bluuebunny/crossref_metadata_2025 huggingface dataset:
α‐Haloalkylboronates
Authors: Matteson D. S.
Published: May 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Sulfanyl‐ and Selanylboranes
Authors: Habben C. , Kaufmann D. E.
Published: May 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Microwave‐Supported Organic Synthesis: Applications. Part 36. Fused Heterocycles
Authors: Keller Walter E.
Published: May 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Surface Thermodynamics Revisited
Authors: Rusanov A. I.
Published: May 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Thermochemistry of Organic and Heteroorganic Species. Part 13. Structural Aspects and Thermochemical Approach to Isomerization and Fragmentation of Negative Ions. Simple Bond Cleavage and Hydrogen Rearrangement Processes
Authors: Ponomarev Dmitry , Takhistov Viatcheslav
Published: May 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Computational Studies of the Primary Phototransduction Event in Visual Rhodopsin
Authors: Gascon Jose A. , Sproviero Eduardo M. , Batista Victor S.
Published: May 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Artificial Molecular Motors Powered by Light
Authors: Credi Alberto
Published: May 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Dynamical Structure of Peptide Molecules
Authors: Kawashima Yoshiyuki , Usami Tsuyoshi , Ohashi Nobukimi , Suenram Richard D. , Hougen Jon T. , Hirota Eizi
Published: May 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Chemotopic representations of aromatic odorants in the rat olfactory bulb
Authors: Farahbod Haleh , Johnson Brett A. , Minami S. Sakura , Leon Michael
Published: May 2006

Our laboratory has characterized spatial patterns of evoked neural activity across the entire glomerular layer of the rat olfactory bulb using primarily aliphatic odorants that differ systematically in functional groups and hydrocarbon structures. To represent more fully the true range of odorant chemistry, we investigated aromatic compounds, which have a more rigid molecular structure than most aliphatic compounds and are particularly salient olfactory stimuli for humans. We first investigated glomerular patterns of 2‐deoxyglucose uptake in response to aromatic compounds that differ in the nature and position of their functional groups (e.g., xylenes, trimethylbenzenes, tolualdehydes, benzaldehydes, methyl toluates, and anisaldehydes). We also studied the effects of systematic increases in the number and length of alkyl substituents. We found that most aromatic compounds activated glomeruli in the dorsal part of the bulb. Within this general area, aromatic odorants with oxygen‐containing substituents favored activation of more rostral regions, and aromatic hydrocarbons activated more posterior regions. The nature of substituents greatly affected the pattern of glomerular activation, whereas isomers differing in substitution position evoked very similar overall patterns. These relationships between the structure of aromatic compounds and their spatial representation in the bulb are contrasted with our previous findings with aliphatic odorants. J. Comp. Neurol. 497:350–366, 2006. © 2006 Wiley‐Liss, Inc.
Thalamocortical connections of anterior and posterior parietal cortical areas in New World titi monkeys
Authors: Padberg Jeffrey , Krubitzer Leah
Published: May 2006

We examined the thalamocortical connections of electrophysiologically identified locations in the hand and forelimb representations in areas 3b, 1, and 5 in the New World titi monkeys (Callicebus moloch), and of area 7b/AIP. Labeled cells and terminals in the thalamus resulting from the injections were related to architectonic boundaries. As in previous studies in primates, the hand representation of area 3b has dense, restricted projections predominantly from the lateral division of the ventral posterior nucleus (VPl). Projections to area 1 were highly convergent from several thalamic nuclei including the ventral lateral nucleus (VL), anterior pulvinar (PA), VPl, and the superior division of the ventral posterior nucleus (VPs). In cortex immediately caudal to area 1, what we term area 5, thalamocortical connections were also highly convergent and predominantly from nuclei of the thalamus associated with motor, visual, or somatic processing such as VL, the medial pulvinar (PM), and PA, respectively; with moderate projections from VP, central lateral nucleus (CL), lateral posterior nucleus (LP), and VPs. Finally, thalamocortical connections of area 7b/AIP were from a range of nuclei including PA, PM, LP/LD, VL, CL, PL, and CM. The current data support two conclusions drawn from previous studies in titi monkeys and other primates. First, cortex caudal to area 1 in New World monkeys is more like area 5 than area 2. Second, the presence of thalamic input to area 5 from both motor nuclei and somatosensory nuclei of the thalamus, suggests that area 5 could be considered a highly specialized sensorimotor area. J. Comp. Neurol. 497:416–435, 2006. © 2006 Wiley‐Liss, Inc.
The adult neural stem and progenitor cell niche is altered in amyotrophic lateral sclerosis mouse brain
Authors: Liu Zhiping , Martin Lee J.
Published: May 2006

Amyotrophic lateral sclerosis (ALS) is a fatal adult human disease caused by motor neuron degeneration. Stem cell therapy might be a treatment for ALS. The adult mammalian forebrain has neural stem cells (NSCs) and neural progenitor cells (NPCs) in the anterior subventricular zone (SVZa), rostral migratory stream (RMS), olfactory bulb (OB) core, and dentate gyrus (DG). These cells could be used to rescue or replace degenerating upper and lower motor neurons through endogenous recruitment or autologous/allogenic transplantation. We evaluated the competency of forebrain NSCs and NPCs in transgenic (tg) mice harboring human mutant superoxide dismutase‐1 (mSOD1), a model of ALS. Tg human wild‐type SOD1 (wtSOD1) mice and non‐tg mice were controls. Bromodeoxyuridine (BrdU) labeling of cells, a marker for cell proliferation and other events, was reduced in a niche‐specific pattern in presymptomatic and symptomatic mice, with the SVZa having greater reductions than the RMS, OB, and DG. Different NSC and NPC complements were evaluated by localizing nestin, neural cell adhesion molecule, distalless‐2 transcription factor, vimentin, and glial fibrillary acidic protein. In symptomatic mice, NSC markers were reduced, whereas NPC markers were unchanged or elevated. Neurogenesis was preserved in symptomatic mSOD1 mice. NSC/NPC competence assessment in vitro revealed that mSOD1 SVZa cells had the ability to proliferate and form neurospheres but had an impaired response to mitogen stimulation. We conclude that adult mSOD1 ALS mice have abnormalities in forebrain NSCs, but the essential features of NSC/NPCs remained in presymptomatic and symptomatic mice. J. Comp. Neurol. 497:468–488, 2006. © 2006 Wiley‐Liss, Inc.
Cu2O Nanowires in an Alumina Template: Electrochemical Conditions for the Synthesis and Photoluminescence Characteristics
Authors: Ko Eunseong , Choi Jinsub , Okamoto Koichi , Tak Yongsug , Lee Jaeyoung
Published: May 2006

Cu2O nanowires, mainly consisting of (100) and (200) polycrystalline structures with a length of 4 μm are prepared by electrochemical deposition using a porous alumina template. It is found that the optimized electrochemical conditions to prepare Cu2O nanowires are different from those for the formation of a bulk thin Cu2O layer since different pH values are found between the tip of the pores and the bulk, due to diffusion limits in porous alumina with an extremely high aspect ratio of 300. We point out that Cu2O (200), Cu2O (111), Cu, and co‐deposited alloys can be obtained under specific electrochemical conditions. In addition, the optical band gap of the prepared Cu2O nanowires with a length of 4 μm and a diameter of 200 nm is estimated to be 2.17 eV from photoluminescence measurements.
Ana and the Internet: A review of pro‐anorexia websites
Authors: Norris Mark L. , Boydell Katherine M. , Pinhas Leora , Katzman Debra K.
Published: May 2006

Objective:

The purpose of this article is to describe the content of pro‐anorexia websites, both qualitatively and quantitatively.

Method:

An Internet search protocol was developed to identify pro‐anorexia websites. A grounded theory approach was used to generate themes from Internet‐based information. Basic descriptive analysis was employed to report on key website characteristics.

Results:

Twenty pro‐anorexia websites met inclusion criteria. Saturation of themes was achieved after review of 12 websites. Key website characteristics included purpose of website (75%), information about webmaster (67%), website disclaimers (58%), and information on “tips and tricks” (67%). Religious metaphors, lifestyle descriptions, and “thinspiration” (inspirational photo galleries and quotes that aim to serve as motivators for weight loss) were frequently present. A total of 10 themes were generated. The most prevalent themes included control, success, and perfection.

Conclusion:

Health‐care providers and caregivers should be aware of pro‐anorexia websites and their content, as these websites contain information that promote and support anorexia nervosa. © 2006 by Wiley Periodicals, Inc. Int J Eat Disord 2006
The Stereochemistry of Allenic Enol Tautomerism – Independent Generation and Reactivity of the Enolates
Authors: Zimmerman Howard E. , Pushechnikov Alexei
Published: May 2006

A priori, allenic enolates as reaction intermediates may be protonated to afford (Z)‐ or (E)‐α,β‐unsaturated carbonyl products. The allenic enolates are tautomeric with α‐vinylcarbanions. The literature on the behavior of these species on protonation is highly varied both in stereochemical outcome and in mechanistic interpretation. The current study has provided an independent mode of generation of the allenic enolates and has investigated the reaction stereochemistry of protonation to afford the stereoisomeric α,β‐unsaturated carbonyl products. Under kinetic conditions, these highly reactive species are protonated in the α,β‐π plane with preference (E) to the larger β group. Under thermodynamic conditions, addition/elimination equilibrates the two product stereoisomers. The kinetic protonation stereochemistry is a function of solvent, proton donor, and donor concentration. Computations serve to clarify the reaction mechanism. It was found that the stereochemistry of ketonization of allenic enolates follows the reaction course suggested as possible some decades earlier and common to less unique enolates. Additionally, the linear versus the bent enolate structure proves to depend on the countercation.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Actual, ideal, and expected relatedness with parents across and within cultures
Authors: Imamoğlu E. Olcay , Karakitapoğlu‐Aygün Zahide
Published: May 2006

Differences in actual, ideal, and expected relatedness with mothers and fathers were explored across two cultural groups (i.e., university students from the U.S. and Turkey) in Study 1, and across two socioeconomic status (SES) groups (i.e., high school students from the upper and lower SES in Turkey) in Study 2. In both studies associations of perceived relatedness with individualistic and collectivistic value orientations as well as with self‐construal types were also explored. Results indicated cultural groups to be quite similar in actual relatedness, but to differ in expected and ideal relatedness, with Turks reporting more relatedness. In Turkey, lower SES adolescents reported more relatedness in ideal and actual conditions than upper SES adolescents, while they did not differ in expected relatedness. Results involving self‐types and value orientations pointed to both cross‐cultural similarities and within‐cultural diversity in relatedness. Theoretical implications of the differential impact of culture, SES, self‐construals, and value orientations on actual, ideal, and expected relatedness are discussed. Copyright © 2006 John Wiley & Sons, Ltd.
Construction of a Highly Selective and Sensitive La(III) Sensor Based on N‐(2‐Pyridyl)‐N′‐(4‐methoxyphenyl)‐thiourea for Nano Level Monitoring of La(III) Ions
Authors: Ganjali M. R. , Norouzi P. , Alizadeh T. , Tadjarodi A. , Hanifehpour Y.
Published: May 2006

N‐(2‐Pyridyl)‐N′‐(4‐methoxyphenyl)‐thiourea (PMPT) was found to be a suitable neutral ion carrier for the construction of a highly selective and sensitive La(III) membrane sensor. Poly(vinyl chloride) (PVC) based membranes of PMPT with potassium tetrakis (p‐chlorophenyl) borate (KTpClPB) as an anionic excluder and oleic acid (OA), dibutyl phthalate (DBP), benzyl acetate (BA) and o‐nitrophenyloctyl ether (NPOE) as plasticizing solvent mediators were constructed and investigated as La(III) membrane sensors. A membrane composed of PMPT‐PVC‐KTpClPB‐BA with the ratio 8.0 : 35.0 : 3.0 : 54.0 works well over a very wide concentration range (4.0×10−8 to 1.0×10−1 M) with a Nernstian slope of 19.6±0.2 mV per decade of activity between pH values of 4.0 and 9.0. The detection limit of the sensor was calculated to be 2.0×10−8 M (ca. 3.0 ppb). The sensor displays very good discrimination toward La(III) ions with regard to most common metal ions and lanthanide ions. The proposed sensor shows a short response time for whole concentration range (ca. 12 s). For evaluation of the analytical applicability of the La(III) sensor, it was successfully used as an indicator electrode for the titration of La(III) ions with EDTA. It was also applied to the determination of fluoride content of two mouth wash preparation samples and monitoring of La(III) ions in some binary and ternary mixtures.
EQCM and Fluoroelectrochemical Studies on the Catalytic Oxidation of NADH at a Pencil 8B‐Scrawled Gold Electrode with High Detection Sensitivity
Authors: Su Yuhua , Xie Qingji , Cao Zhijun , Jia Xue'en , Yao Shouzhuo
Published: May 2006

We report for the first time the effective catalytic electrooxidation of nicotinamide adenine dinucleotide (NADH) on the pencil 8B‐scrawled gold electrode of an electrochemical quartz crystal microbalance (EQCM). The EQCM allowed us to quantitatively evaluate the catalytic activity of the pencil‐scrawled Au electrode. With increasing the mass of modified pencil powders, the peak potential for NADH oxidation shifted negatively, with maximum shift of −0.35 V at saturated pencil modification; the NADH‐oxidation peak current density (jp) was also notably increased, and the jp at saturated pencil modification was found to be larger than those at conventional pencil 8B and bare Au electrodes. Sensitive amperometric detection of NADH was achieved at the gold electrode with saturated pencil modification, with low detection potential (0.4 V versus SCE), low detection limit (0.08 μmol L−1) and wide linear range (0.2–710 μmol L−1). The fluoroelectrochemical measurements of NADH at bare and pencil‐modified gold electrodes were also conducted with satisfactory results. The convenient and low‐cost modification of pencil powders on the Au electrode may have presented a new functional surface of the EQCM, which is recommended for wider applications to bioelectrochemical studies, especially in view of the EQCM's capability of providing abundant in situ information in relevant processes.
CE as orthogonal technique to HPLC for alprazolam degradation product identification
Authors: Saavedra Luis , Huidobro Angel Luis , García Antonia , Cabanelas Jose Carlos , González María G. , Barbas Coral
Published: May 2006

The control of degradation products is currently a critical issue to the pharmaceutical industry. A degradation product that appeared in alprazolam tablets during their stability assay, 7‐chloro‐1‐methyl‐5‐phenyl‐[1,2,4]triazolo[4,3‐a]quinolin‐4‐amine, also named triazolaminoquinoline, was tested as possible candidate in the HPLC method employed for the study. The impurity showed the same retention time and spectra as the degradation product; but as all these compounds are very closely related, a confirmation with an independent technique was necessary, and CE was chosen for that purpose. Problems related to the adsorption of the analytes to the negatively charged silica surface were solved by employing a new polymeric capillary coating consisting of poly(3‐aminopropylmethylsiloxane). The polymer provided EOF towards the anode, and the two compounds were separated in less than 8 min in a 60 cm total‐length capillary, 75 µm id capillary with a BGE containing 50 mM phosphate buffer at pH 2.0 with 20% ACN. When the sample containing the degradation product was injected, the presence of triazolaminoquinoline was confirmed.
Quantification of ganciclovir in human plasma using capillary electrophoresis
Authors: Saleh Soundos , Hempel Georg
Published: May 2006

A fast, simple, specific capillary electrophoretic method in the MEKC mode for the quantification of the antiviral drug ganciclovir is described. The separation was obtained using a 50 µm id fused‐silica capillary, 60 mM borax buffer (pH 9.25) containing 40 mM SDS using ethenoadenosine as the internal standard. Sample preparation was done by ultrafiltration with a Microcon 30 000 kDa filter. The analytes were detected with UV detector at 254 nm. A sufficient sensitivity was achieved by using a bubble cell capillary. The linear range was from 0.5 to 10 mg/L with a LOQ of 0.5 mg/L. Correlation coefficients were better than 0.999 whereas inter‐ and intraday precision and accuracy were less than 10.7%. The analysis of patients' samples after administration of ganciclovir indicates that the method is suitable for drug monitoring in the clinic.
Capillary electrophoresis and the clinical laboratory
Authors: Jabeen Rukhsana , Payne Deborah , Wiktorowicz John , Mohammad Amin , Petersen John
Published: May 2006

Over the past 15 years, CE as an analytical tool has shown great promise in replacing many conventional clinical laboratory methods, such as electrophoresis and HPLC. CE's appeal was that it was fast, used very small amounts of sample and reagents, was extremely versatile, and was able to separate large and small analytes, whether neutral or charged. Because of this versatility, numerous methods have been developed for analytes that are of clinical interest. Other than molecular diagnostic and forensic laboratories CE has not been able to make a major impact in the United States. In contrast, in Europe and Japan an increasing number of clinical laboratories are using CE. Now that automated multicapillary instruments are commercially available along with cost‐effective test kits, CE may yet be accepted as an instrument that will be routinely used in the clinical laboratories. This review will focus on areas where CE has the potential to have the greatest impact on the clinical laboratory. These include analyses of proteins found in serum and urine, hemoglobin (A1c and variants), carbohydrate‐deficient transferrin, forensic and therapeutic drug screening, and molecular diagnostics.
Intertidal subsidence and collapse features on wave‐exposed, drift‐aligned sandy beaches subject to Amazon mud: Cayenne, French Guiana
Authors: Anthony Edward J. , Dolique Franck
Published: May 2006

Short‐lived collapse features affecting the intertidal sandy profile were observed on mud‐rich beaches in Cayenne. They were formed in packets of beach sand accumulating over thick (several metres) fluid to under‐consolidated foreshore mud, which adjusts to this sand loading by seaward and longshore migration of fluid mud and subsequent in situ mud dewatering, thus generating subsidence and deformation of the overlying sand sheet. These sandy collapse features required active longshore sand transport and were washed out by wave processes at each rising tide. They finally disappeared permanently as adjustment of the underlying mud enabled stabilization of the beach profile. Copyright © 2006 John Wiley & Sons, Ltd.
β‐diversity fluctuations in Early–Mid Ordovician brachiopod communities of South China
Authors: Zhan R.‐B. , Jin J. , Rong J.‐Y.
Published: May 2006

Lower to Middle Ordovician transitional strata (Acrograptus filiformis Biozone to Exigraptus clavus Biozone) of the Upper Yangtze Platform contain rich and diverse brachiopods, particularly in the Daguanshan Formation of Sichuan Province, the Meitan Formation of Guizhou Province, and the Yingpan Formation of Houping, Chongqing City. On the basis of multivariate analyses of 207 samples (about 15 000 brachiopod specimens) and 61 species from these strata, 23 brachiopod‐dominated communities and associations are delineated through six graptolitic biozones (Acrograptus filiformis to Exigraptus clavus biozones). The disparity of brachiopod associations or β‐diversity, as measured by the number of contemporaneous associations across variable ecological settings, was low in the A. filiformis Biozone and increased through the overlying graptolitic biozones to reach an acme in the Azygograptus suecisus and Expansograptus hirundo biozones, where as many as nine different brachiopod associations thrived in mid‐shelf and also established in inner‐ and outer‐shelf environments. Despite a sharp increase in α‐diversity within the Didymograptellus eobifidus Biozone, β‐diversity remained relatively low, with only three distinct brachiopod communities. The diversity of brachiopod associations suffered an abrupt drop in the E. clavus Biozone, as a result of a major faunal turnover event, with only a single Metorthis Community present in an upper mid‐shelf setting. Temporally, brachiopod associations appear to be most stable in mid‐shelf settings, with the Paralenorthis, Sinorthis, Desmorthis, and Euorthisina communities having a relatively high α‐diversity and lasting through two to five graptolitic biozones. In both species composition and temporal duration, the brachiopod associations at the shallow‐ (BA1 to upper BA2) and deep‐shelf (BA4) settings are unstable, characterized by low α‐diversity and rapid vertical changes. This study implies that, during the Early and Mid Ordovician, brachiopod communities already attained a high level of organization in mid‐shelf settings, but remained poorly established in high‐stress environments of very shallow or very deep shelf settings. Copyright © 2006 John Wiley & Sons, Ltd.
MUC2 expression is regulated by histone H3 modification and DNA methylation in pancreatic cancer
Authors: Yamada Norishige , Hamada Tomofumi , Goto Masamichi , Tsutsumida Hideaki , Higashi Michiyo , Nomoto Mitsuharu , Yonezawa Suguru
Published: May 2006

Mucins are highly glycosylated proteins that play important roles in carcinogenesis. In pancreatic neoplasia, MUC2 mucin has been demonstrated as a tumor suppressor and we have reported that MUC2 is a favorable prognostic factor. Regulation of MUC2 gene expression is known to be controlled by DNA methylation, but the role of histone modification for MUC2 gene expression has yet to be clarified. Herein, we provide the first report that the histone H3 modification of the MUC2 promoter region regulates MUC2 gene expression. To investigate the histone modification and DNA methylation of the promoter region of the MUC2 gene, we treated 2 human pancreatic cancer cell lines, PANC1 (MUC2‐negative) and BxPC3 (MUC2‐positive) with the DNA methyltransferase inhibitor 5‐azacytidine (5‐aza), the histone deacetylase inhibitor trichostatin A (TSA), and a combination of these agents. The DNA methylation level of PANC1 cells was decreased by all 3 treatments, whereas histone H3‐K4/K9 methylation and H3‐K9/K27 acetylation in PANC1 cells was changed to the level in BxPC3 cells by treatment with TSA alone and with the 5‐aza/TSA combination. The expression level of MUC2 mRNA in PANC1 cells exhibited a definite increase when treated with TSA and 5‐aza/TSA, whereas 5‐aza alone induced only a slight increase. Our results suggest that histone H3 modification in the 5′ flanking region play an important role in MUC2 gene expression, possibly affecting DNA methylation. An understanding of these intimately correlated epigenetic changes may be of importance for predicting the outcome of patients with pancreatic neoplasms. © 2006 Wiley‐Liss, Inc.
H‐Ras selectively up‐regulates MMP‐9 and COX‐2 through activation of ERK1/2 and NF‐κB: An implication for invasive phenotype in rat liver epithelial cells
Authors: Lee Ki Won , Kim Mi‐Sung , Kang Nam Joo , Kim Do‐Hee , Surh Young‐Joon , Lee Hyong Joo , Moon Aree
Published: May 2006

One of the most frequent events in carcinogenesis is uncontrolled activation of Ras signaling pathway. A previous study demonstrated that the introduction of H‐Ras into the normal WB‐F344 rat liver epithelial (WB) cell line and adult male F344 rats resulted in tumorigenicity. The present study investigated whether H‐Ras induced the invasive and migrative phenotypes in WB cells, and subsequently aimed at characterizing the underlying mechanisms. H‐Ras induced the invasive and migrative phenotypes of WB cells with a selective up‐regulation of matrix metalloproteinase (MMP)‐9, but not MMP‐2. Cyclooxygenase (COX)‐2 and the subsequent production of prostaglandin E2(PGE2) were also induced by H‐Ras. Treatment of H‐Ras WB cells with GM6001 and NS398, the inhibitors of MMPs and COX‐2, respectively, significantly inhibited the H‐Ras‐induced invasive and migrative phenotypes. DNA binding activity of nuclear factor (NF)‐κB, but not that of activator protein (AP)‐1, was increased by H‐Ras. Caffeic acid phenethyl ester and Bay 11‐7082, specific inhibitors of NF‐κB and IKK, respectively, significantly inhibited the expression of MMP‐9 and COX‐2, invasion and migration of H‐Ras WB cells, revealing NF‐κB as a transcriptional factor responsible for H‐Ras‐induced malignant phenotypic conversion of WB cells. Activation of ERKs pathway was critical for H‐Ras‐induced invasive and migrative phenotypes, up‐regulation of MMP‐9 and COX‐2 as well as enhanced DNA binding activity of NF‐κB in WB cells. Taken together, these results demonstrate that H‐Ras up‐regulates MMP‐9 and COX‐2 through activation of ERKs and IKK‐IκBα‐NF‐κB signal pathway which may contribute to the malignant progression of WB rat liver epithelial cells. © 2006 Wiley‐Liss, Inc.
Prediction of recurrence in Ta urothelial cell carcinoma by real‐time quantitative PCR analysis: A microarray validation study
Authors: Schultz Iman J. , Wester Kenneth , Straatman Huub , Kiemeney Lambertus A. , Babjuk Marko , Mares Jaroslav , Willems Johanner L. , Swinkels Dorine W. , Witjes J. Alfred , de Kok Jacques B. , Malmström Per‐Uno
Published: May 2006

Accurate prediction of tumor recurrence in patients with superficial urothelial cell carcinoma (UCC) might result in a significant reduction of invasive follow‐up cystoscopies. A recent study identified a panel of 26 genes from a large cDNA microarray analysis of bladder tumors that discriminated between early‐ and late‐recurring patients with superficial Ta tumors (Dyrskjøt et al., Nat Genet 2003;33:90–6). We aimed to validate this panel of genes in 44 primary Ta UCCs (23 and 21 tumors from patients with short or prolonged recurrence‐free periods, respectively), by real‐time quantitative PCR. Statistical analysis showed marginal significant different mRNA expression levels between the 2 patient groups. To evaluate a supplementary effect of genes for the identification of patients with short or prolonged recurrence‐free intervals, forward logistic regression analysis was applied. This revealed that a combination of the expression profiles of the genes HNRPK, LTB4DH and ANP32B resulted in the best performance, although the combination only marginally increased the predictive value of HNRPK alone. Comparing the receiver‐operating‐characteristic curves for HNRPK expression among patients with short or prolonged recurrence‐free periods, revealed an area under the curve of 0.696 (95% CI, 0.537–0.855). Using the median HNRPK expression level as cut‐off, a sensitivity of 69.6% and a specificity of 71.4% were obtained for the identification of patients with short or prolonged recurrence‐free periods, respectively. In conclusion, we were not able to confirm the microarray gene expression pattern of the 26 genes shown by Dyrskjøt et al. The discovery of accurate recurrence predictive markers, therefore, remains a challenge. © 2006 Wiley‐Liss, Inc.
High incidence of EMMPRIN expression in human tumors
Authors: Riethdorf Sabine , Reimers Natalie , Assmann Volker , Kornfeld Jan‐Wilhelm , Terracciano Luigi , Sauter Guido , Pantel Klaus
Published: May 2006

Extracellular matrix metalloproteinase inducer expressed by tumor cells stimulates peritumoral fibroblasts to produce matrix metalloproteinases, thus contributing to tumor invasion and metastasis. To assess its suitability as potential therapeutic target, the overall incidence of EMMPRIN expression in normal and neoplastic tissues was analyzed. EMMPRIN expression was detected immunohistochemically using monoclonal antibodies MEM‐M6/1 and HIM6 and tissue microarrays with 2,348 and 608 tissue samples from 129 distinct tumor types and 76 different normal tissues, respectively. Expression and glycosylation state of EMMPRIN in human breast cancer cells were analyzed by Western blot analysis with monoclonal antibodies recognizing distinct carbohydrate structures and biochemical methods. EMMPRIN expression was found in 112 of 129 tumor entities analyzed with malignant tumors being EMMPRIN positive more frequently than benign tumors. A remarkable heterogeneity in EMMPRIN expression between tumor entities was observed. Among others, squamous‐cell carcinomas (60–100%), pancreatic (87%), chromophobic kidney (83%), hepatocellular (83%) or medullary breast (83%) adenocarcinomas as well as glioblastoma multiforme (79%) presented with a particular high incidence of EMMPRIN expression. There were a limited number of EMMPRIN‐positive normal cell types including proliferatively active and differentiating epithelial cells, germ cells, myocardial cells in the left heart ventricle or vascular endothelial cells of the brain. We could further demonstrate that breast cancer cells expressed EMMPRIN isoforms differing in the presence or absence of LewisX glycan structures. Our results may assist in defining the suitability of EMMPRIN as therapeutic target and predicting negative side effects. © 2006 Wiley‐Liss, Inc.
Mannose‐binding lectin‐2 genetic variation and stomach cancer risk
Authors: Baccarelli Andrea , Hou Lifang , Chen Jinbo , Lissowska Jolanta , El‐Omar Emad M. , Grillo Paolo , Giacomini Sara M. , Yaeger Meredith , Bernig Toralf , Zatonski Witold , Fraumeni Joseph F. , Chanock Stephen J. , Chow Wong‐Ho
Published: May 2006

Deficiency of the mannose‐binding lectin (MBL) protein, an antigen‐recognition molecule involved in systemic and mucosal innate immunity, is determined by variant alleles in MBL2 gene promoter and exon‐1 regions. We conducted a population‐based study on 305 stomach cancer cases and 427 controls in Warsaw, Poland to determine whether MBL2 gene variants predispose to stomach cancer. Single nucleotide polymorphisms (SNPs) in MBL2 were determined by TaqMan™. The 5 tested MBL2 variants are in complete linkage disequilibrium and comprise 6 different haplotypes. The risk of stomach cancer was increased in subjects carrying the H/H promoter genotype (OR = 1.8, 95%CI 1.1–2.9; p = 0.020) relative to L/L carriers, after adjustment for age, gender, education and smoking. Carrying at least one D exon‐1 allele was associated with nonsignificant excess risk (OR = 1.5, 95% CI 0.9–2.4; p = 0.081). In haplotype analysis, the HYD haplotype was associated with increased risk of stomach cancer when compared with HYA, the most common haplotype (OR = 1.9, 95% CI 1.1–3.2; p = 0.021). In diplotype analysis, subjects carrying the YA/D haplotype combination showed the highest risk (OR = 3.0, 95% CI 1.2–7.1; p = 0.015), compared with YA/YA. Further analyses to examine the joint effect of MBL2 and IL‐1B polymorphisms, previously shown to predispose to stomach cancer, indicated that the combination of at‐risk IL‐1B genotypes (CT or TT at location ‐511) and HYD MBL2 haplotype was associated with a 3.5‐fold risk (OR = 3.5, 95% CI 1.6–7.6; p = 0.001). Our findings suggest that the codon 52 D MBL2 variant causing a cysteine > arginine replacement, but not B and C variants producing glycine substitutions, is specifically associated with gastric cancer risk. © 2006 Wiley‐Liss, Inc.
Prevention of oxidative degradation of polyurethane by covalent attachment of di‐tert‐butylphenol residues
Authors: Stachelek Stanley J. , Alferiev Ivan , Choi Hoon , Chan Chun Wai , Zubiate Brett , Sacks Michael , Composto Russell , Chen I‐Wei , Levy Robert J.
Published: May 2006

Polyurethane (PU) components of cardiovascular devices are subjected to oxidation‐initiated surface degradation, which leads to cracking and ultimately device failure. In the present study, we investigated a novel bromoalkylation chemical strategy to covalently attach the antioxidant, di‐tert‐butylphenol (DBP), and/or cholesterol (Chol) to the PU urethane nitrogen groups to hypothetically prevent oxidative degradation. These experiments compared PU, PU‐DBP, PU‐Chol, and PU‐Chol‐DBP. A series of comparative oxidative degradation studies involved exposing PU samples (modified and unmodified) to H2O2–CoCl2 for 15 days at 37°C, to cause accelerated oxidative degradation. The extent and effects of degradation were assessed by attenuated total reflectance Fourier transformation infrared spectroscopy (FTIR), scanning electron microscopy (SEM), surface contact angle measurements, and mechanical testing. Both the Chol and DBP modification conferred significant resistance to oxidation related changes compared to unmodified PU per FTIR and SEM results. SEM demonstrated cavitation only in unmodified PU. However, contact angle analysis showed significant oxidation‐induced changes only in the Chol‐modified PU formulations. Most importantly, uniaxial stress–strain testing revealed that only PU‐DBP demonstrated bulk elastomeric properties that were minimally affected by oxidation; PU, PU‐Chol, PU‐Chol‐DBP showed marked deterioration of their stress–strain properties following oxidation. In conclusion, these results demonstrate that derivatizing PU with DBP confers significant resistance to oxidative degradation compared with unmodified PU. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Different signaling responses to anti‐proliferative agents in human aortic and venous smooth muscle cells
Authors: Lee Ray M. , Masaki Takahisa , Yang Hung‐Sheng , Liu Jihua , Chen Jun , Li Li , Blumenthal Donald K. , Cheung Alfred K.
Published: May 2006

Proliferation of smooth muscle cells (SMCs) contributes to the stenosis of coronary arteries and vascular grafts. Local delivery of anti‐proliferative drugs can prevent vascular stenosis. To understand the cellular responses to anti‐proliferative agents, we investigated the signaling events in cultured human aortic SMCs (ASMCs), saphenous venous SMCs (VSMCs), and dermal fibroblasts (DFs) in response to paclitaxel or etoposide. Cellular mitochondrial and proliferative activities were examined with the methylthiazoletetrazolium (MTT) dye reduction and the bromodeoxyuridine (BrdU) incorporation assay, respectively. Cell proliferation was almost completely suppressed by paclitaxel or etoposide, but apoptosis was achieved in only about 50% of cells at the highest drug concentrations, suggesting the presence of compensatory mechanisms to prevent apoptosis. Examination of three important signaling pathways revealed significant differences between ASMCs, VSMCs, and DFs. Treatment with either paclitaxel or etoposide caused a transient phosphorylation/activation of p42 MAPK in ASMCs and DFs, but had no effect on phospho‐p42/44 MAPK in VSMCs. High‐dose etoposide enhanced p38 MAPK activation in ASMCs, but not in VSMCs. The p38 inhibitor, PD169316, partially inhibited etoposide‐induced ASMC apoptosis, but induced apoptosis in VSMCs. The effects of etoposide and paclitaxel on Akt also differed between ASMCs and VSMCs. These observations indicate that ASMCs and VSMCs differ in the response of signaling pathways to anti‐proliferative agents. In ASMCs, p42/44 MAPK appears to serve a pro‐survival role, whereas p38 MAPK is a pro‐apoptotic regulator. In contrast, p38 MAPK is an important pro‐survival regulator in VSMCs and p42/44 MAPK appears to play a minor role in responding to anti‐proliferative drugs. J. Cell. Biochem. 99: 835–844, 2006. © 2006 Wiley‐Liss, Inc.
Differential expression of voltage‐activated calcium currents in zebrafish retinal ganglion cells
Authors: Huang Luoxiu , Li Lei
Published: May 2006

We report a study on the characterization of voltage‐activated calcium currents (ICa) in retinal ganglion cells (RGCs) and the topographic distribution of RGCs that express different types of ICa in zebrafish retinas. In acutely isolated zebrafish RGCs, both high‐voltage‐activated (HVA; peak activation potential +7.4 ± 1.1 mV) and low‐voltage‐activated (LVA; peak activation potential –33.0 ± 1.2 mV) ICa were recorded. HVA ICa were recorded in all of the tested RGCs, whereas LVA ICa were recorded in approximately one‐third of the tested cells. In RGCs that expressed both HVA and LVA ICa, the two currents were readily separated by depolarizing the cell membrane to different voltages from different holding potentials. Among RGCs that expressed LVA ICa, some cells expressed large LVA ICa (up to 130 pA), whereas others expressed small LVA ICa (approximately 20 pA). RGCs that expressed large and small LVA ICa were designated as class I and class II cells, respectively, and RGCs that expressed only HVA ICa were designated as class III cells. The topographic distribution of cell classes was similar in various areas of the retina. In the nasal‐ventral retina, for example, class III cells outnumbered class I and class II cells by 10.8‐ and 2.6‐fold, respectively. In the temporal and dorsal retinas, the density of class III cells slightly decreased, whereas the density of class I and class II cells increased. The differential expression of ICa in RGCs may correlate with the development and function of the retina. © 2006 Wiley‐Liss, Inc.
A comparative evaluation of random and site‐specific immobilization techniques for the preparation of antibody‐based chiral stationary phases
Authors: Franco Elliott J. , Hofstetter Heike , Hofstetter Oliver
Published: May 2006

In this study, one random and four site‐directed conjugation strategies were applied to immobilize an mAb, which stereoselectively binds toL‐amino acids, onto silica particles. The resulting chiral stationary phases (CSPs) were used for enantiomer separation of the model‐analyteD,L‐phenylalanine and further examined in frontal affinity chromatography. Although random immobilization of the antibody onto discuccinimidyl carbonate‐activated silica resulted in a CSP that enabled baseline separation of the enantiomers ofD,L‐phenylalanine, the amount of available binding sites was considerably lower compared to the CSPs prepared by site‐directed strategies. Immobilization of antibodyviaits carbohydrate chains, either directlyviahydrazone bonds between the support and the protein or indirectlyviabinding carbohydrate‐biotinylated antibody to streptavidin‐derivatized silica, resulted in medium column efficiencies. Higher amounts of available active sites were obtained by immobilizing the antibody indirectly through the “crystallizable fragment (Fc)” receptor protein A/G. The best results with regard to amount of available binding sites and column efficiency were obtained by first biotinylating the antibody specifically at its C‐termini using carboxypeptidase Y and immobilizing the biotinylated antibody on streptavidin‐derivatized silica.
Melt Structure and its Transformation by Sequential Crystallization of the Two Blocks within Poly(L‐lactide)‐block‐Poly(ε‐caprolactone) Double Crystalline Diblock Copolymers
Authors: Hamley I. W. , Parras P. , Castelletto V. , Castillo R. V. , Müller A. J. , Pollet E. , Dubois P. , Martin C. M.
Published: May 2006

Summary:Sequential crystallization of poly(L‐lactide) (PLLA) followed by poly(ε‐caprolactone) (PCL) in double crystalline PLLA‐b‐PCL diblock copolymers is studied by differential scanning calorimetry (DSC), polarized optical microscopy (POM), wide‐angle X‐ray scattering (WAXS) and small‐angle X‐ray scattering (SAXS). Three samples with different compositions are studied. The sample with the shortest PLLA block (32 wt.‐% PLLA) crystallizes from a homogeneous melt, the other two (with 44 and 60% PLLA) from microphase separated structures. The microphase structure of the melt is changed as PLLA crystallizes at 122 °C (a temperature at which the PCL block is molten) forming spherulites regardless of composition, even with 32% PLLA. SAXS indicates that a lamellar structure with a different periodicity than that obtained in the melt forms (for melt segregated samples). Where PCL is the majority block, PCL crystallization at 42 °C following PLLA crystallization leads to rearrangement of the lamellar structure, as observed by SAXS, possibly due to local melting at the interphases between domains. POM results showed that PCL crystallizes within previously formed PLLA spherulites. WAXS data indicate that the PLLA unit cell is modified by crystallization of PCL, at least for the two majority PCL samples. The PCL minority sample did not crystallize at 42 °C (well below the PCL homopolymer crystallization temperature), pointing to the influence of pre‐crystallization of PLLA on PCL crystallization, although it did crystallize at lower temperature. Crystallization kinetics were examined by DSC and WAXS, with good agreement in general. The crystallization rate of PLLA decreased with increase in PCL content in the copolymers. The crystallization rate of PCL decreased with increasing PLLA content. The Avrami exponents were in general depressed for both components in the block copolymers compared to the parent homopolymers.

Polarized optical micrographs during isothermal crystallization of (a) homo‐PLLA, (b) homo‐PCL, (c) and (d) block copolymer after 30 min at 122 °C and after 15 min at 42 °C.

magnified image

Polarized optical micrographs during isothermal crystallization of (a) homo‐PLLA, (b) homo‐PCL, (c) and (d) block copolymer after 30 min at 122 °C and after 15 min at 42 °C.
Familial essential tremor with apparent autosomal dominant inheritance: Should we also consider other inheritance modes?
Authors: Ma Shaochun , Davis Thomas L. , Blair Marcia A. , Fang John Y. , Bradford Yuki , Haines Jonathan L. , Hedera Peter
Published: May 2006

A positive family history is present in many patients with essential tremor (ET), but twin studies and segregation analysis have suggested that ET is not entirely a genetic disorder. Two genetic loci have been identified in autosomal dominant (AD) ET and polymorphisms in the DRD3 and HS1‐BP3 genes have been proposed as the possible susceptibility factors for ET. There is also evidence for further genetic heterogeneity. We evaluated 4 unrelated large kindreds with ET with an apparent AD mode of transmission. Each kindred spanned at least 3 generations and contained at least 13 living affected subjects who met criteria for definitive ET. None of the pedigrees had evidence for inheritance of ET from both parents. Known genetic ET loci were excluded in these families. We detected a preferential transmission of ET in every kindred and the proportion of affected offspring varied from 75% to 90% (P < 0.05) in the generations with complete ascertainment. Our data indicate that non‐Mendelian preferential transmission of an affected allele is a feature in many ET kindreds with multiple affected members and an apparent AD mode of inheritance. ET may have a complex etiology. Additional genetic models need to be considered, including an interaction of susceptibility genes and environmental risk factors. © 2006 Movement Disorder Society
Natural linewidth chemical shift imaging (NL‐CSI)
Authors: Bashir Adil , Yablonskiy Dmitriy A.
Published: May 2006

The discrete Fourier transform (FT) is a conventional method for spatial reconstruction of chemical shifting imaging (CSI) data. Due to point spread function (PSF) effects, FT reconstruction leads to intervoxel signal leakage (Gibbs ringing). Spectral localization by imaging (SLIM) reconstruction was previously proposed to overcome this intervoxel signal contamination. However, the existence of magnetic field inhomogeneities creates an additional source of intervoxel signal leakage. It is demonstrated herein that even small field inhomogeneities substantially amplify intervoxel signal leakage in both FT and SLIM reconstruction approaches. A new CSI data acquisition strategy and reconstruction algorithm (natural linewidth (NL) CSI) is presented that eliminates effects of magnetic field inhomogeneity‐induced intervoxel signal leakage and intravoxel phase dispersion on acquired data. The approach is based on acquired CSI data, high‐resolution images, and magnetic field maps. The data are reconstructed based on the imaged object structure (as in the SLIM approach) and a reconstruction matrix that takes into account the inhomogeneous field distribution inside anatomically homogeneous compartments. Phantom and in vivo results show that the new method allows field inhomogeneity effects from the acquired MR signal to be removed so that the signal decay is determined only by the “natural” R2 relaxation rate constant (hence the term “natural linewidth” CSI). Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Error and convergence of two numerical schemes for stochastic differential equations
Authors: Ewald Brian D.
Published: May 2006

We examine the convergence and error rate of two stochastic numerical schemes using the method of proof used by G. N. Mil'shtein (Theory Prob Appl 19 (1974), 557–562). © 2006 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2006.