bluuebunny/crossref_metadata_2025 huggingface dataset:
REST/NRSF governs the expression of dense-core vesicle gliosecretion in astrocytes
Authors: Prada Ilaria , Marchaland Julie , Podini Paola , Magrassi Lorenzo , D'Alessandro Rosalba , Bezzi Paola , Meldolesi Jacopo
Published: May 2011

Astrocytes are the brain nonnerve cells that are competent for gliosecretion, i.e., for expression and regulated exocytosis of clear and dense-core vesicles (DCVs). We investigated whether expression of astrocyte DCVs is governed by RE-1–silencing transcription factor (REST)/neuron-restrictive silencer factor (NRSF), the transcription repressor that orchestrates nerve cell differentiation. Rat astrocyte cultures exhibited high levels of REST and expressed neither DCVs nor their markers (granins, peptides, and membrane proteins). Transfection of a dominant-negative construct of REST induced the appearance of DCVs filled with secretogranin 2 and neuropeptide Y (NPY) and distinct from other organelles. Total internal reflection fluorescence analysis revealed NPY–monomeric red fluorescent protein–labeled DCVs to undergo Ca2+-dependent exocytosis, which was largely prevented by botulinum toxin B. In the I–II layers of the human temporal brain cortex, all neurons and microglia exhibited the expected inappreciable and high levels of REST, respectively. In contrast, astrocyte REST was variable, going from inappreciable to high, and accompanied by a variable expression of DCVs. In conclusion, astrocyte DCV expression and gliosecretion are governed by REST. The variable in situ REST levels may contribute to the well-known structural/functional heterogeneity of astrocytes.
Effects of Long‐term Parenteral Nutrition on Serum Lipids, Plant Sterols, Cholesterol Metabolism, and Liver Histology in Pediatric Intestinal Failure
Authors: Kurvinen Annika , Nissinen Markku J. , Gylling Helena , Miettinen Tatu A. , Lampela Hanna , Koivusalo Antti I. , Rintala Risto J. , Pakarinen Mikko P.
Published: May 2011

Background and Objective:

Plant sterols (PS) in parenteral nutrition (PN) may contribute to intestinal failure–associated liver disease. We investigated interrelations between serum PS, liver function and histology, cholesterol metabolism, and characteristics of PN.

Patients and Methods:

Eleven patients with intestinal failure (mean age 6.3 years) receiving long‐term PN were studied prospectively (mean 254 days) and underwent repeated measurements of serum lipids, noncholesterol sterols, including PS, and liver enzymes. PS contents of PN were analyzed. Liver biopsy was obtained in 8 patients. Twenty healthy children (mean age 5.7 years) served as controls.

Results:

Median percentage of parenteral energy of total daily energy (PN%) was 48%, including 0.9 g · kg−1 · day−1 of lipids. Respective amounts of PN sitosterol, campesterol, avenasterol, and stigmasterol were 683, 71, 57, and 45 μg · kg−1 · day−1. Median serum concentrations of sitosterol (48 vs 7.5 μmol/L, P < 0.001), avenasterol (2.9 vs 1.9, P < 0.01), stigmasterol (1.9 vs 1.2, P < 0.005), but not that of campesterol (9.8 vs 12, P = 0.22), were increased among patients in relation to controls, and correlated with PN% (r = 0.81–0.88, P < 0.005), but not with PN fat. Serum cholesterol precursors were higher in patients than in controls. Serum liver enzymes remained close to normal range. Glutamyl transferase correlated with serum PS (r = 0.61–0.62, P < 0.05). Liver fibrosis in 5 patients reflected increased serum PS (r = 0.55–0.60, P = 0.16–0.12).

Conclusions:

Serum PS moderately increase during olive oil–based PN, and correlate positively with PN% and glutamyl transferase. Despite well‐preserved liver function, histology often revealed significant liver damage.
Moment isotropy and discrete rotational symmetry of two-dimensional lattice vectors
Authors: Chen Hudong , Orszag Steven
Published: May 2011

We present a direct proof of a theorem linking the order of moment isotropy and degree of discrete rotational symmetry for a two-dimensional set of lattice vectors. This theorem has been proved previously based on properties of sinusoidal functions. The new proof is based instead on purely linear algebraic arguments.
Convergence of a three-dimensional quantum lattice Boltzmann scheme towards solutions of the Dirac equation
Authors: Lapitski Denis , Dellar Paul J.
Published: May 2011

We investigate the convergence properties of a three-dimensional quantum lattice Boltzmann scheme for the Dirac equation. These schemes were constructed as discretizations of the Dirac equation based on operator splitting to separate the streaming along the three coordinate axes, but their output has previously only been compared against solutions of the Schrödinger equation. The Schrödinger equation arises as the non-relativistic limit of the Dirac equation, describing solutions that vary slowly compared with the Compton frequency. We demonstrate first-order convergence towards solutions of the Dirac equation obtained by an independent numerical method based on fast Fourier transforms and matrix exponentiation.
Simultaneous incorporation of mass and force terms in the multi-relaxation-time framework for lattice Boltzmann schemes
Authors: Kuzmin A. , Guo Z. L. , Mohamad A. A.
Published: May 2011

This paper presents an analysis of the simultaneous incorporation of force and mass source terms into the multi-relaxation-time (MRT) collision operator. MRT force incorporation was obtained through Chapman–Enskog analysis. The numerical scheme was tested on different benchmark problems, including the decay of a shear wave with different bulk and kinematic viscosities and axisymmetric flow.
Viscously damped acoustic waves with the lattice Boltzmann method
Authors: Viggen Erlend Magnus
Published: May 2011

Acoustic wave propagation in lattice Boltzmann Bhatnagar–Gross–Krook simulations may be analysed using a linearization method. This method has been used in the past to study the propagation of waves that are viscously damped in time, and is here extended to also study waves that are viscously damped in space. Its validity is verified against simulations, and the results are compared with theoretical expressions. It is found in the infinite resolution limit
k
→0 that the absorption coefficients and phase differences between density and velocity waves match theoretical expressions for small values of
ωτ

ν

, the characteristic number for viscous acoustic damping. However, the phase velocities and amplitude ratios between the waves increase incorrectly with (
ωτ

ν

)
2
, and agree with theory only in the inviscid limit
k
→0,
ωτ

ν

→0. The actual behaviour of simulated plane waves in the infinite resolution limit is quantified.
Efficient lattice Boltzmann algorithm for Brownian suspensions
Authors: Mynam Mahesh , Sunthar P. , Ansumali Santosh
Published: May 2011

A lattice Boltzmann (LB)-based hybrid method is developed to simulate suspensions of Brownian particles. The method uses conventional LB discretization (without fluid- level fluctuations) for suspending fluid, and treats Brownian particles as point masses with a stochastic thermal noise. LB equations are used to compute the velocity perturbations induced by the particle motion. It is shown that this method correctly reproduces the short-time and long-time diffusive behaviour of a Brownian particle. Unlike the earlier hybrid methods that use thermal fluctuations in the fluid, this method correctly reproduces the temperature of the particle and does not require an empirical rescaling of the bare friction coefficient to obtain the correct diffusive behaviour. It is observed that the present method is at least twice as fast as the earlier method. This method is best suited for flows of polymers and Brownian suspensions in microfluidic devices.
Higher order slip according to the linearized Boltzmann equation with general boundary conditions
Authors: Lorenzani Silvia
Published: May 2011

In the present paper, we provide an analytical expression for the first- and second-order velocity slip coefficients by means of a variational technique that applies to the integrodifferential form of the Boltzmann equation based on the true linearized collision operator and the Cercignani–Lampis scattering kernel of the gas–surface interaction. The polynomial form of the Knudsen number obtained for the Poiseuille mass flow rate and the values of the velocity slip coefficients are analysed in the frame of potential applications of the lattice Boltzmann methods in simulations of microscale flows.
Matrix lattice Boltzmann reloaded
Authors: Karlin Ilya , Asinari Pietro , Succi Sauro
Published: May 2011

The lattice Boltzmann equation was introduced about 20 years ago as a new paradigm for computational fluid dynamics. In this paper, we revisit the main formulation of the lattice Boltzmann collision integral (matrix model) and introduce a new two-parametric family of collision operators, which permits us to combine enhanced stability and accuracy of matrix models with the outstanding simplicity of the most popular single-relaxation time schemes. The option of the revised lattice Boltzmann equation is demonstrated through numerical simulations of a three-dimensional lid-driven cavity.
Unstable periodic orbits in the Lorenz attractor
Authors: Boghosian Bruce M. , Brown Aaron , Lätt Jonas , Tang Hui , Fazendeiro Luis M. , Coveney Peter V.
Published: May 2011

We apply a new method for the determination of periodic orbits of general dynamical systems to the Lorenz equations. The accuracy of the expectation values obtained using this approach is shown to be much larger and have better convergence properties than the more traditional approach of time averaging over a generic orbit. Finally, we discuss the relevance of the present work to the computation of unstable periodic orbits of the driven Navier–Stokes equations, which can be simulated using the lattice Boltzmann method.
Rotational behaviour of red blood cells in suspension: a mesoscale simulation study
Authors: Janoschek F. , Mancini F. , Harting J. , Toschi F.
Published: May 2011

The nature of blood as a suspension of red blood cells makes computational haemodynamics a demanding task. Our coarse-grained blood model, which builds on a lattice Boltzmann method for soft particle suspensions, enables the study of the collective behaviour of the order of 106cells in suspension. After demonstrating the viscosity measurement in Kolmogorov flow, we focus on the statistical analysis of the cell orientation and rotation in Couette flow. We quantify the average inclination with respect to the flow and the nematic order as a function of shear rate and haematocrit. We further record the distribution of rotation periods around the vorticity direction and find a pronounced peak in the vicinity of the theoretical value for free model cells, even though cell–cell interactions manifest themselves in a substantial width of the distribution.
Evaluation of a new solid boundary implementation in the lattice Boltzmann method for porous media considering permeability and apparent slip
Authors: Moqtaderi Hamed , Esfahanian Vahid
Published: May 2011

The accuracy of solid wall treatment in the lattice Boltzmann method (LBM) simulation of porous structures affects different hydraulic parameters including integral properties, such as permeability, or local phenomena, such as apparent slip. Based on an analysis of the advantages and disadvantages of the current methods, a new technique is introduced for exact boundary extraction from binary representation. Using this technique, the LBM model can simultaneously benefit from the advantages of existing approaches, i.e. the real micro-/nanostructure obtained with X-ray computed tomography, and a reduction in the resolution requirement. To evaluate the technique, permeability and slip length on the solid walls are investigated for a porous gas diffusion layer. The results show acceptable accuracy improvement balanced with computational costs.
Confined dynamics of a single DNA molecule
Authors: Chinappi M. , De Angelis E.
Published: May 2011

The effect of a slit-like confinement on the relaxation dynamics of DNA is studied via a mesoscale model in which a bead and spring model for the polymer is coupled to a particle-based Navier–Stokes solver (multi-particle collision dynamics). The confinement is found to affect the equilibrium stretch of the chain when the bulk gyration radius is comparable to or smaller than the channel height and our data are in agreement with the (
R
g,bulk
/
h
)
1/4
scaling of the polymer extension in the wall tangential direction. Relaxation simulation at different confinements indicates that, while the overall behaviour of the relaxation dynamics is similar for low and strong confinements, a small, but significant, slowing of the far-equilibrium relaxation is found as the confinement increases.
From the Boltzmann equation to fluid mechanics on a manifold
Authors: Love Peter J. , Cianci Donato
Published: May 2011

We apply the Chapman–Enskog procedure to derive hydrodynamic equations on an arbitrary surface from the Boltzmann equation on the surface.
Lattice Boltzmann method for adiabatic acoustics
Authors: Li Yanbing , Shan Xiaowen
Published: May 2011

The lattice Boltzmann method (LBM) has been proved to be a useful tool in many areas of computational fluid dynamics, including computational aero-acoustics (CAA). However, for historical reasons, its applications in CAA have been largely restricted to simulations of isothermal (Newtonian) sound waves. As the recent kinetic theory-based reformulation establishes a theoretical framework in which LBM can be extended to recover the full Navier–Stokes–Fourier (NS) equations and beyond, in this paper, we show that, at least at the low-frequency limit (sound frequency much less than molecular collision frequency), adiabatic sound waves can be accurately simulated by the LBM provided that the lattice and the distribution function ensure adequate recovery of the full NS equations.
Infants' knowledge of their own species
Authors: Heron-Delaney Michelle , Wirth Sylvia , Pascalis Olivier
Published: May 2011

Recognition of individuals at first sight is important for social species and can be achieved by attending to facial or body information. Previous research suggests that infants possess a perceptual template for evolutionarily relevant stimuli, which may include humans, dangerous animals (e.g. snakes), but not non-dangerous animals. To be effective, such a mechanism should result in a systematic preference for attending to humans over non-dangerous animals. Using a preferential looking paradigm, the present studies investigated the nature of infants' early representation of humans. We show that 3.5- and six-month-old infants attend more to human beings than non-human primates (a gorilla or monkey) which are examplars of non-dangerous animals. This occurred when infants were presented with head or body information in isolation, as well as when both are presented simultaneously. This early preference for humans by 3.5 months of age suggests that there is a basic representation for humans, which includes both head and/or body information. However, neonates demonstrated a preference only for human faces over non-human primate faces, not for humans over non-human primates when the stimuli were presented with both head and body simultaneously. The results show that although neonates display a preference for human faces over others, preference for the human body only develops later, in the first few months of life. This suggests that infants have acquired some knowledge about the human body at 3.5 months of age that may have developed from their privileged experience with other humans in the first few months of life, rather than an innate ability to detect humans in their entirety.
Uncoupling of GTP hydrolysis from eIF6 release on the ribosome causes Shwachman-Diamond syndrome
Authors: Finch Andrew J. , Hilcenko Christine , Basse Nicolas , Drynan Lesley F. , Goyenechea Beatriz , Menne Tobias F. , González Fernández África , Simpson Paul , D'Santos Clive S. , Arends Mark J. , Donadieu Jean , Bellanné-Chantelot Christine , Costanzo Michael , Boone Charles , McKenzie Andrew N. , Freund Stefan M.V. , Warren Alan J.
Published: May 2011

Removal of the assembly factor eukaryotic initiation factor 6 (eIF6) is critical for late cytoplasmic maturation of 60S ribosomal subunits. In mammalian cells, the current model posits that eIF6 release is triggered following phosphorylation of Ser 235 by activated protein kinase C. In contrast, genetic studies in yeast indicate a requirement for the ortholog of theSBDS(Shwachman-Bodian-Diamond syndrome) gene that is mutated in the inherited leukemia predisposition disorder Shwachman-Diamond syndrome (SDS). Here, by isolating late cytoplasmic 60S ribosomal subunits fromSbds-deleted mice, we show that SBDS and the GTPase elongation factor-like 1 (EFL1) directly catalyze eIF6 removal in mammalian cells by a mechanism that requires GTP binding and hydrolysis by EFL1 but not phosphorylation of eIF6 Ser 235. Functional analysis of disease-associated missense variants reveals that the essential role of SBDS is to tightly couple GTP hydrolysis by EFL1 on the ribosome to eIF6 release. Furthermore, complementary NMR spectroscopic studies suggest unanticipated mechanistic parallels between this late step in 60S maturation and aspects of bacterial ribosome disassembly. Our findings establish a direct role for SBDS and EFL1 in catalyzing the translational activation of ribosomes in all eukaryotes, and define SDS as a ribosomopathy caused by uncoupling GTP hydrolysis from eIF6 release.
Isolation of Human Capillary Endothelial Cells from Abdominal Adipose Tissue
Authors: Springhorn Jeremy P.
Published: May 2011

INTRODUCTION

This protocol outlines a technique to isolate human capillary endothelial cells from human abdominal wall adipose tissue. The relative lack of cell-type complexity within fat tissue makes it an attractive source of endothelial cells. In addition, collaboration with a local plastic surgeon can yield significant quantities of subcutaneous adipose tissue from liposuction without the need to be on call for cadaveric or post-surgical samples.
Drosophila Aversive Olfactory Conditioning
Authors: Krashes Michael J. , Waddell Scott
Published: May 2011

INTRODUCTION

Olfactory memory paradigms have been extensively used to study memory in Drosophila since the late 1960s, and over the intervening years investigators have made a series of worthwhile changes and “tweaks” to the procedures. This protocol provides the reader with a detailed description of the aversive (odor-shock) memory assay currently used in the Waddell laboratory. It also describes the essential control assays for sensory acuity and locomotor behavior. It should be emphasized that the assays we describe work adequately in our laboratory but are also amenable to, and may be further improved, by additional adjustments.
Affinity Purification of Protein Complexes
Authors: Cristea Ileana M. , Chait Brian T.
Published: May 2011

INTRODUCTION

Knowledge of the composition of protein complexes provides key insights into their functions. Immunoaffinity purification provides an effective means for isolating protein complexes and elucidating their composition. Immunoisolation is achieved with antibodies directed either specifically against the proteins of interest or against tags that are coupled to the proteins of interest. This approach uses immunoaffinity purification on magnetic beads coated with antibodies for the rapid and efficient purification of protein complexes from cells or tissues. This protocol describes affinity purification of protein complexes using conjugated magnetic beads.
Improved Protocol for Efficient Nonviral Transfection of Premature THP-1 Macrophages: Figure 1.
Authors: Maeß Marten B. , Buers Insa , Robenek Horst , Lorkowski Stefan
Published: May 2011

INTRODUCTION

The human monocytic leukemia cell line THP-1 is a widely used model for investigating monocyte and macrophage biology. Successful transfection of THP-1 monocytes with subsequent phorbol 12-myristate 13-acetate (PMA)-induced differentiation into macrophages is not a trivial matter, because according to previous transfection protocols, cell viability is lost almost completely within 24 h of PMA treatment following transfection. This protocol constitutes an optimized version of a previously published protocol by our group. It describes a procedure for transfecting premature THP-1 macrophages, which subsequently can be further differentiated into mature macrophages by PMA without a loss of cell viability. Transfection of THP-1 cells with plasmids or small interfering RNA (siRNA) is achieved by electroporation using the Lonza Nucleofector technology (Basel, Switzerland). This technique allows for the efficient nonviral delivery of plasmids, DNA, RNA, or siRNA into primary cells or cell lines even if the cells are not or are only slowly proliferating. Such cells are usually rather difficult to transfect by nonviral approaches. This means that only viral approaches would be left, which are expensive and labor-intensive and require laboratories complying with the respective safety regulations. The protocol described here is an efficient and convenient alternative.
Labeling Membranes with Fluorescent Phosphatidylethanolamine
Authors: Chazotte Brad
Published: May 2011

INTRODUCTION

The phospholipid phosphatidylethanolamine (PE) can be conjugated via its head group to a number of fluorophores, including rhodamine, BODIPY (boron-dipyrromethene; 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene), and NBD (N-(7-nitrobenz-2-oxa-1,3-diazole-4-yl)). These probes can be used to label biological membranes and to study phospholipids within membranes. Rhodamine-PE, which does not readily exchange between lipid bilayers, has also been used in membrane fusion assays. Rhodamine-DHPE (lissamine rhodamine B 1,2-dihexyldecanoyl-sn-glycero-3-phosphoethanolamine, triethylammonium salt) and NBD-PE have been used together in resonance energy transfer studies in membranes. This protocol describes the labeling of membranes with fluorescent PE.
Labeling the Plasma Membrane with TMA-DPH
Authors: Chazotte Brad
Published: May 2011

INTRODUCTION

TMA-DPH (trimethylamine-diphenylhexatriene) is a fluorescent membrane probe that has classically been used to label the outer leaflet of a membrane bilayer, to label the outer leaflet of the plasma membrane in cells, and to report on membrane dynamics using the techniques of fluorescence polarization and/or fluorescence lifetime. This probe has also been used to follow exocytosis and endocytosis of labeled plasma membranes. The interaction of the aqueous environment with mitochondrial inner membrane dynamics has also been studied following the fluorescence polarization and the lifetime of TMA-DPH. This protocol describes the use of TMA-DPH to label the plasma membrane.
Fluorescent Speckle Microscopy
Authors: Cameron Lisa A. , Houghtaling Benjamin R. , Yang Ge
Published: May 2011

INTRODUCTION

Fluorescent speckle microscopy (FSM) is a live imaging and quantitative measurement technique used for analyzing motion and turnover of macromolecular assemblies in vivo and in vitro. It differs from related imaging techniques such as photobleaching and photoactivation in its use of substantially lower concentrations of fluorescently labeled assembly subunits. When small numbers of labeled subunits and large numbers of unlabeled subunits become randomly incorporated together into a macromolecular structure, the random distribution of fluorophores generates nonuniform fluorescence intensity patterns that appear as distinct puncta against low background fluorescence. These puncta, called speckles, serve as fiduciary markers so that motion and turnover of the structure are visualized. Computational analysis of speckle image data transforms FSM into a powerful tool for high-resolution quantitative analysis of macromolecular assembly dynamics. Successful application of FSM depends on the ability to reliably generate and image speckles, which are characterized by their weak emission signals, and to effectively extract quantitative information through computational analysis of speckle image data, which are characterized by their stochastic fluctuations, low signal-to-noise ratios, and high spatiotemporal complexity. This article aims to provide a practical introduction to basic principles, experimental implementation, and computational data analysis of FSM. Examples are used to show the application of FSM in analyzing the dynamic organization and assembly/disassembly of cytoskeletal filament networks, an area in which FSM analysis has found great success.
Imaging Kidney Development
Authors: Costantini Frank , Watanabe Tomoko , Lu Benson , Chi Xuan , Srinivas Shankar
Published: May 2011

INTRODUCTION

Development of the kidney involves interactions between several cell lineages and complex morphogenetic processes, such as branching of the ureteric bud (UB) to form the collecting duct system and condensation and differentiation of the mesenchymal progenitors to form the nephron epithelia. One of the advantages of the mouse kidney as an experimental system is that it can develop in culture, from the stage of initial branching of the UB (E11.5) for up to a week (although it achieves the size and degree of development of only an E13.5–E14.5 kidney in vivo). The availability of fluorescent proteins (FPs) has provided powerful tools for visualizing the morphogenesis of specific renal structures in organ cultures. Two categories of genetically modified mice that express FPs are useful for visualizing different cell lineages and developmental processes in these organ cultures: (1) transgenic mice that express a fluorescent reporter in the pattern of a specific gene; and (2) Cre reporter mice, which turn on an FP in cells with Cre recombinase activity (and their daughter cells), used in conjunction with cell type-specific Cre transgenic mice. Here, we describe some of the currently available Cre and FP transgenic lines that are useful for the study of kidney development.
Analysis of Affymetrix ChIP-Chip Data Using Starr and R/Bioconductor
Authors: Zacher Benedikt , Torkler Phillipp , Tresch Achim
Published: May 2011

INTRODUCTION

This article provides a flexible workflow for the analysis of chromatin immunoprecipitation data (ChIP-chip) that covers issues from quality control, probe sequence remapping, data preprocessing/normalization, visualization, and high-level analysis like peak finding. It emphasizes the peculiarities of single-color Affymetrix arrays, but it is flexible enough to be also amenable to other array platforms. The article is accompanied by extensive code implementing each of the analysis steps.
Two-Photon Mapping of Neural Circuits
Authors: Nikolenko Volodymyr , Fino Elodie , Yuste Rafael
Published: May 2011

INTRODUCTION

For the study of neural circuits, it would be ideal to be able to discern in a living preparation the interconnections among neurons. Working toward that aim, we have developed a method, using two-photon uncaging of glutamate in brain slices, by which we can detect neurons that are presynaptic to any particular cell. The method, described here, has single-cell resolution and can be applied systematically and quickly to test entire populations of neurons, making it possible to perform online functional analysis of connectivity.
How to manage hypertension in pregnancy effectively
Authors: Magee Laura A. , Abalos Edgardo , von Dadelszen Peter , Sibai Baha , Easterling Tom , Walkinshaw Steve ,   for the CHIPS Study Group
Published: May 2011

The hypertensive disorders of pregnancy (HDP) are a leading cause of maternal mortality and morbidity in both well and under‐resourced settings. Maternal, fetal, and neonatal complications of the HDP are concentrated among, but not limited to, women with pre‐eclampsia. Pre‐eclampsia is a systemic disorder of endothelial cell dysfunction and as such, blood pressure (BP) treatment is but one aspect of its management. The most appropriate BP threshold and goal of antihypertensive treatment are controversial. Variation between international guidelines has more to do with differences in opinion rather than differences in published data. For women with severe hypertension [defined as a sustained systolic BP (sBP) of ≥160 mmHg and/or a diastolic BP (dBP) of ≥110 mmHg], there is consensus that antihypertensive therapy should be given to lower the maternal risk of central nervous system complications. The bulk of the evidence relates to parenteral hydralazine and labetalol, or to oral calcium channel blockers such as nifedipine capsules. There is, however, no consensus regarding management of non‐severe hypertension (defined as a sBP of 140–159 mmHg or a dBP of 90–109 mmHg), because the relevant randomized trials have been underpowered to define the maternal and perinatal benefits and risks. Although antihypertensive therapy may decrease the occurrence of BP values of 160–170/100–110 mmHg, therapy may also impair fetal growth. The potential benefits and risks do not seem to be associated with any particular drug or drug class. Oral labetalol and methyldopa are used most commonly, but many different β‐adrenoceptor blockers and calcium channel blockers have been studied in clinical trials.
Autoimmune cytopenia in chronic lymphocytic leukaemia: diagnosis and treatment
Authors: Hodgson Kate , Ferrer Gerardo , Pereira Arturo , Moreno Carol , Montserrat Emili
Published: May 2011

Autoimmune cytopenia, especially autoimmune haemolytic anaemia (AIHA), appears in 5–10% of patients with chronic lymphocytic leukaemia (CLL). In these patients, the prognosis is not as poor as in those cases in which the cytopenia is due to a massive bone marrow infiltration by the disease, and their treatment requires special considerations. For these reasons, the diagnosis of autoimmune cytopenia should be entertained in any patient with CLL presenting with cytopenia. In patients with autoimmune cytopenia and CLL, treatment is as for idiopathic autoimmune cytopenia, with most patients responding to corticosteroids. For patients not responding to corticosteroids, splenectomy is a reasonable treatment choice. Monoclonal antibodies and thrombopoietin analogues have shown enough activity to support their use, especially within clinical studies, in selected cases not responding to corticosteroids and before splenectomy. In patients with resistant immune cytopenia, the most effective treatment is that of the underlying CLL. Fear of fludarabine‐associated AIHA is no longer appropriate in the age of chemo‐immunotherapy. Finally, prospective studies are required to better identify the optimal therapy for these patients.
Acquisition of VanB‐type vancomycin resistance by Bacillus subtilis: the impact on gene expression, cell wall composition and morphology
Authors: Bisicchia Paola , Bui Nhat Khai , Aldridge Christine , Vollmer Waldemar , Devine Kevin M.
Published: May 2011

The vancomycin resistance operons from Enterococci, Staphylococci and Actinomycetes encode a VanRS two‐component signal transduction system (TCS) and a suite of enzymes to modify the peptidoglycan biosynthetic precursor lipid II and to eliminate the d‐Ala‐d‐Ala from the cell. Commingling of these regulatory and enzymatic activities with host functions has the potential to significantly impact host gene expression and cell wall metabolism. Here we report the effects of individually expressing the VanRBSB TCS and the VanYBWHBBXB resistance proteins in Bacillus subtilis. VanYBWHBBXB expression confers resistance to 2 µg ml−1 of vancomycin with concomitant reduced Van‐FL staining and leads to a cell division defect. In contrast to E. faecalis and S. aureus, VanSB is active in B. subtilis without vancomycin addition. Individual expression of the VanRBSB TCS and the VanYBWHBBXB resistance proteins repress and increase, respectively, expression of PhoPR regulon genes in the phosphate‐limited state. When vancomycin‐resistant cells are exposed to elevated vancomycin levels, mutant strains with increased resistance to vancomycin and a growth dependency on vanYBWHBBXB expression frequently arise. Mutation of the endogenous Ddl ligase is the necessary and sufficient cause of both phenotypes. We discuss how these effects may influence establishment of van operons in new host bacteria.
Effects of immunization with the rNfa1 protein on experimental Naegleria fowleri‐PAM mice
Authors: LEE Y. J. , KIM J. H. , SOHN H. J. , LEE J. , JUNG S. Y. , CHWAE Y. J. , KIM K. , PARK S. , SHIN H. J.
Published: May 2011

Free‐living Naegleria fowleri causes primary amoebic meningoencephalitis (PAM) in humans and animals. To examine the effect of immunization with Nfa1 protein on experimental murine PAM because of N. fowleri, BALB/c mice were intra‐peritoneally or intra‐nasally immunized with a recombinant Nfa1 protein. We analysed Nfa1‐specific antibody and cytokine induction, and the mean survival time of infected mice. Mice immunized intra‐peritoneally or intra‐nasally with rNfa1 protein developed specific IgG, IgA and IgE antibodies; the IgG response was dominated by IgG1, followed by IgG2b, IgG2a and IgG3. High levels of the Th1 cytokine, IFN‐γ, and the regulatory cytokine, IL‐10, were also induced. The mean survival time of mice immunized intra‐peritoneally with rNfa1 protein was prolonged compared with controls, (25·0 and 15·5 days, respectively). Similarly, the mean survival time of mice immunized intra‐nasally with rNfa1 protein was 24·7 days, compared with 15·0 days for controls.
Reactive oxygen species‐dependent necroptosis in Jurkat T cells induced by pathogenic free‐living Naegleria fowleri
Authors: SONG K.‐J. , JANG Y. S. , LEE Y. A. , KIM K. A. , LEE S. K. , SHIN M. H.
Published: May 2011

Naegleria fowleri, a free‐living amoeba, is the causative pathogen of primary amoebic meningoencephalitis in humans and experimental mice. N. fowleri is capable of destroying tissues and host cells through lytic necrosis. However, the mechanism by which N. fowleri induces host cell death is unknown. Electron microscopy indicated that incubation of Jurkat T cells with N. fowleri trophozoites induced necrotic morphology of the Jurkat T cells. N. fowleri also induced cytoskeletal protein cleavage, extensive poly (ADP‐ribose) polymerase hydrolysis and lactate dehydrogenase (LDH) release. Although no activation of caspase‐3 was observed in Jurkat T cells co‐incubated with amoebae, intracellular reactive oxygen species (ROS) were strongly generated by NADPH oxidase (NOX). Pretreating cells with necroptosis inhibitor necrostatin‐1 or NOX inhibitor diphenyleneiodonium chloride (DPI) strongly inhibited amoeba‐induced ROS generation and Jurkat cell death, whereas pan‐caspase inhibitor z‐VAD‐fmk did not. N. fowleri‐derived secretory products (NfSP) strongly induced intracellular ROS generation and cell death. Necroptotic effects of NfSP were effectively inhibited by pretreating NfSP with proteinase K. Moreover, NfSP‐induced LDH release and intracellular ROS accumulation were inhibited by pretreating Jurkat T cells with DPI or necrostatin‐1. These results suggest that N. fowleri induces ROS‐dependent necroptosis in Jurkat T cells.
PutativeMalasseziadermatitis in six goats
Authors: Eguchi‐Coe Yuko , Valentine Beth A. , Gorman Elena , Villarroel Aurora
Published: May 2011

Histopathology submissions from 28 goats with dermatological disease were identified in an archival search of pathology files. Microscopic sections of skin biopsy specimens were examined for the presence ofMalasseziaspp. organisms. Six cases with manyMalasseziayeasts were identified histopathologically. Based on the extent of clinical disease, three cases were regarded as localized and three were generalized infections. Clinical findings included alopecia with dry seborrhoea (four cases), greasy seborrhoea (one case), and no clinical findings specific to localizedMalasseziainfection when concurrent bacterial infection was present (one case). Mild pruritus was reported in two cases of generalized infection. No breed predilection was apparent. Three cases were male and three were female.Malasseziadermatitis occurred in goats from 10 months to 13 years of age. Three of six cases had concurrent bacterial infection. Skin lesions resolved following topical antifungal therapy in the two goats that were treated. Histopathological findings in all cases were severe follicular and epidermal orthokeratotic hyperkeratosis with minimal epithelial change and mild superficial perivascular to interstitial nonsuppurative inflammation. Numerous budding yeasts were visible within the stratum corneum of all cases; however,Malasseziawas not isolated in the three cases in which culture was attempted. Based upon these findings, the authors suggest that the diagnosisMalasseziadermatitis in goats is most likely to be made by cytological examination of skin impressions or by examination of skin biopsy samples.
Intraspecific divergence in the lateral line system in the nine‐spined stickleback (Pungitius pungitius)
Authors: TROKOVIC N. , HERCZEG G. , SCOTT McCAIRNS R. J. , IZZA AB GHANI N. , MERILÄ J.
Published: May 2011

The mechanosensory lateral line system of fishes is an important organ system conveying information crucial to individual fitness. Yet, our knowledge of lateral line diversity is almost exclusively based on interspecific studies, whereas intraspecific variability and possible population divergence have remained largely unexplored. We investigated lateral line system variability in four marine and five pond populations of nine‐spined stickleback (Pungitius pungitius). We found significant differences in neuromast number between pond and marine fish. In particular, three of seventeen lateral line regions (viz. caudal peduncle superficial neuromasts; canal neuromasts from the anterior trunk and caudal peduncle) showed strong divergence between habitats. Similar results were obtained with laboratory‐reared individuals from a subset of populations, suggesting that the patterns found in nature likely have a genetic basis. Interestingly, we also found habitat‐dependent population divergence in neuromast variability, with pond populations showing greater heterogeneity than marine populations, although only in wild‐caught fish. A comparison of neutral genetic (FST) and phenotypic (PST) differentiation suggested that natural selection is likely associated with habitat‐dependent divergence in neuromast counts. Hence, the results align with the conclusion that the mechanosensory lateral line system divergence among marine and pond nine‐spined sticklebacks is adaptive.
Attitudes and practices of healthcare providers regarding gestational diabetes: results of a survey conducted at the 2010 meeting of the International Association of Diabetes in Pregnancy Study Group (IADPSG)
Authors: Ogunyemi D. A. , Fong A. , Rad S. , Fong S. , Kjos S. L.
Published: May 2011

Diabet. Med. 28, 976–986 (2011)

Objective  To investigate the attitudes and practices of healthcare providers regarding gestational diabetes mellitus and to identify differences between provider types and geographical locations.

Research design and methods  A survey was distributed to participants at the 2010 GDM Pasadena II: International Conference regarding management of gestational diabetes.

Results  Of 250 distributed surveys, there was a 60.8% (n = 152) response rate. Most responders believed it was cost beneficial to treat and screen for gestational diabetes. Approximately 2/3 accepted that the diagnosis of Type 2 diabetes could be made in pregnancy. For the diagnosis of gestational diabetes, c. 60% opted for a one‐step screen while 30% opted for a two‐step screen. Most responders were comfortable treating a non‐pregnant woman with Type 2 diabetes. Ninety per cent of responders initiated antenatal testing at 32–34 weeks for medication‐treated gestational diabetes, with a wider variation for diet‐treated gestational diabetes. Obstetricians were less comfortable than other providers in treating a non‐pregnant woman with Type 2 diabetes, but were more likely to prescribe glyburide. Providers in the USA, compared with those from other countries, were more likely to perform a Caesarean section based on fetal weight, use glibenclamide (glyburide), initiate exercise post‐delivery and less likely to check 2‐h postprandial glucose levels. At least 80% of responders routinely screened for Type 2 diabetes at 6–12 weeks post‐delivery.

Conclusion  There are differences internationally and by provider types in attitudes and management regarding gestational diabetes. These findings may be useful in developing strategies for implementing the recent guidelines by the International Association of the Diabetes and Pregnancy Study Groups.
Fyn kinase regulates the association between amyloid precursor protein and Dab1 by promoting their localization to detergent‐resistant membranes
Authors: Minami S. Sakura , Hoe Hyang‐Sook , Rebeck G. William
Published: May 2011

J. Neurochem. (2011) 118, 879–890.

The adaptor protein Disabled1 (Dab1) interacts with amyloid precursor protein (APP) and decreases its pathological processing, an effect mediated by Fyn tyrosine kinase. Fyn is highly enriched in lipid rafts, a major site of pathological APP processing. To investigate the role of Fyn in the localization and phosphorylation of APP and Dab1 in lipid rafts, we isolated detergent‐resistant membrane (DRM) fractions from wild‐type and Fyn knock‐out mice. In wild‐type mice, all of the Fyn kinase, 17% of total APP, and 33% of total Dab1 were found in DRMs. Nearly all of the tyrosine phosphorylated forms of APP and Dab1 were in DRMs. APP and Dab1 co‐precipitated both in and out of DRM fractions, indicating an association that is independent of subcellular localization. Fyn knock‐out mice had decreased APP, Dab1, and tyrosine‐phosphorylated Dab1 in DRMs but increased co‐immunoprecipitation of DRM APP and Dab1. Expression of phosphorylation deficient APP or Dab1 constructs revealed that phosphorylation of APP increases, whereas phosphorylation of Dab1 decreases, the interaction between APP and Dab1. Consistent with these observations, Reelin treatment led to increased Dab1 phosphorylation and decreased association between APP and Dab1. Reelin also caused increased localization of APP and Dab1 to DRMs, an effect that was not seen in Fyn knock‐out neurons. These findings suggest that Reelin treatment promotes the localization of APP and Dab1 to DRMs, and affects their phosphorylation by Fyn, thus regulating their interaction.
Retinoblastoma‐independent regulation of cell proliferation and senescence by the p53–p21 axis in lamin A /C‐depleted cells
Authors: Moiseeva Olga , Bourdeau Véronique , Vernier Mathieu , Dabauvalle Marie‐Christine , Ferbeyre Gerardo
Published: May 2011

The expression of A‐type lamin is downregulated in several cancers, and lamin defects are the cause of several diseases including a form of accelerated aging. We report that depletion of lamin A/C expression in normal human cells leads to a dramatic downregulation of the Rb family of tumor suppressors and a defect in cell proliferation. Lamin A/C‐depleted cells exhibited a flat morphology and accumulated markers of cellular senescence. This senescent phenotype was accompanied by engagement of the p53 tumor suppressor and induction of the p53 target gene p21 and was prevented by small hairpin RNAs against p53, p21, or by the oncoprotein Mdm2. The expression of E2F target genes, normally required for cell cycle progression, was downregulated after lamin A/C depletion but restored after the inactivation of p53. A similar senescence response was observed in myoblasts from a patient with a lamin A mutation causing muscular dystrophy. We thus reveal a previously unnoticed mechanism of controlling cell cycle genes expression, which depends on p53 but does not require the retinoblastoma family of tumor suppressors and that can be relevant to understand the pathogenesis of laminopathies and perhaps aging.
Differential transcriptional profiles mediated by exposure to the cannabinoids cannabidiol and Δ9‐tetrahydrocannabinol in BV‐2 microglial cells
Authors: Juknat Ana , Pietr Maciej , Kozela Ewa , Rimmerman Neta , Levy Rivka , Coppola Giovanni , Geschwind Daniel , Vogel Zvi
Published: May 2011

BACKGROUND AND PURPOSE Apart from their effects on mood and reward, cannabinoids exert beneficial actions such as neuroprotection and attenuation of inflammation. The immunosuppressive activity of cannabinoids has been well established. However, the underlying mechanisms are largely unknown. We previously showed that the psychoactive cannabinoid Δ9‐tetrahydrocannabinol (THC) and the non‐psychoactive cannabidiol (CBD) differ in their anti‐inflammatory signalling pathways.

EXPERIMENTAL APPROACH To characterize the transcriptional effects of CBD and THC, we treated BV‐2 microglial cells with these compounds and performed comparative microarray analysis using the Illumina MouseRef‐8 BeadChip platform. Ingenuity Pathway Analysis was performed to identify functional subsets of genes and networks regulated by CBD and/or THC.

KEY RESULTS Overall, CBD altered the expression of many more genes; from the 1298 transcripts found to be differentially regulated by the treatments, 680 gene probe sets were up‐regulated by CBD and 58 by THC, and 524 gene products were down‐regulated by CBD and only 36 by THC. CBD‐specific gene expression profile showed changes associated with oxidative stress and glutathione depletion, normally occurring under nutrient limiting conditions or proteasome inhibition and involving the GCN2/eIF2α/p8/ATF4/CHOP‐TRIB3 pathway. Furthermore, CBD‐stimulated genes were shown to be controlled by nuclear factors known to be involved in the regulation of stress response and inflammation, mainly via the (EpRE/ARE)‐Nrf2/ATF4 system and the Nrf2/Hmox1 axis.

CONCLUSIONS AND IMPLICATIONS These observations indicated that CBD, but much less than THC, induced a cellular stress response in microglial cells and suggested that this effect could underlie its anti‐inflammatory activity.

LINKED ARTICLES This article is part of a themed section on Cannabinoids in Biology and Medicine. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2012.165.issue‐8. To view Part I of Cannabinoids in Biology and Medicine visit http://dx.doi.org/10.1111/bph.2011.163.issue‐7
In VitroElution of Amikacin and Ticarcillin from a Resorbable, Self‐Setting, Fiber Reinforced Calcium Phosphate Cement
Authors: Watts Ashlee E. , Nixon Alan J. , Papich Mark G. , Sparks Holly D. , Schwark Wayne S.
Published: May 2011

Objective:To determinein vitroelution characteristics of amikacin and ticarcillin from fiber reinforced calcium phosphate beads (FRCP).

Sample Population:Experimental.

Methods:FRCP beads with water (A), amikacin (B), ticarcillin/clavulanate (C), or both amikacin and ticarcillin/clavulanate (D) were bathed in mL phosphate‐buffered saline (PBS) at 37°C, 5% CO2and 95% room air. PBS was sampled (eluent) and beads were placed in fresh PBS at time points 1 and 8 hours and 1, 2, 3, 4, 5, 6, 7, 10, 12, 14, 18, 21, 25, 28, 35, 42, 49, and 56 days. Antibiotic concentration and antimicrobial activity of eluent againstEscherichia coli, Staphylococcus aureus, andKlebsiella pneumoniaewere determined.

Results:Both antibiotics eluted in a bimodal pattern. Beads with a single antibiotic eluted 20.8 ± 2.5% of amikacin and 29.5 ± 0.8% of ticarcillin over 56 days. Coelution of the antibiotics resulted in a lower proportion (AUC0–∞) of antibiotics eluted for both amikacin (9.5 ± 0.2%) and ticarcillin (21.7 ± 0.09%). Bioassay of antimicrobial activity of the eluent (t=1, 8, and 24 hours) established reduced antimicrobial activity of amikacin from combination beads (D).

Conclusions:FRCP beads with amikacin or ticarcillin/clavulanate, but not the combination, are suitable carriers for wound implantation.

Clinical Relevance:Duration before complete resorption of FRCP beadsin vivoshould be determined before clinical use as a resorbable depot. The results of this study underscore the importance of testing drug combinations, despite success of the combination systemically, before their use in local applications.