bluuebunny/crossref_metadata_2025_split huggingface dataset:
Basement membrane composition in the early mouse embryo day 7
Authors: Gersdorff Nikolaus , Müller Matthias , Otto Sascha , Poschadel Ralf , Hübner Stephan , Miosge Nicolai 
Published: May 2005

AbstractBasement membranes (BM) are specialized structures of the extracellular matrix known to be involved in various early developmental processes. Despite numerous investigations on the localization of BM components, it remains unknown which molecules are expressed in early developmental stages and by which germ layers these proteins are produced. Therefore, we tested for all known laminin chains, nidogens, collagen type IV, and perlecan by means of light microscopic immunostaining and performed in situ reverse transcriptase‐polymerase chain reaction to detect the mRNAs specific for laminin α1, laminin β1, the α1 chain of collagen type IV, nidogen‐2, and perlecan in the early mouse embryo, day 7, in vivo. Only the laminin chains α1, β1, and γ1 were detected immunohistochemically throughout the entire endodermal and ectodermal BM zones of the embryo proper. The mRNA of laminin α1, laminin β1, collagen type IV, nidogen‐2 and perlecan were expressed in the ectoderm‐derived mesoderm, in the endoderm as well as in the ectoderm. In contrast, Reichert's membrane was positive for all laminin chains except for the α4, α5, β3, and γ3 chains. Moreover, maternal epithelial as well as mesenchymal cells expressed laminins, nidogen‐1 and nidogen‐2, collagen type IV, and perlecan. In conclusion, laminin‐1 might be the only laminin isoform in the early mouse embryo that, together with the other main BM components, nidogens, collagen type IV, and perlecan, is synthesized by all three germ layers. Developmental Dynamics 233:1140–1148, 2005. © 2005 Wiley‐Liss, Inc.
Developmental regulation and expression of the zebrafish connexin43 gene
Authors: Chatterjee Bishwanath , Chin Alvin J. , Valdimarsson Gunnar , Finis Carla , Sonntag Jennifer M. , Choi Bo Yon , Tao Liang , Balasubramanian Krithika , Bell Carolyn , Krufka Alison , Kozlowski David J. , Johnson Ross G. , Lo Cecilia W. 
Published: May 2005

AbstractWe cloned and sequenced the zebrafish (Danio rerio) connexin43 (Cx43α1) gene. The predicted protein sequence shows a high degree of sequence conservation. Transcript analyses revealed multiple transcription start sites and a potential alternative transcript encoding a N‐terminally truncated Cx43α1 protein. Maternal Cx43α1 transcripts were detected, with zygotic expression initiated before gastrulation. In situ hybridization revealed many Cx43α1 expression domains, including the notochord and brain, heart and vasculature, many resembling patterns seen in mammalian embryos. Of interest, a reporter construct under control of the mouse Cx43α1 promoter was observed to drive green fluorescent protein expression in zebrafish embryos in domains mimicking the native Cx43α1 expression pattern in fish and mice. Sequence comparison between the mouse and zebrafish Cx43α1 promoter sequences showed the conservation of several transcription factor motifs, which otherwise shared little overall sequence homology. The conservation of protein sequence and developmental gene regulation would suggest that Cx43α1 gap junctions are likely to have conserved roles in vertebrate embryonic development. Developmental Dynamics 233:890–906, 2005. © 2005 Wiley‐Liss, Inc.
Thg‐1pit gene expression in granule cells of the developing mouse brain and in their synaptic targets, mature Purkinje, and mitral cells
Authors: Canterini Sonia , Mangia Franco , Fiorenza Maria Teresa 
Published: May 2005

AbstractWe have studied the expression of Thg‐1pit in developing and adult mouse brain by in situ hybridization analysis. We show that, at day 12.5 of embryo development, Thg‐1pit expression is restricted to the rhombic lip, subventricular neuroepithelium/mantle zone, and lateral ganglionic eminence, namely the embryonic brain areas where granule cell precursors originate. Thereafter, Thg‐1pit expression landmarks both differentiative steps and the mature function of granule/interneuron cells in several brain districts, including cerebellum, basal forebrain, olfactory bulb, and hippocampus. In the adult, Thg‐1pit becomes also activated in mitral cells of olfactory bulb and in Purkinje cells of cerebellum, in concomitance with full development of the synaptic contacts that Purkinje and mitral cells establish with granule cells. We conclude that Thg‐1pit is relevant to specification, proliferation/migration, differentiation, and mature function of granule/interneuron cells in different brain districts, as well as to the function of mature, but not immature, Purkinje cells and mitral cells. Developmental Dynamics 234:689–697, 2005. © 2005 Wiley‐Liss, Inc.
Poly(ADP‐ribose)polymerase activity is reduced in circulating mononuclear cells from type 2 diabetic patients
Authors: Tempera Italo , Cipriani Rosalba , Campagna Gianluca , Mancini Patrizia , Gatti Alessandra , Guidobaldi Leo , Pantellini Federico , Mandosi Elisabetta , Sensi Maurizio , Quesada Piera , Mario Umberto Di , D'Erme Maria , Morano Susanna 
Published: May 2005

AbstractPoly(ADP‐ribose)polymerase (PARP‐1), a nuclear enzyme activated by DNA strand breaks, is involved in DNA repair, aging, inflammation, and neoplastic transformation. In diabetes, reactive oxygen and nitrogen species occurring in response to hyperglycemia cause DNA damages and PARP‐1 activation. Because circulating mononuclear cells (MNCs) are involved in inflammation mechanisms, these cells were chosen as the experimental model to evaluate PARP‐1 levels and activity in patients with type 2 diabetes. MNCs were isolated from 25 diabetic patients (18 M, 7 F, age, 63.5 ± 10.2 years, disease duration 17.7 ± 8.2 years) and 11 age and sex matched healthy controls. PARP‐1 expression and activity were analyzed by semi‐quantitative PCR, Western and activity blot, and immunofluorescence microscopy. PARP‐1‐mRNA expression was increased in MNCs from all diabetic patients versus controls (P < 0.01), whereas PARP‐1 content and activity were significantly lower in diabetic patients (P < 0.0001). To verify whether low PARP‐1 levels and activity were due to a proteolytic effect of caspase‐3 like, the latter activation was measured by a fluorimetric assay. Caspase‐3 activity in MNCs was significantly higher in diabetic patients versus control subjects (P < 0.0001). The different PARP‐1 behavior in MNCs from patients with type 2 diabetes could therefore be responsible for the abnormal inflammation and infection responses in diabetes. © 2005 Wiley‐Liss, Inc.
GABA receptors and nitric oxide ameliorate constrictive collagen remodeling in hyperhomocysteinemia
Authors: Shastry Suresh , Moning LaQuita , Tyagi Neetu , Steed Mesia , Tyagi Suresh C. 
Published: May 2005

AbstractElevated plasma levels of homocysteine (Hcy) are associated with vascular dementias and Alzheimer's disease. The role of Hcy in brain microvascular endothelial cell (MVEC) remodeling is unclear. Hcy competes with muscimol, an γ‐amino butyric acid (GABA)‐A receptor agonist. GABA is the primary inhibitory neurotransmitter in the brain. Our hypothesis is that Hcy induces constrictive microvascular remodeling by altering GABA‐A/B receptors. MVEC from wild type, matrix metalloproteinase‐9 (MMP‐9) knockout (−/−), heterozygote cystathionine β synthase (CBS−/+), and endothelial nitric oxide synthase knockout (eNOS−/−) mouse brains were isolated. The MVEC were incorporated into collagen (3.2 mg/ml) gels and the decrease in collagen gel diameter at 24 h was used as an index of constrictive MVEC remodeling. Gels in the absence or presence of Hcy were incubated with muscimol or baclofen, a GABA‐B receptor agonist. The results suggested that Hcy‐mediated MVEC collagen gel constriction was ameliorated by muscimol, baclofen, MMP‐9, and eNOS gene ablations. There was no effect of anti‐alpha 3 integrin. However, Hcy‐mediated brain MVEC collagen constriction was abrogated with anti‐beta‐1 integrin. The co‐incubation of Hcy with L‐arginine ameliorated the Hcy‐mediated collagen gel constriction. The results of this study indicated amelioration of Hcy‐induced MVEC collagen gel constriction by induction of nitric oxide through GABA‐A and ‐B receptors. © 2005 Wiley‐Liss, Inc.
Biologic and clinical variations of adenocarcinoma at the esophago–gastric junction: Relevance of a topographic‐anatomic subclassification
Authors: Siewert J. Rüdiger , Feith Marcus , Stein Hubert J. 
Published: May 2005

AbstractA topographic‐anatomic subclassification of adenocarcinomas of the esophago–gastric junction (AEG) in distal esophageal adenocarcinoma (AEG Type I), true carcinoma of the cardia (AEG Type II), and subcardial gastric cancer (AEG Type III) was introduced in 1987 and is now increasingly accepted and used worldwide. Our experience with now more than 1,300 resected AEG tumors indicates that the subtypes differ markedly in terms of surgical epidemiology, histogenesis and histomorphologic tumor characteristics. While underlying specialized intestinal metaplasia can be found in basically all patients with AEG Type I tumors, this is uncommon in Type II tumors and virtually absent in Type III tumors. Stage distribution and overall long‐term survival after surgical resection also shows marked differences between the AEG subtypes. Surgical treatment strategies based on tumor type allow a differentiated approach and result in survival rates superior to those reported with other approaches. The subclassification of AEG tumors thus provides a useful tool for the selection of the surgical procedure and allows a better comparison of treatment results. J. Surg. Oncol. 2005;90:139–146. © 2005 Wiley‐Liss, Inc.
Kinetic Parameters of Urease Immobilized on Modified Acrylonitrile Copolymer Membranes in the Presence and Absence of Cu(II) Ions
Authors: Godjevargova Tzonka , Gabrovska Katya 
Published: May 2005

AbstractSummary: Poly(acrylonitrile‐methylmethacrylate‐sodium vinylsulfonate) membranes were subjected to seven different chemical modifications and the amount of the newly formed groups was measured for each membrane. Urease was then covalently immobilized onto the modified membranes and the amount of bound protein was determined. The kinetic parameters Vmax and Km of the immobilized urease were studied under static and dynamic conditions. Results showed that the rate of the enzyme reaction was higher for the membranes modified with NH2OH · H2SO4, NH2NH2 · H2SO4, NaOH + EDA and NaOH + GA + EDA. It was confirmed that the reaction rate, measured under dynamic conditions, was higher than that one determined under static conditions. The influence of Cu(II) ions, as inhibitors, on the enzyme reaction kinetics (Vi and Ki) was also investigated. It turned out that the most sensitive membranes towards Cu(II) were those modified with NH2NH2 · H2SO4, NaOH + EDA and H2O2. The results initiated further investigations on the influence of other heavy metal ions (Cd(II), Zn(II), Ni(II) and Pb(II)) over urease bound to a NH2OH · H2SO4‐modified membrane. It was found that the inhibition effect of the heavy metal ions over immobilized urease decreases in the order: Cu(II) > Cd(II) > Zn(II) > Ni(II) > Pb(II).
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Lipopolymers from New 2‐Substituted‐2‐Oxazolines for Artificial Cell Membrane Constructs
Authors: Lüdtke Karin , Jordan Rainer , Hommes Peter , Nuyken Oskar , Naumann Christoph A. 
Published: May 2005

AbstractSummary: We present the synthesis of novel 2‐oxazoline monomers with different 2‐substituents and their consecutive conversion into lipopolymers by living cationic polymerization. The side functions of these monomers were varied to realize different steric needs and hydrogen bonding interactions of the polymer side chains. 2‐(2′‐N‐pyrrolidonyl‐ethyl)‐2‐oxazoline, 2‐(3′‐methoxymonoethyleneglycol)propyl‐2‐oxazoline, and 2‐(3′‐methoxytriethyleneglycol)propyl‐2‐oxazoline were synthesized. All of the monomers could be converted into the corresponding lipopolymers by living cationic polymerization using 2,3‐di‐O‐octadecyl‐1‐trifluormethansulfonyl‐sn‐glycerol as the initiator. The characterization of the 2,3‐di‐O‐octadecyl‐glycerol‐poly(2‐oxazoline) lipopolymers by NMR spectroscopy, IR spectroscopy, and gel permeation chromatography revealed that the targeted molar masses and compositions can be controlled by the initial initiator/monomer ([M]0/[I]0) ratio for all the synthesized lipopolymers. The polydispersities were found to be narrow (polydispersity indices from 1.06–1.3). The amphiphilic lipopolymers were spread at the air‐water interface (Langmuir‐Blodgett film balance) and the effect of the polymer side groups and chain lengths upon the Π‐area (A) isotherms of the corresponding lipopolymer monolayers were compared and analyzed. The impact of the polymer side functionalities on a 2D gel formation was examined using an interfacial rheometer operated in an oscillating stress‐strain mode. Interestingly enough, none of the newly synthesized lipopolymers showed a rheological transition. This somewhat surprising result not only verified that these 2D gels are not established by hydrogen bonding among hydrophilic polymer moieties, as earlier proposed, but also supported the concept of jammed surface micelles as the more likely origin for the gelation phenomenon.
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Glycopeptide and glycoprotein synthesis involving unprotected carbohydrate building blocks
Authors: Guo Zhongwu , Shao Ning 
Published: May 2005

AbstractThis review summarizes the chemical and chemoenzymatic synthesis of glycopeptides and glycoproteins using unprotected carbohydrates as key intermediates. The synthetic methods covered herein include the convergent synthesis of glycopeptides by chemoselective ligation of peptides and free glycans, solution‐ and solid‐phase synthesis of glycopeptides by sequential peptide elongation with unprotected glycosyl amino acids or short glycopeptides as building blocks, and the synthesis of glycopeptides by enzymatic and/or chemical elongation of the free glycans. The use of unprotected carbohydrates in these syntheses can circumvent the final‐stage carbohydrate deprotection, lead to highly convergent synthetic designs, and more significantly, take advantage of the commercially available free glycans isolated from nature, which could considerably facilitate the synthesis of complex glycopeptides and glycoproteins. © 2005 Wiley Periodicals, Inc.
Molecular control of mitochondrial function in preimplantation mouse embryos
Authors: Thundathil Jacob , Filion France , Smith Lawrence C. 
Published: May 2005

AbstractMitochondria play a key role in a number of physiological events during all stages of life, including the very first stages following fertilization. It is, therefore, important to understand the mechanisms controlling mitochondrial activity during early embryogenesis to determine their role in development outcome. The objective of this study was to investigate the molecular control of mitochondrial transcription and mitochondrial DNA (mtDNA) replication in mouse preimplantation embryos. We estimated the mtDNA copy number and characterized the expression patterns of two mitochondrial genes and several nuclear genes that encode mitochondrial transcription and replication factors throughout preimplantation development. Mitochondrial gene transcripts were present in larger quantities in morula and blastocyst stage embryos relative to other stages. A significant increase in the amount of mRNA for nuclear genes encoding mtDNA transcription factors was observed in eight‐cell stage embryos. Although a similar increase in the mRNA levels of nuclear genes encoding mtDNA replication factors was observed in morula and blastocyst stage embryos, the number of mtDNA molecules remained stable during preimplantation stages, suggesting that nuclear‐encoded mitochondrial transcription factors are involved in the regulation of mtDNA transcription during early development. Although transcripts of replication factors are abundant at the morula and blastocyst stage, mtDNA replication did not occur until the blastocyst stage, suggesting that the inhibition of mtDNA replication is controlled at the post‐transcriptional level during early embryogenesis. Mol. Reprod. Dev. © 2005 Wiley‐Liss, Inc.
Differential protein expression in anatomical zones of the prostate
Authors: Lexander Helena , Franzén Bo , Hirschberg Daniel , Becker Susanne , Hellström Magnus , Bergman Tomas , Jörnvall Hans , Auer Gert , Egevad Lars 
Published: May 2005

AbstractThe prostate has three anatomical zones: the peripheral (PZ), the transition (TZ), and the central (CZ) zone. It is proposed that the CZ may be of mesodermal origin, whereas the other two are of endodermal origin. Proteome patterns in the zones were characterized to test for differences. Cells were scraped from macroscopically normal areas of PZ, TZ, and CZ in radical prostatectomy specimens. After exclusion of samples with cancer or prostatic intraepithelial neoplasia, 18 cases remained for analysis. Cells were collected in a medium with protease inhibitors, and the protein material was prepared for two‐dimensional gel electrophoresis. The proteins in spots that differed quantitatively between regions were identified via mass spectrometric fingerprinting of tryptic fragments and selected tandem mass spectrometry sequence analysis. Ten proteins with significant zonal differential expression were identified, eight with underexpression in the CZ versus the PZ and the TZ (arginase II, ATP synthase, cytokeratin 8, lamin A/C, peroxiredoxin 4, protein disulfide isomerase A3, tropomyosin, and vimentin), and two with overexpression in the CZ (peroxiredoxin 2 and creatine kinase B). The PZ and TZ, although differing in terms of incidence of cancer and hyperplasia, have epithelium with highly similar major protein expression profiles. However, the protein profile of the CZ differs from that of the other regions, suggesting functional differences.
Excess ZnO addition in PZN–PLZT ceramics
Authors: Zeng X. , Ding A. L. , Liu T. , Deng G. C. , Zheng X. S. 
Published: May 2005

Abstract0.3PZN–0.7PLZT (5/55/45) ceramics with and without nonstoichiometric excess ZnO addition were prepared by a conventional mixing method. The phase structure, microstructure, and dielectric and piezoelectric properties were investigated. Improvements of performances were observed. Excess ZnO could limit the formation of pyrochlore phase and enhance the electrical properties and the degree of the diffuse phase transition. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Porous silicon matrix for chemical synthesis and chromatograpy
Authors: Lehmann V. 
Published: May 2005

AbstractThis paper reports the fabrication of a porous silicon matrix with two narrow pore size regimes: an ordered array of macropores and a network of mesopores within the walls of each macropore. Both types of pores are well defined in their length and show a narrow pore diameter distribution, but the difference in pore diameter between the two types may be as large as 103. By free choice of the dimensions for each size regime this material can be tailor‐made according to its specific application; for example as stationary phase in chromatograpy or as immobilisation and reaction site for chemical or biochemical synthesis. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fast pore etching
Authors: Frey S. , Kemell M. , Carstensen J. , Langa S. , Föll H. 
Published: May 2005

AbstractThe growth of silicon macropores under high current densities and high HF concentrations is studied. A new growth mode for porous Si has been found where pores resemble the so‐called current line oriented pores previously discovered in InP. For the achievement of that the electrolyte had to be optimized in respect to the oxidation power of the electrolyte and its conductivity. All optimizations can be explained in the framework of the “Current‐Burst‐Model (CBM)”. The resulting pores show a strong self‐organization tendency as well as the tendency towards strong (also externally visible) oscillations. The growth speed could be driven up to almost 500 µm/h while still yielding pores whose roughness can easily compete with regular grown macropores. The pore diameters achieved span 50 to 3000 nm. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Thick macroporous membranes made of p‐type silicon
Authors: Zheng J. , Christophersen M. , Bergstrom P. L. 
Published: May 2005

AbstractIn the last decade, very thick macro porous silicon (PS) has been enjoying a growing popularity in a wide range of applications. There is also an increasing demand for thick macroporous membranes with through pores. In this work, we studied the optimal etch conditions with respect to stable pore growth and high etch rate for macro PS in p‐type silicon. A single‐step etching process has been developed to tackle the problem of uniform membrane formation. Very thick (>500 µm) through‐wafer macroporous membranes on p‐type silicon with variable pore sizes and growth rates up to 0.95 µm/min have been successfully demonstrated. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Defects in U3+:CaF2 single crystals grown under different conditions by the temperature gradient technique
Authors: Su Liangbi , Xu Jun , Yang Weiqiao , Jiang Xiongwei , Dong Yongjun , Zhao Guangjun , Zhou Guoqing 
Published: May 2005

AbstractDefects in as‐grown U3+:CaF2 crystals grown with or without PbF2 as an oxygen scavenger were studied using Raman spectra, thermoluminescence glow curves, and additional absorption (AA) spectra induced by heating and γ‐irradiation. The effects of heating and irradiation on as‐grown U3+:CaF2 crystals are similar, accompanied by the elimination of H‐type centers and production of F‐type centers. U3+ is demonstrated to act as an electron donor in the CaF2 lattice, which is oxidized to the tetravalent form by thermal activation or γ‐irradiation. In the absence of PbF2 as an oxygen scavenger, the as‐grown U3+:CaF2 crystals contain many more lattice defects in terms of both quantity and type, due to the presence of O2– impurities. Some of these defects can recombine with each other in the process of heating and γ‐irradiation. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Phase correlations in the CuAlSe2–CuAlTe2 system
Authors: Korzun B. V. , Fadzeyeva A. A. , Bente K. , Schmitz W. , Kommichau G. 
Published: May 2005

AbstractAlloys in the CuAlSe2–CuAlTe2 system were synthesized in BN‐crucibles in silica tubes under vacuum to obtain the corresponding phase equilibria. X‐ray powder diffraction and thermal analytic data of the T–x phase diagram revealed a complete solid solutions series in the subsolidus region. Within the CuAlSe2xTe2(1–x) system the refined lattice parameters a and c approximately obey the Vegard rule and also the cell volume and the heat of fusion confirm linear correlations with the composition of the mixed crystals. The anion position parameter calculated after S. C. Abrahams & J. L. Bernstein (uAB) and J. E Jaffe & A. Zunger (uJZ) is greater than 0.25 and reveals a linear dependence on composition. The liquidus part of the CuAlSe2xTe2(1–x) system with x < 0.35 exhibits vertical section behaviour with a ternary peritectic followed up by a ternary monotectic whereas the region with x > 0.35 shows quasibinary equilibria. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)