bluuebunny/crossref_metadata_2025 huggingface dataset:
Inhibitory Effect of Statins on Renal Epithelial-to-Mesenchymal Transition
Authors: Patel Sharmila , Mason Roger M. , Suzuki Jun , Imaizumi Atsushi , Kamimura Takashi , Zhang Zhi
Published: July 2006

Background/Aim: Recent studies have suggested that statins may play a role in the protection against renal failure which is independent of cholesterol reduction. Activation of RhoGTPases is a key step in renal tubular cells’ epithelial-to-mesenchymal transition (EMT) which contributes to renal interstitial fibrosis. We hypothesized that statins could act by inhibiting the synthesis of the isoprenoids, such as geranylgeranyl pyrophosphate, which is essential for membrane attachment and biological activity of RhoGTPases, RhoA and Rac1. Methods: Human proximal tubular epithelial cells (HK2) were used to examine the inhibitory effect of statins on EMT induced with medium conditioned by activated peripheral blood mononuclear cells. Results: Our study demonstrates that the statins lovastatin, simvastatin, and pravastatin inhibit HK2 cells to undergo EMT. Inhibition of EMT in HK2 cells with these statins resulted in a reduction of RhoA and Rac1 activation in both the cytoplasmic and membrane-bound forms, in preservation of the expression of the epithelial cell markers E-cadherin and cytokeratin-19, and in a decrease in Fn-EDA expression, a marker for the myofibroblast phenotype. The decreased levels of activated RhoA and Rac1 in both the cytoplasmic and membrane fractions of the cells were reversed by geranylgeranyl pyrophosphate and mevalonate, and thus attributable to the inhibition of isoprenylation of RhoGTPases by statins. Conclusion: This phenomenon could explain the beneficial effect of statins on EMT and on renal fibrosis prevention.
Dynamics of Synoptic Eddy and Low-Frequency Flow Interaction. Part I: A Linear Closure
Authors: Jin F-F. , Pan L-L. , Watanabe M.
Published: July 2006

The interaction between synoptic eddy and low-frequency flow (SELF) has been recognized for decades to play an important role in the dynamics of the low-frequency variability of the atmospheric circulation. In this three-part study a linear framework with a stochastic basic flow capturing both the climatological mean flow and climatological measures of the synoptic eddy flow is proposed. Based on this linear framework, a set of linear dynamic equations is derived for the ensemble-mean eddy forcing that is generated by anomalous time-mean flows. By assuming that such dynamically determined eddy-forcing anomalies approximately represent the time-mean anomalies of the synoptic eddy forcing and by using a quasi-equilibrium approximation, an analytical nonlocal dynamical closure is obtained for the two-way SELF feedback. This linear closure, directly relating time-mean anomalies of the synoptic eddy forcing to the anomalous time–mean flow, becomes an internal part of a new linear dynamic system for anomalous time–mean flow that is referred to as the low-frequency variability of the atmospheric circulation in this paper.

In Part I, the basic approach for the SELF closure is illustrated using a barotropic model. The SELF closure is tested through the comparison of the observed eddy-forcing patterns associated with the leading low-frequency modes with those derived using the SELF feedback closure. Examples are also given to illustrate an important role played by the SELF feedback in regulating the atmospheric responses to remote forcing. Further applications of the closure for understanding the dynamics of low-frequency modes as well as the extension of the closure to a multilevel primitive equation model will be given in Parts II and III, respectively.
Empirical Mode Reduction in a Model of Extratropical Low-Frequency Variability
Authors: Kondrashov D. , Kravtsov S. , Ghil M.
Published: July 2006

This paper constructs and analyzes a reduced nonlinear stochastic model of extratropical low-frequency variability. To do so, it applies multilevel quadratic regression to the output of a long simulation of a global baroclinic, quasigeostrophic, three-level (QG3) model with topography; the model's phase space has a dimension of O(104).

The reduced model has 45 variables and captures well the non-Gaussian features of the QG3 model's probability density function (PDF). In particular, the reduced model's PDF shares with the QG3 model its four anomalously persistent flow patterns, which correspond to opposite phases of the Arctic Oscillation and the North Atlantic Oscillation, as well as the Markov chain of transitions between these regimes. In addition, multichannel singular spectrum analysis identifies intraseasonal oscillations with a period of 35–37 days and of 20 days in the data generated by both the QG3 model and its low-dimensional analog.

An analytical and numerical study of the reduced model starts with the fixed points and oscillatory eigenmodes of the model's deterministic part and uses systematically an increasing noise parameter to connect these with the behavior of the full, stochastically forced model version. The results of this study point to the origin of the QG3 model's multiple regimes and intraseasonal oscillations and identify the connections between the two types of behavior.
The Response of Damaging Winds of a Simulated Tropical Cyclone to Finite-Amplitude Perturbations of Different Variables
Authors: Hoffman R. N. , Henderson J. M. , Leidner S. M. , Grassotti C. , Nehrkorn T.
Published: July 2006

Four-dimensional variational data assimilation (4DVAR) is an established data assimilation method that finds the finite-amplitude perturbation that best fits observations consistent with a priori information and model dynamics. The response of a simulated tropical cyclone to specially designed finite perturbations of selected model variables was studied with a modified version of 4DVAR. The usual goal of minimizing data misfits was replaced with a goal of reducing damaging surface winds at the end of six hours of forecast time. For this purpose a property value cost function based on topography was defined. The case studied was a 20-km simulation of a hurricane approaching the Hawaiian Islands. Each prognostic variable in turn—temperature, winds, humidity, vertical velocity, and perturbation pressure—and all prognostic variables at once were used as the control vector for the optimization problem. Of all prognostic variables examined, temperature and the horizontal wind were the most effective at reducing damaging surface winds. The wind-only perturbation was very similar to the wind component of the perturbation calculated when all prognostic variables were used at once. Calculated perturbations had scales of 0.25°C or 1 m s−1, but changes at a few grid points near the center of the storm were an order of magnitude greater. Vertical velocity and humidity perturbations alone were ineffective at reducing damaging winds. The perturbation pressure experiment failed to converge but did substantially reduce the damaging winds.
An Estimate of Tidal Energy Lost to Turbulence at the Hawaiian Ridge
Authors: Klymak Jody M. , Moum James N. , Nash Jonathan D. , Kunze Eric , Girton James B. , Carter Glenn S. , Lee Craig M. , Sanford Thomas B. , Gregg Michael C.
Published: July 2006

An integrated analysis of turbulence observations from four unique instrument platforms obtained over the Hawaiian Ridge leads to an assessment of the vertical, cross-ridge, and along-ridge structure of turbulence dissipation rate and diffusivity. The diffusivity near the seafloor was, on average, 15 times that in the midwater column. At 1000-m depth, the diffusivity atop the ridge was 30 times that 10 km off the ridge, decreasing to background oceanic values by 60 km. A weak (factor of 2) spring–neap variation in dissipation was observed. The observations also suggest a kinematic relationship between the energy in the semidiurnal internal tide (E) and the depth-integrated dissipation (D), such that D ∼ E1±0.5 at sites along the ridge. This kinematic relationship is supported by combining a simple knife-edge model to estimate internal tide generation, with wave–wave interaction time scales to estimate dissipation. The along-ridge kinematic relationship and the observed vertical and cross-ridge structures are used to extrapolate the relatively sparse observations along the length of the ridge, giving an estimate of 3 ± 1.5 GW of tidal energy lost to turbulence dissipation within 60 km of the ridge. This is roughly 15% of the energy estimated to be lost from the barotropic tide.
Tidally Forced Internal Waves and Overturns Observed on a Slope: Results from HOME
Authors: Levine Murray D. , Boyd Timothy J.
Published: July 2006

Tidal mixing over a slope was explored using moored time series observations on Kaena Ridge extending northwest from Oahu, Hawaii, during the Survey component of the Hawaii Ocean Mixing Experiment (HOME). A mooring was instrumented to sample the velocity and density field of the lower 500 m of the water column to look for indirect evidence of tidally induced mixing and was deployed on a slope in 1453-m water depth for 2 months beginning in November 2000. The semidiurnal barotropic tidal currents at this site have a significant cross-ridge component, favorable for exciting an internal tidal response. A large-amplitude response is expected, given that the slope of the topography (4.5°) is nearly the same as the slope of the internal wave group velocity at semidiurnal frequency. Density overturns were inferred from temperature profiles measured every 2 min. The number and strength of the overturns are greater in the 200 m nearest the bottom, with overturns exceeding 24 m present at any depth nearly 10% of the time. Estimates of turbulent dissipation rate ɛ were made for each overturn by associating the measured Thorpe scale with the Ozmidov scale. The average ɛ between 1300 and 1450 m for the entire experiment is about 10−8 m2 s−3, corresponding to an average Kρ of 10−3 m2 s−1. Both ɛ and Kρ decrease by about an order of magnitude by 1200 m. The occurrence of overturns and the magnitude of ɛ are both highly correlated with the tide: both with the spring–neap cycle as well as the phase of the semidiurnal tide itself. Dissipation rate varies by at least an order of magnitude over the spring–neap cycle. It appears that tidal frequency vertical shear within 200 m of the boundary leads to significant strain (vertical divergence). Most of the overturns occur during the few hours when the vertical strain is greatest. The buoyancy frequency N calculated from reordering these overturns is a factor of 3 lower than the background N. This is consistent with the following kinematic description: the internal tide first strains the mean density field, leading to regions of low N that subsequently overturn. Less regularly, overturns also occur when the internal tide strain has created relatively high stratification within 200 m of the bottom.
Propagation of Low-Mode Internal Waves through the Ocean
Authors: Rainville Luc , Pinkel Robert
Published: July 2006

The baroclinic tides play a significant role in the energy budget of the abyssal ocean. Although the basic principles of generation and propagation are known, a clear understanding of these phenomena in the complex ocean environment is only now emerging. To advance this effort, a ray model is developed that quantifies the effects of spatially variable topography, stratification, and planetary vorticity on the horizontal propagation of internal gravity modes. The objective is to identify “baroclinic shoals” where wave energy is spatially concentrated and enhanced dissipation might be expected. The model is then extended to investigate the propagation of internal waves through a barotropic mesoscale current field. The refraction of tidally generated internal waves at the Hawaiian Ridge is examined using an ensemble of mesoscale background realizations derived from weekly Ocean Topography Experiment (TOPEX)/Poseidon altimetric measurements. The path of mode 1 is only slightly affected by typical currents, although its phase becomes increasingly random as the propagation distance from the source increases. The effect of the currents becomes more dramatic as mode number increases. For modes 3 and higher, wave phase can vary between realizations by ±π only a few wavelengths from the source. This phase variability reduces the magnitude of the baroclinic signal seen in altimetric data, creating a fictitious energy loss along the propagation path. In the TOPEX/Poseidon observations, the mode-1 M2 internal tide does appear to lose significant energy as it propagates southwestward from the Hawaiian Ridge. The simulations suggest that phase modulation by mesoscale flows could be responsible for a large fraction of this apparent loss. In contrast, northeast-propagating internal tides encounter a less energetic mesoscale and should experience limited refraction. The apparent energy loss seen in the altimetric data on the north side of the ridge might indeed be real.
Managing Montana's Trust Land Old-Growth Forests
Authors: Mortimer Michael J. , McLeod Scott D.
Published: July 2006

Management of old-growth forests on Montana's school trust forestlands has been characterized by conflicting values among various interest groups and uncertainty created by political and judicial involvement. Successful agency implementation of old-growth policy typically requires domination of the political environment by the management agency and its allies. Absent sufficient political support, the agency should pursue alternative combinations of strategies designed to maximize success in the inevitable legal disputes, such as explicitly acknowledging the role of politics in scientific management of the specific issue at hand and the uncertainties inherent in the science related to management of old-growth forests.
The Economic Resource Receipt of New Mothers
Authors: Nichols Laura , Elman Cheryl , Feltey Kathryn M.
Published: July 2006

U.S. federal policies do not provide a universal social safety net of economic support for women during pregnancy or the immediate postpartum period but assume that employment and/or marriage will protect families from poverty. Yet even mothers with considerable human and marital capital may experience disruptions in employment, earnings, and family socioeconomic status postbirth. We use the National Survey of Families and Households to examine the economic resources that mothers with children ages 2 and younger receive postbirth, including employment, spouses, extended family and social network support, and public assistance. Results show that many new mothers receive resources postbirth. Marriage or postbirth employment does not protect new mothers and their families from poverty, but education, race, and the receipt of economic supports from social networks do.
Women’s Romantic Relationships After Widowhood
Authors: Moorman Sara M. , Booth Alan , Fingerman Karen L.
Published: July 2006

This study examines decisions women make about their romantic lives after widowhood. Participants were women from the Americans’ Changing Lives survey, a nationwide random sample of 3,617 Americans older than age 25 years who, in 1986, were widowed ( n = 259) or had been widowed and were remarried ( n = 49). Widowed participants provided information about their male companions and their interest in remarriage, as well as information about their social support, mental and physical health, age, and socioeconomic status. Logistic regressions revealed that younger age and greater unhappiness predicted interest in remarriage. Higher trait anxiety predicted having male companionship. Widows who had remarried had higher household incomes and worried less about finances than did widows who did not remarry. Widows appear to make choices about partners based on their individual needs and desires as well as the attributes and availability of partners.
Modeling the Impact of Diversity Management
Authors: Pitts David W.
Published: July 2006

Public management research on diversity suffers from a lack of coherence and little theory building. There have been few attempts to establish a comprehensive theoretical framework through which streams of research can unite and better inform public managers—rather, issues of recruitment, management, and cultural values are pursued as wholly separate areas of inquiry. This article critically evaluates the current ways in which public management research addresses the diversity issue and proposes a new comprehensive model for research. The model is based on three functions of diversity management: recruiting and outreach, building cultural awareness, and promoting pragmatic management policy. These functions are linked to organizational performance through a series of intermediate steps, and the resulting model for quantitative analysis is specified.
Gender Representation in the Federal Workforce
Authors: Hsieh Chih-wei , Winslow Elizabeth
Published: July 2006

This research note provides a synopsis of the current state of gender representation among racial groups in the federal workforce. Although the trend of representation is toward more diversity, disparities persist between males and females. Aggregating data from the 2000 Demographic Profile of the Federal Workforce, we examine federal workers’ demographic characteristics of gender and race/ethnicity and ask why male and female representation differs from one racial group to another. We find that although women are represented demographically in total federal positions, they are underrepresented in higher level positions. This trend varies among racial groups. We propose three factors for further research that may account for differences in gender representation: the glass ceiling, the educational attainment gap, and gender roles.
Fibronectin Immobilization using Water-soluble Carbodiimide on Poly-L-lactic Acid for Enhancing Initial Fibroblast Attachment
Authors: Nagai Megumi , Hayakawa Tohru , Makimura Masaharu , Yoshinari Masao
Published: July 2006

The aim of this study is to evaluate the influence of fibronectin immobilization on poly-L-lactic acid (PLA) films on the initial attachment of human gingival fibroblasts. Carboxylic acid groups are chemically introduced on the PLA films' surface by surface hydrolysis with 0.5 M NaOH. The contact angle of PLA surface with respect to double-distilled water decreases significantly after NaOH hydrolysis. X-ray photoelectron spectroscopy (XPS) also reveals significantly higher intensities of CC=O/CC-O after NaOH hydrolysis. Fibronectin is immobilized onto the hydrolyzed PLA surface through a condensation reaction between the carboxylic acid groups on the hydrolyzed PLA surface and the amino groups of fibronectin using water-soluble carbodiimide. XPS analysis shows that the fibronectin-immobilized PLA surface is enriched with nitrogen atoms. The immobilization of fibronectin significantly enhances the number of initially attached human gingival fibroblasts on the PLA surface. No obvious differences in morphology are noted between fibroblasts cultured on native PLA and on fibronectin-immobilized PLA. Fibronectin can be immobilized onto the PLA surface after NaOH hydrolysis and this is effective in enhancing the initial attachment of human gingival fibroblasts.
Laser Surface Modification of Ti—6Al—4V: Wear and Corrosion Characterization in Simulated Biofluid
Authors: Singh Raghuvir , Kurella A. , Dahotre Narendra B.
Published: July 2006

Laser surface melting (LSM) of Ti—6Al—4V is performed in argon to improve its properties, such as microstructure, corrosion, and wear for biomedical applications. Corrosion behavior is investigated by conducting electrochemical polarization experiments in simulated body fluid (Ringer's solution) at 37 C. Wear properties are evaluated in Ringer's solution using pin-on-disc apparatus at a slow speed.

Untreated Ti—6Al—4V contains α+β phase. After laser surface melting, it transforms to acicular α embedded in the prior β matrix. Grain growth in the range of 65—89 µm with increase in laser power from 800 to 1500 W due to increase in associated temperature is observed. The hardness of as-laserprocessed Ti—6Al—4V alloy is more (275—297 HV) than that of the untreated alloy (254 HV). Passivation currents are significantly reduced to <4.3 µA/cm2 after laser treatment compared to untreated Ti—6Al—4V (≈12 µA/cm2). The wear resistance of laser-treated Ti—6Al—4V in simulated body fluid is enhanced compared to that of the untreated one. It is the highest for the one that is processed at a laser power of 800 W. Typical micro-cutting features of abrasive wear is the prominent mechanism of wear in both untreated and as-laser-treated Ti—6Al—4V. Fragmentation of wear debris assisted by microcracking was responsible for mass loss during the wear of untreated Ti—6Al—4V in Ringer's solution.
Effect of Surface Treatments on Anodic Oxide Film Growth and Electrochemical Properties of Tantalum used for Biomedical Applications
Authors: Silva R. A. , Silva I. P. , Rondot B.
Published: July 2006

Self-expandable nitinol (nickel-titanium) alloys and 316L stainless steel are the most commonly used materials in the production of coronary stents. However, tantalum (Ta) has already been used to make stents for endovascular surgery and may constitute an alternative to other materials because of its better electrochemical performance, namely its higher corrosion resistance, as well as its radio-opacity. The characterization of wet polished, chemically polished, wet polished anodized, and chemically polished anodized Ta electrodes has been performed in a 0.15 M NaCl solution (simulated body fluid) using Ucorr=f(t) measurements, anodic polarizations, capacity measurements, anodic oxidations, and atomic force microscopy (AFM) imaging. Anodic polarization curves have shown that the abnormal current density peak with a maximum value around 1.65 V (critical applied potential, Uc) disappeared for the anodized electrodes indicating a probable relationship between the surface states and the film growth. These results are confirmed by capacity measurements. The behavior of wet polished and chemically polished electrodes during anodic oxidations seemingly indicated that for these particular treatments the film growth is different. The AFM images and roughness measurements have shown that chemical polishing produced smoother electrodes, a fact probably related to the differences in film growth.
Review paper: Principles and Applications of Surface Analytical Techniques at the Vascular Interface
Authors: Kannan Ruben Y. , Salacinski Henryk J. , Vara Dina S. , Odlyha Marianne , Seifalian Alexander M.
Published: July 2006

Surface properties have been found to be one of the key parameters which cause degradation and of thrombogenicity in all polymers used in biomedical devices, thus signifying the importance and the necessity for quantitative and accurate characterization of the polymer surface itself as used in the construction of the device. The characterization techniques employed generally involve thermal and spectroscopic measurements, in which class the electrochemical investigations and scanning probe microscopies can also be included. Current hypotheses on the correlations that exist between surface parameters and hemocompatibility and degradation of polymers are examined herein, but concentrating on the field of clinically utilized polymeric materials as used within medical devices themselves. Furthermore, this review provides a brief but complete synopsis of these techniques and other emerging ones, which have proven useful in the analysis of the surface properties of polymeric materials as used in the construction of cardiovascular devices. Statements and examples are given as to how specific information can be acquired from these differing methodologies and how it aids in the design and development of new polymers for usage in biomedical device construction.
Recruiting and Retaining Students in Family and Consumer Sciences Education: El Puente Para El Futuro (The Bridge to the Future) Mentoring Project
Authors: Eastman Wanda A. , Cummings Merrilyn N. , Petersen Garlene , VanLeeuwen Dawn
Published: July 2006

El Puente Para El Futuro (The Bridge to the Future) mentoring project was undertaken to meet the need for family and consumer sciences (FCS) teachers. The centerpiece of the project was one‐on‐one mentoring relationships between family and consumer sciences education (FCSE) mentor students from New Mexico State University and mentee students from the Education Program at Dona Ana Branch Community College. During fall 2003, the researchers developed curricula, recruitment materials, and assessment instruments. Seven mentor‐mentee pairs completed the project during spring 2004. The researchers planned monthly structured events, and each mentor‐mentee pair arranged for unstructured events. Valid and reliable cognitive and affective assessments were administered to participants at the beginning and end of the project. Mentees had significant increases in both cognitive and affective mean scores regarding teaching FCS. This mentoring model is recommended to FCSE educators and others working in recruitment settings.
Self‐Concepts and Self‐Worth as Predictors of Self‐Perception of Morality: Implications for Delinquent Risk Behavior Associated With Shoplifting
Authors: Forney William Scott , Crutsinger Christy , Forney Judith Cardona
Published: July 2006

This study examined delinquent risk behavior defined as shoplifting involvement from a social domain perspective. Aspects of adolescent self‐concepts associated with significant others and self‐worth were explored as predictors of self‐perception of morality. The sample (N = 155) comprised Caucasian students aged 14 to 18 enrolled in one high school in a Southwest state. More than half of the adolescents had self‐reported shoplifting involvement. Independent two‐step regression analyses were conducted for the two shoplifting involvement groups. Peer social acceptance was a strong positive predictor of self‐worth for adolescents with shoplifting involvement, whereas the strongest predictor for adolescents with no shoplifting involvement was parent‐child relationships. Strong direct paths linked peer social acceptance, self‐worth, and self‐perception of morality for adolescents with shoplifting involvement, and parent‐child relationships, self‐worth, and self‐perception of morality for adolescents with no shoplifting involvement. Educational implications for programs focusing on adolescent self‐concept and moral development are discussed.
Hitting the Target (or Not): Comparing Characteristics of Fatal, Injurious, and Noninjurious Police Shootings
Authors: White Michael D.
Published: July 2006

Despite the well-documented inaccuracy of police officers who use deadly force, research has generally given scant attention to factors that affect shooting accuracy. This article uses bivariate and multivariate analyses—logistic regression and chi-square automatic interaction detector (CHAID)—to examine characteristics among noninjurious, injurious, and fatal police shootings in Philadelphia from 1987 to 1992 (N = 271). A number of factors emerge as predictors of shooting accuracy including distance, suspect actions, and officer approach and preparedness. Alternatively, a number of seemingly important factors appear unrelated to shooting accuracy including lighting conditions, use of cover, and gun type. The article concludes with a discussion of findings and their implications for police policy and training.
XIAP targeting sensitizes Hodgkin lymphoma cells for cytolytic T-cell attack
Authors: Kashkar Hamid , Seeger Jens-Michael , Hombach Andreas , Deggerich Anke , Yazdanpanah Benjamin , Utermöhlen Olaf , Heimlich Gerd , Abken Hinrich , Krönke Martin
Published: July 2006

The immunosurveillance of Hodgkin lymphoma (HL) by cytotoxic T lymphocytes (CTLs) is insufficient, and the clinical experience with adoptive transfer of CTLs is limited. We have previously reported that defects in mitochondrial apoptotic pathways and elevated XIAP expression confer resistance to different apoptotic stimuli in HL cells. Here, we aimed to develop molecular strategies to overcome the resistance of HL cells against CTL-mediated killing via granzyme B (grzB). In HL cells, grzB-induced mitochondrial release of proapoptotic Smac is blocked, which results in complete abrogation of cytotoxicity mediated by CTLs. Cytosolic expression of recombinant mature Smac enhanced caspase activity induced by grzB and restored the apoptotic response of HL cells. Similarly, down-regulation of XIAP by RNA interference markedly enhanced the susceptibility of HL cells for CTL-mediated cytotoxicity. XIAP gene knockdown sensitized HL cells for killing by antigen-specific CTLs redirected by grafting with a chimeric anti-CD30scFv-CD3zeta immunoreceptor. The results suggest that XIAP targeting by Smac agonists or XIAP-siRNA can be used as a synergistic strategy for cellular immunotherapy of Hodgkin lymphoma.
Type I interferons directly regulate lymphocyte recirculation and cause transient blood lymphopenia
Authors: Kamphuis Elisabeth , Junt Tobias , Waibler Zoe , Forster Reinhold , Kalinke Ulrich
Published: July 2006

Early viral infection is often associated with lymphopenia, a transient reduction of blood lymphocyte counts long before the onset of clinical symptoms. We have investigated lymphopenia in mice infected with vesicular stomatitis virus (VSV) or treated with the Toll-like receptor (TLR) agonists poly(I:C) and R-848. In all cases analyzed, lymphopenia was critically dependent on type I interferon receptor (IFNAR) signaling. With the use of bone marrow–chimeric mice, radioresistant cells, such as stroma and endothelium, could be excluded as type I interferon (IFN-α/β) targets for the induction of lymphopenia. Instead, adoptive transfer experiments and studies in conditionally gene-targeted mice with a B- or T-cell–specific IFNAR deletion demonstrated that IFN-α/β exerted a direct effect on lymphocytes that was necessary and largely sufficient to induce lymphopenia. Furthermore, after treatment with R-848, we found that other cytokines such as TNF-α also played a role in T-cell lymphopenia. Investigation of the molecular mechanism revealed that lymphopenia was mainly independent of G protein–coupled receptors (GPCRs) and chemokines. In an adhesion assay, B cells of poly(I:C)–treated mice showed moderately increased adhesion to ICAM-1 but not to VCAM-1. In conclusion, our data identify a new effect of direct IFN-α/β stimulation of lymphocytes that profoundly affects lymphocyte redistribution.
Heterogeneity of pneumococcal phase variants in invasive human infections
Authors: Serrano I , Melo-Cristino J , Ramirez M
Published: July 2006

Background

Streptococcus pneumoniae can be carried asymptomatically in the nasopharynx of its human host but can also cause a wide range of infections. A role for pneumococcal phase variants in the different lifestyles of this bacterium has been suggested but no systematic survey of the colony phenotypes of isolates associated with human infections has been undertaken.

Results

We report the colony opacity phenotypes of a genetically diverse set of 304 invasive isolates representing 10 serotypes. Over half of the isolates (52%) presented the opaque phenotype whereas transparent variants accounted for only 26% of the total. However, the frequency of recovery of each phase variant was not uniform, while serotypes 1, 4, 12B and 23F presented the opaque phenotype more frequently than expected by chance, serotypes 3 and 14 where less frequently associated with this phenotype.

Conclusion

The opaque phenotype was the most frequent phenotype found among invasive isolates. An unexpected and equally important finding is the variability of the dominant opacity phenotype found among serotypes. This observation highlights the heterogeneity of opacity phenotypes in invasive isolates and lends further support to the proposal that other factors, in addition to the site of isolation, determine the opacity phenotype of a given isolate. The association between serotype and colonial opacity could help explain epidemiological differences observed among pneumococcal serotypes such as a higher invasive disease potential.
Unexpected death after headache due to a colloid cyst of the third ventricle
Authors: Shaktawat Sameer S , Salman Walid D , Twaij Zuhair , Al-Dawoud Abdul
Published: July 2006

Background

Colloid cysts of the third ventricle are rare benign intracranial non-neoplastic cysts. Headache is the most common symptom. We present a case of sudden death due to colloid cyst in a 17 year old female who had symptoms of intermittent headaches.

Case presentation

A 17 year old female presented with intermittent mild headaches for a period of two years. She complained of severe headache in the night and was found unresponsive the next morning. Resuscitation team was called on site but the patient was already dead. At post mortem examination a dilated ventricular system was found with a colloid cyst of the third ventricle.

Conclusion

This report highlights the difficulty in the diagnosis and importance of recognizing colloid cyst of the third ventricle which should be in the differential diagnosis of headaches in children and young adults and of hydrocephalus at autopsy
Promyelocytic leukemia nuclear bodies are predetermined processing sites for damaged DNA
Authors: Bøe Stig Ove , Haave Marte , Jul-Larsen Åsne , Grudic Amra , Bjerkvig Rolf , Lønning Per Eystein
Published: July 2006

The promyelocytic leukemia protein (PML) participates in several cellular functions, including transcriptional regulation, apoptosis and maintenance of genomic stability. A key feature of this protein is its ability to induce the assembly of nuclear compartments termed PML-nuclear bodies (PML-NBs). Here we show that these nuclear structures recruit single-stranded DNA (ssDNA) molecules in response to exogenous DNA damage. ssDNA was readily detected in PML-NBs within 1 hour following exposure of cells to UV light. Confocal real-time imaging of cells expressing YFP-tagged PML did not reveal de novo formation of new PML-NBs following UV-irradiation, which shows that ssDNA focus formation occurred within pre-existing PML-NBs. Moreover, siRNA-mediated depletion of PML prevented ssDNA focus formation and sensitized cells to UV-induced apoptosis. PML-dependent ssDNA focus formation was found to be particularly efficient during S-phase of the cell cycle, and PML-depleted cells became retarded in S-phase upon growth in the presence of etoposide. In addition, we found that caffeine and the poly(ADP-ribose) polymerase (PARP) inhibitor NU1027 enhanced UV-induced recruitment of ssDNA to PML-NBs. Together, our results show that PML-NBs have the capacity to accommodate DNA metabolic activities that are associated with processing of damaged DNA.
Palladin binds to Eps8 and enhances the formation of dorsal ruffles and podosomes in vascular smooth muscle cells
Authors: Goicoechea Silvia , Arneman Daniel , Disanza Andrea , Garcia-Mata Rafael , Scita Giorgio , Otey Carol A.
Published: July 2006

Palladin is a widely expressed phosphoprotein that plays an important role in organizing the actin cytoskeleton. Palladin is concentrated in multiple actin-based structures involved in cell motility and adhesion, including stress fibers, focal adhesions, cell-cell junctions, growth cones and Z-discs. Here, we show that palladin also localizes to the dorsal, circular ruffles that form transiently in response to growth factor stimulation. More importantly, palladin knockdown results in decreased ruffle formation and decreased Rac activation following PDGF treatment. In addition, we describe a novel interaction between palladin and Eps8, a receptor tyrosine kinase (RTK) substrate that participates in the activation of the Rac-specific guanine nucleotide-exchange function of Sos-1. Eps8 was identified as a molecular partner for palladin in a yeast two-hybrid screen, and the interaction was confirmed biochemically in co-immunoprecipitation assays. The two proteins were found to colocalize extensively in dorsal ruffles. Palladin also localizes to podosomes after phorbol ester stimulation, and palladin knockdown results in decreased podosome formation in response to PDBu. Together, these data provide strong evidence for a direct and specific interaction between palladin and Eps8, and suggest that they act together in the rapid and transient remodeling of the actin cytoskeleton, which promotes the formation of highly dynamic membrane protrusions in response to PDGF and phorbol ester treatment.
Critical Phenomena in a Surfactant/Water/Oil System. Basic Study on the Correlation between Solubilization, Microemulsion, and Ultralow Interfacial Tensions
Authors: Kunieda Hironobu , Friberg Stig E
Published: July 2006

The phase equilibrium in C8H17(OCH2CH2)3OH/water/decane system was studied at 13.6, 15.8, 21.5, 26.0, and 30.0 °C. An upper critical solution point for the surfactant and oil phases, and a lower critical solution point for the surfactant and water phases were found. Strong critical opalescence was observed in the vicinity of the critical points. In a temperature range between two critical points, a three-phase region appeared due to the superposition of three miscibility gaps, i.e., 1) surfactant+water; 2) surfactant+oil, and 3) oil+water phases. The correlations between the phase equilibria and the ultralow interfacial tensions were straightforward. An ionic surfactant/cosurfactant/brine/oil system gave similar phase equilibria as the nonionic surfactant system, but the effect of temperature was the reverse.
Transport Number of Ions in Water/DMF Solvents and Reference Electrode for Electrochemical Measurements in Nonaqueous Media
Authors: Takaoka Kazunori , Bates Roger G
Published: July 2006

The transport number of the ions, t±, of (C2H5)4NClO4, NaClO4, NaCl, KCl, and HCl in N,N-dimethylformamide(DMF)–water solvents were determined by the agar–salt bridge method. In order to compare this method, t+(HCl)’s in DMF–water media were measured by both the Hittorf method and the concentration cell method. Good agreement among these methods leads to the conclusion that t+(KCl) and t−(KCl) are nearly equal in the whole range of DMF–water media. The results suggest that potentials obtained in nonaqueous polarography with the bridged SCE by correcting the bridge potential with a slow flowing type aqueous SCE are always referred to the ordinary aqueous SCE.
The Crystal Structure and Luminescence Properties of Europium(II) Haloborates
Authors: Machida Ken-ichi , Adachi Gin-ya , Moriwaki Yoshikazu , Shiokawa Jiro
Published: July 2006

The crystal structures of Eu2B5O9X (X=Cl and Br) were determined by the method of X-ray diffraction analysis and refined by the least-square method to give R=0.054 for 1967 observed reflections of Eu2B5O9Cl and R=0.047 for 1979 observed reflections of Eu2B5O9Br. These haloborates are isostructural and belong to the orthorhombic (pseudotetragonal) system, with the Pnn2 space group and with four formula units in a cell of those dimensions: a=11.364(3), b=11.301(3), and c=6.504(2) Å for Eu2B5O9Cl, and a=11.503(3), b=11.382(3), and c=6.484(2) Å for Eu2B5O9Br. The structure consists of a three-dimensional (B5O9)∞ network, the B5O12 groups of three BO4 tetrahedra and two BO3 triangles being linked together with one another. The Eu and X atoms are located alternately in tunnels of the (B5O9)∞ network extending along the c axis. Each Eu atom is surrounded by two X atoms and seven O atoms, and is isolated from the neighboring Eu atoms attributable to borate units and X atoms. This arrangement of anions around Eu atoms relates to the fact that the Eu2+-activated phosphors of alkaline earth analogs give emissions with a high quantum efficiency.
The Crystal Structure and Magnetic Property of Europium(II) Orthoborate
Authors: Machida Ken-ichi , Adachi Gin-ya , Hata Hajime , Shiokawa Jiro
Published: July 2006

The europium(II) orthoborate Eu3(BO3)2 is trigonal, space group R\bar3c, with a=9.069(1), c=12.542(2) Å and Z=6. The structure has been refined to R=0.082 for 259 observed reflections with isotropic thermal parameters. The borate contains isolated and planar triangle BO33− ions, the anions and Eu atoms being hexagonally packed along c. Each Eu atom is surrounded by 8 oxygens with Eu–O distances varying from 2.36 to 2.95 Å. The interatomic distances between Eu atoms are 3.509–4.200 Å for 8 nearest Eu neighbors and 4.831–5.450 Å for 6 second-nearest Eu neighbors. The 6 nearest Eu neighbors with the interatomic distances of 3.509 and 3.778 Å and the 4 second-nearest Eu neighbors with the Eu–O–Eu angle of 166.0° are effective for the magnetic exchange and superexchange interactions between Eu2+ ions, giving rise to ferromagnetism at low temperature.
Optical Resolution and Circular Dichroism Spectra of Mixed-diamine Palladium(II) Complexes with Configurational Chirality
Authors: Nakayama Kazuhiko , Komorita Takashi , Shimura Yoichi
Published: July 2006

Six square-planar complexes, [PdL(meso-stien)](ClO4)2 (meso-stien=meso-1,2-diphenyl-1,2-ethanediamine; L=N,N-diethylethylenediamine, N,N-dimethylethylenediamine, 2-methyl-1,2-propanediamine, N2,N2-dimethyl-2-methyl-1,2-propanediamine, N, N-dimethyl-1,3-propanediamine, and (2S)-N1,N1diethyl-1,2-propanediamine), were prepared and optically resolved (or separated in the case of the last named ligand) using diacetyl-d-tartaric anhydride as the resolving agent. Their electronic absorption and CD spectra were measured. A definite additivity has been confirmed between the configurational CD caused by the chiral configuration and the vicinal CD due to the asymmetric carbon atom in the (2S)-N1,N1-diethyl-1,2-propanediamine complex. Absolute configurations of this and the other five complexes have been assigned by examining molecular models and the CD spectra.
Binuclear Metal Complexes. XXXVII. Crystal and Molecular Structure of a Binuclear Manganese(III) Complex Bridged by Two Alkoxo Oxygens and Two Bidentate Acetate Ions
Authors: Mikuriya Masahiro , Torihara Naoyuki , Okawa Hisashi , Kida Sigeo
Published: July 2006

The crystal structure of binuclear manganese(III) complex, Mn(spa)(ac) (H2spa=3-salicylideneamino-1-propanol, ac=acetate), was determined by the single-crystal X-ray diffraction method. The crystals are triclinic, space group P\bar1, a=8.804(3), b=9.376(3), c=8.671(3) Å, α=111.24(3), β=101.34(3), γ=65.00(3)°, and Z=1. The structure was solved by the heavy atom method and refined by the block-diagonal least-squares method to an R factor of 0.034. The crystal structure consists of discrete binuclear clusters, where the two manganese atoms are bridged by two alkoxo oxygens of the spa ligands and two bidentate acetate ions. The structural detail is in conformity with the magnetic and spectral properties previously reported.
X-Ray Structures of Cu(II) Chelates of cis-1,3-Cyclohexanediamine
Authors: Kamisawa Keiko , Matsumoto Keiji , Ooi Shun’ichiro , Saito Reiko , Kidani Yoshinori
Published: July 2006

The crystal structures of wine-red [Cu(1,3-chxn)2]Br2 (1), [Cu(1,3-chxn)2](NO3)2 (2), and blue-violet [CuCl(1,3-chxn)2]ClO4 (3) (1,3-chxn=cis-1,3-cyclohexanediamine) have been determined from the diffractometer data measured by the use of Mo Kα radiation. The structures were solved by the Patterson–Fourier method and refined by the least-squares method to R=0.042 (1), 0.033 (2), and 0.057 (3) for 1309, 1210, and 776 nonzero reflections respectively. The Cu atoms in 1 and 2 have a square-planar coordination by 4 N atoms, while the complex ion in 3 has a 5-coordinate square-pyramidal geometry, with the Cl atom at the apical position. The 6-membered chelate rings in 1, 2, and 3 are of the chair, flattened-chair, and envelope conformations respectively. The complex ions in 1 and 2 have virtually a C2h symmetry, the two-fold axis of which lies on the CuN4 plane. The virtual symmetry for [CuCl(1,3-chxn)2]+ is C2v, the approximate two-fold axis being coincident with the Cu–Cl bond. The cyclohexane rings (chair conformation) in 2 and 3 are roughly perpendicular to the coordination plane, but that in 1 leans toward the central Cu(II) atom. The formation of such coordinatively unsaturated Cu(II) complexes as 1–3 is attributable to the steric hindrance of the bulky cyclohexane ring to the axial coordination site.
Reaction Paths of the Photochemical Electrocyclic Reaction of Acrylaldehyde. A Possible Path via a Zwitterion
Authors: Kikuchi Osamu , Kubota Hiroshi , Suzuki Keizo
Published: July 2006

The photochemical electrocyclic reaction paths of s-cis-acrylaldehyde to oxetene were examined on the basis of the potential surfaces obtained by the MINDO/3 CI calculation, and compared with those of the corresponding conjugated hydrocarbon system. The strong S0-S2 interaction, which appears in the disrotatory mode of the cyclization of butadiene, was not observed in the acrylaldehyde–oxetene system. There appears to be a step-by-step path, in which the π→π* induced rotation of the methylene group is followed by the ring-closing step. The zwitterion in which the positive charge is localized on the terminal carbon atom is involved in this step. Since the σ lone-pair electrons of the oxygen atom play a key role in the ring-closing step, this path is characteristic of the hetero-atom conjugated system and cannot be deduced by analogy or by a simple extension of the concepts established for the photoreactions of all-hydrocarbon conjugated systems. The possible decay paths from acrylaldehyde in the excited states were also discussed.
Dehydrooligopeptides. II. The Synthesis of Dehydrodehydrodipeptides by Direct Coupling and Base-catalyzed β-Elimination
Authors: Shin Chung-gi , Yonezawa Yasuchika , Takahashi Masatoshi , Yoshimura Juji
Published: July 2006

The direct coupling between N-protected α-dehydroamino acid (1) and N-free α-dehydroamino acid ester (2) by the acid-chloride method was carried out to give several dehydrodehydrodipeptides (7). Furthermore, the two kinds of dehydrodipeptides with a hydroxyl group, obtained by the coupling of 1 with a serine or threonine ester, and that of N-protected serine or threonine with 2, followed by mesylation and subsequent base-catalyzed β-elimination gave a number of 7 substances in good yields. The configurational structures of 7 obtained by both direct condensation and elimination were found to have (Z,Z)-geometry.
The Preparation of Optically Active β-Keto Sulfoxides by Means of an Enantiomer-differentiating Reaction of α-Lithio Aryl Methyl Sulfoxides with Chiral Carboxylates
Authors: Kunieda Norio , Suzuki Akira , Kinoshita Masayoshi
Published: July 2006

The reaction of α-lithio aryl methyl sulfoxides with a limited amount of chiral carboxylates (R2–CO–O–R*) was found to be an enantiomer-differentiating reaction, affording the corresponding optically active β-keto sulfoxides (3), together with optically active aryl methyl sulfoxides which have the opposite configuration. The optical purity and the predominant configuration of 3 obtained were assigned by means of a combination of polarimetric analysis and NMR. The degree of enantioselectivity of this reaction was affected by the nature of the ester moiety R2, indicating an increase in optical yields, from 1.3%, where R2 was ethyl (3b), to 70.3%, where R2 was t-butyl (3f). The stereochemical course of the reaction has been discussed by considering a six-membered cyclic transition state. Furthermore, the repeated recrystallizations of several β-keto sulfoxides thus obtained, such as (−)-3e, (−)-3f, (−)-3g, and (−)-3p, were found to give the corresponding highly optically pure β-keto sulfoxides.
Crystal Structure and Absolute Configuration of (−)589-Tris(2,2′-bipyridinecobalt(III) Hexacyanoferrate(III) Octahydrate
Authors: Yanagi Kazunori , Ohashi Yuji , Sasada Yoshio , Kaizu Youkoh , Kobayashi Hiroshi
Published: July 2006

The crystal structure and absolute configuration of the title compound, (−)589-[Co(bpy)3][Fe(CN)6]·8H2O, has been determined from single-crystal X-ray data. The yellow crystals are triclinic; unit-cell dimensions a=12.174(3), b=16.742(7), c=10.651(3) Å, α=103.25(3), β=104.09(2), γ=94.71(3)°, space group Pl, Z=2. The structure was solved by the heavy-atom method and refined to R=0.076. The (−)589-isomer of [Co(bpy)3]3+ has Δ configuration. The [Co(bpy)3]3+ and [Fe(CN)6]3− ions have an approximate D3 symmetry and nearly the same structure as those in other related complexes. All the N atoms in [Fe(CN)6]3− and the water molecules participate in a three-dimensional hydrogen-bond network.