bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Ivabradine on the Pulmonary Vein Electrical Activity and Modulation of Pacemaker Currents and Calcium Homeostasis
Authors: SUENARI KAZUYOSHI , CHENG CHEN‐CHUAN , CHEN YAO‐CHANG , LIN YUNG‐KUO , NAKANO YUKIKO , KIHARA YASUKI , CHEN SHIH‐ANN , CHEN YI‐JEN
Published: September 2011

Effects of Ivabradine on Pulmonary Veins. Introduction: Ivabradine is a novel heart rate decreasing agent with selective and specific antagonist effects on the pacemaker current (If). The aim of this study was to investigate the pharmacological effects of ivabradine on the pulmonary vein (PV) cardiomyocytes.

Methods and Results: Whole‐cell patch‐clamp techniques and the indo‐1 fluorimetric ratio technique were used to investigate the characteristics of the If and intracellular calcium (Ca 2+i) in single isolated rabbit PV cardiomyocytes with pacemaker activity before and after an ivabradine administration (0.3, 3, 10, and 30 μM). Ivabradine (0.3, 3, 10, and 30 μM) concentration dependently decreased the spontaneous activity by 6  ± 3%, 32  ± 6%, 49  ±  5%, and 85  ±  4%, and decreased the If by 35  ±  8%, 47  ± 9%, 62  ± 5%, and 65  ±  7%, respectively, in PV cardiomyocytes. The decreased extent of the PV beating rate or If by the different concentrations of ivabradine correlated well with the baseline PV beating rates. The IC50 of the spontaneous activity and If induced by ivabradine were 9.5 and 3.5 μM, respectively. Moreover, ivabradine (30 μM, but not 3 μM) decreased the Ca 2+i transient in the PV cardiomyocytes and ivabradine (30 μM) decreased the L‐type calcium current in the PV cardiomyocytes.

Conclusion: Ivabradine decreased the Ifs and Ca 2+i transient in the PV cardiomyocytes, which may contribute to its inhibitory effects on the PV spontaneous activity. (J Cardiovasc Electrophysiol, Vol. 23, pp. 200‐206, February 2012)
Cholesterol Content and Methods for Cholesterol Determination in Meat and Poultry
Authors: Dinh Thu T. N. , Thompson Leslie D. , Galyean Michael L. , Brooks J Chance , Patterson Kristine Y. , Boylan L. Mallory
Published: September 2011

Abstract:  Available data for cholesterol content of beef, pork, poultry, and processed meat products were reported. Although the cholesterol concentration in meat and poultry can be influenced by various factors, effects of animal species, muscle fiber type, and muscle fat content are focused on in this review. Oxidative red muscles tend to have greater total lipid and cholesterol contents, although differences in the same types of muscles or cuts have been reported. Moreover, contradictory results among various studies suggest that unless there are pronounced changes in muscle structure and composition, cholesterol content is unlikely to be affected. Second, multiple issues in cholesterol analysis, including sample preparation, detection, and quantification, were evaluated. Cholesterol content of meat and poultry has been determined mostly by colorimetry and chromatography, although the latter has become predominant because of technological advances and method performance. Direct saponification has been the preferred method for hydrolyzing samples because of cost‐ and time‐effectiveness. The extraction solvent varies, but toluene seems to provide sufficient recovery in a single extraction, although the possible formation of an emulsion associated with using toluene requires experience in postsaponification manipulation. The most commonly used internal standard is 5α‐cholestane, although its behavior is not identical to that of cholesterol. Cholesterol can be analyzed routinely by gas chromatography (GC)‐flame ionization detector without derivatization; however, other methods, especially high‐performance liquid chromatography (HPLC) coupled with different detectors, can also be used. For research purposes, HPLC‐ultraviolet/Visible/photodiode array detector with nondestructiveness is preferred, especially when cholesterol must be separated from other coexisting compounds such as tocopherols. More advanced methods, such as GC/HPLC‐isotope dilution/mass spectrometry, are primarily used for quality control purposes.
Antagonistic Intestinal Microflora Produces Antimicrobial Substance Inhibitory to Pseudomonas Species and Other Spoilage Organisms
Authors: Hatew Bayissa , Delessa Tenagne , Zakin Vered , Gollop Natan
Published: September 2011

Abstract:  Chicken intestine harbors a vast number of bacterial strains. In the present study, antimicrobial substance produced by lactic acid bacteria (LAB) isolated from the gastrointestinal tract of healthy chicken was detected, characterized, and purified. Based on 16S rRNA sequencing, the bacteria were identified as Lactobacillus plantarum vN. The antimicrobial substance produced by this bacterium was designated vN‐1 and exhibited a broad‐spectrum of activity against many important pathogenic and spoilage microorganisms, including Pseudomonas aeruginosa, Staphylococcus aureus, Micrococcus luteus, Salmonella Typhimurium, and Erwinia amylovova. vN‐1 was determined to be thermostable, insensitive to pH values ranging from 2.0 to 8.0, resistant to various organic solvents and to enzymatic inactivation. The inhibition kinetics displayed a bactericidal mode of action. This study revealed an antimicrobial substance with low molecular mass of less than 1 kDa as determined by ultrafiltration and having features not previously reported for LAB isolated from chicken intestines. The detection of this antimicrobial substance addresses an important aspect of biotechnological control agents of spoilage caused by Pseudomonas spp. and promises the possibility for preservation of refrigerated poultry meat.

Practical Application:  The newly characterized antimicrobial substance and designated as vN‐1 may have the potential to be used in food preservation.
Cytotoxic T‐lymphocyte antigen 4 gene +49A/G polymorphism significantly associated with susceptibility to primary biliary cirrhosis: A meta‐analysis
Authors: CHEN Rui Rui , HAN Zhe Yi , LI Jin Ge , SHI Yong Quan , ZHOU Xin Min , WANG Jing Bo , CAI Xi Qiang , WANG Xue Chang , HAN Ying , FAN Dai Ming
Published: September 2011

OBJECTIVE:  To evaluate comprehensively the association of cytotoxic T‐lymphocyte antigen 4 (CTLA‐4) +49A/G polymorphism with susceptibility to primary biliary cirrhosis (PBC).

METHODS:  PubMed was used to search for the relevant published articles. The risk of PBC association with the CTLA‐4+49A/G polymorphism was estimated for each study in a random‐effects model. Odds ratio (OR) and 95% confidence interval (CI) were estimated for each study. Risks to PBC were estimated by stratified analysis in patients with different ethnicity and antimitochondrial antibody (AMA) status, as well as histological stages.

RESULTS:  A total of 12 articles were included in the study. An association between PBC and CTLA‐4 G allele was found, overall OR = 1.20, 95% CI 1.03–1.41 (P = 0.02). However, stratification by ethnicity indicated a significant association between the G allele and PBC in Asians (OR = 1.36, 95% CI 1.12–1.65, P = 0.002), but not in Caucasians (OR = 1.15, 95% CI 0.95–1.39, P = 0.15). Moreover, AMA positive patients carrying G allele were more susceptible to PBC compared with AMA negative patients (OR = 1.23, 95% CI 1.06–1.43, P = 0.007; OR = 0.98, 95% CI 0.71–1.34, P = 0.88, respectively).

CONCLUSIONS:  Polymorphism in exon 1 of CTLA‐4 gene at position 49 may act as a candidate of susceptibility locus to PBC. However, larger studies with participants of varying ethnicity and stratified by clinical and laboratory characteristics are needed to validate our findings.
Combining refractive and topographic data in corneal refractive surgery for astigmatism
Authors: Næser Kristian
Published: September 2011

Purpose:  To provide a theoretical approach for combining refractive and topographic data in the planning of corneal laser refractive surgery for astigmatism.

Methods:  Refractive and topographic data for astigmatism were transformed to the corneal plane. Net astigmatisms were converted to polar values. An optimization process was performed with the use of differential calculus.

Results:  With this method, the magnitude of the corneal astigmatism is reduced or unaltered, while its orientation is maintained. The method identifies the reduction in corneal astigmatism, which will yield the largest reduction in refractive astigmatic magnitude.

Conclusions:  The advantage of the optimization method described in this article is a consistent reduction in corneal astigmatism towards sphericity. No new corneal astigmatism is carved on the cornea, and probably less tissue is ablated. The optimization method may also be used to combine refractive and topographic data for higher order aberrations with sinusoidal components. However, compared to the traditional purely refractive driven treatment, more refractive astigmatism will remain in the eye in most cases. A controlled clinical trial is necessary for comparing these two treatment modalities.
The role of in vivo Ca2+ signals acting on Ca2+–calmodulin‐dependent proteins for skeletal muscle plasticity
Authors: Tavi Pasi , Westerblad Håkan
Published: September 2011

Abstract  Skeletal muscle fibres are highly heterogeneous regarding size, metabolism and contractile function. They also show a large capacity for adaptations in response to alterations in the activation pattern. A major part of this activity‐dependent plasticity relies on transcriptional alterations controlled by intracellular Ca2+ signals. In this review we discuss how intracellular Ca2+ fluctuations induced by activation patterns likely to occur in vivo control muscle properties via effects on Ca2+–calmodulin‐dependent proteins. We focus on two such Ca2+ decoders: calcineurin and Ca2+–calmodulin‐dependent protein kinase II. Inherent Ca2+ transients during contractions differ rather little between slow‐ and fast‐twitch muscle fibres and this difference is unlikely to have any significant impact on the activity of Ca2+ decoders. The major exception to this is fatigue‐induced changes in Ca2+ transients that occur in fast‐twitch fibres exposed to high‐intensity activation typical of slow‐twitch motor units. In conclusion, the cascade from neural stimulation pattern to Ca2+‐dependent transcription is likely to be central in maintaining the fibre phenotypes in both fast‐ and slow‐twitch fibres. Moreover, changes in Ca2+ signalling (e.g. induced by endurance training) can result in altered muscle properties (e.g. increased mitochondrial biogenesis) and this plasticity involves other signalling pathways.
Postsynaptic density‐95 scaffolding of Shaker‐type K+ channels in smooth muscle cells regulates the diameter of cerebral arteries
Authors: Joseph Biny K. , Thakali Keshari M. , Pathan Asif R. , Kang Eunju , Rusch Nancy J. , Rhee Sung W.
Published: September 2011

Non‐Technical Summary  Shaker‐type potassium channels are found on the smooth muscle cells of blood vessels in the brain and are important in keeping the blood vessels open or dilated. We show that a protein called PSD95, previously found in nerve cells, interacts with these potassium channels. PSD95 may act as a scaffold to ensure that the potassium channels are expressed in adequate numbers and in the right location on the smooth muscle cells. When we reduced the number of PSD95 proteins, we saw that the potassium channels were also reduced and the blood vessels were not as dilated compared to blood vessels with normal amounts of PSD95. This research may help us understand how abnormal constriction of blood vessels in the brain occurs in diseases such as high blood pressure and stroke.
Eco-Driving Performance Assessment With in-Car Visual and Haptic Feedback Assistance
Authors: Azzi S. , Reymond G. , Mérienne F. , Kemeny A.
Published: September 2011

In this experiment, 28 participants completed an urban driving task in a highly immersive driving simulator at Renault’s Technical Centre for Simulation. This simulator provides a 150 deg field of view in a fully instrumented cockpit. Two different eco-driving assistance devices were added: a visual display on the midconsole and a force feedback system on the gas pedal, in order to apply an additionnal reaction torque on drivers’ foot. The feedback information was computed by comparing the car’s instant acceleration with an optimal acceleration level based on a proprietary consumption model of a Renault diesel engine. This experiment has three main goals: I. Assess the contribution of verbal instructions to eco-driving performance; II. Quantify the additional contribution generated by two eco-driving assistance systems (visual and haptic); III. Measure drivers’ acceptance of haptic eco-driving assistance system. Basic eco-driving instructions, such as changing gears under 2000 Rpm, yield significant decrease of polluting emissions. Assisting drivers with visual, haptic, or visual-haptic on-board devices, in addition to low engine speed verbal instructions, lead to supplementary significant savings of polluting emissions. There is no significant difference between assistance feedback type; suggesting that the haptic feedback provides the same ecoperformance as visual feedback. In particular, subjects show good adaptation to the haptic feedback pedal at first utilization of the system. They apparently relied more on haptic modality to achieve the eco-driving task, when they used both visual and haptic assistance.
Feedback Circuits Monitor and Adjust Basal Lck-Dependent Events in T Cell Receptor Signaling
Authors: Schoenborn Jamie R. , Tan Ying Xim , Zhang Chao , Shokat Kevan M. , Weiss Arthur
Published: September 2011

Signaling molecules downstream of the TCR are poised to rapidly respond to receptor activation.
Protein Arginine Methyltransferase 5 Regulates ERK1/2 Signal Transduction Amplitude and Cell Fate Through CRAF
Authors: Andreu-Pérez Pedro , Esteve-Puig Rosaura , de Torre-Minguela Carlos , López-Fauqued Marta , Bech-Serra Joan Josep , Tenbaum Stephan , García-Trevijano Elena R. , Canals Francesc , Merlino Glenn , Ávila Matías A. , Recio Juan A.
Published: September 2011

Arginine methylation of RAF proteins limits ERK activation after growth factor stimulation, thereby determining the biological response.
Fusobacterium nucleatum and Human Beta-Defensins Modulate the Release of Antimicrobial Chemokine CCL20/Macrophage Inflammatory Protein 3α
Authors: Ghosh Santosh K. , Gupta Sanhita , Jiang Bin , Weinberg Aaron
Published: September 2011

Cells of the innate immune system regulate immune responses through the production of antimicrobial peptides, chemokines, and cytokines, including human beta-defensins (hBDs) and CCL20. In this study, we examined the kinetics of primary human oral epithelial cell (HOEC) production of CCL20 and hBDs in response toFusobacterium nucleatum, a commensal bacterium of the oral cavity, which we previously showed promotes HOEC induction of hBDs. HOECs secrete maximal levels of CCL20 at 6 h, following stimulation byF. nucleatumcell wall (FnCW). The kinetics of CCL20 release is distinct from that of hBD-2 and -3, which peaks after 24 h and 48 h of FnCW stimulation, respectively. FnCW-induced release of CCL20 by HOECs requires both transcriptional and translational activation. Release of CCL20 by HOECs is inhibited by brefeldin A, suggesting that it is secreted through a vesicle transport pathway. Other epithelium-derived agents that FnCW induces, such as hBD-2, hBD-3, tumor necrosis factor alpha (TNF-α) and interleukin-1β (IL-1β), are also able to release CCL20. By focusing on mitogen-activated protein kinases, we show that both extracellular signal-regulated kinase 1/2 and p38, but not JNK, are required for hBD-, TNF-α-, and IL-1β-induced secretion of CCL20 by HOECs. The ability of FnCW and its induced hBDs to produce proinflammatory cytokines and CCL20 suggests the broad role ofF. nucleatumand human antimicrobial peptides in primary immune responses elicited by oral epithelium.
Cathepsin G and Neutrophil Elastase Play Critical and Nonredundant Roles in Lung-Protective Immunity against Streptococcus pneumoniae in Mice
Authors: Hahn Ines , Klaus Anna , Janze Ann-Kathrin , Steinwede Kathrin , Ding Nadine , Bohling Jennifer , Brumshagen Christina , Serrano Hélène , Gauthier Francis , Paton James C. , Welte Tobias , Maus Ulrich A.
Published: September 2011

Neutrophil serine proteases cathepsin G (CG), neutrophil elastase (NE), and proteinase 3 (PR3) have recently been shown to contribute to killing of
Streptococcus pneumoniae
in vitro
. However, their relevance in lung-protective immunity against different serotypes of
S. pneumoniae
in vivo
has not been determined so far. Here, we examined the effect of CG and CG/NE deficiency on the lung host defense against
S. pneumoniae
in mice. Despite similar neutrophil recruitment, both CG knockout (KO) mice and CG/NE double-KO mice infected with focal pneumonia-inducing serotype 19
S. pneumoniae
demonstrated a severely impaired bacterial clearance, which was accompanied by lack of CG and NE but not PR3 proteolytic activity in recruited neutrophils, as determined using fluorescence resonance energy transfer (FRET) substrates. Moreover, both CG and CG/NE KO mice but not wild-type mice responded with increased lung permeability to infection with
S. pneumoniae
, resulting in severe respiratory distress and progressive mortality. Both neutrophil depletion and ablation of hematopoietic CG/NE in bone marrow chimeras abolished intra-alveolar CG and NE immunoreactivity and led to bacterial outgrowth in the lungs of mice, thereby identifying recruited neutrophils as the primary cellular source of intra-alveolar CG and NE. This is the first study showing a contribution of neutrophil-derived neutral serine proteases CG and NE to lung-protective immunity against focal pneumonia-inducing serotype 19
S. pneumoniae
in mice. These data may be important for the development of novel intervention strategies to improve lung-protective immune mechanisms in critically ill patients suffering from severe pneumococcal pneumonia.
Insight into Bacterial Virulence Mechanisms against Host Immune Response via the Yersinia pestis-Human Protein-Protein Interaction Network
Authors: Yang Huiying , Ke Yuehua , Wang Jian , Tan Yafang , Myeni Sebenzile K. , Li Dong , Shi Qinghai , Yan Yanfeng , Chen Hui , Guo Zhaobiao , Yuan Yanzhi , Yang Xiaoming , Yang Ruifu , Du Zongmin
Published: September 2011

A
Yersinia pestis
-human protein interaction network is reported here to improve our understanding of its pathogenesis. Up to 204 interactions between 66
Y. pestis
bait proteins and 109 human proteins were identified by yeast two-hybrid assay and then combined with 23 previously published interactions to construct a protein-protein interaction network. Topological analysis of the interaction network revealed that human proteins targeted by
Y. pestis
were significantly enriched in the proteins that are central in the human protein-protein interaction network. Analysis of this network showed that signaling pathways important for host immune responses were preferentially targeted by
Y. pestis
, including the pathways involved in focal adhesion, regulation of cytoskeleton, leukocyte transendoepithelial migration, and Toll-like receptor (TLR) and mitogen-activated protein kinase (MAPK) signaling. Cellular pathways targeted by
Y. pestis
are highly relevant to its pathogenesis. Interactions with host proteins involved in focal adhesion and cytoskeketon regulation pathways could account for resistance of
Y. pestis
to phagocytosis. Interference with TLR and MAPK signaling pathways by
Y. pestis
reflects common characteristics of pathogen-host interaction that bacterial pathogens have evolved to evade host innate immune response by interacting with proteins in those signaling pathways. Interestingly, a large portion of human proteins interacting with
Y. pestis
(16/109) also interacted with viral proteins (Epstein-Barr virus [EBV] and hepatitis C virus [HCV]), suggesting that viral and bacterial pathogens attack common cellular functions to facilitate infections. In addition, we identified vasodilator-stimulated phosphoprotein (VASP) as a novel interaction partner of YpkA and showed that YpkA could inhibit
in vitro
actin assembly mediated by VASP.
High-risk behaviour in steady and in casual relationships among men who have sex with men in Israel
Authors: Mor Zohar , Davidovich Udi , Bessudu-Manor Niva , McFarlane Mary , Feldshtein Gil , Chemtob Daniel
Published: September 2011

Objective

To explore the differences in sexual risk behaviour between men who have sex with men (MSM) with steady partners versus casual partner(s) in the gay community.

Methods

This online cross-sectional convenience-sampling study assessed MSM practices, their knowledge and their motivation regarding safe sex. Participants not knowing their HIV status or who performed insertive or receptive unprotected anal intercourse (UAI) or with a sex partner whose HIV status was unknown or discordant were considered ‘at-risk’.

Results

Of all 2569 participants who completed the questionnaire, 907/2569 (35.3%) had a steady partner, and 896/2569 (34.9%) had a casual partner(s) in the past 6 months. 262/907 (28.9%) with steady partners and 248/896 (27.7%) with casual partners demonstrated at-risk sexual behaviour. Of all participants with steady partners, 108/907 (11.9%) performed UAI with their partner without undergoing mutual HIV testing. Of all participants with steady partners, 476/907 (52.5%) had a concurrent casual partner, and 144/476 (30.3%) performed UAI with both the steady and the casual partner. Of all participants with steady partners, 775/907 (85.4%) negotiated the possibility of sex outside their relationship with their main partner. The length of the steady relationship correlated with the number of concurrent casual partners.

Conclusions

At-risk sexual behaviour was associated with insufficient negotiation skills, difficulties in condom use and a general risk-taking profile. Health educators should encourage MSM with steady partners to perform HIV testing before practising UAI, to improve their negotiation skills during the contact and to support open discussions with regard to sexual contact besides the steady relationship, as it may not be monogamous.
TheP-element-induced silencing effect ofKPtransposons is dose dependent inDrosophila melanogaster
Authors: Sameny Alireza , Locke John
Published: September 2011

Transposable elements are found in the genomes of all eukaryotes and play a critical role in altering gene expression and genome organization. In Drosophila melanogaster, transposable P elements are responsible for the phenomenon of hybrid dysgenesis. KP elements, a deletion-derivative of the complete P element, can suppress this mutagenic effect. KP elements can also silence the expression of certain other P-element-mediated transgenes in a process called P-element-dependent silencing (PDS), which is thought to involve the recruitment of heterochromatin proteins. To explore the mechanism of this silencing, we have mobilized KP elements to create a series of strains that contain single, well-defined KP insertions that show PDS. To understand the quantitative role of KP elements in PDS, these single inserts were combined in a series of crosses to obtain genotypes with zero, one, or two KP elements, from which we could examine the effect of KP gene dose. The extent of PDS in these genotypes was shown to be dose dependent in a logarithmic rather than linear fashion. A logarithmic dose dependency is consistent with the KP products interacting with heterochromatic proteins in a concentration-dependent manner such that two molecules are needed to induce gene silencing.
AN ANALOG FLUID MODEL FOR SOME TACHYONIC EFFECTS IN FIELD THEORY
Authors: ARIAS E. , BÉSSA C. H. G. , SVAITER N. F.
Published: September 2011

We consider the sound radiation from an acoustic point-like source moving along a supersonic ("space-like") trajectory in a fluid at rest. We call it an acoustic "tachyonic" source. We describe the radiation emitted by this supersonic source. After quantizing the acoustic perturbations, we present the distribution of phonons generated by this classical tachyonic source and the classical wave interference pattern.
ISOSPIN–SPIN INTERCHANGE SYMMETRY AND TWO-BARYON BOUND STATES IN (3+1)-DIMENSIONAL LATTICE QCD WITH TWO-FLAVORS AND STRONG COUPLING
Authors: FARIA DA VEIGA PAULO A. , O'CARROLL MICHAEL , FRANCISCO NETO ANTÔNIO
Published: September 2011

We determine two-baryon bound states in a 3+1 lattice QCD model with improved Wilson action and two flavors. We work in the strong coupling regime: small hopping parameter κ > 0 and much smaller plaquette coupling β > 0. In this regime, it is known that the low-lying energy–momentum spectrum is comprised of baryons and mesons with asymptotic masses -3 ln κ and -2 ln κ, respectively. We show that the dominant baryon–baryon interaction is an order κ2 space-range-one [Formula: see text]-exchange potential. We also show that this interaction has an important and novel isospin–spin interchange symmetry relating the various possible bound states, and then governing the two-baryon spectral structure. Letting S(I) denote the total spin (total isospin) of the two-baryon bound states, S, I = 0, 1, 2, 3, we find bound states with asymptotic binding energy κ2/4, for I+S = 1, 3, and 4 (here, with I = S = 2); κ2/12, for I+S = 0, 2, 4 and 3 (here, with I = 1, 2). In particular, we show that the two-baryon spectrum contains deuteron (I = 0), diproton (I = 1) and dineutron (I = 1)-like bound states. Using the isospin–spin symmetry, we can circumvent the lack of spin symmetry of the lattice action and show they all have the same asymptotic binding energy, namely κ2/4. Our analysis uses convenient two and four-baryon correlations, their spectral representations and a lattice Bethe–Salpeter equation, which is solved in a ladder approximation. For the isospin, spin part of the interaction, we obtain a permanent representation which describes the interaction of the individual spins and isospins of the quarks of one baryon with those of the other baryon.
Platypnea-Orthodeoxia: An Unusual Case of Hypoxemia
Authors: Slim Jennifer , McNear Jennifer , Beck Rachel , Saad Robert , Alvarez Jorge , Slim Ahmad
Published: September 2011

A 52 year old female presented for two weeks of acute onset dyspnea on exertion. She was found to be hypoxic with a room air saturation of 88%. Baseline echocardiogram was normal with the exception of aortic root dilation. Right and left heart catheterizations were performed. The coronary arteries were normal in original and without disease. The right heart catheterization demonstrated normal pulmonary pressures and “no evidence of intra-cardiac shunt”. Repeat echocardiogram was performed with agitated saline contrast and revealed a small amount of right to left shunting across the intra-atrial septum with cough while supine and significant right to left shunting while upright; these findings were consistent with the presence of a patent foramen ovale (PFO) and platypnea-orthodeoxia syndrome. The patient underwent percutaneous closure of her PFO with an Amplatzer device, and exhibited rapid resolution of her symptoms and hypoxia. She is off oxygen and has returned to work as a nurse practitioner. The case highlights the importance of clinical vigilance and consideration of this syndrome in the differential diagnosis of unexplained hypoxia. Our patient had a dramatic and positive outcome: complete alleviation of dyspnea and oxygen dependence after PFO closure.
Findings on Preoperative Brain MRI Predict Histopathology in Children with Cerebellar Neoplasms
Authors: Forbes Jonathan A. , Reig Adam S. , Smith Jason G. , Jermakowicz Walter , Tomycz Luke , Shay Sheila D. , Sun David A. , Wushensky Curtis A. , Pearson Matthew M.
Published: September 2011

Background/Aims: The majority of pediatric patients with cerebellar neoplasms harbor pilocytic astrocytomas (PAs), medulloblastomas, or ependymomas. Knowledge of a preoperative likelihood of histopathology in this group of patients has the potential to influence many aspects of care. Previous studies have demonstrated hyperintensity on diffusion-weighted imaging to correlate with medulloblastomas. Recently, measurement of T2-weighted signal intensity (T2SI) was shown to be useful in identification of low-grade cerebellar neoplasms. The goal of this study was to assess whether objective findings on these MRI sequences reliably correlated with the underlying histopathology. Methods: We reviewed the radiologic findings of 50 pediatric patients who underwent resection of a cerebellar neoplasm since 2003 at our institution. Region of interest placement was used to calculate the relative diffusion-weighted signal intensity (rDWSI) and relative T2SI (rT2SI) of each neoplasm. Results: Tukey’s multiple comparison test demonstrated medulloblastomas to have significantly higher rDWSIs than PAs/ependymomas, and PAs to have significantly higher rT2SIs than medulloblastomas/ependymomas. A simple method consisting of sequential measurement of rDWSI and rT2SI to predict histopathology was then constructed. Using this method, 39 of 50 (78%) tumors were accurately predicted. Conclusion: Measurement of rDWSI and rT2SI using standard MRI of the brain can be used to predict histopathology with favorable accuracy in pediatric patients with cerebellar tumors.
Stereological Estimation of Epidermal Volumes and Dermo-Epidermal Surface Area in Normal Skin
Authors: Kamp S. , Balkert L.S. , Stenderup K. , Rosada C. , Pakkenberg B. , Kemp K. , Jemec G.B. , Dam T.N.
Published: September 2011

Quantitative morphological studies of the healthy epidermis are essential in providing a range of parameter estimates that can be considered within the range of normality. Stereology is a set of statistical tools that provides potentially unbiased and precise estimates of 3-dimensional tissue characteristics from 2-dimensional sections. We set out to establish reference values for the volume of the viable epidermis contained within a four-millimetre punch biopsy (Vepi), the volume of the stratum corneum (VSC) and the surface area of the dermo-epidermal junction(ADEJ) in 4 predetermined body regions by use of stereology. Four-millimetre punch biopsies were taken from 20 freshly diseased corpses, fixed in formalin and embedded in paraffin. Vepi, VSC and ADEJ were established stereologically for all 4 body locations followed by pairwise comparison of means after Bonferroni correction. Vepi was significantly larger in the sole compared to all other body locations (p < 0.01). Furthermore, linear regression analysis showed a strong linear relationship between Vepi and VSC in the sole (r = 0.70). Our results suggest that the viable layers of the epidermis might also serve a mechanical function, either directly or by providing the stratum corneum with keratinocytes to support the hyperkeratosis in the weight-bearing parts of the skin.
A Reconstruction of Madden–Julian Oscillation Variability from 1905 to 2008
Authors: Oliver Eric C. J. , Thompson Keith R.
Published: September 2011

The most widely accepted characterization of the Madden–Julian oscillation (MJO) is the bivariate index developed by Wheeler and Hendon. This index relies in part on satellite-based observations of outgoing longwave radiation and thus is not defined for the presatellite era. The MJO is known to have a strong signature in surface pressure, and daily measurements of this variable are available as far back as the late nineteenth century. This study undertakes a statistical reconstruction of the Wheeler and Hendon MJO index from 1905 to 2008 based on tropical surface pressures estimated recently by the twentieth-century reanalysis project. The temporal and spectral properties of the reconstructed index are first shown to be consistent with the Wheeler and Hendon index over the common period (1979–2008). The reconstructed index is then validated over the earlier period (1905–1978) by examining its relationship with cloud cover, surface wind, precipitation, and sea level. These relationships are shown to be consistent with corresponding results obtained from the Wheeler and Hendon index over the shared period and stable over the earlier period. Finally, a simple damped harmonic oscillator model is used to gain new insights into the predictability of the MJO index and also demonstrate consistency between the reconstructed index and the Wheeler and Hendon index. These results give confidence in the validity of the historical reconstruction of the MJO index over the last century.
Sexual Adjustment to Androgen Deprivation Therapy
Authors: Walker Lauren M. , Robinson John W.
Published: September 2011

More than half of all men with prostate cancer will be treated with androgen deprivation therapy (ADT) at some point during their lives. Though an effective treatment for prostate cancer, ADT results in profound changes in the man’s sense of masculinity and sexuality (e.g., erectile dysfunction, loss of libido, genital atrophy and severe genital shrinkage, hot flashes, loss of muscle mass, fatigue, bodily feminization). These changes usually result in the cessation of all sexual activity. Surprisingly, some couples do find ways of continuing to have satisfying sex despite the man’s castrate level of testosterone. Herein, we describe the sexual struggles that couples encounter when attempting to adapt sexually to ADT. A grounded theory methodology was used to analyze interview data. The successful strategies that couples used to overcome struggles, as well as those which seemed to exacerbate struggles, are documented. Couples adjusting to ADT might benefit from knowing which strategies are most likely to result in positive adjustment and which are not.
Effect of three cations on the stability and microstructure of protein aggregate from duck egg white under alkaline condition
Authors: Ganasen P. , Benjakul S.
Published: September 2011

Pidan (alkaline egg) has been consumed widely in oriental countries and lead, a toxic element, has been used traditionally to yield the desirable characteristics. For safety concerns, alternative cations can be used for the production of pidan with comparable properties to traditionally prepared pidan. Turbidity measured as absorbance at 400 nm and microstructure of duck egg white proteins at pH 12 as influenced by three cations at various levels were investigated. Turbidity and particle size of egg white protein (20 g/kg) in 10 g/kg NaCl sample with CaCl2, PbO2 or ZnCl2 added at a level of 1 g/kg increased with time up to 1 h, followed by a decrease (p < 0.05). Nevertheless, the turbidity was retained more in samples added with PbO2, suggesting high stability of the aggregate formed. Zeta potential showed that the aggregates treated with PbO2 had a comparatively lower negative charge. Light microscopic studies indicated that the aggregation of egg white proteins was induced by ions but varied with the types of ions and incubation time. Therefore, PbO2 exhibited the highest stabilizing effect on egg white protein under alkaline condition. However, ZnCl2 can be used as an alternative compound even if it had lower impact on stability of aggregate of duck egg white protein.
Implications of Fiber Inadequacy in the Ketogenic Diet
Authors: Dahl Wendy J. , Niebergall Elaine J. , Owen Russell J.
Published: September 2011

Ketogenic diet therapy is a high-fat, low-carbohydrate diet that is prescribed for the treatment of intractable seizure disorders. The extreme carbohydrate restriction results in a diet providing very little dietary fiber; thus, ketogenic diet therapy often results in gastrointestinal side effects, particularly constipation. This case study describes the clinical course, birth to 9 years of age, of a girl with cerebral palsy and partial complex seizures treated with ketogenic diet therapy. The efficacy of the diet treatment, including gastrointestinal symptoms, is discussed. The potential benefits of functional fiber supplementation of the ketogenic diet are explored.
Factors Associated With the Career Choices of Hematology and Medical Oncology Fellows Trained at Academic Institutions in the United States
Authors: Horn Leora , Koehler Elizabeth , Gilbert Jill , Johnson David H.
Published: September 2011

Purpose

Factors that influence hematology-oncology fellows' choice of academic medicine as a career are not well defined. We undertook a survey of hematology-oncology fellows training at cancer centers designated by the National Cancer Institute (NCI) and the National Comprehensive Cancer Network (NCCN) to understand the factors fellows consider when making career decisions.

Methods

Program directors at all NCI and NCCN cancer centers were invited to participate in the study. For the purpose of analysis, fellows were grouped into three groups on the basis of interest in an academic career. Demographic data were tested with the Kruskal-Wallis test and χ2 test, and nondemographic data were tested by using the multiscale bootstrap method.

Results

Twenty-eight of 56 eligible fellowship programs participated, and 236 fellows at participating institutions responded (62% response rate). Approximately 60% of fellows graduating from academic programs in the last 5 years chose academic career paths. Forty-nine percent of current fellows ranked an academic career as extremely important. Fellows choosing an academic career were more likely to have presented and published their research. Additional factors associated with choosing an academic career included factors related to mentorship, intellect, and practice type. Fellows selecting nonacademic careers prioritized lifestyle in their career decision.

Conclusion

Recruitment into academic medicine is essential for continued progress in the field. Our data suggest that fewer than half the current fellows training at academic centers believe a career in academic medicine is important. Efforts to improve retention in academics should include focusing on mentorship, research, and career development during fellowship training and improving the image of academic physicians.
Treatment of Polycythemia Vera With Hydroxyurea and Pipobroman: Final Results of a Randomized Trial Initiated in 1980
Authors: Kiladjian Jean-Jacques , Chevret Sylvie , Dosquet Christine , Chomienne Christine , Rain Jean-Didier
Published: September 2011

Purpose

The overall impact of hydroxyurea (HU) or pipobroman treatments on the long-term outcome of patients with polycythemia vera (PV) has not been assessed in randomized studies. We report final analyses from the French Polycythemia Study Group (FPSG) study, which randomly assigned HU versus pipobroman as first-line therapy in 285 patients younger than age 65 years.

Patients and Methods

The full methodology has been described previously. FPSG results were updated with a median follow-up of 16.3 years. Statistical analysis was performed by using competing risks on the intention-to-treat population and according to main treatment received.

Results

Median survival was 17 years for the whole cohort, 20.3 years for the HU arm, and 15.4 years for the pipobroman arm (P = .008) and differed significantly from that in the general population. At 10, 15, and 20 years, cumulative incidence of acute myeloid leukemia/myelodysplastic syndrome (AML/MDS) was 6.6%, 16.5%, and 24% in the HU arm and 13%, 34%, and 52% in the pipobroman arm (P = .004). Cumulative myelofibrosis incidence at 10, 15, and 20 years according to main treatment received was 15%, 24%, and 32% with HU versus 5%, 10%, and 21% with pipobroman (P = .02).

Conclusion

Data from this unique randomized trial comparing HU with another cytoreductive drug in PV showed that (1) survival of patients with PV treated with conventional agents differed from survival in the general population, (2) evolution to AML/MDS is the first cause of death, (3) pipobroman is leukemogenic and is unsuitable for first-line therapy, and (4) incidence of evolution to AML/MDS with HU is higher than previously reported, although consideration should be given to the natural evolution of PV.
Analysis of Democratic Institutions: Structure, Conduct and Performance
Authors: Myerson Roger B
Published: September 2011

This paper develops an economic perspective on political theory as a guide to some problems and directions of current research. The electoral system and the allocation of powers to elected offices together define the game that politicians play. So democratic structures should be compared and evaluated by analyzing game models to see how equilibrium behavior of political agents may depend on the structure of the political system. The goal of such research is to predict how the conduct of politicians and the performance of government may depend on the incentives created by the structure of the political system.
Time for Revisionism on Rent Control?
Authors: Arnott Richard
Published: September 2011

Economists’ traditional hostility to rent contols is based on models that treat the housing market as perfectly competitive and on the experience with ‘hard’ controls in New York City and many European countries following World War II. The current ‘soft’ rent control systems in North America are varied and qualitatively different from earlier hard controls. The theoretical case against them is weak, particularly when the housing market is viewed as imperfectly competitive. The empirical case against them is weak, too. Economists should reconsider their blanket opposition to current rent control systems and evaluate them on a case-by-case basis.
The Economic Benefits from Immigration
Authors: Borjas George J
Published: September 2011

Natives benefit from immigration mainly because of production complementarities between immigrant workers and other factors of production, and these benefits are larger when immigrants are sufficiently ‘different’ from the stock of native productive inputs. The available evidence suggests that the economic benefits from immigration for the United States are small, on the order of $6 billion and almost certainly less than $20 billion annually. These gains, however, could be increased considerably if the United States pursued an immigration policy that attracted a more skilled immigrant flow.
Assessing the Case for Social Experiments
Authors: Heckman James J , Smith Jeffrey A
Published: September 2011

This paper analyzes the method of social experiments. The assumptions that justify the experimental method are exposited. Parameters of interest in evaluating social programs are discussed. The authors show how experiments sometimes serve as instrumental variables to identify program impacts. The most favorable case for experiments ignores variability across persons in response to treatments received and assumes that mean impacts of a program are the main object of interest in conducting an evaluation. Experiments do not identify the distribution of program gains unless additional assumptions are maintained. Evidence on the validity of the assumptions used to justify social experiments is presented.
Monetary, Credit and (Other) Transmission Processes: A Monetarist Perspective
Authors: Meltzer Allan H
Published: September 2011

Monetarist analysis of the transmission process highlights the response of relative prices and real wealth to monetary (and other) impulses. Monetary impulses are neutral in the long run. Short-run nonneutrality reflects uncertainty, incomplete information about the persistence and nature of impulses, fixed contracts, and other institutional detail. Patterns of change in relative prices have some common features but they also differ from cycle to cycle and by countries. This paper compares the monetarist analysis of intermediation to the lending view and presents evidence on the role of relative prices, lending, and other types of intermediation.
Gardens of Stone: Searching for Evidence of Secularization and Acceptance of Death in Grave Inscriptions from 1900–2009
Authors: Anderson Keith A. , Sielski Christine L. , Miles Elizabeth A. , Dunfee Alexis V.
Published: September 2011

From the magnificent to the mundane to the sublime, grave inscriptions serve as remembrances of the dead and provide concrete evidence of the thoughts and values of the day. In this study, 1,214 grave inscriptions ( N = 1,214) dated 1900 to 2009 were examined for evidence of secularization and changes in attitude toward death. Using set criteria, the researchers categorized grave inscriptions in terms of language used (sacred/secular) and acceptance of death (acceptance/other). Binary logistic regression models revealed significantly more use of sacred language and significantly less acceptance of death over the past 110 years. Findings from these analyses suggest that: (a) secularization may not be as pervasive as thought, particularly with respect to death; and (b) as death has become increasingly medicalized and marginalized, society has grown less accepting of the finitude of life. These findings are further discussed in light of the continued evolution of death memorials.
Endothelial NO/cGMP/VASP Signaling Attenuates Kupffer Cell Activation and Hepatic Insulin Resistance Induced by High-Fat Feeding
Authors: Tateya Sanshiro , Rizzo Norma O. , Handa Priya , Cheng Andrew M. , Morgan-Stevenson Vicki , Daum Guenter , Clowes Alexander W. , Morton Gregory J. , Schwartz Michael W. , Kim Francis
Published: September 2011

OBJECTIVE

Proinflammatory activation of Kupffer cells is implicated in the effect of high-fat feeding to cause liver insulin resistance. We sought to determine whether reduced endothelial nitric oxide (NO) signaling contributes to the effect of high-fat feeding to increase hepatic inflammatory signaling and if so, whether this effect 1) involves activation of Kupffer cells and 2) is ameliorated by increased NO signaling.

RESEARCH DESIGN AND METHODS

Effect of NO/cGMP signaling on hepatic inflammation and on isolated Kupffer cells was examined in C57BL/6 mice, eNos−/− mice, and Vasp−/− mice fed a low-fat or high-fat diet.

RESULTS

We show that high-fat feeding induces proinflammatory activation of Kupffer cells in wild-type mice coincident with reduced liver endothelial nitric oxide synthase activity and NO content while, conversely, enhancement of signaling downstream of endogenous NO by phosphodiesterase-5 inhibition protects against high fat–induced inflammation in Kupffer cells. Furthermore, proinflammatory activation of Kupffer cells is evident in eNos−/− mice even on a low-fat diet. Targeted deletion of vasodilator-stimulated phosphoprotein (VASP), a key downstream target of endothelially derived NO, similarly predisposes to hepatic and Kupffer cell inflammation and abrogates the protective effect of NO signaling in both macrophages and hepatocytes studied in a cell culture model.

CONCLUSIONS

These results collectively imply a physiological role for endothelial NO to limit obesity-associated inflammation and insulin resistance in hepatocytes and support a model in which Kupffer cell activation during high-fat feeding is dependent on reduced NO signaling. Our findings also identify the NO/VASP pathway as a novel potential target for the treatment of obesity-associated liver insulin resistance.
The Effect of Ceramic Restoration Shade and Thickness on the Polymerization of Light- and Dual-cure Resin Cements
Authors: Kilinc E , Antonson SA , Hardigan PC , Kesercioglu A
Published: September 2011

Clinical Relevance

Resin cements are generally considered as the material of choice in cementation of all-ceramic restorations. The decision between light- and dual-cure resin cement may depend on the properties of the ceramic restoration as well as the location of the tooth. The ceramic thickness has a more intense effect on polymerization than ceramic shade.
Cross-Compatibility of Methacrylate-Based Resin Composites and Etch-and-Rinse One-Bottle Adhesives
Authors: Sabatini C , Campillo M , Hoelz S , Davis EL , Munoz CA
Published: September 2011

Clinical Relevance

Cross-compatibility between different combinations of methacrylate-based resin composites and etch-and-rinse one-bottle adhesives was evidenced for products from different manufacturers. This represents a desirable property of adhesives as it allows the flexibility to select different composite systems based on the specific restorative needs.