bluuebunny/crossref_metadata_2025 huggingface dataset:
Methanethiol accumulation exacerbates release of N2O during denitrification in estuarine sediments and bacterial cultures
Authors: Magalhães C. , Kiene R. P. , Buchan A. , Machado A. , Wiebe W. J. , Bordalo A. A.
Published: December 2010

Microbes play critical roles in the biogeochemical cycling of nitrogen and sulfur in aquatic environments. Here we investigated the interaction between the naturally occurring organic sulfur compound methanethiol (MeSH) and the final step of the denitrification pathway, the reduction of nitrous oxide (N2O) to dinitrogen (N2) gas, in sediment slurries from the temperate Douro and Ave estuaries (NW Portugal) and in pure cultures of the marine bacterium Ruegeria pomeroyi. Sediment slurries and cell suspensions were amended with a range of concentrations of either MeSH (0–120 µM) or methionine (0–5 mM), a known precursor of MeSH. MeSH or methionine additions caused N2O to accumulate and this accumulation was linearly related to MeSH concentrations in both coastal sediments (R2 = 0.7–0.9, P < 0.05) and R. pomeroyi cell suspensions (R2 = 0.9, P < 0.01). Our results suggest that MeSH inhibits the final step of denitrification resulting in N2O accumulation.
Almahata Sitta (=asteroid 2008 TC3) and the search for the ureilite parent body
Authors: JENNISKENS Peter , VAUBAILLON Jérémie , BINZEL Richard P. , DeMEO Francesca E. , NESVORNÝ David , BOTTKE William F. , FITZSIMMONS Alan , HIROI Takahiro , MARCHIS Franck , BISHOP Janice L. , VERNAZZA Pierre , ZOLENSKY Michael E. , HERRIN Jason S. , WELTEN Kees C. , MEIER Matthias M. M. , SHADDAD Muawia H.
Published: December 2010

Abstract– This article explores what the recovery of 2008 TC3 in the form of the Almahata Sitta meteorites may tell us about the source region of ureilites in the main asteroid belt. An investigation is made into what is known about asteroids with roughly the same spectroscopic signature as 2008 TC3. A population of low‐inclination near‐Earth asteroids is identified with spectra similar to 2008 TC3. Five asteroid families in the Main Belt, as well as a population of ungrouped asteroids scattered in the inner and central belts, are identified as possible source regions for this near‐Earth population and 2008 TC3. Three of the families are ruled out on dynamical and spectroscopic grounds. New near‐infrared spectra of 142 Polana and 1726 Hoffmeister, lead objects in the two other families, also show a poor match to Almahata Sitta. Thus, there are no Main Belt spectral analogs to Almahata Sitta currently known. Space weathering effects on ureilitic materials have not been investigated, so that it is unclear how the spectrum of the Main Belt progenitor may look different from the spectra of 2008 TC3 and the Almahata Sitta meteorites. Dynamical arguments are discussed, as well as ureilite petrogenesis and parent body evolution models, but these considerations do not conclusively point to a source region either, other than that 2008 TC3 probably originated in the inner asteroid belt.
A Feedback Linearization Approach for Panel Flutter Suppression With Piezoelectric Actuation
Authors: Onawola Oluseyi O. , Sinha S. C.
Published: December 2010

Panel flutter suppression by exact state transformations and feedback control using piezoelectric actuation is presented. A nonlinear control system is designed for a simply supported rectangular panel with bonded piezoelectric layers based on the von Kármán large-deflection plate theory. The governing nonlinear partial differential equation for the panel is reduced to a set of ordinary differential equations using a two mode approximation. Distributed piezoelectric actuators and sensors connected to processing networks are used as modal actuators and sensors to actively control panel vibrations. The control inputs are given by the electric fields required to drive the actuators based on piezoelectric actuation. Nonlinear feedback control laws are formulated through a transformation of the discretized nonlinear system into an equivalent controllable linear system. The simulated results show that the resulting closed-loop system based on feedback linearized controllers effectively suppress panel flutter limit-cycle motions.
Measurement of Wavy Surface Oscillations on Liquid Metal Lithium Jet for IFMIF Target
Authors: Sugiura Hirokazu , Kanemura Takuji , Yoshihashi-Suzuki Sachiko , Kondo Hiroo , Yoshikawa Tomohide , Yamaoka Nobuo , Ida Mizuho , Nakamura Hiroo , Matsushita Izuru , Horiike Hiroshi
Published: December 2010

The International Fusion Materials Irradiation Facility (IFMIF) has been conceived as a high-flux 14 MeV neutron source for testing candidate fusion reactor materials. In the current design, neutrons are generated by irradiating a target with a deuteron beam and high-speed free-surface flow of liquid metal lithium (Li) is adopted as the target. To reveal the stability of the Li flow, we have examined characteristics of surface waves at a location 175 nm downstream from a nozzle exit, which corresponds to the center of the beam irradiated region. In this study, the characteristics of surface waves just downstream of the nozzle exit were measured experimentally, since the initial growth of surface waves exerts a definite influence on the surface behavior of the Li flow in the downstream region. Experiments were carried out with a focus on surface oscillations of the Li flow using the lithium circulation loop at Osaka University. These oscillations are measured using an electro-contact probe apparatus, which can detect electrically a contact between the probe tip and the Li surface and provide local height data of surface waves. The apparatus was installed at a location 15 mm downstream from the nozzle exit and scanned the Li surface by moving along the liquid-depth direction. The experiments were performed for the velocity range of 3-15 m/s under argon gas atmosphere at a pressure of 0.13 MPa. The contact signal recorded in the experiment was used to analyze the characteristics of surface waves, and then the root-mean-square wave amplitude and the frequency of surface waves were calculated. It was found that the root-mean-square wave amplitudes of surface waves increased with a rise in the flow velocity, and reached approximately 0.18 mm at 14-15 m/s. And also, obtained frequencies were analyzed using a linear stability theory, and the variation of frequencies was examined with the mean flow velocity.
Entropically Stabilized Local Dipole Formation in Lead Chalcogenides
Authors: Božin Emil S. , Malliakas Christos D. , Souvatzis Petros , Proffen Thomas , Spaldin Nicola A. , Kanatzidis Mercouri G. , Billinge Simon J. L.
Published: December 2010

A Hot Dipole

In a ferroelectric material, there is an alignment of local electric dipole moments that produces a net overall electric polarization. This state is accompanied by a decrease in symmetry, which can be restored by heating above a critical temperature. In contrast, through a combination of theory and experiments,

Božin
et al.

(p.
1660
) now show that with increasing temperature, rock-salt–structured lead telluride and lead sulfide go through a phase transition from a high symmetry phase to a low symmetry phase with an associated dipole moment. Paradoxically, the dipoles are stabilized in the disordered state at high temperature, even though the undistorted structure has lower internal energy.
Experimental Spin Ratchet
Authors: Costache Marius V. , Valenzuela Sergio O.
Published: December 2010

Spin Control

Controlling and manipulating the spin of an electron is a central requirement for applications in spintronics. Some of the challenges researchers are facing include efficient creation of spin currents, minimization of Joule heating, and extending the lifetime of electronic spins, which is especially important for quantum information applications.
Costache and Valenzuela
(p.
1645
) address the first challenge by designing and fabricating an efficient and simple superconducting-based single-electron transistor that can produce spin current with controlled flow. Key to the design is asymmetric tunneling, which leads to a ratchet effect (or diode-like behavior), allowing the separation of up and down spins.

Jonietz
et al.

(p.
1648
) use electric currents five orders of magnitude smaller than those used previously in nanostructures to manipulate magnetization in a bulk material, MnSi, pointing the way toward decreased Joule heating in spintronic devices. This so-called spin-torque effect causes the rotation of the skyrmion lattice of spins, characteristic of MnSi, which is detected by neutron scattering. Finally,

McCamey
et al.

(p.
1652
) extend the short lifetime of an electronic spin of a phosphorous dopant by mapping it onto the much longer lived nuclear spin of the atom. Mapping the nuclear spin back onto the electronic spin allows production of a spin memory with a storage time exceeding 100s, which should prove useful for future practical applications.
Optical Metamaterials—More Bulky and Less Lossy
Authors: Soukoulis Costas M. , Wegener Martin
Published: December 2010

Advanced techniques for bulk fabrication and loss reduction provide good prospects for practical optical metamaterials.
Inventive Constructions Using Biobricks
iGEM 2010 Jamboree
Massachusetts Institute of Technology, Cambridge, MA. 6–8 November 2010. http://2010.igem.org/
Authors: Vinson Valda
Published: December 2010

Some 118 teams from around the world came together for the iGEM 2010 competition in synthetic biology.
Stepping Away From the Trees For a Look at the Forest
Authors:   The News Staff
Published: December 2010

Science
's news staff takes a break from reporting to review some big ideas of the past 10 years and the technologies that made them possible.
A Recipe for the Cosmos
Authors: Cho Adrian
Published: December 2010

In the past decade, cosmologists have deduced a very precise recipe for the content of the universe, as well as instructions for putting it together, transforming cosmology from a largely qualitative endeavor to a precision science with a standard theory.
Enhancement of Immune Responses by an Attenuated
Salmonella enterica
Serovar Typhimurium Strain Secreting an
Escherichia coli
Heat-Labile Enterotoxin B Subunit Protein as an Adjuvant for a Live
Salmonella
Vaccine Candidate
Authors: Hur Jin , Lee John Hwa
Published: December 2010

A plasmid harboring
eltB
, the gene encoding heat-labile enterotoxin (LTB), was constructed by insertion of
eltB
into an Asd
+
β-lactamase signal plasmid (pMMP65). This was introduced into the Δ
lon
Δ
cpxR
Δ
asd Salmonella enterica
serovar Typhimurium strain and designated the LTB adjuvant strain. LTB protein production and secretion from the strain were demonstrated with an immunoblot assay and enzyme-linked immunosorbent assay. The LTB strain was evaluated for enhancement of immunity and protection efficacy induced by a previously constructed live
Salmonella
vaccine candidate. In addition, immunization strategies using the LTB strain were optimized for effective salmonellosis protection. Seventy female BALB/c mice were divided into seven groups (A to G;
n
= 10 mice per group). Mice were primed at 6 weeks of age and boosted at 9 weeks of age. All mice were orally challenged with a virulent wild-type strain at week 3 postbooster. Serum IgG and IgA titers from mice immunized with the LTB strain alone or with a mixture of the LTB strain and the vaccine candidate were significantly increased. The secretory IgA titers from mice immunized with the LTB strain alone or with the mixture were at least 2.2 times greater than those of control mice. In addition, all group E mice (primed with the vaccine-LTB mixture and boosted with the vaccine candidate) were free of clinical signs of salmonellosis and survived a virulent challenge. In contrast, death due to the challenge was 100% in control mice, 80% in group A mice (single immunization with the vaccine candidate), 60% in group B mice (primed and boosted with the vaccine candidate), 40% in group C mice (single immunization with the LTB strain), 30% in group D mice (primed and boosted with the LTB strain), and 30% in group F mice (primed and boosted with the vaccine-LTB mixture). These results suggest that vaccination with the LTB strain, especially when added at the prime stage only, effectively enhances immune responses and protection against salmonellosis.
Effects of Blood Sample Age at Time of Separation on Measured Cytokine Concentrations in Human Plasma
Authors: Jackman Rachael P. , Utter Garth H. , Heitman John W. , Hirschkorn Dale F. , Law Jacqueline P. , Gefter Nelly , Busch Michael P. , Norris Philip J.
Published: December 2010

Measurement of peripheral blood cytokines and other immunomodulatory proteins is a useful and popular tool for assessing human immune responses to a wide range of assaults. A common challenge in this work is obtaining fresh, high-quality samples and limiting the time between blood collection and the separation of plasma or serum from cells. In this study we sought to determine the effect of sample age at the time of processing on the measured levels of 41 soluble immune mediators. Two cohorts were examined: healthy lab donors and trauma patients, who have significant immune perturbation. Whole-blood samples were aliquoted, and plasma was isolated, at days 0, 1, 2, and 3 after collection. Multiplexing techniques were used to measure protein concentrations, and general estimating equations were used to determine if there was a significant change over time. Over the 3-day period examined, only 15 of the 41 proteins showed no significant change in either cohort. Among the remaining proteins both increases and decreases were observed, with changes ranging from 2.4% per day to 325% per day. Proteins with significant changes in one cohort did not always show significant changes in the other group. These results support the need to separate plasma or serum from whole blood as quickly as possible and/or to standardize the length of time to processing within a given study of peripheral blood protein concentrations. When this is not possible, care should be taken to account for differences due to sample age.
Evaluation of DNA Extraction Techniques for Detecting Mycobacterium tuberculosis Complex Organisms in Asian Elephant Trunk Wash Samples
Authors: Kay Meagan K. , Linke Lyndsey , Triantis Joni , Salman M. D. , Larsen R. Scott
Published: December 2010

Rapid and sensitive diagnostic assays for the detection of tuberculous mycobacteria in elephants are lacking. DNA extraction with PCR analysis is useful for tuberculosis screening in many species but has not been validated on elephant trunk wash samples. We estimated the analytical sensitivity and specificity of three DNA extraction methods to detect
Mycobacterium tuberculosis
complex organisms in trunk wash specimens. A ZR soil microbe DNA kit (ZR) and a traditional salt and ethanol precipitation (TSEP) approach were evaluated under three different treatment conditions: heat treatment, phenol treatment, and contamination with
Mycobacterium avium
. A third approach, using a column filtration method, was evaluated for samples contaminated with soil. Trunk wash samples from uninfected elephants were spiked with various concentrations of
M. bovis
cells and subjected to the described treatment conditions prior to DNA extraction. Extracted DNA was amplified using IS
6110
-targeted PCR analysis. The ZR and TSEP methods detected as low as 1 to 5
M. bovis
cells and 10
M. bovis
cells, respectively, per 1.5 ml of trunk wash under all three conditions. Depending on the amount of soil present, the column filtration method detected as low as 5 to 50
M. bovis
cells per 1.5 ml of trunk wash. Analytical specificity was assessed by DNA extraction from species of nontuberculous mycobacteria and amplification using the same PCR technique. Only
M. bovis
DNA was amplified, indicating 100% analytical specificity of this PCR technique. Our results indicate that these DNA extraction techniques offer promise as useful tests for detection of
M. tuberculosis
complex organisms in elephant trunk wash specimens.
Multiple Cases of Cutaneous Mycobacterium massiliense Infection in a “Hot Spa” in Japan
Authors: Nakanaga Kazue , Hoshino Yoshihiko , Era Yuko , Matsumoto Kentaro , Kanazawa Yuji , Tomita Atsuko , Furuta Masanari , Washizu Motohisa , Makino Masahiko , Ishii Norihisa
Published: December 2010

Seven body polishers working in the same “hot spa” presented with multiple red nodules and papules on their hands and forearms. A causative agent was successfully isolated from two of the subjects and from a swab sample collected from the underside of a bed cover in the body-polishing facility. The two cutaneous isolates and the environmental isolate were rapidly growing mycobacteria that formed nonphotochromogenic smooth or smooth/rough colonies on Ogawa egg slants. They were identified as
Mycobacterium massiliense
by multigenotypic analysis using the 16S rRNA,
hsp65
, and
rpoB
genes and the 16S–23S rRNA internal transcribed spacer (ITS) region. However, the use of the 16S rRNA gene sequence and/or DNA-DNA hybridization (DDH Mycobacteria Kit) alone would not distinguish
M. massiliense
from mycobacteria in the
M. chelonae-M. abscessus
group. The three isolates were significantly more susceptible to clarithromycin, doxycycline, and minocycline than the
M. abscessus
and
M. bolletii
reference strains. One cutaneous isolate and the environmental isolate were in a related cluster by randomly amplified polymorphic DNA PCR (RAPD-PCR). Of the several mycobacterial species found in the day spa, only
M. massiliense
was isolated from biopsy specimens of the skin lesions, suggesting that this bacterium is a human skin pathogen. This is the first known report of cutaneous
M. massiliense
infections that could not be attributed to a prior invasive procedure. This is also the first report of
M. massiliense
infection in Japan.
Adenovirus Infections in Hospitalized Patients in Israel: Epidemiology and Molecular Characterization
Authors: Mandelboim Michal , Dror Pnina , Azar Roberto , Bromberg Michal , Mendelson Ella
Published: December 2010

Adenoviruses can cause a broad spectrum of clinical diseases, most of which are self-limited. However, adenovirus infection can occasionally result in severe or lethal infection. Fifty-five adenovirus serotypes are known today, and they are classified into 7 subgroups (subgroups A to G). Here we examined 282 samples derived from hospitalized patients in Israel (September 2006 to August 2008) who were diagnosed as suffering from adenovirus infections. We used a recently described PCR amplification method and subsequent sequencing to identify the adenovirus. In addition, we studied the medical charts of 106 hospitalized patients from Sheba Medical Center in Israel. The most prevalent adenovirus serotypes found were serotypes 1 (22.8%), 2 (19.2%), 7 (18%), and 3 (14%). In addition, we identified several serotypes that have not been identified previously in Israel. Overall, serotypes of subgroup B were found to be approximately 4 times more prevalent among immunocompromised children than among generally healthy children (52.6%;P< 0.007). The realization that the virus subtypes are different among healthy and immunocompromised patients may lead to more efficient treatment of adenovirus infections among immunocompromised children in the future.
False-Positive Cryptococcal Antigen Test Associated with Use of BBL Port-A-Cul Transport Vials
Authors: Wilson Deborah A. , Sholtis Mary , Parshall Sharon , Hall Gerri S. , Procop Gary W.
Published: December 2010

A total of 52 residual CSF and serum specimens, which were originally negative with the Cryptococcal Antigen Latex Agglutination System (CALAS), were shown to become falsely positive after placement in BBL Port-A-Cul anaerobic transport vials. This transport device, although excellent for specimen transportation for subsequent culture, should not be used if cryptococcal antigen testing is needed.
Can We Use Imipenem and Meropenem Vitek 2 MICs for Detection of Suspected KPC and Other-Carbapenemase Producers among Species of Enterobacteriaceae?
Authors: Pasteran Fernando , Lucero Celeste , Soloaga Rolando , Rapoport Melina , Corso Alejandra
Published: December 2010

Imipenem and meropenem Vitek 2 MICs were evaluated for a panel of 104
Enterobacteriaceae
for identification of carbapenemase producers. The sensitivity and specificity values for the new CLSI interpretative criteria (CLSI document M100-S20-U, 2010) were 98% and 83% for imipenem and 76% and 83% for meropenem, respectively. We propose an algorithm that is highly sensitive (98%) and specific (94%) for carbapenemase screening based on the combined use of imipenem and meropenem MICs.
Most Cases of Cryptococcal Meningitis in HIV-Uninfected Patients in Vietnam Are Due to a Distinct Amplified Fragment Length Polymorphism-Defined Cluster of Cryptococcus neoformans var. grubii VN1
Authors: Day Jeremy N. , Hoang Thu N. , Duong Anh V. , Hong Chau T. T. , Diep Pham T. , Campbell James I. , Sieu Tran P. M. , Hien Tran T. , Bui Tien , Boni Maciej F. , Lalloo David G. , Carter Dee , Baker Stephen , Farrar Jeremy J.
Published: December 2010

Cryptococcal disease most commonly occurs in patients with an underlying immune deficit, most commonly HIV infection, and is due to
Cryptococcus neoformans
var.
grubii
. Occasionally disease due to this variety occurs in apparently immunocompetent patients. The relationship between strains infecting immunosuppressed and immunocompetent patients is not clear. Amplified fragment length polymorphism (AFLP) analysis was used to characterize the relationship between strains infecting HIV-infected and uninfected patients. Isolates from 51 HIV-uninfected patients and 100 HIV-infected patients with cryptococcal meningitis were compared.
C. neoformans
var.
grubii
VNI was responsible for infections in 73% of HIV-uninfected and 100% of HIV-infected patients. AFLP analysis defined two distinct clusters, VNIγ and VNIδ. The majority (84%) of isolates from HIV-uninfected patients were VNIγ, compared with only 38% of isolates from HIV-infected patients (odds ratio, 8.30; 95% confidence interval [CI], 3.04 to 26.6;
P
< 0.0001). In HIV-uninfected patients, underlying disease was less frequent in those with VNIγ infections. Two clusters of
C. neoformans
var.
grubii
VN1 are responsible for the majority of cases of cryptococcal meningitis in Vietnam. The distribution of these clusters differs according to the immune status of the host.
Enhancing Gonococcal Antimicrobial Resistance Surveillance: a Real-Time PCR Assay for Detection of Penicillinase-Producing Neisseria gonorrhoeae by Use of Noncultured Clinical Samples
Authors: Goire Namraj , Freeman Kevin , Tapsall John W. , Lambert Stephen B. , Nissen Michael D. , Sloots Theo P. , Whiley David M.
Published: December 2010

With increasing concerns regarding diminishing treatment options for gonorrhea, maintaining the efficacy of currently used treatments and ensuring optimal
Neisseria gonorrhoeae
antimicrobial resistance surveillance are of the utmost importance. Penicillin is still used to treat gonorrhea in some parts of the world. In this study, we developed and validated a real-time PCR assay for the detection of penicillinase-producing
N. gonorrhoeae
(PPNG) in noncultured clinical samples with the aim of enhancing penicillin resistance surveillance. The assay (PPNG-PCR2) was designed to be an indirect marker of penicillinase activity, by targeting a region of sequence predicted to be conserved across all
N. gonorrhoeae
plasmid types harboring the beta-lactamase gene while not specifically targeting the actual beta-lactamase-encoding sequence. The assay was evaluated by using a total of 118
N. gonorrhoeae
clinical isolates and 1,194 clinical specimens, including 239
N. gonorrhoeae
-positive clinical samples from which
N. gonorrhoeae
cells were isolated and for which phenotypic penicillinase results are available. Overall, the PPNG-PCR2 assay provided 100% sensitivity and 98.7% specificity compared to bacterial culture results for the detection of PPNG in clinical specimens. PPNG-PCR2 false-positive results, presumably due to cross-reactions with unrelated bacterial species, were observed for up to 1.3% of clinical samples but could be distinguished on the basis of high cycle threshold values. In tandem with phenotypic surveillance, the PPNG-PCR2 assay has the potential to provide enhanced epidemiological surveillance of
N. gonorrhoeae
penicillin resistance and is of particular relevance to regions where penicillin is still used to treat gonorrhea.
The Capacity of UL49.5 Proteins To Inhibit TAP Is Widely Distributed among Members of the Genus
Varicellovirus
Authors: Verweij Marieke C. , Lipińska Andrea D. , Koppers-Lalic Danijela , van Leeuwen Wouter F. , Cohen Jeffrey I. , Kinchington Paul R. , Messaoudi Ilhem , Bieńkowska-Szewczyk Krystyna , Ressing Maaike E. , Rijsewijk Frans A. M. , Wiertz Emmanuel J. H. J.
Published: December 2010

The lifelong infection by varicelloviruses is characterized by a fine balance between the host immune response and immune evasion strategies used by these viruses. Virus-derived peptides are presented to cytotoxic T lymphocytes by major histocompatibility complex (MHC) class I molecules. The transporter associated with antigen processing (TAP) transports the peptides from the cytosol into the endoplasmic reticulum, where the loading of MHC-I molecules occurs. The varicelloviruses bovine herpesvirus 1 (BoHV-1), pseudorabies virus, and equid herpesviruses 1 and 4 have been found to encode a UL49.5 protein that inhibits TAP-mediated peptide transport. To investigate to what extent UL49.5-mediated TAP inhibition is conserved within the family of
Alphaherpesvirinae
, the homologs of another five varicelloviruses, one mardivirus, and one iltovirus were studied. The UL49.5 proteins of BoHV-5, bubaline herpesvirus 1, cervid herpesvirus 1, and felid herpesvirus 1 were identified as potent TAP inhibitors. The varicella-zoster virus and simian varicellovirus UL49.5 proteins fail to block TAP; this is not due to the absence of viral cofactors that might assist in this process, since cells infected with these viruses did not show reduced TAP function either. The UL49.5 homologs of the mardivirus Marek's disease virus 1 and the iltovirus infectious laryngotracheitis virus did not block TAP, suggesting that the capacity to inhibit TAP via UL49.5 has been acquired by varicelloviruses only. A phylogenetic analysis of viruses that inhibit TAP through their UL49.5 proteins reveals an interesting hereditary pattern, pointing toward the presence of this capacity in defined clades within the genus
Varicellovirus
.
Inclusion of the Central Exon of Parvovirus B19 Precursor mRNA Is Determined by Multiple Splicing Enhancers in both the Exon and the Downstream Intron
Authors: Guan Wuxiang , Cheng Fang , Huang Qinfeng , Kleiboeker Steve , Qiu Jianming
Published: December 2010

Alternative splicing of the precursor mRNA (pre-mRNA) of human parvovirus B19 (B19V) plays a key role in posttranscriptional regulation of B19V gene expression. We report that the central exon of the B19V pre-mRNA is defined by three GAA motif-containing exonic splicing enhancers and a G/GU-rich intronic splicing enhancer that lies adjacent to the second donor site. Moreover, targeting of morpholino antisense oligonucleotides to the two splicing enhancers surrounding the second donor site led to a significant reduction in splicing at this donor site during B19V infection of permissive CD36
+
erythroid progenitor cells.
Antiviral Activity of Human Immunodeficiency Virus Type 1 Gag-Specific Cytotoxic T Lymphocyte Targeting Is Not Necessarily Intrinsically Superior to Envelope Targeting
Authors: Chen Diana Y. , Balamurugan Arumugam , Ng Hwee L. , Yang Otto O.
Published: December 2010

Across several cohorts, human immunodeficiency virus type 1 (HIV-1) Gag- and Env-specific CD8
+
T lymphocyte (CTL) responses have demonstrated inverse and positive correlations, respectively, to viremia. The mechanism has been proposed to be superior antiviral activity of Gag-specific CTLs in general. Addressing this hypothesis, we created two HIV-1 constructs with an epitope translocated from Gag (SLYNTVATL, SL9) to Env, thereby switching the protein source of the epitope. A virus expressing SL9 in Env was similar to the original virus in susceptibility to SL9-specific CTLS. This finding suggests that Env targeting is not intrinsically inferior to Gag targeting for CTL antiviral activity.
A PDI Family Network Acts Distinctly and Coordinately with ERp29 To Facilitate Polyomavirus Infection
Authors: Walczak Christopher P. , Tsai Billy
Published: December 2010

Endoplasmic reticulum (ER)-to-cytosol membrane transport is a decisive infection step for the murine polyomavirus (Py). We previously determined that ERp29, a protein disulfide isomerase (PDI) member, extrudes the Py VP1 C-terminal arm to initiate ER membrane penetration. This reaction requires disruption of Py's disulfide bonds. Here, we found that the PDI family members ERp57, PDI, and ERp72 facilitate virus infection. However, while all three proteins disrupt Py's disulfide bonds
in vitro
, only ERp57 and PDI operate in concert with ERp29 to unfold the VP1 C-terminal arm. An alkylated Py cannot stimulate infection, implying a pivotal role of viral free cysteines during infection. Consistent with this, we found that although PDI and ERp72 reduce Py, ERp57 principally isomerizes the virus
in vitro
, a reaction that requires viral free cysteines. Our mutagenesis study subsequently identified VP1 C11 and C15 as important for infection, suggesting a role for these residues during isomerization. C11 and C15 also act together to stabilize interpentamer interactions for a subset of the virus pentamers, likely because some of these residues form interpentamer disulfide bonds. This study reveals how a PDI family functions coordinately and distinctly to promote Py infection and pinpoints a role of viral cysteines in this process.
Abnormal fibrillin-1 expression and chronic oxidative stress mediate endothelial mesenchymal transition in a murine model of systemic sclerosis
Authors: Xu Hao , Zaidi Maria , Struve Janine , Jones Deron W. , Krolikowski John G. , Nandedkar Sandhya , Lohr Nicole L. , Gadicherla Ashish , Pagel Paul S. , Csuka Mary Ellen , Pritchard Kirkwood A. , Weihrauch Dorothée
Published: December 2010

Systemic sclerosis (SSc) is an autoimmune connective tissue disorder characterized by oxidative stress, impaired vascular function, and attenuated angiogenesis. The tight-skin (Tsk−/+) mouse is a model of SSc that displays many of the cellular features of the clinical disease. We tested the hypotheses that abnormal fibrillin-1 expression and chronic phospholipid oxidation occur in Tsk−/+ mice and, furthermore, that these factors precipitate a prooxidant state, collagen-related protein expression, apoptosis, and mesenchymal transition in endothelial cells cultured on Tsk−/+ extracellular matrix. Human umbilical vein endothelial cells were seeded on microfibrils isolated from skin of C57BL/6J (control) and Tsk−/+ mice in the presence or absence of chronic pretreatment with the apolipoprotein Apo A-I mimetic D-4F (1 mg·kg−1·day−1 ip for 6 to 8 wk). Nitric oxide-to-superoxide anion ratio was assessed 12 h after culture, and cell proliferation, apoptosis, and phenotype were studied 72 h after culture. Tsk−/+ mice demonstrated abnormal “big fibrillin” expression (405 kDa) by Western blot analysis compared with control. Endothelial cells cultured on microfibrils prepared from Tsk−/+ mice demonstrated reduced proliferation, a prooxidant state (reduced nitric oxide-to-superoxide anion ratio), increased apoptosis, and collagen-related protein expression associated with mesenchymal transition. Chronic D-4F pretreatment of Tsk−/+ mice attenuated many of these adverse effects. The findings demonstrate that abnormal fibrillin-1 expression and chronic oxidative stress mediate endothelial mesenchymal transition in Tsk−/+ mice. This mesenchymal transition may contribute to the reduction in angiogenesis that is known to occur in this model of SSc.
C. elegans STK39/SPAK ortholog-mediated inhibition of ClC anion channel activity is regulated by WNK-independent ERK kinase signaling
Authors: Falin Rebecca A. , Miyazaki Hiroaki , Strange Kevin
Published: December 2010

Mammalian Ste20-like proline/alanine-rich kinase (SPAK) and oxidative stress-responsive 1 (OSR1) kinases phosphorylate and regulate cation-coupled Cl− cotransporter activity in response to cell volume changes. SPAK and OSR1 are activated via phosphorylation by upstream with-no-lysine (WNK) kinases. In Caenorhabditis elegans, the SPAK/OSR1 ortholog germinal center kinase (GCK)-3 binds to and regulates the activity of the cell volume- and meiotic cell cycle-dependent ClC anion channel CLH-3b. We tested the hypothesis that WNK kinases function in the GCK-3/CLH-3b signaling cascade. CLH-3b heterologously expressed in human embryonic kidney (HEK) cells was unaffected by coexpression with the single C. elegans WNK kinase, WNK-1, or kinase-dead WNK-1 dominant-negative mutants. RNA interference (RNAi) knockdown of the single Drosophila WNK kinase had no effect on the activity of CLH-3b expressed in Drosophila S2 cells. Similarly, RNAi silencing of C. elegans WNK-1 had no effect on basal or cell volume-sensitive activity of CLH-3b expressed endogenously in worm oocytes. Previous yeast 2-hybrid studies suggested that ERK kinases may function upstream of GCK-3. Pharmacological inhibition of ERK signaling disrupted CLH-3b activity in HEK cells in a GCK-3-dependent manner. RNAi silencing of the C. elegans ERK kinase MPK-1 or the ERK phosphorylating/activating kinase MEK-2 constitutively activated native CLH-3b. MEK-2 and MPK-1 play important roles in regulating the meiotic cell cycle in C. elegans oocytes. Cell cycle-dependent changes in MPK-1 correlate with the pattern of CLH-3b activation observed during oocyte meiotic maturation. We postulate that MEK-2/MPK-1 functions upstream from GCK-3 to regulate its activity during cell volume and meiotic cell cycle changes.
Cortactin activation by FVIIa/tissue factor and PAR2 promotes endothelial cell migration
Authors: Zhu Tang , Mancini Joseph A. , Sapieha Przemyslaw , Yang Chun , Joyal Jean-Sébastien , Honoré Jean-Claude , Leduc Martin , Zaniolo Karine , Hardy Pierre , Shao Zhuo , Fan Li , Hou Xin , Rivard Georges-Etienne , Chemtob Sylvain
Published: December 2010

Cellular migration is a complex process that requires the polymerization of actin filaments to drive cellular extension. Smooth muscle and cancer cell migration has been shown to be affected by coagulation factors, notably the factor VII (FVIIa) and tissue factor (TF) complex. The present studies delineated mediators involved with the process of FVIIa/TF-induced cell migration and utilized a simple, precise, and reproducible, migration assay. Both FVIIa and protease-activated receptor-2 (PAR2)-activating peptide, SLIGRL, increased the migration rate of porcine cerebral microvascular endothelial cells (pCMVECs) overexpressing human TF. Ras homolog gene family member A (RhoA) and cortactin were upregulated during the process; expression of HIF, actin polymerization nuclear diaphanous-related formin-1 and -2 (Dia1, and Dia2) were unaffected. Gene silencing by shRNA to PAR2, RhoA, and cortactin attenuated this gene upregulation and migration induced by FVIIa/TF. Utilizing immunocellular localization, we demonstrate that during FVIIa/TF and PAR2 activation, cortactin molecules translocate from the cytoplasm to the cell periphery and assist in lamellipodia formation of pCMVECs. Overall, we demonstrate a novel regulation and role for cortactin in FVIIa/TF-mediated endothelial cell migration that occurs through a PAR2 and RhoA dependent mechanism.
Factors associated with purity, biological function, and activation potential of endothelial colony-forming cells
Authors: Wang Chao-Hung , Hsieh I-Chang , Su Pang Jong-Hwei , Cherng Wen-Jin , Lin Shing-Jong , Tung Tao-Hsin , Mei Hsiu-Fu
Published: December 2010

Endothelial colony-forming cells (ECFCs) are undergoing extensive investigations to tackle certain deliberating cardiovascular diseases. However, the success of this approach depends on a thorough understanding of ECFC biology. This study sought to determine the factors associated with the purity, biological function, and activation potential of ex vivo expanded ECFCs. Seventy-three patients with newly diagnosed coronary artery disease (CAD) and 24 controls were studied. ECFCs were cultured for up to 10 passages to investigate changes in and the impact of coronary risk factors on ECFC biological functions and the atherogenic potential. Passages 3–5 of ECFCs exhibited higher endothelial phenotype expression and better biological functions, in terms of nitric oxide secretion and tubular formation, but lower activation potentials compared with later passages ( P <0.05). Studies on passage 3 showed that endothelial phenotype expression and biological functions were impaired, and the activation potentials of the ECFCs were significantly upregulated in subjects with coronary risk factors and especially those with CAD ( P < 0.05). Furthermore, ECFCs were already activated before inflammatory stimulation in subjects with diabetes mellitus, hypertension, and CAD. Atorvastatin upregulated the endothelial nitric oxide synthase expression of ECFCs in CAD patients ( P < 0.01), although not up to the baseline level of controls. In conclusion, the passage number and a variety of coronary risk factors were associated with the purity, biological function, and activation potential of ex vivo-expanded ECFCs. Functional assessments and manipulations of ECFCs have to be pursued in patients with extensive risk factors.
Identifying cardiovascular neurocircuitry involved in the exercise pressor reflex in humans using functional neurosurgery
Authors: Basnayake Shanika D. , Hyam Jonathan A. , Pereira Erlick A. , Schweder Patrick M. , Brittain John-Stuart , Aziz Tipu Z. , Green Alexander L. , Paterson David J.
Published: December 2010

Groups III and IV afferents carry sensory information regarding the muscle exercise pressor reflex, although the central integrating circuits of the reflex in humans are still poorly defined. Emerging evidence reports that the periaqueductal gray (PAG) could be a major site for integrating the “central command” component that initiates the cardiovascular response to exercise, since this area is activated during exercise and direct stimulation of the dorsal PAG causes an increase in arterial blood pressure (ABP) in humans. Here we recorded local field potentials (LFPs) from various “deep” brain nuclei during exercise tasks designed to elicit the muscle pressor reflex. The patients studied had undergone neurosurgery for the treatment of movement or pain disorders, thus had electrodes implanted stereotactically either in the PAG, subthalamic nucleus, globus pallidus interna, thalamus, hypothalamus, or anterior cingulate cortex. Fast Fourier transform analysis was applied to the neurograms to identify the power of fundamental spectral frequencies. Our PAG patients showed significant increases in LFP power at frequencies from 4 to 8 Hz ( P < 0.01), 8 to 12 Hz ( P < 0.001), and 12 to 25 Hz ( P < 0.001). These periods were associated with maintained elevated ABP during muscle occlusion following exercise. Further increases in exercise intensity resulted in corresponding increases in PAG activity and ABP. No significant changes were seen in the activity of other nuclei during occlusion. These electrophysiological data provide direct evidence for a role of the PAG in the integrating neurocircuitry of the exercise pressor reflex in humans.
Superoxide anions in the paraventricular nucleus mediate the enhanced cardiac sympathetic afferent reflex and sympathetic activity in renovascular hypertensive rats
Authors: Han Ying , Fan Zhi-Dan , Yuan Ning , Xie Gui-Qin , Gao Juan , De Wei , Gao Xing-Ya , Zhu Guo-Qing
Published: December 2010

An enhanced cardiac sympathetic afferent reflex (CSAR) is involved in the sympathetic activation in renovascular hypertension. The present study was designed to determine the role of superoxide anions in the paraventricular nucleus (PVN) in mediating the enhanced CSAR and sympathetic activity in renovascular hypertension in the two-kidney, one-clip (2K1C) model. Sinoaortic denervation and vagotomy were carried out, and renal sympathetic nerve activity (RSNA) and mean arterial pressure (MAP) were recorded under anesthesia. The CSAR was evaluated by the response of RSNA to the epicardial application of capsaicin. Superoxide anion levels and NAD(P)H oxidase activity in the PVN increased in 2K1C rats and were much higher in 2K1C rats than in sham-operated (sham) rats after the epicardial application of capsaicin or PVN microinjection of ANG II. In both 2K1C and sham rats, PVN microinjection of the superoxide anion scavenger tempol or the NAD(P)H oxidase inhibitor apocynin abolished the CSAR, whereas the SOD inhibitor diethyldithiocarbamic acid (DETC) potentiated the CSAR. Tempol and apocynin decreased but DETC increased baseline RSNA and MAP. ANG II in the PVN caused larger responses of the CSAR, baseline RSNA, and baseline MAP in 2K1C rats than in sham rats. The effects of ANG II were abolished by pretreatment with tempol or apocynin in both 2K1C and sham rats and augmented by DETC in the PVN in 2K1C rats. These results indicate that superoxide anions in the PVN mediate the CSAR and the effects of ANG II in the PVN. Increased superoxide anions in the PVN contribute to the enhanced CSAR and sympathetic activity in renovascular hypertension.
Effects of Vision Restoration Training on Early Visual Cortex in Patients With Cerebral Blindness Investigated With Functional Magnetic Resonance Imaging
Authors: Raemaekers M. , Bergsma D. P. , van Wezel R. J. A. , van der Wildt G. J. , van den Berg A. V.
Published: December 2010

Cerebral blindness is a loss of vision as a result of postchiasmatic damage to the visual pathways. Parts of the lost visual field can be restored through training. However, the neuronal mechanisms through which training effects occur are still unclear. We therefore assessed training-induced changes in brain function in eight patients with cerebral blindness. Visual fields were measured with perimetry and retinotopic maps were acquired with functional magnetic resonance imaging (fMRI) before and after vision restoration training. We assessed differences in hemodynamic responses between sessions that represented changes in amplitudes of neural responses and changes in receptive field locations and sizes. Perimetry results showed highly varied visual field recovery with shifts of the central visual field border ranging between 1 and 7°. fMRI results showed that, although retinotopic maps were mostly stable over sessions, there was a small shift of receptive field locations toward a higher eccentricity after training in addition to increases in receptive field sizes. In patients with bilateral brain activation, these effects were stronger in the affected than in the intact hemisphere. Changes in receptive field size and location could account for limited visual field recovery (±1°), although it could not account for the large increases in visual field size that were observed in some patients. Furthermore, the retinotopic maps strongly matched perimetry measurements before training. These results are taken to indicate that local visual field enlargements are caused by receptive field changes in early visual cortex, whereas large-scale improvement cannot be explained by this mechanism.
Discharge Characteristics of Biceps Brachii Motor Units at Recruitment When Older Adults Sustained an Isometric Contraction
Authors: Pascoe Michael A. , Holmes Matthew R. , Enoka Roger M.
Published: December 2010

The purpose of this study was to compare the discharge characteristics of motor units recruited during an isometric contraction that was sustained with the elbow flexor muscles by older adults at target forces that were less than the recruitment threshold force of each isolated motor unit. The discharge times of 27 single motor units were recorded from the biceps brachii in 11 old adults (78.8 ± 5.9 yr). The target force was set at either a relatively small (6.6 ± 3.7% maximum) or large (11.4 ± 4.5% maximum) difference below the recruitment threshold force and the contraction was sustained until the motor unit was recruited and discharged action potentials for about 60 s. The time to recruitment was longer for the large target-force difference ( P = 0.001). At recruitment, the motor units discharged repetitively for both target-force differences, which contrasts with data from young adults when motor units discharged intermittently at recruitment for the large difference between recruitment threshold force and target force. The coefficient of variation (CV) for the first five interspike intervals (ISIs) increased from the small (18.7 ± 7.9) to large difference (35.0 ± 10.2%, P = 0.008) for the young adults, but did not differ for the two target force differences for the old adults (26.3 ± 14.7 to 24.0 ± 13.1%, P = 0.610). When analyzed across the discharge duration, the average CV for the ISI decreased similarly for the two target-force differences ( P = 0.618) in old adults. These findings contrast with those of young adults and indicate that the integration of synaptic input during sustained contractions differs between young and old adults.
Severe Spasm of the Renal Artery after Blunt Abdominal Trauma Simulating End-Organ Infarction
Authors: Ucar Adem , Yahyayev Aghakishi , Agayev Ayaz , Yanar Fatih , Bakan Selim , Bulakci Mesut , Akman Tolga , Yekeler Ensar
Published: December 2010

Traumatic occlusion of the renal artery is a serious injury. Management differs according to the grade of injury. In most circumstances, emergency surgical revascularization or endovascular intervention is required. We describe the case of a child with multiorgan injuries and spasm of the main renal artery after blunt trauma simulating arterial occlusion or end-organ infarction.
Posttranslational Processing and Modification of Cathepsins and Cystatins
Authors: Katunuma Nobuhiko
Published: December 2010

Cathepsins are an essential protease family in all living cells. The cathepsins play an essential roles such as protein catabolism and protein synthesis. To targeting to various organella and to regulate their activity, the post translational-processing and modification play an important role Cathepsins are translated in polysome as the pre-pro-mature forms. The pre-peptide is removed cotranslationally and then translocated to Golgi-apparatus and the pro-part is removed and the mature-part is glycosylated, and the mature-part is targeted into the lysosome mediated by mannose-6-phosphate signal and the mature-part is bound with their coenzymes. The degradation of the mature-part is started by the limited proteolysis of the ordered nicked bonds to make hydrophobic peptides. The peptides are incorporated into phagosome or proteasome after ubiquitinated and are degrade into amino-acids. Cystatins are endogenous inhibitors of cathepsins. Cystatinαwhich is only located in skin is phosphorylated at the near C-terminus by protein kinase-C, and the phosphorylate-cystatinαis incorporated into cornified envelope and conjugated with filaggrin-fiber by transglutaminase to form the linker-fiber of skin. The cystatinαis modified by glutathione or make their dimmer, and they are inactive. Those modifications are regulated by the redox-potential by the glutathione.
Severe Hypercalcemia and Acute Renal Failure: An Unusual Presentation of Sarcoidosis
Authors: Karnchanasorn Rudruidee , Sarikonda Molly , Aldasouqi Saleh , Gossain Ved V.
Published: December 2010

Although hypercalcemia is a known metabolic complication of sarcoidosis, it is rarely a presenting manifestation. Long-standing hypercalcemia and hypercalciuria can cause nephrocalcinosis and chronic renal failure. Acute renal failure, although described, is also a rare presentation of patients with sarcoidosis. We describe two patients with sarcoidosis, who presented with severe hypercalcemia and worsening renal function. Parathyroid hormone levels were appropriately suppressed. This led to an extensive search for the cause of hypercalcemia. Finally, after a lymph node biopsy in both cases, a diagnosis of sarcoidosis was established, hypercalcemia resolved, and renal function improved in both cases after administration of prednisone.