bluuebunny/crossref_metadata_2025 huggingface dataset:
Therapeutic factors in dysphoric disorders
Authors: Beutler Larry E. , Castonguay Louis G. , Follette William C.
Published: March 2006

The working group on the treatment of dysphoric disorders focused on ways to integrate variables and qualities that optimize treatment effects for this clinical population. The variables examined represent three aspects or domains of the treatment context that effect positive change. These included aspects of the patient and therapist (participant factors), those relating to the development and role of the therapeutic relationship (relationship factors), and those that defined the application of formal interventions that are implemented by the therapist (techniques factors). The treatment literature on dysphoric populations was reviewed and a variety of relationships was identified, which then were translated into principles that are thought to enhance treatment effects. The principles representing the three domains of this review are then collected, in this article, into a set of cohesive suggestions for treating patients whose problems are characterized by major or minor depression, alone or as a comorbid condition. © 2006 Wiley Periodicals, Inc. J Clin Psychol 62: 639–647, 2006.
Inhibition of phospholipase C‐β1‐mediated signaling by O‐GlcNAc modification
Authors: Kim Yun‐Hee , Song Minseok , Oh Young‐Seok , Heo Kyun , Choi Jung‐Woong , Park Ji‐Man , Kim Sun‐Hee , Lim Seyoung , Kwon H. Moo , Ryu Sung Ho , Suh Pann‐Ghill
Published: March 2006

Here we report inhibition of phospholipase C‐β1 (PLC‐β1)‐mediated signaling by post‐translational glycosylation with β‐N‐acetylglucosamine (O‐GlcNAc modification). In C2C12 myoblasts, isoform‐specific knock‐down experiments using siRNA showed that activation of bradykinin (BK) receptor led to stimulation of PLC‐β1 and subsequent intracellular Ca2+ mobilization. In C2C12 myotubes, O‐GlcNAc modification of PLC‐β1 was markedly enhanced in response to treatment with glucosamine (GlcNH2), an inhibitor of O‐GlcNAase (PUGNAc) and hyperglycemia. This was associated with more than 50% inhibition of intracellular production of IP3 and Ca2+ mobilization in response to BK. Since the abundance of PLC‐β1 remained unchanged, these data suggest that O‐GlcNAc modification of PLC‐β1 led to inhibition of its activity. Moreover, glucose uptake stimulated by BK was significantly blunted by treatment with PUGNAc. These data support the notion that O‐GlcNAc modification negatively modulates the activity of PLC‐β1. J. Cell. Physiol. © 2006 Wiley‐Liss, Inc.
Probing nucleocytoplasmic transport by two‐photon activation of PA‐GFP
Authors: Chen Yan , Macdonald Patrick J. , Skinner Joseph P. , Patterson George H. , Müller Joachim D.
Published: March 2006

Two‐photon activation of photoactivatable green fluorescent protein (PA‐GFP) provides a unique tool for probing cellular transport processes, because activation is strictly limited to the subfemtoliter optical volume of the two‐photon spot. We demonstrate two‐photon activation of PA‐GFP immobilized in a gel and freely diffusing within cells and recover a quadratic power dependence. Illumination at 820 nm allows simultaneous activation and fluorescence monitoring by two‐photon excitation. Alternatively, we activate PA‐GFP using two‐photon excitation and monitor the fluorescence of the photoconverted product with one‐photon excitation. We probe nucleocytoplasmic transport through the nuclear pore complex of COS‐1 cells, by observing the time‐dependent fluorescence at various locations within the cell after two‐photon activation of PA‐GFP in the nucleus and in the cytoplasm. Two‐photon activation of a tandem construct of two PA‐GFPs showed a markedly slower rate of crossing through the nuclear pore. Analysis based on a restricted diffusion model yields a nuclear pore radius of 4.5 nm, which is in good agreement with previously reported values. This application demonstrates the attractive features of two‐photon photoactivation over traditional techniques, such as photobleaching, for studying transport processes in cells. Microsc. Res. Tech. 69:220–226, 2006. © 2006 Wiley‐Liss, Inc.
Photoswitchable cyan fluorescent protein as a FRET donor
Authors: Souslova Ekaterina A. , Chudakov Dmitriy M.
Published: March 2006

Among a variety of fluorescent proteins available today, there is a lack of suitable markers with excitation/emission in the violet/blue part of visible spectrum. Recently, we reported on photoswitchable cyan fluorescent protein (PS‐CFP), which represents monomeric high‐contrasting photactivatable label for in vivo protein movement tracking. However, PS‐CFP demands high intensity of light for the photoswitching. Therefore it can be employed as a common fluorescent tag at conventional light intensities, which cause negligible or zero photoactivation. High pH stability and unique positioning of excitation/emission peaks make it a worthy supplement to the existing palette of fluorescent proteins. Here we use PS‐CFP fusion with a yellow fluorescent protein phiYFP to show that PS‐CFP is a promising donor partner for the fluorescence resonance energy transfer (FRET). A remarkable phenomenon is that PS‐CFP donor fluorescence turned to be essentially stable with and without FRET, while acceptor emission demonstrated record dynamic range of up to 7.8‐fold. This makes the FRET pair presented a useful tool for the single color high throughput screenings. Here we also propose ways for further PS‐CFP enhancing, aiming to develop bright cyan fluorescent protein with unique spectral characteristics. Microsc. Res. Tech. 69:207–209, 2006. © 2006 Wiley‐Liss, Inc.
Single molecule fluorescence imaging of the photoinduced conversion and bleaching behavior of the fluorescent protein Kaede
Authors: Schäfer S.P. , Dittrich P.S. , Petrov E.P. , Schwille P.
Published: March 2006

Photoconversion and photobleaching behavior of the fluorescent protein Kaede immobilized in polyacrylamide gel matrix at room temperature was studied by single molecule wide‐field fluorescence microscopy. Photobleaching kinetics of Kaede molecules upon excitation at 488 nm showed slight heterogeneity, suggesting the presence of different protein conformations and/or the distribution of local environments in the gel matrix. Statistical analysis of intensity trajectories of single molecules revealed four major types of fluorescence dynamics behavior upon short illumination by a violet light pulse (405 nm). In particular, two types of photoswitching behavior were observed: the green‐to‐red photoconversion (4% of Kaede molecules) and the photoactivation of green fluorescence without emission of red fluorescence (13%). Two other major groups show neither photoconversion nor red emission and demonstrate photoinduced partial deactivation (43%) and partial revival (30%) of green fluorescence. The significantly lower green‐to‐red conversion ratio as compared with bulk measurements in aqueous solution might be induced by the immobilization of the protein molecules within a polyacrylamide gel. Contrary to Ando et al. (Proc Natl Acad Sci 2002;99:12651–12656), we found a significant increase in green fluorescence emission upon illumination with 405‐nm light, which is typical for GFP and related proteins. Microsc. Res. Tech. 69: 210–219, 2006. © 2006 Wiley‐Liss, Inc.
Improving autofluorescent proteins: Comparative studies of the effective brightness of Green Fluorescent Protein (GFP) mutants
Authors: Jung Gregor , Zumbusch A
Published: March 2006

We study the photophysical behavior of 8 mutants of Green Fluorescent Protein (GFP) using fluorescence correlation spectroscopy (FCS) on the single molecule level and double resonance excitation of bulk samples. Experimental data reported here and the previously published data on the RH/R− equilibrium and fluorescence quantum yields ΦFl (Jung et al., 2005; Biophys J 88:1932–1947) are analyzed with respect to single molecule as well as conventional fluorescence microscopy. The fraction of GFP molecules in a dark state, [D], reduces the effective absorption cross section under photostationary conditions. The determination of the excitable fraction [B] and its fluorescence quantum yield ΦFl gives the effective brightness Φeff. Our results show that in its wavelength range, eGFP is, among the GFPs, the best fluorophore for most microscopic applications. However, in the red shifted YFP‐proteins, there is still potential for improvement, since a pronounced dark state population is detectable in all mutants investigated so far. We propose to use the mutant T203Y/E222Q in imaging studies, whenever the expression yield is not a limiting factor. In FCS experiments, where the useful concentration range of the expressed molecules is restricted to concentrations below micromolarity, our data suggest the use of wt‐GFP or mutant T203Y, as these represent photochemical buffers. Both mutants might surpass the limitations given by out‐of‐focus bleaching in live cell microscopy. Microsc. Res. Tech. 69:175–185, 2006. © 2006 Wiley‐Liss, Inc.
Accessible proteomics space and its implications for peak capacity for zero‐, one‐ and two‐dimensional separations coupled with FT‐ICR and TOF mass spectrometry
Authors: Frahm Jennifer L. , Howard Brian E. , Heber Steffen , Muddiman David C.
Published: March 2006

The number and wide dynamic range of components found in biological matrixes present several challenges for global proteomics. In this perspective, we will examine the potential of zero‐dimensional (0D), one‐dimensional (1D), and two‐dimensional (2D) separations coupled with Fourier‐transform ion cyclotron resonance (FT‐ICR) and time‐of‐flight (TOF) mass spectrometry (MS) for the analysis of complex mixtures. We describe and further develop previous reports on the space occupied by peptides, to calculate the theoretical peak capacity available to each separations‐mass spectrometry method examined. Briefly, the peak capacity attainable by each of the mass analyzers was determined from the mass resolving power (RP) and the m/z space occupied by peptides considered from the mass distribution of tryptic peptides from National Center for Biotechnology Information's (NCBI's) nonredundant database. Our results indicate that reverse‐phase‐nanoHPLC (RP‐nHPLC) separation coupled with FT‐ICR MS offers an order of magnitude improvement in peak capacity over RP‐nHPLC separation coupled with TOF MS. The addition of an orthogonal separation method, strong cation exchange (SCX), for 2D LC‐MS demonstrates an additional 10‐fold improvement in peak capacity over 1D LC‐MS methods. Peak capacity calculations for 0D LC, two different 1D RP‐HPLC methods, and 2D LC (with various numbers of SCX fractions) for both RP‐HPLC methods coupled to FT‐ICR and TOF MS are examined in detail. Peak capacity production rates, which take into account the total analysis time, are also considered for each of the methods. Furthermore, the significance of the space occupied by peptides is discussed. Copyright © 2006 John Wiley & Sons, Ltd.
Does seasonal variation affect hallucinations in PD? a longitudinal study
Authors: Goetz Christopher G. , Li John Michael , Wuu Joanne , Leurgans Sue
Published: March 2006

The objective of this study was to examine the chronobiology of visual hallucinations in Parkinson's disease (PD) patients to test whether hallucinations are more severe during darker months (winter) than summer months. We extracted longitudinal data on the UPDRS Thought Disorder (TD) score, taken as part of regular patient management on sequential visits through a 1‐year cycle in hallucinating PD patients. To reduce the confounding effects of medication adjustments, analysis was restricted to patients with a baseline evaluation that did not involve a medication change. The primary outcome was the seasonal change in hallucination severity, defined as a change in TD score or neuroleptic use. Using Wilcoxon rank‐sum tests, we compared the exacerbation of hallucination by season, focusing on winter (December through February) versus summer (June through August). A total of 51 hallucinating patients met entry criteria, and their longitudinal data were analyzed. There was no difference in hallucination severity with changing season; the level of wintertime exacerbation was no greater than summertime exacerbation (P = 0.42). Although hallucinations frequently develop in dimmed environments and evening hours, the darkness of wintertime does not exacerbate hallucinations in PD subjects on stable medications. Because we found no evidence of seasonal variations, we cannot recommend phototherapy or other strategies affecting chronobiological systems as research priorities to treat PD hallucinations. © 2006 Movement Disorder Society
Assignment of the 1H and 13C NMR signals of some benzofurocoumarins
Authors: Quezada Elías , Santana Lourdes , Uriarte Eugenio
Published: March 2006

The complete 1H and 13C NMR assignment of four 6,7‐benzo‐fused furocoumarins (1–4) and three 3,4‐benzo‐fused furocoumarins (5–7) has been performed using 1D and 2D NMR techniques, including COSY, HMQC and HMBC experiments. Copyright © 2006 John Wiley & Sons, Ltd.
In vitro enzymatic oxidation of a fluorine‐tagged sulfido substrate analogue: a 19F NMR investigation
Authors: Tremblay Amy E. , Buist Peter H. , Hodgson Derek , Dawson Brian , Whittle Ed , Shanklin John
Published: March 2006

1H‐decoupled 19F NMR has been used to monitor the highly regioselective oxidation of a fluorine‐tagged thia‐fatty acid derivative by castor stearoyl‐ACP Δ9 desaturase. The major enzymatic product, after reductive work‐up, was identified as 9‐fluoro‐1‐nonanol. This compound could be easily distinguished from substrate and a 9‐sulfoxy by‐product on the basis of its 19F NMR chemical shift and spiking experiments using authentic standards. Structural assignment of the cleavage product was confirmed by GC‐MS analysis of the enzymatic products. Copyright © 2006 John Wiley & Sons, Ltd.
Standardization of chemical shifts of TMS and solvent signals in NMR solvents
Authors: Hoffman Roy E.
Published: March 2006

The standard for chemical shift is dilute tetramethylsilane (TMS) in CDCl3, but many measurements are made relative to TMS in other solvents, the proton resonance of the solvent peak or relative to the lock frequency. Here, the chemical shifts of TMS and the proton and deuterium chemical shifts of the solvent signals of several solvents are measured over a wide temperature range. This allows for the use of TMS or the solvent and lock signal as a secondary reference for other NMR signals, as compared with dilute TMS in CDCl3 at a chosen temperature; 25 °C is chosen here. An accuracy of 0.02 ppm is achievable for dilute solutions, provided that the interaction with the solvent is not very strong. The proton chemical shift of residual water is also reported where appropriate. Copyright © 2006 John Wiley & Sons, Ltd.
Oral magnetic resonance imaging contrast agent based on Ilex paraguayensis herbal extract
Authors: Nestle Nikolaus , Pauls Sandra , Wunderlich Arthur
Published: March 2006

In this article we demonstrate the potential of herbal extracts from yerba mate (Ilex paraguayensis) as an oral contrast agent for MRI. At typical drinking concentrations, yerba mate acts as a “biphasic” contrast agent with T1 weighting at short echo times and T2 weighting at echo times greater than about 40 ms. Based on data obtained from X‐ray fluorescence elemental analysis, NMR relaxometry, and ESR we identify the relaxation agent in the extract as a low‐molecular‐weight manganese complex. Yerba mate exhibits an unusually high manganese content that is readily available for hot water extraction. Despite the high elemental manganese levels in I. paraguayensis extract, no manganese‐related toxicity of yerba mate has been observed even among heavy yerba mate drinkers, indicating that the manganese in the extract has only a very low bioavailability. Imaging results on staff and patient volunteers demonstrate good contrasting of the GI tract. The relaxation studies of the contrast agent show a sensitivity to pH that is consistent with imaging results from stomach and small bowel. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
MR coronary angiography in pigs with intraarterial injections of a hyperpolarized 13C substance
Authors: Olsson Lars E. , Chai Chun‐Ming , Axelsson Oskar , Karlsson Magnus , Golman Klaes , Petersson J. Stefan
Published: March 2006

A new diagnostic application of a water‐soluble contrast medium (CM) based on the hyperpolarization of a 13C substance is introduced. The degree of polarization achieved is >30%, which is about a factor of 105 higher than the thermal equilibrium polarization level at 1.5 T. Imaging of hyperpolarized (HP) CM during a cardiac interventional MRI procedure was studied. Catheters were positioned in the left and right coronary arteries of pigs. A coil tuned to 13C was used for nonproton imaging. The HP‐13C CM (∼5 ml, 0.5 M, ∼30% polarization) was injected during projection imaging using a fully balanced steady‐state free precession (SSFP) pulse sequence with and without cardiac gating. The contrast agent‐filled catheter was clearly visible during the procedure. The coronary arteries were well depicted and the signal‐to‐noise ratios (SNRs) were in the range of 10–40. The use of HP‐13C CM may provide a new diagnostic procedure for interventional MRI. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Simple route for synthesis of H‐shaped copolymers
Authors: Han De‐Hui , Pan Cai‐Yuan
Published: March 2006

The H‐shaped copolymers, [poly(L‐lactide)]2polystyrene [poly(L‐lactide)]2, [(PLLA)2PSt(PLLA)2] have been synthesized by combination of atom transfer radical polymerization (ATRP) with cationic ring‐opening polymerization (CROP). The first step of the synthesis is ATRP of St using α,α′‐dibromo‐p‐xylene/CuBr/2,2′‐bipyridine as initiating system, and then the PSt with two bromine groups at both chain ends (Br–PSt–Br) were transformed to four terminal hydroxyl groups via the reaction of Br–PSt–Br with diethanolamine in N,N‐dimethylformamide. The H‐shaped copolymers were produced by CROP of LLA, using PSt with four terminal hydroxyl groups as macroinitiator and Sn(Oct)2 as catalyst. The copolymers obtained were characterized by 1H NMR spectroscopy and gel permeation chromatography. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2794–2801, 2006
Synthesis and properties of novel sulfonated (co)polyimides bearing sulfonated aromatic pendant groups for PEFC applications
Authors: Hu Zhaoxia , Yin Yan , Chen Shouwen , Yamada Otoo , Tanaka Kazuhiro , Kita Hidetoshi , Okamoto Ken‐Ichi
Published: March 2006

Novel sulfonated diamines bearing aromatic pendant groups, namely, 3,5‐diamino‐3′‐sulfo‐4′‐(4‐sulfophenoxy) benzophenone (DASSPB) and 3,5‐diamino‐3′‐sulfo‐4′‐(2,4‐disulfophenoxy) benzophenone (DASDSPB), were successfully synthesized. Novel side‐chain‐type sulfonated (co)polyimides (SPIs) were synthesized from these two diamines, 1,4,5,8‐naphthalene tetracarboxylic dianhydride (NTDA) and nonsulfonated diamines such as 4,4′‐bis(3‐aminophenoxy) phenyl sulfone (BAPPS). Tough and transparent membranes of SPIs with ion exchange capacity of 1.5–2.9 meq g−1 were prepared. They showed good solubility and high thermal stability up to 300 °C. They showed isotropic membrane swelling in water, which was different from the main‐chain‐type and sulfoalkoxy‐based side‐chain‐type SPIs. The relative humidity (RH) and temperature dependence of proton conductivity were examined. At low RH, the novel SPI membranes showed much higher conductivity than the sulfoalkoxy‐based SPIs. They showed comparable or even higher proton conductivity than Nafion 112 in water at 60 °C (>0.10 S cm−1). The membrane of NTDA‐DASDSPB/BAPPS (1/1)‐s displayed reasonably high proton conductivities of 0.05 and 0.30 S cm−1 at 50 and 100% RH, respectively, at 120 °C. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2862–2872, 2006
N,N‐dimethylaminopyridine as initiator in the copolymerization of diglycidylether of bisphenol A with six‐membered cyclic carbonates
Authors: Cervellera Roser , Ramis Xavier , Salla Josep Maria , Mantecón Ana , Serra Angels
Published: March 2006

N,N‐Dimethylaminopyridine (DMAP) was used as initiator to cure mixtures of diglycidylether of bisphenol A (DGEBA) and 1,3‐dioxan‐2‐one (TMC) or 5,5‐dimethyl‐1,3‐dioxan‐2‐one (DMTMC). The curing was studied by differential scanning calorimetry (DSC) and Fourier transform infrared in the attenuated‐total‐reflection mode (FTIR/ATR). FTIR/ATR was used to monitor the competitive reactive processes and to quantify the evolution of the groups involved in the curing. We observed the formation of five‐membered cyclic carbonates and anionic carbonate groups that remain unreacted at the chain ends. The formation of these groups was explained by the attack of the anionic propagation species on the methylene carbon of the carbonate group, which leads to an alkyl‐oxygen rupture. By performing the cure in the thermobalance we could evaluate the loss of CO2 produced in the samples containing carbonates. The kinetics were studied by DSC and analyzed with isoconversional procedures. The addition of carbonates slows down the curing rate. Thermogravimetric analysis (TGA) and dynamic mechanical thermal analysis (DMTA) experiments were used to evaluate the properties of the materials obtained. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2873–2882, 2006
Synthesis and characterization of novel photoactive polymer poly(vinyl alcohol)‐graft‐poly(vinyl naphthalene)
Authors: Rymarczyk‐Machał Monika , Zapotoczny Szczepan , Nowakowska Maria
Published: March 2006

A copolymer of poly(vinyl naphthalene) grafted onto poly(vinyl alcohol) has been synthesized with nitroxide‐mediated controlled radical polymerization. By separating the processes of the generation of grafting sites and polymerization, we can avoid the formation of the homopolymer. Because of its architecture, the polymer is soluble in water, despite the high content of hydrophobic groups. The naphthalene chromophores tend to aggregate, forming hydrophobic microdomains in an aqueous solution. Those aggregates exist in a very constrained environment that leads to extraordinarily large redshifts of both the absorption and emission of the polymer. The polymer acts as an efficient photosensitizer in photoinduced electron transfer. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2675–2683, 2006
Effects of the architecture and environment on polymeric molecular assemblies of novel amphiphilic diblock copolynorbornenes with narrow polydispersity via living ring‐opening metathesis polymerization
Authors: Liaw Der‐Jang , Huang Ching‐Cheng , Kang En‐Tang
Published: March 2006

Diblock copolymers of 5‐(methylphthalimide)bicyclo[2.2.1]hept‐2‐ene (NBMPI) and 1,5‐cyclooctadiene were synthesized by living ring‐opening metathesis polymerization with a well‐defined catalyst {RuCl2(CHPh)[P(C6H11)3]2}. Unhydrogenated diblock copolymers showed two glass transitions due to poly(NBMPI) and polybutadiene segments, such as two glass‐transition temperatures at −86.5 and 115.3 °C for poly1a and −87.2 and 115.3 °C for poly1b. However, only one melting temperature could be observed for hydrogenated copolymers, such as 119.8 °C for poly2a and 121.7 °C for poly2b. The unhydrogenated diblock copolymer with the longer poly(NBMPI) chain (poly1a; temperature at 10% mass loss = 400 °C) exhibited better thermal stability than the one with the shorter poly(NBMPI) chain (poly1b; temperature at 10% mass loss = 385 °C). Two kinds of hydrogenated diblock copolymers, poly2a and poly2b, exhibited relatively poor solubility but better thermal stability than unhydrogenated diblock copolymers because of the polyethylene segments. Poly[(hydrochloride quaternized 2‐norbornene‐5‐methyleneamine)‐b‐butadiene]‐1 (poly3a) was obtained after the hydrolysis and quaternization of poly1a. Dynamic light scattering measurements indicated that the hydrodynamic diameters of the cationic copolymer (poly3a) in water (hydrodynamic diameter = 1580 nm without salt), methanol/water (4/96 v/v; hydrodynamic diameter = 1500 nm without salt), and tetrahydrofuran/water (4/96 v/v; hydrodynamic diameter = 1200 nm without salt) decreased with increasing salt (NaCl) concentration. The effect of temperature on the hydrodynamic diameter of hydrophobically modified poly3a was also studied. The inflection point of the hydrodynamic diameter of poly3a was observed at various polymer concentrations around 30 °C. The critical micelle concentration of hydrophobically modified poly3a was observed at 0.018 g dL−1. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2901–2911, 2006
Effect of 1‐hexene comonomer on polyethylene particle growth and copolymer chemical composition distribution
Authors: Smit Madri , Zheng Xuejing , Brüll Robert , Loos Joachim , Chadwick John C. , Koning Cor E.
Published: March 2006

An investigation of the polymer particle growth characteristics and polymer molecular weight and composition distributions in ethylene homopolymerization and ethylene/1‐hexene copolymerization has been carried out with a catalyst comprising a zirconocene and methylaluminoxane immobilized on a silica support. The presence of 1‐hexene leads to higher productivity and easier fragmentation of the support during particle growth. Crystallization analysis fractionation and gel permeation chromatography analysis of ethylene/1‐hexene copolymers prepared at different polymerization times reveals a broadening of the chemical composition distribution with increasing polymerization time as a result of the gradual formation of a relatively high‐molecular‐weight, ethylene‐rich fraction. The results are indicative of significant monomer diffusion effects in both homopolymerization and copolymerization. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2883–2890, 2006
Reversible addition–fragmentation chain transfer polymerization of methyl methacrylate in emulsion
Authors: Luo Yingwu , Cui Xiufeng
Published: March 2006

Theoretical simulations showed that for controlled/living radical polymerization in an emulsion system, some of the earliest born particles could be superswollen to a size close to 1 μm. We hypothesized that the superswelling of these particles would lead to colloidal instability. Under the guidance of the simulation results, reversible addition–fragmentation chain transfer (RAFT) emulsion polymerization of methyl methacrylate (MMA) was carried out. Experimental results showed that increasing the initiation rate, surfactant level, and targeted molecular weight could improve the colloidal stability of the RAFT polymerization of MMA in an emulsion. The experimental results were in full accord with the theoretical predictions. The poor control of the molecular weight and polydispersity index was found to have a close relationship with the colloidal instability. For the first time, we demonstrated that RAFT polymerization could successfully be implemented with little coagulum, good control of the molecular weight, and a low polydispersity index with the same process used for traditional emulsion polymerization but with higher surfactant levels and initiation rates. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44:2837–2847, 2006
Detailed microscopic study of the full zipA:FtsZ interface
Authors: Moreira I.S. , Fernandes P.A. , Ramos M.J.
Published: March 2006

Protein–protein interaction networks are very important for a wide range of biological processes. Crystallographic structures and mutational studies have generated a large number of information that allowed the discovery of energetically important determinants of specificity at intermolecular protein interfaces and the understanding of the structural and energetic characteristics of the binding hot spots. In this study we have used the improved MMPB/SA (molecular mechanics/Poisson‐Boltzmann surface area) approach that combining molecular mechanics and continuum solvent permits to calculate the free energy differences upon alanine mutation. For a better understanding of the binding determinants of the complex formed between the FtsZ fragment and ZipA we extended the alanine scanning mutagenesis study to all interfacial residues of this complex. As a result, we present new mutations that allowed the discovery of residues for which the binding free energy differences upon alanine mutation are higher than 2.0 kcal/mol. We also observed the formation of a hydrophobic pocket with a high warm spot spatial complementarity between FtsZ and ZipA. Small molecules could be designed to bind to these amino acid residues hindering the binding of FtsZ to ZipA. Hence, these mutational data can be used to design new drugs to control more efficiently bacterial infections. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Modeling and functional analysis of AEBP1, a transcriptional repressor
Authors: Lyons Peter J. , Mattatall Neil R. , Ro Hyo‐Sung
Published: March 2006

Adipocyte enhancer binding protein 1 (AEBP1) is a transcriptional repressor of the aP2 gene, which encodes the adipocyte lipid binding protein and is involved in the differentiation of preadipocytes into mature adipocytes. It is an isoform of aortic carboxypeptidase‐like protein (ACLP), which is a part of the extracellular matrix. AEBP1 and ACLP contain a conserved carboxypeptidase domain which is critical for the function of AEBP1 as a transcriptional repressor. Homology modeling and multiple alignment of AEBP1 homologues were performed to identify putative domains and critical residues that were then deleted or mutated in mouse AEBP1. Expression of wild‐type and mutant AEBP1 proteins in CHO cells was performed, and their function in transcriptional repression was assayed by luciferase assay. All deletion forms of AEBP1 were able to repress transcription driven by the aP2 promoter. The DNA binding domain of AEBP1 was mapped by electrophoretic mobility shift assays to a region of the C‐terminus rich in basic residues. However, wild‐type AEBP1 was not able to interact strongly with DNA, suggesting that AEBP1 might function predominantly as a corepressor, independent of DNA binding. AEBP1 was also found to interact with Ca2+/calmodulin through this basic region, suggesting another mechanism of functional regulation. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Three real‐space discretization techniques in electronic structure calculations
Authors: Torsti T. , Eirola T. , Enkovaara J. , Hakala T. , Havu P. , Havu V. , Höynälänmaa T. , Ignatius J. , Lyly M. , Makkonen I. , Rantala T. T. , Ruokolainen J. , Ruotsalainen K. , Räsänen E. , Saarikoski H. , Puska M. J.
Published: March 2006

A characteristic feature of the state‐of‐the‐art of real‐space methods in electronic structure calculations is the diversity of the techniques used in the discretization of the relevant partial differential equations. In this context, the main approaches include finite‐difference methods, various types of finite‐elements and wavelets. This paper reports on the results of several code development projects that approach problems related to the electronic structure using these three different discretization methods. We review the ideas behind these methods, give examples of their applications, and discuss their similarities and differences. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Recent progress with large‐scale ab initio calculations: the CONQUEST code
Authors: Bowler D. R. , Choudhury R. , Gillan M. J. , Miyazaki T.
Published: March 2006

While the success of density functional theory (DFT) has led to its use in a wide variety of fields such as physics, chemistry, materials science and biochemistry, it has long been recognised that conventional methods are very inefficient for large complex systems, because the memory requirements scale as N 2 and the cpu requirements as N 3 (where N is the number of atoms). The principles necessary to develop methods with linear scaling of the cpu and memory requirements with system size (𝒪(N ) methods) have been established for more than ten years, but only recently have practical codes showing this scaling for DFT started to appear. We report recent progress in the development of the Conquest code, which performs 𝒪(N ) DFT calculations on parallel computers, and has a demonstrated ability to handle systems of over 10000 atoms. The code can be run at different levels of precision, ranging from empirical tight‐binding, through ab initio tight‐binding, to full ab initio , and techniques for calculating ionic forces in a consistent way at all levels of precision will be presented. Illustrations are given of practical Conquest calculations in the strained Ge/Si(001) system. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Lagrange‐function approach to real‐space order‐N electronic‐structure calculations
Authors: Varga Kálmán , Pantelides S. T.
Published: March 2006

The Lagrange functions are a family of analytical, complete, and orthonormal basis sets that are suitable for efficient, accurate, real‐space, order‐N electronic‐structure calculations. Convergence is controlled by a single monotonic parameter, the dimension of the basis set, and computational complexity is lower than that of conventional approaches. In this paper we review their construction and applications in linear‐scaling electronic‐structure calculations. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Density functional studies of molecular magnets
Authors: Postnikov Andrei V. , Kortus Jens , Pederson Mark R.
Published: March 2006

After a general introduction into the field of molecular magnets the discussion focuses on a more specific description of their most important representative species, single‐molecule magnets incorporating transition metal ions. We overview traditional model approaches for the phenomenological description of such systems and outline some ways used to parameterize the corresponding models from experiment and from first‐principle calculations. The latter can be either multi‐determinantal quantum chemical schemes or those based on the density functional theory. In particular we discuss Heisenberg exchange parameters and magnetic anisotropy constants. As a practical example, an introduction into problems and properties of some single‐molecule magnets which gained much attention within last years, namely Mn12‐acetate, “Fe8” and “V15” systems, is given. This introduction into systems is followed by a critical comparison of calculation schemes based on the density functional theory that are particularly well suited for the study of molecular magnets. For the above systems we select some benchmark results, obtained by different methods. Finally, we outline our recent progress in the study of other single‐molecule magnets, including six‐membered “ferric wheels”, “ferric stars” and “Ni4” molecules, which we studied with the use of first‐principles methods Siesta and NRLMOL. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A minute to learn and a lifetime to master: Implications of the poker craze for college campuses
Authors: Hardy Thomas W.
Published: March 2006

This chapter explores the proliferation of poker (both live and online) and discusses how campuses have responded to this activity. The chapter concludes with some implications for practice and further research.
Effect of mouse Sim2 gene on the cell cycle of PC12 cells
Authors: Meng Xianfang , Shi Jing , Peng Bin , Zou Xiaojing , Zhang Chun
Published: March 2006

Sim2 gene plays an important role in the pathogenesis of Down syndrome (DS). To observe the effect of mouse Sim2 (mSim2) on the cell cycle of PC12 cells in vitro and explore the role of Sim2 in the pathogenesis of DS, we cloned the full open reading frame of mSim2 into the pcDNA3 vector and transfected it into PC12 cells, before analysing the effect of mSim2 on the cell cycle. A eukaryotic expression vector of mSim2 (pcDNA3‐mSim2) was successfully constructed. There was notable expression of mSim2 mRNA in the cells transfected with pcDNA3‐Sim2. Flow cytometry showed that there were more cells in G0/G1 phase in the Sim2‐transfected cells than that in the controls (P < 0.01), and significantly fewer in G2/M phase (P < 0.01). The mRNA and protein expressions of cyclin E decreased in the Sim2‐transfected cells, while p27 expression increased significantly (P < 0.01). It is concluded that Sim2 may play an important role in the pathogenesis of DS by inhibiting the cell cycle, which is related to the decreased expression of cyclin E and increased expression of p27.
EDAC fixation increases the demonstrability of biogenic amines in the unicellular Tetrahymena: A flow cytometric and confocal microscopic comparative analysis
Authors: Csaba G. , Kovács P. , Pállinger É.
Published: March 2006

Earlier experiments demonstrated the presence of hormones of the higher ranked animals in Tetrahymena. In the present experiments two fixatives, paraformaldehyde, which is commonly used and a carbodiimide, EDAC that was recommended by Panula et al. for the immunocytochemistry of histamine, are compared in Tetrahymena for the demonstration of histamine and serotonin by using flow cytometry and confocal microscopy. Both hormone levels were significantly higher after EDAC fixation; serotonin almost doubled and histamine was more than fivefold. The confocal microscopic pictures were clearer and the hormones' localization was easier. The results support earlier observations on the presence of these hormones in Tetrahymena and points to the advantage of EDAC fixation for demonstrating these hormones immunocytochemically.
Newly developed primary culture of rat visceral adipocytes and their in vitro characteristics
Authors: Shimizu Kyoko , Sakai Masato , Ando Mamiko , Chiji Hideyuki , Kawada Teruo , Mineo Hitoshi , Taira Toshio
Published: March 2006

We have recently developed a primary culture system for visceral adipocytes (VAs) using stomal‐vascular cells (SVCs) isolated from the mesenteric fat tissue of male Sprague—Dawley rats of 3–5 weeks of age. Modified Dulbecco's modified Eagle medium (DMEM)/F12 containing 17 μM pantothenic acid, 33 μM biotin, 100 μM ascorbic acid, 1 μM octanoic acid, 50 nM triiodothyronine, 10 μg/ml insulin, 10% newborn calf serum (NCS), 100 units/ml penicillin and 100 μg/ml streptomycin was used as a basal culture medium, which did not contain any synthetic compounds usually used to promote adipogenesis, such as indomethacin, dexamethasone, or peroxisome proliferator‐activated receptor (PPAR)‐γ agonists. The SVCs differentiated and proliferated efficiently, and formed a confluent monolayer in 3 days. The VAs accumulated lipids droplets in their cytoplasm at ∼7 days. The differentiation rate from applied SVCs to mature adipocytes was >80% per culture. Adiponectin concentration in the medium increased from Day 5 to Day 7. Application of lipid emulsion stimulated maturation of the SVCs into VAs, as well as subsequent lipid accumulation. Norepinephrine (2 × 10−5 mM) reduced the size of lipid particles and decreased triglyceride (TG) content in the matured adipocytes at 30 min. These results indicate that the new culture system is sufficient to maintain the physiological activity of visceral adipose tissue similar to that in vivo, making it an appropriate and useful tool for basic and applied research on obesity.
Post-traumatic stress reactions of children and adolescents exposed to the Athens 1999 earthquake
Authors: Giannopoulou Ioanna , Strouthos Marios , Smith Patrick , Dikaiakou Anastasia , Galanopoulou Vasiliki , Yule William
Published: March 2006

This study was undertaken 6–7 months after the 1999 Athens earthquake with the aim of exploring the differences in post-traumatic stress disorder (PTSD), anxiety and depression symptoms between a group of children exposed to earthquake with a group of children not exposed to it, but with both groups potentially exposed to the same levels of post-earthquake adversities. The study included 2037 children, aged 9–17 years, who were assessed with self-completed questionnaires. The directly exposed group (N = 1752) had significantly higher anxiety and PTSD scores than the indirectly exposed group (N = 284), but no significant group differences were found in depression scores. Girls in both groups reported significantly more PTSD, anxiety and depressive symptoms than boys. Younger children reported significantly more PTSD and anxiety symptoms than the older ones. No significant interactions were found between direct exposure to earthquake, age group and gender. The severity of PTSD symptoms was most strongly predicted by greater perceived threat during the earthquake, whereas depression was most strongly predicted by the level of post-earthquake adversity. The severity of anxiety symptoms was most strongly predicted by female gender. These findings are discussed in relation to the need for screening and intervention following earthquake events.
Effects of atypical and typical antipsychotic treatments on sexual function in patients with schizophrenia: 12-month results from the Intercontinental Schizophrenia Outpatient Health Outcomes (IC-SOHO) study
Authors: Dossenbach Martin , Dyachkova Yulia , Pirildar Sebnem , Anders Martin , Khalil Afaf , Araszkiewicz Aleksander , Shakhnovich Tamara , Akram Aly , Pecenak Jan , McBride Margaret , Treuer Tamas
Published: March 2006

Purpose

Sexual dysfunction in patients with schizophrenia can reduce quality of life and treatment compliance. This report will compare the effects of selected atypical and typical antipsychotics on sexual function in a large, international population of outpatients with schizophrenia who were treated over 1 year.

Subjects and methods

Outpatients with schizophrenia, who initiated or changed antipsychotic treatment, and entered this 3-year, prospective, observational study were classified according to the monotherapy prescribed at baseline: olanzapine (N = 2638), risperidone (N = 860), quetiapine (N = 142) or haloperidol (N = 188).

Results

Based on patient perception, the odds of experiencing sexual dysfunction during 1 year of therapy was significantly lower for patients treated with olanzapine and quetiapine when compared to patients who received risperidone or haloperidol (all P ≤ 0.001). Females on olanzapine (14%) or quetiapine (8%) experienced a lower rate of menstrual irregularities, compared to females on risperidone (23%) or haloperidol (29%). Significant discordance was evident between patient reports and psychiatrist perception of sexual dysfunction, with psychiatrists underestimating sexual dysfunction (P ≤ 0.001).

Conclusions

These findings indicate clinically relevant differences exist in the sexual side effect profiles of these selected antipsychotics. These factors should be considered when selecting the most appropriate treatment for outpatients with schizophrenia.
Public attitudes towards mental patients: a comparison between Novosibirsk, Bratislava and German cities
Authors: Schomerus Georg , Matschinger Herbert , Kenzin Denis , Breier Peter , Angermeyer Matthias C.
Published: March 2006

Purpose

– It is commonly assumed that reforms in the sector of psychiatric care have contributed to reducing the stigma attached to mental illness. In order to examine whether a relation between the psychiatric care set-up and stigmatisation of the patients exists we compared public attitudes towards mental patients in three countries at differing stages of progress in psychiatric reform.

Methods

– Population surveys on public attitudes towards mental patients were conducted in Novosibirsk (Russia) and Bratislava (Slovakia). The data were compared with those from a population survey that had recently been carried out in Germany. In all three surveys the same sampling procedure and fully structured interview were used. Public attitude towards mental patients was elicited using a perceived devaluation-discrimination measure.

Results

– Psychiatric patients face considerable rejection in all three locations in question. Overall, the degree of perceived devaluation and discrimination was similar in all countries with a significant, but marginal tendency towards stronger devaluation of mental patients in Germany.

Conclusion

– Our results do not support a strong relationship between psychiatric reform and mental illness stigma.
The regulatory PII protein controls arginine biosynthesis in Arabidopsis
Authors: Ferrario-Méry Sylvie , Besin Evelyne , Pichon Olivier , Meyer Christian , Hodges Michael
Published: March 2006

In higher plants, PII is a nuclear‐encoded plastid protein which is homologous to bacterial PII signalling proteins known to be involved in the regulation of nitrogen metabolism. A reduced ornithine, citrulline and arginine accumulation was observed in two Arabidopsis PII knock‐out mutants in response to resupply after N starvation. This difference could be explained by the regulation of a key enzyme of the arginine biosynthesis pathway, N‐acetyl glutamate kinase (NAGK) by PII. In vitro assays using purified recombinant proteins showed the catalytic activation of Arabidopsis NAGK by PII giving the first evidence of a physiological role of the PII protein in higher plants. Using Arabidopsis transcriptome microarray (CATMA) and RT‐PCR analyses, it was found that none of the genes involved in the arginine biosynthetic or catabolic pathways were differentially expressed in a PII knock‐out mutant background. In conclusion, the observed changes in metabolite levels can be explained by the reduced activation of NAGK by PII.
Localization of subunit C (Vma5p) in the yeast vacuolar ATPase by immuno electron microscopy
Authors: Zhang Zhenyu , Inoue Takao , Forgac Michael , Wilkens Stephan
Published: March 2006

Vacuolar ATPases (V1V0‐ATPases) function in proton translocation across lipid membranes of subcellular compartments. We have used antibody labeling and electron microscopy to define the position of subunit C in the vacuolar ATPase from yeast. The data show that subunit C is binding at the interface of the ATPase and proton channel, opposite from another stalk density previously identified as subunit H [Wilkens S., Inoue T., and Forgac M. (2004) Three‐dimensional structure of the vacuolar ATPase – Localization of subunit H by difference imaging and chemical cross‐linking. J. Biol. Chem. 279, 41942–41949]. A picture of the vacuolar ATPase stalk domain is emerging in which subunits C and H are positioned to play a role in reversible enzyme dissociation and activity silencing.
PsbS enhances nonphotochemical fluorescence quenching in the absence of zeaxanthin
Authors: Crouchman Sophie , Ruban Alexander , Horton Peter
Published: March 2006

Leaves and chloroplasts from Arabidopsis plants with increased amounts of PsbS protein showed the same percentage increase in nonphotochemical quenching in comparison to the wild type both in the presence and absence of zeaxanthin. The absorption change at 525–535 nm was also more pronounced in both cases. It is suggested that PsbS alone can cause the quenching, supporting the model in which zeaxanthin acts as an allosteric activator and is not the primary cause of the process. It is proposed that PsbS acts as a trigger of the conformational change that leads to the establishment of nonphotochemical quenching.
Glucokinase regulatory protein is associated with mitochondria in hepatocytes
Authors: Arden Catherine , Baltrusch Simone , Agius Loranne
Published: March 2006

The association of glucokinase with liver mitochondria has been reported [Danial et al. (2003) BAD and glucokinase reside in a mitochondrial complex that integrates glycolysis and apoptosis. Nature 424, 952–956]. We confirmed association of glucokinase immunoreactivity with rat liver mitochondria using Percoll gradient centrifugation and demonstrated its association with the 68 kDa regulatory protein (GKRP) but not with the binding protein phosphofructokinase‐2/fructose bisphosphatase‐2. Substrates and glucagon induced adaptive changes in the mitochondrial glucokinase/GKRP ratio suggesting a regulatory role for GKRP. Combined with previous observations that GKRP overexpression partially inhibits glycolysis [de la Iglesia et al. (2000) The role of the regulatory protein of glucokinase in the glucose sensory mechanism of the hepatocyte. J. Biol. Chem. 275, 10597–10603] these findings suggest that there may be distinct glycolytic pools of glucokinase.