bluuebunny/crossref_metadata_2025 huggingface dataset:
A systematic review of prevalence studies of depression in Parkinson's disease
Authors: Reijnders Jennifer S.A.M. , Ehrt Uwe , Weber Wim E.J. , Aarsland Dag , Leentjens Albert F.G.
Published: November 2007

Prevalence rates of depressive disorders in Parkinson's disease (PD) vary widely across studies, ranging from 2.7% to more than 90%. The aim of this systematic review was to calculate average prevalences of depressive disorders taking into account the different settings and different diagnostic approaches of studies. Using Medline on Pubmed, a systematic literature search was carried out for studies of depression in Parkinson's disease. A total of 104 articles were included and assessed for quality; 51 articles fulfilled the quality criteria. Multiple publications from the same database were not included in the meta‐analysis. In the remaining 36 articles, the weighted prevalence of major depressive disorder was 17% of PD patients, that of minor depression 22% and dysthymia 13%. Clinically significant depressive symptoms, irrespective of the presence of a DSM defined depressive disorder, were present in 35%. In studies using a (semi) structured interview to establish DSM criteria, the reported prevalence of major depressive disorder was 19%, while in studies using DSM criteria without a structured interview, the reported prevalence of major depressive disorder was 7%. Population studies report lower prevalence rates for both major depressive disorder and the clinically significant depressive symptoms than studies in other settings. This systematic review suggests that the average prevalence of major depressive disorder in PD is substantial, but lower than generally assumed. © 2007 Movement Disorder Society
Recent advances in plant hepatoprotectives: A chemical and biological profile of some important leads
Authors: Negi Arvind S. , Kumar J.K. , Luqman Suaib , Shanker Karuna , Gupta M.M. , Khanuja S.P.S.
Published: November 2007

Medicinal plants have been traditionally used for treating liver diseases since centuries. Several leads from plant sources have been found as potential hepatoprotective agents with diverse chemical structures. Although, a big list of hepatoprotective phytomolecules was reported in the scientific literature, only a few were potent against various types of liver damages. Of which, silymarin, andrographolide, neoandrographolide, curcumin, picroside, kutkoside, phyllanthin, hypophyllanthin, and glycyrrhizin have largely attracted the scientific community. This review focuses discussion on the chemistry, biological activity, mode of action, toxicity, and future prospects of these leads. © 2007 Wiley Periodicals, Inc. Med Res Rev, 28, No. 5, 746–772, 2008
Apoptosis‐inducing activity of hydroxylated polymethoxyflavones and polymethoxyflavones from orange peel in human breast cancer cells
Authors: Sergeev Igor N. , Ho Chi‐Tang , Li Shiming , Colby Julie , Dushenkov Slavik
Published: November 2007

Sweet orange (Citrus sinensisL.) peel is a rich resource of flavonoids, especially polymethoxyflavones (PMFs). Citrus flavonoids exert a broad spectrum of biological activity, including antiproliferative and proapoptotic effects in cancer cells. We have recently shown that individual PMFs from orange peel induce Ca2+‐mediated apoptosis in human breast cancer cells and that hydroxylation of PMFs is critical for enhancing their proapoptotic activaty. Here, we report that the fraction of orange peel extract containing a mixture of non‐hydroxylated PMFs (75.1%) and hydroxylated PMFs (5.44%) and the fraction containing only hydroxylated PMFs (97.2%) induce apoptosis in those cells as well. Treatment of MCF‐7 breast cancer cells with these fractions inhibited growth and induced apoptosis associated with an increase in the basal level of intracellular Ca2+. Effective concentrations of the hydroxylated PMFs fraction in inhibiting growth, inducing apoptosis, and increasing intracellular Ca2+were lower than those of the non‐hydroxylated PMFs fraction. Our results strongly imply that bioactive PMFs from orange peel exert proapoptotic activity in human breast cancer cells, which depends on their ability to induce an increase in intracellular Ca2+and thus, activate Ca2+‐dependent apoptotic proteases.
The anti‐invasive effect of lucidenic acids isolated from a new Ganoderma lucidum strain
Authors: Weng Chia‐Jui , Chau Chi‐Fai , Chen Kuang‐Dee , Chen Deng‐Hai , Yen Gow‐Chin
Published: November 2007

Ganoderma lucidum is a well‐known mushroom with various pharmacological effects that has been used for health and longevity purposes. The objective of this study was to investigate the anti‐invasive effect of lucidenic acids isolated from a new G. lucidum strain (YK‐02) against human hepatoma carcinoma (HepG2) cells. Triterpenoid components in the ethanol extract of G. lucidum (YK‐02) were separated by means of a semi‐preparative RP HPLC. Four major peaks were separated and crystallized from triterpenoids fraction, and were identified as lucidenic acids A, B, C, and N according to their spectroscopic values of 1H NMR and MS. Treatment of the lucidenic acids (50 μM) in the presence of 200 nM phorbol 12‐myristate 13‐acetate (PMA) after 24 h of incubation all resulted in significant inhibitory effects on PMA‐induced MMP‐9 activity and invasion of HepG2 cells. The results indicate that the lucidenic acids isolated from G. lucidum (YK‐02) are anti‐invasive bioactive components on hepatoma cells.
Protective effect of dietary tomatine against dibenzo[a,l]pyrene (DBP)‐induced liver and stomach tumors in rainbow trout
Authors: Friedman Mendel , McQuistan Tammie , Hendricks Jerry D. , Pereira Cliff , Bailey George S.
Published: November 2007

The potential anti‐carcinogenic effects of tomatine, a mixture of commercial tomato glycoalkaloids α‐tomatine and dehydrotomatine (10:1), were examined in the rainbow trout chemoprevention model. Prior to the chemoprevention study, a preliminary toxicity study revealed that tomatine in the diet fed daily at doses from 100 to 2000 parts per million (ppm) for 4 weeks was not toxic to trout. For the tumor study, replicate groups of 105 trout were fed diets containing dibenzo[a,l]pyrene (DBP) alone (224 ppm), (N = 3), DBP plus tomatine at 2000 ppm (N = 2), tomatine alone (N = 2), or control diet (N = 2) for 4 weeks. The fish were then returned to control diet for 8 months and necropsied for histopathology. Dietary tomatine was found to reduce DBP‐initiated liver tumor incidence from 37.0 to 19.0% and stomach tumor incidence from 46.4 to 29.4%. Tomatine also reduced stomach tumor multiplicity. The tomatine‐containing diets did not induce mortality, change in fish weights, or liver weights. No adverse pathological effects in the tissues of the fish on the tomatine diets were observed. Dose‐response and chemopreventive mechanisms for tomatine protection remain to be examined. This is the first report on the anticarcinogenic effects of tomatine in vivo.
Thermal degradation of anthocyanins and its impact on color andin vitroantioxidant capacity
Authors: Sadilova Eva , Carle Reinhold , Stintzing Florian C.
Published: November 2007

The aim of the current study was to thoroughly investigate the structural changes of anthocyanins at pH 3.5 in purified fractions from black carrot, elderberry and strawberry heated over 6 h at 95°C. Degradation products were monitored by HPLC‐DAD‐MS3to elucidate the prevailing degradation pathways. In addition, alterations of color and antioxidant properties observed upon heating were scrutinized. Most interestingly, the degradation pathways at pH 3.5 were found to differ from those at pH 1. Among others, chalcone glycosides were detected at 320 nm in heat‐treated elderberry and strawberry pigment isolates, and opening of the pyrylium ring initiated anthocyanin degradation. In the case of acylated anthocyanins, acyl‐glycoside moieties were split off from the flavylium backbone, first. Finally, for all pigment isolates, phenolic acids and phloroglucinaldehyde were the terminal degradation products as remainders of the B‐ and A‐ring, respectively. Maximum and minimum antioxidant stabilizing capacities were found in black carrot and strawberry, respectively, which was explained by the high degree of acylation in the former. After heating, decline of trolox equivalent antioxidant capacity (TEAC) was observed in all samples, which was attributed to both anthocyanins and their colorless degradation products following thermal exposure. As deduced from the ratio of TEAC value and anthocyanin content, the loss of anthocyanin bioactivity could not be compensated by the antioxidant capacity of newly formed colorless phenolics upon heating.
Sociocultural studies of families of children with intellectual disabilities
Authors: Skinner Debra , Weisner Thomas S.
Published: November 2007

This article reviews recent sociocultural studies of families of children with intellectual disabilities to introduce the range of research conducted from this perspective and to highlight the methodological, conceptual, and theoretical contributions of this approach to the study of mental retardation. Sociocultural studies examine families within their cultural, historical, and sociopolitical contexts. This type of research is comparative across different cultural groups, but is not limited to such comparisons. Sociocultural studies use varied theories and methods, but they share a focus on families' coproduction of meanings and practices related to intellectual disability; families' responses and adaptations to disability; and how their understandings and experiences are shaped within larger social institutions and inequities. Sociocultural approaches take into account community contexts that matter to families with members with mental retardation or developmental delay, and they examine the broader systems that define and position individuals with disabilities and their families. As a whole, these studies provide a more experiential and holistic view of families' beliefs and adaptations within sociopolitical worlds, and offer new tools by which to study the families of children with developmental delays within and across different cultural groups. © 2007 Wiley‐Liss, Inc. MRDD Research Reviews 2007;13:302–312.
Siblings of individuals with autism spectrum disorders across the life course
Authors: Orsmond Gael I. , Seltzer Marsha Mailick
Published: November 2007

In this article, we review the literature on siblings of individuals with autism spectrum disorders (ASD) from a lifespan developmental perspective, from infancy through adulthood, focusing on the sibling relationship and sibling well‐being. We situate this review within the larger body of research on siblings of individuals with developmental disabilities (DD) across the lifespan. We then consider the genetic aspects of ASDs and their implications for siblings. We conclude that there is an evidence of atypical social and communication development in some siblings of children with an ASD during infancy. During childhood and adolescence, siblings describe both positive and negative aspects of their sibling relationship and there is some evidence that siblings of children with an ASD may be at heightened risk for social and behavioral adjustment problems. The limited research on adulthood suggests that lack of closeness in the sibling relationship and social and emotional difficulties may continue. We encourage more attention focused on developmental issues, specifically with respect to samples in narrower age groups and in longitudinal research. Finally, we note the variability in sibling outcomes, and suggest further examination of potential moderating and mediating factors, including genetic predispositions. © 2007 Wiley‐Liss, Inc. MRDD Research Reviews 2007;13:313–320.
Maternal depression and developmental disability: Research critique
Authors: Bailey Donald B. , Golden Robert N. , Roberts Jane , Ford Amy
Published: November 2007

Maternal depression in families having a child with a disability has been the subject of considerable research over the past 25 years. This review was designed to describe the literature on maternal depression, critique its research methodology, identify consensus findings across studies, and make recommendations for future research. A particular emphasis is on the distinction between exhibiting depressive symptoms and meeting clinical criteria for a depressive disorder, how or whether research studies made this distinction, and implications for our understanding of maternal adaptation to disability in a family member. Of the 42 articles reviewed, only eight were clinically diagnosed depression; most of them used a scale rating depressive symptoms. Across the studies, mothers of children with disabilities generally exhibited a higher than average rate of depressive symptoms and are more at risk for clinical depression, but the incidence may be lower than reported in previous literature. Child behavior problems, maternal stress, coping style, and support were consistently associated with depressive symptoms. We conclude that we know relatively little about clinical depression in mothers of children with disabilities. The distinction between clinical depression and depressive symptoms may be important in conceptualizing how a child with a disability can influence family members and the nature of support that may need to be provided. Future research should incorporate gold standard diagnostic tools and assess history, severity, and type of depression. Research is also needed to study treatments to reduce the occurrence of both depressive symptoms and clinical depression. © 2007 Wiley‐Liss, Inc. MRDD Research Reviews 2007;13:321–329.
Conceptualization and measurement of family outcomes associated with families of individuals with intellectual disabilities
Authors: Turnbull Ann P. , Summers Jean Ann , Lee Suk‐Hyang , Kyzar Kathleen
Published: November 2007

The purpose of this review is to (a) document the current status of conceptualizing and measuring family outcomes related to having a member with an intellectual disability and (b) determine the extent to which family research focuses on internal family characteristics as contrasted to external family support. The reviewers collected 28 articles using the terms well‐being, adaptation, family functioning, or family quality of life in the title. Results of our analyses are presented as a comparison between well‐being, adaptation, and family functioning articles in one group and family quality of life articles in a second group. Both groups lacked explicit conceptual definitions, theory, and random/representative samples. The articles placed an undue emphasis on maternal participation, and tended to report a single family member score as representative of the whole family. Two major differences between the groups was a tendency for family quality of life studies to be grounded in conceptual frameworks and focus on new instrument development. Recommendations for future research directions are included. © 2007 Wiley‐Liss, Inc. MRDD Research Reviews 2007;13:346–356.
Primary and secondary effects of parenting and stress management interventions for parents of children with developmental disabilities: A meta‐analysis
Authors: Singer George H.S. , Ethridge Brandy L. , Aldana Sandra I.
Published: November 2007

A meta‐analysis of the group intervention research for parents of children with developmental disabilities was conducted in order to characterize the efficacy of treatments in reducing depressive symptoms and other forms of psychological distress associated with stress in parents of children with developmental disabilities. An extensive search led to the identification of 17 studies which were divided into three categories for comparative purposes: parenting education studies usually based on behavioral parent training, coping skills education studies based primarily on cognitive behavioral training, and studies that combined these methods along with other support services. Studies were rated for the quality of the research designs and of the reports. Consistent positive benefits were found in the form of reductions in parents' distress, and these effects were comparable to those reported in other syntheses of parenting interventions for parents of children without disabilities. The studies were evaluated in order to assess whether or not they met standards for established evidence‐based practices. On the basis of the quality and number of the randomized trials, we present evidence to support the claim that there are established evidence‐based interventions for reducing psychological distress at least in middle‐class mothers in the short term. The interventions for fathers are promising as are the data on somewhat longer‐term effects. The need for replications with a more diverse group of parents and longer‐term follow‐up were discussed. Multiple component interventions addressing both parent well‐being and behavioral parent training were significantly more effective than either behavioral parent training or cognitive behavioral training along. © 2007 Wiley‐Liss, Inc. MRDD Research Reviews 2007;13:357–369.
The role of maternal responsivity in the development of children with intellectual disabilities
Authors: Warren Steven F. , Brady Nancy C.
Published: November 2007

There is growing evidence that cumulative exposure to highly responsive parenting styles throughout the early childhood period may provide a variety of important child benefits in terms of language, cognitive, social, and emotional development. We view maternal responsivity as a dynamic construct of central importance to the development of children with intellectual disabilities just as it is for typically developing children. In this study, we selectively review the theoretical and conceptual evidence for the effects of responsivity on development, discuss factors known to influence responsivity including the nature of a child's disability, and review intervention approaches intended to enhance maternal responsivity. We conclude with a set of recommendations for future research. © 2007 Wiley‐Liss, Inc. MRDD Research Reviews 2007;13:330–338.
(Mini)emulsion Polymerization: Effect of the Segregation Degree on Polymer Architecture
Authors: González Iker , Paulis Maria , de la Cal José C. , Asua José M.
Published: November 2007

A continuous loop reactor was used for the production of 2‐ethylhexyl acrylate (2‐EHA), methyl methacrylate (MMA) and acrylic acid (AA) pressure sensitive adhesive by both emulsion and miniemulsion polymerization. Similar high monomer conversions were achieved in both processes, but striking differences in polymer architecture were found. A mathematical model was used to analyze these differences concluding that because the costabilizer suppressed monomer diffusion from miniemulsion droplets, the average polymer concentration in the polymerization loci was lower in the miniemulsion process. This resulted in less chain transfer to polymer, and hence in lower sol molecular weight and gel content.

magnified image
Higher‐order natural element methods: Towards an isogeometric meshless method
Authors: González David , Cueto Elías , Doblaré Manuel
Published: November 2007

The problem of generalizing the natural element method (NEM) in terms of higher‐order consistency and continuity is addressed here. It is done by means of the de Boor algorithm, the same employed to obtain B‐splines by linear combinations of linear interpolants in one dimension. By noting that any form of natural neighbour interpolation can be considered as a suitable generalization of linear interpolation to two and higher dimensions, the de Boor algorithm is extended to two or higher dimensions, thus obtaining a new form of interpolation that can be used in a Galerkin framework to develop a new class of meshless methods.

This new class of meshless methods closely resembles the isogeometric analysis developed by Hughes et al. (Comput. Methods Appl. Mech. Eng. 2005; 194:4135–4195). However, unlike B‐splines, the new class of interpolants does not rely on an underlying tensor‐product quadrilateral mesh. It is based on the Delaunay triangulation of the cloud of knots and does not require any regularity on the connectivity.

In addition, the new method conserves many of the attractive features of the NEM, such as strict interpolation on the boundary, and thus directs imposition of essential boundary conditions. After a theoretical description of the proposed method, some numerical examples are shown to test its performance in the context of linear elastostatics. Copyright © 2007 John Wiley & Sons, Ltd.
A case of squamosal craniosynostosis from the 16th century southeastern United States
Authors: Duncan W. N. , Stojanowski C. M.
Published: November 2007

This paper describes a case of plagiocephaly stemming from a unilateral synostosis of the left squamosal and coronal sutures in a 16th century calvaria from Georgia. Although cases of squamosal involvement in syndromic, multisuture synostotic cases have been found in the archaeological record, isolated squamosal involvement is quite rare. Our literature review found only 15 such cases reported, and this is the first case to be reported from the southeastern United States. Despite the fact that the bevelled nature of the squamosal suture is unique in the human body and that the cause for squamosal involvement remains unclear, to our knowledge there have been no reviews of the nosology and aetiology of synostosis with particular reference to the squamosal suture in the anthropological or clinical literature. Isolated squamosal craniosynostosis may be frequently unreported in clinical settings, and thus case studies on the condition in archaeological contexts may prove valuable for future attempts to identify the frequency and causes of squamosal involvement. This case study also highlights both the potential and challenges of using rare pathological conditions as a tool for positive identification of human remains in historical forensic cases. Copyright © 2007 John Wiley & Sons, Ltd.
Noninvasive prenatal diagnosis of β‐thalassaemia using individual fetal erythroblasts isolated from maternal blood after enrichment
Authors: Kolialexi A. , Vrettou C. , Traeger‐Synodinos J. , Burgemeister R. , Papantoniou N. , Kanavakis E. , Antsaklis A. , Mavrou A.
Published: November 2007

Single nucleated red blood cells (NRBCs) isolated from maternal circulation were used for prenatal diagnosis of β‐thalassaemia. The study included 22 pregnant women in the first trimester, 6 carriers at risk for β‐thalassaemia and 16 noncarriers. Methodology involved enrichment of NRBCs by magnetic cell sorting (MACS) and microdissection of single NRBCs with a laser micromanipulation system. Single‐cell genotyping based on nested real‐time PCR for genotyping β‐globin gene mutations was performed followed by a multiplexed minifingerprinting to confirm the origin of the isolated cells and possible contamination. Two polymorphic markers (D13S314 and GABRB3) facilitated the identification of fetal NRBCs through comparison of allele sizes found in the respective parents. In this study, 224 single NRBCs were detached and transferred into individual PCR tubes. Allele amplification in at least one microsatellite marker was achieved in 128/224 cells.

Minifingerprinting analysis showed that 22 cells were fetal, 26 maternal and 80 were noninformative due to ADO or homozygosity. In 6 NRBCs the β‐globin gene was amplified and in 2, coming from the same pregnancy, only the paternal mutation was detected. The low PCR success when genotyping isolated NRBCs was possibly due to the poor quality of fetal NRBCs and the relatively large size of the β‐globin gene product. Copyright © 2007 John Wiley & Sons, Ltd.
Prevalence of purchase of antihypertensive and serum lipid‐reducing drugs in Sweden—individual data from national registers
Authors: Silwer Louise , Lundborg Cecilia Stålsby , Petzold Max
Published: November 2007

Purpose

To determine the prevalence of purchase of prescribed antihypertensive and/or serum lipid‐reducing pharmaceutical preparations among different age groups, from the age of 45, in the Swedish population. Further, to calculate the percentage of the population, from the age of 60, who purchased these pharmaceuticals without having had a circulatory diagnosis in the Hospital Discharge Register the last 7 years, or having purchased nitrate vasodilators, as an attempt to estimate the proportion of primary preventive treatments.

Methods

A cross‐sectional study, of individual data on prescriptions for antihypertensives (C02–C03, C07–C09) and serum lipid‐reducing agents (C10), dispensed from July to December 2005 for the Swedish population. Data were obtained from the new Swedish Prescribed Drugs Register. The data were related to population statistics, and linked to data on diagnoses of cardiovascular disease (I00–I99), from the Swedish Hospital Discharge Register 1998–2004. Data on individuals with purchase of antihypertensive or serum lipid‐reducing agents, but without a diagnosis of cardiovascular disease, were also linked to purchase of nitrate vasodilators (C01D).

Results

Among Swedes of 60 years and above, 53% purchased antihypertensive or serum lipid‐reducing pharmaceuticals, and 30% purchased the pharmaceuticals without having been hospitalized for a coronary or cerebrovascular event during the previous 7 years, or having purchased prescribed nitrate vasodilators during 6 months.

Conclusion

Over half of the Swedish senior population purchased prescribed antihypertensive or serum lipid‐reducing drugs during 6 months in 2005. The magnitude of the prevalence points to the importance of intensified follow‐up of both adverse effects and of effectiveness of these drugs. Copyright © 2007 John Wiley & Sons, Ltd.
A novel tandem affinity purification strategy for the efficient isolation and characterisation of native protein complexes
Authors: Gloeckner Christian Johannes , Boldt Karsten , Schumacher Annette , Roepman Ronald , Ueffing Marius
Published: November 2007

Isolation and dissection of native multiprotein complexes is a central theme in functional genomics. The development of the tandem affinity purification (TAP) tag has enabled an efficient and large‐scale purification of native protein complexes. However, the TAP tag features a size of 21 kDa and requires time consuming cleavage. By combining a tandem Strep‐tag II with a FLAG‐tag we were able to reduce the size of the TAP (SF‐TAP) tag to 4.6 kDa. Both moieties have a medium affinity and avidity to their immobilised binding partners. This allows the elution of SF‐tagged proteins under native conditions using desthiobiotin in the first step and the FLAG octapeptide in the second step. The SF‐TAP protocol represents an efficient, fast and straightforward purification of protein complexes from mammalian cells within 2.5 h. The power of this novel method is demonstrated by the purification of Raf associated protein complexes from HEK293 cells and subsequent analysis of their protein interaction network by dissection of interaction patterns from the Raf binding partners MEK1 and 14‐3‐3.
A doubly responsive AB diblock copolymer: RAFT synthesis and aqueous solution properties of poly (N‐isopropylacrylamide‐block‐4‐vinylbenzoic acid)
Authors: Lowe Andrew B. , Torres Marry , Wang Ran
Published: November 2007

We describe herein the synthesis and self‐assembly characteristics of a doubly responsive AB diblock copolymer comprised of N‐isopropylacrylamide (NIPAM) and 4‐vinylbenzoic acid (VBZ). The AB diblock copolymer was prepared via reversible addition‐fragmentation chain transfer (RAFT) radical polymerization in DMF employing a trithiocarbonate‐based RAFT agent. PolyNIPAM was employed as the macroRAFT agent. The NIPAM homopolymerization was shown to possess all the characteristics of a controlled process, and the blocking with VBZ was judged, by size exclusion chromatography, to be essentially quantitative. The NIPAM‐VBZ block copolymer was subsequently demonstrated to be able to form normal and inverse micelles in the same aqueous solution by taking advantage of the stimuli responsive characteristics of both building blocks. Specifically, and as judged by NMR spectroscopy and dynamic light scattering, raising the temperature to 40 °C (above the lower critical solution temperature of the NIPAM block), while at pH 12 results in supramolecular self‐assembly to yield nanosized species that are composed of a hydrophobic NIPAM core stabilized by a hydrophilic VBZ corona. Conversely, lowering the solution pH to 2.0 at ambient temperature results in the formation of aggregates in which the VBZ block is now hydrophobic and in the core, stabilized by the hydrophilic NIPAM block. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5864–5871, 2007
Magnetic poly(N‐isopropylacrylamide) microspheres by dispersion and inverse emulsion polymerization
Authors: Macková Hana , Králová Daniela , Horák Daniel
Published: November 2007

The aim of this study was to develop novel thermally responsive polymer microspheres with magnetic properties. Dispersion and inverse emulsion copolymerization of N‐isopropylacrylamide (NIPAAm) and N,N′‐methylenebisacrylamide (MBAAm) was investigated in the presence of γ‐Fe2O3 nanoparticles. The resulting microspheres were characterized in terms of morphology, size, polydispersity, iron content, and temperature‐dependent swelling using optical microscopy, transmission electron microscopy, scanning electron microscopy, QELS, and AAS. The effects of several variables, such as the concentration of γ‐Fe2O3, MBAAm crosslinking agent, Span 80 surfactant, 2,2′‐azobis(2‐methyloctanenitrile) (AMON) initiator, and polymerization temperature on the properties of the microspheres were studied. Swelling and thermoresponsive behavior of the microspheres containing γ‐Fe2O3 nanoparticles were also investigated. The microspheres contained about 8 wt % of iron. The presence of magnetic nanoparticles and their concentration changes did not have any significant effect on the temperature sensitivity of the composites. The particles gradually shrink into an increasingly collapsed state when the temperature is raised to 40 °C since the increase in temperature weakens the hydration and PNIPAAm chains gradually become more hydrophobic, which leads to the collapse of the particles. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5884–5898, 2007
Acyl chloride‐facilitated condensation polymerization for the synthesis of heat‐sensitive poly(anhydride‐ester)s
Authors: Qian Haitao , Mathiowitz Edith
Published: November 2007

We succeeded in developing the acyl chloride‐facilitated condensation polymerization method for the synthesis of new poly(anhydride‐ester)s with aromatic side groups, which cannot be polymerized by the classic melt condensation polymerization method. Using chlorinated and acylated carboxylic acids as the intermediates, the polymerization was carried out at low temperatures of 120 or 135 °C to yield pure poly(anhydride‐ester)s of molecular weights as high as 1.55 × 105 with minimal side‐reactions. A homogeneous route of preparation was developed and optimized, using butyric anhydride as the acylating reagent and oxalyl chloride as the chlorinating reagent. A comparison of the mechanisms of the classic method and the new method indicates that the effects of transacylation—cyclization and oligomer formation—were greatly reduced due to the high reactivity of carboxylic acid chloride and the steric effect of bulky acyl groups. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5899–5915, 2007
Synthesis of crosslinkable fluorinated polyesters for optical waveguide devices
Authors: Fei Xu , Hu Juan , Zhang Haiming , Sha Pengyu , Piao Jicheng , Cui Zhanchen , Zhang Daming
Published: November 2007

A series of novel crosslinkable, highly fluorinated polyesters were synthesized by copolycondensation reactions of terephthaloyl chloride with 4, 4′‐(hexafluoroisopropy‐lidene)‐diphenol and 2,2,3,3,4,4,5,5,6,6,7,7‐dodecafluoro‐octane‐1,8‐diol, followed by reaction with 2‐hydroxyethyl methacrylate. The resulting polyesters with the molecular weights (Mn: 12,100–20,000 g mol−1) and polydispersities (1.49–2.25) were useful for the fabrication of polymer optical devices because of their good solubility in common organic solvent and the processable flexibility. The ratios of the components of the polyesters were characterized by FTIR and NMR. The polyesters had high glass transition temperature (Tg,: up to 170 °C) and good thermal stabilities (Td: up to 470 °C). The refractive index of the polyester film was tuned and controlled in the range of 1.447–1.576 at 1550 nm by monitoring the component fractions during the preparation procedures. Low‐loss optical waveguides were fabricated from the resulting polyesters and the propagation loss of the channel waveguides was measured to be around 0.56 dB/cm at 1550 nm. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5923–5931, 2007
Low potential electrochemical polymerization of diphenyl ether and characterization of its polymers
Authors: Xu Jingkun , Wan Liang , Li Yuzhen , Liu Houting , Pu Shouzhi , Shen Liang
Published: November 2007

High‐quality poly(diphenyl ether) (PDPE) films with electrical conductivity of 4.4 × 10−1 S cm−1 were synthesized electrochemically by direct anodic oxidation of diphenyl ether (DPE) in boron trifluoride diethyl etherate (BFEE) containing 5% concentrated sulfuric acid (SA) (by volume). The oxidation potential onset of DPE in pure BFEE was measured to be only 1.37 V versus a saturated calomel electrode (SCE), which was much lower than that determined in acetonitrile + 0.1 mol L−1 tetrabutylammonium tetrafluoroborate (1.98 V vs. SCE). The addition of SA to BFEE can further decrease the oxidation potential onset of the monomer to 1.18 V versus SCE in the mixed electrolyte of BFEE + 5% SA. PDPE films obtained from this medium showed good redox activity and stability even in concentrated SA. Dedoped PDPE films were partly soluble in the strong polar organic solvent dimethyl sulfoxide. Fluorescent spectral studies indicated that soluble PDPE was a good blue‐light emitter with a quantum yield of 0.30. Infrared spectroscopy and quantum chemistry calculations indicated that the electropolymerization of DPE occurred mainly at C4 and C4′. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5932–5941, 2007
Preparation of temperature‐responsive polymer gels physically immobilizing core‐shell type bioconjugates
Authors: Harada Atsushi , Johnin Kunio , Kawamura Akifumi , Kono Kenji
Published: November 2007

Poly(N‐isopropylacrylamide) (PNIPAAm) gels are temperature‐responsive polymer gels; and were prepared by redox polymerization of N‐isopropylacrylamide in the presence of N,N′‐methylenebisacrylamide as a crosslinking reagent and core‐shell type bioconjugates, which were core‐crosslinked polyion complex micelles formed from the mixture of bovine pancreas trypsin and poly(ethylene glycol)‐block‐poly(α,β‐aspartic acid). The phase transition temperature of PNIPAAm gels was no change with physically immobilization of bioconjugates. Also, the enzymatic activity of bioconjugates was essentially maintained even in PNIPAAm gels, although enzymatic reaction rate was apparently controlled by temperature, i.e., by the degree of swelling of PNIPAAm gels. Further, the control of enzymatic reaction synchronizing the phase transition of PNIPAAm gels immobilized bioconjugates. PNIPAAm gels could immobilize core‐shell type bioconjugates, and were successfully prepared without interfering with the properties of temperature‐responsive polymer gels and the bionanoreactor. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5942–5948, 2007
ABA‐type liquid crystalline triblock copolymers via nitroxide‐mediated radical polymerization: Design, synthesis, and morphologies
Authors: Gao Long‐Cheng , Pan Qi‐Wei , Wang Chao , Yi Yi , Chen Xiao‐Fang , Fan Xing‐He , Zhou Qi‐Feng
Published: November 2007

We have designed and synthesized rod–coil–rod triblock copolymers of controlled molecular weight by two‐step nitroxide‐mediated radical polymerization, where the rod part consists of “mesogen‐jacketed liquid crystalline polymer” (MJLCP). The MJLCP segment examined in our studies is poly{2,5‐bis[(4‐methoxyphenyl)oxycarbonyl]styrene} (MPCS) while the coil part is polyisoprene (PI). Characterization of the triblock copolymers by GPC, 1H and 13C NMR spectroscopies, TGA, DSC confirmed that the triblock copolymers were comprised of microphase‐separated low Tg amorphous PI and high Tg PMPCS blocks. Analysis of POM and 1D, 2D‐WAXD demonstrated that the triblock copolymers formed nematic liquid crystal phase. Morphological studies using TEM indicated the sample formed lamellar structure. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5949–5956, 2007
Pressure relaxation of polystyrene and its comparison to the shear response
Authors: Meng Yan , Simon Sindee L.
Published: November 2007

Isothermal pressure relaxation as a function of temperature in two pressure ranges has been measured for polystyrene using a self‐built pressurizable dilatometer. A master curve for pressure relaxation in each pressure regime is obtained based on the time–temperature superposition principle, and time–pressure superposition of the two master curves is found to be applicable when the master curves are referenced to their pressure‐dependent Tg. The pressure relaxation master curves, the shift factors, and retardation spectra obtained from these curves are compared with those obtained from shear creep compliance measurements for the same material. The shift factors for the bulk and shear responses have the same temperature dependence, and the retardation spectra overlap at short times. Our results suggest that the bulk and shear response have similar molecular origin, but that long‐time chain mechanisms available to shear are lost in the bulk response. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 3375–3385, 2007
Colloid Probe AFM and XPS Study of Time‐Dependent Aging of Amine Plasma Polymer Coatings in Aqueous Media
Authors: Tarasova Anna , Hamilton‐Brown Paul , Gengenbach Thomas , Griesser Hans J. , Meagher Laurence
Published: November 2007

Effects of surface oxidation on the properties of amine plasma polymer (pp) films in aqueous media have not been widely studied, despite their use to control bio‐interfacial properties. Changes in the surface composition of allylamine and heptylamine pp films, on water exposure, were followed by XPS. The surface potential was monitored via AFM measurements and comparison to DLVO theory. Analysis of XPS data implied high initial oxidation rates (rapid quenching of surface radicals). Oxidation of the pp films followed evolution of carbon‐based rather than nitrogen‐based species. Analysis of AFM force data showed changes in the sign of the surface potential with aging from positive to negative. Implications, for example for surface immobilization of molecules in aqueous environments, are also discussed.

magnified image
Allylamine Plasma Polymer Coatings of Interior Surfaces in Small Trench Structures
Authors: Besch Wilfried , Foest Rüdiger , Schröder Karsten , Ohl Andreas
Published: November 2007

The modification of interior surfaces in small trench structures was studied for plasma polymerization processes. Pulsed AAm microwave plasmas were applied to deposit thin films at varied applied microwave powers. Specially designed test specimens served as substrates to investigate trenches with AR from 2 to 10. Thin films coated on external and interior surfaces were analyzed with FT‐IR spectroscopy and XPS measurements. Dense films with similar morphology are observed in all locations. Chemical composition does neither depend on AR nor on depth. In conclusion, this type of AAm plasma polymer deposition is useful for conformal coating of deep trenches with high AR.

magnified image
Proteomic analysis of protein expression changes in a model of gliomagenesis
Authors: McBee Joshua K. , Yu Li‐Rong , Kinoshita Yoshito , Uo Takuma , Beyer Richard P. , Veenstra Timothy D. , Morrison Richard S.
Published: November 2007

Loss of p53 function is a common event in a variety of human cancers including tumors of glial origin. Using an in vitro mouse model of malignant astrocyte transformation, three cleavable isotope coded affinity tag (cICAT) experiments were performed comparing cultured wild‐type astrocytes and two p53−/− astrocyte cultures before and after malignant transformation. We identified and quantitated an average of 1366 proteins per experiment and demonstrated that the protein quantitation ratios in each individual cICAT experiment correlated well to ratios determined in the other two studies. These data were further supported by microarray analysis which also correlated to changes in protein expression. The results showed significant changes in protein expression in association with malignant transformation. Proteins overexpressed in malignant astrocytes were typically involved in ribosome biogenesis/protein synthesis and DNA replication, while underexpressed proteins were generally associated with the regulation of cell cycle checkpoint control, tumor suppression, and apoptosis. Among the significantly up‐regulated proteins and transcripts in malignant mouse astrocytes were members of the minichromosome maintenance (MCM) family. Western blot analysis verified increased expression of MCM proteins in malignant human astrocytoma cell lines, which had not previously been described. These results demonstrate the usefulness of the cICAT approach for comparing differences in protein expression profiles between normal and malignant cells.
Proteomics of brain synapses and molecular dissection of synaptic subdomains
Authors: Li Ka Wan , Smit August B.
Published: November 2007

Synapses form the nuts and bolts of the brain. Synaptic transmission involves an intricate network of synaptic proteins that forms the molecular machinery underlying transmitter release, activation of transmitter receptors, and signal transduction cascades. It is generally believed that neuronal activity‐dependent change of synaptic efficacy is at the basis of learning and memory and is encoded by sequential molecular events at the synapse. In the past 2–3 years, a number of proteomics studies have been performed on synaptic subdomains, including synaptic vesicles, postsynaptic density, synaptic lipid raft, synapse protein complexes, as well as on synaptic protein PTMs, notably phosphorylation. The activity‐dependent dynamics of protein constituents of the synapse are starting to be examined by quantitative proteomics. It is anticipated that these analyses will yield novel insights into the organization of the synapse, and will generate testable hypotheses of synapse function and regulation both in health and disease.
The confirmation of the denatured structure of pyrrolidone carboxyl peptidase under nondenaturing conditions: Difference in helix propensity of two synthetic peptides with single amino acid substitution
Authors: Umezaki Taro , Iimura Satoshi , Noda Yasuo , Segawa Shin‐ichi , Yutani Katsuhide
Published: November 2007

In the denatured state (D1 state) of cystein‐free pyrrolidone carboxyl peptidase (PCP‐0SH) from Pyrococcus furiosus, a hyperthermophile under nondenaturing conditions, a fairly stable α‐helix (α6‐helix) has been determined from H/D exchange‐NMR experiments. On the other hand, the α6‐helix region of the proline‐mutant at position 199 (A199P) was unstructured in the D1 state unlike that of the wild‐type PCP‐0SH, although the folded conformations of both proteins were almost identical to each other. This finding has been deduced from the information regarding the remaining amide hydrogens in the HSQC spectra after H/D exchanges in the D1 state. To confirm this inference, we examined the helical propensities of two synthetic peptides from their NMR structural analysis in the presence of trifluoroethanol (TFE). One is an 18‐residue peptide called the wild‐type H6‐peptide corresponding to the α6‐helix (from Ser188 to Glu205) of the wild‐type PCP‐0SH, and the other is the mutant H6‐peptide corresponding to the α6‐helix region of A199P. The NOE‐contact information obtained from the 2D‐1H‐NOESY spectra measured for both peptides in the presence of 30% TFE clearly demonstrated that the wild‐type H6‐peptide had a high helical propensity, but the mutant H6‐peptide was almost totally unstructured. The TFE‐induced helical propensities for these peptide fragments confirmed the conclusions deduced from the H/D exchange data measured in the D1 states of two proteins. Proteins 2008. © 2007 Wiley‐Liss, Inc.
Role of the IXI/V motif in oligomer assembly and function of StHsp14.0, a small heat shock protein from the acidothermophilic archaeon, Sulfolobus tokodaii strain 7
Authors: Saji Hitoshi , Iizuka Ryo , Yoshida Takao , Abe Tetsuya , Kidokoro Shun‐ichi , Ishii Noriyuki , Yohda Masafumi
Published: November 2007

Small heat shock proteins (sHsps) are one of the most ubiquitous molecular chaperones. They are grouped together based on a conserved domain, the α‐crystallin domain. Generally, sHsps exist as oligomers of 9–40 subunits, and the oligomers undergo reversible temperature‐dependent dissociation into smaller species as dimers, which interact with denaturing substrate proteins. Previous studies have shown that the C‐terminal region, especially the consensus IXI/V motif, is responsible for oligomer assembly. In this study, we examined deletions or mutations in the C‐terminal region on the oligomer assembly and function of StHsp14.0, an sHsp from an acidothermophilic archaeon, Sulfolobus tokodaii strain 7. Mutated StHsp14.0 with C‐terminal deletion or replacement of IIe residues in the IXI/V motif to Ala, Ser, or Phe residues could not form large oligomers and lost chaperone activity. StHsp14.0WKW, whose Ile residues in the IXI/V motif are changed to Trp, existed as an oligomer like that of the wild type. However, it dissociates to small oligomers and exhibits chaperone activity at relatively lowered temperature. Replacement of two Ile residues in the motif to relatively small residues, Ala or Ser, also resulted in the change of β‐sheet rich secondary structure and decrease of hydrophobicity. Interestingly, StHsp14.0 mutant with amino acid replacements to Phe kept almost the same secondary structure and relatively high hydrophobicity despite that it could not form an oligomeric structure. The results show that hydrophobicity and size of the amino acids in the IXI/V motif in the C‐terminal region are responsible not only for assembly of the oligomer but also for the maintenance of β‐sheet rich secondary structure and hydrophobicity, which are important for the function of sHsp. Proteins 2008. © 2007 Wiley‐Liss, Inc.
Understanding the structural and functional differences between mouse thyrotropin‐releasing hormone receptors 1 and 2
Authors: Deflorian Francesca , Engel Stanislav , Colson Anny‐Odile , Raaka Bruce M. , Gershengorn Marvin C. , Costanzi Stefano
Published: November 2007

Multiple computational methods have been employed in a comparative study of thyrotropin‐releasing hormone receptors 1 and 2 (TRH‐R1 and TRH‐R2) to explore the structural bases for the different functional properties of these G protein‐coupled receptors. Three‐dimensional models of both murine TRH receptors have been built and optimized by means of homology modeling based on the crystal structure of bovine rhodopsin, molecular dynamics simulations, and energy minimizations in a membrane‐aqueous environment. The comparison between the two models showed a correlation between the higher flexibility and higher basal activity of TRH‐R2 versus the lesser flexibility and lower basal activity of TRH‐R1 and supported the involvement of the highly conserved W6.48 in the signaling process. A correlation between the level of basal activity and conformational changes of TM5 was detected also. Comparison between models of the wild type receptors and their W6.48A mutants, which have reversed basal activities compared with their respective wild types, further supported these correlations. A flexible molecular docking procedure revealed that TRH establishes a direct interaction with W6.48 in TRH‐R2 but not in TRH‐R1. We designed and performed new mutagenesis experiments that strongly supported these observations. Proteins 2008; 71:783–794. Published 2007 Wiley‐Liss, Inc.