bluuebunny/crossref_metadata_2025 huggingface dataset:
Design Loads Used for Direct Strength Assessment of Merchant Ship Structures
Authors: Zhu Tingyao , Shigemi Toshiyuki
Published: May 2007

This paper summarizes the results of extensive research on the design loads used for strength assessment of merchant ship structures such as tankers, bulk carriers, and container ships. The main aim of the research was to develop practical estimation methods of design loads having rational technical backgrounds acting on primary structural members of tankers, bulk carriers, and container ships. During this study we will do the following. (1) The design sea states that closely resemble the actual sea states which are considered as the most severe for hull structures are proposed. (2) The practical estimation methods of the design sea states are proposed by parametric studies using the results of series calculation of representative merchant ships. (3) The practical estimation methods of design regular waves resulting in the same level of stresses as that induced in irregular waves under the design sea states are proposed. (4) The practical estimation methods of the design loads such as ship motions, accelerations, hull-girder bending moments, and hydrodynamic pressures that are induced under design regular waves are briefly introduced. The findings in this study have been summarized and implemented in the new design standards for tanker, bulk carrier, and container ship structures (“Guidelines for Tanker Structures,” 2001, Nippon Kaiji Kyokai; “Guidelines for Bulk Carrier Structures,” 2002, Nippon Kaiji Kyokai; “Guidelines for Container Carrier Structures,” 2003, Nippon Kaiji Kyokai).
GRACE Gravity Data Constrain Ancient Ice Geometries and Continental Dynamics over Laurentia
Authors: Tamisiea M. E. , Mitrovica J. X. , Davis J. L.
Published: May 2007

The free-air gravity trend over Canada, derived from the Gravity Recovery and Climate Experiment (GRACE) satellite mission, robustly isolates the gravity signal associated with glacial isostatic adjustment (GIA) from the longer–time scale mantle convection process. This trend proves that the ancient Laurentian ice complex was composed of two large domes to the west and east of Hudson Bay, in accord with one of two classes of earlier reconstructions. Moreover, GIA models that reconcile the peak rates contribute ∼25 to ∼45% to the observed static gravity field, which represents an important boundary condition on the buoyancy of the continental tectosphere.
The Process of Tholin Formation in Titan's Upper Atmosphere
Authors: Waite J. H. , Young D. T. , Cravens T. E. , Coates A. J. , Crary F. J. , Magee B. , Westlake J.
Published: May 2007

Titan's lower atmosphere has long been known to harbor organic aerosols (tholins) presumed to have been formed from simple molecules, such as methane and nitrogen (CH
4
and N
2
). Up to now, it has been assumed that tholins were formed at altitudes of several hundred kilometers by processes as yet unobserved. Using measurements from a combination of mass/charge and energy/charge spectrometers on the Cassini spacecraft, we have obtained evidence for tholin formation at high altitudes (∼1000 kilometers) in Titan's atmosphere. The observed chemical mix strongly implies a series of chemical reactions and physical processes that lead from simple molecules (CH
4
and N
2
) to larger, more complex molecules (80 to 350 daltons) to negatively charged massive molecules (∼8000 daltons), which we identify as tholins. That the process involves massive negatively charged molecules and aerosols is completely unexpected.
The Role of Wheat Awns in the Seed Dispersal Unit
Authors: Elbaum Rivka , Zaltzman Liron , Burgert Ingo , Fratzl Peter
Published: May 2007

The dispersal unit of wild wheat bears two pronounced awns that balance the unit as it falls. We discovered that the awns are also able to propel the seeds on and into the ground. The arrangement of cellulose fibrils causes bending of the awns with changes in humidity. Silicified hairs that cover the awns allow propulsion of the unit only in the direction of the seeds. This suggests that the dead tissue is analogous to a motor. Fueled by the daily humidity cycle, the awns induce the motility required for seed dispersal
Pairing Without Superfluidity: The Ground State of an Imbalanced Fermi Mixture
Authors: Schunck C. H. , Shin Y. , Schirotzek A. , Zwierlein M. W. , Ketterle W.
Published: May 2007

We used radio-frequency spectroscopy to study pairing in the normal and superfluid phases of a strongly interacting Fermi gas with imbalanced spin populations. At high spin imbalances, the system does not become superfluid even at zero temperature. In this normal phase, full pairing of the minority atoms was observed. Hence, mismatched Fermi surfaces do not prevent pairing but can quench the superfluid state, thus realizing a system of fermion pairs that do not condense even at the lowest temperature.
Regulation of B Versus T Lymphoid Lineage Fate Decision by the Proto-Oncogene LRF
Authors: Maeda Takahiro , Merghoub Taha , Hobbs Robin M. , Dong Lin , Maeda Manami , Zakrzewski Johannes , van den Brink Marcel R.M. , Zelent Arthur , Shigematsu Hirokazu , Akashi Koichi , Teruya-Feldstein Julie , Cattoretti Giorgio , Pandolfi Pier Paolo
Published: May 2007

Hematopoietic stem cells in the bone marrow give rise to lymphoid progenitors, which subsequently differentiate into B and T lymphocytes. Here we show that the proto-oncogene
LRF
plays an essential role in the B versus T lymphoid cell-fate decision. We demonstrate that
LRF
is key for instructing early lymphoid progenitors in mice to develop into B lineage cells by repressing T cell–instructive signals produced by the cell-fate signal protein, Notch. We propose a new model for lymphoid lineage commitment, in which LRF acts as a master regulator of the cell's determination of B versus T lineage.
Functional and Specific Antibody Responses in Adult Volunteers in New Zealand Who Were Given One of Two Different Meningococcal Serogroup B Outer Membrane Vesicle Vaccines
Authors: Wedege E. , Bolstad K. , Aase A. , Herstad T. K. , McCallum L. , Rosenqvist E. , Oster P. , Martin D.
Published: May 2007

This study presents detailed analyses of total and specific serum antibody levels among 26 and 24 adult volunteers before vaccination and after the third dose of the meningococcal serogroup B outer membrane vesicle (OMV) vaccines MeNZB and MenBvac, respectively, in a clinical trial in New Zealand (V. Thornton, D. Lennon, K. Rasanathan, J. O'Hallahan, P. Oster, J. Stewart, S. Tilman, I. Aaberge, B. Feiring, H. Nokleby, E. Rosenqvist, K. White, S. Reid, K. Mulholland, M. J. Wakefield, and D. Martin, Vaccine 24:1395-1400, 2006). With the homologous vaccine strains as targets, both vaccines induced significant increases in serum bactericidal and opsonophagocytic activities and in the levels of immunoglobulin G (IgG) to OMV antigens in an enzyme-linked immunosorbent assay (ELISA) and to live meningococci by flow cytometry. They also induced high levels of activity against the heterologous strains, particularly in terms of opsonophagocytic activity and IgG binding to live bacteria. The antibody levels with the homologous and heterologous strains in the four assays showed high and significant positive correlations. Specific IgG binding to 10 major OMV antigens in each vaccine was measured by scanning of immunoblots; ELISAs for two antigens, lipopolysaccharide and
Neisseria
surface protein A (NspA), were also performed. Both vaccines elicited significant increases in IgG binding to all homologous and heterologous OMV antigens except NspA. The total IgG band intensity on the blots correlated significantly with the IgG levels determined by the OMV ELISA and flow cytometry. In conclusion, the results of the various immunological assays showed that both OMV vaccines gave rise to high levels of specific and cross-reacting antibodies.
Lipopolysaccharide Analogs Improve Efficacy of Acellular Pertussis Vaccine and Reduce Type I Hypersensitivity in Mice
Authors: Geurtsen Jeroen , Banus H. Alexander , Gremmer Eric R. , Ferguson Henke , de la Fonteyne-Blankestijn Liset J. J. , Vermeulen Jolanda P. , Dormans Jan A. M. A. , Tommassen Jan , van der Ley Peter , Mooi Frits R. , Vandebriel Rob J.
Published: May 2007

Pertussis is an infectious disease of the respiratory tract that is caused by the gram-negative bacterium
Bordetella pertussis
. Although acellular pertussis (aP) vaccines are safe, they are not fully effective and thus require improvement. In contrast to whole-cell pertussis (wP) vaccines, aP vaccines do not contain lipopolysaccharide (LPS). Monophosphoryl lipid A (MPL) and
Neisseria meningitidis
LpxL2 LPS have been shown to display immune-stimulating activity while exerting little endotoxin activity. Therefore, we evaluated whether these LPS analogs could increase the efficacy of the aP vaccine. Mice were vaccinated with diphtheria-tetanus-aP vaccine with aluminum, MPL, or LpxL2 LPS adjuvant before intranasal challenge with
B. pertussis
. Compared to vaccination with the aluminum adjuvant, vaccination with either LPS analog resulted in lower colonization and a higher pertussis toxin-specific serum immunoglobulin G level, indicating increased efficacy. Vaccination with either LPS analog resulted in reduced lung eosinophilia, reduced eosinophil numbers in the bronchoalveolar lavage fluid, and the ex vivo production of interleukin-4 (IL-4) by bronchial lymph node cells and IL-5 by spleen cells, suggesting reduced type I hypersensitivity. Vaccination with either LPS analog increased serum IL-6 levels, although these levels remained well below the level induced by wP, suggesting that supplementation with LPS analogs may induce some reactogenicity but reactogenicity considerably less than that induced by the wP vaccine. In conclusion, these results indicate that supplementation with LPS analogs forms a promising strategy that can be used to improve aP vaccines.
Use of CultureSwab Plus Swabs with Amies Gel Agar for Testing of Naris Specimens with the GeneOhm MRSA Assay
Authors: Bourbeau P. P. , Riley J. A. , Shoemaker B. C. , Jones K. S.
Published: May 2007

The GeneOhm MRSA assay detects nasal colonization with methicillin-resistant
Staphylococcus aureus
(MRSA). We compared the use of seeded swabs with liquid Stuart's medium and that of seeded swabs with Amies gel for the assay. Overall, the swabs with liquid Stuart's medium detected significantly greater numbers of MRSA than the swabs with Amies gel (
P
= 0.0003).
Comparison of the Digene Hybrid Capture 2 Assay and Roche AMPLICOR and LINEAR ARRAY Human Papillomavirus (HPV) Tests in Detecting High-Risk HPV Genotypes in Specimens from Women with Previous Abnormal Pap Smear Results
Authors: Stevens Matthew P. , Garland Suzanne M. , Rudland Elice , Tan Jeffrey , Quinn Michael A. , Tabrizi Sepehr N.
Published: May 2007

The development of cervical cancer is strongly associated with the presence of persistent high-risk (HR) human papillomavirus (HPV) infection. Recently, the commercially manufactured PCR-based Roche AMPLICOR (AMP) and LINEAR ARRAY (LA) HPV tests have become available for HPV detection. However, knowledge of their clinical performance compared to the U.S. Food and Drug Administration-approved Hybrid Capture 2 (HC2) assay is limited. This study evaluated the concordance between the HC2, AMP, and LA tests in detecting HR-HPV among a cohort of 1,679 women with previous abnormal Pap smear results. Overall, 1,393 specimens (81.3%) generated concordant results for HR-HPV presence or absence by the three assays. The concordance levels were substantial between the HC2 and AMP tests (84.4%, κ = 0.6419) and between the HC2 and LA tests (84.0%, κ = 0.6341) and nearly perfect between the AMP and LA tests (97.8%, κ = 0.9441). HR-HPV prevalence, as detected by the AMP or LA tests, was significantly higher among women with cytological or histological high-grade disease (CIN2 or greater) than that detected by HC2 (
P
< 0.0001). The AMP and LA tests exhibited greater sensitivity, but lower specificity, than HC2 for detecting HR-HPV among this cohort of women with underlying cervical abnormalities, particularly among subjects with histologically proven high-grade disease. Both PCR-based HPV tests may be valuable in the management of care for women with underlying cervical abnormalities, in predicting treatment success, and in studying the clearance or acquisition of new infections.
Protracted Course of Lymphocytic Choriomeningitis Virus WE Infection in Early Life: Induction but Limited Expansion of CD8+Effector T Cells and Absence of Memory CD8+T Cells
Authors: Belnoue Elodie , Fontannaz-Bozzotti Paola , Grillet Stéphane , Lambert Paul-Henri , Siegrist Claire-Anne
Published: May 2007

Viral infections in human infants frequently follow a protracted course, with higher viral loads and delayed viral clearance compared to viral infections in older children. To identify the mechanisms responsible for this protracted pattern of infection, we developed an infant infection murine model using the well-characterized lymphocytic choriomeningitis virus (LCMV) WE strain in 2-week-old BALB/c mice. In contrast to adult mice, in which viral clearance occurred as expected 8 days after infection, LCMV titers persisted for several weeks after infection of infant mice. LCMV-specific effector CD8+T cells were elicited in infant mice and fully functional on day 7 but rapidly waned and could not be recovered from day 12 onwards. We show here that this results from the failure of LCMV-specific CD8+T cells to expand and the absence of protective LCMV-specific memory CD8+T cells. Under these early life conditions, viral control and clearance are eventually achieved only through LCMV-specific B cells that contribute to protect infant mice from early death or chronic infection.
Investigation of Adenovirus Occurrence in Pediatric Tumor Entities
Authors: Kosulin Karin , Haberler Christine , Hainfellner Johannes A. , Amann Gabriele , Lang Susanna , Lion Thomas
Published: May 2007

Adenoviruses (AdVs) contain genes coding for proteins with transforming potential, and certain AdV serotypes have been shown to induce tumors in rodents. However, data on the possible oncogenicity of AdVs in humans are scarce. We have therefore employed a real-time quantitative PCR (RQ-PCR) assay permitting highly sensitive detection of all 51 currently known human AdV serotypes to screen more than 500 tumor specimens derived from 17 different childhood cancer entities including leukemias, lymphomas, and solid tumors. Most tumor entities analyzed showed no evidence for the presence of AdV sequences, but AdV DNA was detected by RQ-PCR in different brain tumors including 25/30 glioblastomas, 22/30 oligodendrogliomas, and 20/30 ependymomas. Nonmalignant counterparts of AdV-positive brain tumors, including specimens of ependymal cells, plexus choroideus, and periventricular white matter, were screened for control purposes and revealed the presence of AdV DNA in most specimens tested. Identification of the AdV types present in positive malignant and nonmalignant brain tissue specimens revealed predominantly representatives of species B and D and, less commonly, C. To exclude contamination as a possible cause of false-positive results, specimens with AdV sequences detectable by PCR were subsequently analyzed by in situ hybridization, which confirmed the PCR findings in all instances. The central nervous system appears to represent a common site of AdV infection with virus persistence, thus providing the first evidence for the possible contribution of AdVs to the multistep process of tumor pathogenesis in brain tissue.
Analysis of Ribavirin Mutagenicity in Human Hepatitis C Virus Infection
Authors: Chevaliez Stéphane , Brillet Rozenn , Lázaro Ester , Hézode Christophe , Pawlotsky Jean-Michel
Published: May 2007

The addition of ribavirin to alpha interferon therapy significantly increases response rates for patients with chronic hepatitis C virus (HCV) infection, but ribavirin's antiviral mechanisms are unknown. Ribavirin has been suggested to have mutagenic potential in vitro that would lead to “error catastrophe,” i.e., the generation of nonviable viral quasispecies due to the increment in the number of mutant genomes, which prevents the transmission of meaningful genetic information. We used extensive sequence-based analysis of two independent genomic regions in order to test in vivo the hypothesis that ribavirin administration accelerates the accumulation of mutations in the viral genome and that this acceleration occurs only when HCV replication is profoundly inhibited by coadministered alpha interferon. The rate of variation of the consensus sequence, the frequency of mutation, the error generation rate, and the between-sample genetic distance were measured for patients receiving ribavirin monotherapy, a combination of alpha interferon three times per week plus ribavirin, or a combination of alpha interferon daily plus ribavirin. Ribavirin monotherapy did not increase the rate of variation of the consensus sequence, the mutation frequency, the error generation rate, or the between-sample genetic distance. The accumulation of nucleotide substitutions did not accelerate, relative to the pretreatment period, during combination therapy with ribavirin and alpha interferon, even when viral replication was profoundly inhibited by alpha interferon. This study strongly undermines the hypothesis whereby ribavirin acts as an HCV mutagen in vivo.
CD163 Expression Confers Susceptibility to Porcine Reproductive and Respiratory Syndrome Viruses
Authors: Calvert Jay G. , Slade David E. , Shields Shelly L. , Jolie Rika , Mannan Ramasamy M. , Ankenbauer Robert G. , Welch Siao-Kun W.
Published: May 2007

Direct functional screening of a cDNA expression library derived from primary porcine alveolar macrophages (PAM) revealed that CD163 is capable of conferring a porcine reproductive and respiratory syndrome virus (PRRSV)-permissive phenotype when introduced into nonpermissive cells. Transient-transfection experiments showed that full-length CD163 cDNAs from PAM, human U937 cells (histiocytic lymphoma), African green monkey kidney cells (MARC-145 and Vero), primary mouse peritoneal macrophages, and canine DH82 (histocytosis) cells encode functional virus receptors. In contrast, CD163 splice variants without the C-terminal transmembrane anchor domain do not provide PRRSV receptor function. We established several stable cell lines expressing CD163 cDNAs from pig, human, and monkey, using porcine kidney (PK 032495), feline kidney (NLFK), or baby hamster kidney (BHK-21) as the parental cell lines. These stable cell lines were susceptible to PRRSV infection and yielded high titers of progeny virus. Cell lines were phenotypically stable over 80 cell passages, and PRRSV could be serially passed at least 60 times, yielding in excess of 10
5
50% tissue culture infective doses/ml.
Induction of MxA Gene Expression by Influenza A Virus Requires Type I or Type III Interferon Signaling
Authors: Holzinger Dirk , Jorns Carl , Stertz Silke , Boisson-Dupuis Stéphanie , Thimme Robert , Weidmann Manfred , Casanova Jean-Laurent , Haller Otto , Kochs Georg
Published: May 2007

The human MxA gene belongs to the class of interferon (IFN)-stimulated genes (ISGs) involved in antiviral resistance against influenza viruses. Here, we studied the requirements for MxA induction by influenza A virus infection. MxA is transcriptionally upregulated by type I (alpha and beta) and type III (lambda) IFNs. Therefore, MxA is widely used in gene expression studies as a reliable marker for IFN bioactivity. It is not known, however, whether viruses can directly activate MxA expression in the absence of secreted IFN. By using an NS1-deficient influenza A virus and human cells with defects in IFN production or the STAT1 gene, we studied the induction profile of MxA by real-time reverse transcriptase PCR. The NS1-deficient virus is known to be a strong activator of the IFN system because NS1 acts as a viral IFN-antagonistic protein. Nevertheless, MxA gene expression was not inducible by this virus upon infection of IFN nonproducer cells and STAT1-null cells. Likewise, neither IFN-α nor IFN-λ had a sizeable effect on the STAT1-null cells, indicating that MxA expression requires STAT1 signaling and cannot be triggered directly by virus infection. In contrast, the expression of the IFN-stimulated gene ISG56 was induced by influenza virus in these cells, confirming that ISG56 differs from MxA in being directly inducible by viral triggers in an IFN-independent way. In summary, our study reveals that MxA is a unique marker for the detection of type I and type III IFN activity during virus infections and IFN therapy.
Recognition of a Defined Region within p24 Gag by CD8+T Cells during Primary Human Immunodeficiency Virus Type 1 Infection in Individuals Expressing Protective HLA Class I Alleles
Authors: Streeck Hendrik , Lichterfeld Mathias , Alter Galit , Meier Angela , Teigen Nickolas , Yassine-Diab Bader , Sidhu Harlyn K. , Little Susan , Kelleher Anthony , Routy Jean-Pierre , Rosenberg Eric S. , Sekaly Rafick-Pierre , Walker Bruce D. , Altfeld Marcus
Published: May 2007

Human immunodeficiency virus type 1 (HIV-1)-specific immune responses during primary HIV-1 infection appear to play a critical role in determining the ultimate speed of disease progression, but little is known about the specificity of the initial HIV-1-specific CD8+T-cell responses in individuals expressing protective HLA class I alleles. Here we compared HIV-1-specific T-cell responses between subjects expressing the protective allele HLA-B27 or -B57 and subjects expressing nonprotective HLA alleles using a cohort of over 290 subjects identified during primary HIV-1 infection. CD8+T cells of individuals expressing HLA-B27 or -B57 targeted a defined region within HIV-1 p24 Gag (amino acids 240 to 272) early in infection, and responses against this region contributed over 35% to the total HIV-1-specific T-cell responses in these individuals. In contrast, this region was rarely recognized in individuals expressing HLA-B35, an HLA allele associated with rapid disease progression, or in subjects expressing neither HLA-B57/B27 nor HLA-B35 (P< 0.0001). The identification of this highly conserved region in p24 Gag targeted in primary infection specifically in individuals expressing HLA class I alleles associated with slower HIV-1 disease progression provides a rationale for vaccine design aimed at inducing responses to this region restricted by other, more common HLA class I alleles.
Peptide-Mediated Interference with Influenza A Virus Polymerase
Authors: Ghanem Alexander , Mayer Daniel , Chase Geoffrey , Tegge Werner , Frank Ronald , Kochs Georg , García-Sastre Adolfo , Schwemmle Martin
Published: May 2007

The assembly of the polymerase complex of influenza A virus from the three viral polymerase subunits PB1, PB2, and PA is required for viral RNA synthesis. We show that peptides which specifically bind to the protein-protein interaction domains in the subunits responsible for complex formation interfere with polymerase complex assembly and inhibit viral replication. Specifically, we provide evidence that a 25-amino-acid peptide corresponding to the PA-binding domain of PB1 blocks the polymerase activity of influenza A virus and inhibits viral spread. Targeting polymerase subunit interactions therefore provides a novel strategy to develop antiviral compounds against influenza A virus or other viruses.
Truncated Form of the Epstein-Barr Virus Protein EBNA-LP Protects against Caspase-Dependent Apoptosis by Inhibiting Protein Phosphatase 2A
Authors: Garibal Julie , Hollville Émilie , Bell Andrew I. , Kelly Gemma L. , Renouf Benjamin , Kawaguchi Yasushi , Rickinson Alan B. , Wiels Joëlle
Published: May 2007

The Epstein-Barr virus (EBV)-encoded leader protein, EBNA-LP, strongly activates the EBNA2-mediated transcriptional activation of cellular and viral genes and is therefore important for EBV-induced B-cell transformation. However, a truncated form of EBNA-LP is produced in cells infected with variant EBV strains lacking EBNA2 due to a genetic deletion. The function of this truncated form is unknown. We show here that some Burkitt's lymphoma cells harboring defective EBV strains are specifically resistant to the caspase-dependent apoptosis induced by verotoxin 1 (VT-1) or staurosporine. These cells produced low-molecular-weight Y1Y2-truncated isoforms of EBNA-LP, which were partly localized in the cytoplasm. The transfection of sensitive cells with constructs encoding truncated EBNA-LP isoforms, but not full-length EBNA-LP, induced resistance to caspase-mediated apoptosis. Furthermore, VT-1 induced protein phosphatase 2A (PP2A) activation in sensitive cells but not in resistant cells, in which the truncated EBNA-LP interacted with this protein. Thus, the resistance to apoptosis observed in cells harboring defective EBV strains most probably results from the inactivation of PP2A via interactions with low-molecular-weight Y1Y2-truncated EBNA-LP isoforms.
Function of the Respiratory Syncytial Virus Small Hydrophobic Protein
Authors: Fuentes Sandra , Tran Kim C. , Luthra Priya , Teng Michael N. , He Biao
Published: May 2007

Respiratory syncytial virus (RSV), a member of the
Paramyxoviridae
family, encodes a small hydrophobic (SH) protein of unknown function. Parainfluenza virus 5 (PIV5), a prototypical paramyxovirus, also encodes an SH protein, which inhibits tumor necrosis factor alpha (TNF-α) signaling. In this study, recombinant PIV5 viruses without their own SH but containing RSV SH (from RSV strain A2 or B1) in its place (PIV5ΔSH-RSV SH) and RSV lacking its own SH (RSVΔSH) were generated and analyzed. The results indicate that the SH protein of RSV has a function similar to that of PIV5 SH and that it can inhibit TNF-α signaling.
Small Interfering RNA Profiling Reveals Key Role of Clathrin-Mediated Endocytosis and Early Endosome Formation for Infection by Respiratory Syncytial Virus
Authors: Kolokoltsov Andrey A. , Deniger Drew , Fleming Elisa H. , Roberts Norbert J. , Karpilow Jon M. , Davey Robert A.
Published: May 2007

Respiratory syncytial virus (RSV) is a common cause of respiratory tract infections in infants and the elderly. Like many other pH-independent enveloped viruses, RSV is thought to enter at the cell surface, independently of common endocytic pathways. We have used a targeted small interfering RNA (siRNA) library to identify key cellular genes involved in cytoskeletal dynamics and endosome trafficking that are important for RSV infection. Surprisingly, RSV infection was potently inhibited by siRNAs targeting genes associated with clathrin-mediated endocytosis, including clathrin light chain. The important role of clathrin-mediated endocytosis was confirmed by the expression of well-characterized dominant-negative mutants of genes in this pathway and by using the clathrin endocytosis inhibitor chlorpromazine. We conclude that, while RSV may be competent to enter at the cell surface, clathrin function and endocytosis are a necessary and important part of a productive RSV infection, even though infection is strictly independent of pH. These findings raise the possibility that other pH-independent viruses may share a similar dependence on endocytosis for infection and provide a new potential avenue for treatment of infection.
Molecular Umbrellas: a Novel Class of Candidate Topical Microbicides To Prevent Human Immunodeficiency Virus and Herpes Simplex Virus Infections
Authors: Madan Rebecca Pellett , Mesquita Pedro M. M. , Cheshenko Natalia , Jing Bingwen , Shende Vikas , Guzman Esmeralda , Heald Taylor , Keller Marla J. , Regen Steven L. , Shattock Robin J. , Herold Betsy C.
Published: May 2007

Molecular umbrella compounds may function as novel topical microbicides to prevent human immunodeficiency virus (HIV) and herpes simplex virus (HSV) infections. In a preliminary structure-activity investigation, one umbrella compound, designated Spm8CHAS, was identified which inhibited both HIV and HSV infections with no cellular toxicity. The objectives of the current studies were to define its spectrum of antiviral activity, characterize its mechanism of action, and explore the possibility of combining Spm8CHAS with HIV-specific reverse transcriptase inhibitors. Spm8CHAS inhibited infections by laboratory and clinical R5 and X4 clade B and clade C HIV strains in cell culture. Ectocervical tissue explants exposed to HIV-1
BaL
in the presence of Spm8CHAS were completely protected (50% inhibitory concentration [IC
50
], 13.6 μg/ml), and transfer of virus to target T cells via migratory cells was abolished (IC
50
, 3.8 μg/ml). Spm8CHAS inhibited HSV-2 infection of epithelial cells 10,000-fold if present throughout the infection. Notably, adding Spm8CHAS to cultures following HSV entry significantly reduced viral infection, indicating that the drug also acts postentry. Subsequent studies indicated that Spm8CHAS blocks cell-to-cell spread of HSV. Confocal microscopy using a fluorescently labeled analog of Spm8CHAS demonstrated that this conjugate crosses the plasma cell membrane and is transported to the nucleus. Combinations of Spm8CHAS with UC-781 or 9-[
R
-2-(phosphonylmethoxy)propyl] adenine monohydrate in vitro exhibited additive anti-HIV activity with preserved anti-HSV activity. The abilities of Spm8CHAS to inhibit primary isolates of HIV, block HSV infection postentry, and cross cell membranes support the development of a combination microbicide containing Spm8CHAS with an HIV-specific reverse transcriptase inhibitor to prevent both HIV and HSV infections by multiple mechanisms.
Acetylation and nitrosation of ciprofloxacin by environmental strains of mycobacteria
Authors: Adjei Michael D , Heinze Thomas M , Deck Joanna , Freeman James P , Williams Anna J , Sutherland John B
Published: May 2007

To determine the ability of environmental bacteria to metabolize the frequently prescribed fluoroquinolone drug ciprofloxacin, eight Mycobacterium spp. cultures were grown for 4 days in a medium containing sorbitol and yeast extract with 100 mg·L–1ciprofloxacin. After the cultures had been centrifuged and the supernatants extracted with ethyl acetate, two metabolites were purified by using high-performance liquid chromatography. They were identified with liquid chromatography/electrospray ionization mass spectrometry and proton nuclear magnetic resonance spectroscopy. Ciprofloxacin was transformed to both N-acetylciprofloxacin (2.5%–5.5% of the total peak area at 280 nm) and N-nitrosociprofloxacin (6.0%–8.0% of the peak area) by Mycobacterium gilvum PYR-GCK and Mycobacterium sp. PYR100 but it was transformed only to N-acetylciprofloxacin by Mycobacterium frederiksbergense FAn9, M. gilvum ATCC 43909, M. gilvum BB1, Mycobacterium smegmatis mc2155, Mycobacterium sp. 7E1B1W, and Mycobacterium sp. RJGII-135. The results suggest that biotransformation may serve as a ciprofloxacin resistance mechanism for these bacteria.Key words: acetylation, ciprofloxacin, fluoroquinolones, Mycobacterium, nitrosation.
Angiotensin II inhibits native bTREK-1 K+ channels through a PLC-, kinase C-, and PIP2-independent pathway requiring ATP hydrolysis
Authors: Liu Haiyan , Enyeart Judith A. , Enyeart John J.
Published: May 2007

Angiotensin II (ANG II) inhibits bTREK-1 (bovine KCNK2) K+ channels in bovine adrenocortical cells through a Gq-coupled AT1 receptor by activation of separate Ca2+- and ATP hydrolysis-dependent signaling pathways. Whole cell patch-clamp recording from bovine adrenal zona fasciculata (AZF) cells was used to characterize the ATP-dependent signaling mechanism for inhibition of bTREK-1 by ANG II. We discovered that ATP-dependent inhibition of bTREK-1 by ANG II occurred through a novel mechanism that was independent of PLC and its established downstream effectors. The ATP-dependent inhibition of bTREK-1 by ANG II was not reduced by the PLC antagonists edelfosine and U73122, or by the PKC antagonists bisindolylmaleimide I (BIM) or calphostin C. bTREK-1 was partially inhibited (∼25%) by the PKC activator phorbol 12,13 dibutyrate (PDBu) through an ATP-dependent mechanism that was blocked by BIM. Addition of Phosphatidylinositol( 4 , 5 ) bisphosphate diC8 [DiC8PI( 4 , 5 )P2], a water-soluble derivative of phosphotidyl inositol 4,5 bisphosphate (PIP2) to the pipette solution failed to alter inhibition by ANG II. bTREK-1 inhibition by ANG II was also insensitive to antagonists of other protein kinases activated by ANG II in adrenocortical cells but was completely blocked by inorganic polytriphosphate PPPi. DiC8PI( 4 , 5 )P2 was a weak activator of bTREK-1 channels, compared with the high-affinity ATP analog N6-(2-phenylethyl)adenosine-5′-O-triphosphate (6-PhEt-ATP). These results demonstrate that the modulation of bTREK-1 channels in bovine AZF cells is distinctive with respect to activation by phosphoinositides and nucleotides and inhibition by Gq-coupled receptors. Importantly, ANG II inhibits bTREK-1 channels through a novel pathway that is different from that described for inhibition of native TREK-1 channels in neurons, or cloned channels expressed in cell lines. They also indicate that, under physiological conditions, ANG II inhibits bTREK-1 and depolarizes AZF cells by two, novel, independent pathways that diverge proximal to the activation of PLC.
Endogenous and exogenous cardiac glycosides: their roles in hypertension, salt metabolism, and cell growth
Authors: Schoner Wilhelm , Scheiner-Bobis Georgios
Published: May 2007

Cardiotonic steroids (CTS), long used to treat heart failure, are endogenously produced in mammals. Among them are the hydrophilic cardenolide ouabain and the more hydrophobic cardenolide digoxin, as well as the bufadienolides marinobufagenin and telecinobufagin. The physiological effects of endogenous ouabain on blood pressure and cardiac activity are consistent with the “Na+-lag” hypothesis. This hypothesis assumes that, in cardiac and arterial myocytes, a CTS-induced local increase of Na+ concentration due to inhibition of Na+/K+-ATPase leads to an increase of intracellular Ca2+ concentration ([Ca2+]i) via a backward-running Na+/Ca2+ exchanger. The increase in [Ca2+]i then activates muscle contraction. The Na+-lag hypothesis may best explain short-term and inotropic actions of CTS. Yet all data on the CTS-induced alteration of gene expression are consistent with another hypothesis, based on the Na+/K+-ATPase “signalosome,” that describes the interaction of cardiac glycosides with the Na+ pump as machinery activating various signaling pathways via intramembrane and cytosolic protein-protein interactions. These pathways, which may be activated simultaneously or selectively, elevate [Ca2+]i, activate Src and the ERK1/2 kinase pathways, and activate phosphoinositide 3-kinase and protein kinase B (Akt), NF-κB, and reactive oxygen species. A recent development indicates that new pharmaceuticals with antihypertensive and anticancer activities may be found among CTS and their derivatives: the antihypertensive rostafuroxin suppresses Na+ resorption and the Src-epidermal growth factor receptor-ERK pathway in kidney tubule cells. It may be the parent compound of a new principle of antihypertensive therapy. Bufalin and oleandrin or the cardenolide analog UNBS-1450 block tumor cell proliferation and induce apoptosis at low concentrations in tumors with constitutive activation of NF-κB.
MAPK pathway mediates EGR-1-HSP70-dependent cigarette smoke-induced chemokine production
Authors: Li Chao-Jun , Ning Wen , Matthay Michael A. , Feghali-Bostwick Carol A. , Choi Augustine M. K.
Published: May 2007

Cigarette smoking, a major risk factor for chronic obstructive pulmonary disease, can cause airway inflammation, airway narrowing, and loss of elasticity, leading to chronic airflow limitation. In this report, we sought to define the signaling pathways activated by smoke and to identify molecules responsible for cigarette smoke-induced inflammation. We applied cigarette smoke water extract (CSE) to primary human lung fibroblasts and found that CSE significantly increased CXC chemokine IL-8 production. Meanwhile, 70-kDa heat shock protein (HSP70) was also induced by CSE in a dose- and time-dependent manner. CSE treatment stimulated HSP70 secretion by primary fibroblasts, which augmented IL-8 production. This was further confirmed by exogenously added recombinant HSP70. Using HSP70 small interfering RNA, we confirmed that CSE-induced chemokine production was dependent on heat shock protein expression. Further investigation showed that CSE could also stimulate early growth response-1 (EGR-1) in an ERK-dependent manner and that the expression of HSP70 was EGR-1 dependent. In view of these findings, we hypothesize that the MAPK-EGR-1-HSP70 pathway regulates the cigarette smoke-induced inflammatory process.
Control of breathing and adaptation to high altitude in the bar-headed goose
Authors: Scott Graham R. , Milsom William K.
Published: May 2007

The bar-headed goose flies over the Himalayan mountains on its migratory route between South and Central Asia, reaching altitudes of up to 9,000 m. We compared control of breathing in this species with that of low-altitude waterfowl by exposing birds to step decreases in inspired O2under both poikilocapnic and isocapnic conditions. Bar-headed geese breathed substantially more than both greylag geese and pekin ducks during severe environmental (poikilocapnic) hypoxia (5% inspired O2). This was entirely due to an enhanced tidal volume response to hypoxia, which would have further improved parabronchial (effective) ventilation. Consequently, O2loading into the blood and arterial Po2were substantially improved. Because air convection requirements were similar between species at 5% inspired O2, it was the enhanced tidal volume response (not total ventilation per se) that improved O2loading in bar-headed geese. Other observations suggest that bar-headed geese depress metabolism less than low-altitude birds during hypoxia and also may be capable of generating higher inspiratory airflows. There were no differences between species in ventilatory sensitivities to isocapnic hypoxia, the hypoxia-induced changes in blood CO2tensions or pH, or hypercapnic ventilatory sensitivities. Overall, our results suggest that evolutionary changes in the respiratory control system of bar-headed geese enhance O2loading into the blood and may contribute to this species' exceptional ability to fly high.
Characterization of the febrile response induced by fibroblast-stimulating lipopeptide-1 in guinea pigs
Authors: Greis Andrea , Murgott Jolanta , Rafalzik Sandra , Gerstberger Rüdiger , Hübschle Thomas , Roth Joachim
Published: May 2007

Recently, it has been shown that the Toll-like receptors-2 and -6 agonist fibroblast-stimulating lipopeptide-1 (FSL-1) have the capacity to induce fever and sickness behavior in rats. Since the mechanisms of the fever-inducing effects of FSL-1 are still unknown, we tested the pyrogenic properties of FSL-1 in guinea pigs and assessed a role for TNF-α and prostaglandins in the manifestation of the febrile response to this substance. Intra-arterial and intraperitoneal injections of FSL-1 caused dose-dependent fevers that coincided with elevated plasma levels of TNF and IL-6, the intraperitoneal route of administration being more effective than the intra-arterial route. Intra-arterial or intraperitoneal injection of a soluble form of the TNF type 1 receptor, referred to as TNF binding protein (TNFbp), together with FSL-1, completely neutralized FSL-1-induced circulating TNF and reduced fever and circulating IL-6. Intra-arterial or intraperitoneal injection of the nonselective cyclooxygenase (COX)-inhibitor diclofenac depressed fever and FSL-1-induced elevations of circulating PGE2. Circulating TNF and IL-6, however, remained unimpaired by treatment with diclofenac. In conclusion, FSL-1-induced fever in guinea pigs depends, in shape and duration, on the route of administration and is, to a high degree, mediated by pyrogenic cytokines and COX products.
Regulation of calcium balance in the sturgeonAcipenser naccarii: a role for PTHrP
Authors: Fuentes Juan , Haond Christophe , Guerreiro Pedro M. , Silva Nádia , Power Deborah M. , Canário Adelino V. M.
Published: May 2007

Calcium regulation in sturgeon is of special interest because they are a representative of the ancient fishes possessing mainly cartilaginous skeletons and a supposedly low calcium demand. The present study aimed to characterize the effect of a chronic absence of dietary calcium and the effect of parathyroid hormone-related protein (PTHrPA) (1-34) ( 7 ) on calcium balance in juvenile sturgeon ( Acipenser naccarii). At rest, sturgeon juveniles are in net positive calcium balance, since whole body calcium uptake is significantly higher than efflux and calcium accumulates in the body. To study the importance of dietary calcium, the sturgeon were kept on a calcium-free diet for 8 wk. This manipulation impaired growth as measured by failure to gain weight or increase in length and indicates that dietary calcium is important for growth in sturgeon. An increased whole body calcium uptake partially compensated dietary calcium deficiency and was associated with increased gill chloride cell number in lamellae and filaments in parallel with increased gill Na+K+-ATPase activity. In addition, a single injection of piscine PTHrP(1-34) significantly increased whole body calcium uptake and decreased whole body calcium efflux. Administration of PTHrP significantly increased circulating plasma calcium 4–24 h postinjection. The increase in net calcium transport and increased plasma levels of calcium is consistent with the actions of a hypercalcemic factor. It would appear that the sturgeon rely on calcium for growth and tightly regulate calcium transport. The action in calcium balance is consistent with PTHrP acting as a hypercalcemic factor in sturgeon.
Vasodilatation of afferent arterioles and paradoxical increase of renal vascular resistance by furosemide in mice
Authors: Oppermann Mona , Hansen Pernille B. , Castrop Hayo , Schnermann Jurgen
Published: May 2007

Loop diuretics like furosemide have been shown to cause renal vasodilatation in dogs and humans, an effect thought to result from both a direct vascular dilator effect and from inhibition of tubuloglomerular feedback. In isolated perfused afferent arterioles preconstricted with angiotensin II or NG-nitro-l-arginine methyl ester, furosemide caused a dose-dependent increase of vascular diameter, but it was without effect in vessels from NKCC1−/− mice suggesting that inhibition of NKCC1 mediates dilatation in afferent arterioles. In the intact kidney, however, furosemide (2 mg/kg iv) caused a 50.5 ± 3% reduction of total renal blood flow (RBF) and a 27% reduction of superficial blood flow (SBF) accompanied by a marked and immediate increase of tubular pressure and volume. At 10 mg/kg, furosemide reduced RBF by 60.4 ± 2%. Similarly, NKCC1−/− mice responded to furosemide with a 45.4% decrease of RBF and a 29% decrease of SBF. Decreases in RBF and SBF and increases of tubular pressure by furosemide were ameliorated by renal decapsulation. In addition, pretreatment with candesartan (2 mg/kg) or indomethacin (5 mg/kg) attenuated the reduction of RBF and peak urine flows caused by furosemide. Our data indicate that furosemide, despite its direct vasodilator potential in isolated afferent arterioles, causes a marked increase in flow resistance of the vascular bed of the intact mouse kidney. We suggest that generation of angiotensin II and/or a vasoconstrictor prostaglandin combined with compression of peritubular capillaries by the expanding tubular compartment are responsible for the reduction of RBF in vivo.
Microcirculation: nexus of comorbidities in diabetes
Authors: Temm Constance , Dominguez Jesus H.
Published: May 2007

Generalized capillary dysfunction is a morbid element in the metabolic syndrome, and it is likely involved in its complications. We tested the hypothesis that vast amounts of serum albumin previously observed in kidneys of rats with the metabolic syndrome were caused, in part, by leakage from renal peritubular capillaries. We report herein large scale leaks of plasma fluid in peritubular capillaries of rats with the metabolic syndrome. This finding was directly demonstrated in vivo, and the presence of leftover albumin residue confirmed the leak in postmortem kidney specimens. Moreover, renal interstitial fibrosis and tubular atrophy were found in a distribution similar to the leaked renal albumin in obese rats. We suggest that there is an important link between peritubular capillary damage and interstitial fibrosis, represented as tubulointerstitial disease in the metabolic syndrome. We propose that maintenance of the peritubular microcirculation may improve renal outcomes in diabetes and the metabolic syndrome.
Estimating changes in mean body temperature for humans during exercise using core and skin temperatures is inaccurate even with a correction factor
Authors: Jay Ollie , Reardon Francis D. , Webb Paul , DuCharme Michel B. , Ramsay Tim , Nettlefold Lindsay , Kenny Glen P.
Published: May 2007

Changes in mean body temperature (ΔT̄b) estimated by the traditional two-compartment model of “core” and “shell” temperatures and an adjusted two-compartment model incorporating a correction factor were compared with values derived by whole body calorimetry. Sixty participants (31 men, 29 women) cycled at 40% of peak O2 consumption for 60 or 90 min in the Snellen calorimeter at 24 or 30°C. The core compartment was represented by esophageal, rectal (Tre), and aural canal temperature, and the shell compartment was represented by a 12-point mean skin temperature (T̄sk). Using Tre and conventional core-to-shell weightings ( X) of 0.66, 0.79, and 0.90, mean ΔT̄b estimation error (with 95% confidence interval limits in parentheses) for the traditional model was −95.2% (−83.0, −107.3) to −76.6% (−72.8, −80.5) after 10 min and −47.2% (−40.9, −53.5) to −22.6% (−14.5, −30.7) after 90 min. Using Tre, X = 0.80, and a correction factor ( X0) of 0.40, mean ΔT̄b estimation error for the adjusted model was +9.5% (+16.9, +2.1) to −0.3% (+11.9, −12.5) after 10 min and +15.0% (+27.2, +2.8) to −13.7% (−4.2, −23.3) after 90 min. Quadratic analyses of calorimetry ΔT̄b data was subsequently used to derive best-fitting values of X for both models and X0 for the adjusted model for each measure of core temperature. The most accurate model at any time point or condition only accounted for 20% of the variation observed in ΔT̄b for the traditional model and 56% for the adjusted model. In conclusion, throughout exercise the estimation of ΔT̄b using any measure of core temperature together with mean skin temperature irrespective of weighting is inaccurate even with a correction factor customized for the specific conditions.
Dissociation of Eye and Head Components of Gaze Shifts by Stimulation of the Omnipause Neuron Region
Authors: Gandhi Neeraj J. , Sparks David L.
Published: May 2007

Natural movements often include actions integrated across multiple effectors. Coordinated eye-head movements are driven by a command to shift the line of sight by a desired displacement vector. Yet because extraocular and neck motoneurons are separate entities, the gaze shift command must be separated into independent signals for eye and head movement control. We report that this separation occurs, at least partially, at or before the level of pontine omnipause neurons (OPNs). Stimulation of the OPNs prior to and during gaze shifts temporally decoupled the eye and head components by inhibiting gaze and eye saccades. In contrast, head movements were consistently initiated before gaze onset, and ongoing head movements continued along their trajectories, albeit with some characteristic modulations. After stimulation offset, a gaze shift composed of an eye saccade, and a reaccelerated head movement was produced to preserve gaze accuracy. We conclude that signals subject to OPN inhibition produce the eye-movement component of a coordinated eye-head gaze shift and are not the only signals involved in the generation of the head component of the gaze shift.