bluuebunny/crossref_metadata_2025 huggingface dataset:
Nuclear estrogen receptor targeted photodynamic therapy: Selective uptake and killing of MCF‐7 breast cancer cells by a C17α‐alkynylestradiol‐porphyrin conjugate
Authors: Swamy Narasimha , Purohit Ajay , Fernandez‐Gacio Ana , Jones Graham B. , Ray Rahul
Published: June 2006

We hypothesized that over‐expression of estrogen receptor (ER) in hormone‐sensitive breast cancer could be harnessed synergistically with the tumor‐migrating effect of porphyrins to selectively deliver estrogen‐porphyrin conjugates into breast tumor cells, and preferentially kill the tumor cells upon exposure to red light. In the present work we synthesized four (4) conjugates of C17‐α‐alkynylestradiol and chlorin e6‐dimethyl ester with varying tether lengths, and showed that all these conjugates specifically bound to recombinant ERα. In a cellular uptake assay with ER‐positive MCF‐7 and ER‐negative MDA‐MB 231 human breast cancer cell‐lines, we observed that one such conjugate (E17‐POR, XIV) was selectively taken up in a dose‐dependent and saturable manner by MCF‐7 cells, but not by MDA‐MB 231 cells. Furthermore, MCF‐7 cells, but not MDA‐MB 231 cells, were selectively and efficiently killed by exposure to red light after incubation with E17‐POR. Therefore, the combination approach, including drug‐ and process modalities has the potential to be applied clinically for hormone‐sensitive cancers in organs where ER is significantly expressed. This could potentially be carried out either as monotherapy involving a photo‐induced selective destruction of tumor cells and/or adjuvant therapy in post‐surgical treatment for the destruction of residual cancer cells in tissues surrounding the tumor. J. Cell. Biochem. 99: 966–977, 2006. © 2006 Wiley‐Liss, Inc.
Phenol red reduces ROSC mediated cell cycle arrest and apoptosis in human MCF‐7 cells
Authors: Węsierska‐Gądek Józefa , Schreiner Tanja , Gueorguieva Marieta , Ranftler Carmen
Published: June 2006

We reported recently that roscovitine (ROSC), a selective cyclin‐dependent kinase (CDK) inhibitor, arrested human MCF‐7 breast cancer cells in G2phase of the cell cycle and concomitantly induced apoptosis. On the other hand, ROSC‐induced G1arrest observed by another group has not been accompanied by apoptosis. Therefore, we decided to prove to which extent components of tissue culture media could affect the primary action of ROSC. For this purpose we compared the efficacy of the ROSC treatment on MCF‐7 cells cultivated in medium with and without phenol red. The kinetics of MCF‐7 cell proliferation strongly depended on the presence of phenol red that has been recognized previously as a weak estrogen. Exposure of MCF‐7 cells cultivated in phenol red‐deprived medium to ROSC resulted in a strong G2arrest and apoptosis. However, the anti‐proliferative and pro‐apoptotic action of ROSC was strongly diminished in cells maintained in medium containing phenol red. The ratio of the G2cell population after 12 h ROSC was reduced by approximately 20% in the latter and correlated with the lack of CDK2 inactivation. Moreover, the kinetics of ROSC‐induced apoptosis was delayed in the presence of phenol red. These results clearly evidence that the efficacy of the therapy of ER‐positive breast cancers by CDK inhibitors is diminished in the presence of estrogen‐mimicking compounds and indicate that phytoestrogens and xenoestrogens could interfere with the therapy. Therefore, the exposure of cancer patients to the estrogen mimics should be avoided at least during chemotherapy by CDK inhibitors. J. Cell. Biochem. © 2006 Wiley‐Liss, Inc.
Identification of murine cdk10: Association with Ets2 transcription factor and effects on the cell cycle
Authors: Bagella Luigi , Giacinti Cristina , Simone Cristiano , Giordano Antonio
Published: June 2006

Cyclin‐dependent kinases (cdks) are the catalytic subunits of a large family of serine/threonine protein kinases whose best‐characterized members are key regulators of eukaryotic cell cycle progression. They are activated by binding to regulatory subunits generally termed as cyclins. Cdk10 is a cdc2‐related kinase that contains the canonical regulatory Tyr and Thr residues present in all protein kinases and a PSTAIRE‐like motif named PISSLRE. Although little is known about this protein, human cdk10 has been shown to encode two different isoforms, each having a distinct function. They differ at both the carboxy‐ and amino‐terminals, although most of the amino acid sequence is predicted to be identical for the two isoforms. A role at the G2/M transition has been suggested for an isoform of cdk10, while the alternative splicing form interacts with the N‐terminus of the Ets2 transcription factor. Here we report the cloning and the functional characterization of a cDNA encoding the murine homologue of cdk10. Unlike its human counterpart, only one murine cdk10 protein has been identified, and this unique murine cdk10 cDNA encodes a putative protein of 360 amino acids. Comparison of the amino acid sequences of murine and human cdk10 shows high homology. Murine cdk10 binds Ets2 transcription factors in vitro, does not show a direct involvement in the G2/M transition and, therefore, does not affect the proliferation rate of the cell lines analyzed. J. Cell. Biochem. 99: 978–985, 2006. © 2006 Wiley‐Liss, Inc.
Inhibition of Notch signaling induces myotube hypertrophy by recruiting a subpopulation of reserve cells
Authors: Kitzmann Magali , Bonnieu Anne , Duret Cédric , Vernus Barbara , Barro Marietta , Laoudj‐Chenivesse Dalila , Verdi Joseph M. , Carnac Gilles
Published: June 2006

During muscle differentiation, a population of quiescent undifferentiated myoblasts (reserve cells) emerges among mature muscle cells. However, the molecular mechanisms underlying such cell segregation and the characterization of this subpopulation of myoblasts remain to be determined. Notch is known to control the behavior and fate of murine muscle stem cells. In this study, we examined the role of Notch in myoblast segregation. We showed that inhibition of Notch activity by either overexpressing Numb or by using a pharmacological γ‐secretase inhibitor (DAPT) enhanced differentiation of murine and human myoblasts. This effect was not restricted to in vitro culture systems since DAPT‐treated zebrafish embryos also showed increased differentiation. Using C2.7 myoblasts as a model, we showed that inhibition of Notch induced myotube hypertrophy by recruiting reserve cells that do not normally fuse. We further showed that endogenous Notch‐signaling components were differentially expressed and activated in reserve cells with respect to Notch 1 and CD34 expression. We identified CD34 negative reserve cells as the subpopulation of myoblasts recruited to fuse into myotubes during differentiation in response to Notch inhibition. Therefore, we showed here that the activation of Notch 1 is important to maintain a subpopulation of CD34 negative reserve cells in an undifferentiated state. J. Cell. Physiol. 208: 538–548, 2006. © 2006 Wiley‐Liss, Inc.
Prostate derived factor in human prostate cancer cells: Gene induction by vitamin D via a p53‐dependent mechanism and inhibition of prostate cancer cell growth
Authors: Lambert James R. , Kelly Julie A. , Shim Minsub , Huffer William E. , Nordeen Steven K. , Baek Seung Joon , Eling Thomas E. , Lucia M. Scott
Published: June 2006

The secosteroid hormone 1α, 25‐dihydroxyvitamin D3(1,25D) has been shown to regulate the growth and differentiation of human prostate cancer (PCa) cells, although the precise molecular mechanisms mediating these effects have not been defined. Previous studies in our laboratory demonstrated that the antiproliferative effects of 1,25D on PCa cells are mediated through the nuclear vitamin D receptor (VDR). In the present study, we performed gene profiling of LNCaP human PCa cells following 1,25D treatment and identified the antitumorigenic gene, prostate derived factor (PDF), as being highly induced by 1,25D. PDF is a member of the TGF‐β superfamily and has been implicated in a variety of functions directly related to tumorigenicity including antiproliferative and pro‐apoptotic effects. Gene expression studies using 1,25D analogs and a VDR antagonist demonstrate that 1,25D‐mediated induction of PDF message and protein in PCa cells is dependent on VDR action. PDF is a transcriptional target of the tumor suppressor, p53. Here we show that the expression of PDF in nine PCa cell lines is dependent on functional p53. Additionally, transfection of p53‐null ALVA‐31 PCa cells with a p53 expression plasmid, and expression of dominant negative p53 in LNCaP PCa cells, show that the ability of VDR to induce PDF requires functional p53. Importantly, forced PDF expression in PC‐3 cells results in decreased cell proliferation, soft agar cloning, and xenograft tumor size. These data demonstrate that PDF exerts antitumorigenic properties on PCa cells and its regulation by 1,25D may provide insights into the action of 1,25D in PCa. J. Cell. Physiol. 208: 566–574, 2006. © 2006 Wiley‐Liss, Inc.
Neurobiology of pain
Authors: Pace M.C. , Mazzariello L. , Passavanti M.B. , Sansone P. , Barbarisi M. , Aurilio C.
Published: June 2006

The neurobiology of pain had a notable interest in research focused on the study of neuronal plasticity development, nociceptors, molecular identity, signaling mechanism, ionic channels involved in the generation, modulation and propagation of action potential in all type of excitable cells. All the findings open the possibility for developing new therapeutic treatment. Nociceptive/inflammatory pain and neuropathic pain represent two different kinds of persistent chronic pain. We have reviewed the different mechanism suggested for the maintenance of pain, like descending nociceptive mechanism and their changes after tissue damage, including suppression and facilitation of defence behavior during pain. The role of these changes in inducing NMDA and AMPA receptors gene expression, after prolonged inflammation is emphasized by several authors. Furthermore, a relation between a persistent pain and amygdale has been shown. Molecular biology is the new frontier in the study of neurobiology of pain. Since the entire genome has been studied, we will able to find new genes involved in specific condition such as pain, because an altered gene expression can regulate neuronal activity after inflammation or tissue damage. J. Cell. Physiol. 209: 8–12, 2006. © 2006 Wiley‐Liss, Inc.
The Cbl family proteins: Ring leaders in regulation of cell signaling
Authors: Swaminathan Gayathri , Tsygankov Alexander Y.
Published: June 2006

The proto‐oncogenic protein c‐Cbl was discovered as the cellular form of v‐Cbl, a retroviral transforming protein. This was followed over the years by important discoveries, which identified c‐Cbl and other Cbl‐family proteins as key players in several signaling pathways. c‐Cbl has donned the role of a multivalent adaptor protein, capable of interacting with a plethora of proteins, and has been shown to positively influence certain biological processes. The identity of c‐Cbl as an E3 ubiquitin ligase unveiled the existence of an important negative regulatory pathway involved in maintaining homeostasis in protein tyrosine kinase (PTK) signaling. Recent years have also seen the emergence of novel regulators of Cbl, which have provided further insights into the complexity of Cbl‐influenced pathways. This review will endeavor to provide a summary of current studies focused on the effects of Cbl proteins on various biological processes and the mechanism of these effects. The major sections of the review are as follows: Structure and genomic organization of Cbl proteins; Phosphorylation of Cbl; Interactions of Cbl; Localization of Cbl; Mechanism of effects of Cbl: (a) Ubiquitylation‐dependent events: This section elucidates the mechanism of Cbl‐mediated downregulation of EGFR and details the PTK and non‐PTKs targeted by Cbl. In addition, it addresses the functional requirements for E3 Ubiquitin ligase activity of Cbl and negative regulation of Cbl‐mediated downregulation of PTKs, (b) Adaptor functions: This section discusses the mechanisms of adaptor functions of Cbl in mitogen‐activated protein kinase (MAPK) activation, insulin signaling, regulation of Ras‐related protein 1 (Rap1), PI‐3′ kinase signaling, and regulation of Rho‐family GTPases and cytoskeleton; Biological functions: This section gives an account of the diverse biological functions of Cbl and includes the role of Cbl in transformation, T‐cell signaling and thymus development, B‐cell signaling, mast‐cell degranulation, macrophage functions, bone development, neurite growth, platelet activation, muscle degeneration, and bacterial invasion; Conclusions and perspectives. J. Cell. Physiol. 209: 21–43, 2006. © 2006 Wiley‐Liss, Inc.
Dependence of GnRH‐induced phosphorylation of CREB and BAD on EGF receptor transactivation in GT1‐7 neuronal cells
Authors: Neithardt Adrienne , Farshori M. Parvaiz , Shah Farzana B. , Catt Kevin J. , Shah Bukhtiar H.
Published: June 2006

The hypothalamic neuropeptide, gonadotropin releasing hormone (GnRH), is a primary regulatory factor in the neuroendocrine control of reproduction. The GnRH decapeptide is released in an episodic manner from hypothalamic GnRH neurons, which are known to express GnRH receptors. Here we examined the signaling pathways by which autocrine GnRH stimulation generates cell survival and proliferative signals in hypothalamic GT1‐7 cells. Both GnRH and epidermal growth factor (EGF) caused rapid phosphorylation of cyclic AMP response element binding protein (CREB) and BAD. The selective epidermal growth factor receptor (EGF‐R) antagonist, AG1478, attenuates the phosphorylation of these proteins by GnRH and EGF. Inhibition of PKC and Src abolished the stimulatory effects of GnRH, but not that of EGF, consistent with a critical role of these signaling molecules upstream of the EGF‐R. All of these effects of GnRH were mimicked by phorbol 12 myristate 13‐acetate (PMA). Consistent with the prosurvival and mitogenic effects of phosphoinositide 3‐kinase/Akt (PI3‐K/Akt) downstream of the EGF‐R, inhibition of PI3‐K diminished the activation of these proteins following stimulation with GnRH, EGF, and PMA. Overexpression of dominant negative Akt attenuated agonist‐induced phosphorylation of BAD, but not that of ERK1/2 and CREB. Moreover, overexpression of wild‐type RSK‐1 resulted in enhanced basal as well as agonist‐induced phosphorylation of CREB and BAD, indicating a critical role of RSK‐1 in activating cytosolic as well as nuclear proteins. These data reveal novel signaling mechanisms of GnRH‐induced phosphorylation of CREB and BAD in GT1‐7 neurons through transactivation of the EGF‐R. J. Cell. Physiol. 208: 586–593, 2006. Published 2006 Wiley‐Liss, Inc.
Focused ion beams techniques for nanomaterials characterization
Authors: Langford Richard M.
Published: June 2006

Focused ion beam and dual platform systems have, over the last 10 years, become a main stay of sample preparation for material analysis. In this article the merits of using these systems are discussed and the three main techniques used to prepare cross‐section specimens for transmission electron microscopy (TEM) are both discussed and compared with emphasis being placed on the tricks that users do to make the lamellae as thin as possible and with a minimum of damage at their sidewalls. Other techniques such as serial slicing for three‐dimensional reconstruction and the preparation of plan‐view specimens are also summarized. Microsc. Res. Tech., 2006. © 2006 Wiley‐Liss, Inc.
Effects of Poly(ethylene glycol), Inorganic Salt, Sodium Dodecyl Sulfate, and Solvent System on Electrospinning of Poly(ethylene oxide)
Authors: Arayanarakul Kunawan , Choktaweesap Nuanchan , Aht‐ong Duangdao , Meechaisue Chidchanok , Supaphol Pitt
Published: June 2006

Summary: The effects of PEO concentration, addition of PEG of various molecular weights (1 000–35 000 g · mol−1), inorganic salt of various types (i.e., NaCl, LiCl, KCl, MgCl2, and CaCl2), or SDS, and the solvent system (i.e., mixed solvents of distilled water and methanol, ethanol, or 2‐propanol) on the bead formation and/or morphological appearance of electrospun PEO fibers were investigated using SEM. The formation of beaded fibers upon addition of low‐molecular‐weight PEGs into the PEO solution suggested that the very short relaxation time and/or the plasticizing effect of these low‐molecular‐weight PEGs contributed to the formation of the bead‐on‐string morphology of the as‐spun fibers. On the other hand, the observed improvement in the electro‐spinnability of the PEO solution with increasing PEO concentration and upon addition of NaCl and SDS suggested that the observed increase in the viscosity and conductivity and the observed decrease in the surface tension of the solution were indispensable for total suppression of the beads. However, when the conductivity of the solution increased only marginally, beads could still be obtained.

SEM image of as‐spun PEO fibers from a solution of PEO in distilled water at 5% w/v without (left) and with (right) 5% w/v PEG of 2 000 g · mol−1.

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SEM image of as‐spun PEO fibers from a solution of PEO in distilled water at 5% w/v without (left) and with (right) 5% w/v PEG of 2 000 g · mol−1.
One‐Pot Synthesis of Novel Poly(cyclotriphosphazene‐co‐sulfonyldiphenol) Microtubes without External Templates
Authors: Zhu Lu , Huang Xiaobin , Tang Xiaozheng
Published: June 2006

Summary: Novel poly(cyclotriphosphazene‐co‐sulfonyldiphenol) microtubes were successfully prepared via one‐pot synthesis using special templates generated in situ during the polymerization. The templates could be easily removed by dissolution in water. This approach overcame the multi‐step nature of general template methods. The as‐synthesized microtubes were 1–3 µm in width, about 100 µm in length and contained hexagon‐shaped channels. IR and NMR spectroscopies confirmed the covalently crosslinked chemical structure of the polymer tubes, and the tubes are thus mechanically and thermally stable. The polymer microtubes are of interest for use as chemical or biological sensors, controlled release and delivery of drugs, tissue engineering materials, absorbants and many other microscale investigations.

SEM images of triethylamine hydrochloride crystals produced in situ during formation of the tubes (left) and the polymer microtubes (right).

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SEM images of triethylamine hydrochloride crystals produced in situ during formation of the tubes (left) and the polymer microtubes (right).
Electron Transfer Photoinitiating Systems. The Effect of the Co‐Initiator Structure on the Photoinitiation Ability of a Photoredox Pair Containing Neutral Hemicyanine Dyes as Sensitizers
Authors: Kabatc Janina , Jędrzejewska Beata , Pączkowski Jerzy
Published: June 2006

Summary: The photoinitiation ability of photoredox pairs composed of a neutral hemicyanine dye and different co‐initiators for the free radical polymerization of 2‐ethyl‐2‐(hydroxymethyl)propane‐1,3‐diol triacrylate is investigated. p‐(N,N‐dimethylaminostyryl)benzthiazole, p‐(N,N‐dimethylaminostyryl)benzoxazole, p‐(N,N‐dimethylaminostyryl)α‐naphthiazole are tested as dyes, and, as co‐initiators, an aromatic amino‐acid, an aromatic thio‐ and oxycarboxylic acid, and alkyltriphenylborate are applied as electron donors. N,N′‐dialkoxybipyridinium salts are used as ground‐state electron acceptors. The experimental results show that the photoinitiating ability of the tested photoredox pairs are controlled by both the driving force of the electron transfer process between an electron donor and an electron acceptor and the reactivity of the free radical that results from the secondary reactions occurring after the photoinduced electron transfer process. The greatest photoinitiation ability of free radical polymerization is observed when the tested dyes are applied as electron donors in their singlet excited states in combination with N,N′‐dialkoxybipyridinium salts acting as ground‐state electron acceptors.

Schematic of the investigated photoinitiation systems.

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Schematic of the investigated photoinitiation systems.
Spontaneously reported fatal suspected adverse drug reactions: a 10‐year survey from Sweden
Authors: Wester Karin , Jönsson Anna , Spigset Olav , Hägg Staffan
Published: June 2006

Purpose

One of the main methods for monitoring the safety of marketed drugs is spontaneously reporting of suspected adverse drug reactions (ADRs). The objective of this study was to describe the pattern of spontaneously reported fatal adverse drug reactions (FADRs) by analysing data from the national spontaneous reporting system in Sweden.

Methods

In Sweden it is compulsory to report all new or serious suspected ADRs to the Medical Products Agency. The information in these reports is stored in the national database SWEDIS (Swedish Drug Information System). All suspected FADRs reported to SWEDIS between 1 January 1995 and 31 December 2004 were reviewed and analysed.

Results

During the study period 990 reports of FADRs were found. The main distribution of suspected FADRs was: haemorrhages (n = 603; 60.9%), blood and bone marrow dysfunction (n = 71; 7.2%), sudden death (n = 38; 3.8%) and pulmonary embolism (n = 30; 3.0%). Antithrombotic agents were the drugs most frequently implicated in the FADRs (n = 605; 61.1%). Vitamin K antagonists were reported in 453 cases (45.8%) and acetylsalicylic acid in 82 cases (8.3%). Among the fatalities with blood and bone marrow dysfunction methotrexate was the most frequently reported drug. For sudden death and pulmonary embolism, antipsychotics and oestrogen containing drugs, respectively, were most commonly reported.

Conclusions

Bleeding complications amounted more than half of all reports of FADRs and vitamin K antagonists were implicated in most of these reports. However, as spontaneous reporting systems are primarily set up for signalling purposes, the data must be interpreted with utmost care. Copyright © 2006 John Wiley & Sons, Ltd.
Erosion‐dependant continuity development in high viscosity ratio blends of very low interfacial tension
Authors: Bhadane Prashant A. , Champagne Michel F. , Huneault Michel A. , Tofan Florin , Favis Basil D.
Published: June 2006

This work studies continuity development and cocontinuity in high viscosity ratio EPDM/PP blends. A very low interfacial tension (0.3 mN/m) between the blend components together with high viscosity ratios (11 and 17) result in a variety of unusual morphological features, including isolated nanometer diameter fibers, very large particles, partially coalesced particles, and numerous particles interconnected by fibers. This unique combination of morphologies leads the blend to a novel and stable cocontinuous structure of partially coalesced particles and particles interconnected by fibers. Compared with low to medium viscosity ratio EPDM/PP blends, these cocontinuous networks demonstrate early percolation thresholds, rapid continuity development, and attain cocontinuity at lower compositions of minor phase. The slow surface erosion of the high viscosity EPDM phase during melt blending is shown to be responsible for the generation of these unusual morphological structures. Typically the timescale for erosion phenomena are so small that they have defied study in the mixing environment itself and typical blend morphology studies almost always examine the final steady‐state morphology obtained after several minutes of mixing. The combination of very low interfacial tension and very high viscosity ratios of these EPDM/PP systems provide a unique opportunity to examine erosion phenomena persisting over longer time scales during melt mixing. We propose a new concentration‐dependant erosion mechanism that is based on particle collision–coalescence–separation dynamics. The proposed conceptual mechanism is shown to dramatically accelerate the erosion process and maintain cocontinuity over prolonged periods of mixing. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 1919–1929, 2006
Molecular dynamics study of onset of water gelation around the collagen triple helix
Authors: Handgraaf Jan‐Willem , Zerbetto Francesco
Published: June 2006

The onset of water gelation around a collagen‐like triple helix peptide was studied at ambient temperature and pressure by performing Molecular Dynamics simulations. The radial distribution functions of the oxygen and hydrogen atoms of water are distorted below 4 Å from the peptide. The distortion is accompanied by the breakdown of the tetrahedral coordination of the hydrogen‐bonded network of water molecules. The water shell around the peptide consists of alternating regions of higher and lower density. In agreement with experiments we find that the first hydration shell is kinetically labile, with a residence time in the order of picoseconds for a water molecule. From the computed diffusion coefficient, a key measure of the collective dynamics, we estimate the average diffusion speed decreases by a factor of 1.5 close to the peptide compared to the liquid. Our results give new insight in gel formation and structure on a molecular level. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Substrate specificity in HIV‐1 protease by a biased sequence search method
Authors: Ozer Nevra , Haliloglu Turkan , Schiffer Celia A.
Published: June 2006

Drug resistance in HIV‐1 protease can also occasionally confer a change in the substrate specificity. Through the use of computational techniques, a relationship can be determined between the substrate sequence and three‐dimensional structure of HIV‐1 protease, and be utilized to predict substrate specificity. In this study, we introduce a biased sequence search threading (BSST) methodology to analyze the preferences of substrate positions and correlations between them that might also identify which positions within known substrates can likely tolerate sequence variability and which cannot. The potential sequence space was efficiently explored using a low‐resolution knowledge‐based scoring function. The low‐energy substrate sequences generated by the biased search are correlated with the natural substrates. Octameric sequences were predicted using the probabilities of residue positions in the sequences generated by BSST in three ways: considering each position in the substrate independently, considering pairwise interdependency, and considering triplewise interdependency. The prediction of octameric sequences using the triplewise conditional probabilities produces the most accurate results, reproducing most of the sequences for five of the nine natural substrates and implying that there is a complex interdependence between the different substrate residue positions. This likely reflects that HIV‐1 protease recognizes the overall shape of the substrate more than its specific sequence. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Electron gyration modified in the magnetic field tilted to the symmetry species of a crystalline metal
Authors: Olszewski S. , Roliński T.
Published: June 2006

When a crystal electron is gyrating in the magnetic field being normal to the crystallographic plane, the calculation of the gyration frequency represents a relatively easy task. The paper approaches a more complicated problem of the gyration frequency in the case when the magnetic field is tilted to the crystallographic axes. The tightly‐bound s‐electrons in crystal lattices of cubic symmetry are considered as examples. Another problem concerns a metal plate for which the changes of the electron gyration frequency are examined as a function of the inclination angle of the magnetic field with respect to the planar boundaries of that plate. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Green's function and excitation spectrum of finite lattices
Authors: Cojocaru S. , Bârsan V. , Ceulemans A.
Published: June 2006

New analytical results are obtained for the Green's function of a finite one‐dimensional lattice with nearest neighbor interaction using discrete Fourier transform. The method offers an alternative to the Bethe Ansatz, but does not require any a priori assumption on the form of the wavefunction. This makes it suitable for extensions to nano‐ferromagnets of higher dimensions. Solutions of the Heisenberg spin chain with periodic and open boundary conditions are considered as examples. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Magnetoabsorption coefficient of donor impurities in CdS quantum dot
Authors: Didi Seddik A. , Zorkani I. , Mdaa A. , Maaza M.
Published: June 2006

A theoretical study of the donor‐related absorption coefficient in spherical CdS quantum dots (QD) in the presence of a uniform magnetic field is performed. The wave functions and the eigenvalues of the initial and final states are obtained in the effective‐mass approximation by using a variational method and a perturbation method, respectively. The results obtained show that the absorption coefficient presents essentially two peaks; one associated with on‐center donors and another related to transitions involving donors at the QD edge. The dependences of the absorption coefficient on sample dimensions, the magnetic field strength and the light polarization are discussed. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Alternative graphical representation of determinantal many‐electron states
Authors: Rettrup Sten
Published: June 2006

The present approach is a graphical procedure for visualizing and addressing determinants and α and β strings for many‐electron systems. Compared with previous approaches, the emphasis in the graph is on the vertices and vertex weights. The arcs in the graph are only used for visualization. This leads to a compact representation of the configuration space and provides a computationally efficient and dense indexing scheme. The localization of inter configurational matrix elements are determined directly from the graph by means of segments and shapes similar to other graphical approaches. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Synergistic Effect Between Ouabain and Glucocorticoids for the Induction of Thymic Atrophy
Authors: Rodrigues-Mascarenhas Sandra , dos Santos Neusa Fernandes , Rumjanek Vivian M.
Published: June 2006

The present report shows that thymocyte death, induced by glucocorticoids, may be modulated in vivo by ouabain. Young, ten days old, mice injected with 140 mg/kg sodium succcinate of hydrocortisone (HC) intraperitonially (i.p.) displayed, 24 h after the injection, a decrease in thymus size and cellular content, an effect that was magnified when ouabain (OUA) 0.56 mg/kg, i.p. was given 1 h prior to the HC injection. Ouabain per se was not capable of producing these changes. Both HC and the combination OUA plus HC induced the death of immature double positive lymphocytes (CD4+CD8+) whereas CD69+ cells survived both treatments. An increase in annexin positive cells and a decrease in mitochondrial membrane potential, assessed by cytofluorimetry, using the fluorescent dye DiOC6, was observed in thymocytes from HC treated animals indicating apoptosis of these cells. Furthermore, a synergistic effect between OUA and HC was also observed using this parameter. The synergy observed in the thymus of animals treated with glucocorticoids and OUA might occur under stress, when both hormones are released, or in situations when ouabain is administered exogenously in a moment of the circadian cycle when glucocorticoid levels are elevated. However the impact of this effect on the immune response is still unknown.
Effects of avian grazing on the algal community and small invertebrates in the rocky intertidal zone
Authors: Hori Masakazu , Noda Takashi , Nakao Shigeru
Published: June 2006

In this study of a rocky intertidal habitat in northern Japan, feeding by avian consumers had significant effects on algal assemblages and small herbivorous invertebrates. The effects of the birds on algae were different from those of invertebrate grazers such as urchins and gastropods. The abundance of the dominant algal species decreased during the grazing period, increased again after the grazing period, and indirectly affected algal species richness and evenness. Avian grazing also decreased the density of tube‐dwelling amphipods on the dominant alga, but did not change the density of mobile and free‐living isopods. These results suggest that avian grazers may act as habitat modifiers rather than exploitative competitors for the small herbivorous crustaceans. Avian herbivores consumed only the upper parts of large algal fronds, apparently reducing the amount of suitable microhabitat for the small herbivorous crustaceans, which are subject to a variety of physical or biological stress. Thus, avian herbivores function as ecosystem engineers, regulating community structure in a manner different to invertebrate herbivores in rocky intertidal habitats.
Hypoxia‐induced fatty acid transporter translocation increases fatty acid transport and contributes to lipid accumulation in the heart
Authors: Chabowski Adrian , Górski Jan , Calles-Escandon Jorge , Tandon Narendra N. , Bonen Arend
Published: June 2006

Protein‐mediated LCFA transport across plasma membranes is highly regulated by the fatty acid transporters FAT/CD36 and FABPpm. Physiologic stimuli (insulin stimulation, AMP kinase activation) induce the translocation of one or both transporters to the plasma membrane and increase the rate of LCFA transport. In the hypoxic/ischemic heart, intramyocardial lipid accumulation has been attributed to a reduced rate of fatty acid oxidation. However, since acute hypoxia (15 min) activates AMPK, we examined whether an increased accumulation of intramyocardial lipid during hypoxia was also attributable to an increased rate of LCFA uptake as a result AMPK‐induced translocation of FAT/CD36 and FABPpm. In cardiac myocytes, hypoxia (15 min) induced the redistribution of FAT/CD36 from an intracellular pool (LDM) (−25%, P
< 0.05) to the plasma membranes (PM) (+54%, P
< 0.05). Hypoxia also induced an increase in FABPpm at the PM (+56%, P
< 0.05) and a concomitant FABPpm reduction in the LDM (−24%, P
< 0.05). Similarly, in intact, Langendorff perfused hearts, hypoxia induced the translocation of a both FAT/CD36 and FABPpm to the PM (+66% and +61%, respectively, P
< 0.05), with a concomitant decline in FAT/CD36 and FABPpm in the LDM (−24% and −23%, respectively, P
< 0.05). Importantly, the increased plasmalemmal content of these transporters was associated with increases in the initial rates of palmitate uptake into cardiac myocytes (+40%, P
< 0.05). Acute hypoxia also redirected palmitate into intracellular lipid pools, mainly to PL and TG (+48% and +28%, respectively, P
< 0.05), while fatty acid oxidation was reduced (−35%, P
< 0.05). Thus, our data indicate that the increased intracellular lipid accumulation in hypoxic hearts is attributable to both: (a) a reduced rate of fatty acid oxidation and (b) an increased rate of fatty acid transport into the heart, the latter being attributable to a hypoxia‐induced translocation of fatty acid transporters.
Effects of perinatal stress on the anxiety‐related behavior of the adolescence mouse
Authors: Nishio H. , Tokumo K. , Hirai T.
Published: June 2006

We evaluated the effects of sound noise or forced swim stress applied to pregnant mice or to neonatal mice on the anxiety‐related behavior using the elevated plus‐maze test performed during the age of 5 weeks. The forced swim stress applied at the late gestation period, days 10–18 of pregnancy, caused a significant reduction of the body weight gain of the dams. However, the anxiety‐related behavior of the male and female offspring were not affected by the antenatal stress treatment. When the forced swim stress was applied to the neonatal mice during the late lactation period, 14–18 days after birth, the male mice showed an elevated level of anxiolytic behavior accompanying the reduction of the emotion‐related motor activity. The anxiety‐related behavior of the female mice was not affected by the stress treatment. Furthermore, we applied the sound noise or forced swim stress to the neonatal mice immediately after the weaning, 21–25 days after birth. The stress applied after the weaning period had no effect on the anxiety‐related behavior. These results suggested that the stress applied during the lactation period, but not that during the antenatal period, nor after the weaning period, might have gender‐dependently reduced the anxiety level of the male mouse. It was shown that the effects of perinatal stress on the anxiety‐related behavior of the adolescent mouse varied according to the period of application and gender. The hypothesis that gender‐dependent abnormalities in neurodevelopment might be caused by the excess stress applied to the breast‐fed infant is of importance in elucidating the relationship between the psychoneurotic disorder in childhood and the environment stress of the breast‐fed infant.
Public Transcripts Expressed in Theatres of Cruelty: the Royal Graves at Ur in Mesopotamia
Authors: Dickson D. Bruce
Published: June 2006

The interpretation of the Royal Graves at Ur, Mesopotamia, by their excavator, Sir Leonard Woolley, has long been accepted. Woolley implies that the people sacrificed along with the dynasts went willingly to their deaths out of loyalty, devotion, and faith in the dead monarchs; but other interpretations are plausible. One is that these graves are the remains of dramas portraying a ‘public transcript’ played out in a public theatre of cruelty staged by rulers claiming divine status. State power united with supernatural authority can create extraordinarily powerful ‘sacred or divine kingdoms’; but ‘sacred’ or ‘divine’ kings need continuous contact with the supernatural and affirmation of their divinity. They are obliged to practise acts of public mystification, of which the Royal Graves appear to be examples. Ur's kings may indeed have been strong and their subjects loyal, but it is equally likely that they were weak and vulnerable and that they practised ritual sacrifice to terrorize a restive citizenry and convince themselves and others of their right to rule. Other examples of public transcripts made manifest in state-sponsored theatres of cruelty confirm that the Royal Graves at Ur are not unique but represent a phenomenon of wider historical generality.
The Neanderthals: a Social Synthesis
Authors: Davies Robert , Underdown Simon
Published: June 2006

The Neanderthals have long fascinated archaeologists and anthropologists alike. Similarity to us coupled with clear differences has produced endless theorizing. This article reviews the background to such ideas. It examines the current lines of thought about Neanderthals and explores the validity of the conclusions. The ultimate aim is the construction of a social synthesis, a solid foundation upon which the validity of inferences regarding Neanderthal cognitive ability and behavioural complexity may be examined.
Dating the Dreaming? Creation of Myths and Rituals for Mounds along the Northern Australian Coastline
Authors: Hiscock Peter , Faulkner Patrick
Published: June 2006

Shell mounds ceased to be built in many parts of coastal northern Australia about 800–600 years ago. They are the subject of stories told by Aboriginal people and some have been incorporated in ritual and political activities during the last 150 years. These understandings emerged only after termination of the economic and environmental system that created them, 800–600 years ago, in a number of widely separated coastal regions. Modern stories and treatments of these mounds by Aboriginal people concern modern or near-modern practices. Modern views of the mounds, their mythological and ritual associations, may be explained by reference to the socioeconomic transitions seen in the archaeological record; but the recent cultural, social and symbolic statements about these places cannot inform us of the process or ideology concerned with the formation of the mounds. Many Aboriginal communities over the last half a millennium actively formed understandings of new landscapes and systems of land use. Attempts to impose historic ideologies and cosmologies on earlier times fail to acknowledge the magnitude and rate of economic and ideological change on the tropical coastline of Australia.
Ein 29-jähriger Patient mit dem Bild einer Takayasu-Arteriitis
Authors: Rüppell  , Mickley  , Seidel  , Thiele  , Hartmann
Published: June 2006

Ein 29 Jahre alter Patient stellte sich nach einem Kollapsereignis sowie rezidivierender Schwindelsymptomatik vor. In der klinischen Untersuchung fielen ein Strömungsgeräusch über der Arteria carotis communis linksseitig sowie fehlende Armpulse beidseitig auf. Duplexsonographisch sowie MR-angiographisch und mittels brachiocephaler Angiographie wurden höhergradige Stenosen und Verschlüsse der extracraniellen hirnversorgenden Arterien dokumentiert. In der Labordiagnostik fielen lediglich eine beschleunigte Blutsenkungsgeschwindigkeit sowie ein deutlich erhöhtes C-reaktives Protein auf. Die rheumatologische Labordiagnostik hatte keinen auffälligen spezifischen Befund ergeben. Es wurde eine antiinflammatorische Therapie (Prednisolon), die mit einer immunsuppressiven Behandlung (Azathioprin) kombiniert wurde, eingeleitet. Bereits 12 Tage nach Therapiebeginn konnten duplexsonographisch und laborchemisch erste positive Therapieeffekte nachgewiesen werden. Bei Symptomen von Stenosen und Verschlüssen großer, vom Aortenbogen abgehender Gefäße (z.B. nicht tastbare Radialispulse), sollte differenzialdiagnostisch an das Vorliegen einer Vaskulitis gedacht werden. Die Takayasu-Vaskulitis ist insbesondere beim Fehlen typischer Vaskulitis-Marker von anderen Vaskulitiden abzugrenzen. Die MR-Angiographie hat sich in letzter Zeit als wertvoll in der Beurteilung der Wandbeschaffenheit der Aorta, ihrer Abgänge und anderer großer Arterien erwiesen.
Positionspapier zur Indikation und Durchführung der interventionellen Behandlung extrakranieller Karotisstenosen
Authors: Mudra  , Büchele  , Mathias  , Schuler  , Sievert  , Theiss
Published: June 2006

Stenosen der Arteria carotis führen in Deutschland etwa 30 000 mal pro Jahr zu einem Schlaganfall. Neben der durch randomisierte multizentrische Studien etablierten chirurgischen Beseitigung von extrakraniellen Stenosen der Arteria carotis wird die perkutane Ballondilatation kombiniert mit einer Stentimplantation immer häufiger durchgeführt. Dieses Konsensus-Papier beschreibt den aktuellen Stand wissenschaftlicher Studien und kontrollierter Behandlungsregister dieses alternativen Therapieverfahrens und nimmt Stellung zu seiner Indikation und Durchführung. Mittels einer Medline-Recherche bis August 2005 wurden alle prospektiven randomisierten Studien mit klinischen Endpunkten sowie kontrollierte Therapieregister mit mehr als 500 eingeschlossenen Patienten berücksichtigt. Die zwei abgeschlossenen randomisierten Vergleiche zwischen operativer und katheterinterventioneller Therapie (CAVATAS und SAPPHIRE) ergaben in Bezug auf das neurologische outcome keinen signifikannten Unterschied. Die großen multizentrischen Register resultierten im kombinierten Endpunkt (Tod und/oder Schlaganfall nach 30 Tagen) mit einer Inzidenz zwischen 3.3 und 6.91%. Die Ergebnissen der perkutanen Behandlung der Karotisstenose sind damit denen der operativen Thrombendarteriektomie vergleichbar und erfüllen hinsichtlich der periinterventionellen Komplikationsraten die Anforderungen, die an das operative Referenzverfahren gestellt werden. Unter der Voraussetzung, dass diese Ergebnisqualität erzielt wird, lassen sich derzeit für die Karotisstentimplantation abhängig von Symptomatik und perioperativem Risiko des Patienten sowie Stenosegrad Empfehlungsklassen der Kategorie I und II auf einem Evidenzniveau der Kategorie B bzw. C ableiten.
Detailed plaque texture analysis as the alternate method of ultrasound image analysis in predicting the risk of intraoperative microembolism and perioperative complications
Authors: Madycki  , Staszkiewicz
Published: June 2006

Background: The aim of the study was to assess the value of an alternative method of carotid plaque ultrasound image analysis in relation to the perioperative complications and the main risk factor: the microembolism (ME). Material and methods: 96 plaques were evaluated following carotid endarterectomy. Preoperatively, each plaque was screened by ultrasound and assessed by means of 2 computer assisted methods. All patients were evaluated for ME (measured as hits) intraoperatively. The removed plaques were assessed visually (intraoperative assessement) and histologically. A number of risk factors were included as a final outcome event for the purpose of multivariate regression analysis. Results: Detailed plaque texture analysis (DPTA) predicts best the risk of perioperative complications and ME (p = 0.029 and p = 0.028 respectively). The results of the standard gray-scale median (GSM) analysis did not reach the statistical significance (p > 0.1). The predictive value of the model (ROC) was 0.88. The multivariate model for ME revealed that from the level of > 5 HITS, a rapid increase in the risk of perioperative complications (rise of 5% by every 1 hit) is seen and correlates well with the DPTA. ROC was 0.77. A direct correlation between the DPTA and perioperative ME was shown. Conclusions: DPTA analysis of a carotid plaque is more predictive of the likelihood of microembolism than the GSM analysis. There is a direct correlation between the perioperative ME and plaque morphology, as assessed by DPTA. This supports the need for further refinements in noninvasive analysis of carotid plaques.
GeoFramework: Coupling multiple models of mantle convection within a computational framework
Authors: Tan E. , Choi E. , Thoutireddy P. , Gurnis M. , Aivazis M.
Published: June 2006

Solver coupling can extend the capability of existing modeling software and provide a new venue to address previously intractable problems. A software package has been developed to couple geophysical solvers, demonstrating a method to accurately and efficiently solve multiscale geophysical problems with reengineered software using a computational framework (Pyre). Pyre is a modeling framework capable of handling all aspects of the specification and launching of numerical investigations. We restructured and ported CitcomS, a finite element code for mantle convection, into the Pyre framework. Two CitcomS solvers are coupled to investigate the interaction of a plume at high resolution with global mantle flow at low resolution. A comparison of the coupled models with parameterized models demonstrates the accuracy and efficiency of the coupled models and illustrates the limitations and utility of parameterized models.
Excess radiocarbon constraints on air‐sea gas exchange and the uptake of CO2 by the oceans
Authors: Naegler T. , Ciais P. , Rodgers K. , Levin I.
Published: June 2006

We re‐assess the constraints that estimates of the global ocean excess radiocarbon inventory (IE) place on air‐sea gas exchange. We find that the gas exchange scaling parameter aq cannot be constrained by IE alone. Non‐negligible biases in different global wind speed data sets require a careful adaptation of aq to the wind field chosen. Furthermore, aq depends on the spatial and temporal resolution of the wind fields. We develop a new wind speed‐ and inventory‐normalized gas exchange parameter aqN which takes into account these biases and which is easily adaptable to any new estimate of IE. Our study yields an average estimate of aq of 0.32 ± 0.05 for monthly mean winds, lower than the previous estimate (0.39) from Wanninkhof (1992). We calculate a global annual average piston velocity for CO2 of 16.7 ± 2.9 cm/hr and a gross CO2 flux between atmosphere and ocean of 73 ± 10 PgC/yr, significantly lower than results from previous studies.