bluuebunny/crossref_metadata_2025 huggingface dataset:
Inhibition of Eimeria tenella CDK‐Related Kinase 2: From Target Identification to Lead Compounds
Authors: Engels Kristin , Beyer Carsten , Suárez Fernández Maria L. , Bender Frank , Gaßel Michael , Unden Gottfried , Marhöfer Richard J. , Mottram Jeremy C. , Selzer Paul M.
Published: June 2010

Apicomplexan parasites encompass several human‐ and animal‐pathogenic protozoans such as Plasmodium falciparum, Toxoplasma gondii, and Eimeria tenella. E. tenella causes coccidiosis, a disease that afflicts chickens, leading to tremendous economic losses to the global poultry industry. The considerable increase in drug resistance makes it necessary to develop new therapeutic strategies against this parasite. Cyclin‐dependent kinases (CDKs) are key molecules in cell‐cycle regulation and are therefore prominent target proteins in parasitic diseases. Bioinformatics analysis revealed four potential CDK‐like proteins, of which one—E. tenella CDK‐related kinase 2 (EtCRK2)—has already been characterized by gene cloning and expression.1 By using the CDK‐specific inhibitor flavopiridol in EtCRK2 enzyme assays and schizont maturation assays (SMA), we could chemically validate CDK‐like proteins as potential drug targets. An X‐ray crystal structure of human CDK2 (HsCDK2) served as a template to build protein models of EtCRK2 by comparative homology modeling. Structural differences in the ATP binding site between EtCRK2 and HsCDK2, as well as chicken CDK3, were addressed for the optimization of selective ATP‐competitive inhibitors. Virtual screening and “wet‐bench” high‐throughput screening campaigns on large compound libraries resulted in an initial set of hit compounds. These compounds were further analyzed and characterized, leading to a set of four promising lead compounds for development as EtCRK2 inhibitors.
Near‐lossless compression methods for spectral images
Authors: Ciprian R. , Carbucicchio M.
Published: June 2010

In this work, several near‐lossless compression methods for spectral images have been analyzed and compared. These methods are based both on the principal component analysis (PCA) and on the choice of a minimum number of spectral points, selected following different criteria. The analysis, initially carried out on 14 National Physical Laboratory tiles of certified colour, has been extended to some spectral images of paintings taken at the National Gallery of Parma (Italy). The comparison of the results with those obtained by applying the PCA analysis shows that the best method indicated as “method of a few significant points” allows reducing the spectral image size of a factor of 10 without loss of spectral and colour information. © 2010 Wiley Periodicals, Inc. Col Res Appl, 2010
Characterizing Single‐Molecule FRET Dynamics with Probability Distribution Analysis
Authors: Santoso Yusdi , Torella Joseph P. , Kapanidis Achillefs N.
Published: June 2010

Probability distribution analysis (PDA) is a recently developed statistical tool for predicting the shapes of single‐molecule fluorescence resonance energy transfer (smFRET) histograms, which allows the identification of single or multiple static molecular species within a single histogram. We used a generalized PDA method to predict the shapes of FRET histograms for molecules interconverting dynamically between multiple states. This method is tested on a series of model systems, including both static DNA fragments and dynamic DNA hairpins. By fitting the shape of this expected distribution to experimental data, the timescale of hairpin conformational fluctuations can be recovered, in good agreement with earlier published results obtained using different techniques. This method is also applied to studying the conformational fluctuations in the unliganded Klenow fragment (KF) of Escherichia coli DNA polymerase I, which allows both confirmation of the consistency of a simple, two‐state kinetic model with the observed smFRET distribution of unliganded KF and extraction of a millisecond fluctuation timescale, in good agreement with rates reported elsewhere. We expect this method to be useful in extracting rates from processes exhibiting dynamic FRET, and in hypothesis‐testing models of conformational dynamics against experimental data.
Chemistry of O‐ and H‐Containing Species on the (001) Surface of Anatase TiO2: A DFT Study
Authors: Hussain Akhtar , Gracia Jose , Nieuwenhuys Ben E. , Niemantsverdriet J. W. (Hans)
Published: June 2010

The chemistry of oxygen, hydrogen, water, and other species containing both oxygen and hydrogen atoms on the anatase TiO2 (001) surface is investigated by DFT. The adsorption energy of atoms and radicals depends appreciably on the position and mode of adsorption, and on the coverage. Molecular hydrogen and oxygen interact weakly with the clean surface. However, H2O dissociates spontaneously to give two nonidentical hydroxyl groups, and this provides a model for hydroxylation of TiO2 surfaces by water. The mobility of the hydroxyl groups created by water splitting is initially impeded by a diffusion barrier close to 1 eV. The O2 adsorption energy increases significantly in the presence of H atoms. Hydroperoxy (OOH) formation is feasible if at least two H atoms are present in the direct vicinity of O2. In the adsorbed OOH, the OO bond is considerably lengthened and thus weakened.
Stability of Gold and Platinum Nanowires on Graphite Edges
Authors: Soldano Germán José , Quaino Paola , Santos Elizabeth , Schmickler Wolfgang
Published: June 2010

The stability of coinage and noble metal nanowires supported on graphite steps is examined by density functional theory. In particular, we study the stability of supported gold and platinum wires and compare their chemical properties with those of surfaces and bare wires. A substantially stronger bond with graphite was found for platinum wires due to unfilled antibonding states, which are occupied in the case of gold. This difference has direct consequences for the adsorption of hydrogen. This reaction can occur either on the wire or directly on graphite steps. In the case of gold, the reaction is favoured on steps, while on platinum wires, it has no thermodynamical preferences. Our results suggest that, in early stages of wire formation, hydrogen could desorb gold from graphite, but not platinum.
Carbon Dioxide Capture on Amine‐Rich Carbonaceous Materials Derived from Glucose
Authors: Zhao Li , Bacsik Zoltan , Hedin Niklas , Wei Wei , Sun Yuhan , Antonietti Markus , Titirici Maria‐Magdalena
Published: June 2010

The synthesis of carbonaceous materials with a high surface density of amino functions for CO2 sorption and sequestration is reported. The amino‐rich carbonaceous materials are characterized by elemental analysis, N2 sorption, scanning and transmission electron microscopy, zeta potential, TGA and FTIR measurements. A detailed discussion on the use of these materials in CO2 capture is provided. The materials show significant sorption capabilities for CO2 (4.3 mmol g−1at −20 °C and 1 bar). Furthermore, they show a high apparent selectivity for CO2 over N2 at both low and high temperatures.
Fractional charge packet counting with constant relative resolution
Authors: Nascetti A.
Published: June 2010

A charge‐to‐digital converter concept suitable for pixel‐level charge sensitive amplifiers is presented. The circuit implements a technique referred here as fractional charge packet counting, which ensures large dynamic range operation using constant integration time. By means of a particular circuit arrangement a constant number of significant bits is provided as output, thus ensuring a constant relative resolution over the entire dynamic range.

A circuit implementing the concepts described above has been designed and simulated. Each block of the circuit is described in details and its characterization is presented. The circuit is capable to convert input currents in the range of 100 fA to 100 nA at 2 ksample/s with a constant resolution of 10 bit without the need of gain switching. Copyright © 2010 John Wiley & Sons, Ltd.
Signal processing electronics for multiple electronic and optical measurements on cells
Authors: Steinkamp John A. , Hiebert Richard D.
Published: June 2010

Processing electronics for flow cytometry applications requiring simultaneous or sequential analysis of multiple electrical and optically sensed signals has been developed. A maximum of six analog signals are input to the processor. A measurement mode selector determines what signals are to be analyzed and the initial timing sequence of sense gates for acquiring signal crest values. Processor signal‐triggering and sense gate time delays are selectable. Logic coincidence‐anticoincidence circuits determine constraints on incoming signals. Gated peak‐sense and hold signals are routed to computer interface electronics for digitizing and are then displayed as frequency distribution histograms using an LSI‐11 computer. Signals also are processed as single parameters, ratios, and gated single parameters for output to a multichannel pulseheight analyzer and cell sorting electronics. The functional features of the processor are described along with examples illustrating simultaneous and sequential analysis of cultured cells stained with fluorescent dyes.
Quantitation of cell concentration using the flow cytometer
Authors: Stewart Carleton C. , Steinkamp John A.
Published: June 2010

A simple procedure has been developed to simultaneously measure cell concentration and analyze marker positive cell populations using the flow cytometer. Fluorescent latex particles of known concentration are added to the sample to be analyzed. Marker positive cells and fluorescent particles are then analyzed using flow cytometric methods. Since the particle concentration is known, the number of particles that have accumulated gives the exact volume of the sample analyzed. The concentration of total and marker positive cells that were analyzed then can be calculated. The method will be illustrated using single, dual, and triple laser excitation of cells stained for DNA content in combination with green or red fluorescent spheres. The usefulness of the procedure is demonstrated by counting cells from highly necrotic tumors where large amounts of debris are present.
Optical diffraction as a tool for semiautomatic, quantitative analysis of tissue specimens
Authors: Różycka M. , Lenczowski S. , Sawicki W. , Barańska W. , Ostrowski K.
Published: June 2010

Optical diffraction was tested on electron micrographs of normal and malformed myelin sheaths as a method for semiautomatic quantitative analysis of tissue specimens. Both normal and malformed myelin sheaths were chosen for the analysis because of their characteristic internal structure and its alteration as a result of malformation. Optical diffraction patterns were obtained by means of an optical diffractometer coupled with a digital detector. The spacing and arrangement of the components of various types of myelin sheath were automatically calculated and determined and the results were verified with discriminant analysis. Out of 27 parameters of the radial and out of 25 parameters of the angular distributions of diffracted light intensity, 6 and 11, respectively, were found to have good discriminative power and were used for classification of myelin sheaths. The accuracy of automatic classification was tested by comparison with myelin sheath types of known origin. The samples visually similar by their appearance, e.g. control and regenerating myelin sheaths, were automatically classified with accuracy of 69%, whereas others were classified appropriately with 88–100% accuracy. It is believed that this kind of analysis may successfully be applied for specimens of other tissues and/or organs.
Applications of flow cytometry on bacteria: Cell cycle kinetics, drug effects, and quantitation of antibody binding
Authors: Steen Harald B. , Boye Erik , Skarstad Kirsten , Bloom Barry , Godal Tore , Mustafa Salim
Published: June 2010

Dual parameter flow cytometric analysis of bacteria has been found technically feasible. A microscope based flow cytometer with either a 100 W Hg‐arc or a 5 W Ar laser as the excitation light source was used to record fluorescence and light scatter simultaneously to produce three dimensional histograms correlating the two parameters. Cells of Escherichia coli K‐12 were fixed in ethanol and stained with mithramycin. Fluorescence (DNA)/light scatter histograms of cells in various phases of growth were recorded at a rate of up to 1 × 104 cells/sec with an instrumental resolution corresponding to coefficient of variation < 5%. Similar histograms of cells stained with FITC indicated that light scatter was approximately proportional to total cell protein. Histograms showing the relative cellular contents of DNA and protein in cultures of rapidly growing E. coli were in quantitative agreement with a current model of bacterial growth. Histograms of E. coli in slow growth indicated that a significant portion of the cells were in a nonreplicating phase. Four antibiotics, all ribosomal inhibitors of protein synthesis, were found to affect the cell cycle differently when present in concentrations sufficient to stop cell division. Mycobacterium leprae bacilli were coated with FITC‐labeled M. leprae specific, human antiserum and with a BCG antiserum. The resulting FITC fluorescence/light scatter histograms yielded the amount of antibody per cell as related to cell size thus facilitating a determination of antigenicity per unit cell weight. The results exemplify bacteriological applications of flow cytometry and demonstrate the efficiency of the method in obtaining detailed and precise information on single bacteria in large numbers.
Flow cytometric analysis of cellular DNA in human acute nonlymphatic leukemias and dysmyelopoietic syndromes
Authors: Maiolo A. T. , Foa P. , Mozzana R. , Chiorboli O. , Ciani A. , Maisto A. , Starace G.
Published: June 2010

The proliferation patterns of bone marrow cells from 16 cases of acute nonlymphatic leukemia (ANLL) and 13 of dysmyelopoietic syndromes were analyzed with DNA‐flow cytometry. In order to reduce the contamination by nonproliferating peripheral blood cells, all aspirates were submitted to a density centrifugation step. DNA content measurements were performed with a PHYWE ICP 22 flow system apparatus. The distribution of cells in the cell cycle phases was calculated by means of an automated fitting procedure.

No significant difference between the cell cycle distribution in ANLL and dysmyelopoietic syndromes was detectable. No relationship was observed between the size of the S phase compartment and the percentage of blasts in the original samples. Aspirates from ANLL were also cultured in vitro in liquid phase on dialysis membranes. A clear relationship was observed between the size of the phase compartment and in vitro cell growth since, with the exception of one case, all samples with less than 11% cells in S phase failed to proliferate in vitro. The proliferation profile of ANLL cells after 10 days in culture was similar to that of the original samples.
Extraction of morphological features from biological models and cells by fourier analysis of static light scatter measurements
Authors: Burger D. E. , Jett J. H. , Mullaney P. F.
Published: June 2010

Models of biological cells of varying geometric complexity were used to generate data to test a method of extracting geometric features from light scatter distributions. Measurements of the dynamic range and angular distribution of intensity and light scatter from these models was compared to the distributions predicted by a complete theory of light scatter (Mie) and by diffraction theory (Fraunhofer). An approximation to the Fraunhofer theory provides a means of obtaining size and shape features from the data by a spectrum analysis. Experimental verification using nucleated erythrocytes as the biological material show the potential application of this method for the extraction of important size and shape parameters from light scatter data.
Multi‐Parameter, computer controlled operation of a FACS II cell sorter
Authors: Peters Donald C. , Dean Phillip N. , Merrill John T.
Published: June 2010

The ease of operation and versatility of a FACS II cell sorter were improved by replacing the original pulse height analyzer (PHA) with a computer‐based dual parameter PHA and a single channel analyzer (SCA). An ND620 LSI‐11 based PHA is now used to generate the sorting decisions. Sorting windows are created by intensifying one or more regions of any shape on the PHA single or dual parameter histograms. For three parameter operation, the third parameter SCA controls the dual parameter information sent to the analyzer. The SCA can also trigger an abort circuit during the PHA 15 microsecond analyzing dead time, improving the purity of the sorted fraction. The electronics that interfaces the new PHA to the sorter replaces all of the original FACS II analog signal processing circuitry with an interchangeable circuit board. The principles involved should apply to any cell sorter.
Data acquisition and control system for multiparameter cell sorting based on DEC LSI‐11 microprocessor
Authors: Voet L. , Kurmann F. J. , Hannig K.
Published: June 2010

A computer system has been developed to add data acquisition, display, storage, and processing capability to a multiparameter flow cytometer/sorter. The system can handle one or two parameters in histogram mode. Alternatively one, two or more parameters are stored event‐by‐event on an external storage device in list‐mode with a resolution of 12 bit. The processor can also control cell sorting. Usual multichannel analyzer features are implemented in software, using standard interface boards without special electronics. Data are accepted via Direct Memory Access (DMA), which depends only on hardware. Data acquisition deadtime is nearly independent of software routines such as graphics display and interactive work. Since more than 8000 events/sec are achieved for eight parameter handling, the computer system has capacity for rapid data acquisition. Although there is no need for such high data acquisition rates in present flow cytometry, it gives the advantage of short single event acquisition and longer process control handling.
Flow cytofluorometric analysis of insulin binding and internalization by swiss 3T3 cells
Authors: Murphy Robert F. , Powers Scott , Verderame Michael , Cantor Charles R. , Pollack Robert
Published: June 2010

The binding of a fluorescein‐isothiocyanate derivative of insulin to Swiss 3T3 cells was measured by flow cytometry. The kinetics of the subsequent internalization were also measured; at a concentration of 1 μM labeled insulin approximately 25% of the internalization was insulin‐specific. The kinetics of endocytosis were contrasted to those of fluorescent derivatives of histone and dextran. In addition, the fusion of endocytic vesicles containing insulin or dextran with lysosomes was detected by measuring the pH‐dependent increase in fluorescein fluorescence caused by the addition of chloroquine. The application of these results to the analysis of growth control by insulin and related hormones is discussed.
Regional white matter development in children with autism spectrum disorders
Authors: Carmody Dennis P. , Lewis Michael
Published: June 2010

In this pilot study the severity of autism spectrum disorders (ASD) was associated with alterations in white matter development. Children with ASD and without ASD were assessed by magnetic resonance imaging (MRI) for their myelination development on a regional basis. Measures were obtained in medial frontal cortex, temporal poles, and temporo‐parietal junction in both left and right hemispheres. Children with ASD showed myelination that was greater than expected for their age in both left and right medial frontal cortex and showed myelination that was less than expected in left temporo‐parietal junction. The severity of ASD symptoms, as assessed by the Autism Diagnostic Observation Schedule—Generic, was associated more with left hemisphere alterations than right hemisphere. © 2010 Wiley Periodicals, Inc. Dev Psychobiol 52: 755–763, 2010.
Anion‐Induced Assembly of Hexacoordinate Rare‐Earth(III) Complexes
Authors: Tanase Stefania , Sottini Silvia , Marvaud Valerie , Groenen Edgar J. J. , Chamoreau Lise‐Marie
Published: June 2010

Rare‐earth(III) complexes of the general formula [RE{(Hsal)3tren}2](CF3SO3)3·nCH3CN, where RE is Eu (1), Gd (2), and Tb (3), and (Hsal)3tren is tris[2‐(salicylideneimino)ethyl]amine, have been synthesized and structurally characterized. X‐ray crystallographic studies show that the rare‐earth(III) center is coordinated by six oxygen atoms that belong to thephenolato groups of two (Hsal)3tren ligand molecules to give an unusual hexacoordinate geometry. The molecular structure is stabilized by strong intramolecular interactions established between the hydrogen atoms located on the three imino nitrogen atoms and the deprotonated phenol oxygen atoms of each ligand. Luminescence studies have indicated the presence of efficient nonradiative deactivation pathways in 1–3, and only a weak ligand emission was observed (λexc = 275 nm, λem = 545 nm) in all cases. Temperature‐dependent magnetic susceptibility studies have shown that crystal field effects are dominant for complex 3, whilst small antiferromagnetic interactions have been observed in 2.
N‐Coordinated [2Fe–2S] and [4Fe–4S] Clusters: Synthesis, Structures and Spectroscopic Characterisation
Authors: Fuchs Michael G. G. , Dechert Sebastian , Demeshko Serhiy , Meyer Franc
Published: June 2010

Examples for [2Fe–2S] clusters with non‐chelating N‐coordinating ligands are still relatively rare, and no mixed‐valent [4Fe–4S] cluster with pure N‐donor ligation has hitherto been reported. In the course of synthetic efforts to isolate a biorelevant [2Fe–2S] cluster 2 with 2‐methylindolato capping ligands, the respective [4Fe–4S] cluster 3 was isolated as a by‐product and characterised by X‐ray diffraction. Since 3 represents the first all‐N‐ligated mixed‐valent [4Fe–4S] complex, rational syntheses for 3 as well as for 2 were then developed. Both complexes are quite unstable in solution, but have been characterised as far as possible by a variety of spectroscopic methods including 1H NMR, UV/Vis and Mößbauer.
Spirocycle (SitBu3)6Si9Cl2: The First of Its Kind among Group 14 Elements
Authors: Klapötke Thomas M , Vasisht Sham Kumar , Mayer Peter
Published: June 2010

Structural studies on (R*3Si4)2SiCl2, prepared by the reaction of tetrasilatetrahedranide KR*3Si4 with SiCl4, show that the tetrahedral moieties R*3Si4 undergo structural transformation. The molecule exhibits a spiro[4.4]nonasilane network that comprises two homonuclear tricyclo[2.1.0.02,5]pentasilane rings with a common “naked” silicon bridge. The compound shows structural similarities with R*6Si8, which consists of similar rings fused together along an Si–Si bridge. Comparison of valence angles, interplanar angles and bridgehead distances with respect to tricyclo[2.1.0.02,5]pentanes or similar ring systems with heteronuclear group homologues are reported to highlight the influence of bulky supersilyl R* groups in the structure.
Paramagnetic (1,3‐Diborolyl)ruthenium Triple‐Decker Complexes and Transformation into Diamagnetic Complexes Having Bridging 1,3‐Diborafulvene Ligands (Eur. J. Inorg. Chem. 19/2010)
Authors: Mutseneck Elena V. , Wadepohl Hubert , Enders Markus , Kudinov Alexander R. , Siebert Walter
Published: June 2010

The cover picture shows the serendipitous transformation of the yellow into the dark orange triple‐decker sandwich complex by air. The unique B=CH2 group formed strongly leans toward one of the metal atoms. Non‐equivalence of the Cp*Ru groups suggests a bridge inversion, which does not occur below 70 °C. At higher temperatures the signals of the Cp* protons broaden, but coalescence is not reached in toluene. Details are discussed in the article by M. Enders, A. R. Kudinov, W. Siebert et al. on p. 2911 ff.
Intra‐ and Intermolecular Oxa‐Pictet–Spengler Cyclization Strategy for the Enantioselective Synthesis of Deoxy Analogues of (+)‐Nanomycin A Methyl Ester, (+)‐Eleutherin, (+)‐Allo‐Eleutherin, and (+)‐Thysanone
Authors: Sawant Rajiv T. , Jadhav Satish G. , Waghmode Suresh B.
Published: June 2010

Enantioselective synthesis of deoxy analogues of pyranonaphthoquinone antibiotics (+)‐nanomycin A methyl ester, (+)‐eleutherin, (+)‐allo‐eleutherin, and (+)‐thysanone was achieved in good overall yield with high enantio‐ and diastereoselectivity from the common intermediate (R)‐3‐(2,5‐dimethoxyphenyl)propane‐1,2‐diol. The intramolecular oxa‐Pictet–Spengler cyclization of 6‐aryl‐1,3‐dioxolone was developed for the first time and utilized in the enantioselective synthesis of (+)‐deoxynanomycin A methyl ester, whereas the intermolecular oxa‐Pictet–Spengler cyclization strategy was applied to the enantioselective synthesis of deoxy analogues of (+)‐eleutherin, (+)‐allo‐eleutherin, and (+)‐thysanone.
MPHT‐Promoted Bromocyclization of ortho‐Substituted Arylalkynes: Application to the Synthesis of 2‐Substituted 3‐Bromobenzofurans and ‐Benzo[b]thiophenes
Authors: Jacubert Maud , Tikad Abdellatif , Provot Olivier , Hamze Abdallah , Brion Jean‐Daniel , Alami Mouâd
Published: June 2010

A convenient and general approach to the synthesis of 2‐substituted 3‐bromobenzofurans and ‐benzothiophenes was developed. The procedure is based on the cyclization of ortho‐substituted arylalkynes in the presence of N‐methylpyrrolidin‐2‐one hydrotribromide (MPHT) as a soft and easy‐to‐handle electrophilic brominating reagent. Under mild reaction conditions, MPHT promoted the bromocyclization of various enynes and diynes as well as arylalkynes to give 2‐substituted 3‐bromobenzofurans and ‐benzothiophenes in high to excellent yields. Subsequent functionalization by palladium‐catalyzed coupling reactions at the C–Br bond afforded general access to 2,3‐disubstituted benzofurans and benzothiophenes of biological interest.
Metal Nanoparticle Modified Boron Doped Diamond Electrodes for Use in Electroanalysis
Authors: Toghill Kathryn E. , Compton Richard G.
Published: June 2010

Metal nanoparticle modified boron‐doped diamond (BDD) electrodes have been used in the electroanalysis of a number of inorganic and organic analytes. This simple surface modification has enhanced the sensitivity and analytical ability of BDD effectively and consistently, as reported in a number of publications overviewed herein. In this review, a number of metal nanoparticle systems that have utilized BDD electrodes will be discussed. The low capacitance of BDD makes it an ideal substrate for sensitive dynamic electroanalytical experiments. The metal nanoparticle modification of BDD offers a simple yet effective approach to enhancing the electroanalytical ability of the electrode material.
Chemometric analysis of urine fingerprints acquired by liquid chromatography‐mass spectrometry and capillary electrophoresis: Application to the schistosomiasis mouse model
Authors: Garcia‐Perez Isabel , Earll Marc E. , Angulo Santiago , Barbas Coral , Legido‐Quigley Cristina
Published: June 2010

Urine fingerprints from Schistosoma mansoni infected and control animals were acquired with ultra performance liquid chromatography‐MS (UPLC‐MS) and compared with the urine fingerprints obtained by CE by applying the same set of multivariate analysis tools. Principal component analysis of the aligned data provided a time trajectory where the infection was observed after 30 days with UPLC‐MS and CE. Two main markers describing infected and control, respectively – phenyl acetyl glycine (PAG) and hippurate – were selected to illustrate the use of orthogonal partial least‐square discriminant analysis in determining the discriminatory confidence. PAG was found to be significantly related to the disease (high covariance and correlation), whereas hippurate was found to be nonsignificant as an indicator. Orthogonal partial least‐square discriminant analysis models were validated for sensitivity and specificity. Multivariate data analysis derived from two different detection systems showed that CE‐UV and UPLC‐MS found equivalent results. This work gives additional mechanistic insight into the progress of the S. mansoni infection; the biochemical role and specificity of PAG as a biomarker is yet to be determined.
Application of champedak mannose‐binding lectin in the glycoproteomic profiling of serum samples unmasks reduced expression of alpha‐2 macroglobulin and complement factor B in patients with nasopharyngeal carcinoma
Authors: Seriramalu Ramarao , Pang Wei Wei , Jayapalan Jaime Jacqueline , Mohamed Emida , Abdul‐Rahman Puteri Shafinaz , Bustam Anita Zarina , Khoo Alan Soo‐Beng , Hashim Onn Haji
Published: June 2010

The use of lectin affinity chromatography prior to 2‐DE separation forms an alternative method to unmask the expression of targeted glycoproteins of lower abundance in serum samples. Reduced expression of α‐2 macroglobulin (AMG) and complement factor B (CFB) was detected in sera of patients with nasopharyngeal carcinoma (NPC) when pooled serum samples of the patients and those of healthy individuals were subjected to affinity isolation using immobilized champedak mannose‐binding lectin and analyzed by 2‐DE and densitometry. The AMG and CFB spots were not detected in the 2‐DE protein profiles when the same pooled serum samples were subjected to albumin and IgG depletion and neither were they detected when the depleted samples were analyzed by western blotting and lectin detection. Together with other acute‐phase response proteins that were previously reported to be altered in expression in NPC patients, AMG and CFB may serve as useful complementary biomarkers for NPC.
On the formation of dissolution pipes in Quaternary coastal calcareous arenites in Mediterranean settings
Authors: De Waele Jo , Lauritzen Stein‐Erik , Parise Mario
Published: June 2010

A large number of uniform cone‐shaped dissolution pipes has been observed and studied in Quaternary coastal calcareous arenites in Apulia and Sardinia (Italy) and Tunisia. These cylindrical tubes have a mean diameter of 52·8 cm and are up to 970 cm deep (mean depth for sediment‐free pipes is 1·38 m). They generally have smooth walls along their length, are perfectly vertical and taper out towards their bottoms. Their development is not influenced by bedding nor fractures. Sometimes their walls are coated by a calcrete crust. Their morphology has been studied in detail and their relationships with the surrounding rocks and with the environment have been analysed. The perfectly vertical development is a clear evidence of their genesis controlled by gravity. The depth of the dissolution pipes can be described by an exponential distribution law (the Milanovic distribution), strongly suggesting they developed by a diffusion mechanism from the surface vertically downward. We believe dissolution pipes preferentially form in a covered karst setting. Local patches of soil and vegetation cause infiltration water to be enriched in carbon dioxide enhancing dissolution of carbonate cement and local small‐scale subsidence. This process causes the formation of a depression cone that guides infiltrating waters towards these spots giving rise to the downward growth of gravity‐controlled dissolution pipes. A change of climate from wetter phases to drier and hotter ones causes the formation of a calcrete lining, fossilizing the pipes. When the pipes become exposed to surface agents by erosion of the sediment cover or are laterally breached the loose quartz sand filling them may be transported elsewhere. Copyright © 2010 John Wiley & Sons, Ltd.
Snub‐nosed monkeys: Multilevel societies across varied environments
Authors: Kirkpatrick R. Craig , Grueter Cyril C.
Published: June 2010

The ecology and behavior of the four species of Rhinopithecus, snub‐nosed monkeys, are rapidly becoming well known. New field studies reveal in depth the striking adaptations of these colobines. Diets range from those typical for tropical colobines to diets dominated by lichens. The monkeys form bands, at times consisting of more than 400 individuals; these bands are based on the one‐male, multi‐female units common in colobines. We review the diet, range use, and social organization of snub‐nosed monkeys, and then explore the power of socioecological theory to explain their multilevel social organization.
A homologous form of human interleukin 16 is implicated in microglia recruitment following nervous system injury in leech Hirudo medicinalis
Authors: Croq Françoise , Vizioli Jacopo , Tuzova Marina , Tahtouh Muriel , Sautiere Pierre‐Eric , Van Camp Christelle , Salzet Michel , Cruikshank William W. , Pestel Joel , Lefebvre Christophe
Published: June 2010

In contrast to mammals, the medicinal leech Hirudo medicinalis can completely repair its central nervous system (CNS) after injury. This invertebrate model offers unique opportunities to study the molecular and cellular basis of the CNS repair processes. When the leech CNS is injured, microglial cells migrate and accumulate at the site of lesion, a phenomenon known to be essential for the usual sprouting of injured axons. In the present study, we demonstrate that a new molecule, designated HmIL‐16, having functional homologies with human interleukin‐16 (IL‐16), has chemotactic activity on leech microglial cells as observed using a gradient of human IL‐16. Preincubation of microglial cells either with an anti‐human IL‐16 antibody or with anti‐HmIL‐16 antibody significantly reduced microglia migration induced by leech‐conditioned medium. Functional homology was demonstrated further by the ability of HmIL‐16 to promote human CD4+ T cell migration which was inhibited by antibody against human IL‐16, an IL‐16 antagonist peptide or soluble CD4. Immunohistochemistry of leech CNS indicates that HmIL‐16 protein present in the neurons is rapidly transported and stored along the axonal processes to promote the recruitment of microglial cells to the injured axons. To our knowledge, this is the first identification of a functional interleukin‐16 homologue in invertebrate CNS. The ability of HmIL‐16 to recruit microglial cells to sites of CNS injury suggests a role for HmIL‐16 in the crosstalk between neurons and microglia in the leech CNS repair. © 2010 Wiley‐Liss, Inc.
Bile formation: Do not ignore the role of plasma membrane-cytoskeleton linking proteins
Authors: Lazaridis Konstantinos N. , LaRusso Nicholas F.
Published: June 2010

The ezrin-radixin-moesin (ERM) family of proteins crosslink ac-tin filaments and integral membrane proteins. Radixin (encoded by Rdx) is the dominant ERM protein in the liver of wildtype mice and is concentrated at bile canalicular membranes (BCMs). Here we show that Rdx(-/-) mice are normal at birth, but their serum concentrations of conjugated bilirubin begin to increase gradually around 4 weeks, and they show mild liver injury after 8 weeks. This phenotype is similar to human conjugated hyperbiliru-binemia in Dubin-Johnson syndrome, which is caused by mutations in the multidrug resistance protein 2 (MRP2, gene symbol ABCC2), although this syndrome is not associated with overt liver injury. In wildtype mice, Mrp2 concentrates at BCMs to secrete conjugated bilirubin into bile. In the BCMs of Rdx / mice, Mrp2 is decreased compared with other BCM proteins such as dipeptidyl peptidase IV (CD26) and P-glycoproteins. In vitro binding studies show that radixin associates directly with the car-boxy-terminal cytoplasmic domain of human MRP2. These findings indicate that radixin is required for secretion of conjugated bilirubin through its support of Mrp2 localization at BCMs.
Anti-selectin therapy against hepatic ischemia-reperfusion injury
Authors: Jaeschke Hartmut
Published: June 2010

Evidence shows that leukocyte recruitment into inflamed liver sinusoids does not require selectins, with one notable exception: ischemia-reperfusion (I/R). We used intravital microscopy to directly visualize the liver microcirculation during I/R and localized endotoxemia (liver superfused with lipopolysaccharide). General anti-selectin therapy (fucoidan) or anti-adhesion therapy with an antithrombin inhibitor (hirudin) was also used. Many neutrophils rolled and adhered in postsinusoidal vessels and sequestered in the sinusoids during I/R and local endotoxin superfusion. Although fucoidan blocked rolling in both forms of inflammation, leukocyte recruitment into sinusoids was only blocked in I/R. Adhesion was also inhibited in postischemic sinusoids with a second anti-adhesive agent (hirudin). Because liver I/R inevitably induces ischemia upstream in the intestine, anti-selectin therapy may prevent intestinal injury, which could prevent downstream liver inflammation. To test this hypothesis, we completely removed the intestine and rerouted blood flow from the superior mesenteric artery to the superior mesenteric vein. I/R was induced in the liver microcirculation, and many leukocytes rolled and adhered in postsinusoidal venules and adhered in sinusoids. Although fucoidan significantly reduced the rolling in postsinusoidal vessels, adhesion persisted in the sinusoids. Our data suggest that anti-adhesion therapy is effective in liver I/R in the sinusoids and postsinusoidal venules, perhaps in part due to its beneficial effect on the intestine.
The Abcs of Biliary Cholesterol Secretion and Their Implication for Gallstone Disease
Authors: Zanlungo Silvana , Miquel Juan Francisco , Rigotti Attilio , Nervi Flavio
Published: June 2010

Two ATP–binding cassette (ABC) transporters, ABCG5 and ABCG8, have been proposed to limit sterol absorption and to promote biliary sterol excretion in humans. To test this hypothesis, a P1 clone containing the human ABCG5 and ABCG8 genes was used to generate transgenic mice. The transgenes were expressed primarily in the liver and small intestine, mirroring the expression pattern of the endogenous genes. Transgene expression only modestly affected plasma and liver cholesterol levels but profoundly altered cholesterol transport. The fractional absorption of dietary cholesterol was reduced by about 50%, and biliary cholesterol levels were increased more than fivefold. Fecal neutral sterol excretion was increased three– to six–fold and hepatic cholesterol synthesis increased two– to four–fold in the transgenic mice. No significant changes in the pool size, composition, and fecal excretion of bile acids were observed in the transgenic mice. Transgene expression attenuated the increase in hepatic cholesterol content induced by consumption of a high cholesterol diet. These results demonstrate that increased expression of ABCG5 and ABCG8 selectively drives biliary neutral sterol secretion and reduces intestinal cholesterol absorption, leading to a selective increase in neutral sterol excretion and a compensatory increase in cholesterol synthesis.
Of Chimps and Men-Finding the Path to An Hcv Vaccine
Authors: Diepolder Helmut M. , Gruener Norbert H. , Heeney Jonathan
Published: June 2010

To define the early events that determine the outcome of acute hepatitis C virus (HCV) infection, we compared the course of viremia with the peripheral and intrahepatic T cell response and intrahepatic cytokine profile in six acutely infected chimpanzees. Three different outcomes were observed after peak viral titers were reached: sustained viral clearance, transient viral clearance followed by chronic infection, and chronic infection that persisted at initial peak titers. The results indicate that HCV spread outpaces the T cell response and that HCV rapidly induces but is not controlled by IFN–α/β; that viral clearance follows the entry and accumulation of HCV–specific IFN–gamma–producing T cells in the liver; and that it may not require the destruction of infected cells.
Ask(1) and You Shall Receive: A New Link Between Antioxidants and Cell Death Signaling
Authors: Czaja Mark J.
Published: June 2010

Hepatoprotection mediated by free radical scavenging molecules such as dimethyl sulfoxide (Me2SO) arose the question as to whether this effect involved one or several anti–apoptotic signals. Here, using primary cultures of rat hepatocytes and in vivo thioacetamide–induced liver failure, we showed that Me2SO failed to prevent any cleavage of initiator caspase–8 and –9 but constantly inhibited procaspase–3 maturation and apoptosis execution, pointing to an efficient inhibition of cleaved initiator caspase activities. Evidence was recently provided that apoptosis might require both caspase and ASK1/JNK–p38 activities. We demonstrated that this kinase pathway was strongly inhibited in the presence of Me2SO whereas overexpression of ASK1 was able to restore caspase–3 activity and apoptosis. Interestingly, we also found that GST M1/2 and GST A1/2 dropped under apoptotic conditions; furthermore transfection of GST M1, A1, or P1 to cells overexpressing ASK1, abolished caspase–3 activity and restored viability. This role of GSTs was further assessed by showing that their high expression level was tightly associated with inhibition of ASK1 activity in Me2SO–protected hepatocytes. Together, these results demonstrate that Me2SO–mediated hepatoprotection involves a dual inhibition of cleaved initiator caspase and ASK1/JNK–p38 activities. Furthermore, in highlighting the control of apoptosis by GSTs, these data provide new insights for analyzing the complex mechanisms of hepatoprotection.
Evasive Maneuvers by Hepatitits C Virus
Authors: Lindenbach Brett D. , Rice Charles M.
Published: June 2010

The hepatitis C virus (HCV) serine protease is necessary for viral replication and represents a valid target for developing new therapies for HCV infection. Potent and selective inhibitors of this enzyme have been identified and shown to inhibit HCV replication in tissue culture. The optimization of these inhibitors for clinical development would greatly benefit from in vitro systems for the identification and the study of resistant variants. We report the use of HCV subgenomic replicons to isolate and characterize mutants resistant to a protease inhibitor. Taking advantage of the replicons' ability to transduce resistance to neomycin, we selected replicons with decreased sensitivity to the inhibitor by culturing the host cells in the presence of the inhibitor and neomycin. The selected replicons replicated to the same extent as those in parental cells. Sequence analysis followed by transfection of replicons containing isolated mutations revealed that resistance was mediated by amino acid substitutions in the protease. These results were confirmed by in vitro experiments with mutant enzymes and by modeling the inhibitor in the three–dimensional structure of the protease.
Activity‐dependent intracellular chloride accumulation and diffusion controls GABAA receptor‐mediated synaptic transmission
Authors: Jedlicka Peter , Deller Thomas , Gutkin Boris S. , Backus Kurt H.
Published: June 2010

In the CNS, prolonged activation of GABAA receptors (GABAARs) has been shown to evoke biphasic postsynaptic responses, consisting of an initial hyperpolarization followed by a depolarization. A potential mechanism underlying the depolarization is an acute chloride (Cl−) accumulation resulting in a shift of the GABAA reversal potential (EGABA). The amount of GABA‐evoked Cl− accumulation and accompanying depolarization depends on presynaptic and postsynaptic properties of GABAergic transmission, as well as on cellular morphology and regulation of Cl− intracellular concentration ([Cl−]i). To analyze the influence of these factors on the Cl− and voltage behavior, we studied spatiotemporal dynamics of activity‐dependent [Cl−]i changes in multicompartmental models of hippocampal cells based on realistic morphological data. Simulated Cl− influx through GABAARs was able to exceed physiological Cl− extrusion rates thereby evoking HCO3− ‐dependent EGABA shift and depolarizing responses. Depolarizations were observed in spite of GABAA receptor desensitization. The amplitude of the depolarization was frequency‐dependent and determined by intracellular Cl− accumulation. Changes in the dendritic diameter and in the speed of GABA clearance in the synaptic cleft were significant sources of depolarization variability. In morphologically reconstructed granule cells subjected to an intense GABAergic background activity, dendritic inhibition was more affected by accumulation of intracellular Cl− than somatic inhibition. Interestingly, EGABA changes induced by activation of a single dendritic synapse propagated beyond the site of Cl− influx and affected neighboring synapses. The simulations suggest that EGABA may differ even along a single dendrite supporting the idea that it is necessary to assign EGABA to a given GABAergic input and not to a given neuron. © 2010 Wiley‐Liss, Inc.
An investigation of preschoolers' misattributions of the properties of two‐dimensional images: understanding the relationship between a symbol and its referent
Authors: Claxton Laura J.
Published: June 2010

Previous studies have found that preschoolers are confused about the relationship between two‐dimensional (2D) symbols and their referents. Preschoolers report that 2D images (e.g. televised images and photographs) share some of the characteristics of the objects they are representing. A novel Comparison Task was created to test what might account for these misattributions of the properties of 2D images. Three‐and‐a‐half‐ and four‐and‐a‐half‐year olds made comparisons between items presented in two of three formats simultaneously, i.e. as a real object and as an object appearing on television (TV), as a real object and as a photo of that object, or as an object appearing on TV and in a photo. Presenting the televised object or the photo of the object along with the real object aided performance; children indicated that televised objects and photos of objects no longer shared the properties of the real objects. Children also performed better when presented with two 2D images of the same object (the photo of the object and the televised image of the object). Although dual‐representation might account for these misattributions of the properties of 2D images, because children also performed better when two 2D images of the same object were present, other possibilities such as children using pictures as communicative devices and disregarding the pragmatics of the task should be explored. Copyright © 2010 John Wiley & Sons, Ltd.
DNA damage in brain cells and behavioral deficits in mice after treatment with high doses of amantadine
Authors: Kaefer Vanessa , Semedo Juliane Garcia , Silva Kahl Vivian Francília , Von Borowsky Rafael Gomes , Gianesini Janaína , Ledur Kist Tarso Benigno , Pereira Patrícia , Picada Jaqueline Nascimento
Published: June 2010

Amantadine (AMA) is an uncompetitive antagonist of theN‐methyl‐d‐aspartate receptor, with clinical application, acting on treatment of influenza A virus and Parkinson's disease. It has been proposed that AMA can indirectly modulate dopaminergic transmission. In high doses, the central nervous system is its primary site of toxicity. To examine deleterious effects on CNS induced by AMA, this study evaluated possible neurobehavioral alterations induced by AMA such as stereotyped behavior, the effects on locomotion and memory and its possible genotoxic/mutagenic activities. Adult male CF‐1 mice were treated with a systemic injection of AMA (15, 30 or 60 mg kg−1) 20 min before behavioral tasks on open field and inhibitory avoidance. Higher AMA doses increased the latency to step‐down inhibitory avoidance test in the training session in the inhibitory avoidance task. At 60 mg kg−1AMA induced impairing effects on locomotion and exploration and hence impaired habituation to a novel environment. Stereotyped behavior after each administration in a 3‐day trial was observed, suggesting effects on dopaminergic system. Amantadine was not able to induce chromosomal mutagenesis or toxicity on bone marrow, as evaluated by the micronucleus assay. At the lowest dose tested, AMA did not induce DNA damage and it was unable to impair memory, locomotion, exploration or motivation in mice. However, higher AMA doses increased DNA damage in brain tissue, produced locomotor disturbances severe enough to preclude testing for learning and memory effects, and induced stereotypy, suggesting neurotoxicity.