bluuebunny/crossref_metadata_2025 huggingface dataset:
Desaturation of color by environment light in cataract eyes
Authors: Ikeda Mitsuo , Obama Tomoko
Published: February 2008

The visual perception of the cataract eyes is composed of three elements, color, brightness, and haze. The color element is related to the reduced transmittance of light at short wavelengths of crystalline lens, the brightness element to the reduced transmittance at entire region of wavelength, and the haze element to the opacity of the crystalline lens. Researchers pay attention to only the color and brightness elements when they discuss on the color perception by the cataract eyes. We will show in this article that the haze element is also related to the color perception. There exists always environment light in our living situation. Light comes to the eyes from every direction. When the light enters the cataract eye it is scattered by the opacity of the crystalline lens and overlaps on the retinal image of objects that the eye is looking at. The environment light is usually white in color, and it reduces the colorimetric purity of the objects. The color appearance of the objects desaturates. This purity change was confirmed colorimetrically by measuring colors of test patches with the cataract simulating goggles placed in front of the lens of a colorimeter. The desaturation was then confirmed psychophysically by subjects wearing the goggles, who matched two color patches with and without the goggles. The same experiment was done by a subject whose right eye was operated for the cataract and the left eye was before the operation. Desaturation of color was found, though the desaturation was not as strong as with the goggles. In another psychophysical experiment the subject did the heterochromatic brightness matching experiment by using his right eye and left eye, respectively, before and after operation. The results were interpreted that all the color patches presented were perceived as being less saturated by eyes having cataracts. The importance was pointed out that, when we do experiments on the color perception by elderly observers we should not neglect the effect of the environment light. © 2008 Wiley Periodicals, Inc. Col Res Appl, 33, 142–147, 2008
Aryltellurenyl Cation [RTe(CR′2)]+ Stabilized by an N‐Heterocyclic Carbene
Authors: Beckmann Jens , Finke Pamela , Heitz Stephan , Hesse Malte
Published: February 2008

The reaction of the (mixed‐valent) aryltellurenyl halidesRTeTeCl2R (1), RTeTeBr2R (2) and RTeI (3, R = 2,6‐Mes2C6H3) with 1,3,4,5‐tetramethylimidazol‐2‐ylidene (CR′2) provides cationic aryltellurenyl carbene complexes of the type [RTe(CR′2)]+ A– (4, A = RTeCl2; 5, A = RTeBr2; 6, A = I). The stabilization energy and natural charge distribution of the model cation [PhTe(CR′2)]+ as well as the related σ‐donor‐stabilized cations [PhTe(PMe3)]+, [I(CR′2)]+, [I(PMe3)]+ were investigated by DFT calculations and NBO analyses.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
An Efficient Approach for the Synthesis of N‐1 Substituted Hydantoins
Authors: Kumar Vinod , Kaushik M. P. , Mazumdar Avik
Published: February 2008

An efficient three‐step route for the synthesis of N‐1 alkyl/aryl‐substituted hydantoins was developed from inexpensive commercially available substrates. The reaction of amines with cyanogen bromide takes place to give monoalkyl/aryl cyanamides. This on treatment with methyl bromoacetate in the presence of sodium hydride in tetrahydrofuran affords methyl N‐cyano‐N‐alkyl/arylaminoacetate, which undergoes hydrolysis and cyclization in the presence of 50 % H2SO4 to afford N‐1 substituted hydantoins in very good‐to‐excellent yields. Wide varieties of final products having primary, secondary, tertiary, and aryl substituents at the N‐1 position were successfully synthesized by this method. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Crystallographic and Theoretical Evidence of Anion–π and Hydrogen‐Bonding Interactions in a Squaramide–Nitrate Salt
Authors: Rotger Carmen , Soberats Bartomeu , Quiñonero David , Frontera Antonio , Ballester Pablo , Benet‐Buchholz Jordi , Deyà Pere M. , Costa Antoni
Published: February 2008

Synthetic anionic receptors are fundamental to the understanding of the mechanism of recognition phenomena, which is the basis of many fundamental biological processes. Recognition studies and X‐ray crystallography techniques provide accurate information on the structure of the molecular complexes and the nature of the interactions involved. Here, we present the first example of a squaramide–nitrate salt. X‐ray crystallography and theoretical studies show the important roles of anion–π and hydrogen‐bonding interactions in the crystal packing of this compound in relation to those found in the free squaramide solid structure.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Synthetic Strategies for Oseltamivir Phosphate
Authors: Shibasaki Masakatsu , Kanai Motomu
Published: February 2008

We review here the synthetic strategies for oseltamivir phosphate, an important orally active anti‐influenza drug. The Roche synthesis utilized naturally occurring shikimic acid as a starting material. Introduction of the 1‐ethylpropyloxy (“3‐pentyloxy”) functionality by regioselective reduction of the acetal and iterative ring‐opening reactions with azide to introduce nitrogen functionalities were the key steps. Corey and Fukuyama's syntheses utilized catalytic asymmetricDiels–Alder reactions as the starting points, whereas Shibasaki and Kanai's synthesis began with an asymmetric aziridine‐opening reaction with TMSN3 catalyzed by a polymetallic gadolinium complex. These three syntheses demonstrate the power of asymmetric catalysis in pharmaceutical synthesis. Although Kann's synthesis required resolution to provide an enantiomerically pure intermediate, the properties of chiral iron–diene complexes were elegantly utilized. Yao and Fang's syntheses started from abundant natural chiral sources: L‐serine and D‐xylose, respectively. Specifically, Fang's study identified new analogues of oseltamivir with higher potency against several neuraminidases, including oseltamivir‐resistant mutants. Despite the relatively small molecular size, oseltamivir synthesis highlights an important frontier in organic synthesis.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Interactive manipulation of blood cells using a lens‐integrated liquid crystal display based optoelectronic tweezers system
Authors: Hwang Hyundoo , Choi Yong‐Je , Choi Wonjae , Kim Se‐Hwan , Jang Jin , Park Je‐Kyun
Published: February 2008

This paper reports a lens‐integrated liquid crystal display (LCD)‐based optoelectronic tweezers (OET) system for interactive manipulation of polystyrene microspheres and blood cells by optically induced dielectrophoretic force. When a dynamic image pattern is projected into a specific area of a photoconductive layer in an OET, virtual electrodes are generated by spatially resolved illumination of the photoconductive layer, resulting in dielectrophoresis of microparticles suspended in the liquid layer under nonuniform electric field. In this study, the simple‐structured OET system has been easily constructed with an OET device, an LCD and a condenser lens integrated in a conventional microscope. By using a condenser lens, both stronger dielectrophoretic forces and higher virtual electrode resolution than previously reported lens‐less LCD‐based OET platform are obtained. The effects of blurred LCD image and liquid chamber height on the performances of optoelectronic particle manipulation are investigated by measuring the bead velocities according to their sizes. An interactive control program for OET‐based microparticle manipulation is also developed by Flash language. The integrated system is successfully applied to the parallel and interactive manipulation of red and white blood cells. Due to its simple structures, cheap manufacturing costs, and high performances, this new LCD‐based OET platform may be a widely usable integrated system for optoelectronic manipulation of microparticles including living cells.
Cationic surfactants for micellar electrokinetic chromatography: 1. Characterization of selectivity using the linear solvation energy relationships model
Authors: Schnee Vincent P. , Palmer Christopher P.
Published: February 2008

MEKC and the linear solvation energy relationship (LSER) model have been applied to two series of cationic surfactants. The synthetic flexibility of the quaternary ammonium group is exploited to generate the two series, one consisting of linear substitutions and the other incorporating the ammonium into ring structures of varying size. The effects of the head group structure on the CMC, aggregation number, and electrophoretic properties of the surfactants were determined. These surfactants were also characterized with the LSER model, which allowed the contributions of five chemical factors to the interactions between solutes and the micelles to be evaluated. Trends were observed in the cohesivity and polarity of the linear surfactant series, with both increasing with the size of the head group. No trends in the LSER parameters were observed in the cyclic series, but the LSER results do show that the surfactants with cyclic head groups provide a significantly different solvation environment from the linear series. Additional trends were observed in the aggregation behavior and chromatographic properties of the surfactants. These included changes in the CMCs, aggregation numbers, EOF, and electrophoretic mobility of the micelles that correlate to changes in head group size.
Characterization of a cationic phosphonium surfactant for micellar electrokinetic chromatography: Using the linear solvation energy relationships model
Authors: Schnee Vincent P. , Palmer Christopher P.
Published: February 2008

A phosphonium surfactant is introduced as a pseudostationary phase for MEKC and its performance and selectivity are compared to that of an analogous ammonium surfactant. The linear solvation energy relationship model has been applied to the two cationic surfactants, allowing the contributions of five chemical factors to the interactions between solutes and the micelles to be evaluated. Differences in the pseudophases cohesivity and acid/base interactions were observed. Despite the significant differences observed in the solvation parameter results the two phases have remarkably similar electrophoretic properties, with the anodic EOF produced by the dynamic coating and the electrophoretic mobility of the two surfactants being statistically equal.
Probabilistic impedance of foundation: Impact of the seismic design on uncertain soils
Authors: Cottereau Régis , Clouteau Didier , Soize Christian
Published: February 2008

In the linear seismic design of buildings, the (deterministic) substructure method is a customary and efficient approach. However, the existence of spatial variability in the parameters of the mechanical model of the soil, as well as parametric errors, calls for the use of probabilistic approaches in order to provide a reliable design of the structure. The construction of probabilistic models of the soil impedance matrix provides a natural path to such approaches within the context of the substructure method. Two main techniques are described in this paper: a parametric one, typically using the stochastic finite element method, and a nonparametric one, which was introduced more recently. The latter is explored more specifically, and the possibilities it offers in terms of seismic design are presented. In particular, it is shown that it allows for the estimation of quantiles of the quantities of interest, rather than confidence intervals, which lead to highly conservative design. Copyright © 2008 John Wiley & Sons, Ltd.
The morphological distinctiveness of Homo sapiens and its recognition in the fossil record: Clarifying the problem
Authors: Tattersall Ian , Schwartz Jeffrey H.
Published: February 2008

Species are historically differentiated entities that, osteologically, may be differentiated to inconveniently varying extents. Living Homo sapiens is a distinctive morphological entity that is easily distinguished in both cranial and postcranial morphology from all other living hominoids and from the vast majority of its fossil relatives. In this contribution, we offer several apparent cranial apomorphies of the living species, while recognizing that it is reasonable to expect some degree of overlap in the ranges of variation of individual characters among closely related species such as those within the genus Homo. No one aspect of morphological detail may be considered totally diagnostic within very close‐knit groups of this sort or, conversely, be regarded as blurring the identities of their components. Overlap in morphological detail may even be expected in cases where striking Gestalt differences exist between closely related species due to major developmental reorganization. As a result, while the morphological and, by extension, historical distinction between such highly differentiated species pairs as Homo neanderthalensis and Homo sapiens is effectively unequivocal, in a nod to the intrinsic untidiness of biology the hominid fossil record does offer some instances that are much more difficult to interpret. In such cases, most, but not all, of the cranial apomorphies of living Homo sapiens, are present in individual fossil specimens or apparent populations. This is true, for example, of a set of variably dated and archeologically associated, as well as mostly incomplete, South African fossils (for example, Border Cave, Boskop, Fish Hoek, and most Klasies River Mouth specimens). These specimens very closely resemble living Homo sapiens in preserved overall cranial structure, but most conspicuously lack bipartite brows and fully developed human chin configurations. Whatever resolutions hominid systematists may reach in such cases, it is clear that to resort reflexively to such pernicious if convenient devices as “archaic Homo sapiens” only obscures any potential signals of systematic diversity in what is increasingly evidently a highly complex late Pleistocene hominid record.
Speculations about the selective basis for modern human craniofacial form
Authors: Lieberman Daniel E.
Published: February 2008

The last few decades have seen an explosion of knowledge about the time and place of origin of our species, Homo sapiens. New fossils, more sites, better dates, modern and fossil DNA, and scores of analyses have mostly disproved the multiregional model of human evolution. By and large, the evidence generally supports some version of the out‐of‐Africa model, according to which humans first evolved in Africa at least 200,000 years ago and then migrated to other parts of the world. Remaining debates about human origins primarily address if and how much hybridization occurred between modern humans and taxa of archaic Homo such as H. neanderthalensis.
One‐Pot Four‐Component Synthesis of Tetrasubstituted Pyrroles
Authors: Kassaee M. Z. , Masrouri Hassan , Movahedi Farnaz , Partovi Tayyebeh
Published: February 2008

A convenient one‐pot four‐component synthesis of tetrasubstituted pyrroles was carried out through the reaction of butane‐2,3‐dione with α‐aminophosphorous ylides, obtained in situ from the 1 : 1 : 1 addition reaction between triphenylphosphine, dialkyl acetylenedicarboxylate, and ammonium acetate.
A Biomimetic Synthesis of Sacculatane Diterpenoids
Authors: Grinco Marina , Kulciţki Veaceslav , Ungur Nicon , Vlad Pavel F. , Gavagnin Margherita , Castelluccio Francesco , Cimino Guido
Published: February 2008

The biomimetic synthesis of sacculatane‐type epimeric compounds 14a and 14b is reported. The key synthetic step is the low‐temperature superacidic cyclization of (all‐E)‐ω‐acetoxygeranylgeraniol 12 obtained in nine steps from geranyllinalool (13). The 19‐acetoxysacculata‐7,17‐dien‐11‐ol (14a) could be an important and convenient starting compound for the synthesis of other sacculatane diterpenoids.
Copper‐Free Sonogashira Coupling of Acid Chlorides with Terminal Alkynes in the Presence of a Reusable Palladium Catalyst: An Improved Synthesis of 3‐Iodochromenones (=3‐Iodo‐4H‐1‐benzopyran‐4‐ones)
Authors: Likhar Pravin R. , Subhas M. S. , Roy Moumita , Roy Sarabindu , Kantam M. Lakshmi
Published: February 2008

Pd/C is used as an efficient catalyst for the copper‐free Sonogashira coupling of acid chlorides and terminal alkynes to afford ynones in high yields (Tables 1 and 3). Cyclization of (2‐methoxyaryl)‐substituted ynones induced by I2/ammonium cerium(IV) nitrate (CAN) at room temperature gave 3‐iodochromenones (=3‐iodo‐4H‐1‐benzopyran‐4‐ones) in excellent yield (Table 4).
New Approaches to the Synthesis of 4‐(2‐Aminophenyl)‐1,3‐dihydro‐2H‐imidazol‐2‐ones and 3‐Ureidoindoles and a Study of Their Interconversion
Authors: Klásek Antonín , Lyčka Antonín , Holčapek Michal , Hoza Ignác
Published: February 2008

3‐Alkyl/aryl‐3‐ureido‐1H,3H‐quinoline‐2,4‐diones (2) and 3a‐alkyl/aryl‐9b‐hydroxy‐3,3a,5,9b‐tetrahydro‐1H‐imidazo[4,5‐c]quinoline‐2,4‐diones (3) react in boiling concentrated HCl to give 5‐alkyl/aryl‐4‐(2‐aminophenyl)‐1,3‐dihydro‐2H‐imidazol‐2‐ones (6). The same compounds were prepared by the same procedure from 2‐alkyl/aryl‐3‐ureido‐1H‐indoles (4), which were obtained from the reaction of 3‐alkyl/aryl‐3‐aminoquinoline‐2,4(1H,3H)‐diones (1) with 1,3‐diphenylurea or by the transformation of 3a‐alkyl/aryl‐9b‐hydroxy‐3,3a,5,9b‐tetrahydro‐1H‐imidazo[4,5‐c]quinoline‐2,4‐diones (3) and 5‐alkyl/aryl‐4‐(2‐aminophenyl)‐1,3‐dihydro‐2H‐imidazol‐2‐ones (6) in boiling AcOH. The latter were converted into 1,3‐bis[2‐(2‐oxo‐2,3‐dihydro‐1H‐imidazol‐4‐yl)phenyl]ureas (5) by treatment with triphosgene. All compounds were characterized by 1H‐ and 13C‐NMR and IR spectroscopy, as well as atmospheric pressure chemical‐ionisation mass spectra.
Stereoselective Total Synthesis of Natural (S)‐Bakuchiol and Its Enantiomer
Authors: Du Xiao‐Long , Chen Hong‐Li , Feng Hui‐Jin , Li Yuan‐Chao
Published: February 2008

A practical stereoselective synthesis of (S)‐bakuchiol (1) and its enantiomer is reported. The important intermediate, (R)‐configured β‐siloxy aldehyde 5, was obtained in three steps from the easily available material geraniol (2) via the key step of Yamamoto's rearrangement of epoxy silyl ethers. (S)‐Bakuchiol (1) and its enantiomer, (R)‐bakuchiol (17), were finally obtained in different synthetic sequences with overall yields of 51% (ten steps) and 40% (nine steps) from geraniol (2), respectively.
Vitamin C suppresses proliferation of the human melanoma cell SK‐MEL‐2 through the inhibition of cyclooxygenase‐2 (COX‐2) expression and the modulation of insulin‐like growth factor II (IGF‐II) production
Authors: Lee Seung Koo , Kang Jae Seung , Jung Da Jung , Hur Dae Young , Kim Jee Eun , Hahm Eunsil , Bae Seyeon , Kim Hyung Woo , Kim Daejin , Cho Byung Joo , Cho Daeho , Shin Dong Hoon , Hwang Young‐Il , Lee Wang Jae
Published: February 2008

Vitamin C plays a crucial role in the suppression of proliferation of several types of cancer. Over‐expression of cyclooxygenase (COX)‐2 and type I insulin‐like growth factor (IGF) receptor are important for proliferation and protection from apoptosis in malignancies. However, its specific mechanisms, especially the interaction between COX‐2 expression and IGF‐I axis mediated by vitamin C, remain yet to be clarified. Therefore, we investigated the effects of vitamin C on the proliferation of melanoma cells via the modulation of COX‐2 expression and IGF‐I axis. As a result, we found that 1.0 mM vitamin C inhibits the proliferation of SK‐MEL‐2 without induction of apoptosis. At that moment, IGF‐II production was decreased, followed by the inhibition of COX‐2 activity. IGF‐IR expression was also down‐regulated by vitamin C treatment. It coincided with the result from the inhibition of COX‐2 by NS‐398 and COX‐2 siRNA. In addition, the decreased IGF‐IR expression by vitamin C was restored by the treatment of recombinant prostaglandin E2. Finally, we determined whether the signal pathway would be involved in vitamin C‐induced IGF‐II and IGF‐IR down‐regulation. When the cells were exposed to SB203580, a specific inhibitor of p38 MAPK, COX‐2 expression was dramatically recovered. In addition, phosphorylated p38 MAPK was increased after vitamin C treatment. Taken together, vitamin C suppresses proliferation of the human melanoma cell line SK‐MEL2 via the down‐regulation of IGF‐II production and IGF‐IR expression, which is followed by the activation of p38 MAPK and the inhibition of COX‐2 expression. J. Cell. Physiol. 216: 180–188, 2008. © 2008 Wiley‐Liss, Inc.
Roles of insulin and transferrin in neural progenitor survival and proliferation
Authors: Erickson Rebecca I. , Paucar Andres A. , Jackson Robert L. , Visnyei Koppany , Kornblum Harley
Published: February 2008

Multipotent neural progenitor cells or neural stem cells (NSC) can be propagated in vitro from a variety of sources and have great potential for neural repair. Although it is well known that NSC divide in response to basic fibroblast growth factor (FGF‐2) and epidermal growth factor (EGF), cofactors necessary for survival and maintenance of a multipotent potential are still a matter of debate. In the current study, we examined the requirements for NSC proliferation and survival in vitro using the neurosphere culture system. Apotransferrin (TF), along with EGF and FGF‐2, was sufficient for the formation of primary neurospheres derived from embryonic rat cortices. The addition of low concentrations of insulin or insulin‐like growth factor‐1 (IGF‐1) enhanced neurosphere size and number and was necessary for continued passaging. Both insulin and IGF‐1 acted at low concentrations, suggesting that their effects were mediated by their cognate receptors, both of which were expressed by neurosphere cultures. Sphere‐forming progenitors survived for long periods in culture without EGF or FGF‐2 when either insulin or IGF‐1 was added to the media. Cell cycle analysis determined that surviving progenitors were relatively quiescent during the period without mitogens. Upon the reintroduction of EGF and FGF‐2, surviving progenitors gave rise to new spheres that produced largely glial‐restricted progeny compared with sister cultures. These data indicate that the neurogenic potential of NSC may be intimately linked to a continuous exposure to mitogens. © 2008 Wiley‐Liss, Inc.
Neuronal differentiation elicited by glial cell line‐derived neurotrophic factor and ciliary neurotrophic factor in adrenal chromaffin cell line tsAM5D immortalized with temperature‐sensitive SV40 T‐antigen
Authors: Murata Tomiyasu , Tsuboi Masaru , Koide Naoshi , Hikita Kiyomi , Kohno Susumu , Kaneda Norio
Published: February 2008

To understand the characteristics of tsAM5D cells immortalized with the temperature‐sensitive simian virus 40 large T‐antigen, we first examined the responsiveness of the cells to ligands of the glial cell line‐derived neurotrophic factor (GDNF) family. tsAM5D cells proliferated at the permissive temperature of 33°C in response to either GDNF or neurturin, but not persephin or artemin. At the nonpermissive temperature of 39°C, GDNF or neurturin caused tsAM5D cells to differentiate into neuron‐like cells; however, the differentiated cells died in a time‐dependent manner. Interestingly, ciliary neurotrophic factor (CNTF) did not affect the GDNF‐mediated cell proliferation at 33°C but promoted the survival and differentiation of GDNF‐treated cells at 39°C. In the presence of GDNF plus CNTF, the morphological change induced by the temperature shift was associated with up‐regulated expression of various neuronal marker genes, indicating that the cells had undergone neuronal differentiation. In addition, tsAM5D cells caused to differentiate by GDNF plus CNTF at 39°C became dependent solely on nerve growth factor (NGF) for their survival and neurite outgrowth. Moreover, upon treatment with GDNF plus CNTF, the dopaminergic phenotype was suppressed by the temperature shift. Thus, we demonstrated that tsAM5D cells had the capacity to differentiate terminally into neuron‐like cells in response to GDNF plus CNTF when the oncogene was inactivated by the temperature shift. This cell line provides a useful model system for studying the role of a variety of signaling molecules for GDNF/CNTF‐induced neuronal differentiation. © 2008 Wiley‐Liss, Inc.
Calcium‐dependent production of reactive oxygen species is involved in neuronal damage induced during glycolysis inhibition in cultured hippocampal neurons
Authors: Hernández‐Fonseca Karla , Cárdenas‐Rodríguez Noemí , Pedraza‐Chaverri José , Massieu Lourdes
Published: February 2008

Neuronal damage associated with in vivo hypoglycemia has been suggested to be excitotoxic due to the release of excitatory amino acids and the protective effect of glutamate receptor antagonists. The production of reactive oxygen species (ROS) has been also implicated in hypoglycemic damage. Excitotoxicity involves oxidative stress, insofar as the influx of calcium through N‐methyl‐D‐aspartate (NMDA) receptors stimulates ROS production. We have studied the participation of NMDA receptors and intracellular calcium in ROS production and cell death triggered during moderate and severe glycolysis inhibition in cultured hippocampal neurons. Iodoacetate (IOA), an inhibitor of the glycolytic enzyme glyceraldehyde‐3‐phosphate dehydrogenase (GAPDH), dose dependently reduces ATP levels and cell survival and increases the intracellular concentration of calcium. During mild glycolysis inhibition, the increases in intracellular calcium, ROS production, and cell death are dependent on NMDA receptor activation. In contrast, during severe glycolysis impairment, these processes are not inhibited by NMDA receptor blockade. BAPTA‐AM and vitamin E efficiently reduce ROS generation and cell death under both conditions. Results suggest that calcium influx through NMDA receptors is involved in ROS production and neuronal damage resulting from moderate energy depletion, whereas intracellular calcium increase and ROS generation during severe glycolysis inhibition are more related to energy depletion. © 2008 Wiley‐Liss, Inc.
Epigenetic modifications of SOX2 enhancers, SRR1 and SRR2, correlate with in vitro neural differentiation
Authors: Sikorska Marianna , Sandhu Jagdeep K. , Deb‐Rinker Paromita , Jezierski Anna , LeBlanc Julie , Charlebois Claudie , Ribecco‐Lutkiewicz Maria , Bani‐Yaghoub Mahmud , Walker P. Roy
Published: February 2008

SOX2 is a key neurodevelopmental gene involved in maintaining the pluripotency of stem cells and proliferation of neural progenitors and astroglia. Two evolutionally conserved enhancers, SRR1 and SRR2, are involved in controlling SOX2 expression during neurodevelopment; however, the molecular mechanisms regulating their activity are not known. We have examined DNA methylation and histone H3 acetylation at both enhancers in NT2‐D1 progenitors, neurons and astrocytes, to establish the role of epigenetic mechanisms in cell‐type‐specific SOX2 expression. This study showed that 1) unmethylated DNA and acetylated histones at both enhancers correlated with a high level of SOX2 expression in proliferating neural progenitors and 2) reversible modifications of the SRR1 element were observed during gene reexpression in astrocytes, whereas permanent epigenetic marks on the SRR2 enhancer were seen in neurons where the gene was silenced. Taken together, these results are clear illustrations of cell‐type‐specific epigenomes and suggest mechanisms by which they may be created and maintained. © 2008 Wiley‐Liss, Inc.
Sustained striatal ciliary neurotrophic factor expression negatively affects behavior and gene expression in normal and R6/1 mice
Authors: Denovan‐Wright Eileen M. , Attis Marissa , Rodriguez‐Lebron Edgardo , Mandel Ronald J.
Published: February 2008

Huntington's disease (HD) is a neurodegenerative disorder caused by an elongation of CAG repeats in the HD gene, which encodes a mutant copy of huntingtin with an expanded polyglutatmine repeat. Individuals who are affected by the disease suffer from motor, cognitive, and emotional impairments. Levels of certain striatal‐enriched mRNAs decrease in both HD patients and transgenic HD mice prior to the development of motor symptoms and neuronal cell death. Ciliary neurotrophic factor (CNTF) has been shown to protect neurons against chemically induced toxic insults in vitro and in vivo. To test the hypothesis that CNTF might protect neurons from the negative effects of the mutant huntingtin protein in vivo, CNTF was continuously expressed following transduction of the striatum by recombinant adeno‐associated viral vectors (rAAV2). Wild‐type and R6/1 HD transgenic (R6/1) mice that received bilateral or unilateral intrastriatal injections of rAAV2‐CNTF experienced weight loss. The CNTF‐treated R6/1 HD transgenic mice experienced motor impairments at an earlier age than expected compared with age‐matched control R6/1 HD transgenic animals. CNTF also caused abnormal behavior in WT mice. In addition to behavioral impairments, in situ hybridization showed that, in both WT and R6/1 mice, CNTF expression caused a significant decrease in the levels of striatal‐enriched transcripts. Overall, continuous expression of striatal CNTF at the dose mediated by the expression cassette used in this study was detrimental to HD and wild‐type mice. © 2008 Wiley‐Liss, Inc.
Theanine, an ingredient of green tea, inhibits [3H]glutamine transport in neurons and astroglia in rat brain
Authors: Kakuda Takami , Hinoi Eiichi , Abe Akihiro , Nozawa Ayumu , Ogura Masato , Yoneda Yukio
Published: February 2008

We have previously shown that theanine (=γ‐glutamylethylamide), an ingredient of green tea, has a protective effect against ischemic neuronal death in the hippocampal CA1 region of the gerbil brain without affecting ligand binding to ionotropic receptor subtypes of the neurotransmitter glutamate structurally related to theanine. The neurotransmitter pool of glutamate is thought to be fueled by the entry of the other structural analog glutamine (Gln) and subsequent cleavage by glutaminase. Although theanine did not inhibit [3H]glutamate accumulation, [3H]theanine was actively accumulated in a temperature‐dependent and saturable manner in rat brain synaptosomal fractions. The accumulation of [3H]theanine was markedly inhibited by Gln in a concentration‐dependent manner, whereas [3H]Gln accumulation was inhibited by theanine vice versa. Both [3H]theanine and [3H]Gln accumulations were decreased after the replacement of sodium chloride with choline chloride, along with similarly high distribution profiles in telencephalic structures. A similar equilibrium was observed within 30 min at 30°C for the accumulations of both [3H]theanine and [3H]Gln in cultured rat neocortical astroglia as well as neurons, whereas theanine inhibited [3H]Gln accumulation in a concentration‐dependent manner at 0.1–10 mM. Furthermore, sustained exposure to 10 mM theanine led to a significant decrease in the level of extracellular glutamate released from cultured neurons. These results suggest that the green tea ingredient theanine would be an inhibitor of different transporters capable of transporting Gln across plasma membranes toward the modulation of the glutamate/Gln cycle required for the neurotransmitter pool of glutamate in neurons. © 2008 Wiley‐Liss, Inc.
Workplace offense and victims' reactions: the effects of victim‐offender (dis)similarity, offense‐type, and cultural differences
Authors: Kim Tae‐Yeol , Shapiro Debra L. , Aquino Karl , Lim Vivien K. G. , Bennett Rebecca J.
Published: February 2008

This study examined the effects of workplace offenders' characteristics and offense‐type on victims' reactions. Responses from 352 employed graduate students in the U.S. and South Korea to a hypothetical offense incident revealed that employees from the U.S. and Korea differ in their expressed desirability of avoiding, seeking revenge against, and reconciling with an offending coworker depending on the offenders' similarity/dissimilarity to the victim and on the type of offense. As expected, Koreans (but not U.S. Americans) were more likely to avoid and to seek revenge on a coworker whose offensive remark was group‐ rather than personally‐directed. In addition, Koreans were most motivated to reconcile when an offensive remark came from a similar rather than dissimilar coworker and when the offense targeted them personally (not their group). However, U.S. Americans were most motivated to reconcile when an offensive remark came from a similar rather than dissimilar other and when the offense targeted their group (not them personally). Copyright © 2008 John Wiley & Sons, Ltd.
Seasonal probability of precipitation forecasts using a weighted ensemble approach
Authors: Shin D. W. , Kang S.‐D. , Cocke S. , Goo T.‐Y. , Kim H.‐D.
Published: February 2008

A weighted ensemble (WE) method is revisited and employed to issue an improved seasonal probability of precipitation (POP) forecast. Nine boreal summer time seasonal precipitation hindcasts obtained from the APEC (Asia‐Pacific Economic Cooperation) Climate Center (APCC) multi‐model ensemble system are used to assess the suitability of the WE approach for seasonal POP predictions. Owing to its performance‐based selective nature for assigning weights, the WE method produced marginally superior seasonal POP forecasts compared to the conventional approach. Copyright © 2008 Royal Meteorological Society
Ionic liquid structure: the conformational isomerism in 1‐butyl‐3‐methyl‐imidazolium tetrafluoroborate ([bmim][BF4])
Authors: Holomb R. , Martinelli A. , Albinsson I. , Lassègues J. C. , Johansson P. , Jacobsson P.
Published: February 2008

As a probe of local structure, the vibrational properties of the 1‐butyl‐3‐methylimidazolium tetrafluoroborate [bmim][BF4] ionic liquid were studied by infrared (IR), Raman spectroscopy, and ab initio calculations. The coexistence of at least four [bmim]+ conformers (GG, GA, TA, and AA) at room temperature was established through unique spectral responses. The Raman modes characteristic of the two most stable [bmim]+ conformers, GA and AA, according to the ab initio calculations, increase in intensity with decreasing temperature. To assess the total spectral behavior of the ionic liquid both the contributions of different [bmim]+ conformers and the [bmim]+− [BF4]− interactions to the vibrational spectra are discussed. Copyright © 2008 John Wiley & Sons, Ltd.
Prognostic significance of expression of CCL5/RANTES receptors in patients with gastric cancer
Authors: Sugasawa Hidekazu , Ichikura Takashi , Tsujimoto Hironori , Kinoshita Manabu , Morita Daisaku , Ono Satoshi , Chochi Kentaro , Tsuda Hitoshi , Seki Shuhji , Mochizuki Hidetaka
Published: February 2008

Background and Objectives

The clinical significance of CCL5 has been reported in several malignancies. In this study, we examined the prognostic impact of serum CCL5 levels and the expression of CCL5 receptors on tumor cells in patients with gastric cancer.

Methods

Serum CCL5 levels in patients with gastric cancer were measured by enzyme‐linked immunoabsorbent assay. Immunohistochemical staining of three chemokine receptors, CCR1, CCR3, and CCR5, which are known as CCL5 receptors, was performed in gastric cancer tissue.

Results

We found that serum CCL5 levels themselves had no impact on survival; however, higher serum CCL5 concentrations were associated with more advanced disease. Eighty‐six (41%), 48 (23%), and 60 patients (28%) showed positive expression of CCR1, CCR3, and CCR5, respectively, on gastric cancer cells. Among the patients who underwent curative resection for stages II–IV disease, patients with positive CCR3 expression had significantly lower survival rates compared to those with negative CCR3 expression. Unlike CCR1, positive CCR5 expression was also associated with poorer prognosis. Multivariate analysis revealed that expression of CCR3 and/or CCR5 was an independent prognostic factor.

Conclusions

Tumor expression of CCR3 and/or CCR5 (receptors for CCL5) is associated with a lower survival rate in patients with gastric cancer. J. Surg. Oncol. 2008;97:445–450. © 2008 Wiley‐Liss, Inc.
Nuclear localization of annexin A1 is a prognostic factor in oral squamous cell carcinoma
Authors: Lin Chiao‐Ying , Jeng Yung‐Ming , Chou Han‐Yi , Hsu Hey‐Chi , Yuan Ray‐Hwang , Chiang Chun‐Pin , Kuo Mark Yen‐Ping
Published: February 2008

Background and Objectives

To investigate whether annexin A1 (ANXA1) expression is a marker in predicting the prognosis of oral cancer patients.

Methods

We immunohistochemically examined the expression of ANXA1 in 66 cases of oral epithelial dysplasia (OED) and 115 cases of oral squamous cell carcinoma (OSCC). The results were correlated with the clinicopathological parameters of tumors and overall patient survival.

Results

In normal oral mucosa, ANXA1 staining was predominantly located on the cell membrane. In OED and OSCC specimens, membranous staining decreased, whereas nuclear staining increased. Positive nuclear staining was observed in 9 of 66 (13.64%) OED cases and 63 of 115 (54.8%) OSCCs. Kaplan–Meier curves showed that OSCC patients with ANXA1 nuclear staining had significantly shorter overall lengths of survival (P = 0.00036 by the log‐rank test). Multivariate analysis showed that ANXA1 nuclear staining is a significant predictor of poor overall survival. And oral cancer SAS cells treated with hepatocyte growth factor (HGF) can induce ANXA1 protein translocation from cytoplasm to nucleus. Cells pretreated with LY294002 (PI3K inhibitor) almost completely inhibited (88.3% inhibition) HGF‐mediated ANXA1 nuclear translocation.

Conclusions

The nuclear localization of ANXA1 protein is a frequent event and could be used as a prognostic factor in OSCC. J. Surg. Oncol. 2008;97:544–550. © 2008 Wiley‐Liss, Inc.
On‐line concentration and pressurized capillary electrochromatographic analysis of phytohormones in corn
Authors: Wang Shujuan , Jia Li , Xing Da , Chen Deping , Zhao Jingshan
Published: February 2008

A pressurized CEC (pCEC) method was developed for the separation of phytohormones, in which UV absorbance was used as the detector and a monolithic silica‐ODS column as the separation column. The parameters (including the concentration of organic solvent in the mobile phase, pH of the electrolyte buffer, applied voltage) affecting the separation resolution were evaluated. Two on‐line concentration techniques, namely, solvent gradient zone sharpening effect and field‐enhanced sample stacking, were utilized to improve detection sensitivity. The combination of the two techniques proved to be beneficial to enhance the detection sensitivity by enabling the injection of large volumes of samples. Compared to the conventional injection mode, the enhancement in the detection sensitivities of phytohormones using the on‐line concentration technique is in the range from 9‐ to 23‐fold. The developed pCEC method was applied to evaluate phytohormones in corns.
Simultaneous determination of seven flavonoids in Epimedium using pressurized liquid extraction and capillary electrochromatography
Authors: Chen Xiao‐jia , Ji Hui , Wang Yi‐tao , Li Shao‐ping
Published: February 2008

Herba Epimedii (known as Yinyanghuo in China) is one of the commonly used Chinese medicines. Flavonoids are considered as its active components. In this study, a CEC method was developed for the simultaneous determination of seven flavonoids, including hexandraside E, kaempferol‐3‐O‐rhamnoside, hexandraside F, icariin, epimedin A, B, and C, in Epimedium using baicalein as internal standard (IS). The influence of relevant parameters such as buffer concentration, pH, and proportion of ACN was investigated and optimized. Baseline separation was obtained using a Hypersil C18 capillary (3 μm, 100 μm/25 cm) with a mixture of 20 mM phosphate buffer (pH 4.0)/ACN (70:30 v/v) as mobile phase running at 30 kV and 25°C in 20 min. All calibration curves showed good linearity (r2 >0.9992) within test ranges. The LOD and LOQ were lower than 8.6 and 42.8 μg/mL, respectively. The RSDs of intra‐ and interday for relative peak areas of seven analytes were less than 3.1 and 4.4%, and the recoveries were 95.2–103.3%. Samples of different Epimedium species were analyzed using the validated method, which is useful for quality control of Epimedium and its medical preparations.
Below the tip of the iceberg: the co‐evolution of formal and informal interorganizational relations in the wireless telecommunications industry
Authors: Rosenkopf Lori , Schleicher Thomas
Published: February 2008

We examine how alliances—formal, contractual interorganizational relations—co‐evolve with emergent, informal interorganizational relations. To form alliances, firms must acquire information on potential partners, and the acquisition of this intelligence occurs through both formal and informal channels. Here we evaluate the effects of two of these informal channels: joint participation in cooperative technical organizations (CTOs) and director interlocks. Since director interlocks connect firms through the highest managerial levels while joint CTO participation connects firms through mid‐level technical personnel, we examine whether each type of informal tie contributes to alliance formation as well as whether ties at multiple levels serve as complements or substitutes for this purpose. We also examine whether all types of ties—alliances, interlocks and CTO participation—co‐evolve endogenously or whether there are more direct causal relationships between and among these various types of networks. We find that both interlocks and CTO participation facilitate alliance formation, yet interlocks only facilitate alliance formation when the common director serves as an officer in one of the firms. An additional distinction between the role of interlocks and CTO participation is that the relationship between interlocks and alliance formation appears endogenous, in contrast to CTO participation, which causally precedes alliance formation. Copyright © 2008 John Wiley & Sons, Ltd.
Dynamic server assignment policies for assembly‐type queues with flexible servers
Authors: Tsai Yi‐Chun , Argon Nilay Tanık
Published: February 2008

We seek dynamic server assignment policies in finite‐capacity queueing systems with flexible and collaborative servers, which involve an assembly and/or a disassembly operation. The objective is to maximize the steady‐state throughput. We completely characterize the optimal policy for a Markovian system with two servers, two feeder stations, and instantaneous assembly and disassembly operations. This optimal policy allocates one server per station unless one of the stations is blocked, in which case both servers work at the unblocked station. For Markovian systems with three stations and instantaneous assembly and/or disassembly operations, we consider similar policies that move a server away from his/her “primary” station only when that station is blocked or starving. We determine the optimal assignment of each server whose primary station is blocked or starving in systems with three stations and zero buffers, by formulating the problem as a Markov decision process. Using this optimal assignment, we develop heuristic policies for systems with three or more stations and positive buffers, and show by means of a numerical study that these policies provide near‐optimal throughput. Furthermore, our numerical study shows that these policies developed for assembly‐type systems also work well in tandem systems. © 2008 Wiley Periodicals, Inc. Naval Research Logistics, 2008
Development of an instrument to assess perceived self‐efficacy in the parents of infants
Authors: Črnčec Rudi , Barnett Bryanne , Matthey Stephen
Published: February 2008

In addition to research applications, the measurement of perceived parental self‐efficacy (PPSE) could be useful clinically in screening for parenting difficulties, targeting interventions, and evaluating outcomes. In this research we examined the psychometric properties of the Karitane Parenting Confidence Scale (KPCS), a new 15‐item PPSE measure. A no‐problem control group and three clinical groups comprising 187 mothers with infants were recruited. The KPCS showed acceptable internal consistency (Cronbach's alpha = .81), test–retest reliability (r = .88), and discriminant and convergent validity. A cut‐off score was determined, and the scale's sensitivity and positive predictive power was 86% and 88%, respectively. The KPCS may prove a useful addition to tools for the assessment of parents and infants presenting to clinical services. © 2008 Wiley Periodicals, Inc. Res Nurs Health 31:442–453, 2008
Proteomics, networks and connectivity indices
Authors: González‐Díaz Humberto , González‐Díaz Yenny , Santana Lourdes , Ubeira Florencio M. , Uriarte Eugenio
Published: February 2008

Describing the connectivity of chemical and/or biological systems using networks is a straight gate for the introduction of mathematical tools in proteomics. Networks, in some cases even very large ones, are simple objects that are composed at least by nodes and edges. The nodes represent the parts of the system and the edges geometric and/or functional relationships between parts. In proteomics, amino acids, proteins, electrophoresis spots, polypeptidic fragments, or more complex objects can play the role of nodes. All of these networks can be numerically described using the so‐called Connectivity Indices (CIs). The transformation of graphs (a picture) into CIs (numbers) facilitates the manipulation of information and the search for structure‐function relationships in Proteomics. In this work, we review and comment on the challenges and new trends in the definition and applications of CIs in Proteomics. Emphasis is placed on 1‐D‐CIs for DNA and protein sequences, 2‐D‐CIs for RNA secondary structures, 3‐D‐topographic indices (TPGIs) for protein function annotation without alignment, 2‐D‐CIs and 3‐D‐TPGIs for the study of drug‐protein or drug‐RNA quantitative structure‐binding relationships, and pseudo 3‐D‐CIs for protein surface molecular recognition. We also focus on CIs to describe Protein Interaction Networks or RNA co‐expression networks. 2‐D‐CIs for patient blood proteome 2‐DE maps or mass spectra are also covered.
Proteomic approaches to the analysis of multiprotein signaling complexes
Authors: Yang Wei , Steen Hanno , Freeman Michael R.
Published: February 2008

Signal transduction is one of the most active fields in modern biomedical research. Increasing evidence has shown that signaling proteins associate with each other in characteristic ways to form large signaling complexes. These diverse structures operate to boost signaling efficiency, ensure specificity and increase sensitivity of the biochemical circuitry. Traditional methods of protein analysis are inadequate to fully characterize and understand these structures, which are intricate, contain many components and are highly dynamic. Instead, proteomics technologies are currently being applied to investigate the nature and composition of multimeric signaling complexes. This review presents commonly used and potential proteomic methods of analyzing diverse protein complexes along with a discussion and a brief evaluation of alternative approaches. Challenges associated with proteomic analysis of signaling complexes are also discussed.
Proteomics, nanotechnology and molecular diagnostics
Authors: Johnson Christopher J. , Zhukovsky Nikolay , Cass Anthony E. G. , Nagy Judit M.
Published: February 2008

Sequencing of the human genome opened the way to the exploration of the proteome and this has lead to the identification of large numbers of proteins in complex biological samples. The identification of diagnostic patterns in samples taken from patients to aid diagnosis is in the early stages of development. The solution to many of the technical challenges in proteomics and protein based molecular diagnostics will be found in new applications of nanomaterials. This review describes some of the physical and chemical principles underlying nanomaterials and devices and outlines how they can be used in proteomics; developments which are establishing nanoproteomics as a new field. Nanoproteomics will provide the platform for the discovery of next generation biomarkers. The field of molecular diagnostics will then come of age.