bluuebunny/crossref_metadata_2025 huggingface dataset:
Feasibility of a Multiplex Flow Cytometric Bead Immunoassay for Detection of Anti-Epoetin Alfa Antibodies
Authors: Ferbas John , Thomas John , Hodgson John , Gaur Amitabh , Casadevall Nicole , Swanson Steven J.
Published: July 2007

Immunogenicity profiles of recombinant therapeutic proteins are important to understand because antibodies raised against these molecules may have important clinical sequelae. The purpose of the present study was to demonstrate that a flow cytometric bead array could be used to detect clinically relevant antibodies with specificity to such therapeutics. We chose to evaluate well-characterized specimens from persons treated with epoetin alfa that developed antibody-mediated pure red blood cell aplasia as a means to demonstrate the utility of this platform. Our data show that this assay is capable of detecting anti-epoetin alfa antibodies with a relative antibody concentration of 50 ng/ml, where 25 of 25 sera spiked with antibodies at this concentration scored positive. Moreover, the assay was designed to include positive and negative control beads for each specimen that is processed to ensure the specificity of the signal when detected. Measurement of interassay precision supports quantitative estimates of relative antibody concentrations in the range of 313 to 5,000 ng/ml, where the percent coefficient of variation did not exceed 20%. With respect to clinical specimens, antibodies with specificity for epoetin alfa could be easily detected in a set of specimens from persons with pure red blood cell aplasia that had prior exposure to the EPREX brand of recombinant epoetin alfa. Further development and validation of this approach may facilitate successful widespread application of the method for detection of anti-epoetin alfa antibodies, as well as antibodies directed against other recombinant therapeutic proteins.
Extracellular ATP Is Cytotoxic to Mononuclear Phagocytes but Does Not Induce Killing of IntracellularMycobacterium aviumsubsp.paratuberculosis
Authors: Woo Seng-Ryong , Barletta Raúl G. , Czuprynski Charles J.
Published: July 2007

Mycobacterium aviumsubsp.paratuberculosisis the etiologic agent of Johne's disease, a chronic granulomatous enteritis in ruminants. ATP has been reported to induce cell death of macrophages and killing ofMycobacteriumspecies in human and murine macrophages. In this study we investigated the short-term effect of ATP on the viability ofM. aviumsubsp.paratuberculosis-infected bovine mononuclear phagocytes and the bacilli within them. Addition of 5 mM ATP toM. aviumsubsp.paratuberculosis-infected bovine monocytes resulted in 50% cytotoxicity of bovine monocytes at 24 h. Addition of 2′(3′)-O-(4-benzoylbenzoyl) ATP triethylammonium salt (Bz-ATP), which is a longer-lived ATP homologue and purinergic receptor agonist, significantly increased the uptake of YO-PRO, which is a marker for membrane pore activation by P2X receptors. Addition of Bz-ATP also stimulated lactate dehydrogenase release and caspase-3 activity in infected bovine monocytes. Neither ATP nor Bz-ATP reduced the survival ofM. aviumsubsp.paratuberculosisin bovine mononuclear phagocytes. Likewise, addition of ATP or Bz-ATP was cytotoxic to murine macrophage cell lines (RAW 264.7 and J774A.1 cells) but did not affect the intracellular survival ofM. aviumsubsp.paratuberculosis, nor were the numbers of viableMycobacterium aviumsubsp.aviumorMycobacterium bovisBCG cells altered in bovine mononuclear phagocytes or J774A.1 cells following ATP or Bz-ATP treatment. These data suggest that extracellular ATP does not induce the killing of intracellularM. aviumsubsp.paratuberculosisin bovine mononuclear phagocytes.
Measurement of Staphylococcal Enterotoxin B in Serum and Culture Supernatant with a Capture Enzyme-Linked Immunosorbent Assay
Authors: Cook E. , Wang X. , Robiou N. , Fries B. C.
Published: July 2007

Staphylococcal enterotoxin B (SEB) is a select agent because it is a potent mitogen that elicits life-threatening polyclonal T-cell proliferation and cytokine production at very low concentrations. Efforts are in progress to develop therapeutic reagents and vaccines that neutralize or prevent the devastating effects of this toxin. Because of its rapid binding to in vivo receptors, this toxin is difficult to detect in serum. This rapid binding also constitutes a major challenge for the development of effective therapeutic reagents that can neutralize the effects of the toxin in vivo. We have developed a highly sensitive capture enzyme-linked immunosorbent assay that detects SEB in body fluids at very low levels. With this assay, the peak levels of SEB in serum and renal clearance can be measured in mice. After either oral ingestion or nasal inhalation of SEB by mice, this assay documents the transcytosis of SEB across the mucosal membranes into serum within 2 h. Furthermore, this assay was used to compare the SEB levels in different murine models for SEB-induced lethal shock and demonstrated that the coadministration of toxin-enhancing chemicals, such as
d
-galactosamine and lipopolysaccharide, can alter the peak serum SEB levels. Hence, this assay is a potentially useful tool for the study of the pharmacokinetics of SEB and the effects of potential therapeutic reagents on serum SEB levels.
Molecular Diagnosis of
Kingella kingae
Pericarditis by Amplification and Sequencing of the 16S rRNA Gene
Authors: Matta Matta , Wermert Delphine , Podglajen Isabelle , Sanchez Olivier , Buu-Hoï Annie , Gutmann Laurent , Meyer Guy , Mainardi Jean-Luc
Published: July 2007

Kingella kingae
is a fastidious gram-negative bacillus that is considered an emerging pathogen in pediatric settings but remains less common in adults. Here we describe a case of pericarditis in an immunocompetent adult host. The microorganism was identified directly from the clinical sample by molecular techniques, i.e., 16S rRNA gene amplification and sequencing.
Molecular Epidemiology and Distribution of Serotypes, Surface Proteins, and Antibiotic Resistance among Group B Streptococci in Italy
Authors: Gherardi Giovanni , Imperi Monica , Baldassarri Lucilla , Pataracchia Marco , Alfarone Giovanna , Recchia Simona , Orefici Graziella , Dicuonzo Giordano , Creti Roberta
Published: July 2007

Group B streptococci (GBS) comprising three different sets of isolates (31 invasive, 36 noninvasive, and 24 colonizing isolates) were collected in Italy during the years 2002 to 2005. Clonal groups were established by pulsed-field gel electrophoresis (PFGE), and selected isolates were studied by multilocus sequence typing (MLST). GBS isolates were also characterized by classical and molecular techniques for serotyping and protein gene and antibiotic resistance profiling. Some serotypes were significantly associated with a particular isolate population: serotype Ia more frequently corresponded to invasive strains than other strains, serotype V was more frequently encountered among noninvasive strains, and nontypeable strains were more common among isolates from carriers. Four major clonal groups accounted for 52.7% of all isolates: PFGE type 1/clonal complex 1 (CC1) comprised mainly serotype V isolates carrying the
alp3
gene, PFGE type 2/CC23 encompassed serotype Ia isolates with the
alp1
or
alpha
gene, PFGE type 3/CC17 comprised serotype III isolates carrying the
rib
gene, and PFGE type 4/CC19 consisted mainly of serotype II isolates possessing the
rib
gene. The same serotypes were shared by isolates of different clonal groups, and conversely, isolates belonging to the same clonal groups were found to be of different serotypes, presumably due to capsular switching by the horizontal transfer of capsular genes. Erythromycin resistance (prevalence, 16.5%; 15 resistant isolates of 91) was restricted to strains isolated from patients with noninvasive infections and carriers, while tetracycline resistance was evenly distributed (prevalence, 68.1%; 62 resistant isolates of 91). Most erythromycin-resistant GBS strains were of serotype V, were
erm
(B) positive, and belonged to the PFGE type 1/CC1 group, suggesting that macrolide resistance may have arisen both by clonal dissemination and by the horizontal transfer of resistance genes.
Human Cytomegalovirus Protein Kinase UL97 Forms a Complex with the Tegument Phosphoprotein pp65
Authors: Kamil Jeremy P. , Coen Donald M.
Published: July 2007

UL97 is a protein kinase encoded by human cytomegalovirus (HCMV) and is an important target for antiviral drugs against this ubiquitous herpesvirus, which is a major cause of life-threatening opportunistic infections in the immunocompromised host. In an effort to better understand the function(s) of UL97 during HCMV replication, a recombinant HCMV, NTAP97, which expresses a tandem affinity purification (TAP) tag at the amino terminus of UL97, was used to obtain UL97 protein complexes from infected cells. pp65 (also known as UL83), the 65-kDa virion tegument phosphoprotein, specifically copurified with UL97 during TAP, as shown by mass spectrometry and Western blot analyses. Reciprocal coimmunoprecipitation experiments using lysates of infected cells also indicated an interaction between UL97 and pp65. Moreover, in a glutathioneS-transferase (GST) pull-down experiment, purified GST-pp65 fusion protein specifically bound in vitro-translated UL97, suggesting that UL97 and pp65 do not require other viral proteins to form a complex and may directly interact. Notably, pp65 has been previously reported to form unusual aggregates during viral replication when UL97 is pharmacologically inhibited or genetically ablated, and a pp65 deletion mutant was observed to exhibit modest resistance to a UL97 inhibitor (M. N. Prichard, W. J. Britt, S. L. Daily, C. B. Hartline, and E. R. Kern, J. Virol. 79:15494-15502, 2005). A stable protein-protein interaction between pp65 and UL97 may be relevant to incorporation of these proteins into HCMV particles during virion morphogenesis, with potential implications for immunomodulation by HCMV, and may also be a mechanism by which UL97 is negatively regulated during HCMV replication.
Alanine Scanning of the Hepatitis C Virus Core Protein Reveals Numerous Residues Essential for Production of Infectious Virus
Authors: Murray Catherine L. , Jones Christopher T. , Tassello Jodie , Rice Charles M.
Published: July 2007

Hepatitis C virus
(HCV) is an important human pathogen affecting an estimated 3% of the world's population. Recent advances have enabled in vitro propagation of the virus and allow assembly and egress to be investigated for the first time. As a component of the virion, the HCV core protein likely functions primarily in infectious virus production, although little is known about the determinants of this activity. To investigate the roles of core in the viral life cycle, we performed a comprehensive deletion and alanine scanning mutagenesis study of this protein in the context of a genotype 2a reporter virus. We have confirmed that core protein is essential for infectious virion production and have identified numerous residues required for this role. The infectivity of several assembly-defective core mutants could be rescued by compensatory mutations identified in p7 and NS2, suggesting genetic interactions with core and highlighting the importance of these nonstructural proteins in infectious virion morphogenesis.
Unequal Evolutionary Rates in the Human Immunodeficiency Virus Type 1 (HIV-1) Pandemic: the Evolutionary Rate of HIV-1 Slows Down When the Epidemic Rate Increases
Authors: Berry Irina Maljkovic , Ribeiro Ruy , Kothari Moulik , Athreya Gayathri , Daniels Marcus , Lee Ha Youn , Bruno William , Leitner Thomas
Published: July 2007

HIV-1 sequences in intravenous drug user (IDU) networks are highly homogenous even after several years, while this is not observed in most sexual epidemics. To address this disparity, we examined the human immunodeficiency virus type 1 (HIV-1) evolutionary rate on the population level for IDU and heterosexual transmissions. All available HIV-1
env
V3 sequences from IDU outbreaks and heterosexual epidemics with known sampling dates were collected from the Los Alamos HIV sequence database. Evolutionary rates were calculated using phylogenetic trees with a
t
test root optimization of dated samples. The evolutionary rate of HIV-1 subtype A1 was found to be 8.4 times lower in fast spread among IDUs in the former Soviet Union (FSU) than in slow spread among heterosexual individuals in Africa. Mixed epidemics (IDU and heterosexual) showed intermediate evolutionary rates, indicating a combination of fast- and slow-spread patterns. Hence, if transmissions occur repeatedly during the initial stage of host infection, before selective pressures of the immune system have much impact, the rate of HIV-1 evolution on the population level will decrease. Conversely, in slow spread, where HIV-1 evolves under the pressure of the immune system before a donor infects a recipient, the virus evolution at the population level will increase. Epidemiological modeling confirmed that the evolutionary rate of HIV-1 depends on the rate of spread and predicted that the HIV-1 evolutionary rate in a fast-spreading epidemic, e.g., for IDUs in the FSU, will increase as the population becomes saturated with infections and the virus starts to spread to other risk groups.
Role of Env in Resistance of Feline Immunodeficiency Virus (FIV)-Infected Cats to Superinfection by a Second FIV Strain as Determined by Using a Chimeric Virus
Authors: Giannecchini Simone , Pistello Mauro , Isola Patrizia , Matteucci Donatella , Mazzetti Paola , Freer Giulia , Bendinelli Mauro
Published: July 2007

A more or less pronounced resistance to superinfection by a second strain of the infecting virus has been observed in many lentivirus-infected hosts. We used a chimeric feline immunodeficiency virus (FIV), designated FIV
χ
, containing a large part of the
env
gene of a clade B virus (strain M2) and all the rest of the genome of a clade A virus (a p34TF10 molecular clone of the Petaluma strain modified to grow in lymphoid cells), to gain insights into such resistance. FIV
χ
was infectious and moderately pathogenic for cats and in vitro exhibited the neutralization specificity of the
env
donor. The experiments performed were bidirectional, in that cats preinfected with either parental virus were challenged with FIV
χ
and vice versa. The preinfected animals were partially or completely protected relative to what was observed in naïve control animals, most likely due, at least in part, to the circumstance that in all the preinfecting/challenge virus combinations examined, the first and the second virus shared significant viral components. Based on the proportions of complete protection observed, the role of a strongly matched viral envelope appeared to be modest and possibly dependent on the time interval between the first and the second infection. Furthermore, complete protection and the presence of measurable neutralizing antibodies capable of blocking the second virus in vitro were not associated.
N-Linked Glycan Modifications in gp120 of Human Immunodeficiency Virus Type 1 Subtype C Render Partial Sensitivity to 2G12 Antibody Neutralization
Authors: Gray Elin S. , Moore Penny L. , Pantophlet Ralph A. , Morris Lynn
Published: July 2007

The monoclonal antibody (MAb) 2G12 recognizes a cluster of high-mannose oligosaccharides on the human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein gp120 and is one of a select group of MAbs with broad neutralizing activity. However, subtype C viruses are generally resistant to 2G12 neutralization. This has been attributed to the absence of a glycosylation site at position 295 in most subtype C gp120s, which instead is typically occupied by a Val residue. Here we show that N-linked glycans in addition to the one at position 295 are important in the formation of the 2G12 epitope in subtype C gp120. Introduction of the glycosylation site at position 295 into three subtype C molecular clones, Du151.2, COT9.6, and COT6.15, did increase 2G12 binding to all three mutagenized gp120s, but at various levels. The COT9-V295N mutant showed the strongest 2G12 binding and was the only mutant to become sensitive to 2G12 neutralization, although very high antibody concentrations were required. Introduction of a glycosylation site at position 448 into mutant COT6-V295N, which occurs naturally in COT9, resulted in a virus that was partially sensitive to 2G12. Interestingly, a glycosylation site at position 442, which is common among subtype C viruses, also contributed to the 2G12 epitope. The addition of this glycan increased virus neutralization sensitivity to 2G12, whereas its deletion conferred resistance. Collectively, our results indicate that the 2G12 binding site cannot readily be reconstituted on the envelopes of subtype C viruses, suggesting structural differences from other HIV subtypes in which the 2G12 epitope is naturally expressed.
Specific Residues of the Influenza A Virus Hemagglutinin Viral RNA Are Important for Efficient Packaging into Budding Virions
Authors: Marsh Glenn A. , Hatami Raheleh , Palese Peter
Published: July 2007

A final step in the influenza virus replication cycle is the assembly of the viral structural proteins and the packaging of the eight segments of viral RNA (vRNA) into a fully infectious virion. The process by which the RNA genome is packaged efficiently remains poorly understood. In an approach to analyze how vRNA is packaged, we rescued a seven-segmented virus lacking the hemagglutinin (HA) vRNA (deltaHA virus). This virus could be passaged in cells constitutively expressing HA protein, but it was attenuated in comparison to wild-type A/WSN/33 virus. Supplementing the deltaHA virus with an artificial segment containing green fluorescent protein (GFP) or red fluorescent protein (RFP) with HA packaging regions (45 3′ and 80 5′ nucleotides) partially restored the growth of this virus to wild-type levels. The absence of the HA vRNA in the deltaHA virus resulted in a 40 to 60% reduction in the packaging of the PA, NP, NA, M, and NS vRNAs, as measured by quantitative PCR (qPCR), and the packaging of these vRNAs was partially restored in the presence of GFP/RFP packaging constructs. To further define nucleotides of the HA coding sequence which are important for vRNA packaging, synonymous mutations were introduced into the full-length HA cDNA of influenza A/WSN/33 and A/Puerto Rico/8/34 viruses, and mutant viruses were rescued. qPCR analysis of vRNAs packaged in these mutant viruses identified a key region of the open reading frame (nucleotides 1659 to 1671) that is critical for the efficient packaging of an influenza virus H1 HA segment.
d-Serine inhibits AMPA receptor-mediated current in rat hippocampal neurons
Authors: Gong Xiang-Qun , Zabek Rebecca L. , Bai Donglin
Published: July 2007

d-Serine, a recently identified gliotransmitter, serves as an endogenous coagonist binding to the glycine site of N-methyl-d-aspartate (NMDA) receptors. However, it is not clear whether this native ligand is able to bind to and modulate α-amino-3-hydroxyl-5-methyl-4-isoxazolepropionate (AMPA) receptors. In the present study, we showed that d-serine was able to concentration-dependently inhibit kainate-induced AMPA receptor-mediated current in acutely isolated hippocampal neurons. The blocking action of d-serine on AMPA receptors was characterized by a shift in concentration–response curve of kainate-induced current to the right with no change in the maximal response and independent of holding potential in the range of –80 to +60 mV. This is consistent with a model that d-serine is a competitive antagonist on AMPA receptors. In contrast, l-serine did not exert such an inhibitory action. Consistent with this observation, we found that several d-isoforms, but not l-isoforms, of endogenous and exogenous amino acids were able to block AMPA receptors. These results indicate that there is a low affinity and stereo-selective site at the agonist binding pocket of AMPA receptors for these d-amino acids. More importantly, vesicular-released endogenous d-serine from astrocytes could potentially modulate AMPA receptors in synaptic transmission in hippocampus.
NONCOMMUTATIVE KdV HIERARCHY
Authors: TREVES FRANÇOIS
Published: July 2007

The noncommutative version of the Korteweg–de Vries equation studied here is shown to admit infinitely many constants of motion and to give rise to a hierarchy of higher-order Hamiltonian evolution equations, each one the noncommutative version of the commutative KdV equation of the same order. The noncommutative KdV polynomials span, topologically, a maximal Abelian subalgebra of the Lie algebra of noncommutative Bäcklund transformations. Two classes of examples of "completely integrable" systems of evolution equations to which the theory applies are described in the last two sections.
CONTINUITY OF THE FOUR-POINT FUNCTION OF MASSIVE $\varphi_{4}^{4}$-THEORY ABOVE THRESHOLD
Authors: KOPPER CHRISTOPH
Published: July 2007

In this paper we prove that the four-point function of massive [Formula: see text]-theory is continuous as a function of its independent external momenta when posing the renormalization condition for the (physical) mass on-shell. The proof is based on integral representations derived inductively from the perturbative flow equations of the renormalization group. It closes a longstanding loophole in rigorous renormalization theory in so far as it shows the feasibility of a physical definition of the renormalized coupling.
NUMERICAL STUDY OF 2D MULTIPHASE FLOWS OVER GROOVED SURFACE BY LATTICE BOLTZMANN METHOD
Authors: HUANG J. J. , SHU C. , CHEW Y. T. , ZHENG H. W.
Published: July 2007

In this paper, the effects of surface wettability and topography on a droplet, which is driven by a body force to pass through grooved walls, are studied by using the multiphase lattice Boltzmann model. At small scale, the shape and velocity of the droplet were found to be strongly affected by the wettability and configuration of the wall. The drag on the droplet moving over grooved surfaces was found to decrease as the wall hydrophobicity increases. It was also found that the wettability decides whether the droplet fills or does not fill the whole grooves.
LATTICE BOLTZMANN SIMULATION ON FLOW WITH SOOT ACCUMULATION IN DIESEL PARTICULATE FILTER
Authors: YAMAMOTO KAZUHIRO , SATAKE SHINGO , YAMASHITA HIROSHI , TAKADA NAOKI , MISAWA MASAKI
Published: July 2007

Since diesel exhaust gas has more ambient air pollutants such as NOx and particulate matters (PM) including soot, the special treatment for exhaust emission standards is needed. Recently, a diesel particulate filter (DPF) has been developed to reduce PM in the after-treatment of exhaust gas. However, since the structure of the filter is small and complex, it is impossible to examine the phenomena inside the filter experimentally. In this study, we conduct fluid simulation in the diesel filter. We use the lattice Boltzmann method. The soot accumulation is considered to simulate the PM trap in the filter. For the wall-boundary in the simulation, the inner structure of the filter is obtained by a 3D-CT technique. Results show complex flow pattern in the diesel filter. Due to the soot accumulation, the velocity is changed and the pressure is increased. The pressure drop becomes larger as soot concentration at the inlet is higher.
HYDRODYNAMIC PROPERTIES AND PERMEABILITY OF FRACTAL OBJECTS
Authors: NGUYEN H. , CHOPARD B. , STOLL S.
Published: July 2007

Using Lattice Boltzmann numerical simulations, we analyse the hydrodynamic properties of both fractal aggregates and artificial fractal objects. First we show that the hydrodynamic radius actually depends on three quantities: the fractal dimension, the so-called prefactor and the inside connectivity. Second, from the simulated velocity field inside the aggregate, we observe that Darcy's law describes the flow better than Brinkman equation. Finally we measure the permeability - porosity relation and observed that it departs from the prediction of Happel's model.
LOCATION, CORRELATION, RADIATION: WHERE IS THE σ, WHAT IS ITS STRUCTURE, AND WHAT IS ITS COUPLING TO PHOTONS?
Authors: PENNINGTON M. R.
Published: July 2007

Scalar mesons are a key expression of the infrared regime of QCD. The lightest of these is the σ. Now that its pole in the complex energy plane has been precisely located, we can ask whether this state is transiently [Formula: see text] or [Formula: see text] or a multi-meson molecule or largely glue? The two-photon decay of the σ can, in principle, discriminate between these possibilities. We review here how the γγ → π+π-, π0π0 cross-sections can be accurately computed. The result not only agrees with experiment, but definitively fixes the radiative coupling of the σ. This equates to a two-photon width of (4.1 ± 0.3) keV, which accords with the simple nonrelativistic quark model expectation for a [Formula: see text], [Formula: see text] scalar. Nevertheless, robust predictions from relativistic strong coupling QCD are required for each of the possible compositions before we can be sure which one really delivers the determined γγ coupling.
TOPOLOGICALLY MASSIVE GAUGE THEORY: A LORENTZIAN SOLUTION
Authors: SAYGILI K.
Published: July 2007

We obtain a Lorentzian solution for the topologically massive non-Abelian gauge theory on AdS space [Formula: see text] by means of an SU (1, 1) gauge transformation of the previously found Abelian solution. There exists a natural scale of length which is determined by the inverse topological mass ν ~ ng2. In the topologically massive electrodynamics the field strength locally determines the gauge potential up to a closed 1-form via the (anti-)self-duality equation. We introduce a transformation of the gauge potential using the dual field strength which can be identified with an Abelian gauge transformation. Then we present map [Formula: see text] including the topological mass which is the Lorentzian analog of the Hopf map. This map yields a global decomposition of [Formula: see text] as a trivial [Formula: see text] bundle over the upper portion of the pseudosphere [Formula: see text] which is the Hyperboloid model for the Lobachevski geometry. This leads to a reduction of the Abelian field equation onto [Formula: see text] using a global section of the solution on [Formula: see text]. Then we discuss the integration of the field equation using the Archimedes map [Formula: see text]. We also present a brief discussion of the holonomy of the gauge potential and the dual field strength on [Formula: see text].
DIRAC NEUTRINO MASSES AND MIXING PARAMETERS IN A LEFT–RIGHT MODEL WITH MIRROR FERMIONS
Authors: GAITÁN R. , HERNÁNDEZ-GALEANA A. , RIVERA-REBOLLEDO J. M. , FERNÁNDEZ DE CÓRDOBA P. , RODRIGUEZ-ROMO S.
Published: July 2007

In this work we consider a left–right model containing mirror fermions with gauge group SU (3)C ⊗ SU (2)L ⊗ SU (2)R ⊗ U (1)Y′. The model has several free parameters which here we have calculated by using the recent values for the squared-neutrino mass differences. Lower bound for the mirror vacuum expectation value helped us to obtain crude estimations for some of these parameters. Also we estimate the order of magnitude of the masses of the standard and mirror neutrinos and numerical values for neutrino mixing angles.
WHY CMB PHYSICS?
Authors: GIOVANNINI MASSIMO
Published: July 2007

The aim of the lectures in this paper is to introduce some basic problems arising in gravitation and modern cosmology. All along the discussion the guiding theme is provided by the phenomenological and theoretical properties of the Cosmic Microwave Background (CMB). These lectures have been prepared for a regular PhD course of the University of Milan-Bicocca.
The α2-adrenergic receptor agonist UK 14,304 inhibits secretin-stimulated ductal secretion by downregulation of the cAMP system in bile duct-ligated rats
Authors: Francis Heather , LeSage Gene , DeMorrow Sharon , Alvaro Domenico , Ueno Yoshiyuki , Venter Julie , Glaser Shannon , Mancino Maria Grazia , Marucci Luca , Benedetti Antonio , Alpini Gianfranco
Published: July 2007

Secretin stimulates ductal secretion by activation of cAMP → PKA → CFTR → Cl−/HCO3− exchanger in cholangiocytes. We evaluated the expression of α2A-, α2B-, and α2C-adrenergic receptors in cholangiocytes and the effects of the selective α2-adrenergic agonist UK 14,304, on basal and secretin-stimulated ductal secretion. In normal rats, we evaluated the effect of UK 14,304 on bile and bicarbonate secretion. In bile duct-ligated (BDL) rats, we evaluated the effect of UK 14,304 on basal and secretin-stimulated 1) bile and bicarbonate secretion; 2) duct secretion in intrahepatic bile duct units (IBDU) in the absence or presence of 5-( N-ethyl- N-isopropyl)amiloride (EIPA), an inhibitor of the Na+/H+ exchanger isoform NHE3; and 3) cAMP levels, PKA activity, Cl− efflux, and Cl−/HCO3− exchanger activity in purified cholangiocytes. α2-Adrenergic receptors were expressed by all cholangiocytes in normal and BDL liver sections. UK 14,304 did not change bile and bicarbonate secretion of normal rats. In BDL rats, UK 14,304 inhibited secretin-stimulated 1) bile and bicarbonate secretion, 2) expansion of IBDU luminal spaces, and 3) cAMP levels, PKA activity, Cl− efflux, and Cl−/HCO3− exchanger activity in cholangiocytes. There was decreased lumen size after removal of secretin in IBDU pretreated with UK 14,304. In IBDU pretreated with EIPA, there was no significant decrease in luminal space after removal of secretin in either the absence or presence of UK 14,304. The inhibitory effect of UK 14,304 on ductal secretion is not mediated by the apical cholangiocyte NHE3. α2-Adrenergic receptors play a role in counterregulating enhanced ductal secretion associated with cholangiocyte proliferation in chronic cholestatic liver diseases.
Contribution of epoxyeicosatrienoic acids to flow-induced dilation in arteries of male ERα knockout mice: role of aromatase
Authors: Sun Dong , Yan Changdong , Jacobson Azita , Jiang Houli , Carroll Mairead A. , Huang An
Published: July 2007

We studied the roles of estrogen receptors (ER) and aromatase in the mediation of flow-induced dilation (FID) in isolated arteries of male ERα-knockout (ERα-KO) and wild-type (WT) mice. FID was comparable between gracilis arteries of WT and ERα-KO mice. In WT arteries, inhibition of NO and prostaglandins eliminated FID. In ERα-KO arteries, Nω-nitro-l-arginine methyl ester (l-NAME) inhibited FID by ∼26%, whereas indomethacin inhibited dilations by ∼50%. The remaining portion of the dilation was abolished by additional administration of 6-(2-proparglyoxyphenyl)hexanoic acid (PPOH) or iberiotoxin, inhibitors of epoxyeicosatrienoic acid (EET) synthesis and large-conductance potassium channels, respectively. By using an electrophysiological technique, we found that, in the presence of 10 dyne/cm2 shear stress, perfusate passing through donor vessels isolated from gracilis muscle of ERα-KO mice subjected to l-NAME and indomethacin elicited smooth muscle hyperpolarization and a dilator response of endothelium-denuded detector vessels. These responses were prevented by the presence of iberiotoxin in detector or PPOH in donor vessels. Gas chromatography-mass spectrometry (GC-MS) analysis indicated a significant increase in arterial production of EETs in ERα-KO compared with WT mice. Western blot analysis showed a significantly reduced endothelial nitric oxide synthase expression but enhanced expressions of aromatase and ERβ in ERα-KO arteries. Treatment of ERα-KO arteries with specific aromatase short-interfering RNA for 72 h, knocked down the aromatase mRNA and protein associated with elimination of EET-mediation of FID. Thus, FID in male ERα-KO arteries is maintained via an endothelium-derived hyperpolarizing factor/EET-mediated mechanism compensating for reduced NO mediation due, at least in part, to estrogen aromatized from testosterone.
Rat and hamster species differences in susceptibility to elastase-induced pulmonary emphysema relate to differences in elastase inhibitory capacity
Authors: Borzone Gisella , Liberona Leonel , Olmos Pablo , Sáez Claudia , Meneses Manuel , Reyes Tatiana , Moreno Rodrigo , Lisboa Carmen
Published: July 2007

Syrian Golden hamsters develop severe emphysema after a single intratracheal dose of elastase, whereas Sprague-Dawley rats exhibit mild emphysema with the same dose per kilogram body weight. We hypothesized that the development of severe emphysema is prevented in rats by the high serum level of α1-antitrypsin reported in rats, compared with hamsters, which provides for a high lung elastase inhibitory capacity (EIC). To explore this possibility, we challenged the antiprotease system of the rats by treating them with three similar weekly doses of elastase. Four months after treatment, we evaluated changes in histology, volume, and elastic properties of rat lungs and compared them with those of hamsters receiving a single dose of elastase. We also measured serum α1-antitrypsin levels and serum and lung EIC in control rats and hamsters. Results showed that, in association with 40% less serum and lung EIC compared with rats ( P < 0.001), hamster lungs had upper-lobe bullae formation, severe microscopic emphysema, a fourfold increase in lung volume ( P < 0.01) and a threefold increase in constant k, an index of compliance, of the lung deflation pressure-volume curve ( P < 0.01). In contrast, rats developed mild emphysema, with only 50% increase in volume ( P < 0.05) and 60% increase in constant k ( P < 0.01). In conclusion, two species that differ in serum and lung EIC exhibit significant differences in emphysema development after elastase. Rats with high EIC, despite receiving three doses of elastase, showed significantly less derangement of morphological and physiological parameters than hamsters with low EIC receiving a single dose.
Detection of early changes in renal function using 99mTc-MAG3 imaging in a murine model of ischemia-reperfusion injury
Authors: Roberts John , Chen Bo , Curtis Lisa M. , Agarwal Anupam , Sanders Paul W. , Zinn Kurt R.
Published: July 2007

Accurate determination of renal function in mice is a major impediment to the use of murine models in acute kidney injury. The purpose of this study was to determine whether early changes in renal function could be detected using dynamic gamma camera imaging in a mouse model of ischemia-reperfusion (I/R) injury. C57BL/6 mice ( n = 5/group) underwent a right nephrectomy, followed by either 30 min of I/R injury or sham surgery of the remaining kidney. Dynamic renal studies (21 min, 10 s/frame) were conducted before surgery (baseline) and at 5, 24, and 48 h by injection of 99mTc-mercaptoacetyltriglycine (MAG3; ∼1.0 mCi/mouse) via the tail vein. The percentage of injected dose (%ID) in the kidney was calculated for each 10-s interval after MAG3 injection, using standard region of interest analyses. A defect in renal function in I/R-treated mice was detected as early as 5 h after surgery compared with sham-treated mice, identified by the increased %ID (at peak) in the I/R-treated kidneys at 100 s ( P < 0.01) that remained significantly higher than sham-treated mice for the duration of the scan until 600 s ( P < 0.05). At 48 h, the renal scan demonstrated functional renal recovery of the I/R mice and was comparable to sham-treated mice. Our study shows that using dynamic imaging, renal dysfunction can be detected and quantified reliably as early as 5 h after I/R insult, allowing for evaluation of early treatment interventions.
WNK4-mediated regulation of renal ion transport proteins
Authors: Peng Ji-Bin , Warnock David G.
Published: July 2007

Point mutations in WNK4 [for With No K (lysine)], a serine-threonine kinase that is expressed in the distal nephron of the kidney, are linked to familial hyperkalemic hypertension (FHH). The imbalanced electrolyte homeostasis in FHH has led to studies toward an understanding of WNK4-mediated regulation of ion transport proteins in the kidney. A growing number of ion transport proteins for Na+, K+, Ca2+, and Cl−, including ion channels and transporters in the transcellular pathway and claudins in the paracellular pathway, are shown to be regulated by WNK4 from studies using models ranging from Xenopus laevis oocytes to transgenic and knockin mice. WNK4 regulates these transport proteins in different directions and by different cellular mechanisms. The common theme of WNK4-mediated regulation is to alter the abundance of ion transport proteins at the plasma membrane, with the exception of claudins, which are phosphorylated in the presence of WNK4. The regulation of WNK4 can be blocked by the full-length WNK1, whose action is in turn antagonized by a kidney-specific WNK1 variant lacking the kinase domain. In addition, WNK4 also activates stress-related serine-threonine kinases to regulate members of the SLC12 family members of cation-chloride cotransporters. In many cases, the FHH-causing mutants of WNK4 exhibit differences from wild-type WNK4 in regulating ion transport proteins. These regulations well explain the clinical features of FHH and provide insights into the multilayered regulation of ion transport processes in the distal nephron.
Sepsis induces an increase in thick ascending limb Cox-2 that is TLR4 dependent
Authors: El-Achkar Tarek M. , Plotkin Zoya , Marcic Branislav , Dagher Pierre C.
Published: July 2007

Cyclooxygenase-2 (Cox-2) is an inducible enzyme responsible for the formation of inflammatory prostanoids such as prostaglandins and thromboxane. Its role in the pathophysiology of inflammatory states like sepsis is increasingly recognized. Recently, we demonstrated that sepsis upregulates the endotoxin receptor Toll-like receptor 4 (TLR4) in rat kidney. Because Cox-2 is one of the downstream products of TLR4 activation, we hypothesized that sepsis-induced changes in renal Cox-2 expression are TLR4 dependent. Indeed, we show that in Sprague-Dawley rats, cecal ligation and puncture (a sepsis model) increases Cox-2 expression in cortical and medullary thick ascending loops (cTAL and mTAL, respectively) as well as inner medullary collecting ducts. These are all sites of increased TLR4 expression during sepsis. To determine the actual dependence on TLR4, we measured Cox-2 expression in wild-type and mutant mice which harbor a TLR4 gene deletion ( TLR4−/−). In wild-type mice, sepsis increased Cox-2 expression in proximal tubules, cTAL, and mTAL. In contrast, septic TLR4−/− mice showed no significant increase in cTAL or mTAL Cox-2 expression. Furthermore, renin was absent from juxtaglomerular cells of TLR4−/− mice. We conclude that the dependence of sepsis-induced renal Cox-2 expression on TLR4 is tubule specific. The TLR4-dependent Cox-2 expression is mostly restricted to cortical and medullary thick ascending loops of Henle that characteristically express and secrete Tamm-Horsfall protein.
ATP-sensitive potassium channels: metabolic sensing and cardioprotection
Authors: Zingman L. V. , Alekseev A. E. , Hodgson-Zingman D. M. , Terzic A.
Published: July 2007

The cardiovascular system operates under a wide scale of demands, ranging from conditions of rest to extreme stress. How the heart muscle matches rates of ATP production with utilization is an area of active investigation. ATP-sensitive potassium (KATP) channels serve a critical role in the orchestration of myocardial energetic well-being. KATP channel heteromultimers consist of inwardly-rectifying K+ channel 6.2 and ATP-binding cassette sulfonylurea receptor 2A that translates local ATP/ADP levels, set by ATPases and phosphotransfer reactions, to the channel pore function. In cells in which the mobility of metabolites between intracellular microdomains is limited, coupling of phosphotransfer pathways with KATP channels permits a high-fidelity transduction of nucleotide fluxes into changes in membrane excitability, matching energy demands with metabolic resources. This KATP channel-dependent optimization of cardiac action potential duration preserves cellular energy balance at varying workloads. Mutations of KATP channels result in disruption of the nucleotide signaling network and generate a stress-vulnerable phenotype with excessive susceptibility to injury, development of cardiomyopathy, and arrhythmia. Solving the mechanisms underlying the integration of KATP channels into the cellular energy network will advance the understanding of endogenous cardioprotection and the development of strategies for the management of cardiovascular injury and disease progression.
Fueling shivering thermogenesis during passive hypothermic recovery
Authors: Haman François , Scott Chris G. , Kenny Glen P.
Published: July 2007

In humans, the relative importance of oxidative fuels for sustaining shivering during passive hypothermic recovery or rewarming is still unclear. The main goals of this study were 1) to quantify the respective contributions of lipids and carbohydrates (CHO) during passive rewarming and 2) to determine the effects of precooling exercise on the pattern of fuel utilization. With indirect calorimetry methodologies, changes in fuel metabolism were quantified in nonacclimatized adult men shivering to rewarm from moderate hypothermia (core temperature ∼34.5°C) not following (Con) or following a precooling exercise at 75% V̇o2max for 15 min (Pre-CE). As hypothermic individuals shiver to normothermia, results showed that CHO dominate at all shivering intensities above 50% Shivpeak, while lipids were preferred at lower intensities. This change in the relative importance of CHO and lipids to total heat production was dictated entirely by modulating CHO oxidation rate, which decreased by as much as 10-fold from the beginning to the end of rewarming (from 1,611 ± 396 to 141 ± 361 mg/min for Con and 1,555 ± 230 to 207 ± 261 mg/min for Pre-CE). In contrast, lipid oxidation rate remained constant and low (relatively to maximal rates at exercise) throughout rewarming, averaging 183 ± 141 for Con and 207 ± 118 mg lipids/min for Pre-CE. In addition, this pattern of fuel selection remained the same between treatments. We concluded that fuel selection is regulated entirely by changes in CHO oxidation rate. Further research should focus on establishing the exact regulatory processes involved in achieving this large upregulation of CHO utilization rate following hypothermia.
Neoadjuvant Docetaxel and Capecitabine and the Use of Thymidine Phosphorylase as a Predictive Biomarker in Breast Cancer
Authors: Layman Rachel M. , Thomas Dafydd G. , Griffith Kent A. , Smerage Jeffrey B. , Helvie Mark A. , Roubidoux Marilyn A. , Diehl Kathleen M. , Newman Lisa A. , Sabel Michael S. , Hayman James A. , Pierce Lori J. , Hayes Daniel F. , Schott Anne F.
Published: July 2007

Purpose: Thymidine phosphorylase (TP) induction by docetaxel is a proposed mechanism for the observed preclinical synergy of docetaxel and capecitabine (DC). We evaluated whether TP protein expression is increased by docetaxel and correlates with pathologic complete response (pCR) in breast cancer patients.

Experimental Design: Women with stage II to III breast cancer were given four cycles of neoadjuvant docetaxel 36 mg/m2 i.v. over 30 min on days 1, 8, and 15 and capecitabine 2,000 mg/d, in two divided doses, on days 5 to 21 of a 28-day cycle. Radiology-directed biopsies of the breast tumors were done at baseline and 5 days after the first dose of docetaxel to evaluate TP expression. Following DC therapy, patients had core breast biopsies, and if residual disease was present, received four cycles of standard dose-dense doxorubin and cyclophosphamide (AC).

Results: The pCR rate was 26.9% (95% confidence interval, 11.6-47.8). Up-regulation of TP expression was not observed by either quantitative immunofluorescence (QIF) or immunohistochemistry. Radiology-directed core biopsy after neoadjuvant chemotherapy accurately predicted pathologic response in 88% (95% confidence interval, 69.8-97.6) of the cases. Neither level of TP expression nor TP up-regulation correlated with pCR. Significant toxicity resulted in therapy discontinuation in 3 of 26 patients.

Conclusions: DC chemotherapy exhibited a similar pCR rate compared with standard taxane regimens, with increased toxicity. TP expression was not up-regulated after docetaxel and did not correlate with therapeutic response. Core breast biopsy after neoadjuvant chemotherapy accurately predicted pathologic response.
Significance of Immunohistochemical Expression of Estrogen Receptors α and β in Squamous Cell Carcinoma of the Esophagus
Authors: Nozoe Tadahiro , Oyama Tsunehiro , Takenoyama Mitsuhiro , Hanagiri Takeshi , Sugio Kenji , Yasumoto Kosei
Published: July 2007

Purpose: Possible significance of sex hormone estrogen as an antitumor therapeutic arm toward esophageal squamous cell carcinoma (ESCC) cells has been suggested. The aim of the current study was to clarify the clinicopathologic significance of an immunohistochemical expression of estrogen receptors α and β (ERα and ERβ) in ESCC.

Experimental Design: Expression of ERα and ERβ were examined using an immunohistochemical methods in 73 paraffin-embedded sections collected from patients with ESCC who had been subjected to esophageal resection and digestive reconstruction without any preoperative induction therapy.

Results: Forty-seven (64.4%) ESCCs had a positive cytoplasmic expression of ERα and 21 (28.8%) ESCCs had a positive nuclear expression of ERβ. Univariate analysis showed that both positive ERα expression (P = 0.0001) and negative ERβ expression (P = 0.026) were unfavorable prognostic indicators in ESCC. Moreover, multivariate analysis showed that ERα-positive/ERβ-negative expression (P = 0.003) and progression of tumor stage (P = 0.014) were found to be independent unfavorable prognostic indicators in ESCCs.

Conclusions: Immunohistochemical expression of ERα and ERβ were found to be observed in ESCC. Positive expression of ERα in addition to negative expression of ERβ proved to be an unfavorable independent prognostic indicator in ESCC.
Endothelial Precursor Cell Migration During Vasculogenesis
Authors: Schmidt Annette , Brixius Klara , Bloch Wilhelm
Published: July 2007

Migration of endothelial precursor cells (so-called “angioblasts” in embryos and “endothelial progenitor cells” in adults) during vasculogenesis is a requirement for the formation of a primary vascular plexus. The migration is initiated by the change of endothelial precursors to their migratory phenotype. The endothelial precursor cells are then guided to the position where the primary vascular plexus is formed. Migration is stopped by the reversion of the cells to their nonmigratory phenotype. A combination of regulatory mechanisms and factors controls this process. These include gradients of soluble factors, extracellular matrix–cell interaction and cell–cell interaction. In this review, we give an overview of the regulation of angioblast migration during embryonic vasculogenesis and its relationship to the migration of endothelial progenitors during postnatal vascular development.