bluuebunny/crossref_metadata_2025 huggingface dataset:
Pasteurella multocida
Expresses Two Lipopolysaccharide Glycoforms Simultaneously, but Only a Single Form Is Required for Virulence: Identification of Two Acceptor-Specific Heptosyl I Transferases
Authors: Harper Marina , Boyce John D. , Cox Andrew D. , St. Michael Frank , Wilkie Ian W. , Blackall P. J. , Adler Ben
Published: May 2007

Lipopolysaccharide (LPS) is a critical virulence determinant in
Pasteurella multocida
and a major antigen responsible for host protective immunity. In other mucosal pathogens, variation in LPS or lipooligosaccharide structure typically occurs in the outer core oligosaccharide regions due to phase variation.
P. multocida
elaborates a conserved oligosaccharide extension attached to two different, simultaneously expressed inner core structures, one containing a single phosphorylated 3-deoxy-
d
-manno-octulosonic acid (Kdo) residue and the other containing two Kdo residues. We demonstrate that two heptosyltransferases, HptA and HptB, add the first heptose molecule to the Kdo
1
residue and that each exclusively recognizes different acceptor molecules. HptA is specific for the glycoform containing a single, phosphorylated Kdo residue (glycoform A), while HptB is specific for the glycoform containing two Kdo residues (glycoform B). In addition, KdkA was identified as a Kdo kinase, required for phosphorylation of the first Kdo molecule. Importantly, virulence data obtained from infected chickens showed that while wild-type
P. multocida
expresses both LPS glycoforms in vivo, bacterial mutants that produced only glycoform B were fully virulent, demonstrating for the first time that expression of a single LPS form is sufficient for
P. multocida
survival in vivo. We conclude that the ability of
P. multocida
to elaborate alternative inner core LPS structures is due to the simultaneous expression of two different heptosyltransferases that add the first heptose residue to the nascent LPS molecule and to the expression of both a bifunctional Kdo transferase and a Kdo kinase, which results in the initial assembly of two inner core structures.
Biofilms Protect
Mycoplasma pulmonis
Cells from Lytic Effects of Complement and Gramicidin
Authors: Simmons Warren L. , Dybvig Kevin
Published: May 2007

The length of the tandem repeat region of the Vsa protein of
Mycoplasma pulmonis
has previously been shown to modulate the susceptibility of mycoplasmas to killing by complement: cells that produce a short form of the Vsa protein are highly sensitive, and cells producing the long Vsa protein are resistant. In contrast to their differing susceptibilities to complement, the mycoplasmas were highly sensitive to gramicidin irrespective of the length of the Vsa protein produced. We show here that when encased within a biofilm, cells of
M. pulmonis
producing a short form of the Vsa protein were more resistant to complement and gramicidin than mycoplasmas that were dispersed. The resistance appeared to be localized to those mycoplasmas within tower structures of the biofilms. Biofilm formation may be a mechanism that protects mycoplasmas from host immunity.
Cytokines, Signaling Pathways, and Effector Molecules Required for the Control ofLeishmania(Viannia)braziliensisin Mice
Authors: Rocha F. Janaina Soares , Schleicher Ulrike , Mattner Jochen , Alber Gottfried , Bogdan Christian
Published: May 2007

Cutaneous leishmaniasis is caused by protozoan parasites of the genusLeishmania. The mechanisms of pathogen control have been established primarily in the mouse model ofLeishmania majorinfection, but they might not hold true for otherLeishmaniaspecies associated with cutaneous disease. Here, we analyzed the role of cytokines, signaling components, and effector molecules in the control of New World cutaneous leishmaniasis due toL. braziliensis. UnlikeL. major,L. braziliensiscaused small, nonulcerative, and self-healing skin swelling in C57BL/6 mice, as well as BALB/c mice. In contrast to the results obtained forL. mexicana, mice deficient for interleukin-12 or its key signaling molecule, signal transducer and activator of transcription 4, rapidly succumbed to severe visceral leishmaniasis. Infection of tumor necrosis factor knockout mice withL. braziliensisled to progressive, nonhealing skin lesions with erosions and hemorrhagic ulcerations, but in contrast to the results withL. major, only 20 to 30% of the mice developed fatal visceral disease. As seen withL. major, mice with a deleted inducible nitric oxide synthase gene (iNOS−/−) were unable to containL. braziliensisin the skin, whereas the control of the parasite in the spleen remained unimpaired. Unlike what happens inL. majorinfections, NADPH oxidase had no impact on the course of disease inL. braziliensis-infected mice. These results not only define essential components of a protective immune response toL. braziliensisbut also illustrate that the requirements for the control of cutaneous leishmaniasis vary between different parasite species.
Cytolysin-Dependent Escape of the Bacterium from the Phagosome Is Required but Not Sufficient for Induction of the Th1 Immune Response againstListeria monocytogenesInfection: Distinct Role of Listeriolysin O Determined by Cytolysin Gene Replacement
Authors: Hara Hideki , Kawamura Ikuo , Nomura Takamasa , Tominaga Takanari , Tsuchiya Kohsuke , Mitsuyama Masao
Published: May 2007

Listeria monocytogenesevades the antimicrobial mechanisms of macrophages by escaping from the phagosome into the cytosolic space via a unique cytolysin that targets the phagosomal membrane, listeriolysin O (LLO), encoded byhly. Gamma interferon (IFN-γ), which is known to play a pivotal role in the induction of Th1-dependent protective immunity in mice, appears to be produced, depending on the bacterial virulence factor. To determine whether the LLO molecule (the major virulence factor ofL. monocytogenes) is indispensable or the escape of bacteria from the phagosome is sufficient to induce IFN-γ production, we first constructed anhly-deleted mutant ofL. monocytogenesand then established isogenicL. monocytogenesmutants expressing LLO or ivanolysin O (ILO), encoded byilofromListeria ivanovii. LLO-expressingL. monocytogeneswas highly capable of inducing IFN-γ production andListeria-specific protective immunity, while thehly-deleted mutant was not. In contrast, the level of IFN-γ induced by ILO-expressingL. monocytogeneswas significantly lower both in vitro and in vivo, despite the ability of this strain to escape the phagosome and the intracellular multiplication at a level equivalent to that of LLO-expressingL. monocytogenes. Only a negligible level of protective immunity was induced in mice against challenge with LLO- and ILO-expressingL. monocytogenes. These results clearly show that escape of the bacterium from the phagosome is a prerequisite but is not sufficient for the IFN-γ-dependent Th1 response againstL. monocytogenes, and some distinct molecular nature of LLO is indispensable for the final induction of IFN-γ that is essentially required to generate a Th1-dependent immune response.
Recovery of cognitive and dynamic motor function following concussion
Authors: Parker Tonya M , Osternig Louis R , van Donkelaar Paul , Chou Li-Shan
Published: May 2007

Objective:

Neuropsychological testing has been advocated as an important tool of proper post-concussion management. Although these measures provide information that can be used in the decision of when to return an individual to previous levels of physical activity, they provide little data on motor performance following injury. The purpose of this investigation was to examine the relationship between measures of dynamic motor performance and neuropsychological function following concussion over the course of 28 days.

Methods:

Participants completed two experimental protocols: gait stability and neuropsychological testing. The gait stability protocol measured whole-body centre of mass motion as subjects walked under conditions of divided and undivided attention. Neuropsychological testing consisted of a computerised battery of tests designed to assess memory, reaction time, processing speed and concussion symptoms. Correlation coefficients were computed between all neuropsychological and gait variables and comparisons of neuropsychological and gait stability post-concussion recovery curves were assessed.

Results:

Dynamic motor tasks, such as walking under varying conditions of attention, are complex and demanding undertakings, which require a longer recovery time following a concussion than cognitive measures. Little statistical relationship was found between the neuropsychological and gait variables, and the recovery curves of neuropsychological and gait domains were observed to be independent.

Conclusions:

In order to fully examine the effects of concussion and determine the optimal time for a safe return to activity, a multi-factorial approach, including both cognitive and motor tasks, should be employed.
PROPERTIES AND STRUCTURE OF Ag-DOPED As2Se3 GLASSES
Authors: ZHA CONGJI , SMITH ANITA , PRASAD AMRITA , WANG RONGPING , MADDEN STEVE , LUTHER-DAVIES BARRY
Published: May 2007

Ag -doped As 2 Se 3 glasses were prepared by the melt-quenching method and the influence of silver doping on the glass structure and optical properties was studied using Raman and UV-Vis-IR spectroscopy and differential scanning calorimetry. For Ag concentrations less than 15 at%, introduction of Ag into As 2 Se 3 glasses mainly leads to the formation of Ag-Se covalent bonds, resulting in destruction of the glass network. This manifests itself by a decrease in the glass transition temperature and low frequency shifts in the As-Se Raman band. When the Ag concentration was higher than 25 at%, some Ag atoms exist in the glass matrix as coordinative bonds, resulting in a slight increase in the glass transition temperature and high frequency shifts in the Raman peaks. The relationship between the glass structure and properties is discussed.
THE INVESTIGATION OF ELECTRONIC PROPERTIES AND MICROSCOPIC SECOND-ORDER NONLINEAR OPTICAL BEHAVIOR OF 1-SALICYLIDENE-3-THIO-SEMICARBAZONE
Authors: KARAKAS ASLI , UNVER HUSEYIN , ELMALI AYHAN
Published: May 2007

To investigate the microscopic second-order nonlinear optical (NLO) behavior of the 1-salicylidene-3-thio-semicarbazone Schiff base compound, the electric dipole moments (μ), linear static polarizabilities (α) and first static hyperpolarizabilites (β) have been calculated using finite field second-order Møller-Plesset perturbation (FF MP2) theory. The ab-initio results on (hyper)polarizabilities show that the investigated molecule might have microscopic NLO properties with non-zero values. To understand the NLO behavior in the context of molecular orbital structure, we have also examined the highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO) and the HOMO-LUMO gap in the same theoretical framework as the (hyper)polarizability calculations. In addition to the NLO properties, the electronic transition spectra have been computed using a semi-empirical method (ZINDO). ZINDO calculation results show that the electronic transition wavelengths have been estimated to be shorter than 400 nm.
PROPAGATION OF SINGULARITIES FOR SEMI-LINEAR WAVE EQUATIONS WITH NONLINEARITY SATISFYING THE NULL CONDITION
Authors: ITO SHINGO
Published: May 2007

We study the propagation of singularities for semi-linear wave equations □u = F(u, Du) satisfying the null condition, and improve an earlier result of ours. Microlocal Sobolev regularity in [Formula: see text] propagates along null bicharacteristics, when a suitable condition is imposed on s and r. We provide here optimal conditions on s and r, and improve existing results to include values up to n/2 < s ≦ r < 3s - n when the nonlinearity F(u, Du) satisfies the null condition.
ON THE GLOBAL EXISTENCE OF ROUGH SOLUTIONS OF THE CUBIC DEFOCUSING SCHRÖDINGER EQUATION IN R2 + 1
Authors: FANG Y. F. , GRILLAKIS MANOUSSOS G.
Published: May 2007

We consider the cubic defocusing Schrödinger equation in two space dimensions and prove that if the initial data are in H1/2, then there exists a global solution in time. The proof combines the argument from [5] with some new correlation estimates for the Schrödinger equation.
Metabolic challenges reveal impaired fatty acid metabolism and translocation of FAT/CD36 but not FABPpm in obese Zucker rat muscle
Authors: Han Xiao-Xia , Chabowski Adrian , Tandon Narendra N. , Calles-Escandon Jorge , Glatz Jan F. C. , Luiken Joost J. F. P. , Bonen Arend
Published: May 2007

We examined, in muscle of lean and obese Zucker rats, basal, insulin-induced, and contraction-induced fatty acid transporter translocation and fatty acid uptake, esterification, and oxidation. In lean rats, insulin and contraction induced the translocation of the fatty acid transporter FAT/CD36 (43 and 41%, respectively) and plasma membrane-associated fatty acid binding protein (FABPpm; 19 and 60%) and increased fatty acid uptake (63 and 40%, respectively). Insulin and contraction increased lean muscle palmitate esterification and oxidation 72 and 61%, respectively. In obese rat muscle, basal levels of sarcolemmal FAT/CD36 (+33%) and FABPpm (+14%) and fatty acid uptake (+30%) and esterification (+32%) were increased, whereas fatty acid oxidation was reduced (−28%). Insulin stimulation of obese rat muscle increased plasmalemmal FABPpm (+15%) but not plasmalemmal FAT/CD36, blunted fatty acid uptake and esterification, and failed to reduce fatty acid oxidation. In contracting obese rat muscle, the increases in fatty acid uptake and esterification and FABPpm translocation were normal, but FAT/CD36 translocation was impaired and fatty acid oxidation was blunted. There was no relationship between plasmalemmal fatty acid transporters and palmitate partitioning. In conclusion, fatty acid metabolism is impaired at several levels in muscles of obese Zucker rats; specifically, they are 1) insulin resistant with respect to FAT/CD36 translocation and fatty acid uptake, esterification, and oxidation and 2) contraction resistant with respect to fatty acid oxidation and FAT/CD36 translocation, but, conversely, 3) obese muscles are neither insulin nor contraction resistant at the level of FABPpm. Finally, 4) there is no evidence that plasmalemmal fatty acid transporters contribute to the channeling of fatty acids to specific metabolic destinations within the muscle.
Sodium Currents in Mesencephalic Trigeminal Neurons From Nav1.6 Null Mice
Authors: Enomoto Akifumi , Han Juliette M. , Hsiao Chie-Fang , Chandler Scott H.
Published: May 2007

Previous studies using pharmacological methods suggest that subthreshold sodium currents are critical for rhythmical burst generation in mesencephalic trigeminal neurons (Mes V). In this study, we characterized transient ( INaT), persistent ( INaP), and resurgent ( Ires) sodium currents in Nav1.6-null mice ( med mouse, Nav1.6−/−) lacking expression of the sodium channel gene Scn8a. We found that peak transient, persistent, and resurgent sodium currents from med (Nav1.6−/−) mice were reduced by 18, 39, and 76% relative to their wild-type (Nav1.6+/+) littermates, respectively. Current clamp recordings indicated that, in response to sinusoidal constant amplitude current (ZAP function), all neurons exhibited membrane resonance. However, Mes V neurons from med mice had reduced peak amplitudes in the impedance-frequency relationship (resonant Q-value) and attenuated subthreshold oscillations despite the similar passive membrane properties compared with wild-type littermates. The spike frequency-current relationship exhibited reduced instantaneous discharge frequencies and spike block at low stimulus currents and seldom showed maintained spike discharge throughout the stimulus in the majority of med neurons compared with wild-type neurons. Importantly, med neurons never exhibited maintained stimulus-induced rhythmical burst discharge unlike those of wild-type littermates. The data showed that subthreshold sodium currents are critical determinants of Mes V electrogenesis and burst generation and suggest a role for resurgent sodium currents in control of spike discharge.
CETP genotypes and HDL-cholesterol phenotypes in the HERITAGE Family Study
Authors: Spielmann Nadine , Leon Arthur S. , Rao D. C. , Rice Treva , Skinner James S. , Bouchard Claude , Rankinen Tuomo
Published: May 2007

Associations between cholesteryl ester transfer protein (CETP) polymorphisms and high-density lipoprotein cholesterol (HDL-c) levels before and after 20 wk of endurance training were investigated in the HERITAGE Family Study. Plasma HDL-c, HDL2-c, HDL3-c, and apolipoprotein (apo)A1 levels were measured, and 13 CETP single nucleotide polymorphisms (SNPs) were genotyped in 265 blacks and 486 whites. Three haplotypes defined by SNPs at the −1337, −971, and −629 sites were strongly associated with baseline HDL-c levels in whites. Both C−1337T and C−629A were associated with baseline HDL-c ( P < 0.001) and apoA1 ( P < 0.01) when tested separately. However, only C−629A remained significant in a combined model. G−971A was not associated with HDL phenotypes, but showed significant interactions with C−629A ( P = 0.002) on baseline traits. Genotype-by-sex interactions were observed at the −629 locus for HDL3-c ( P = 0.004) and apoA1 ( P = 0.02) training responses in whites. In women, the −629 A/A homozygotes showed greater increases in HDL3-c ( P = 0.02) and apoA1 ( P = 0.02) levels than the other genotypes. Finally, apolipoprotein E (APOE) genotype and the CETP C−629A locus contributed independently and in additive fashion to the HDL traits, explaining 6.0–8.8% of the variance. The CETP −1337T and −629A alleles are associated with higher baseline HDL-c and apoA1 levels. The beneficial effects of endurance training on plasma HDL3-c and apoA1 levels are evident in white women homozygous for the −629A allele. The CETP and APOE genotypes account for up to 9% of the variance in HDL-c phenotypes in the HERITAGE Family Study.
Relationship Between Blood Pressure and Stroke Recurrence in Patients With Intracranial Arterial Stenosis
Authors: Turan Tanya N. , Cotsonis George , Lynn Michael J. , Chaturvedi Seemant , Chimowitz Marc
Published: May 2007

Background—

Many clinicians allow blood pressure to run high in patients with intracranial stenosis to protect against hypoperfusion. We sought to determine whether higher blood pressure decreases the risk of stroke in these patients.

Methods and Results—

Data on 567 patients in the Warfarin-Aspirin Symptomatic Intracranial Disease (WASID) trial were analyzed. Time to ischemic stroke and stroke in the same territory of the stenotic vessel was compared in patients grouped by mean systolic blood pressure (SBP) and mean diastolic blood pressure (DBP) during the study. Additional analyses were based on severity and location of stenosis. Ischemic stroke risk increased with increasing mean SBP and DBP on univariate analysis (
P
<0.0001,
P
<0.0001) and after adjustment for risk factors (
P
=0.0008,
P
<0.0001). Elevated mean SBP and DBP also resulted in increased risk of stroke in the territory in univariate (
P
=0.0065,
P
<0.0001) and adjusted (
P
=0.0002,
P
=0.0005) analyses. The increased risk of stroke with increasing SBP was driven largely by patients in the highest SBP group. Patients with moderate (<70%) stenosis had increased risk of stroke (
P
<0.0001,
P
=0.003) and stroke in the territory (
P
=0.0002,
P
=0.010) with increased SBP and DBP. Patients with severe (≥70%) stenosis had increased risk of stroke and stroke in the territory with elevated DBP (
P
=0.004,
P
=0.004).

Conclusions—

In patients with intracranial stenosis, higher blood pressure is associated with increased (not decreased) risk of ischemic stroke and stroke in the territory of the stenotic vessel. These findings argue strongly against the common clinical practice of maintaining high blood pressure in patients with intracranial stenosis.
Receptor for Activated C-Kinase 1, a Novel Interaction Partner of Type II Bone Morphogenetic Protein Receptor, Regulates Smooth Muscle Cell Proliferation in Pulmonary Arterial Hypertension
Authors: Zakrzewicz Anna , Hecker Matthias , Marsh Leigh M. , Kwapiszewska Grazyna , Nejman Bozena , Long Lu , Seeger Werner , Schermuly Ralph T. , Morrell Nicholas W. , Morty Rory E. , Eickelberg Oliver
Published: May 2007

Background—

Pulmonary arterial hypertension (PAH) is characterized by selective elevation of pulmonary arterial pressure. The pathological hallmark of PAH is the narrowing of pulmonary arterioles secondary to endothelial cell dysfunction and smooth muscle cell proliferation. Heterozygous mutations in
BMPR2
, encoding the type II bone morphogenetic protein receptor (BMPRII), were identified in PAH, suggesting that alterations to BMPRII function are involved in disease onset and/or progression.

Methods and Results—

We identified the receptor for activated C-kinase (RACK1) as a novel interaction partner of BMPRII by yeast 2-hybrid analyses using the kinase domain of BMPRII as a bait. Glutathione-S-transferase pull-down and coimmunoprecipitation confirmed the interaction of RACK1 with BMPRII in vitro and in vivo. RACK1–BMPRII interaction was reduced when kinase domain mutations occurring in patients with PAH were introduced to BMPRII. Immunohistochemistry of lung sections from PAH and control patients and immunofluorescence analysis of primary pulmonary arterial smooth muscle cells demonstrated colocalization of BMPRII and RACK1 in vivo. Quantitative reverse-transcription polymerase chain reaction and Western blot analysis showed significant downregulation of RACK1 expression in the rat model of monocrotaline-induced PAH but not in pulmonary arterial smooth muscle cells from PAH patients. Abrogation of RACK1 expression in pulmonary arterial smooth muscle cells led to decreased Smad1 phosphorylation and increased proliferation, whereas overexpression of RACK1 led to increased Smad1 phosphorylation and decreased proliferation.

Conclusions—

RACK1, a novel interaction partner of BMPRII, constitutes a new negative regulator of pulmonary arterial smooth muscle cell proliferation, suggesting a potential role for RACK1 in the pathogenesis of PAH.
Genetic and Shared Environmental Factors Do Not Confound the Association Between Birth Weight and Hypertension
Authors: Bergvall Niklas , Iliadou Anastasia , Johansson Stefan , de Faire Ulf , Kramer Michael S. , Pawitan Yudi , Pedersen Nancy L. , Lichtenstein Paul , Cnattingius Sven
Published: May 2007

Background—

Studies have found associations between low birth weight and increased risks of cardiovascular diseases in adulthood. However, these associations could be due to confounding by genetic or socioeconomic factors.

Methods and Results—

We performed a study on Swedish like-sexed twins with known zygosity who were born from 1926 to 1958. First, to obtain an overall effect of birth weight on risk of hypertension, we performed cohort analyses on all twins (n=16 265). Second, to address genetic and shared environmental confounding, we performed a nested co-twin control analysis within 594 dizygotic and 250 monozygotic twin pairs discordant for hypertension. Birth characteristics, including birth weight, were obtained from original birth records. Information from adulthood was collected from a postal questionnaire in 1973 (body mass index, height, smoking, and alcohol use) and from a telephone interview conducted from 1998 to 2002 (hypertension and socioeconomic status). Hypertension was defined as reporting both high blood pressure and treatment with antihypertensive medication. In the cohort analysis, the adjusted odds ratio for hypertension in relation to a 500-g decrease in birth weight was 1.42 (95% confidence interval, 1.25 to 1.61). In the co-twin control analyses, the corresponding odds ratios were 1.34 (95% confidence interval, 1.07 to 1.69) for dizygotic and 1.74 (95% confidence interval, 1.13 to 2.70) for monozygotic twins.

Conclusions—

In the largest twin study on the fetal origins of hypertension, we found that decreased birth weight is associated with increased risk of hypertension independently of genetic factors, shared familial environment, and risk factors for hypertension in adulthood, including body mass index.
Outcomes and Optimal Antithrombotic Therapy in Women Undergoing Fibrinolysis for ST-Elevation Myocardial Infarction
Authors: Mega Jessica L. , Morrow David A. , Östör Erika , Dorobantu Maria , Qin Jie , Antman Elliott M. , Braunwald Eugene
Published: May 2007

Background—

The manifestations, complications, and outcomes of cardiovascular disease differ between women and men. The safety and efficacy of pharmacological reperfusion therapy in women with ST-elevation myocardial infarction are of particular interest.

Methods and Results—

We investigated outcomes in the Enoxaparin and Thrombolysis Reperfusion for Acute Myocardial Infarction Treatment–Thrombolysis in Myocardial Infarction (ExTRACT-TIMI) 25 study, which randomized ST-elevation myocardial infarction patients with planned fibrinolysis to enoxaparin or unfractionated heparin. Compared with men (n=15 696), women (n=4783) were older and more likely to have hypertension and diabetes (
P
<0.001). The unadjusted 30-day mortality rate for women was >2-fold higher than for men (13.2% versus 5.4%; odds ratio, 2.66; 95% CI, 2.40 to 2.96). After adjustment for age, fibrinolytic therapy, revascularization, region, and elements of the TIMI Risk Score, women had a 1.25-fold-higher 30-day risk of death (95% CI, 1.08 to 1.46) but similar risk of intracerebral hemorrhage (adjusted odds ratio, 0.81; 95% CI, 0.52 to 1.26). The 30-day rate of death or nonfatal MI in women was reduced by enoxaparin compared with unfractionated heparin in women (15.4% versus 18.3%;
P
=0.007). Major bleeding was more frequent in women receiving enoxaparin compared with those receiving unfractionated heparin (2.3% versus 1.4%;
P
=0.022) but similar among women and men receiving enoxaparin (2.3% versus 2.0%;
P
=0.39). The rates of death, nonfatal myocardial infarction, or nonfatal major bleeding (net clinical benefit) were lower with enoxaparin (absolute risk reduction, 2.6% in women [
P
=0.02] and 1.6% in men [
P
=0.001]).

Conclusions—

In ExTRACT-TIMI 25, women presented with a profile of higher baseline risk and increased short-term mortality. In this large, contemporary clinical trial, women had similar relative and greater absolute risk reductions than men when treated with enoxaparin compared with unfractionated heparin as adjunctive therapy with fibrinolysis.
Guidelines for the Early Management of Adults With Ischemic Stroke
Authors: Adams Harold P. , del Zoppo Gregory , Alberts Mark J. , Bhatt Deepak L. , Brass Lawrence , Furlan Anthony , Grubb Robert L. , Higashida Randall T. , Jauch Edward C. , Kidwell Chelsea , Lyden Patrick D. , Morgenstern Lewis B. , Qureshi Adnan I. , Rosenwasser Robert H. , Scott Phillip A. , Wijdicks Eelco F.M.
Published: May 2007

Purpose—

Our goal is to provide an overview of the current evidence about components of the evaluation and treatment of adults with acute ischemic stroke. The intended audience is physicians and other emergency healthcare providers who treat patients within the first 48 hours after stroke. In addition, information for healthcare policy makers is included.

Methods—

Members of the panel were appointed by the American Heart Association Stroke Council’s Scientific Statement Oversight Committee and represented different areas of expertise. The panel reviewed the relevant literature with an emphasis on reports published since 2003 and used the American Heart Association Stroke Council’s Levels of Evidence grading algorithm to rate the evidence and to make recommendations. After approval of the statement by the panel, it underwent peer review and approval by the American Heart Association Science Advisory and Coordinating Committee. It is intended that this guideline be fully updated in 3 years.

Results—

Management of patients with acute ischemic stroke remains multifaceted and includes several aspects of care that have not been tested in clinical trials. This statement includes recommendations for management from the first contact by emergency medical services personnel through initial admission to the hospital. Intravenous administration of recombinant tissue plasminogen activator remains the most beneficial proven intervention for emergency treatment of stroke. Several interventions, including intra-arterial administration of thrombolytic agents and mechanical interventions, show promise. Because many of the recommendations are based on limited data, additional research on treatment of acute ischemic stroke is needed.
Regulation of Renin Secretion and Expression in Mice Deficient in β1- and β2-Adrenergic Receptors
Authors: Kim Soo Mi , Chen Limeng , Faulhaber-Walter Robert , Oppermann Mona , Huang Yuning , Mizel Diane , Briggs Josephine P. , Schnermann Jurgen
Published: May 2007

The present experiments were performed in β1/β2-adrenergic receptor–deficient mice (β1/β2ADR
−/−
) to assess the role of β-adrenergic receptors in basal and regulated renin expression and release. On a control diet, plasma renin concentration (in ng angiotensin I per mL per hour), determined in tail vein blood, was significantly lower in β1/β2ADR
−/−
than in wild-type (WT) mice (222±65 versus 1456±335;
P
<0.01). Renin content and mRNA were 77% and 65±5% of WT. Plasma aldosterone (in picograms per mL) was also significantly reduced (420±36 in β1/β2ADR
−/−
versus 692±59 in WT). A low-salt diet (0.03%) for 1 week increased plasma renin concentration significantly in both β1/β2ADR
−/−
and WT mice (to 733±54 and 2789±555), whereas a high-salt diet (8%) suppressed it in both genotypes (to 85±24 in β1/β2ADR
−/−
and to 676±213 in WT). The absolute magnitude of salt-induced changes of plasma renin concentration was markedly greater in WT mice. Acute stimulation of renin release by furosemide, quinaprilat, captopril, or candesartan caused significant increases of plasma renin concentration in both β1/β2ADR
−/−
and WT mice, but again the absolute changes were greater in WT mice. We conclude that maintenance of normal levels of renin synthesis and release requires tonic β-adrenergic receptor activation. In the chronic absence of β-adrenergic receptor input, the size of the releasable renin pool decreases with a concomitant reduction in the magnitude of the plasma renin concentration changes caused by variations of salt intake or acute stimulation with furosemide, angiotensin-converting enzyme, or angiotensin type 1 receptor inhibition, but regulatory responsiveness is nonetheless maintained.
Norepinephrine Transporter Blockade With Atomoxetine Induces Hypertension in Patients With Impaired Autonomic Function
Authors: Shibao Cyndya , Raj Satish R. , Gamboa Alfredo , Diedrich André , Choi Leena , Black Bonnie K. , Robertson David , Biaggioni Italo
Published: May 2007

Atomoxetine, a selective norepinephrine transporter blocker, could increase blood pressure by elevating norepinephrine concentration in peripheral sympathetic neurons. This effect may be masked in healthy subjects by central sympatholytic mechanisms. To test this hypothesis we studied the pressor effect of 18 mg of atomoxetine (pediatric dose) in 21 patients with damage of the central (10 subjects) and peripheral (11 subjects) autonomic nervous system. Atomoxetine was administered in a randomized, crossover, placebo-controlled fashion, and blood pressure and heart rate were measured at baseline and for 60 minutes after drug intake. Atomoxetine acutely increased seated and standing systolic blood pressure in patients with central autonomic failure by 54±26 (mean±standard deviation;
P
=0.004) and 45±23 mm Hg (
P
=0.016), respectively, as compared with placebo. At the end of the observation period the mean seated systolic blood pressure in the atomoxetine group was in the hypertensive range (149±26, range 113 to 209 mm Hg). However, in patients with peripheral autonomic failure, atomoxetine did not elicit a pressor response; seated and standing systolic blood pressure increased by 4±18 mm Hg (
P
=0.695) and 0.6±8 mm Hg (
P
=0.546) with atomoxetine as compared with placebo. In conclusion, atomoxetine induces a dramatic increase in blood pressure in patients with central autonomic failure even at very low doses. These findings suggest that a functional central sympatholytic pathway is essential to avoid hypertension in patients treated with this drug. Caution should be exercised when this medication is used in patients with milder form of autonomic impairment.
Acarbose, an α-Glucosidase Inhibitor, Attenuates Postprandial Hypotension in Autonomic Failure
Authors: Shibao Cyndya , Gamboa Alfredo , Diedrich Andre , Dossett Cynthia , Choi Leena , Farley Ginnie , Biaggioni Italo
Published: May 2007

Postprandial hypotension is an important clinical condition that predisposes to syncope, falls, angina, and cerebrovascular events. The magnitude of the fall in blood pressure after meals depends on enteric glucose availability. We hypothesized that acarbose, an α-glucosidase inhibitor that decreases glucose absorption in the small intestine, would attenuate postprandial hypotension. Acarbose or placebo was given 20 minutes before a standardized meal in 13 patients with postprandial hypotension in the setting of autonomic failure (age: 65±2.64 years; body mass index: 25±1.08 kg/m
2
; supine plasma norepinephrine: 110±26.6 pg/mL). Four patients were studied in a single-blind protocol and 9 patients in a double-blind, randomized, crossover fashion. Patients were studied supine, and blood pressure, heart rate, and neuroendocrine parameters were obtained at baseline and for 90 minutes after meal intake. After adjusting for potential confounders, acarbose significantly attenuated the postprandial fall in systolic and diastolic blood pressures by 17 mm Hg (95% CI: 7 to 28;
P
=0.003) and 9 mm Hg (95% CI: 5 to 14;
P
=0.001), respectively. Furthermore, acarbose effectively reduced plasma levels of insulin, a known vasodilator, by 11 μU/mL (95% CI: 5 to 18;
P
=0.001) compared with placebo. After adjusting for insulin levels, the attenuation of postprandial hypotension by acarbose remained significant, indicating that additional mechanisms contribute to this effect. In conclusion, 100 mg of acarbose successfully improved postprandial hypotension in patients with severe autonomic failure. This effect is not explained solely by a reduction in insulin levels.
Trended Cosinor Change Model for Analyzing Hemodynamic Rhythm Patterns in Hemodialysis Patients
Authors: Kelley Ken , Light Robert P. , Agarwal Rajiv
Published: May 2007

To describe circadian blood pressure (BP) patterns and linear interdialytic changes, a model was developed to describe simultaneously both the straight line change and oscillatory variation in BP and heart rate over an interdialytic interval in hemodialysis patients. Using this trended cosinor model, we simultaneously compared the impact of mean level of BP, linear changes over the interdialytic interval, and oscillatory changes in BP and its relationship with antihypertensive drug use. Neither a straight-line change model nor the cosinor model adequately described the BP variability in 12 750 BP measurements from 136 chronic stable hemodialysis patients. A combination of the 2 models that allowed for the oscillatory rhythmic pattern in BP variation to have an upward trend in the interdialytic period most accurately described the data. Time elapsed since the end of dialysis demonstrated a better model fit compared with the less meaningful clock time. More antihypertensive medication use was associated with increasing mean systolic, diastolic, and pulse pressure. Although the rate of change was blunted with increasing antihypertensive drug use, the impact on oscillatory change was U-shaped for systolic BP, direct for diastolic BP, and inverse for pulse pressure. A trended cosinor model better describes the change in BP in the interdialytic interval in hemodialysis patients, especially when time elapsed is measured from the end of dialysis. Antihypertensive drugs, though associated with higher average BP, are associated with blunted rate of change in BP over time.
Male control of copulation duration in a wolf spider (Araneae, Lycosidae)
Authors: Rypstra Ann , Wilder Shawn
Published: May 2007

While a great deal of research has examined mate choice, variation in behavior during copulation can also have important consequences for the fitness of males and females. We examined the relationships between male and female characteristics (age, size and condition) and copulation duration in the wolf spider

Hogna helluo

(Araneae, Lycosidae). In addition, we used these relationships to test if males control copulation duration. In this species, males mount the dorsal surface of females and females make no visible attempts to terminate mating. Male age was positively related to the duration of copulation. In addition, male condition was negatively related to the duration of copulation such that poor condition males mated for longer durations. If a group of outlier copulations are removed from the analysis, then male age is no longer a predictor of mating duration but male condition becomes an even stronger predictor of mating duration. Males that engaged in long copulations were more likely to be cannibalized following mating. Our data provide support for the hypothesis that males exert the primary influence on copulation duration in

H. helluo

. Older and poor condition males may engage in longer copulations to increase their paternity with the current female because they may have a lower chance of escaping postcopulatory sexual cannibalism or surviving to find another female.
Scattering of Ice Particles at Microwave Frequencies: A Physically Based Parameterization
Authors: Kim Min-Jeong , Kulie Mark S. , O’Dell Chris , Bennartz Ralf
Published: May 2007

This paper presents a new, purely physical approach to simulate ice-particle scattering at microwave frequencies. Temperature-dependent ice particle size distributions measured by aircraft in midlatitude frontal systems are used to represent the distribution of precipitation-sized frozen hydrometeors above the freezing level through derived radar reflectivity–snow water content (Z–M) relationships. The discrete dipole approximation is employed to calculate optical properties of selected types of idealized nonspherical ice particles (hexagonal columns, four-arm rosettes, and six-arm rosettes). Based on those assumptions, passive microwave optical properties are calculated using radar observations from Gotland Island in the Baltic Sea. These forward-simulated brightness temperatures are compared with observed data from both the Advanced Microwave Scanning Radiometer (AMSR-E) and the Advanced Microwave Sounding Unit-B (AMSU-B). Results show that the new ice scattering/microphysics model is able to generate brightness temperatures that are consistent with AMSR and AMSU-B observations of two light-winter-precipitation cases. The overall differences among the various ice-habit results at 89 GHz are generally not that expansive, whereas the AMSU-B 150-GHz comparisons show increased sensitivity to ice-particle shapes.
Giant and Ultragiant Aerosol Particle Variability over the Eastern Great Lakes Region
Authors: Lasher-Trapp Sonia , Stachnik Justin P.
Published: May 2007

Numerous studies have indicated the potential for giant and ultragiant aerosol particles to expedite the warm-rain process as a result of their extreme sizes. The central question regarding their importance is, Are they present in large enough numbers to influence the microphysics of the clouds significantly? Thus, quantification of these particles and their variability is paramount. New observations collected during the second Alliance Icing Research Study (AIRS II) are presented as evidence of the presence and variability of giant and ultragiant aerosol particles over a continental region—in this case, within the eastern Great Lakes region and parts of the midwestern United States and Canada during one month in winter 2003. Sources and factors contributing to the amount of these particles observed in the lower atmosphere were difficult to identify separately; future studies incorporating high-resolution weather modeling are likely needed.
Gender, Framing, and Travelogues
Authors: Pan Steve , Ryan Chris
Published: May 2007

This article analyzes gender differences in visiting media reporting of a tourism destination. Based on the concept of frame analysis, a method commonly used in media studies, it combines the analysis of texts and pictures from print media travel reports and assigned rankings to different frames (themes) identified for further statistical analysis. Using an independent-samples t -test and multidimensional scaling, it was found that female journalists pick up subtler and less salient frames more frequently than their male counterparts. However, significant differences were only found in three themes: “cuisine,” “adventure activities,” and “urban vibrancy.” On the other hand, reports by male journalists were more congruent with ranking of themes promoted by national tourism organizations than was the case among their female counterparts. In general, for soft news such as travelogues, gender differences were found in the less salient themes. Managerial implications, suggestions for future research, and limitations are provided and discussed.
Does Inbound Tourism Benefit Developing Countries? A Trade Theoretic Approach
Authors: Sahli Mondher , Nowak Jean-Jacques
Published: May 2007

Public policy makers in developing economies are often faced with the question of whether inbound tourism growth plays a catalytic role in the overall economic development. This article challenges the popular assumption, and the implicit assertion within much of the literature, that tourism is an effective vehicle of welfare improvement. It does so by providing a broader theoretic approach for examining tourism within an integrated trade framework.
The Roles of Quality and Intermediary Constructs in Determining Festival Attendees' Behavioral Intention
Authors: So Yon Lee  , Petrick James F. , Crompton John
Published: May 2007

This study is an examination of the relationships between visitors' perceived service quality, perceived service value, satisfaction and behavioral intentions. Respondents were visitors who attended the Cajun Catfish Festival in Conroe, Texas and were systematically selected. Findings revealed that: (a) a structural model operationalizing perceived service quality as a set of attributes predicted visitors' intention to visit the festival better than an alternative model that measured quality by using a visitor's judgment about a service's overall excellence or superiority; (b) among the constructs analyzed, perceived service value appeared to be the best predictor of behavioral intentions; and (c) of the four dimensions of service quality of a festival, generic features and comfort amenities had the most influence on determining perceived service quality.
Heritage Tourism on Route 66: Deconstructing Nostalgia
Authors: Caton Kellee , Santos Carla Almeida
Published: May 2007

Many scholars have criticized the phenomenon of heritage tourism, arguing that it is driven by nostalgia, the desire on the part of heritage tourists to relive a glorified, misremembered version of the past; however, few studies have examined the actual experiences of heritage tourists. Employing a framework of heuristic inquiry, this study explores nine tourists' experiences traveling along the Route 66 National Historic Corridor, using methodological techniques of in-depth active interviewing, personal reflection, narrative inquiry, and photo elicitation in order to begin to evaluate the explanatory power of nostalgia theory in this context. Study participants identified various meaningful elements of their travel experiences, including historical education, interaction with diverse landscapes, interaction with hosts, and personal growth; however, their experiences did not appear to be characterized by nostalgia, as it is conceptualized in the tourism literature. The study thus emphasizes the importance of considering tourists' interpretations of their experiences when generating theory about tourism phenomena.
Meanings of Menopause
Authors: Hall Lisa , Callister Lynn Clark , Berry Judith A. , Matsumura Geraldine
Published: May 2007

Attitudes and sociocultural perceptions provide the context within which women experience menopause. Cultural influences greatly affect how women perceive and manage their menopausal symptoms. Cultures may be categorized based on way of life, including traditional, immigrant, and modern. Varying perceptions and symptom experiences are described, including modifiable and nonmodifiable factors that affect the level of distress women feel with menopause. Helping women actively participate in management of menopausal symptoms including self-care strategies will contribute to feelings of control of menopausal symptoms and overall health. By using the highest levels of evidence regarding management of menopause, becoming familiar with the cultural and psychosocial influences of menopause and then empowering women to make decisions regarding management, health care providers can improve their care of perimenopausal and menopausal women.
Developing a Teachable Point of View
Authors: Cameron Kim
Published: May 2007

As professors of management and organizational behavior mature in their teaching, they should begin to develop a teachable point of view. In this article, the author describes several attributes of a teachable point of view. Based on his own teaching experience, the author outlines five criteria for the content of the material taught—the what of teaching—as well as the pedagogical approach to engendering learning—the how of teaching. These criteria are offered as illustrations of what it means to be a full professor.
On the Synergy between Research and Teaching
Authors: Vroom Victor H.
Published: May 2007

Victor Vroom provides a revealing and insightful account of a lifetime search for integrating his dual identities as researcher and teacher. He takes us through his early transitions from teaching in the psychology department at the University of Pennsylvania through his ten-year career at Carnegie to his current role at Yale School of Management. Is there a way in which one's teaching can aid research and one's research aid teaching? Vroom believes that he has now found such synergy and provides examples of his current work to illustrate how it came about.
The concept of prehistory and the invention of the terms ‘prehistoric’ and ‘prehistorian’: the Scandinavian origin, 1833–1850
Authors: Rowley-Conwy Peter
Published: May 2007

It is usually assumed by historians of archaeology that the ‘concept of prehistory’ and the terms ‘prehistoric’ and ‘prehistorian’ first appeared in Britain and/or France in the mid-nineteenth century. This contribution demonstrates that the Scandinavian equivalent termsforhistoriskandförhistoriskwere in use substantially earlier, appearing in print first in 1834. Initial usage by Molbech differed slightly from that of the present day, but within three years the modern usage had been developed. The concept of prehistory was first developed at the same time by C.J. Thomsen, though he did not use the word. It was used more frequently in the nationalism debates of the 1840s, particularly by J.J.A. Worsaae. One of the other protagonists, the Norwegian Peter Andreas Munch, was probably responsible for introducing the concept to Daniel Wilson in 1849, and suggesting that an English equivalent toforhistoriskwas required.