bluuebunny/crossref_metadata_2025 huggingface dataset:
WWOX hypomorphic mice display a higher incidence of B‐cell lymphomas and develop testicular atrophy
Authors: Ludes‐Meyers John H. , Kil Hyunsuk , Nuñez Maria I. , Conti Claudio J. , Parker‐Thornburg Jan , Bedford Mark T. , Aldaz C. Marcelo
Published: September 2007

WWOX is a putative tumor suppressor gene encoded within common chromosomal fragile site region FRA16D, in chromosome band 16q23. Multiple studies have demonstrated that WWOX expression is often reduced or lost in various tumor types. WWOX tumor suppressor activity was suggested by re‐expressing WWOX in breast, ovarian, and lung tumor cell lines leading to tumor growth inhibition in vivo. To determine whether loss of Wwox gene expression has a role in tumorigenesis, we generated a mouse strain containing a Wwox gene mutated by a gene‐trap vector. Homozygous Wwox gene‐trap mice (Wwoxgt/gt) had no detectable Wwox protein in most tissues examined, although, a low level could be detected in a minority of tissues. Because of these observations, we concluded that these mice are Wwox hypomorphs. Remarkably, Wwox hypomorphic mice are viable in contrast to the recently reported postnatal lethality of Wwox knockout mice. Testes from Wwoxgt/gt males had high numbers of atrophic seminiferous tubules and reduced fertility when compared with wild‐type counterparts. We observed that the Wwoxgt/gt mice had a significantly shorter lifespan, and female hypomorphs had a higher incidence of spontaneous B‐cell lymphomas. In conclusion, we describe a novel Wwox hypomorphic mouse model that overcomes postnatal lethality that was recently observed in Wwox knockout mice. Therefore, tumorigenesis studies using this model more closely recapitulates the loss of WWOX expression observed in human cancers. Importantly, our observation that Wwox hypomorphs had an increased incidence of B‐cell lymphomas supports a role of Wwox as a tumor suppressor. © 2007 Wiley‐Liss, Inc.
Resident microglia die and infiltrated neutrophils and monocytes become major inflammatory cells in lipopolysaccharide‐injected brain
Authors: Ji Kyung‐Ae , Yang Myung‐Soon , Jeong Hey‐Kyeong , Min Kyoung‐Jin , Kang Seung‐Hee , Jou Ilo , Joe Eun‐Hye
Published: September 2007

Generally, it has been accepted that microglia play important roles in brain inflammation. However, recently several studies suggested possible infiltration of blood neutrophils and monocytes into the brain. To understand contribution of microglia and blood inflammatory cells to brain inflammation, the behavior of microglia, neutrophils, and monocytes was investigated in LPS (lipopolysaccharide)‐injected substantia nigra pars compacta, cortex, and hippocampus of normal and/or leukopenic rats using specific markers of neutrophils (myeloperoxidase, MPO), and microglia and monocytes (ionized calcium binding adaptor molecule‐1, Iba‐1), as well as a general marker for these inflammatory cells (CD11b). CD11b‐immunopositive (CD11b+) cells and Iba‐1+ cells displayed similar behavior in intact and LPS‐injected brain at 6 h after the injection. Interestingly, however, CD11b+ cells and Iba‐1+ cells displayed significantly different behavior at 12 h: Iba‐1+ cells disappeared while CD11b+ cells became round in shape. We found that CD11b/Iba‐1‐double positive (CD11b+/Iba‐1+) ramified microglia died within 6 h after LPS injection. The round CD11b+ cells detected at 12 h were MPO+. These CD11b+/MPO+ cells were not found in leukopenic rats, suggestive of neutrophil infiltration. MPO+ neutrophils expressed inducible nitric oxide synthase, interleukin‐1β, cyclooxygenase‐2, and monocyte chemoattractant protein‐1, but died within 18 h. CD11b+ cells detected at 24 h appeared to be infiltrated monocytes, since these cells were once labeled with Iba‐1 and were not found in leukopenic rats. Furthermore, transplanted monocytes were detectable in LPS‐injected brain. These results suggest that at least a part of neutrophils and monocytes could have been misinterpreted as activated microglia in inflamed brain. © 2007 Wiley‐Liss, Inc.
Differentiation of primary adult microglia alters their response to TLR8‐mediated activation but not their capacity as APC
Authors: Zuiderwijk‐Sick Ella A. , van der Putten Céline , Bsibsi Malika , Deuzing Ilona P. , de Boer Willem , Persoon‐Deen Carla , Kondova Ivanela , Boven Leonie A. , van Noort Johannes M. , 't Hart Bert A. , Amor Sandra , Bajramovic Jeffrey J.
Published: September 2007

Activated microglia are found in a variety of neuroinflammatory disorders where they have attributed roles as effector as well as antigen‐presenting cells (APC). Critical determinants for the multifaceted role of microglia are the differentiation potential of microglia and their mode of activation. In this study, we have investigated the effects of M‐CSF and GM‐CSF‐mediated differentiation of adult primate microglia on their cellular phenotype, antigen presentation, and phagocytic function as well as on Toll‐like receptor (TLR)‐mediated responses. We show that although cell morphology and expression levels of activation markers were markedly different, differentiation with either factor yielded microglia that phenotypically and functionally resemble macrophages. Both M‐CSF and GM‐CSF‐differentiated microglia were responsive to TLR1/2, 2, 3, 4, 5, 6/2, and 8‐mediated activation, but not to TLR7 or 9‐mediated activation. Intriguingly, M‐CSF‐differentiated microglia expressed higher levels of TLR8‐encoding mRNA and protein, and produced larger amounts of proinflammatory cytokines in response to TLR8‐mediated activation as compared to GM‐CSF‐differentiated microglia. While differentiation of adult microglia by growth factors that can be produced endogenously in the central nervous system is thus unlikely to change their APC function, it can alter their innate responses to infectious stimuli such as ssRNA viruses. Resident primate microglia may thereby help shape rather than initiate adaptive immune responses. © 2007 Wiley‐Liss, Inc.
Developmental expression of FMRP in the astrocyte lineage: Implications for fragile X syndrome
Authors: Pacey Laura K. K. , Doering Laurie C.
Published: September 2007

One of the most common causes of mental retardation in humans, Fragile X syndrome, results from the absence of FMRP, the protein product of the FMR1 gene. In the nervous system, expression of FMRP has been thought to be confined mainly to neurons as little research has examined FMRP expression in non‐neuronal lineages. We present evidence that, in addition to neuronal expression, FMRP is expressed in developing CNS glial cells in vitro and in vivo. The neurosphere assay was used to establish cultures of stem and progenitor cells from the brains of wildtype and FMRP knockout (B6.129.FMR1/FvBn) mouse pups. When the neurospheres were differentiated in vitro, ∼50% of the FMRP positive cells also expressed GFAP. Immunocytochemical studies of the embryonic and postnatal mouse brain revealed coexpression of FMRP and GFAP in the developing hippocampus. Prominent coexpression was also observed in ependymal cells surrounding the third ventricle and astrocytes of the glia limitans. No double‐labeled cells were evident in the brains of young adult mice. Cells coexpressing FMRP and the oligodendrocyte precursor marker NG2 were also identified in the hippocampus and corpus callosum of the early postnatal brain. Our results suggest that FMRP is expressed in cells of non‐neuronal lineage(s) during development. This represents potential involvement of glial cells in the neural development of fragile X syndrome. © 2007 Wiley‐Liss, Inc.
Dulxanthone A induces cell cycle arrest and apoptosis via up‐regulation of p53 through mitochondrial pathway in HepG2 cells
Authors: Tian Ze , Shen Jie , Moseman Annie P. , Yang Quanli , Yang Junshan , Xiao Peigen , Wu Erxi , Kohane Isaac S.
Published: September 2007

Natural products derived from plants provide a rich source for development of new anticancer drugs. Dulxanthone A was found to be an active cytotoxic component in Garcinia cowa by bioactivity‐directed isolation. Studies to elucidate the cytotoxic mechanisms of dulxanthone A showed that dulxanthone A consistently induced S phase arrest and apoptosis in the most sensitive cell line HepG2. Furthermore, p53 was dramatically up‐regulated, leading to altered expression of downstream proteins upon dulxanthone A treatment. Cell cycle related proteins, such as cyclin A, cyclin B, cyclin E, cdc‐2, p21 and p27 were down‐regulated. Some apoptosis correlated proteins were also altered following the drug treatment. Bcl‐2 family members PUMA was up‐regulated while Bcl‐2 and Bax were down‐regulated. However, the expression ratio of Bax/Bcl‐2 was increased. This resulted in the release of cytochrome C from the mitochondria to the cytosol. Concurrently, Apaf‐1 was stimulated with p53 by dulxanthone A. In result, cytochrome C, Apaf‐1 and procaspase‐9 form an apoptosome, which in turn triggered the activation of caspase‐9, caspase‐3 and downstream caspase substrates. Lamin A/C and PARP were down‐regulated or cleaved, respectively. Moreover, cell cycle arrest and apoptosis in HepG2 cells induced by dulxanthone A were markedly inhibited by siRNA knockdown of p53. In summary, dulxanthone A is an active cytotoxic component of G. cowa. It induces cell cycle arrest at lower concentrations and triggers apoptosis at higher concentrations via up‐regulation of p53 through the intrinsic mitochondrial pathway in HepG2 cells. Dulxanthone A is therefore likely a promising preventive and/or therapeutic agent against Hepatoma. © 2007 Wiley‐Liss, Inc.
A ratings‐based approach to measuring sovereign risk
Authors: Remolona Eli M. , Scatigna Michela , Wu Eliza
Published: September 2007

We propose a new approach to measuring sovereign default risk. We use sovereign credit ratings and historical default rates provided by credit rating agencies to construct a measure of ratings‐implied expected loss. We compare our measure of expected loss from sovereign defaults with stand‐alone credit ratings and also examine its relationship with credit default swap spreads. We show that our measure is more informative for measuring sovereign risk. We re‐examine the fundamental determinants of sovereign risk and find further evidence to support the debt intolerance and original sin explanations for country risk. This study contributes an improved understanding of the value of sovereign credit rating teams in assessing the long‐term country risks accompanying emerging market investments. Copyright © 2007 John Wiley & Sons, Ltd.
The development of maternal self‐esteem
Authors: Farrow C. , Blissett J.
Published: September 2007

Although an important theoretical concept, little is known about the development of maternal self‐esteem. This study explores the significance of maternal cognitions, psychopathological symptoms, and child temperament in the prediction of prenatal and postnatal maternal self‐esteem. During pregnancy 162 women completed measures assessing their unhealthy core beliefs, psychopathological symptoms, and self‐esteem. At 1 year postpartum 87 of these women completed measures assessing their self‐esteem and their child's temperament. Overall maladaptive maternal core beliefs and psychopathological symptoms during pregnancy explained 19% of the variance in prenatal maternal self‐esteem. Forty‐two percent of the variance in maternal self‐esteem at 1 year could be explained by a combination of prenatal maternal self‐esteem, mental health symptoms, maternal core beliefs, and more unsociable infant temperament. Underlying maternal cognitive structures may be important in determining the development of maternal self‐esteem.
Caspase‐cleaved cytokeratin 18 and 20 S proteasome in liver degeneration
Authors: Hetz Hubert , Hoetzenecker Konrad , Hacker Stefan , Faybik Peter , Pollreisz Andreas , Moser Bernhard , Roth Georg , Hoetzenecker Wolfram , Lichtenauer Michael , Klinger Markus , Krenn Claus Georg , Ankersmit Hendrik Jan
Published: September 2007

Apoptosis of epithelial hepatocytes plays a pivotal role in acute as well as in chronic liver diseases. The cleavage of cytokeratin‐18 (CK‐18) by caspases is an early event in the apoptotic process. We therefore sought to investigate serum levels of CK‐18 and 20S proteasome in patients with liver cirrhosis, primary graft dysfunction (PDF), and acute liver failure (ALF), and in healthy volunteers. Enzyme‐linked immunosorbent assay (ELISA) was utilized to measure the concentration of M30, a fragment of CK‐18 cleaved at Asp396 (M30 neoantigen), and the concentration of 20S proteasome. Serum levels of the CK‐18 neoepitope M30 were significantly increased in ALF, primary graft dysfunction, and liver cirrhosis vs. healthy controls (1,993.6±124.7 U/L, 2,238.1±235.9 U/L, and 673.6±86.5 U/L vs. 66.8±29.1 U/L, respectively, P<0.001). Similar results were detected with the evaluation of 20S proteasome (124,014.5±13,235.6 ng/mL, 76,993.2±15,720.1 ng/mL, and 2,395.9±1,098.2 ng/mL vs. 1,074.5±259.4 ng/mL, respectively; P<0.001). Detection of CK‐18 neoepitope M30 and 20S proteasome may represent a novel marker of tracing apoptotic epithelium, respectively mirroring degenerative liver processes in affected patient population. J. Clin. Lab. Anal. 21:277–281, 2007. © 2007 Wiley‐Liss, Inc.
Levels of serum sialic acid and thiobarbituric acid reactive substances in subjects with impaired glucose tolerance and type 2 diabetes mellitus
Authors: Yilmaz Gulsen , Yilmaz Fatma Meric , Aral Yalcin , Yucel Dogan
Published: September 2007

Cardiovascular disease is a common cause of death for diabetic patients. High sialic acid levels (SA) and increased oxidative stress are important factors for cardiovascular diseases. We aimed to research whether SA and thiobarbituric acid reactive substances (TBARS) levels are associated with the degree of the diabetic regulation and investigate if SA and TBARS levels can be controlled with the regulation of the blood glucose levels. A total of 179 subjects were included in the study. Three groups, which were comprised of subjects with type 2 diabetes mellitus (DM) (DM group [DMG], n=149), impaired glucose tolerance (IGT) (IGT group [IGTG], n=15), and normal oral glucose tolerance (NGT) (NGTgroup [NGTG], n=15) were constituted. Glucose, cholesterol, high‐density lipoprotein (HDL) and glycated hemoglobin (HbA1C), SA, and TBARS were measured in the sera of the patients. SA and TBARS levels were significantly increased in subjects with type 2 DM (P<0.001 for both). SA concentrations showed significant correlation with triglycerides (r=0.229; P<0.05), fasting glucose (r=0.508; P<0.01), 2‐hr postprandial glucose (r=0.455; P<0.01), and HbA1C (r=0.467; P<0.01), and there was a positive correlation between TBARS and HbA1C (r=0.251; P<0.01). Diabetic patients were found to have higher risk for inflammation and oxidative stress. The regulation of blood glucose levels may contribute to the decline of both SA and TBARS levels. J. Clin. Lab. Anal. 21:260–264, 2007. © 2007 Wiley‐Liss, Inc.
Determination of leukocyte counts in cerebrospinal fluid with a disposable plastic hemocytometer
Authors: Yamanishi Hachiro , Imai Nobuko , Suehisa Etsuji , Kanakura Yuzuru , Iwatani Yoshinori
Published: September 2007

Manual microscopic cell counting in a Fuchs‐Rosenthal (FR) chamber has been the gold standard for quantification of leukocytes in cerebrospinal fluid (CSF). However, for accurate determination of the number and differentiation of cells by chamber counting, hemocytometers must be prepared carefully and kept clean. Improper fitting of the chamber and coverslip changes the volume of sample introduced into the chamber well. Moreover, because conventional hemocytometers are used repeatedly and are breakable, there is a risk of exposure to potentially infectious material. To address these issues, disposable plastic hemocytometers have been developed. However, the accuracy, precision, and clinical usefulness of disposable chambers for CSF cells counting have not been determined. In the present study, we evaluated use of a disposable plastic counting chamber (C‐Chip DHC‐F01) by comparing its performance with that of an FR chamber for counting of CSF specimens and cell suspensions. Within‐run precision of C‐Chip counting was comparable or superior to that of FR chamber counting, and excellent correlation between cell counts obtained with the C‐Chip chamber and FR chamber was observed. However, C‐Chip chambers that were kept at 4°C yielded significantly low cell counts. The disposable hemocytometer will reduce the risk of exposure to potentially infectious material. However, use of C‐Chip chambers should be avoided in cold environments. J. Clin. Lab. Anal. 21:282–285, 2007. © 2007 Wiley‐Liss, Inc.
NA1/NA2 heterozygote of Fcgr3b is a risk factor for progression of IgA nephropathy in Chinese
Authors: Xu Gaosi , He Qiang , Shou Zhangfei , Wang Huiping , Zhang Xiaohui , Wang Yaomin , Chen Ying , Chen Jianghua
Published: September 2007

Several studies have identified FcgRIIIb (Fcgr3b) polymorphisms that determine susceptibility to autoimmune diseases such as systemic lupus erythematosus and rheumatoid arthritis. The objective of the study was to clarify whether Fcgr3b allele polymorphism influence susceptibility to immunoglobulin A nephropathy (IgAN), clinical features or severity in patients with IgAN. Deoxyribonucleic acid (DNA) fragments were amplified by polymerase chain reaction (PCR) using genomic DNA from 172 unrelated, healthy blood donors and 128 IgAN patients in our Kidney Disease Centre. The present findings showed that Fcgr3b genotype influenced the disease susceptibility and severity of IgAN, although Fcgr3b polymorphism did not affect the age of the disease onset. We found that the genotype frequency of Fcgr3b heterozygote NA1/NA2 in IgAN patients in Chinese significantly higher than that of healthy donors. Furthermore, higher genotype frequency of NA1/NA2 was found also in IgAN patients with glomerulosclerosis or crescent formation than those without it. NA1/NA2 heterozygote of Fcgr3b is a risk factor for progression of IgA nephropathy in Chinese. J. Clin. Lab. Anal. 21:298–302, 2007. © 2007 Wiley‐Liss, Inc.
Development of an ELISA method for detecting immune complexes between tissue‐nonspecific alkaline phosphatase and immunoglobulin G
Authors: Hocchi Kazuo , Ohashi Tatsuya , Miura Toshihide , Sasagawa Kumiko , Sato Yasuhito , Nomura Fumio , Tomonaga Takeshi , Sunaga Masahiko , Kojima Ryo , Katayama Katsuhiro , Kato Toshiyuki , Sato Toyoji , Komoda Tsugikazu , Oda Kimimitsu
Published: September 2007

A convenient method for measuring immune complexes between tissue‐nonspecific alkaline phosphatase (TNSALP) and immunoglobulin G (IgG) (i.e., TNSALP‐IgG) would be highly useful for routine analyses. Here, we identified a surface‐active agent that would dissolve membrane but not dissociate TNSALP‐IgG complexes. Next, we developed an enzyme‐linked immunosorbent assay (ELISA) method for detecting TNSALP‐IgG complexes with two monoclonal antibodies (MoAbs): 3‐29‐3R was coated on assay plates and captured TNSALP‐IgG from a specimen; an horseradish peroxidase (HRP)‐conjugated anti‐human IgG1 then reacted with captured TNSALP‐IgG to form an “immunocomplex sandwich.” The immunocomplex was detected via the absorbance of an HRP substrate, resulting in a semiquantitative assay. The mean absorbance of 0.195 (n=5) measured in sera from healthy donors was designated as an arbitrary unit (AU/mL) of TNSALP‐IgG concentration. The ELISA values of patient sera known to contain TNSALP‐IgG complexes were greater than those of normal sera (normal, 1.86 plusmn; 0.61; patient, 9.30 plusmn; 5.44), and these data were confirmed by electrophoresis. Thus, the ELISA could detect TNSALP‐IgG complexes. The intraassay coefficient of variation (CV) was within 7.4% and analytical recovery was excellent. There was no significant interference from hemolytic, lipemic, or icteric serum. In summary, an ELISA using 3‐29‐3R MoAb and HRP‐conjugated anti‐human IgG1 constitutes a reliable and convenient method for the semiquantitative detection of TNSALP‐IgG complexes in human serum. J. Clin. Lab. Anal. 21:322–329, 2007. © 2007 Wiley‐Liss, Inc.
The average degree of an edge‐chromatic critical graph II
Authors: Woodall Douglas R.
Published: September 2007

A graph G with maximum degree Δ and edge chromatic number $\chi\prime({G}) > \Delta$ is edge‐Δ‐critical if $\chi\prime{(G-e)} = \Delta$ for every edge e of G. It is proved that the average degree of an edge‐Δ‐critical graph is at least ${2\over 3}{(\Delta+1)}$ if $\Delta \geq 2$, at least ${2\over 3}\Delta + 1$ if $\Delta \geq 8$, and at least ${2\over 3}(\Delta + 2)$ if $\Delta \geq 15$. For large Δ, this improves on the best bound previously known, which was roughly ${1\over 2}(\Delta+\sqrt{2\Delta})$. © Wiley Periodicals, Inc. J. Graph Theory 56: 194–218, 2007
Self‐organization versus Watchmaker: ambiguity of molecular recognition and design charts of cellular circuitry
Authors: Kurakin Alexei
Published: September 2007

A large body of experimental evidence indicates that the specific molecular interactions and/or chemical conversions depicted as links in the conventional diagrams of cellular signal transduction and metabolic pathways are inherently probabilistic, ambiguous and context‐dependent. Being the inevitable consequence of the dynamic nature of protein structure in solution, the ambiguity of protein‐mediated interactions and conversions challenges the conceptual adequacy and practical usefulness of the mechanistic assumptions and inferences embodied in the design charts of cellular circuitry. It is argued that the reconceptualization of molecular recognition and cellular organization within the emerging interpretational framework of self‐organization, which is expanded here to include such concepts as bounded stochasticity, evolutionary memory, and adaptive plasticity offers a significantly more adequate representation of experimental reality than conventional mechanistic conceptions do. Importantly, the expanded framework of self‐organization appears to be universal and scale‐invariant, providing conceptual continuity across multiple scales of biological organization, from molecules to societies. This new conceptualization of biological phenomena suggests that such attributes of intelligence as adaptive plasticity, decision‐making, and memory are enforced by evolution at different scales of biological organization and may represent inherent properties of living matter. Copyright © 2007 John Wiley & Sons, Ltd.
Studies of the intermolecular DNA triplexes of C+·GC and T·AT triplets by electrospray ionization Fourier‐transform ion cyclotron resonance mass spectrometry
Authors: Wan Cuihong , Guo Xinhua , Liu Zhiqiang , Liu Shuying
Published: September 2007

Formation and stabilities of four 14‐mer intermolecular DNA triplexes, consisting of third strands with repeating sequence CTCT, CCTT, CTT, or TTT, were studied by electrospray ionization Fourier‐transform ion cyclotron resonance mass spectrometry (ESI‐FTICR‐MS) in the gas phase. The gas‐phase stabilities of the triplexes were compared with their CD spectra and melting behaviors in solution, and parallel correlation between two phases were obtained. In the presence of 20 mM NH4+ (pH 5.5), the formation of the TTT triplex was not detected in both solution and the gas phase. Other triplexes showed the same order, CTCT > CCTT > CTT, of ion abundances in mass spectra and Tm values in solution. The more stable triplexes are those that contained higher percentage of C+·GC triplets and an alternating CT sequence. However, the CCTT with the same C+·GC triplets as the CTCT showed a higher stability than the latter during the gas‐phase dissociation. Furthermore, a biphasic triplex‐to‐duplex‐to‐single transition was detected in the gas phase, while a monophasic triplex‐to‐single dissociation was observed in solution. The present results reveal that hydrogen bonds and electrostatic interactions dominate in the gas phase, while base stacking and hydrophobic interactions dominate in solution to stabilize the triplexes. Moreover, weak acidic conditions (pH 5–6) promote the formation of the parallel triplexes. Copyright © 2007 John Wiley & Sons, Ltd.
Mechanisms of impaired mitochondrial energy metabolism in acute and chronic neurodegenerative disorders
Authors: Soane Lucian , Kahraman Sibel , Kristian Tibor , Fiskum Gary
Published: September 2007

Altered mitochondrial energy metabolism contributes to the pathophysiology of acute brain injury caused by ischemia, trauma, and neurotoxins and by chronic neurodegenerative disorders such as Parkinson's and Huntington's diseases. Although much evidence supports that the electron transport chain dysfunction in these metabolic abnormalities has both genetic and intracellular environmental causes, alternative mechanisms are being explored. These include direct, reversible inhibition of cytochrome oxidase by nitric oxide, release of mitochondrial cytochrome c, oxidative inhibition of mitochondrial matrix dehydrogenases and adenine nucleotide transport, the availability of NAD for dehydrogenase reactions, respiratory uncoupling by activities such as that of the permeability transition pore, and altered mitochondrial structure and intracellular trafficking. This review focuses on the catabolism of neuronal NAD and the release of neuronal mitochondrial NAD as important contributors to metabolic dysfunction. In addition, the relationship between apoptotic signaling cascades and disruption of mitochondrial energy metabolism is considered in light of the fine balance between apoptotic and necrotic neural cell death. © 2007 Wiley‐Liss, Inc.
Late Quaternary speleothem pollen in the British Isles
Authors: Caseldine Christopher J. , McGarry Siobhán F. , Baker Andy , Hawkesworth Chris , Smart Peter L.
Published: September 2007

As with many terrestrial areas, the British Quaternary sequence is characterised by incomplete, fragmentary records, whose correlation is based on stratigraphic or biostratigraphic techniques due to the lack of radiometric ages beyond the ∼40 kyr limit of 14C dating. Speleothems (secondary cave calcite deposits) offer a significant advantage over many sources of palaeoenvironmental information; they can be dated to a high precision and accuracy by uranium‐thorium (238U‐230Th) thermal ionisation and inductively coupled plasma (ICP) mass spectrometry in the time period back to 500 kyr. They may also contain sufficient well‐preserved pollen representative of contemporary vegetation above the cave to allow palaeoenvironmental reconstruction. This study adopts the novel approach of combining pollen and thermal ionisation mass spectrometric (TIMS) U‐Th dating of British speleothems to produce well‐constrained palaeoenvironmental records. We report for the first time precisely dated records of pollen assemblages from speleothems suggesting the presence of thermophilous arboreal species in phases previously considered to have been consistently cool or cold and devoid of trees. Copyright © 2007 John Wiley & Sons, Ltd.
Quaternary tectonics in a passive margin: Marajó Island, northern Brazil
Authors: Rossetti Dilce F. , Góes Ana M. , Valeriano Márcio M. , Miranda Maria Carolina C.
Published: September 2007

Marajó Island is located in a passive continental margin that evolved from rifting associated with the opening of the Equatorial South Atlantic Ocean in the Late Jurassic/Early Cretaceous period. This study, based on remote sensing integrated with sedimentology, as well as subsurface and seismographic data available from the literature, allows discussion of the significance of tectonics during the Quaternary history of marginal basins. Results show that eastern Marajó Island contains channels with evidence of tectonic control. Mapping of straight channels defined four main groups of lineaments (i.e. NNE–SSW, NE–SW, NW–SE and E–W) that parallel main normal and strike‐slip fault zones recorded for the Amazon region. Additionally, sedimentological studies of late Quaternary and Holocene deposits indicate numerous ductile and brittle structures within stratigraphic horizons bounded by undeformed strata, related to seismogenic deformation during or shortly after sediment deposition. This conclusion is consistent with subsurface Bouguer mapping suggestive of eastern Marajó Island being still part of the Marajó graben system, where important fault reactivation is recorded up to the Quaternary. Together with the recognition of several phases of fault reactivation, these data suggest that faults developed in association with rift basins might remain active in passive margins, imposing important control on development of depositional systems. Copyright © 2007 John Wiley & Sons, Ltd.
One step purification of flavanone glycosides from Poncirus trifoliata by centrifugal partition chromatography
Authors: Kim Chul Young , Lee Hee Ju , Lee Mi Kyeong , Ahn Mi‐Jeong , Kim Jinwoong
Published: September 2007

Flavanone glycosides were successfully separated from the crude extract of Poncirus trifoliata by preparative centrifugal partition chromatography with a two‐phase solvent system composed of ethyl acetate–acetonitrile–water (3:2:5, v/v/v). Naringin (50.0 mg), neoponcirin (16.8 mg), and poncirin (71.9 mg) were purified from the 524 mg crude extract in only one step. The purities of the isolated compounds were determined to be over 90% by HPLC analysis and their structures were elucidated by 1H NMR, 13C NMR, and ESI‐MS.
The performance of a fiber optic displacement sensor for different types of probes and targets
Authors: Yasin M , Harun S W , Abdul-Rashid H A , Kusminarto  , Karyono  , Ahmad H
Published: September 2007

A simple fiber optic displacement sensor is presented using a multimode plastic bundled fiber and the intensity modulation technique. The performance of the sensor is compared for different types of probes and targets. The probe with the largest receiving core diameter demonstrates the highest linearity range, and increasing the number of receiving cores increases the sensitivity of the sensor. With a stainless steel target and the concentric bundled fiber with 16 receiving fibers as a probe, the sensitivity of the sensor is found to be 0.0220 mV/μm over 150 to 550 μm range and – 0.0061 mV/μm over 1100 to 2000 μm range. The target with a higher reflectivity shows a higher sensitivity. The linearity range for the front slope is almost similar for all targets tested. However, for the back slope, lower reflectivity objects have a relatively higher linearity range with the highest range of 1600 μm being obtained using plastic and aluminum targets. The simplicity of the design, high degree of sensitivity, dynamic range, non-contact measurement and low cost of the fabrication make it suitable for applications in industries for position control and micro displacement measurement in the hazardous regions.
Fabrication of two-dimensional photonic crystal by soft lithography and measure of superprism phenomena
Authors: Zhang S , Wang Q , Zhang X , Wang Y , Li L , Wang L , Chen J
Published: September 2007

The 2D photonic crystal superprism structures with a triangle array of air holes were designed and fabricated on the polymer slab by soft lithography method. The profile of the molded structures with 450 nm in diameter and 900 nm in lattice constant was examined by SEM. By means of experiment and measurement, the beam propagation angle that can be changed from positive to negative was obtained, when the input incident angle varied from 15° to 11°. And the superprism effect at near-infrared wavelength 1550 nm was demonstrated effectively.
A conditional GIS‐interpolation‐based model for mapping soil‐water erosion processes in Lebanon
Authors: Kheir R. Bou
Published: September 2007

Soil erosion by water is a major cause of landscape degradation in Mediterranean environments, including Lebanon. This paper proposes a conditional decision‐rule interpolation‐based model to predict the distribution of multiple erosion processes (i.e. sheet, mass and linear) in a representative area of Lebanon from the measured erosion signs in the field (root exposure, earth pillars, soil etching and drift and linear channels). First, erosion proxies were derived from the structural OASIS classification of Landsat thematic mapper (TM) imageries combined with the addition of several thematic erosion maps (slope gradient, aspect and curvature, drainage density, vegetal cover, soil infiltration and erodibility and rock infiltration/movement) under a geographic information systems (GIS) environment. Second, erosion signs were measured in the field, and interpolated by the statistical moments (means and variance) in the defined erosion proxies, thus producing quantitative erosion maps (t ha−1) at a scale of 1:100 000. Seven decision rules were then generated and applied on these maps in order to produce the overall decisive erosion map reflecting all existing erosion processes, that is, equality (ER), dominance (DOR), bimodality (BR), masking (MR), aggravating (AR), dependence (DER) and independence (IR). The produced erosion maps are divided into seven classes ranging between 0 and more than 1·8 t ha−1 for sheet erosion, and 0 and more than 10·5 t ha−1 for mass and linear erosion. They are fairly matching with coincidences values equal to 43 per cent (sheet/linear), 48 per cent (sheet/mass) and 49 per cent (linear/mass). The overall accuracies of these maps were estimated to be 76 per cent (sheet erosion), 78 per cent (mass erosion) and 78·5 per cent (linear erosion). The overall decisive erosion map with 15 classes corresponds well to land management needs. The model used is relatively simple, and may also be applied to other areas. It is particularly useful when GIS database on factors influencing erosion is limited. Copyright © 2007 John Wiley & Sons, Ltd.
Macromol. Rapid Commun. 18–19/2007
Authors: Weber Jens , Su Qi , Antonietti Markus , Thomas Arne
Published: September 2007

Cover: Highly contorted polyimides and polyamides based on spirobifluorene derivatives have been prepared. Depending on the overall chain rigidity, the polymers show intrinsic microporosity and enhanced solubility in solvents like chloroform or THF. Further details can be found in the article by J. Weber, Q. Su, M. Antonietti, and A. Thomas* on page 1871.
Acute sensory ataxic neuropathy with antibodies to GD1b and GQ1b gangliosides and prompt recovery
Authors: Notturno Francesca , Caporale Christina M. , Uncini Antonino
Published: September 2007

Three patients developed acute pure sensory ataxic neuropathy. Two of the three patients had a recent Campylobacter jejuni infection. Patient 1 had monospecific IgG anti‐GD1b. Patients 2 and 3 had cross‐reactive IgG anti‐GQ1b and anti‐GD1b and patient 2 also had IgG anti‐GT1a. Motor nerve conduction studies were completely normal. Sensory conductions showed reduced amplitude or absent sensory nerve action potentials with normal or slightly slowed conduction velocities. In patient 2, serial electrophysiological studies showed reappearance and improvement of sensory nerve potential amplitudes in 4 weeks. All patients recovered completely in 2 months and sensory potential amplitudes normalized in 3–5 months. Our findings: (1) confirm the existence of a pure acute sensory ataxic neuropathy with cross‐reactive IgG anti‐GQ1b and anti‐GD1b as a variant of Guillain–Barré syndrome; (2) expand the clinical presentation of Guillain–Barré syndrome after C. jejuni infection and suggest that molecular mimicry is at the basis of acute sensory ataxic neuropathy; and (3) indicate that, in acute sensory ataxic neuropathy with prompt recovery, the site of the lesion is not in the primary sensory neurons and the pathophysiological mechanism may be functional in nature. Muscle Nerve, 2007
The immunocompetence of Schwann cells
Authors: Meyer Zu Hörste Gerd , Hu Wei , Hartung Hans‐Peter , Lehmann Helmar C. , Kieseier Bernd C.
Published: September 2007

Schwann cells are the myelinating glial cells of the peripheral nervous system that support and ensheath axons with myelin to enable rapid saltatory signal propagation in the axon. Immunocompetence, however, has only recently been recognized as an important feature of Schwann cells. An autoimmune response against components of the peripheral nervous system triggers disabling inflammatory neuropathies in patients and corresponding animal models. The immune system participates in nerve damage and disease manifestation even in non‐inflammatory hereditary neuropathies. A growing body of evidence suggests that Schwann cells may modulate local immune responses by recognizing and presenting antigens and may also influence and terminate nerve inflammation by secreting cytokines. This review summarizes current knowledge on the interaction of Schwann cells with the immune system, which is involved in diseases of the peripheral nervous system. Muscle Nerve, 2007
Quasi‐static crack propagation in plane and plate structures using set‐valued traction‐separation laws
Authors: Areias Pedro M. A. , Rabczuk Timon
Published: September 2007

We introduce a numerical technique to model set‐valued traction‐separation laws in plate bending and also plane crack propagation problems. By using of recent developments in thin (Kirchhoff–Love) shell models and the extended finite element method, a complete and accurate algorithm for the cohesive law is presented and is used to determine the crack path. The cohesive law includes softening and unloading to origin, adhesion and contact. Pure debonding and contact are obtained as particular (degenerate) cases. A smooth root‐finding algorithm (based on the trust‐region method) is adopted. A step‐driven algorithm is described with a smoothed law which can be made arbitrarily close to the exact non‐smooth law. In the examples shown the results were found to be step‐size insensitive and accurate. In addition, the method provides the crack advance law, extracted from the cohesive law and the absence of stress singularity at the tip. Copyright © 2007 John Wiley & Sons, Ltd.
The construct validity of three entry level personality inventories used in the UK: a cautionary case study
Authors: Anderson Neil , Ones Deniz S.
Published: September 2007

We report an error in “The Construct Validity of Three Entry Level Personality Inventories Used in the UK: A Cautionary Case Study” by Neil Anderson and Deniz S. Ones (European Journal of Personality, 2003, Vol. 17, S39–S66). We also alert the reader to a potential data shift of one data row in the dataset reported on in Anderson and Ones (2003) and provide an alternate table. Copyright © 2007 John Wiley & Sons, Ltd.
Resveratrol sensitizes androgen independent prostate cancer cells to death‐receptor mediated apoptosis through multiple mechanisms
Authors: Gill Catherine , Walsh Sinead E. , Morrissey Colm , Fitzpatrick John M. , Watson R. William G.
Published: September 2007

BACKGROUND

A critical factor in prostate cancer development and progression is the altered expression of apoptotic regulatory proteins which renders cells resistant to both hormone‐ and chemo‐therapies. Resveratrol, a dietary component with chemopreventive properties has been reported to resensitize a variety of cancer cell types to apoptosis. In the current study, the ability of resveratrol pre‐treatment to sensitize hormone refractory prostate cancer cell lines (PC‐3 and DU145) to apoptosis and the mechanisms involved were investigated.

METHODS

Apoptosis was assessed using several established parameters and protein expression was analyzed by Western blot and flow cytometry. IAP knockdown was achieved using RNAi while inhibition of Akt phosphorylation was achieved by pre‐incubation with the PI3‐kinase inhibitor LY294002.

RESULTS

Pre‐treatment with resveratrol sensitized PC‐3 and DU145 cells to agents that specifically target death receptors (TRAIL, Fas, TNFα) but not agents that initiate apoptosis through other mechanisms (Etoposide, Paclitaxel, Tunicamycin, Thapsigargin). Resveratrol pre‐treatment altered the expression of IAPs and Bax, and decreased Akt phosphorylation in PC‐3 cells, leading to increased caspase activation and apoptosis. While knockdown of IAPs using siRNA did not mimic the effects of resveratrol, inhibition of Akt phosphorylation using LY294002 sensitized PC‐3 cells to TRAIL induced apoptosis but not to etoposide or tunicamycin.

CONCLUSION

Altering apoptotic susceptibility in advanced androgen independent disease requires manipulation of a broad signaling pathway. Use of resveratrol or inhibition of Akt phosphorylation may represent an important therapeutic approach in combination with conventional therapies for the treatment of prostate cancer. Prostate 67: 1641–1653, 2007. © 2007 Wiley‐Liss, Inc.
Structure of aspartate racemase complexed with a dual substrate analogue, citric acid, and implications for the reaction mechanism
Authors: Ohtaki Akashi , Nakano Yohsuke , Iizuka Ryo , Arakawa Takatoshi , Yamada Kazuhiro , Odaka Masafumi , Yohda Masafumi
Published: September 2007

Pyrococcus horikoshii OT3 aspartate racemase (PhAspR) catalyzes the interconversion between L‐ and D‐aspartate. The X‐ray structure of PhAspR revealed a pseudo mirror‐symmetric distribution of the residues around its active site, which is very reasonable for its chiral substrates, L‐aspartate and D‐aspartate. In this study, we have determined the crystal structure of an inactive mutant PhAspR complexed with a citric acid (Cit) at a resolution of 2.0 Å. Cit contains the substrate analogue moieties of both L‐ and D‐aspartate and exhibits a low competitive inhibition activity against PhAspR. In the structure, Cit binds to the catalytic site of PhAspR, which induced the conformational change to close the active site. The distance between the thiolates was estimated to be 7.4 Å, representing a catalytic state and the substrate binding modes of PhAspR. Two conserved basic residues, Arg48 and Lys164, seem to be indispensable for PhAspR activity. Arg48 is thought to be responsible for recognizing carboxyl groups of the substrates L‐/D‐aspartates and stabilizing a reaction intermediate, and Lys164 is responsible for stabilizing a closed state structure. In this structure, the L‐aspartate moiety of Cit is likely to take the substrate position of the PhAspR–substrate complex, which is very similar to that of Glutamate racemase. There is also another possibility that the two substrate analogue moieties of the bound Cit reflect the binding modes of both L‐ and D‐aspartates. Based on the PhAspR–Cit complex structure, the reaction mechanism of aspartate racemase was elucidated. Proteins 2008. © 2007 Wiley‐Liss, Inc.
Structural and enzymatic characterization of DR1281: A calcineurin‐like phosphoesterase from Deinococcus radiodurans
Authors: Shin Dong Hae , Proudfoot Michael , Lim Hyo Jin , Choi In‐Kyu , Yokota Hisao , Yakunin Alexander F. , Kim Rosalind , Kim Sung‐Hou
Published: September 2007

We have determined the crystal structure of DR1281 from Deinococcus radiodurans. DR1281 is a protein of unknown function with over 170 homologs found in prokaryotes and eukaryotes. To elucidate the molecular function of DR1281, its crystal structure at 2.3 Å resolution was determined and a series of biochemical screens for catalytic activity was performed. The crystal structure shows that DR1281 has two domains, a small α domain and a putative catalytic domain formed by a four‐layered structure of two β‐sheets flanked by five α‐helices on both sides. The small α domain interacts with other molecules in the asymmetric unit and contributes to the formation of oligomers. The structural comparison of the putative catalytic domain with known structures suggested its biochemical function to be a phosphatase, phosphodiesterase, nuclease, or nucleotidase. Structural analyses with its homologues also indicated that there is a dinuclear center at the interface of two domains formed by Asp8, Glu37, Asn38, Asn65, His148, His173, and His175. An absolute requirement of metal ions for activity has been proved by enzymatic assay with various divalent metal ions. A panel of general enzymatic assays of DR1281 revealed metal‐dependent catalytic activity toward model substrates for phosphatases (p‐nitrophenyl phosphate) and phosphodiesterases (bis‐p‐nitrophenyl phosphate). Subsequent secondary enzymatic screens with natural substrates demonstrated significant phosphatase activity toward phosphoenolpyruvate and phosphodiesterase activity toward 2′,3′‐cAMP. Thus, our structural and enzymatic studies have identified the biochemical function of DR1281 as a novel phosphatase/phosphodiesterase and disclosed key conserved residues involved in metal binding and catalytic activity. Proteins 2008. © 2007 Wiley‐Liss, Inc.
Conformational flexibility in mammalian 15S‐lipoxygenase: Reinterpretation of the crystallographic data
Authors: Choi Jongkeun , Chon Jae Kyung , Kim Sangsoo , Shin Whanchul
Published: September 2007

Lipoxygenases (LOXs) are a family of nonheme iron dioxygenases that catalyze the regioselective and stereospecific hydroperoxidation of polyunsaturated fatty acids, and are involved in a variety of inflammatory diseases and cancers. The crystal structure of rabbit 15S‐LOX1 that was reported by Gillmor et al. in 1997 has played key roles for understanding the properties of mammalian LOXs. In this structure, three segments, including 12 residues in the superficial α2 helix, are absent and have usually been described as “disordered.” By reinterpreting the original crystallographic data we were able to elucidate two different conformations of the molecule, both having well ordered α2 helices. Surprisingly, one molecule contained an inhibitor and the other did not, thereby adopting a closed and an open form, respectively. They differed in the conformation of the segments that were absent in the original structure, which is highlighted by a 12 Å movement of α2. Consequently, they showed a difference in the size and shape of the substrate‐binding cavity. The new model should provide new insight into the catalytic mechanism involving induced conformational change of the binding pocket. It may also be helpful for the structure‐based design of LOX inhibitors. Proteins 2008. © 2007 Wiley‐Liss, Inc.
Denatured state is critical in determining the properties of model proteins designed on different folds
Authors: Amatori A. , Tiana G. , Ferkinghoff‐Borg J. , Broglia R. A.
Published: September 2007

The thermodynamics of proteins designed on three common folds (SH3, chymotrypsin inhibitor 2 [CI2], and protein G) is studied with a simplified Cα model and compared with the thermodynamics of proteins designed on random‐generated folds. The model allows to design sequences to fold within a dRMSD ranging from 1.2 to 4.2 Å from the crystallographic native conformation and to study properties that are hard to be measured experimentally. It is found that the denatured state of all of them is not random but is, to different extents, partially structured. The degree of structure is more abundant for SH3 and protein G, giving rise to a weaker stability but a more efficient folding kinetics than CI2 and, even more, than the random‐generated folds. Consequently, the features of the unfolded state seem to be as important in the determination of the thermodynamic properties of these proteins as the features of the native state. Proteins 2008. © 2007 Wiley‐Liss, Inc.
Context shapes: Efficient complementary shape matching for protein–protein docking
Authors: Shentu Zujun , Al Hasan Mohammad , Bystroff Christopher , Zaki Mohammed J.
Published: September 2007

We describe an efficient method for partial complementary shape matching for use in rigid protein–protein docking. The local shape features of a protein are represented using boolean data structures called Context Shapes. The relative orientations of the receptor and ligand surfaces are searched using precalculated lookup tables. Energetic quantities are derived from shape complementarity and buried surface area computations, using efficient boolean operations. Preliminary results indicate that our context shapes approach outperforms state‐of‐the‐art geometric shape‐based rigid‐docking algorithms. Proteins 2008. © 2007 Wiley‐Liss, Inc.