ROMINA , CORVALÁN ALVARO
Published: August 2009

The multifractal spectrum has been revealed recently as a very useful tool for the analysis of signals, especially in those coming from the measurement of physical variables in chaotic or critical systems with multifractal structure, and in which many phenomena interact in multiple scales. In addition, in this context, the presence of singularities of rapid oscillation, chirps, is frequently difficult to handle. In this work we propose a way for using "wavelet leaders", avoiding the Legendre transform, for developing a new method capable of recognizing if a non-concave multifractal spectrum arises in a given signal, and is also capable of obtaining it in the case in which oscillating singularities appear, and so it succeeds where any other method fails.
A NEW CLASSIFICATION OF NON-OVERLAPPING SYMMETRIC BINARY FRACTAL TREES USING EPSILON HULLS
Authors: TAYLOR T. D.
Published: August 2009

This paper presents an analysis of non-overlapping symmetric binary fractal trees using methods of computational topology. In particular, we study the topological aspects of the epsilon-hulls of the trees as epsilon ranges over the non-negative real numbers. The complexity of a tree is defined in terms of the maximum range of the number of levels of holes that can be present for a given ∊. All self-contacting trees have infinite complexity, with the important exceptions of the self-contacting trees with branching angles 90° and 135° (which are space-filling). These two angles have been identified by Mandelbrot and Frame as being topologically critical, and our analysis provides further support to that claim. We will show that for trees with branching angles 90° or 135°, there is a finite upper bound to complexity. For all other branching angles there is no upper bound to complexity. Self-avoiding trees are topologically equivalent because they are all contractible. Our new definition of complexity provides a new way to compare self-avoiding trees.
EMPIRICAL TESTING OF MULTIFRACTALITY OF FINANCIAL TIME SERIES BASED ON WTMM
Authors: YALAMOVA ROSSITSA
Published: August 2009

The multifractal spectrum calculated with wavelet transform modulus maxima (WTMM) provides information on the higher moments of market returns distribution and the multiplicative cascade of volatilities. This paper applies a wavelet based methodology for calculation of the multifractal spectrum of financial time series. WTMM methodology provides a better measure of risk changes compared to the structure function approach. It is well founded in applied mathematics and physics with little popularity among finance researchers.
Transformation at Foster's (A), (B) and (C)
Authors: Lewis Geoffrey , Zalan Tatiana
Published: August 2009

Foster's Group is an Australia-based global alcoholic beverages company which produces a wide range of beer and wine. Case (A), set in February 2008, opens up with damning media reports, questioning the ability of Foster's CEO Trevor O'Hoy to deliver satisfying financial performance. The case then traces the evolution of Foster's Group, originally a beer company, and outlines its strategy of internationalisation (in North America, the U.K. and Asia) and corporate strategy based on diversifying acquisitions in wine. The case's focus is on the last two decades of Foster's growth under the leadership of two CEOs — Ted Kunkel and Trevor O'Hoy. Case (A) describes the difficulties Trevor O'Hoy experienced in integrating the acquisitions of Beringer (U.S.) and Southcorp (Australia) and pushing a "One Foster's" multi-beverage strategy.

Cases (B) and (C), set in June and July of 2008, provide follow-up information. Trevor O'Hoy resigns, and Foster's Board of Directors urgently needs to sort out the company's future strategy and succession.

The case allows the students to examine central issues in corporate and international strategy, namely internationalisation of a leading domestic company and issues of international acquisitions; corporate strategy, with a focus on diversifying acquisitions, post-merger integration and synergies; and corporate governance issues and the role of the Board in strategy.
On the Relation Between Schmidt Coefficients and Entanglement
Authors: Aniello Paolo , Lupo Cosmo
Published: August 2009

We consider the Schmidt decomposition of a bipartite density operator induced by the Hilbert-Schmidt scalar product, and we study the relation between the Schmidt coefficients and entanglement. First, we define the Schmidt equivalence classes of bipartite states. Each class consists of all the density operators (in a given bipartite Hilbert space) sharing the same set of Schmidt coefficients. Next, we review the role played by the Schmidt coefficients with respect to the separability criterion known as the 'realignment' or 'computable cross norm' criterion; in particular, we highlight the fact that this criterion relies only on the Schmidt equivalence class of a state. Then, the relevance — with regard to the characterization of entanglement — of the 'symmetric polynomials' in the Schmidt coefficients and a new family of separability criteria that generalize the realignment criterion are discussed. Various interesting open problems are proposed.
Remarks on the GNS Representation and the Geometry of Quantum States
Authors: Chruściński Dariusz , Marmo Giuseppe
Published: August 2009

It is shown how to introduce a geometric formulation of the algebraic approach to the standard non-relativistic quantum mechanics. It turns out that the GNS representation provides not only symplectic but even Hermitian realization of a 'quantum Poisson algebra'. We discuss alternative Hamiltonian structures emerging out of different GNS representations which provide a natural setting for quantum bi-Hamiltonian systems.
Quantum Criticality of Ground and Thermal States in XX Model
Authors: Son Wonmin , Vedral Vlatko
Published: August 2009

Here, we compare the critical behaviour of the ground state and the thermal state of the XX model. We analyze full energy spectra and the exact form of eigenstates to reconstruct the ground state and the thermally excited state. With the solutions, we discuss the properties of quantum phase transition at zero temperature as well as the state in a thermal equilibrium.
A Simple Thermodynamical Witness Showing Universality of Macroscopic Entanglement
Authors: Vedral Vlatko
Published: August 2009

We show that if the ground state entanglement exceeds the total entropy of a given system, then this system is in an entangled state. This is a universal entanglement witness that applies to any physical system and yields a temperature below which we are certain to find some entanglement. Our witness is then applied to generic bosonic and fermionic many-body systems to derive the corresponding "critical" temperatures that have a very broad validity.
Mechanisms Shaping the Membranes of Cellular Organelles
Authors: Shibata Yoko , Hu Junjie , Kozlov Michael M. , Rapoport Tom A.
Published: August 2009

Cellular organelles have characteristic morphologies that arise as a result of different local membrane curvatures. A striking example is the endoplasmic reticulum (ER), which consists of ER tubules with high curvature in cross-section, peripheral ER sheets with little curvature except at their edges and the nuclear envelope with low curvature except where the nuclear pores are inserted. The ER may be shaped by several mechanisms. ER tubules are often generated through their association with the cytoskeleton and stabilized by two families of integral membrane proteins, the reticulons and DP1/Yop1p. Similar to how curvature is generated in budding vesicles, these proteins may use scaffolding and hydrophobic insertion mechanisms to shape the lipid bilayer into tubules. In addition, proteins of the dynamin family may deform the ER membrane to generate a tubular network. Mechanisms affecting local membrane curvature may also shape peripheral ER sheets and the nuclear envelope as well as mitochondria and caveolae.
Conflicting Views on the Membrane Fusion Machinery and the Fusion Pore
Authors: Sørensen Jakob B.
Published: August 2009

Fast exocytosis of synaptic vesicles differs from other membrane fusion reactions by being under tight temporal control by the intracellular calcium concentration. This is achieved by subjecting the SNARE-dependent fusion pathway to additional layers of control, both upstream and downstream of the assembly of the fusogenic SNARE-complex. Here, I review conflicting views on the function of the core fusion machinery consisting of the SNAREs, Munc18, complexin, and synaptotagmin. Munc18 controls docking of vesicles to the plasma membrane and initial SNARE-complex assembly, whereas complexin and synaptotagmin cooperate in holding the SNARE complex in an intermediate release-ready or cocked state. Different effects of complexin and synaptotagmin shape the energy landscape for fusion and make final fusion calcium triggered. The final steps are fusion pore formation and expansion, which allow release of the water-soluble vesicle content. The fusion pore remains the most elusive part of the exocytosis pathway, owing to its short lifetime.
The Biogenesis and Function of PIWI Proteins and piRNAs: Progress and Prospect
Authors: Thomson Travis , Lin Haifan
Published: August 2009

The evolutionarily conserved Argonaute/PIWI (AGO/PIWI, also known as PAZ-PIWI domain or PPD) family of proteins is crucial for the biogenesis and function of small noncoding RNAs (ncRNAs). This family can be divided into AGO and PIWI subfamilies. The AGO proteins are ubiquitously present in diverse tissues. They bind to small interfering RNAs (siRNAs) and microRNAs (miRNAs). In contrast, the PIWI proteins are predominantly present in the germline and associate with a novel class of small RNAs known as PIWI-interacting RNAs (piRNAs). Tens of thousands of piRNA species, typically 24–32 nucleotide (nt) long, have been found in mammals, zebrafish, and Drosophila. Most piRNAs appear to be generated from a small number of long single-stranded RNA precursors that are often encoded by repetitive intergenic sequences in the genome. PIWI proteins play crucial roles during germline development and gametogenesis of many metazoan species, from germline determination and germline stem cell (GSC) maintenance to meiosis, spermiogenesis, and transposon silencing. These diverse functions may involve piRNAs and may be achieved via novel mechanisms of epigenetic and posttranscriptional regulation.
Orai1, a critical component of store-operated Ca2+entry, is functionally associated with Na+/Ca2+exchanger and plasma membrane Ca2+pump in proliferating human arterial myocytes
Authors: Baryshnikov Sergey G. , Pulina Maria V. , Zulian Alessandra , Linde Cristina I. , Golovina Vera A.
Published: August 2009

Ca2+entry through store-operated channels (SOCs) in the plasma membrane plays an important role in regulation of vascular smooth muscle contraction, tone, and cell proliferation. The C-type transient receptor potential (TRPC) channels have been proposed as major candidates for SOCs in vascular smooth muscle. Recently, two families of transmembrane proteins, Orai [also known as Ca2+release-activated Ca2+channel modulator (CRACM)] and stromal interacting molecule 1 (STIM1), were shown to be essential for the activation of SOCs mainly in nonexcitable cells. Here, using small interfering RNA, we show that Orai1 plays an essential role in activating store-operated Ca2+entry (SOCE) in primary cultured proliferating human aortic smooth muscle cells (hASMCs), whereas Orai2 and Orai3 do not contribute to SOCE. Knockdown of Orai1 protein expression significantly attenuated SOCE. Moreover, inhibition of Orai1 downregulated expression of Na+/Ca2+exchanger type 1 (NCX1) and plasma membrane Ca2+pump isoform 1 (PMCA1). The rate of cytosolic free Ca2+concentration decay after Ca2+transients in Ca2+-free medium was also greatly decreased under these conditions. This reduction of Ca2+extrusion, presumably via NCX1 and PMCA1, may be a compensation for the reduced SOCE. Immunocytochemical observations indicate that Orai1 and NCX1 are clustered in plasma membrane microdomains. Cell proliferation was attenuated in hASMCs with disrupted Orai1 expression and reduced SOCE. Thus Orai1 appears to be a critical component of SOCE in proliferating vascular smooth muscle cells, and may therefore be a key player during vascular growth and remodeling.
Attenuation of peripheral salt taste responses and local immune function contralateral to gustatory nerve injury: effects of aldosterone
Authors: Guagliardo Nick A. , West Katie Nicole , McCluskey Lynnette P. , Hill David L.
Published: August 2009

Dietary sodium restriction coupled with axotomy of the rat chorda tympani nerve (CTX) results in selectively attenuated taste responses to sodium salts in the contralateral, intact chorda tympani nerve. Converging evidence indicates that sodium deficiency also diminishes the activated macrophage response to injury on both the sectioned and contralateral, intact sides of the tongue. Because a sodium-restricted diet causes a robust increase in circulating aldosterone, we tested the hypothesis that changes in neurophysiological and immune responses contralateral to the CTX could be mimicked by aldosterone administration instead of the low-sodium diet. Taste responses in rats with CTX and supplemental aldosterone for 4–6 days were similar to rats with CTX and dietary sodium restriction. Responses to sodium salts were as much as 50% lower compared with sham-operated and vehicle-supplemented rats. The group-related functional differences were eliminated with lingual application of amiloride, suggesting that a major transduction pathway affected was through epithelial sodium channels. Consistent with the functional results, few macrophages were observed on either side of the tongue in rats with CTX and aldosterone. In contrast, macrophages were elevated on both sides of the tongue in rats with CTX and the vehicle. These results show that sodium deficiency or administration of aldosterone suppresses the immune response to neural injury, resulting in attenuation of peripheral gustatory function. They also show a potential key link among downstream consequences of sodium imbalance, taste function, and immune activity.
Hibernation induces pentobarbital insensitivity in medulla but not cortex
Authors: Hengen Keith B. , Behan Mary , Carey Hannah V. , Jones Mathew V. , Johnson Stephen M.
Published: August 2009

The 13-lined ground squirrel ( Ictidomys tridecemlineatus), a hibernating species, is a natural model of physiological adaption to an extreme environment. During torpor, body temperature drops to 0–4°C, and the cortex is electrically silent, yet the brain stem continues to regulate cardiorespiratory function. The mechanisms underlying selective inhibition in the brain during torpor are not known. To test whether altered GABAergic function is involved in regional and seasonal differences in neuronal activity, cortical and medullary slices from summer-active (SA) and interbout aroused (IBA) squirrels were placed in a standard in vitro recording chamber. Silicon multichannel electrodes were placed in cortex, ventral respiratory column (VRC), and nucleus tractus solitarius (NTS) to record spontaneous neuronal activity. In slices from IBA squirrels, bath-applied pentobarbital sodium (300 μM) nearly abolished cortical neuronal activity, but VRC and NTS neuronal activity was unaltered. In contrast, pentobarbital sodium (300 μM) nearly abolished all spontaneous cortical, VRC, and NTS neuronal activity in slices from SA squirrels. Muscimol (20 μM; GABAAreceptor agonist) abolished all neuronal activity in cortical and medullary slices from both IBA and SA squirrels, thereby demonstrating the presence of functional GABAAreceptors. Pretreatment of cortical slices from IBA squirrels with bicuculline (100 μM; GABAAreceptor antagonist) blocked pentobarbital-dependent inhibition of spontaneous neuronal activity. We hypothesize that GABAAreceptors undergo a seasonal modification in subunit composition, such that cardiorespiratory neurons are uniquely unaffected by surges of an endogenous positive allosteric modulator.
Effects of contraction on localization of GLUT4 and v-SNARE isoforms in rat skeletal muscle
Authors: Rose Adam J. , Jeppesen Jacob , Kiens Bente , Richter Erik A.
Published: August 2009

In skeletal muscle, contractions increase glucose uptake due to a translocation of GLUT4 glucose transporters from intracellular storage sites to the surface membrane. Vesicle-associated membrane proteins (VAMPs) are believed to play an important role in docking and fusion of the GLUT4 transporters at the surface membrane. However, knowledge about which VAMP isoforms colocalize with GLUT4 vesicles in mature skeletal muscle and whether they translocate during muscle contractions is incomplete. The aim of the present study was to further identify VAMP isoforms, which are associated with GLUT4 vesicles and examine which VAMP isoforms translocate to surface membranes in skeletal muscles undergoing contractions. VAMP2, VAMP3, VAMP5, and VAMP7 were enriched in immunoprecipitated GLUT4 vesicles. In response to 20 min of in situ contractions, there was a redistribution of GLUT4 (+64 ± 13%), transferrin receptor (TfR; +75 ± 22%), and insulin-regulated aminopeptidase (IRAP; +70 ± 13%) to fractions enriched in heavy membranes away from low-density membranes (−32 ± 7%; −18 ± 12%; −33 ± 9%; respectively), when compared with the resting contralateral muscle. Similarly, there was a redistribution of VAMP2 (+240 ± 40%), VAMP5 (+79 ± 9%), and VAMP7 (+79 ± 29%), but not VAMP3, to fractions enriched in heavy membranes away from low-density membranes (−49 ± 10%, −54 ± 9%, −14 ± 11%, respectively) in contracted vs. resting muscle. In summary, VAMP2, VAMP3, VAMP5, and VAMP7 coimmunoprecipitate with intracellular GLUT4 vesicles in muscle, and VAMP2, VAMP5, VAMP7, but not VAMP3, translocate to the cell surface membranes similar to GLUT4, TfR, and IRAP in response to muscle contractions. These findings suggest that VAMP2, VAMP5, and VAMP7 may be involved in translocation of GLUT4 during muscle contractions.
Role of mast cells and protease-activated receptor-2 in cyclooxygenase-2 expression in urothelial cells
Authors: Wang Zun-Yi , Wang Peiqing , Bjorling Dale E.
Published: August 2009

Mast cells have been shown to play a role in development and persistence of various inflammatory bladder disorders. Mast cell-derived tryptase specifically activates protease-activated receptor-2 (PAR-2), and PAR-2 is known to be involved in inflammation. We investigated whether mast cells participate in increase of cyclooxygenase-2 (COX-2) protein abundance in urothelium/suburothelium of bladders of mice subsequent to cyclophosphamide (CYP)-induced bladder inflammation. We also used primary cultures of human urothelial cells to investigate cellular mechanisms underlying activation of PAR-2 resulting in increased COX-2 expression. We found that treatment of mice with CYP (150 mg/kg ip) increased COX-2 protein abundance in bladder urothelium/suburothelium 3, 6, and 24 h after CYP ( P < 0.01), and increased COX-2 protein abundance was prevented by treatment of mice with the mast cell stabilizer sodium cromolyn (10 mg/kg ip) for 4 consecutive days before CYP treatment. Incubation of freshly isolated mouse urothelium/suburothelium with a selective PAR-2 agonist, 2-furoyl-LIGRLO-amide (3 μM), also increased COX-2 protein abundance ( P < 0.05). We further demonstrated that 2-furoyl-LIGRLO-amide (3 μM) increased COX-2 mRNA expression and protein abundance in primary cultures of human urothelial cells ( P < 0.01), and the effects of PAR-2 activation were mediated primarily by the ERK1/2 MAP kinase pathway. These data indicate that there are functional interactions among mast cells, PAR-2 activation, and increased expression of COX-2 in bladder inflammation.
Opioid growth factor-opioid growth factor receptor axis is a physiological determinant of cell proliferation in diverse human cancers
Authors: Zagon Ian S. , Donahue Renee N. , McLaughlin Patricia J.
Published: August 2009

The opioid growth factor (OGF) regulates cell proliferation of human cancer cells through the cyclin-dependent kinase inhibitory pathway, with mediation of this action by the OGF receptor (OGFr). The ubiquity of the OGF-OGFr axis in human cancer is unknown. We used 31 human cancer cell lines, representative of more than 90% of neoplasias occurring in humans, and found that OGF and OGFr were detected in the cytoplasm and nucleus by immunohistochemistry. The addition of OGF to cultures depressed cell number up to 41%, whereas naltrexone (NTX) increased cell proliferation by up to 44%, a total of 85% in the modulating capacity for the OGF-OGFr axis. Neutralization of OGF by specific antibodies led to a marked increase in cell number. Knockdown of OGFr by OGFr-siRNA resulted in a significant increase in the number of cells, even in the face of the addition of exogenous OGF. The cultures to which NTX was added and subjected to OGFr-siRNA were similar to those with OGF-siRNA alone. The OGF-OGFr axis, a physiological determinant of cell-proliferative activity, is a ubiquitous feature of human cancer cells. The identification of this native biological system in neoplasia may be important in understanding the pathophysiology of neoplasia, and in designing treatment modalities that utilize the body's own chemistry.
Regulation of rat intestinal Na-dependent phosphate transporters by dietary phosphate
Authors: Giral Hector , Caldas Yupanqui , Sutherland Eileen , Wilson Paul , Breusegem Sophia , Barry Nicholas , Blaine Judith , Jiang Tao , Wang Xiaoxin X. , Levi Moshe
Published: August 2009

Hyperphosphatemia associated with chronic kidney disease is one of the factors that can promote vascular calcification, and intestinal Pi absorption is one of the pharmacological targets that prevents it. The type II Na-Pi cotransporter NaPi-2b is the major transporter that mediates Pi reabsorption in the intestine. The potential role and regulation of other Na-Pi transporters remain unknown. We have identified expression of the type III Na-Pi cotransporter PiT-1 in the apical membrane of enterocytes. Na-Pi transport activity and NaPi-2b and PiT-1 proteins are mostly expressed in the duodenum and jejunum of rat small intestine; their expression is negligible in the ileum. In response to a chronic low-Pi diet, there is an adaptive response restricted to the jejunum, with increased brush border membrane (BBM) Na-Pi transport activity and NaPi-2b, but not PiT-1, protein and mRNA abundance. However, in rats acutely switched from a low- to a high-Pi diet, there is an increase in BBM Na-Pi transport activity in the duodenum that is associated with an increase in BBM NaPi-2b protein abundance. Acute adaptive upregulation is restricted to the duodenum and induces an increase in serum Pi that produces a transient postprandial hyperphosphatemia. Our study, therefore, indicates that Na-Pi transport activity and NaPi-2b protein expression are differentially regulated in the duodenum vs. the jejunum and that postprandial upregulation of NaPi-2b could be a potential target for treatment of hyperphosphatemia.
Early exposure to germs modifies kidney damage and inflammation after experimental ischemia-reperfusion injury
Authors: Jang Hye Ryoun , Gandolfo Maria Teresa , Ko Gang Jee , Satpute Shailesh , Racusen Lorraine , Rabb Hamid
Published: August 2009

Kidney ischemia-reperfusion injury (IRI) is, in part, mediated by immune and inflammatory factors. Since microbial stimuli are known to alter immune and inflammatory responses, we hypothesized that differences in perinatal microbial status would modify renal injury following IRI. We performed bilateral renal IRI on 6-wk-old germ-free and control mice and studied the effects on kidney lymphocyte trafficking, cytokines, function, and structure. Compared with control mice, normal kidneys of germ-free mice exhibited more NKT cells and lower IL-4 levels. Postischemia, more CD8 T cells trafficked into postischemic kidneys of germ-free mice compared with control mice. Renal structural injury and functional decline following IRI were more severe in germ-free mice compared with control mice. When germ-free mice were conventionalized with the addition of bacteria to their diet, the extent of renal injury after IRI became equivalent to age-matched control mice, with similar numbers and phenotypes of T cells and NKT cells, as well as cytokine expression in both normal kidneys and postischemic kidneys of conventionalized germ-free mice and age-matched control mice. Thus microbial stimuli influence the phenotype of renal lymphocytes and the expression of cytokines of normal kidneys and also modulate the outcome of IRI.
Dietary quercetin supplementation is not ergogenic in untrained men
Authors: Cureton Kirk J. , Tomporowski Phillip D. , Singhal Arpit , Pasley Jeffrey D. , Bigelman Kevin A. , Lambourne Kathleen , Trilk Jennifer L. , McCully Kevin K. , Arnaud Maurice J. , Zhao Qun
Published: August 2009

Quercetin supplementation increases muscle oxidative capacity and endurance in mice, but its ergogenic effect in humans has not been established. Our study investigates the effects of short-duration chronic quercetin supplementation on muscle oxidative capacity; metabolic, perceptual, and neuromuscular determinants of performance in prolonged exercise; and cycling performance in untrained men. Using a double-blind, pretest-posttest control group design, 30 recreationally active, but not endurance-trained, young men were randomly assigned to quercetin and placebo groups. A noninvasive measure of muscle oxidative capacity (phosphocreatine recovery rate using magnetic resonance spectroscopy), peak oxygen uptake (V̇o2peak), metabolic and perceptual responses to submaximal exercise, work performed on a 10-min maximal-effort cycling test following the submaximal cycling, and voluntary and electrically evoked strength loss following cycling were measured before and after 7–16 days of supplementation with 1 g/day of quercetin in a sports hydration beverage or a placebo beverage. Pretreatment-to-posttreatment changes in phosphocreatine recovery time constant, V̇o2peak, substrate utilization, and perception of effort during submaximal exercise, total work done during the 10-min maximal effort cycling trial, and voluntary and electrically evoked strength loss were not significantly different ( P > 0.05) in the quercetin and placebo groups. Short duration, chronic dietary quercetin supplementation in untrained men does not improve muscle oxidative capacity; metabolic, neuromuscular and perceptual determinants of performance in prolonged exercise; or cycling performance. The null findings indicate that metabolic and physical performance consequences of quercetin supplementation observed in mice should not be generalized to humans.
Anatomical and Electrophysiological Comparison of CA1 Pyramidal Neurons of the Rat and Mouse
Authors: Routh Brandy N. , Johnston Daniel , Harris Kristen , Chitwood Raymond A.
Published: August 2009

The study of learning and memory at the single-neuron level has relied on the use of many animal models, most notably rodents. Although many physiological and anatomical studies have been carried out in rats, the advent of genetically engineered mice has necessitated the comparison of new results in mice to established results from rats. Here we compare fundamental physiological and morphological properties and create three-dimensional compartmental models of identified hippocampal CA1 pyramidal neurons of one strain of rat, Sprague–Dawley, and two strains of mice, C57BL/6 and 129/SvEv. We report several differences in neuronal physiology and anatomy among the three animal groups, the most notable being that neurons of the 129/SvEv mice, but not the C57BL/6 mice, have higher input resistance, lower dendritic surface area, and smaller spines than those of rats. A surprising species-specific difference in membrane resonance indicates that both mouse strains have lower levels of the hyperpolarization-activated nonspecific cation current Ih. Simulations suggest that differences in Ih kinetics rather than maximal conductance account for the lower resonance. Our findings indicate that comparisons of data obtained across strains or species will need to account for these and potentially other physiological and anatomical differences.