bluuebunny/crossref_metadata_2025 huggingface dataset:
Interspecies Signaling between
Veillonella atypica
and
Streptococcus gordonii
Requires the Transcription Factor CcpA
Authors: Johnson Bart P. , Jensen Benjamin J. , Ransom Eric M. , Heinemann Kimberly A. , Vannatta Kelley M. , Egland Kristi A. , Egland Paul G.
Published: June 2009

Streptococcus gordonii
and
Veillonella atypica
, two early-colonizing members of the dental plaque biofilm, participate in a relationship that results in increased transcription of the
S. gordonii
gene
amyB
, encoding an α-amylase. We show that the transcription factor CcpA is required for this interspecies interaction.
Molecular profile of ductal carcinoma in situ of the breast inBRCA1andBRCA2germline mutation carriers
Authors: van der Groep P , van Diest P J , Menko F H , Bart J , de Vries E G E , van der Wall E
Published: June 2009

Aims:

Ductal carcinoma in situ (DCIS) is an established late precursor of sporadic invasive breast cancer and to a large extent parallels its invasive counterpart with respect to molecular changes and immunophenotype. Invasive breast cancers in germlineBRCA1andBRCA2mutation carriers have a distinct “basal” and “luminal” immunophenotype, respectively, but the immunophenotype of their precursor lesions has hardly been studied, and this was the aim of this study.

Methods:

DCIS lesions of 25 provenBRCA1and 9 provenBRCA2germline mutation carriers and their 22 and 6, respectively, accompanying invasive lesions were stained by immunohistochemistry for oestrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor (HER)2/neu, cytokeratin (CK)5/6, CK14, epidermal growth factor receptor (EGFR) and Ki67.

Results:

DCIS lesions inBRCA1mutation carriers were mostly of the basal molecular type with low ER/PR/HER2 expression, while they frequently expressed CK5/6, CK14 and EGFR, and were mostly grade 3 and highly proliferative. DCIS lesions inBRCA2mutation carriers were mostly of luminal molecular type with frequent expression of ER/PR, and infrequent expression of CK5/6, CK14 and EGFR, and they were mostly grade 3 and showed low proliferation. InBRCA1andBRCA2mutation carriers there was a high concordance between DCIS lesions and their concomitant invasive counterpart with regard to expression of individual markers as well as “molecular” subtype.

Conclusions:

Although the number of cases studied was low, DCIS lesions inBRCA1andBRCA2mutations carriers are usually of the basal and luminal molecular type, respectively, similar to their accompanying invasive cancers, thereby providing evidence that DCIS is a direct precursor lesion in these hereditary predisposed patients. This also suggests that crucial carcinogenetic events leading to these phenotypes in hereditary predisposed patients occur before the stage of invasion.
Viscoplastic constitutive approach for rate-sensitive structured clays
Authors: Hinchberger Sean D. , Qu Guangfeng
Published: June 2009

This paper extends an existing elastic–viscoplastic (EVP) constitutive model using a state-dependent viscosity parameter to describe the engineering response of undisturbed structured clay. The term structure refers to the effects of fabric and weak cementation bonds between clay particles. The extended constitutive model is coupled with the Biot consolidation theory and is formulated to describe the intrinsic or unstructured response of clay using overstress viscoplasticity, an elliptical cap yield surface, Drucker–Prager failure envelope, and a hardening law from critical state theory. The clay structure is mathematically accounted for by assuming that the initial fluidity of structured clay at yield and failure is very low and that the fluidity increases with increasing plastic strain. This process is usually referred to as “destructuration.” The formulation is evaluated using Saint-Jean-Vianney (SJV) clay by comparing calculated and measured behaviour during consolidated isotropically undrained triaxial compression, triaxial creep, and constant rate-of-strain Ko′-consolidation tests. The comparisons indicate that the EVP constitutive model can describe most of the rate-sensitive behaviour of SJV clay during both drained and undrained laboratory tests involving either constant-volume shear or predominantly volumetric compression of the soil skeleton.
Flume deposition modeling of caustic and noncaustic oil sand tailings
Authors: Miller W. G. , Scott J. D. , Sego D. C.
Published: June 2009

As part of an overall study to evaluate the properties and processes influencing the rate and magnitude of consolidation for oil sand tailings produced using different extraction processes, laboratory flume deposition tests were carried out with the objective to hydraulically deposit oil sand tailings and compare the effects of caustic and noncaustic extraction processes on the nature of beach deposits in terms of geometry, grain-size distribution, and density. The characteristics of the beaches from this research study were compared with other flume deposition test results performed using a variety of tailings materials. A good correlation exists between flume deposition test results using oil sand tailings and the various other tailings materials, especially those with appreciable fines contents with respect to parameters that govern beach slope. These comparisons show the reliability and effectiveness of flume deposition tests in terms of establishing general relationships and can serve as a guide to predict beach slopes.
Detection of smear zone using micro-cone and electrical resistance probe
Authors: Shin Dong-Hyun , Lee Changho , Lee Jong-Sub , Lee Woojin
Published: June 2009

The installation of a prefabricated vertical drain (PVD) using a mandrel results in soil disturbance adjacent to the PVD, which is known as the smear zone. The smear zone is investigated by a series of radial penetration tests including a micro-cone penetrometer and an electrical resistance probe in the clay specimen prepared in a large-scale chamber. The 5 mm diameter micro-cone penetrometer and the 2.1 mm diameter electrical resistance probe produce continuous soil strength and electrical resistivity profiles around the PVD. Almost-constant values of the cone tip resistance and electrical resistivity are measured within the undisturbed zone. The outer boundary of the smear zone is clearly defined by the locations where the deviations of the measured cone tip resistance and electrical resistivity from the constant values are observed. Significant changes in both measurements are observed in the smear zone with remarkably consistent patterns. The smear zone induced by the PVD installation using a rectangular mandrel has an elliptical shape and extends to approximately 3.2∼3.4 times the half-length of the mandrel and 5.3∼5.4 times the half-width of the mandrel.
Oxyhalogen–sulfur chemistry — Kinetics and mechanism of oxidation of methionine by aqueous iodine and acidified iodate
Authors: Chikwana Edward , Davis Bradley , Morakinyo Moshood K. , Simoyi Reuben H.
Published: June 2009

The oxidation of methionine (Met) by acidic iodate and aqueous iodine was studied. Though the reaction is a simple two-electron oxidation to give methionine sulfoxide (Met–S=O), the dynamics of the reaction are, however, very complex, characterized by clock reaction characteristics and transient formation of iodine. In excess methionine conditions, the stoichiometry of the reaction was deduced to be IO3– + 3Met → I– + 3Met–S=O. In excess iodate, the iodide product reacts with iodate to give a final product of molecular iodine and a 2:5 stoichiometry: 2IO3– + 5Met + 2H+→ I2 + 5Met–S=O + H2O. The direct reaction of iodine and methionine is slow and mildly autoinhibitory, which explains the transient formation of iodine, even in conditions of excess methionine in which iodine is not a final product. The whole reaction scheme could be simulated by a simple network of 11 reactions.
Chemical-bond properties and hardness of nonlinear optical crystals LiB3O5 and β-BaB2O4
Authors: Zhao Guangping , Yu Bingjie
Published: June 2009

The chemical-bond parameters of LiB3O5 (LBO) and β-BaB2O4 (BBO) nonlinear optical crystals have been calculated using the chemical-bond theory of complex crystals. Their hardnesses have been predicted by the chemical-bond definition of hardness. The calculated results indicate that their hardnesses are determined only by Li–O and Ba–O bonds. The BO3 anionic clusters do not contribute to their hardness. The calculation of hardness indicates that all of the compounds possess good mechanical properties.
γ-Silylated α,β-unsaturated amides — Preparation by [1,5]-sigmatropic rearrangement and use as masked dienolate equivalents in carbonyl condensations
Authors: Green James R. , Alo Babajide I. , Majewski Marek , Snieckus Victor
Published: June 2009

The reaction of lithium dienolates derived from N,N-dialkylsenecioamides (1a–1c) with triorganosilyl electrophiles occurs initially at the oxygen atom predominantly, and is followed by an O → C silicon migration to afford the γ-silylated senecioamides (4a–4h). The γ-silylated senecioamide Z-4a undergoes fluoride-ion-mediated condensations with aromatic aldehydes to give kinetic α-(6) and thermodynamic γ-(5) condensation product patterns comparable to lithium dienolates. The TiCl4-mediated reactions with aldehydes gives α-products (6) in a highly syn-selective manner. Possible transition-state models for the syn-selective condensations are discussed and a chair-like transition state featuring bidentate coordination to titanium (11) is proposed.
Synthesis, characterization, and surface studies of conjugated polymers possessing 2,2′-biimidazole moieties
Authors: Walker D. T. , Douglas C. D. , MacLean B. J.
Published: June 2009

Two novel 2,2′-biimidazole-thiophene structures, 5,5′-bis(2,2′-bithiophene-5-yl)-1,1′-dimethyl-2,2′-biimidazole and 5,5′-bis(3,4-ethylenedioxythiophene-2-yl)-1,1′-dimethyl-2,2′-biimidazole, have been synthesized and electrochemically polymerized. These materials underwent facile oxidation on Pt and ITO surfaces in CH2Cl2/Bu4NPF6 to yield conjugated, electroactive polymer films. The films were characterized with cyclic voltammetry, electronic absorption spectroscopy, and atomic force microscopy.
Synthesis of a new heterocyclic system — Fluoreno[1,2-d]imidazol-10-one
Authors: Rahimizadeh Mohammad , Pordel Mehdi , Bakavoli Mehdi , Rezaeian Shima , Eshghi Hossein
Published: June 2009

Synthesis of various substituted fluoreno[1,2-d]imidazol-10-ones (5a–5g) has been accomplished by the cyclization of diazotized 1-substituted 4-benzoyl-5- aminobenzimidazoles (4a–4g). Compounds 4a–4g were prepared by reductive ring opening of 3H-imidazo[4′,5′:3,4]benzo[c]isoxazoles (3a–3g) with zinc dust in EtOH/NaOH solution.
Stable phenylene- and biphenylene-bis(isobenzofuran)s related to diphenylisobenzofuran
Authors: Klassen Sheri A. , Boehme Richard , Derrick Sean D. , Moock Klaus , Baker A. Elizabeth , Fogg Deryn E. , Boeré René T. , Dibble Peter W.
Published: June 2009

A series of phenyl-substituted bis(isobenzofuran)s in which the furan moieties are linked by 1,3-phenylene, 1,4-phenylene, or 4,4′-biphenylene linkers have been prepared in only two steps. They are comparable to diphenylisobenzofuran in their absorption and luminescent properties, their electrochemistry, and their reactivity. Their degree of similarity to diphenylisobenzofuran was found to depend significantly on the nature of the linking group. Diels–Alder reaction of the title compounds and subsequent aromatization gave very rapid access to penta- or hexa-aryl products.
Novel formation of isoxazoline N-oxide in addition to Michael adduct from the reaction of β-nitrostyrenes with 2-methoxyfuran — Experimental and theoretical studies
Authors: Itoh Kuniaki , Kishimoto Shigehisa , Sagi Kazuo
Published: June 2009

2-Methoxyfuran reacts with β-nitrostyrenes to give Michael adducts. Interestingly, isoxazoline N-oxides were obtained in the reactions with β-nitrostyrenes possessing additional electron-withdrawing groups [COPh (2f) and CO2Et (2g)]. (Z)-Nitrostyrene (2g) gives trans-isoxazoline (4g) and (E)-nitrostyrene (2f) leads to the cis-form product 4f. We have used theoretical methods to investigate the mechanism and to probe the regio- and stereo-selectivity observed in the rearrangement and the Michael reactions. To account for the selectivity observed in these reactions, we examined the Fukui functions and located the transition states (TS) using density functional theory (DFT) calculations at the B3LYP/6–31G* level. The first step involves a nucleophilic attack by the α-carbon atom (C4) of the furan ring on the vinyl C-atom (C5) of the nitrostyrene part to give a zwitterionic intermediate (IN1). Fission of the C–O bond of the furan ring in the intermediate and ring closure via the oxygen atom (endo-O atom) of the nitro group gives the isoxazoline N-oxide. Alternatively, the intermediate (IN1) may be transformed into the Michael adduct by an intramolecular proton transfer mediated by the formation of a four-membered transition-state structure. The potential-energy barriers for these reactions had the following values: 5.1 kcal/mol for 2f and 17.0 kcal/mol for 2g′ (CO2Me) at the rearrangement step, and 41–49 kcal/mol for the proton-transfer step. The solvent effect in CHCl3 stabilized the electrophilic attack by 1–14 kcal/mol. DFT analysis of these reactions is in good agreement with the experimental results.
Interdisciplinary Translational Research in Anthropology, Nutrition, and Public Health
Authors: McGarvey Stephen T.
Published: June 2009

This review focuses on several human population health research topics that exemplify interdisciplinary concepts and approaches from anthropology, nutrition, and public health with an emphasis on applied or translational global health implications. First, a recent study on neonatal survival in a resource-poor region emphasizes how health can be markedly improved with detailed translation and implementation of evidence from all three disciplines. Second, schistosomiasis, a parasitic worm infection, is reviewed with an emphasis on developing a consensus of its nutritional health burdens and the next translational research steps needed to improve control of both infection transmission and disease. Last, the author's long-term Samoan nutrition and health studies are described with a focus on new translational research to improve diabetes. This selective review attempts to provide a rationale for the intersections of anthropology, nutrition, and public health to proceed with fundamental biological, cultural, and behavioral research to reduce health inequalities globally and domestically.
Developmental Origins of Adult Function and Health: Evolutionary Hypotheses
Authors: Kuzawa Christopher W. , Quinn Elizabeth A.
Published: June 2009

Many biological systems have critical periods that overlap with the age of maternal provisioning via placenta or lactation. As such, they serve as conduits for phenotypic information transfer between generations and link maternal experience with offspring biology and disease outcomes. This review critically evaluates proposals for an adaptive function of these responses in humans. Although most models assume an adult function for the metabolic responses to nutritional stress, these specific traits have more likely been tailored for effects during fetal life and infancy. Other biological functions are under stronger evolutionary selection later in life and thus are better candidates for predictive plasticity. Given the long human life cycle and environmental changes that are unpredictable on decadal timescales, plastic responses that evolved to confer benefits in adolescence or adulthood likely rely on cues that integrate matrilineal experiences prior to gestation. We conclude with strategies for testing the timescale and adaptive significance of developmental responses to early environments.
Dose-dependent activation of distinct hypertrophic pathways by serotonin in cardiac cells
Authors: Villeneuve C. , Caudrillier A. , Ordener C. , Pizzinat N. , Parini A. , Mialet-Perez J.
Published: June 2009

There is substantial evidence supporting a hypertrophic action of serotonin [5-hydroxytryptamine (5-HT)] in cardiomyocytes. However, little is known about the mechanisms involved. We previously demonstrated that 5-HT-induced hypertrophy depends, in part, on the generation of reactive oxygen species by monoamine oxidase-A (MAO-A) (see Ref. 3 ). Cardiomyocytes express 5-HT2 receptors, which may also participate in hypertrophy. Here, we analyzed the respective contribution of 5-HT2 receptors and MAO-A in H9C2 cardiomyoblast hypertrophy. 5-HT induced a dose-dependent increase in [3H]leucine incorporation and stimulation of two markers of cardiac hypertrophy, ANF-luc and αSK-actin-luc reporter genes. Experiments using 1 μM 5-HT showed that hypertrophic response occurred independently from MAO-A. Using pharmacological inhibitors (M100907 and ketanserin), we identified a novel mechanism of action involving 5-HT2A receptors and requiring Ca2+/calcineurin/nuclear factor of activated T-cell activation. The activation of this hypertrophic pathway was fully prevented by 5-HT2A inhibitors and was unaffected by MAO inhibition. When 10 μM 5-HT was used, an additional hypertrophic response, prevented by the MAO inhibitors pargyline and RO 41-1049, was observed. Unlike the 5-HT2A-receptor-mediated H9C2 cell hypertrophy, MAO-A-dependent hypertrophic response required activation of extracellular-regulated kinases. In conclusion, our results show the existence of a dose-dependent shift of activation of distinct intracellular pathways involved in 5-HT-mediated hypertrophy of cardiac cells.
Lysozyme, a mediator of sepsis that intrinsically generates hydrogen peroxide to cause cardiovascular dysfunction
Authors: Mink Steven N , Jacobs Hans , Cheng Zhao-Qin , Kasian Krika , Santos-Martinez Luis E , Light R. Bruce
Published: June 2009

In septic shock, cardiovascular collapse is caused by the release of inflammatory mediators. We previously found that lysozyme (Lzm-S), released from leukocytes, contributed to the myocardial depression and arterial vasodilation that develop in canine models of septic shock. To cause vasodilation, Lzm-S generates hydrogen peroxide (H2O2) that activates the smooth muscle soluble guanylate cyclase (sGC) pathway, although the mechanism of H2O2generation is not known. To cause myocardial depression, Lzm-S binds to the endocardial endothelium, resulting in the formation of nitric oxide (NO) and subsequent activation of myocardial sGC, although the initial signaling event is not clear. In this study, we examined whether the myocardial depression produced by Lzm-S was also caused by the generation of H2O2and whether Lzm-S could intrinsically generate H2O2as has been described for other protein types. In a canine ventricular trabecular preparation, we found that the peroxidizing agent Aspergillus niger catalase, that would breakdown H2O2, prevented Lzm-S- induced decrease in contraction. We also found that compound I, a species of catalase formed during H2O2metabolism, could contribute to the NO generation caused by Lzm-S. In tissue-free experiments, we used a fluorometric assay (Ultra Amplex red H2O2assay) and electrochemical sensor techniques, respectively, to measure H2O2generation. We found that Lzm-S could generate H2O2and, furthermore, that this generation could be attenuated by the singlet oxygen quencher sodium azide. This study shows that Lzm-S, a mediator of sepsis, is able to intrinsically generate H2O2. Moreover, this generation may activate H2O2-dependent pathways leading to cardiovascular collapse in septic shock.
Phenylephrine and sustained acidosis activate the neonatal rat cardiomyocyte Na+/H+exchanger through phosphorylation of amino acids Ser770and Ser771
Authors: Coccaro Ersilia , Karki Pratap , Cojocaru Cicerone , Fliegel Larry
Published: June 2009

The mammalian Na+/H+exchanger isoform 1 (NHE1) is a ubiquitously expressed membrane protein that regulates intracellular pH in the myocardium. NHE1 is also important in mediating myocardial hypertrophy, and the blockage of NHE1 activity prevents hypertrophy and reduces ischemia-reperfusion injury in animal models. We recently demonstrated that extracellular-regulated kinase (ERK)-mediated activation of NHE1 occurs during ischemia-reperfusion of the myocardium. To understand the regulation of NHE1 in the myocardium by phosphorylation, we expressed a series of adenoviruses that express wild-type and mutant cDNA for NHE1. All exogenous cDNA for NHE1 had additional mutations [Leu163Phe/Gly174Ser], which increases NHE1 resistance to EMD-87580 (a specific blocker of NHE1) 100-fold, and allowed the measurement of exogenous NHE1 while inhibiting endogenous NHE1. By examining the effects of a series of mutations of the NHE1 cytosolic region, we determined that the amino acids Ser770and Ser771were essential for the acute activation of NHE1 activity in rat cardiomyocytes. The specific mutation of either residue prevented the rapid activation of exchanger activity by a sustained intracellular acidosis through ERK-dependent pathways. The same amino acids were critical to phenylephrine-mediated, ERK-dependent activation of NHE1 activity and increased the phosphorylation in intact rat cardiomyocytes. The results demonstrate that both sustained intracellular acidosis and phenylephrine rapidly activate the NHE1 protein in intact cardiac cells through ERK-dependent pathways that act on a common pathway mediated by amino acids Ser770and Ser771of the cytosolic tail of the protein.
Cholinergic receptor signaling modulates spontaneous firing of sinoatrial nodal cells via integrated effects on PKA-dependent Ca2+cycling andIKACh
Authors: Lyashkov Alexey E. , Vinogradova Tatiana M. , Zahanich Ihor , Li Yue , Younes Antoine , Nuss H. Bradley , Spurgeon Harold A. , Maltsev Victor A. , Lakatta Edward G.
Published: June 2009

Prior studies indicate that cholinergic receptor (ChR) activation is linked to beating rate reduction (BRR) in sinoatrial nodal cells (SANC) via 1) a Gi-coupled reduction in adenylyl cyclase (AC) activity, leading to a reduction of cAMP or protein kinase A (PKA) modulation of hyperpolarization-activated current ( If) or L-type Ca2+currents ( ICa,L), respectively; and 2) direct Gi-coupled activation of ACh-activated potassium current ( IKACh). More recent studies, however, have indicated that Ca2+cycling by the sarcoplasmic reticulum within SANC (referred to as a Ca2+clock) generates rhythmic, spontaneous local Ca2+releases (LCR) that are AC-PKA dependent. LCRs activate Na+-Ca2+exchange (NCX) current, which ignites the surface membrane ion channels to effect an AP. The purpose of the present study was to determine how ChR signaling initiated by a cholinergic agonist, carbachol (CCh), affects AC, cAMP, and PKA or sarcolemmal ion channels and LCRs and how these effects become integrated to generate the net response to a given intensity of ChR stimulation in single, isolated rabbit SANC. The threshold CCh concentration ([CCh]) for BRR was ∼10 nM, half maximal inhibition (IC50) was achieved at 100 nM, and 1,000 nM stopped spontaneous beating. Giinhibition by pertussis toxin blocked all CCh effects on BRR. Using specific ion channel blockers, we established that Ifblockade did not affect BRR at any [CCh] and that IKAChactivation, evidenced by hyperpolarization, first became apparent at [CCh] > 30 nM. At IC50, CCh reduced cAMP and reduced PKA-dependent phospholamban (PLB) phosphorylation by ∼50%. The dose response of BRR to CCh in the presence of IKAChblockade by a specific inhibitor, tertiapin Q, mirrored that of CCh to reduced PLB phosphorylation. At IC50, CCh caused a time-dependent reduction in the number and size of LCRs and a time dependent increase in LCR period that paralleled coincident BRR. The phosphatase inhibitor calyculin A reversed the effect of IC50CCh on SANC LCRs and BRR. Numerical model simulations demonstrated that Ca2+cycling is integrated into the cholinergic modulation of BRR via LCR-induced activation of NCX current, providing theoretical support for the experimental findings. Thus ChR stimulation-induced BRR is entirely dependent on Giactivation and the extent of Gicoupling to Ca2+cycling via PKA signaling or to IKACh: at low [CCh], IKAChactivation is not evident and BRR is attributable to a suppression of cAMP-mediated, PKA-dependent Ca2+signaling; as [CCh] increases beyond 30 nM, a tight coupling between suppression of PKA-dependent Ca2+signaling and IKAChactivation underlies a more pronounced BRR.
TLR3 activation stimulates cytokine secretion without altering agonist-induced human small airway contraction or relaxation
Authors: Cooper Philip R. , Lamb Roberta , Day Nicole D. , Branigan Patrick J. , Kajekar Radhika , San Mateo Lani , Hornby Pamela J. , Panettieri Reynold A.
Published: June 2009

Respiratory infections exacerbate chronic lung diseases promoting airway inflammation and hyperreactivity. Toll-like receptor 3 (TLR3) recognizes viral double-stranded (ds) RNA such as polyinosinic-polycytidylic acid [poly(I:C)] and stimulates innate immune responses. The objective of this study was to test the hypothesis that dsRNA promotes lung inflammation and alters airway responsiveness to cholinergic and β-adrenergic receptor agonists in human lung slices. Human airway smooth muscle (ASM) was incubated for 24 h in poly(I:C) ± TNFα and a TLR3 monoclonal antibody. Precision-cut lung slices (PCLS; 250-μm thickness) from healthy human lungs containing a small airway were incubated in 0, 10, or 100 μg/ml poly(I:C) for 24 h. Intravital microscopy of lung slices was used to quantify contractile and relaxation responsiveness to carbachol and isoproterenol, respectively. Supernatants of ASM and PCLS were analyzed for cytokine secretion using a 25-multiplex bead assay. In human ASM, poly(I:C) (0.5 μg/ml) increased macrophage inflammatory protein-1α (MIP-1α) and RANTES that was prevented by a TLR3 monoclonal receptor antibody. Incubation of human PCLS with poly(I:C) (10 and 100 μg/ml) had little effect on the log EC50or maximum drug effect (Emax) for contraction and relaxation in response to carbachol and isoproterenol, respectively. The responsiveness of the same human PCLS to poly(I:C) incubation was confirmed by the robust increase in chemokines and cytokines. In separate experiments, incubation of PCLS with IL-13 or TNFα (100 ng/ml) increased airway sensitivity to carbachol. Poly(I:C) promotes inflammatory mediator release that was not associated with enhanced bronchoconstriction or attenuated bronchodilation in normal healthy human lung slices. Transduction at the TLR3 initiated by dsRNA stimulates downstream innate immune responses.
Mepacrine inhibits subepithelial fibrosis by reducing the expression of arginase and TGF-β1in an extended subacute mouse model of allergic asthma
Authors: Mabalirajan Ulaganathan , Aich Jyotirmoi , Agrawal Anurag , Ghosh Balaram
Published: June 2009

Asthma is a dynamic disorder of airway inflammation and airway remodeling with an imbalance in T helper type 1 (Th1)/Th2immune response. Increased Th2cytokines such as IL-4 and IL-13 induce arginase either directly or indirectly through transforming growth factor-β1(TGF-β1) and lead to subepithelial fibrosis, which is a crucial component of airway remodeling. Synthetic antimalarials have been reported to have immunomodulatory properties. Mepacrine is known for its reduction of airway inflammation in short-term allergen challenge model by reducing Th2cytokines and cysteinyl leukotrienes, which has an important role in the development of airway remodeling features. Therefore, we hypothesized that mepacrine may reduce airway remodeling. For this, extended subacute ovalbumin mice model of asthma was developed; these mice showed an increased expression of profibrotic mediators, subepithelial fibrosis, and goblet cell metaplasia along with airway inflammation, increased Th2cytokines, allergen-specific IgE, IgG1, increased cytosolic PLA2(cPLA2), and airway hyperresponsiveness. Presence of intraepithelial eosinophils and significant TGF-β1expression in subepithelial mesenchymal regions by repeated allergen exposures indicate that asthmatic mice of this study have developed human mimicking as well as late stages of asthma. However, mepacrine treatment decreased Th2cytokines and subepithelial fibrosis and alleviated asthma features. These reductions by mepacrine were associated with a decrease in levels and expression of TGF-β1and the reduction in activity, expression of arginase in lung cytosol, and immunolocalization in inflammatory cells present in perivascular and peribronchial regions. These results suggest that mepacrine might reduce the development of subepithelial fibrosis by reducing the arginase and TGF-β1. These effects of mepacrine likely underlie its antiairway remodeling action in asthma.
UTP regulation of ion transport in alveolar epithelial cells involves distinct mechanisms
Authors: Yang Chuanxiu , Su Lijing , Wang Yang , Liu Lin
Published: June 2009

UTP is known to regulate alveolar fluid clearance. However, the relative contribution of alveolar type I cells and type II cells to this process is unknown. In this study, we investigated the effects of UTP on ion transport in type I-like cell (AEC I) and type II-like cell (AEC II) monolayers. Luminal treatment of cell monolayers with UTP increased short-circuit current ( Isc) of AEC II but decreased Iscof AEC I. The Cl−channel blockers NPPB and DIDS inhibited the UTP-induced changes in Isc(Δ Isc) in both types of cells. Amiloride, an inhibitor of epithelial Na+channels (ENaC), abolished the UTP-induced Δ Iscin AEC I, but not in AEC II. The general blocker of K+channels, BaCl2, eliminated the UTP-induced Δ Iscin AEC II, but not in AEC I. The intermediate conductance (IKCa) blocker, clofilium, also blocked the UTP effect in AEC II. The signal transduction pathways mediated by UTP were the same in AEC I and AEC II. Furthermore, UTP increased Cl−secretion in AEC II and Cl−absorption in AEC I. Our results suggest that UTP induces opposite changes in Iscin AEC I and AEC II, likely due to the reversed Cl−flux and different contributions of ENaC and IKCa. Our results further imply a new concept that type II cells contribute to UTP-induced fluid secretion and type I cells contribute to UTP-induced fluid absorption in alveoli.
Mechanical effects of obesity on airway responsiveness in otherwise healthy humans
Authors: Torchio Roberto , Gobbi Alessandro , Gulotta Carlo , Dellacà Raffaele , Tinivella Marco , Hyatt Robert E. , Brusasco Vito , Pellegrino Riccardo
Published: June 2009

We investigated whether obesity is associated with airway hyperresponsiveness in otherwise healthy humans and, if so, whether this correlates with a restrictive lung function pattern or a decreased number of sighs at rest and/or during walking. Lung function was studied before and after inhaling methacholine (MCh) in 41 healthy subjects with body mass index ranging from 20 to 56. Breathing pattern was assessed during a 60-min rest period and a 30-min walk. The dose of MCh that produced a 50% decrease in the maximum expiratory flow measured in a body plethysmograph (PD50MCh) was inversely correlated with body mass index ( r2 = 0.32, P < 0.001) and waist circumference ( r2 = 0.25, P < 0.001). Significant correlations with body mass index were also found with the maximum changes in respiratory resistance ( r2 = 0.19, P < 0.001) and reactance ( r2 = 0.40, P < 0.001) measured at 5 Hz. PD50MCh was also positively correlated with functional residual capacity ( r2 = 0.56, P < 0.001) and total lung capacity ( r2 = 0.59, P < 0.001) in men, but not in women. Neither PD50MCh nor body mass index correlated with number of sighs, average tidal volume, ventilation, or breathing frequency. In this study, airway hyperresponsiveness was significantly associated with obesity in otherwise healthy subjects. In obese men, but not in women, airway hyperresponsiveness was associated with the decreases in lung volumes.
Relationship between body mass index and adiposity in prepubertal children: ethnic and geographic comparisons between New York City and Jinan City (China)
Authors: Navder Khursheed P. , He Qing , Zhang Xiaojing , He Suyuan , Gong Luxia , Sun Yungao , Deckelbaum Richard J. , Thornton John , Gallagher Dympna
Published: June 2009

Body mass index (BMI) is often used as a surrogate estimate of percent body fat in epidemiological studies. This study tested the hypothesis that BMI is representative of body fatness independent of age, sex, ethnicity, and geographic location in prepubertal children. The study sample included a total of 605 prepubertal children (275 girls and 330 boys) of which 247 were Chinese from Jinan, Shandong, Mainland China, and 358 children were from various ethnic backgrounds in New York City (NYC): 121 Caucasians, 94 African Americans, and 143 Asians (Chinese and Korean). In this cross-sectional study, dual energy X-ray absorptiometry was used to quantify total body fat (TBF) and percent body fat (PBF). Prepubertal status was assessed by the criteria of Tanner. Multiple regression models were developed with TBF and PBF as the dependent variables and BMI, age, sex, and ethnicity as independent variables. Multiple regression analysis showed that BMI alone explained 85% and 69% of between-subject variance for TBF and PBF, respectively. Sex was a significant contributor to the models ( P < 0.001) with girls having higher TBF and PBF than boys. Ethnicity and geographic location were significant contributors to the model ( P < 0.0001) with Asians (Jinan and NYC Asians) having higher PBF than all non-Asian groups ( P < 0.0001), and Jinan Asians having higher TBF and PBF than NYC-Asians. Among prepubertal children, for the same BMI, Asians have significantly higher PBF compared with African Americans and Caucasians. Caution is warranted when applying BMI across sex and ethnic prepubertal groups.
Bronchodilator effects of exercise hyperpnea and albuterol in mild-to-moderate asthma
Authors: Milanese Manlio , Saporiti Riccardo , Bartolini Stefano , Pellegrino Riccardo , Baroffio Michele , Brusasco Vito , Crimi Emanuele
Published: June 2009

In asthmatic patients, either bronchodilatation or bronchoconstriction may develop during exercise. In 18 patients with mild-to-moderate asthma, we conducted two studies with the aims to 1) quantify the bronchodilator effect of hyperpnea induced by incremental-load maximum exercise compared with effects of inhaled albuterol ( study 1, n = 10) and 2) determine the time course of changes in airway caliber during prolonged constant-load exercise ( study 2, n = 8). In both studies, it was also investigated whether the bronchodilator effects of exercise hyperpnea and albuterol are additive. Changes in airway caliber were measured by changes in partial forced expiratory flow. In study 1, incremental-load exercise was associated with a bronchodilatation that was ∼60% of the maximal bronchodilatation obtainable with 1,500 μg of albuterol. In study 2, constant-load exercise was associated with an initial moderate bronchodilatation and a late airway renarrowing. In both studies, premedication with inhaled albuterol (400 μg) promoted sustained bronchodilatation during exercise, which was additive to that caused by exercise hyperpnea. In conclusion, in mild-to-moderate asthmatic individuals, hyperpnea at peak exercise was associated with a potent yet not complete bronchodilatation. During constant-load exercise, a transient bronchodilatation was followed by airway renarrowing, suggesting prevalence of constrictor over dilator effects of hyperpnea. Finally, the bronchodilator effect of hyperpnea was additive to that of albuterol.
Evaluation of individual skeletal muscle activity by glucose uptake during pedaling exercise at different workloads using positron emission tomography
Authors: Gondoh Yuichi , Tashiro Manabu , Itoh Masatoshi , Masud Mohammad M. , Sensui Hiroomi , Watanuki Shoichi , Ishii Kenji , Takekura Hiroaki , Nagatomi Ryoichi , Fujimoto Toshihiko
Published: June 2009

Skeletal muscle glucose uptake closely reflects muscle activity at exercise intensity levels <55% of maximal oxygen consumption (V̇o2max). Our purpose was to evaluate individual skeletal muscle activity from glucose uptake in humans during pedaling exercise at different workloads by using [18F]fluorodeoxyglucose (FDG) and positron emission tomography (PET). Twenty healthy male subjects were divided into two groups (7 exercise subjects and 13 control subjects). Exercise subjects were studied during 35 min of pedaling exercise at 40 and 55% V̇o2maxexercise intensities. FDG was injected 10 min after the start of exercise or after 20 min of rest. PET scanning of the whole body was conducted after completion of the exercise or rest period. In exercise subjects, mean FDG uptake [standardized uptake ratio (SUR)] of the iliacus muscle and muscles of the anterior part of the thigh was significantly greater than uptake in muscles of control subjects. At 55% V̇o2maxexercise, SURs of the iliacus muscle and thigh muscles, except for the rectus femoris, increased significantly compared with SURs at 40% V̇o2maxexercise. Our results are the first to clarify that the iliacus muscle, as well as the muscles of the anterior thigh, is the prime muscle used during pedaling exercise. In addition, the iliacus muscle and all muscles in the thigh, except for the rectus femoris, contribute when the workload of the pedaling exercise increases from 40 to 55% V̇o2max.
Effect of compliance and hematocrit on wall shear stress in a model of the entire coronary arterial tree
Authors: Huo Yunlong , Kassab Ghassan S.
Published: June 2009

A hemodynamic analysis is implemented in the entire coronary arterial tree of diastolically arrested, vasodilated pig heart that takes into account vessel compliance and blood viscosity in each vessel of a large-scale simulation involving millions of vessels. The feed hematocrit (Hct) is varied at the inlet of the coronary arterial tree, and the Fahraeus-Lindqvist effect and phase separation are considered throughout the vasculature. The major findings are as follows: 1) vessel compliance is the major determinant of nonlinearity of the pressure-flow relation, and 2) changes in Hct influence wall shear stress (WSS) in epicardial coronary arteries more significantly than in transmural and perfusion arterioles because of the Fahraeus-Lindqvist effect. The present study predicts the flow rate as a second-order polynomial function of inlet pressure due to vessel compliance. WSS in epicardial coronary arteries increases >15% with an increase of feed Hct from 45% to 60% and decreases >15% with a decrease of feed Hct from 45% to 30%, whereas WSS in small arterioles is not affected as feed Hct changes in this range. These findings have important implications for acute Hct changes under vasodilated conditions.
Three-dimensional measurement of alveolar airspace volumes in normal and emphysematous lungs using micro-CT
Authors: Parameswaran Harikrishnan , Bartolák-Suki Erzsébet , Hamakawa Hiroshi , Majumdar Arnab , Allen Philip G. , Suki Béla
Published: June 2009

In pulmonary emphysema, the alveolar structure progressively breaks down via a three-dimensional (3D) process that leads to airspace enlargement. The characterization of such structural changes has, however, been based on measurements from two-dimensional (2D) tissue sections or estimates of 3D structure from 2D measurements. In this study, we developed a novel silver staining method for visualizing tissue structure in 3D using micro-computed tomographic (CT) imaging, which showed that at 30 cmH20 fixing pressure, the mean alveolar airspace volume increased from 0.12 nl in normal mice to 0.44 nl and 2.14 nl in emphysematous mice, respectively, at 7 and 14 days following elastase-induced injury. We also assessed tissue structure in 2D using laser scanning confocal microscopy. The mean of the equivalent diameters of the alveolar airspaces was lower in 2D compared with 3D, while its variance was higher in 2D than in 3D in all groups. However, statistical comparisons of alveolar airspace size from normal and emphysematous mice yielded similar results in 2D and 3D: compared with control, both the mean and variance of the equivalent diameters increased by 7 days after treatment. These indexes further increased from day 7 to day 14 following treatment. During the first 7 days following treatment, the relative change in SD increased at a much faster rate compared with the relative change in mean equivalent diameter. We conclude that quantifying heterogeneity in structure can provide new insight into the pathogenesis or progression of emphysema that is enhanced by improved sensitivity using 3D measurements.
Initial orthostatic hypotension is unrelated to orthostatic tolerance in healthy young subjects
Authors: Thomas Kate N. , Cotter James D. , Galvin Sean D. , Williams Michael J. A. , Willie Chris K. , Ainslie Philip N.
Published: June 2009

The physiological challenge of standing upright is evidenced by temporary symptoms of light-headedness, dizziness, and nausea. It is not known, however, if initial orthostatic hypotension (IOH) and related symptoms associated with standing are related to the occurrence of syncope. Since IOH reflects immediate and temporary adjustments compared with the sustained adjustments during orthostatic stress, we anticipated that the severity of IOH would be unrelated to syncope. Following a standardized period of supine rest, healthy volunteers [ n = 46; 25 ± 5 yr old (mean ± SD)] were instructed to stand upright for 3 min, followed by 60° head-up tilt with lower-body negative pressure in 5-min increments of −10 mmHg, until presyncope. Beat-to-beat blood pressure (radial arterial or Finometer), middle cerebral artery blood velocity (MCAv), end-tidal Pco2, and cerebral oxygenation (near-infrared spectroscopy) were recorded continuously. At presyncope, although the reductions in mean arterial pressure, MCAv, and cerebral oxygenation were similar to those during IOH (40 ± 11 vs. 43 ± 12%; 36 ± 18 vs. 35 ± 13%; and 6 ± 5 vs. 4 ± 2%, respectively), the reduction in end-tidal CO2was greater (−7 ± 6 vs. −4 ± 3 mmHg) and was related to the decline in MCAv ( R2= 0.4; P < 0.05). While MCAv pulsatility was elevated with IOH, it was reduced at presyncope ( P < 0.05). The cardiorespiratory and cerebrovascular changes during IOH were unrelated to those at presyncope, and interestingly, there was no relationship between the hemodynamic changes and the incidence of subjective symptoms in either scenario. During IOH, the transient nature of physiological changes can be well tolerated; however, potentially mediated by a reduced MCAv pulsatility and greater degree of hypocapnic-induced cerebral vasoconstriction, when comparable changes are sustained, the development of syncope is imminent.
Accurate Prenatal Diagnosis of Hb Bart’s Hydrops Fetalis in Daily Practice with a Double-Check PCR System
Authors: Karnpean Rossarin , Fucharoen Goonnapa , Fucharoen Supan , Sae-ung Nattaya , Sanchaisuriya Kanokwan , Ratanasiri Thawalwong
Published: June 2009

Hemoglobin (Hb) Bart’s hydrops fetalis is a fatal condition associated with homozygous α⁰-thalassemia. Prenatal diagnosis of the disease is usually done by gap-PCR; however, misdiagnosis can occur with allelic dropout. Diagnosis using more than one method is preferred. We describe a double-check PCR assay for accurate prenatal diagnosis. The study was conducted on 64 fetuses at risk of homozygous α⁰-thalassemia encountered at our routine thalassemia diagnosis laboratory. Chorionic villus sample (CVS), amniotic fluid or fetal blood specimens were obtained from pregnant women at risk and analyzed by two PCR methods. In the first method, the SEA α⁰-thalassemia deletion of parents and fetuses were determined by gap-PCR routinely run in our laboratory. In another method, two specific fragments located 5′ to the ζ2 gene (XbaI fragment) and the α2-globin gene (RsaI fragment) together with the gap-PCR fragment were multiply co-amplified to determine the presence or absence of normal and α⁰-thalassemia alleles. The molecular diagnosis of α⁰-thalassemia was possible in all 64 fetuses using the two PCR approaches. The final diagnoses included 13 normal, 29 unaffected heterozygote and 22 homozygote α⁰-thalassemia fetuses.The two PCR assays disclosed no discordant result in the diagnosis of the Hb Bart’s hydrops fetalis caused by α⁰-thalassemia.The combined PCR assay for gap-PCR, ζ2 XbaI and α2 RsaI fragments, described here, is simple, accurate and applicable in the prenatal diagnosis of Hb Bart’s hydrops fetalis in a routine setting.
Radiological versus Histopathological Diagnosis of Usual Interstitial Pneumonia in the Clinical Practice: Does It Have Any Survival Difference?
Authors: Quadrelli Silvia , Molinari Luciana , Ciallella Lorena , Spina Juan Carlos , Sobrino Edgardo , Chertcoff Julio
Published: June 2009

Background: Recent studies have shown that quantification of specific histopathologic features found in usual interstitial pneumonia (UIP) are useful in defining a prognosis, suggesting the need of biopsy in all patients. Objectives: This study examines whether UIP-associated mortality is different in patients diagnosed by high-resolution computed tomography (HRCT) features considered definite of UIP and in patients with no definite radiological diagnosis that required histological confirmation of diagnoses. Methods: Forty-five patients were included (30 males, mean age 65.3 ± 10.7 years). Two groups of patients were identified: those with HRCT findings of definite UIP (n = 26) and those whose radiological diagnosis was not definite and required a surgical biopsy to confirm the presence of UIP (n = 19). Forced vital capacity, forced expiratory volume in 1 s and diffusing capacity for carbon monoxide were measured in all patients. All data were obtained from medical records, and the survival status was obtained by telephone or personal interview. All clinical parameters and HRCTs were obtained within 1 month before surgical lung biopsy. Results: Median survival was not different across groups and was similar to that previously reported (35 months). Kaplan-Meier analysis did not show any difference in 5-year survival between both groups. Conclusions: In a clinical context in which the diagnosis of UIP can be obtained as a dynamic process that includes an integrated clinical, radiological and pathologic approach, a reliable diagnosis of UIP can be obtained based on a typical definite HRCT with no risk of including patients with a more benign disease and a more prolonged survival.
Toll-Like Receptor 2-Independent and MyD88-Dependent Gene Expression in the Mouse Brain
Authors: Naert Gaëlle , Laflamme Nathalie , Rivest Serge
Published: June 2009

Toll-like receptors (TLRs) are essential to mount a rapid innate immune reaction to pathogens. Although TLR2 is the key receptor for pathogen-associated molecular patterns from Gram-positive bacteria, a robust transcriptional activation of the gene encoding this receptor takes place in the brain of mice exposed to the TLR4 ligand lipopolysaccharide (LPS). TLR2 gene expression is actually used as a reliable marker of activated microglia in vivo, but its functions remain unknown. The present study investigated the role of this receptor in mediating LPS-induced gene expression in the mouse brain. Immune genes were measured using both in situ hybridization and real time RT-PCR. Despite the robust microglial TLR2 expression, this receptor does not modulate transcriptional activity by TLR4 signaling. TLR2-deficient mice and their wild-type littermates had similar IκBα mRNA levels and induction of innate immune genes from 6 h to 10 days after LPS injection. In contrast, NF-κB activity, cytokine, chemokine, TLR2 and CD14 transcripts were no longer detected in MyD88-deficient mice. Indeed, the hybridization signal for most of the transcripts measured in this study was similar in the brain of MyD88–/– mice exposed to either saline or LPS. These data indicate that while TLR2 transcription is dependent on MyD88 signaling in microglia, this innate immune receptor is not involved in the immune response to LPS. On the other hand, MyD88 pathway is essential for the endotoxin to induce expression of immune genes in the central nervous system.