bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chromosome arm 16q in Wilms tumors: Unbalanced chromosomal translocations, loss of heterozygosity, and assessment of the CTCF gene
Authors: Yeh Albert , Wei Michelle , Golub Samuel B. , Yamashiro Darrell J. , Murty Vundavali V. , Tycko Benjamin 
Published: September 2002

AbstractChromosome arm 16q is a common site of loss of heterozygosity (LOH) in Wilms tumors (WTs). The mechanism and consequences of 16q LOH are not known, but the CTCF gene, in band 16q22, is a candidate target gene. CTCF protein binds to DNA upstream of the H19 gene on chromosome band 11p15, and maintains normal imprinting of H19 and IGF2. Thus, its loss might predispose to de novo methylation of the maternal allele of H19 and loss of imprinting (LOI) of IGF2 in WTs. We mapped Chr16 LOH in WTs and correlated this with unbalanced chromosomal translocations and histopathology. We also analyzed the CTCF gene for its mRNA and protein expression and DNA sequence, and we investigated correlations with methylation of H19mat. In our series, unbalanced t(1;16) chromosomal translocations were a major pathway for Chr16 loss of heterozygosity, and this LOH was correlated significantly with tumor anaplasia. CTCF mapped in the minimal region of Chr16 LOH. However, we found no correlation between Chr16 LOH, or loss of CTCF mRNA or protein, and methylation of H19mat. Some WTs contained reduced amounts of CTCF protein, but among these were cases with and without H19mat methylation. Rare WTs with simultaneous 16q LOH and H19mat methylation lacked CTCF mutations. These data argue against the CTCF gene as a target of Chr16 LOH in WTs, but leave open the possibility that post‐transcriptional loss of CTCF protein may account for some instances of LOI. © 2002 Wiley‐Liss, Inc.
The role of Alu repeat clusters as mediators of recurrent chromosomal aberrations in tumors
Authors: Kolomietz Elena , Meyn M. Stephen , Pandita Ajay , Squire Jeremy A. 
Published: September 2002

AbstractThere is increasing evidence for the involvement of repetitive DNA sequences as facilitators of some of the recurrent chromosomal rearrangements observed in human tumors. The high densities of repetitive DNA, such as Alu elements, at some chromosomal translocation breakpoint regions has led to the suggestion that these sequences could provide hot spots for homologous recombination, and could mediate the translocation process and elevate the likelihood of other types of chromosomal rearrangements taking place. The Alu core sequence itself has been suggested to promote DNA strand exchange and genomic rearrangement, and it has striking sequence similarity to χ (which has been shown to stimulate recBCD‐mediated recombination in Escherichia coli). Alu repeats have been shown to be involved in the generation of many constitutional gene mutations in meiotic cells, attributed to unequal homologous recombination and consequent deletions and/or duplication events. It has recently been demonstrated that similar deletion events can take place in neoplasia because several types of leukemia‐associated chromosomal rearrangements frequently have submicroscopic deletions immediately adjacent to the translocation breakpoint regions. Significantly, these types of deletions appear to be more likely to take place when the regions subject to rearrangement contain a high density of Alu repeats. With the completion of the Human Genome Project, it will soon be possible to create more comprehensive maps of the distribution and densities of repetitive sequences, such as Alu, throughout the genome. Such maps will offer unique insights into the relative distribution of cancer translocation breakpoints and the localization of clusters of repetitive DNA. © 2002 Wiley‐Liss, Inc.
Remyelination of the spinal cord following intravenous delivery of bone marrow cells
Authors: Akiyama Yukinori , Radtke Christine , Honmou Osamu , Kocsis Jeffery D. 
Published: September 2002

AbstractBone marrow contains a population of pluripotent cells that can differentiate into a variety of cell lineages, including neural cells. When injected directly into the demyelinated spinal cord they can elicit remyelination. Recent work has shown that following systemic delivery of bone marrow cells functional improvement occurs in contusive spinal cord injury and stroke models in rat. We report here that secondary to intravenous introduction of an acutely isolated bone marrow cell fraction (mononuclear fraction) from adult rat femoral bones separated on a density gradient, ultrastructurally defined remyelination occurs throughout a focal demyelinated spinal cord lesion. The anatomical pattern of remyelination was characteristic of both oligodendrocyte and Schwann cell myelination; conduction velocity improved in the remyelinated axons. When the injected bone marrow cells were transfected to express LacZ, β‐galactosidase reaction product was observed in some myelin‐forming cells in the spinal cord. Intravenous injection of other myelin‐forming cells (Schwann cells and olfactory ensheathing cells) or the residual cell fraction of the gradient did not result in remyelination, suggesting that remyelination was specific to the delivery of the mononuclear fraction. While the precise mechanism of the repair, myelination by the bone marrow cells or facilitation of an endogenous repair process, cannot be fully determined, the results demonstrate an unprecedented level of myelin repair by systemic delivery of the mononuclear cells. GLIA 39:229–236, 2002. © 2002 Wiley‐Liss, Inc.
Phenotypic analysis of mice deficient in the major myelin protein MOBP, and evidence for a novel Mobp isoform
Authors: Yool D. , Montague P. , McLaughlin M. , McCulloch M.C. , Edgar J.M. , Nave K.‐A. , Davies R.W. , Griffiths I.R. , McCallion A.S. 
Published: September 2002

AbstractMyelin‐associated oligodendrocytic basic protein (MOBP) is a recently identified major component of central nervous system (CNS) myelin. We previously reported a detailed characterization of the genomic region encompassing the Mobp gene, elucidating the complex series of transcript splicing responsible for the generation of its diverse family of protein isoforms. These basic, positively charged polypeptides display spatial and temporal expression patterns consistent with a potential role in the compaction and maintenance of the myelin sheath. MOBP isoforms have also been localized to the nucleus and the microtubular network of oligodendrocytes; transcript corresponding to one isoform is present during embryonic development. Recent reports have identified a role for this protein family in the pathogenesis of multiple sclerosis, but a clear function for the wild‐type protein has remained unclear. We report a detailed analysis of a targeted mutation of Mobp, which results in the deletion of the translational start site and most of the coding sequence of MOBP, and the deletion of the entire coding sequence corresponding to a novel, putative MOBP isoform. Our analyses clearly demonstrate that MOBP‐deficient mice develop normally, generate intact compact CNS myelin, and demonstrate no obvious clinical phenotype. Furthermore, in contrast with another recent study, we find that Mobp null mice demonstrate no significant influence on the axonal diameter of myelinated axons. Although MOBP is not essential for myelination, it appears that its absence is not simply compensated for by increased expression of the “classic” myelin basic protein (MBP). GLIA 39:256–267, 2002. © 2002 Wiley‐Liss, Inc.
Inflammatory mediators increase the expression of nociceptin/orphanin FQ in rat astrocytes in culture
Authors: Buzas Beata , Rosenberger J. , Kim Kee‐Won , Cox Brian M. 
Published: September 2002

AbstractIn the central nervous system, glial cells play an important role in inflammatory and immune responses, and opioid peptides have been identified as essential mediators between the nervous and the immune systems. We report the profound upregulation of the opioid‐related nociceptin/orphanin FQ (N/OFQ) by inflammatory mediators in astrocytes. The bacterial endotoxin, lipopolysaccharide (LPS), and the proinflammatory cytokines, interleukin‐β (IL‐1β) and tumor necrosis factor‐α (TNF‐α), induced levels of N/OFQ mRNA and immunoreactivity. HPLC analysis of the immunoreactivity in astrocyte extracts revealed that a large molecular weight precursor for N/OFQ is being synthesized and released in response to LPS and astrocytes appear to lack the enzymes required to process the precursor protein. Western blot analysis showed that LPS treatment elicited the activation of ERK 1/2 and p38 MAP kinases. Blockade of the p38 or the ERK MAP kinase pathways prevented the LPS‐induced increase in N/OFQ mRNA levels indicating a role for these cascades in the regulation of N/OFQ genes in response to LPS. Regulation of N/OFQ gene expression by ERK and p38 activation may be mediated through the transcription factor CREB. We observed CREB phosphorylation in response to LPS, which was also prevented by SB202190 and PD98059. The NFκB pathway also appears to be involved in the induction of N/OFQ transcription by LPS, since NFκB inhibitors antagonized the effect of LPS on N/OFQ expression. Regulation of N/OFQ by inflammatory mediators in astrocytes may suggest a role for N/OFQ in neural–glial communication and in inflammatory responses in certain neuropathophysiological conditions. GLIA 39:237–246, 2002. Published 2002 Wiley‐Liss, Inc.
Matrix metalloproteinases in neuroinflammation
Authors: Rosenberg Gary A. 
Published: September 2002

AbstractMatrix metalloproteinases (MMPs) are a gene family of neutral proteases that are important in normal development, wound healing, and a wide variety of pathological processes, including the spread of metastatic cancer cells, arthritic destruction of joints, atherosclerosis, and neuroinflammation. In the central nervous system (CNS), MMPs have been shown to degrade components of the basal lamina, leading to disruption of the blood‐brain barrier (BBB), and to contribute to the neuroinflammatory response in many neurological diseases. Brain cells express both constitutive and inducible MMPs in response to cellular stress. MMPs are tightly regulated to avoid unwanted proteolysis. Secreted as inactive enzymes, the MMPs require activation by other proteases and free radicals. The MMPs are part of a larger class of metalloproteinases (MPs), which includes the recently discovered ADAMs (a disintegrin and metalloproteinase domain) and ADAMTS (a disintegrin and metalloproteinase thrombospondin) families. MPs have complex roles at the cell surface and within the extracellular matrix. At the cell surface, they act as sheddases, releasing growth factors, death receptors, and death‐inducing ligands, making them important in cell survival and death. Tissue inhibitors of metalloproteinases (TIMPs) are endogenous inhibitors that regulate the activity of the MMPs. Synthetic inhibitors have been developed for the treatment of arthritis and cancer. These hydroxymate‐based compounds have been shown to reduce injury in experimental allergic encephalomyelitis (EAE), experimental allergic neuritis (EAN), cerebral ischemia, intracerebral hemorrhage, and viral and bacterial infections. MPs have both beneficial and detrimental roles; understanding their expression in various CNS insults will allow for the use of MMP inhibitors in the treatment of neurological disorders. GLIA 39:279–291, 2002. © 2002 Wiley‐Liss, Inc.
Multiple angiotensin receptor subtypes in normal and tumor astrocytes in vitro
Authors: Fogarty David J. , Sánchez‐Gómez M. Victoria , Matute Carlos 
Published: September 2002

AbstractA role for neuropeptide receptors in glial tumorigenesis has recently been proposed. Although angiotensin receptors are known to mediate proliferative effects in many cell types, including brain astrocytes, the possible participation of these receptors in glial tumorigenesis remains unknown. In the present study, we have examined the expression of the molecularly defined angiotensin receptor subtypes AT1a, AT1b, and AT2 in normal perinatal rat astrocytes and in a panel of tumor adult astrocytoma cells, using the reverse transcriptase‐polymerase chain reaction (RT‐PCR). Subsequently, we compared the mitogenic effect of the angiotensins A(1–8), A(2–8), A(3–8) and the heptapeptide “metabolite” A(1–7), on both normal and tumor astrocytes, measured in terms of the incorporation of tritiated thymidine. Our results indicate that AT1a, AT1b, and AT2 angiotensin receptor mRNA is commonly expressed by many of these cells. Of notable exception is the astrocytoma U373 which was not found to express AT1 or AT2 mRNA. Chronic (24‐h) incubation of cells with A(1–8) and A(1–7) lead to the induction of mitogenesis, even in the AT1 and AT2 mRNA negative astrocytoma cell line U373. Moreover, pharmacological analysis indicated that the observed mitogenic effects are not mediated by the AT1 or AT2 type receptors, but rather by a novel, specific A(1–7) angiotensin receptor, since mitogenesis was shown to be partially blocked by the A(1–7) analogue D‐Ala7A(1–7) and by the protease inhibitor orthophenanthroline (100 μM). Using Fura‐2 spectrophotometry, we found that activation of this receptor does not alter intracellular calcium levels; however, preincubation with the protein kinase kinase inhibitor U0126 (10 μM) was found to inhibit these mitogenic effects partially. Overall, these results which demonstrate that normal and tumor astrocytes express a greater variety of angiotensin receptor subtypes than previously thought, support the idea that A(1–7) and its receptor signaling system may play an important role in shaping the astrocyte population during development. Moreover, the untimely expression of this A(1–7) receptor may represent an important etiological component in the development of brain astrocytomas. GLIA 39:304–313, 2002. © 2002 Wiley‐Liss, Inc.
Modulation of activity in temporal cortex during generation of inner speech
Authors: Shergill Sukhwinder S. , Brammer Michael J. , Fukuda Rimmei , Bullmore Ed , Amaro Edson , Murray Robin M. , McGuire Philip K. 
Published: September 2002

AbstractMonitoring one's thoughts (in the verbal modality) is thought to be critically dependent on the interaction between areas that generate and perceive inner speech in the frontal and temporal cortex, respectively. We used functional magnetic resonance imaging (fMRI) to examine the relationship between activity in these areas while the rate of inner speech generation was varied experimentally. The faster rate was associated with activation in the left inferior frontal gyrus, the right pre‐ and postcentral gyri and both superior temporal gyri. Thus, temporal cortical activation was associated with increasing the rate of covert articulation, in the absence of external auditory input, suggesting that there is effective fronto‐temporal connectivity. Furthermore, this may provide support for the existence of feed forward models, which suggest that activity in regions responsible for verbal perception is modulated by activity in areas that generate inner speech. Hum. Brain Mapping 16:219–227, 2002. © 2002 Wiley‐Liss, Inc.
Comparison of spatial normalization procedures and their impact on functional maps
Authors: Crivello Fabrice , Schormann Thorsten , Tzourio‐Mazoyer Nathalie , Roland Per E. , Zilles Karl , Mazoyer Bernard M. 
Published: September 2002

AbstractThe alignment accuracy and impact on functional maps of four spatial normalization procedures have been compared using a set of high resolution brain MRIs and functional PET volumes acquired in 20 subjects. Simple affine (AFF), fifth order polynomial warp (WRP), discrete cosine basis functions (SPM), and a movement model based on full multi grid (FMG) approaches were applied on the same dataset for warping individual volumes onto the Human Brain Atlas (HBA) template. Intersubject averaged structural volumes and tissue probability maps were compared across normalization methods and to the standard brain. Thanks to the large number of degrees of freedom of the technique, FMG was found to provide enhanced alignment accuracy as compared to the other three methods, both for the grey and white matter tissues; WRP and SPM exhibited very similar performances whereas AFF had the lowest registration accuracy. SPM, however, was found to perform better than the other methods for the intra‐cerebral cerebrospinal fluid (mainly in the ventricular compartments). Limited differences in terms of activation morphology and detection sensitivity were found between low resolution functional maps (FWHM ∼10 mm) spatially normalized with the four methods, which overlapped in 42.8% of the total activation volume. These findings suggest that the functional variability is much larger than the anatomical one and that precise alignment of anatomical features has low influence on the resulting intersubject functional maps. When increasing the spatial resolution to approximately 6 mm, however, differences in localization of activated areas appear as a consequence of the different spatial normalization procedure used, restricting the overlap of the normalized activated volumes to only 6.2%. Hum. Brain Mapping 16:228–250, 2002. © 2002 Wiley‐Liss, Inc.
Structural reliability of building blocks in coordination framework design
Authors: Barnett Sarah. A. , Champness Neil R. 
Published: September 2002

AbstractThe use of the building‐block methodology in designing coordination framework materials are discussed, with particular reference to the structural reliability of a given building block. The term structural reliability is defined for a given metal containing moiety as the degree to which that building block reproducibly adopts a given, predicted, coordination arrangement when reacted with a series of chemically related bridging ligands. This terminology is discussed with respect to a range of coordination frameworks constructed using Cd(NO3)2 as a building‐block, which is demonstrated to be structurally unreliable. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:574–577, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10092
Relativistic effects in properties of gold
Authors: Schwerdtfeger Peter 
Published: September 2002

AbstractGold often shows unusual and sometimes surprising chemical and physical properties compared to its lighter group 11 elements (gold anomaly). Pyykkö and coworkers demonstrated in the mid seventies that this is due to effects from special relativity. Recent work in this field indeed indicates that the chemistry and physics of gold is dominated by relativistic effects. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:578–584, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10093
Designer haem proteins: What can we learn from protein engineering?
Authors: Raven Emma Lloyd 
Published: September 2002

AbstractIron protoporphyrin(IX) is one of the most versatile and widespread pieces of catalytic machinery known in biology and is a key component of a multitude of proteins and enzymes. One of most challenging questions in this area has been to identify and understand the relationships that exist between different classes of haem proteins and to use protein engineering methods to rationalize the mechanisms by which the protein structure controls the specific chemical reactivity of the haem group. The application of this approach to the haem enzyme ascorbate peroxidase and the haem protein leghaemoglobin is discussed. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:501–505, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10094
Intermetallic lithium compounds with two‐ and three‐dimensional polyanions—synthesis, structure, and lithium mobility
Authors: Pöttgen Rainer , Wu Zhiyun , Hoffmann Rolf‐Dieter , Kotzyba Gunter , Trill Henning , Senker Jürgen , Johrendt Dirk , Mosel Bernd D. , Eckert H. 
Published: September 2002

AbstractIntermetallic lithium compounds are potential candidates as anode materials for battery applications. We report on the synthesis, crystal structures, and chemical bonding of lithium–transition metal–stannides and indides. These structures are composed of two‐ or three‐dimensionally infinite polyanions formed by the transition metal and tin (indium) atoms. Besides the crystal chemistry we report on magnetic properties, 7Li solid state NMR, and 119Sn Mössbauer spectroscopy data in order to elucidate structure‐property relations for this family of intermetallics. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:506–513, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10095
From heterobimetallic transition metal complexes to linear coordination polymers based on cis‐ and trans‐L2Pt(CCPh)2
Authors: Lang Heinrich , Leschke Marion 
Published: September 2002

AbstractThe reaction of cis‐(2,2′‐bipyridine) Pt(CCPh)2 cis‐(4,4′‐dimethyl‐2,2′‐bipyridine) Pt‐(CCPh)2 and trans‐(Ph3P)2Pt(CCPh)2 towards different group 11 transition‐metal salts [M′X] (M′ = Cu, Ag; X = inorganic ligand) to give heterobimetallic or linear oligomeric and polymeric transition metal complexes is described. Different coordination modes for M′, PhCC, PPh3, and X were found in these species. The structural aspects as well as the preference for one coordination mode over another is discussed. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:521–533, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10097
Organometallic chemistry of silver and copper N‐heterocyclic carbene complexes
Authors: Arnold Polly L. 
Published: September 2002

AbstractThe only stable organometallic carbene complexes of silver and copper are those of N‐heterocyclic carbenes, since formally these robust divalent carbon ligands bind only by a σ donor interaction to the metal. A survey of the range of complexes that have now been reported is presented. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:534–539, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10098
Cyclic polycarbene ligands with crown ether structure
Authors: Hahn F. Ekkehardt , Langenhahn Volker , Le Van Duc , Tamm Matthias , Wittenbecher Lars , Lügger Thomas 
Published: September 2002

AbstractThe cyclization reaction of coordinated β‐functional phenyl isocyanides was used to generate coordinated anellated N‐heterocyclic carbenes. Coordinated 2‐trimethylsiloxyphenyl isocyanide reacts, after SiO bond cleavage, to yield a complex with a coordinated benzoxazol‐2‐ylidene ligand. The cyclization reaction of coordinated 2‐aminophenyl isocyanide, obtained in situ from 2‐azidophenyl isocyanide, yields the coordinated benzimidazol‐2‐ylidene. Both ylidenes can be alkylated at the nitrogen atoms. Attempts to generate four benzimidazol‐2‐ylidenes at PtII and to bridge them by N‐alkylation leading to a crown ether‐like ligand with carbene donors are presented here. Free N‐heterocyclic carbenes derived from benzimidazole with large N‐substituents exist as monomers while they dimerize to dibenzotetraazafulvalenes when substituted with sterically
less‐demanding substituents at the ring nitrogen atoms. A chemical equilibrium between the monomeric carbene and its dimerized enetetraamine exists for the N,N′‐isopropyl substituted derivative. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:540–549, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10099