bluuebunny/crossref_metadata_2025_split huggingface dataset:
Environmental Control of Early Succession on a Large Landslide in a Tropical Dry Ecosystem (Casita Volcano, Nicaragua)
Authors: Velázquez Eduardo , Gómez‐Sal Antonio 
Published: May 2007

ABSTRACTWe described the plant communities on a large landslide in a human‐dominated area of tropical dry forest landscape (Casita Volcano, Nicaragua) and in the adjacent forest, 3 yr after landslide occurrence. At both sites, we determined the relationships between spatial changes in environmental factors and the spatial distribution of species and plant traits. Subsequently, we tested the hypothesis that the compositional similarity between the landslide and the forest increased with a decrease in the distance from the forest edge and the width of the landslide. In the forest, the spatial distribution of species and plant traits was determined mainly by an elevational gradient that was associated with the amount of bare soil, whereas, on the landslide, there was no such gradient but species distributions were influenced mostly by the presence of residual agricultural and forest soils and human disturbance. We did not find an increase in compositional similarity between the landslide and the forest at the edge or in the narrow zones of the landslide. Compared to other landslides, the recovery process was strongly influenced by the extreme abiotic heterogeneity, climate seasonality, and human use in the area. The study of succession in tropical dry landslides located in densely populated zones should focus on understanding the response of regional ecosystems to a complex disturbance regime in which human‐induced disturbances play a major role.
Prospective Randomized Trial of Empiric Therapy with Trimethoprim-Sulfamethoxazole or Doxycycline for Outpatient Skin and Soft Tissue Infections in an Area of High Prevalence of Methicillin-Resistant
Staphylococcus aureus
Authors: Cenizal Mary Jo , Skiest Daniel , Luber Samuel , Bedimo Roger , Davis Pat , Fox Patrick , Delaney Kathleen , Hardy R. Doug 
Published: May 2007

ABSTRACT

To evaluate empirical therapy with trimethoprim-sulfamethoxazole or doxycycline for outpatient skin and soft tissue infections in an area of high prevalence of methicillin-resistant
Staphylococcus aureus
, a randomized, prospective, open-label investigation was performed. The overall clinical failure rate was 9%, with all failures occurring in the trimethoprim-sulfamethoxazole group. However, there was no significant difference between the clinical failure rate of empirical trimethoprim-sulfamethoxazole therapy and that of doxycycline therapy.
Calcineurin Inhibition or Mutation Enhances Cell Wall Inhibitors against
Aspergillus fumigatus
Authors: Steinbach William J. , Cramer Robert A. , Perfect B. Zachary , Henn Christina , Nielsen Kirsten , Heitman Joseph , Perfect John R. 
Published: May 2007

ABSTRACT

Calcineurin mutation or inhibition enhanced the antifungal morphological effect of cell wall inhibitors caspofungin or nikkomycin Z against
Aspergillus fumigatus
. Quantification of 1,3-β-
d
-glucan revealed decreased amounts in the calcineurin A (Δ
cnaA
) mutant. Calcineurin can be an excellent adjunct therapeutic target in combination with other cell wall inhibitors against
A. fumigatus
.
Active and Passive Immunizations with the Streptococcal Esterase Sse Protect Mice against Subcutaneous Infection with Group A Streptococci
Authors: Liu Mengyao , Zhu Hui , Zhang Jinlian , Lei Benfang 
Published: May 2007

ABSTRACTThe human pathogen group AStreptococcus(GAS) produces many secreted proteins that play important roles in GAS pathogenesis, including hydrolases that degrade proteins and nucleic acids. This study targets another kind of hydrolase, carboxylic esterase, with the objectives of identifying GAS esterase and determining whether it is a protective antigen. The putative esterase gene SPy1718 was cloned, and the recombinant protein (Sse) was prepared. Sse was detected in GAS culture supernatant, and patients with streptococcal pharyngitis seroconverted to Sse, indicating that Sse was produced in vivo and in vitro. Sse hydrolyzesp-nitrophenyl butyrate, and the residue178Ser is critical for this esterase activity. There are two Sse variant complexes according to the available genome databases, consistent with the previous finding of two antigenic Sse variants. Complex I includes serotypes M1, M2, M3, M5, M6, M12, and M18, whereas M4, M28, and M49 belong to complex II. Sse variants share >98% identity in amino acid sequence within each complex but have about 37% variation between the two groups. Active immunization with M1 Sse significantly protects mice against lethal subcutaneous infection with virulent M1 and M3 strains and inhibits GAS invasion of mouse skin tissue. Passive immunization with anti-Sse antiserum also significantly protects mice against subcutaneous GAS infection, indicating that the protection is mediated by Sse-specific antibodies. The results suggest that Sse plays an important role in tissue invasion and is an antigen protective in subcutaneous infection against GAS strains of more than one serotype.
Mucosal Immunization with a Novel Nanoemulsion-Based Recombinant Anthrax Protective Antigen Vaccine Protects againstBacillus anthracisSpore Challenge
Authors: Bielinska Anna U. , Janczak Katarzyna W. , Landers Jeffrey J. , Makidon Paul , Sower Laurie E. , Peterson Johnny W. , Baker James R. 
Published: May 2007

ABSTRACTThe currently available commercial human anthrax vaccine requires multiple injections for efficacy and has side effects due to its alum adjuvant. These factors limit its utility when immunizing exposed populations in emergent situations. We evaluated a novel mucosal adjuvant that consists of a nontoxic, water-in-oil nanoemulsion (NE). This material does not contain a proinflammatory component but penetrates mucosal surfaces to load antigens into dendritic cells. Mice and guinea pigs were intranasally immunized with recombinantBacillus anthracisprotective antigen (rPA) mixed in NE as an adjuvant. rPA-NE immunization was effective in inducing both serum anti-PA immunoglobulin G (IgG) and bronchial anti-PA IgA and IgG antibodies after either one or two mucosal administrations. Serum anti-PA IgG2a and IgG2b antibodies and PA-specific cytokine induction after immunization indicate a Th1-polarized immune response. rPA-NE immunization also produced high titers of lethal-toxin-neutralizing serum antibodies in both mice and guinea pigs. Guinea pigs nasally immunized with rPA-NE vaccine were protected against an intradermal challenge with ∼1,000 times the 50% lethal dose (∼1,000× LD50) ofB. anthracisAmes strain spores (1.38 × 103spores), which killed control animals within 96 h. Nasal immunization also resulted in 70% and 40% survival rates against intranasal challenge with 10× LD50and 100× LD50(1.2 × 106and 1.2 × 107) Ames strain spores. Our results indicate that NE can effectively adjuvant rPA for intranasal immunization. This potentially could lead to a needle-free anthrax vaccine requiring fewer doses and having fewer side effects than the currently available human vaccine.
Mechanisms of
Chlamydia trachomatis
Entry into Nonphagocytic Cells
Authors: Hybiske Kevin , Stephens Richard S. 
Published: May 2007

ABSTRACT

The mechanisms of entry for the obligate intracellular bacterium
C. trachomatis
were examined by functional disruption of proteins essential for various modes of entry. RNA interference was used to disrupt proteins with established roles in clathrin-mediated endocytosis (clathrin heavy chain, dynamin-2, heat shock 70-kDa protein 8, Arp2, cortactin, and calmodulin), caveola-mediated endocytosis (caveolin-1, dynamin-2, Arp2, NSF, and annexin II), phagocytosis (RhoA, dynamin-2, Rac1, and Arp2), and macropinocytosis (Pak1, Rac1, and Arp2). Comparative quantitative PCR analysis was performed on small interfering RNA-transfected HeLa cells to accurately determine the extent of
C. trachomatis
entry after these treatments. Key structural and regulatory factors associated with clathrin-mediated endocytosis were found to be involved in
Chlamydia
entry, whereas those for caveola-mediated endocytosis, phagocytosis, and macropinocytosis were not. Thus, clathrin and its coordinate accessory factors were required for entry of
C. trachomatis
, although additional, uncharacterized mechanisms are also utilized.
Protective Role of
Bacillus anthracis
Exosporium in Macrophage-Mediated Killing by Nitric Oxide
Authors: Weaver John , Kang Tae Jin , Raines Kimberly W. , Cao Guan-Liang , Hibbs Stephen , Tsai Pei , Baillie Les , Rosen Gerald M. , Cross Alan S. 
Published: May 2007

ABSTRACT

The ability of the endospore-forming, gram-positive bacterium
Bacillus anthracis
to survive in activated macrophages is key to its germination and survival. In a previous publication, we discovered that exposure of primary murine macrophages to
B. anthracis
endospores upregulated NOS 2 concomitant with an ·NO-dependent bactericidal response. Since NOS 2 also generates O
2
·
−
, experiments were designed to determine whether NOS 2 formed peroxynitrite (ONOO
−
) from the reaction of ·NO with O
2
·
−
and if so, was ONOO
−
microbicidal toward
B. anthracis
. Our findings suggest that ONOO
−
was formed upon macrophage infection by
B. anthracis
endospores; however, ONOO
−
does not appear to exhibit microbicidal activity toward this bacterium. In contrast, the exosporium of
B. anthracis
, which exhibits arginase activity, protected
B. anthracis
from macrophage-mediated killing by decreasing ·NO levels in the macrophage. Thus, the ability of
B. anthracis
to subvert ·NO production has important implications in the control of
B. anthracis
-induced infection.
ThePseudomonas aeruginosaSecreted Protein PA2934 Decreases Apical Membrane Expression of the Cystic Fibrosis Transmembrane Conductance Regulator
Authors: MacEachran Daniel P. , Ye Siying , Bomberger Jennifer M. , Hogan Deborah A. , Swiatecka-Urban Agnieszka , Stanton Bruce A. , O'Toole George A. 
Published: May 2007

ABSTRACTWe previously reported thatPseudomonas aeruginosaPA14 secretes a protein that can reduce the apical membrane expression of thecysticfibrosistransmembrane conductanceregulator (CFTR) protein. Here we report that we have used a proteomic approach to identify this secreted protein as PA2394, and we have named the genecif, forCFTRinhibitoryfactor. We demonstrate that Cif is a secreted protein and is found associated with outer membrane-derived vesicles. Expression of Cif inEscherichia coliand purification of the C-terminal six-His-tagged Cif protein showed that Cif is necessary and sufficient to mediate the reduction in apical membrane expression of CFTR and a concomitant reduction in CFTR-mediated Cl−ion secretion. Cif demonstrates epoxide hydrolase activity in vitro and requires a highly conserved histidine residue identified in α/β hydrolase family enzymes to catalyze this reaction. Mutating this histidine residue also abolishes the ability of Cif to reduce apical membrane CFTR expression. Finally, we demonstrate that thecifgene is expressed in the cystic fibrosis (CF) lung and that nonmucoid isolates ofP. aeruginosashow greater expression of the gene than do mucoid isolates. We propose a model in which the Cif-mediated decrease in apical membrane expression of CFTR by environmental isolates ofP. aeruginosafacilitates the colonization of the CF lung by this microbe.
Enhanced Immunity toPlasmodium falciparumCircumsporozoite Protein (PfCSP) by UsingSalmonella entericaSerovar Typhi Expressing PfCSP and a PfCSP-Encoding DNA Vaccine in a Heterologous Prime-Boost Strategy
Authors: Chinchilla Magaly , Pasetti Marcela F. , Medina-Moreno Sandra , Wang Jin Yuan , Gomez-Duarte Oscar G. , Stout Rick , Levine Myron M. , Galen James E. 
Published: May 2007

ABSTRACTTwoSalmonella entericaserovar Typhi strains that express and export a truncated version ofPlasmodium falciparumcircumsporozoite surface protein (tCSP) fused toSalmonellaserovar TyphicytolysinA(ClyA) were constructed as a first step in the development of a preerythrocytic malaria vaccine. Synthetic codon-optimized genes (t-csp1and t-csp2), containing immunodominant B- and T-cell epitopes present in nativeP. falciparumcircumsporozoite surface protein (PfCSP), were fused in frame to the carboxyl terminus of the ClyA gene (clyA::t-csp) in genetically stabilized expression plasmids. Expression and export of ClyA-tCSP1 and ClyA-tCSP2 bySalmonellaserovar Typhi vaccine strain CVD 908-htrAwere demonstrated by immunoblotting of whole-cell lysates and culture supernatants. The immunogenicity of these constructs was evaluated using a “heterologous prime-boost” approach consisting of mucosal priming withSalmonellaserovar Typhi expressing ClyA-tCSP1 and ClyA-tCSP2, followed by parenteral boosting with PfCSP DNA vaccines pVR2510 and pVR2571. Mice primed intranasally on days 0 and 28 with CVD 908-htrA(pSEC10tcsp2) and boosted intradermally on day 56 with PfCSP DNA vaccine pVR2571 induced high titers of serum NANP immunoglobulin G (IgG) (predominantly IgG2a); no serological responses to DNA vaccination were observed in the absence ofSalmonellaserovar Typhi-PfCSP priming. Mice primed withSalmonellaserovar Typhi expressing tCSP2 and boosted with PfCSP DNA also developed high frequencies of gamma interferon-secreting cells, which surpassed those produced by PfCSP DNA in the absence of priming. A prime-boost regimen consisting of mucosal delivery of PfCSP exported from aSalmonella-based live-vector vaccine followed by a parenteral PfCSP DNA boosting is a promising strategy for the development of a live-vector-based malaria vaccine.
PorA Variable Antigenic Regions VR1, VR2, and VR3 of
Neisseria meningitidis
Serogroups B and C Isolated in Brazil from 1999 to 2004
Authors: de Filippis Ivano , de Andrade Claudia Ferreira , Silva Luciete , Prevots D. Rebecca , Vicente Ana Carolina P. 
Published: May 2007

ABSTRACT

The high genetic diversity found among the PorA regions VR1 and VR2 of 101
Neisseria meningitidis
isolates from patients with meningococcal disease and healthy carriers in Brazil contrasts with the stability found in the PorA VR3 of these isolates. The presence of VR3 epitope variant 35 or 36 on the surfaces of 87% of the strains analyzed suggests that these antigens should be considered for inclusion in new formulations of vaccines against serogroup B meningococci in Brazil.
Influence ofMycobacterium aviumsubsp.paratuberculosison Colitis Development and Specific Immune Responses during Disease
Authors: Singh Udai P. , Singh Shailesh , Singh Rajesh , Karls Russell K. , Quinn Frederick D. , Potter Morris E. , Lillard James W. 
Published: May 2007

ABSTRACTThe granulomatous and intramural inflammation observed in cases of inflammatory bowel diseases (IBD) and veterinary Johne's disease suggests thatMycobacterium aviumsubsp.paratuberculosisis a causative agent. However, an incomplete understanding of the immunological steps responsible for the pathologies of IBD makes this conclusion uncertain. Sera from interleukin-10-deficient (IL-10−/−) mice with spontaneous colitis displayed significantly higherM. aviumsubsp.paratuberculosis-specific immunoglobulin G2a antibody responses than did sera from similar mice without disease. Pathogen-free IL-10−/−mice received control vehicle or the vehicle containing heat-killed or liveM. aviumsubsp.paratuberculosis. Mucosal CD4+T cells from the mice that developed colitis proliferated and secreted higher levels of gamma interferon and tumor necrosis factor alpha after ex vivo stimulation with a Vβ11+T-cell receptor-restricted peptide from the MPT59 antigen (Ag85B) than those secreted from cells from mice before the onset of colitis. The data from this study provide important information regarding the mechanisms of colitis in IL-10−/−mice, which are driven in part by Ag85B-specific T cells. The data suggest a plausible mechanism of Ag-specific T-cell responses in colitis driven by potent Ags conserved inMycobacteriumspecies.
Ligand Migration in the Reaction of Titanium Complexes with AlMe3
Authors: Kobyłka Michał J. , Jerzykiewicz Lucjan B. , Patton Jasson T. , Przybylak Szymon , Utko Józef , Sobota Piotr 
Published: May 2007

Five different titanium compounds cis-[Ti(η2-hbo)2(OEt)2]·0.5toluene (1), cis-[TiCl2(η2-thp)2] (2), [TiCl2(edbp)2] (3), [Ti2(μ-OMe)2(edbp)2(Me)2] (6), [Ti2(μ-OMe)2(edbp)2(OMe)2] (7) (Hhbo = 2-(2-hydroxyfenyl)benzoxazole, Hthp = tetrahydropyran-2-methanol, H2edbp = 2,2'-ethylidenebis(4,6-di-tert-butylphenol)), have been prepared and tested in combination with MAO as catalysts for propene polymerization and ethene and oct-1-ene copolymerization with the aim of gaining insight into the structure of the active species. Investigation of the 1/AlMe3 or 2/AlMe3 systems resulted in isolation of [Al(η2-hbo)2(Me)] (4) and [Al2(μ2-η2-thp)2(Me)4] (5) in high yields. This indicates that the trimethylaluminum contained in MAO abstracts ligands from 1 or 2, affecting thus the catalytic performance of the 1,2/MAO catalysts. In contrast, compound 3 reacted with MAO affording methylated product 6. Accordingly, the 3/MAO catalyst differed from the above ones, furnishing at 70 °C e.g., narrow molecular weight polypropylene (Mn = 454 000; Mw/Mn = 2.49; Tm = 158.2 °C).
Impact of low-intensity isocapnic hyperpnoea on blood lactate disappearance after exhaustive arm exercise
Authors: Perret Claudio , Mueller Gabi 
Published: May 2007

Objective:To investigate the impact of low-intensity isocapnic hyperpnoea (IH) on blood lactate disappearance after exhaustive arm exercise in comparison with passive and active recovery using the previously loaded muscle group.Design:Randomised, crossover trial.Setting:Institute for Sports Medicine.Participants:18 healthy non-smoking and physically active male subjects.Interventions:Subjects performed three arm cranking tests to volitional exhaustion on 3 different days at least 48 h apart. Arm exercise was randomly followed by 30 min of passive recovery (PR), active arm cranking (AC) at 30% of peak power output or ventilatory recovery (VR) by means of IH at 30% of 12 s maximal voluntary ventilation. Blood lactate concentrations were measured every 2 min during recovery.Main outcome measurements:Blood lactate disappearance during the three different recovery strategies.Results:No significant differences in blood lactate concentrations were found between interventions PR, AC and VR during the whole measurement period. Mean (SD) peak lactate concentrations were 11.09 (1.98) mmol/l for PR, 11.13 (1.44) mmol/l for AC and 11.25 (1.93) mmol/l for VR. At the end of the recovery period measured lactate concentrations were 4.35 (1.56) mmol/l for PR, 3.77 (1.60) mmol/l for AC and 4.09 (1.35) mmol/l for VR. Moreover, all other variables measured were not significantly different, with the exception of higher average recovery heart rates during AC (116 (9) bpm) and VR (111 (17) bpm) compared with PR (93 (11) bpm).Conclusion:Low-intensity IH seems not to enhance blood lactate disappearance after exhaustive arm exercise compared with passive or active recovery using the previously loaded muscle group. The magnitude of the involved muscle mass appears critical to effective active recovery.
NOVEL ONE-DIMENSIONAL STATES IN A BENT QUANTUM HALL JUNCTION
Authors: GRAYSON M. , STEINKE L. , HUBER M. , SCHUH D. , BICHLER M. , ABSTREITER G. , HOEPPEL L. , SMET J. , v. KLITZING K. , MAUDE D. K. 
Published: May 2007

Using a recently developed crystal growth technique (see Fig. 1), we have succeeded in creating a two-dimensional (2D) electron system that is bent at an atomically sharp angle of 90°1. Naming the two 2D systems after their substrate (S) and precleave (P) facets, we can measure their densities ns and np. In the presence of a tilted magnetic field, this system realizes an abrupt junction between two quantum Hall effect (QH) systems with arbitrary filling factors2νs = nsh/eB cos (θ) and νp = nph/eB sin (θ). When the two filling factors are equal νs = νp, the corner junction represents a multimode wire with the maximum number of forward & reverse moving modes equalling the filling factor ν plus two spin degenerate modes from corner-accumulation wire. The conductance of this bent QH system dI/dV(V) or G(T) can be characterized with four-point measurements. As long as the excitation energy (V or T, respectively) is smaller than the QH gap energy, there is no scattering of electrons away from the wire system to the 2D bulk and the transport is truly one-dimensional. The devices studied here are from 0.4 - 4 mm long with ohmic contacts alloyed on both facets away from the junction. The resulting 1D wire at the corner junction has exhibited metallic, insulating, and critical phases depending on filling factor, with all 1D conductances of order 0.02e2/h or below. The insulating 1D behavior occurs for ν = 1 and ν = 2, and is manifest in a vanishing 1D conductance at low temperatures and low dc voltage biases. Metallic 1D behavior occurs for ν = 1/3 where the conductance rises with decreasing temperature and the dc bias shows a large zero-bias peak in the differential conductivity. The so-called critical behavior has only weak temperature dependence and a weak zero-bias dip in the dc bias voltage dependence. The conductance G at ν = 3 and ν = 4 goes inversely with the wire length L indicating that scattering is distributed equally along the wire length. These observations can be partly explained with Hartree calculations of the bent quantum Hall junction. Low magnetic fields (ν = 3 and 4) are expected to manifest a multimode wire, which provides a basis for understanding the critical phase. Higher magnetic fields (ν = 1 and 2) are expected to open up a gap in the 1D energy spectrum at the corner, resulting in the experimentally observed insulating phase. Alternatively, disorder may also explain the 1D insulating behavior via scaling theory of localization. The highest magnetic fields for the fractional state ν = 1/3 show the remarkable metallic phase which might be explained in terms of an antiwire between counterpropagating ν = 1/3 Luttinger liquid edges which are randomly coupled by electron back-scattering events3.
Phase I Clinical and Pharmacodynamic Evaluation of Oral CI-1033 in Patients with Refractory Cancer
Authors: Zinner Ralph G. , Nemunaitis John , Eiseman Irene , Shin Hyung Ju C. , Olson Stephen C. , Christensen James , Huang Xin , Lenehan Peter F. , Donato Nicholas J. , Shin Dong M. 
Published: May 2007

Abstract
Purpose: To determine the tolerability and pharmacokinetics of CI-1033 given daily for 7 days of a 21-day cycle. Tumor response and changes in erbB receptor tyrosine kinase activity in tumor and skin tissue were examined, and modulation of potential biomarkers in plasma was explored.
Design: This was a dose-finding phase I study in patients with advanced solid malignancies. Patients were evaluated for safety, pharmacokinetics, and tumor response. Pharmacodynamic markers, such as Ki67, p27, and erbB receptor status, were assessed in tumor and skin tissue using immunohistochemical and immunoprecipitation methodologies. Plasma biomarkers HER2, vascular endothelial growth factor, interleukin-8, and matrix metalloproteinase-9 were evaluated using immunologic techniques.
Results: Fifty-three patients were enrolled in the study. Dose-limiting toxicity (emesis, persistent rash, and mouth ulcer) was observed at 750 mg. The maximum tolerated dose was 650 mg. There were no confirmed objective responses. CI-1033 treatment showed down-regulation of epidermal growth factor receptor, HER2, and Ki67 in a variety of tumor tissues and up regulation of p27 in skin tissue. Plasma HER2 was reduced following CI-1033 administration, but no consistent change in vascular endothelial growth factor, interleukin-8, or matrix metalloproteinase-9 was noted. CI-1033 plasma concentrations were proportional to dose.
Conclusion: The safety and pharmacokinetic profile of CI-1033 was favorable for multidose oral administration. Evidence of modulation of erbB receptor activity in tumor and skin tissue was accompanied by changes in markers of proliferation and cell cycle inhibition. Additional clinical trials are warranted in defining the role of CI-1033 in the treatment of cancer and further assessing the utility of antitumor markers.