bluuebunny/crossref_metadata_2025 huggingface dataset:
High preoperative prevalence of deep venous thrombosis in patients with colorectal cancer
Authors: Stender M T , Nielsen T S H , Frøkjær J B , Larsen T B , Lundbye-Christensen S , Thorlacius-Ussing O
Published: April 2007

Background

Deep venous thrombosis (DVT) is a major complication of cancer and a predictor of reduced survival. The postoperative prevalence of DVT in colorectal cancer surgery is high, but the preoperative prevalence is unknown. The aim of this observational study was to estimate the preoperative prevalence of DVT in patients with colorectal cancer.

Methods

Some 193 consecutive patients with newly diagnosed colorectal cancer admitted for intended curative surgery were examined with compression ultrasonography for DVT before surgery.

Results

DVT was detected in 15 (7·8 per cent) of the 193 patients, with a prevalence of 16 per cent in women (12 of 76) versus 2·6 per cent in men (three of 117 (adjusted odds ratio (OR) 5·8 (95 per cent confidence interval (c.i.) 1·4 to 23·2)). The risk of DVT was strongly correlated with increasing American Society of Anesthesiologists (ASA) risk score: adjusted OR 6·8 (95 per cent c.i. 1·6 to 28·7 for ASA group III or IV versus ASA group I or II). Pulmonary embolism was detected in two patients (1·0 per cent).

Conclusion

A high preoperative prevalence of DVT was observed in patients with colorectal cancer, especially among women and patients in ASA groups III and IV.
PKD1 inhibits cancer cells migration and invasion via Wnt signaling pathway in vitro
Authors: Zhang Ke , Ye Chun , Zhou Qin , Zheng Rong , Lv Xiaoyan , Chen Ye , Hu Zhongguo , Guo Hong , Zhang Zheng , Wang Yidong , Tan Ruizhi , Liu Yuhang
Published: April 2007

The ∼14 kb mRNA of the polycystic kidney disease gene PKD1 encodes a large (∼460 kDa) protein, termed polycystin‐1 (PC‐1), that is responsible for autosomal dominant polycystic kidney disease (ADPKD). The unique organization of its multiple adhesive domains (16 Ig‐like domains/PKD domains) suggests that it may play an important role in cell–cell/cell–matrix interactions. Here we demonstrated that PKD1 promoted cell–cell and cell–matrix interactions in cancer cells, indicating that PC‐1 is involved in the cell adhesion process. Furthermore in this study, we showed that PKD1 inhibited cancer cells migration and invasion. And we also showed that PC‐1 regulated these processes in a process that may be at least partially through the Wnt pathway. Collectively, our data suggest that PKD1 may act as a novel member of the tumor suppressor family of genes Copyright © 2007 John Wiley & Sons, Ltd.
Sodium Cation Migration Above the Diimine π‐System of Solvent Coordinated dpp‐BIAN Sodium Aluminum Complexes (dpp‐BIAN=1,2‐Bis[(2,6‐diisopropylphenyl)imino]acenaphthene)
Authors: Schumann Herbert , Hummert Markus , Lukoyanov Anton N. , Fedushkin Igor L.
Published: April 2007

The reactions of the disodium salt of the 1,2‐bis[(2,6‐diisopropylphenyl)imino]acenaphthene (dpp‐BIAN) ligand with one equivalent of Me2AlCl in diethyl ether, toluene, and benzene produced the complexes [Na(Et2O)2(dpp‐BIAN)AlMe2] (1), [Na(η6‐C7H8)(dpp‐BIAN)AlMe2] (2) and [Na(η6‐C6H6)(dpp‐BIAN)AlMe2] (3), respectively. Recrystallization of 1 from hexane afforded solvent‐free [{Na(dpp‐BIAN)AlMe2}n] (4) or [Na(Et2O)(dpp‐BIAN)AlMe2] (5) depending on the temperature of the solvent. The molecular structures of 1–5 have been determined by single‐crystal X‐ray diffraction. The sodium cation coordinates either one of the naphthalene rings (1) or the diimine part of the dpp‐BIAN ligand (2–5). In the complexes 2 and 3, the sodium cation additionally coordinates the toluene (2) or benzene molecule (3) in an η6‐fashion.
Biallelic germline mutations of mismatch‐repair genes
Authors: Poley Jan‐Werner , Wagner Anja , Hoogmans Monique M. C. P. , Menko Fred H. , Tops Carli , Kros Johan M. , Reddingius Roel E. , Meijers‐Heijboer Hanne , Kuipers Ernst J. , Dinjens Winand N. M. ,   on behalf of the Rotterdam Initiative on Gastrointestinal Hereditary Tumors
Published: April 2007

BACKGROUND.

Heterozygous defects in mismatch‐repair (MMR) genes cause hereditary nonpolyposis colorectal cancer (HNPCC). In this syndrome, tumors typically arise from age 25 years onward. Case reports have shown that homozygosity or compound heterozygosity for MMR gene mutations can cause multiple tumors in childhood, sometimes combined with neurofibromatosis type I (NF1)‐like features. Therefore, the authors studied the role of homozygosity or compound heterozygosity (CZ) for MMR gene defects in children with multiple primary tumors.

METHODS.

A database that contained all pediatric oncology patients who were seen between 1982 and 2003 at the author's institution was queried to identify patients aged <16 years with more than 1 tumor for whom tissue of at least 1 tumor was available. On isolated DNA, microsatellite instability (MSI) and immunohistochemistry of MMR proteins were assessed.

RESULTS.

In total, 15 patients with more than 1 tumor were identified. Abnormal test results were obtained in 2 of them, including 1 patient who was diagnosed at age 4 years with a glioblastoma (MSI‐stable; no human mutL homolog 1 [MLH1] or postmeiotic segregation increased, Saccharomyces cerevisiae 2 [PMS2] expression) and a Wilms tumor (high MSI; no MLH1 or PMS2 expression). Apart from >6 cafe‐au‐lait spots, he had no other signs of NF1. The patient had CZ identified for a pathogenic MLH1 mutation (593delAG frameshift) and an unclassified MLH1 variant (Met35Asn). There was strong evidence that this unclassified variant was a pathogenic mutation. The second patient was diagnosed with a non‐Hodgkin lymphoma (no tissue available) and an anaplastic oligodendroglioma (low MSI; no MSH6 expression) at age 4 years and 6 years, respectively. His brother had died of a medulloblastoma at age 6 years (low MSI, no MSH6 expression). Both boys had cafe‐au‐lait spots. Further genetic testing was not possible.

CONCLUSIONS.

Carriage of biallelic MMR gene defects can be associated with multiple malignancies in childhood that may differ from the standard spectrum of HNPCC tumor types. In 15 pediatric patients with multiple malignancies, the authors identified 1 clear case and 1 possible case of biallelic MMR gene defect. Recognition of the inherited nature of the tumors in these patients is important for counseling these patients and their families. Cancer 2007. © 2007 American Cancer Society.
A necessary and sufficient condition for the nirenberg problem
Authors: Chen Wenxiong , Li Congming
Published: April 2007

We seek metrics conformal to the standard ones on Sn having prescribed Gaussian curvature in case n = 2 (the Nirenberg Problem), or prescribed scalar curvature for n ≧ 3 (the Kazdan‐Warner problem). There are well‐known Kazdan‐Warner and Bourguignon‐Ezin necessary conditions for a function R(x) to be the scalar curvature of some conformally related metric. Are those necessary conditions also sufficient? This problem has been open for many years.

In a previous paper, we answered the question negatively by providing a family of counter examples.

In this paper, we obtain much stronger results. We show that, in all dimensions, if R(x) is rotationally symmetric and monotone in the region where it is positive, then the problem has no solution at all. It follows that, on S2, for a non‐degenerate, rotationally symmetric function R(θ), a necessary and sufficient condition for the problem to have a solution is that Rθ changes signs in the region where it is positive. This condition, however, is still not sufficient to guarantee the existence of a rotationally symmetric solution, as will be shown in this paper. We also consider similar necessary conditions for non‐symmetric functions. ©1995 John Wiley & Sons, Inc.
An existence and uniqueness result of a nonlinear two‐dimensional elliptic boundary value problem
Authors: Gamba Irene M.
Published: April 2007

We consider a boundary value problem for the generalized two‐dimensional flow equation Δφ = Δφ · h for h a Cα vector field, where the speed is prescribed on a part of the boundary. By using Bers theory combined with elliptic operator theory in nonsmooth domains, we show existence and uniqueness of a C2,α solution with nonvanishing gradient, and we find positive lower and upper bounds for |Δφ| along with C2,α estimates of φ, in terms of the Cα and L∞ norms of h. ©1995 John Wiley & Sons, Inc.
Entropy flux‐splittings for hyperbolic conservation laws part I: General framework
Authors: Chen Gui‐Qiang , Lefloch Philippe G.
Published: April 2007

A general framework is proposed for the derivation and analysis of flux‐splittings and the corresponding flux‐splitting schemes for systems of conservation laws endowed with a strictly convex entropy. The approach leads to several new properties of the existing flux‐splittings and to a method for the construction of entropy flux‐splittings for general situations. A large family of genuine entropy flux‐splittings is derived for several significant examples: the scalar conservation laws, the p‐system, and the Euler system of isentropic gas dynamics. In particular, for the isentropic Euler system, we obtain a family of splittings that satisfy the entropy inequality associated with the mechanical energy. For this system, it is proved that there exists a unique genuine entropy flux‐splitting that satisfies all of the entropy inequalities, which is also the unique diagonalizable splitting. This splitting can be also derived by the so‐called kinetic formulation. Simple and useful difference schemes are derived from the flux‐splittings for hyperbolic systems. Such entropy flux‐splitting schemes are shown to satisfy a discrete cell entropy inequality. For the diagonalizable splitting schemes, an a priori L∞ estimate is provided by applying the principle of bounded invariant regions. The convergence of entropy flux‐splitting schemes is proved for the 2 × 2 systems of conservation laws and the isentropic Euler system. ©1995 John Wiley & Sons, Inc.
Program derivation with verified transformations — a case study
Authors: Keller J. P. , Paige R.
Published: April 2007

A program development methodology based on verified program transformations is described and illustrated through derivations of a high level bisimulation algorithm and an improved minimum‐state DFA algorithm. Certain doubts that were raised about the correctness of an initial paper‐and‐pencil derivation of the DFA minimization algorithm were laid to rest by machine‐checked formal proofs of the most difficult derivational steps. Although the protracted labor involved in designing and checking these proofs was almost overwhelming, the expense was somewhat offset by a successful reuse of major portions of these proofs. In particular, the DFA minimization algorithm is obtained by specializing and then extending the last step in the derivation of the high level bisimulation algorithm.

Our experience suggests that a major focus of future research should be aimed towards improving the technology of machine checkable proofs — their construction, presentation, and reuse. This paper demonstrates the importance of such a technology to the verification of programs and program transformations. We believe that the utility of transformational systems to program development will ultimately rest on a practical program correctness technology. © 1996 John Wiley & Sons, Inc.
Synthesis of reversible logic for nanoelectronic circuits
Authors: De Vos Alexis , Van Rentergem Yvan
Published: April 2007

Reversible logic circuits can be synthesized hierarchically by dividing them into smaller, more manageable blocks. As all reversible circuits of a certain width w form a group, this problem relates to the partitioning of a group into (double) cosets. In this article, we propose three different strategies for the synthesis of reversible circuits, all based on group theory. We will compare these different methods and will determine which is the most efficient. Copyright © 2007 John Wiley & Sons, Ltd.
Type I collagen is a genetic modifier of matrix metalloproteinase 2 in murine skeletal development
Authors: Egeblad Mikala , Shen H.‐C. Jennifer , Behonick Danielle J. , Wilmes Lisa , Eichten Alexandra , Korets Lidiya V. , Kheradmand Farrah , Werb Zena , Coussens Lisa M.
Published: April 2007

Recessive inactivating mutations in human matrix metalloproteinase 2 (MMP2, gelatinase A) are associated with syndromes that include abnormal facial appearance, short stature, and severe bone loss. Mmp2−/− mice have only mild aspects of these abnormalities, suggesting that MMP2 function is redundant during skeletal development in the mouse. Here, we report that Mmp2−/− mice with additional mutations that render type I collagen resistant to collagenase‐mediated cleavage to TCA and TCB fragments (Col1a1r/r mice) have severe developmental defects resembling those observed in MMP2‐null humans. Composite Mmp2−/−;Col1a1r/r mice were born in expected Mendelian ratios but were half the size of wild‐type, Mmp2−/−, and Col1a1r/r mice and failed to thrive. Furthermore, composite Mmp2−/−;Col1a1r/r animals had very abnormal craniofacial features with shorter snouts, bulging skulls, incompletely developed calvarial bones and unclosed cranial sutures. In addition, trabecular bone mass was reduced concomitant with increased numbers of bone‐resorbing osteoclasts and osteopenia. In vitro, MMP2 had a unique ability among the collagenolytic MMPs to degrade mutant collagen, offering a possible explanation for the genetic interaction between Mmp2 and Col1a1r. Thus, because mutations in the type I collagen gene alter the phenotype of mice with null mutations in Mmp2, we conclude that type I collagen is an important modifier gene for Mmp2. Developmental Dynamics 236:1683–1693, 2007. © 2007 Wiley‐Liss, Inc.
Cre‐conditional expression of constitutively active Notch1 in transgenic mice
Authors: Liu Ju , Lobe Corrinne G.
Published: April 2007

The Notch signaling pathway plays a critical role during mammalian development. To bypass embryonic lethality associated with constitutive Notch1 signaling, we created transgenic mice with a floxed β‐geo/stop signal between a cytomegalo virus promoter and the constitutively active intracellular domain of Notch1 (IC‐Notch1). IC‐Notch1 is activated upon introduction of Cre recombinase and it is coexpressed with an enhanced green fluorescent protein or human placental alkaline phosphatase reporter. We created three IC‐Notch1 transgenic mouse lines and crossed them to a general Cre deletor mouse line, pCX‐Cre. The double transgenic IC‐Notch1/pCX‐Cre embryos have widespread expression of IC‐Notch1 and reporters and die before 10.5 days of gestation. Morphological and histological analysis of the double transgenic embryos indicated growth arrest and various developmental defects, including lack of neural tube closure, disorganized somites, and disrupted vasculature. The conditional IC‐Notch1 expressing transgenic mice provide a unique tool to investigate the Notch pathway using tissue‐specific Cre mice and inducible Cre systems. genesis 45:259–265, 2007. © 2007 Wiley‐Liss, Inc.
Synthesis and Reactions of Polynuclear Polyhydrido Rare Earth Metal Complexes Containing “(C5Me4SiMe3)LnH2” Units: A New Frontier in Rare Earth Metal Hydride Chemistry
Authors: Hou Zhaomin , Nishiura Masayoshi , Shima Takanori
Published: April 2007

A series of tetranuclear octahydrido rare earth metal complexes of general formula [(C5Me4SiMe3)Ln(μ‐H)2]4(THF)n (Ln = Sc, Y, Gd, Dy, Ho, Er, Tm, Lu; n = 0, 1, or 2) that contain C5Me4SiMe3 as an ancillary ligand have been prepared and structurally characterized. These hydride clusters are soluble in common organic solvents such as THF, toluene, and hexane, and maintain their tetranuclear framework in solution. Such polynuclear polyhydrido complexes exhibit extremely high and unique reactivity toward a variety of unsaturated substrates including CO, CO2, and nitriles. The reaction of these neutral polyhydrides with one equivalent of [Ph3C][B(C6F5)4] affords the corresponding cationic hydride clusters [(C5Me4SiMe3)4Ln4H7(THF)n][B(C6F5)4], which can act as catalysts for the syndiospecific polymerization of styrene and regio‐ and stereospecific cis‐1,4‐polymerization of 1,3‐cyclohexadiene. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Synthesis and Functionalization of Germanium Triphenylcorrolate: The First Example of a Partially Brominated Corrole
Authors: Nardis Sara , Mandoj Federica , Paolesse Roberto , Fronczek Frank R. , Smith Kevin M. , Prodi Luca , Montalti Marco , Battistini Gionata
Published: April 2007

Ge complexes of 5,10,15‐triphenylcorrole were prepared in refluxing dry DMF using GeCl4 as the source of Ge. Chromatographic separation of the crude reaction mixture afforded the μ‐oxo dimer 1 and the methoxy derivative 2a. The corresponding chloride 2b can be obtained by treatment of 1 or 2a with HCl. The reaction of 2a with Br2 in CHCl3/py afforded the hexabromo derivative 3 as the main product, giving the first indication of the regioselective substitution of pyrroles B and C on the corrole ring. The fully brominated open‐chain tetrapyrrole 4 was also characterized as a reaction by‐product. Different partially brominated Ge complexes 5 and 6 have been obtained by variation of reaction conditions, while the heptabromo derivative was obtained in a mixture with the corresponding fully brominated Gecorrole. Photophysical characterization of Ge corrolates confirmed the high fluorescence quantum yield of such complexes, and also led to the first observation of phosphorescence emissions from corrole complexes. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Chemistry of floral scents in four Licuala species (Arecaceae)
Authors: Meekijjaroenroj Aroonrat , Bessière Jean‐Marie , Anstett Marie‐Charlotte
Published: April 2007

Floral fragrances are known to attract pollinators. Resemblances in the chemistry of floral scents may associate a group of plants to the same array of pollinators and/or mirror the systematics of related species. In this study, floral volatiles were extracted and all compounds identified from four Licuala palms: L. grandis, L. mattanensis, L. spinosa and L. lauterbachii. A typical emission of isoprenoid compounds in the four species was revealed. However, each species was characterized by a different chemical composition of the floral bouquet. The relative importance of similarity and diversity found in floral scent chemistry for pollination and systematics is discussed. Copyright © 2007 John Wiley & Sons, Ltd.
BILU implicit multiblock Euler/Navier–Stokes simulation for rotor tip vortex and wake convection
Authors: Zhong Bowen , Shaw Scott , Qin Ning
Published: April 2007

In this paper, a block incomplete lower–upper (BILU) decomposition method is incorporated with a multiblock three‐dimensional Euler/Navier–Stokes solver for simulation of hovering rotor tip vortices and rotor wake convection. Results of both Euler and Navier–Stokes simulations are obtained and compared with experimental observations. The comparisons include surface pressure distributions and tip vortex trajectories. The comparisons suggest that resolution of the boundary layer is important for the accurate evaluation of the blade surface loading, but is less so for the correct prediction of the vortex trajectory. Numerical tests show that, using Courant–Friedrichs–Lewy (CFL) number of 10 or 30 with the developed BILU implicit scheme can be 6–7 times faster than an explicit scheme. The importance of solution acceleration schemes that increase the permitted time‐step is illustrated by comparing the evolving wake structures at different stages of the calculation. In contrast to fixed wing simulations, the extent of the wake structures is shown to require resolution of large physical time. This observation explains the poor performance that is obtained when employing convergence acceleration strategies originally intended for solution of equilibrium problems, such as the multigrid methods. Copyright © 2007 John Wiley & Sons, Ltd.
Effect of the Anodic Diffusion Layer on the Performance of Liquid Fuel Cells
Authors: Xie F. , Chen C. , Meng H. , Shen P. K.
Published: April 2007

Novel diffusion layers for liquid direct methanol fuel cells (DMFCs) are designed and fabricated. The factors affecting the performance of DMFCs are determined. The results demonstrate that the diffusion layers made by micrometer scale particles and a hydrophilic binder can reduce the liquid sealing effect and increase the mass transfer property. The performance of DMFCs made using novel diffusion layers is greatly improved. The porous structure of such diffusion layers may improve the channels therein, which allows liquid methanol to diffuse in and gaseous CO2 to diffuse out easily. Higher methanol concentrations can be used due to the formation of a larger three‐phase interfacial area.
Neuroimaging endophenotypes: Strategies for finding genes influencing brain structure and function
Authors: Glahn David C. , Thompson Paul M. , Blangero John
Published: April 2007

It is vitally important to identify the genetic determinants of complex brain‐related disorders such as autism, dementia, mood disorders, and schizophrenia. However, the search for genes predisposing individuals to these illnesses has been hampered by their genetic and phenotypic complexity and by reliance upon phenomenologically based qualitative diagnostic systems. Neuroimaging endophenotypes are quantitative indicators of brain structure or function that index genetic liability for an illness. These indices will significantly improve gene discovery and help us to understand the functional consequences of specific genes at the level of systems neuroscience. Here, we review the feasibility of using neuroanatomic and neuropsychological measures as endophenotypes for brain‐related disorders. Specifically, we examine specific indices of brain structure or function that are genetically influenced and associated with neurological and psychiatric illness. In addition, we review genetic approaches that capitalize on the use of quantitative traits, including those derived from brain images. Hum Brain Mapp, 2007. © 2007 Wiley‐Liss, Inc.
An empirical analysis of nonstationarity in a panel of interest rates with factors
Authors: Moon Hyungsik Roger , Perron Benoit
Published: April 2007

This paper studies nonstationarities in a panel of Canadian and US interest rates of different maturities and risk. We focus on methods which model the cross‐sectional dependence within the panel as a linear dynamic factor model, and decompose our data into common and idiosyncratic components that we analyze in turn. Our results suggest the presence of a single nonstationary factor in our panel. Since some of the idiosyncratic components are stationary, we conclude that these series are cointegrated. Finally, the dominant factors can be interpreted as level and slope factors as in the term structure literature. Copyright © 2007 John Wiley & Sons, Ltd.
Heterogeneity and cross section dependence in panel data models: theory and applications introduction
Authors: Baltagi Badi H. , Hashem Pesaran M.
Published: April 2007

The papers included in this special issue are primarily concerned with the problem of cross section dependence and heterogeneity in the analysis of panel data models and their relevance in applied econometric research. Cross section dependence can arise due to spatial or spill over effects, or could be due to unobserved (or unobservable) common factors. Much of the recent research on non‐stationary panel data have focussed on this problem. It was clear that the first generation panel unit root and cointegration tests developed in the 1990's, which assumed cross‐sectional independence, are inadequate and could lead to significant size distortions in the presence of neglected cross‐section dependence. Second generation panel unit root and cointegration tests that take account of possible cross‐section dependence in the data have been developed, see the recent surveys by Choi (2006) and Breitung and Pesaran (2007). The papers by Baltagi, Bresson and Pirotte, Choi and Chue, Kapetanios, and Pesaran in this special issue are further contributions to this literature. The papers by Fachin, and Moon and Perron are empirical studies in this area. Controlling for heterogeneity has also been an important concern for empirical researchers with panel data methods promising better handle on heterogeneity than cross‐section data methods. The papers by Hsiao, Shen, Wang and Weeks, Pedroni and Serlenga and Shin are empirical contributions to this area. Copyright © 2007 John Wiley & Sons, Ltd.
The murine ortholog of the SHP‐2 binding molecule, PZR accelerates cell migration on fibronectin and is expressed in early embryo formation
Authors: Roubelakis Maria G. , Martin‐Rendon Enca , Tsaknakis Grigorios , Stavropoulos Athanassios , Watt Suzanne M.
Published: April 2007

The human P zero‐related protein (hPZR) has a unique function in regulating cell migration. This activity is dependent on both its cytoplasmic immunoreceptor tyrosine inhibitory motif (ITIM) and its interaction with the tyrosine protein phosphatase, src homology phosphatase‐2 (SHP‐2). Here, using in silico and cDNA cloning approaches, we identify the murine ITIM‐containing hPZR ortholog, mPZR, together with its ITIM‐less isoform, mPZRb. We demonstrate that, like hPZR, these type 1 integral murine transmembrane isoforms are derived by differential splicing from a single gene transcription unit on mouse chromosome 1, and differ only in the sequence of their cytoplasmic domains. Importantly, mPZR mimicks hPZR functionally by accelerating SHP‐2‐mediated cell migration on fibronectin. Interestingly, we further demonstrate that although neither mPZR nor mPZRb is expressed in murine pluripotent embryonic stem cells, they first appear at approximately day 3 of blastocyst formation in vivo and of embryoid body formation in vitro. These studies thus provide the basis for defining the function of the mPZR isoforms in vivo, particularly with respect to their roles in regulating SHP‐2‐dependent cell migration during development. J. Cell. Biochem. 102: 955–969, 2007. © 2007 Wiley‐Liss, Inc.
Identification of genetic networks involved in the cell growth arrest and differentiation of a rat astrocyte cell line RCG‐12
Authors: Takasaki Ichiro , Takarada Satoko , Fukuchi Mamoru , Yasuda Makoto , Tsuda Masaaki , Tabuchi Yoshiaki
Published: April 2007

The purpose of the present study is to establish and characterize a conditionally immortalized astrocyte cell line and to clarify the genetic networks responsible for the cell growth arrest and differentiation. A conditionally immortalized astrocyte cell line, RCG‐12, was established by infecting primary cultured rat cortical glia cells with a temperature‐sensitive simian virus 40 large T‐antigen. At a permissive temperature of 33°C, the large T‐antigen was expressed and cells grew continuously. On the other hand, the down‐regulation of T‐antigen at a non‐permissive temperature of 39°C led to growth arrest and differentiation. The cells expressed astrocyte‐expressed genes such as glial fibrillary acidic protein. Interestingly, the differentiated condition induced by the non‐permissive temperature significantly elevated the expression levels of several astrocyte‐expressed genes. To identify the detailed mechanisms by which non‐permissive temperature‐induced cell growth arrest and differentiation, we performed high‐density oligonucleotide microarray analysis and found that 556 out of 15,923 probe sets were differentially expressed 2.0‐fold. A computational gene network analysis revealed that a genetic network containing up‐regulated genes such as RB, NOTCH1, and CDKN1A was associated with the cellular growth and proliferation, and that a genetic network containing down‐regulated genes such as MYC, CCNB1, and IGF1 was associated with the cell cycle. The established cell line RCG‐12 retains some characteristics of astrocytes and should provide an excellent model for studies of astrocyte biology. The present results will also provide a basis for understanding the detailed molecular mechanisms of the growth arrest and differentiation of astrocytes. J. Cell. Biochem. 102: 1472–1485, 2007. © 2007 Wiley‐Liss, Inc.
Esterases and putative lipases from tropical isolates of Aureobasidium pullulans
Authors: Kudanga Tukayi , Mwenje Eddie , Mandivenga Faith , Read John S.
Published: April 2007

Esterases and lipases have been studied in a number of fungi, though very little is known about esterases from Aureobasidium pullulans especially from the African tropics. In this study, forty‐two Zimbabwean isolates were screened for lipase activity on tributyrin agar. Extracellular esterase activities of seven selected isolates were studied under varying conditions using para ‐nitrophenol acetate as substrate. Twenty isolates (48%) showed lipolytic activity; sixteen showed negative results for lipase activity while the rest showed weak activities. Esterase activities in broth cultures ranged from 0.011–0.223 mmol/μg protein/min while activities ranged from 1.5–12.8 U/ml under solid state fermentation. The esterases were optimally active at pH 7.6–8.0, showed a temperature optimum of 35 °C and retained more than 50% activity at temperatures up to 60 °C and at pH 4.0–7.0 after 150 min. Enzyme production was optimal after 5–6 days with diammonium hydrogen phosphate as nitrogen source. Isolates showed variations in preference for carbon source for esterase production. The A. pullulans esterases differed from most fungal esterases in that they are optimally active in alkaline conditions and are active over a broad pH range. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PCR monitoring of Lactobacillus and Bifidobacterium dynamics in fermentations by piglet intestinal microbiota
Authors: Moura Patrícia , Simões Fernanda , Gírio Francisco , Loureiro‐Dias Maria C. , Esteves M. Paula
Published: April 2007

A new group‐specific primer (Lact71R), targeting the 16S‐23S rDNA intergenic spacer region of Lactobacillus, was tested in its specificity to amplify rDNA of lactobacilli from piglet intestinal origin by polymerase chain reaction (PCR). Lact71R and Lab0677F, a Lactobacillus group‐specific primer targeting the 16S rDNA, generated a common amplicon by PCR with DNA from Lactobacillus and Pediococcus reference strains, but not from Weissella strains. Sequence analysis of clones obtained by PCR amplification with Lact71R and Lab0677F and total DNA isolated from the ileal, caecal and colonic contents of one piglet resulted in Lactobacillus and Lactobacillus ‐like sequences mainly retrieved from intestinal environments. The primer pair was further validated in a culture independent PCR‐analysis to monitor broad fluctuations of lactobacilli populations in fructo‐oligosaccharides (FOS) fermentations by piglet intestinal microbiota. Bifidobacterium genus‐specific primers were also used for PCR titre determination throughout FOS fermentations, in parallel with lactate and short chain fatty acids (SCFA) quantification. Increases between PCR titres were correlated with lactate detection in early stages of fermentation. Based on the obtained results, a simple monitoring PCR approach is proposed, foreseeing its application to the study of the dynamics of specific bacterial populations in complex environments. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Expression and characterization of the chaperonin molecular machine from the hyperthermophilic archaeon Pyrococcus furiosus
Authors: Chen Hua‐You , Chu Zhong‐Mei , Ma Yan‐He , Zhang Yi , Yang Sheng‐Li
Published: April 2007

The chaperonin molecular machine from hyperthermophilic archaeon Pyrococcus furiosus was studied in this paper. The Pyrococcus furiosus chaperonin gene (PfCPN) was amplified by PCR from the Pyrococcus furiosus genomic DNA, and expressed in Escherichia coli BL21‐Codonplus(DE)3‐RIL. The recombinant PfCPN was purified to homogeneity by using ion‐exchange and size‐exclusion chromatography. It was found that the ATPase activity of the PfCPN was highest at 88 °C, and there existed a nested cooperativity of the ATPase activity of the PfCPN. This result suggested that nested allosteric behavior may be common to chaperonin molecular machines from archaea. The half‐life (t1/2) of the ATPase activity of the PfCPN at 100 °C was about 60 min. The PfCPN displayed chaperone activity in preventing lysozyme from thermal inactivation. This chaperone activity was in an ATP‐dependent manner. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Raman spectroscopy of dawsonite NaAl(CO3)(OH)2
Authors: Frost Ray L. , Bouzaid Jocelyn M.
Published: April 2007

Raman spectroscopy both at 298 and 77 K complemented with infrared spectroscopy was used to study the structure of dawsonite. Previous crystallographic studies concluded that the structure of dawsonite was a simple one; however, both Raman and infrared spectroscopy show that this conclusion is incorrect. Multiple bands are observed in both the Raman and infrared spectra in the antisymmetric stretching and bending regions, showing that the symmetry of the carbonate anion is reduced and in all probability the carbonate anions are not equivalent in the dawsonite structure. Multiple OH deformation vibrations centred around 950 cm−1 in both Raman and infrared spectra show that the OH units in the dawsonite structure are non‐equivalent. Calculations using the position of the Raman and infrared OH stretching vibrations enabled estimates of the hydrogen‐bond distances of 0.2735 and 0.27219 pm at 298 K, and 0.27315 and 0.2713 pm at 77 K to be made. This indicates strong hydrogen bonding of the OH units in the dawsonite structure. Copyright © 2007 John Wiley & Sons, Ltd.
Raman spectroscopy of optical phonons confined in semiconductor quantum dots and nanocrystals
Authors: Rolo A. G. , Vasilevskiy M. I.
Published: April 2007

This paper gives an overview of theoretical and experimental results on Raman‐active optical phonon modes confined in nearly spherical nanocrystals (NCs) of polar semiconductor materials with cubic crystal structure. A systematic consideration of the effect of reduced dimensionality on both electrons and phonons is presented. The theoretical approach is based on a continuum lattice dynamics model and the effective mass approximation for electronic states in the NCs. Calculated resonant and non‐resonant Raman scattering spectra are compared to experimental data stressing the effects of phonon confinement, type of excitation, polaron correction to the exciton spectrum enhanced because of the reduced dimensionality, and individual features of the NC material. Copyright © 2007 John Wiley & Sons, Ltd.
Effect of collagen preparations used as carriers of potassium iodide on retention of iodine and thiamine during cooking and storage of pork meatballs
Authors: Waszkowiak Katarzyna , Szymandera‐Buszka Krystyna
Published: April 2007

The application of collagen preparations as carriers of iodine salts in the production of meat dishes was investigated in this study. Meatballs with addition of collagen fibre or collagen hydrolysate, both impregnated with potassium iodide, were cooked and cold‐ or freezer‐stored. After thermal processing and during storage of meatballs the iodine and thiamine contents were determined and compared to their contents in meatballs to which potassium iodide was introduced using iodized table salt. It has been shown that the application of both collagen preparations as carriers of potassium iodide increases the stability of this compound during cooking and storage of meatballs in comparison to its stability in products with iodized table salt. Collagen preparations, improving potassium iodide stability, also limit thiamine losses in the product. A more advantageous effect, both on iodine and thiamine retention, is achieved for the collagen preparation with a higher water binding capacity. Copyright © 2007 Society of Chemical Industry
Combinatorial Methods and Informatics Provide Insight into Physical Properties and Structure Relationships during IPN Formation
Authors: Nowers Joseph R. , Broderick Scott R. , Rajan Krishna , Narasimhan Balaji
Published: April 2007

Combinatorial methods and informatics are applied to the study of complex property‐structure‐processing relationships during interpenetrating polymer network formation in an epoxy/acrylate system. Principal component analysis of a dataset that covers different compositions and process sequences successfully identifies the most unique samples as well as relationships between material properties. The relationships between material properties can be exploited in future investigations by allowing high throughput screening and as a guide for engineering materials. The use of combinatorial methods, high throughput screening, and informatics will lead to accelerated material design.

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Synergistic effects of multiple treatments, and both DNA and RNA direct bindings on, green tea catechins
Authors: Kuzuhara Takashi , Tanabe Akitoshi , Sei Yoshihisa , Yamaguchi Kentaro , Suganuma Masami , Fujiki Hirota
Published: April 2007

This article reviews two main topics: (1) the synergistic effects of multiple treatments with green tea catechin and (2) the direct binding of (−)‐epigallocatechin gallate (EGCG) to both DNA and RNA molecules. Japanese drink green tea throughout the day, so we studied whether multiple treatments of cells with EGCG would enhance the expression of apoptosis‐related genes, such as growth arrest and DNA damage‐inducible gene (GADD153) and cyclin‐dependent kinase inhibitor gene (p21waf1): The results suggest that the synergistic enhancement of both GADD153 and p21waf1 gene expressions by multiple treatments plays a significant role in human cancer prevention with green tea beverage. Our previous observation—that nucleic acids extracted from catechin‐treated cells are colored—allowed us to speculate that catechins directly interact with nucleic acids. Surface plasmon resonance assay (Biacore) indicated that four catechins, EGCG, (−)‐epicatechin gallate (ECG), (+)‐gallocatechin gallate (GCG), and (+)‐catechin gallate (CG), bound to DNA oligomers. Cold spray ionization mass spectrometry (CSI‐MS) analysis showed that one to three EGCG molecules bound to single‐stranded 18 mers of DNA and RNA. Moreover, one or two molecules of EGCG bound to double‐stranded AG:CT oligomers of various nucleotide lengths. Double‐stranded DNA (dsDNA) oligomers were detected only as EGCG‐bound forms at high temperature, whereas at low temperature both the free and bound forms were detected, suggesting that EGCG protects double‐stranded DNA oligomers from double‐stranded melting into single‐stranded DNA. We assume that catechins accumulate in both double‐stranded DNA and RNA molecules through multiple administrations of green tea beverage in in vivo, and that the accumulated green tea catechins play a significant role for human cancer prevention. © 2007 Wiley‐Liss, Inc.
Birth of correctly genotyped calves after multiplex marker detection from bovine embryo microblade biopsies
Authors: Peippo Jaana , Viitala Sirja , Virta Jouni , Räty Mervi , Tammiranta Niina , Lamminen Terttu , Aro Johanna , Myllymäki Hannu , Vilkki Johanna
Published: April 2007

We report a method for multiplex genotyping of bovine embryo microblade biopsies. We have tested the reliability of the method and the viability of the embryos in vitro and in vivo. Two polymorphic gene markers (GHR F279Y and PRLR S18N) associated with milk production traits and one marker for sex diagnosis (ZFX/ZFY) were genotyped simultaneously with a method that combines nested PCR and allelic discrimination. To test the accuracy of genotyping, in the first experiment the genotypes of 134 biopsies from in vitro produced embryos were compared to genotypes determined from the corresponding embryos after biopsy. The method proved to be highly accurate as only in three cases (two for PRLR S18N and one for GHR F279Y) out of 395 genotypes the genotype was in disagreement between the two samples. The viability of similarly biopsied embryos was tested in parallel: after 24‐hr culture 94.6% of embryos recovered in vitro. In the second experiment, a total of 150 in vivo‐produced embryos were biopsied on Day 7 and genotyped. After the genotyping results were obtained on Day 8, female embryos were selected for transfer. From a total of 57 selected embryos 43 were transferred individually and 14 as pairs. After single embryo transfers, 19 recipients became pregnant and after embryo transfers in pairs one became pregnant. The success of genotyping was tested with the genotypes of donors and bulls and also from the hair samples of born calves. All calves were females and of the same genotypes determined from the biopsy. Mol. Reprod. Dev. 74: 1373–1378, 2007. © 2007 Wiley‐Liss, Inc.
Isolation and characterization of a novel Xenopus gene (xVAP019) encoding a DUF1208 domain containing protein
Authors: Ruan Xu Zhi , Yang Han Suo , Yao Shao Hua , Ma Fan Xin , Zhao Xin Yu , Yan Fei , Wang Chun Ting , Lai Song Tao , Deng Hong Xin , Wei Yu Quan
Published: April 2007

We have identified a novel Xenopus gene (xVAP019) encoding a DUF1208 domain containing protein. Using whole‐mount in situ hybridization and RT‐PCR, we found abundant xVAP019 maternal transcripts in the animal hemisphere during the cleavage stages and blastula stages. During gastrulation xVAP019 is differentially expressed with higher levels in the animal helf and the highest in marginal zone, then further expressed widely at neuronal stages with strongest signals in the prospective CNS regions and the epidermal ectoderm. Subsequently xVAP019 was expressed predominantly in the head, the eyes, the otic vesicle, branchial arches, spinal cord, notochord, somites, and tailbud. It is absent or very weak in the endoderm. Injecting a morpholino oligo complementary to xVAP019 mRNA or injecting a caped xVAP019 mRNA caused most of embryos to die during gastrulation and neurulation. Overexpression of xVAP019 mRNA also led to eye defect, shorten interocular distance, small body size and abnormal pigment formation in parts of the survival embryos. Similar effects were induced by injecting the xVAP019 human homologous gene FAM92A1. Our results suggest that xVAP019 is essential for the normal ectoderm and axis mesoderm differentiation and embryos survival. This investigation is for the first time in vivo study examining the role of this novel gene and reveals an important role of xVAP019 in embryonic development. Mol. Reprod. Dev. 74: 1505–1513, 2007. © 2007 Wiley‐Liss, Inc.
DNA methylation and histone acetylation patterns in cultured bovine fibroblasts for nuclear transfer
Authors: Giraldo Angelica M. , Lynn John W. , Purpera Megan N. , Godke Robert A. , Bondioli Kenneth R.
Published: April 2007

Evidence indicates that failure of nuclear transfer (NT) embryos to develop normally can be attributed, at least partially, to the use of a differentiated cell nucleus as the donor karyoplast. It has been hypothesized that blastocyst production and development to term of cloned embryos may differ between population doublings (PDs) of the same cell line as a consequence of changes in DNA methylation and histone acetylation patterns during in vitro culture. The objective of this study was to determine gene expression patterns of the chromatin remodeling proteins DNA methyltransferase‐1 (Dnmt1), methyl CpG binding protein‐2 (MeCP2), and histone deacetyltransferse‐1 (HDAC1), in addition, to measuring levels of DNA methylation and histone acetylation of bovine fibroblast cells at different PDs. Bovine fibroblast cell lines were established from four 50‐day fetuses. Relative levels of Dnmt1, MeCP2, HDAC1, methylated DNA, and acetylated histone were analyzed at PDs 2, 7, 15, 30, 45, and 70. RNA levels of Dnmt1, HDAC1, and MeCP2 were examined using Q‐PCR. Global levels of methylated DNA and acetylated histone were determined by incubation of fixed cells with an anti‐5‐methylcytidine and anti‐acetyl‐histone H3 antibody, respectively. Cells were labeled with a second antibody, counter‐stained with propidium iodide and analyzed by flow cytometry. These data demonstrate that chromatin remodeling protein mRNAs involved in epigenetic modifications are altered during in vitro culture. Methylated DNA and acetylated histone patterns of in vitro cells change with time in culture. Subsequent use of these cells for NT will provide insight as to how these epigenetic modifications affect reprogramming. Mol. Reprod. Dev. 74: 1514–1524, 2007. © 2007 Wiley‐Liss, Inc.
Flow cytometric assessment of feto‐maternal hemorrhage; a comparison with Betke–Kleihauer
Authors: Fernandes Bernard J. , von Dadelszen Peter , Fazal Inez , Bansil Nikki , Ryan Greg
Published: April 2007

Objectives

Assessing the number of fetal cells in the maternal circulation quantifies the volume of feto‐maternal hemorrhage, enhancing the ability to provide effective prevention of Rhesus (Rh) allommunization and appropriate fetal surveillance in cases of significant feto‐maternal hemorrhage.

Methods

Having developed a standard curve with maternal samples spiked with known volumes of fetal red blood cells, we used a flow cytometric method using fluorescent labeled antihemoglobin F to quantitate fetal cells in the maternal circulatory system in two groups of women undergoing chorionic villus sampling (CVS), by either biopsy forceps or cannula aspiration (n = 170 women). We compared these results with the gold standard, the Betke–Kleihauer test.

Results

Our results show good correlation between the flow cytometric method and the traditional Betke–Kleihauer method for fetal red cell quantitation (r2 = 0.99). Fetal red blood cells were identified in 10 women by the Betke–Kleihauer method, and in 26 women by flow cytometry. CVS was not associated with an increase in feto‐maternal hemorrhage.

Conclusion

Flow cytometry was both more sensitive and more timely for the quantitation of feto‐maternal hemorrhage than was Betke–Kleihauer. Copyright © 2007 John Wiley & Sons, Ltd.
Four cases of fetal hypoechoic hepatomegaly associated with Trisomy 21 and transient abnormal myelopoiesis
Authors: Kikuchi Akira , Tamura Nozomi , Ishii Keisuke , Takakuwa Koichi , Matsunaga Masamichi , Sudo Norihito , Tanaka Kenichi
Published: April 2007

Objective

Our objective was to determine the clinical significance of fetal hypoechoic hepatomegaly and serial change of liver sizes.

Methods

The liver sizes of four fetuses with hypoechoic hepatomegaly were serially estimated by liver length, as measured from the dome of the right hemidiaphragm to the tip of the right lobe.

Results

All cases were associated with trisomy 21 or transient abnormal myelopoiesis (TAM). Two cases were trisomy 21 with TAM, one case was a phenotypically normal newborn, who had developed TAM during the fetal period, and the last case was trisomy 21 without TAM. In the last case, it is speculated that TAM had developed and regressed completely before birth. Two cases, whose hepatomegaly had improved before birth, showed good prognosis and the other two cases, in whom improvement had not been observed, resulted in death after birth by liver failure.

Conclusion

These experiences show that one of the differential diagnoses of hypoechoic hepatosplenomegaly is TAM and that the change of live size is a predictor of prognosis. Copyright © 2007 John Wiley & Sons, Ltd.
Effect of response mode and subject characteristics on learning in programed instruction
Authors: Sulzbacher Stephen
Published: April 2007

60 Ss took a program in one of three ways: writing the answer, “thinking” the answer without writing it, or reading a program with the answers filled in. Results indicated no significant differences among the groups on two measures of amount learned. Low positive correlations were obtained between amount learned and IQ and reading comprehension of the Ss. Percent error on test frames within the program was negatively correlated with adjusted gain scores (r = −0.71). Results were also related to possible pragmatic applications.