bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structural integrity and expression of the L3MBTL gene in normal and malignant hematopoietic cells
Authors: MacGrogan Donal , Kalakonda Nagesh , Alvarez Sara , Scandura Joseph M. , Boccuni Piernicola , Johansson Bertil , Nimer Stephen D. 
Published: August 2004

AbstractThe human L3MBTL gene is located in 20q12, a region that is commonly deleted in myeloproliferative disorders (MPD), myelodysplastic syndromes (MDS), and acute myeloid leukemia (AML). L3MBTL is highly homologous to the D‐lethal(3) malignant brain tumor [D‐l(3)mbt] gene, which is a putative tumor‐suppressor gene (TSG) identified in Drosophila and which is closely related to the Drosophila sex combs on midleg (SCM) protein, a member of the Polycomb group (PcG) family of transcriptional repressors. To examine whether L3MBTL functions as a “classic” TSG in human hematologic malignancies, we screened a panel of 17 myeloid leukemia cell lines and peripheral blood or bone marrow samples from 29 MDS and 13 MPD patients for mutations in the entire L3MBTL coding sequence, including intron/exon splice junctions. No mutations were identified, although two single nucleotide differences were found (in intron 14 and in exon 15), which were interpreted as polymorphic changes. We used real‐time RT‐PCR to quantify the level of L3MBTL mRNA in various normal myeloid and lymphoid cell populations. L3MBTL is expressed in normal CD34+ bone marrow cells, and we found that the pattern of L3MBTL expression was similar to that of BMI1, a well‐studied PcG gene with oncogenic activity, suggesting that L3MBTL and BMI1 may be co‐regulated during hematopoiesis. The expression of L3MBTL mRNA in 30 of 35 cell lines and 13 of 15 AML samples was comparable to the level of L3MBTL expression in the normal cell populations. However, five leukemia cell lines showed no L3MBTL expression, and two of the AML samples showed aberrant L3MBTL expression. These data suggest that L3MBTL is not mutated in MDS or MPD. However, given the known dosage effects of PcG proteins in regulating gene expression, reduced or absent L3MBTL expression may be relevant in some cases of myeloid leukemia. © 2004 Wiley‐Liss, Inc.
Various types of rearrangements target TLX3 locus in T‐cell acute lymphoblastic leukemia
Authors: Su Xin Ying , Busson Maryvonne , Della Valle Véronique , Ballerini Paola , Dastugue Nicole , Talmant Pascaline , Ferrando Adolfo A. , Baudry‐Bluteau Dominique , Romana Serge , Berger Roland , Bernard Olivier A. 
Published: August 2004

AbstractMost chromosomal translocations observed in T‐cell acute lymphoblastic leukemia (T‐ALL) often produce transcriptional activation of transcription factor oncogenes. Ectopic expression of the TLX3 (also known as HOX11L2) gene has been shown to be associated with a cryptic t(5;14)(q35;q32) translocation specific for a subtype of T‐ALL. Here we report several examples of variant and alternative translocations resulting in expression of TLX3 in T‐ALL, and we describe three of these translocations in detail. In particular, the CDK6 gene was rearranged in two t(5;7)(q35;q21) translocations. In two additional instances, fusion of the BCL11B (also known as CTIP2) and RANBP17/TLX3 loci were shown to result from subtle genomic insertion/deletion within these loci. This study further underscores that TLX3 expression in T‐ALL is strongly associated with the presence of genomic rearrangements. © 2004 Wiley‐Liss, Inc.
Aberrations of breast cancer susceptibility genes occur early in sporadic breast tumors and in acquisition of breast epithelial immortalization
Authors: Meng Zhen Hang , Ben Yong , Li Zheng , Chew Karen , Ljung Britt‐Marie , Lagios Michael D. , Dairkee Shanaz H. 
Published: August 2004

AbstractIn the search for early deletion targets in sporadic breast cancer, the analysis of TP53, BRCA1, BRCA2, and ATM revealed loss of heterozygosity (LOH) in tumor cells at 1 or more genes in 18 of 24 cases examined. Notably, in more than 60% of such tumors, LOH was detectable in morphologically normal terminal ductal lobular units (TDLUs) adjacent to carcinoma (LOHint). At BRCA2 and ATM, LOHint was most frequent, particularly in TDLUs of women ≤ 50 years old (7 of 10). In a novel preneoplastic model system, declining expression levels observed with increasing passage in culture supported the postulate that during the acquisition of continuous growth, elimination of these genes at an early stage confers a distinct selective advantage. The intimate role of these genes in DNA repair and their early deletion has implications for the possible transforming effects of DNA‐damaging agents on unexcised breast tissue harboring LOHint within breast cancer patients. © 2004 Wiley‐Liss, Inc.
Astrocytic exocytosis vesicles and glutamate: A high‐resolution immunofluorescence study
Authors: Anlauf Enrico , Derouiche Amin 
Published: August 2004

AbstractPhysiological evidence has demonstrated that cultured astrocytes can release glutamate via Ca2+‐dependent mechanisms. Also, glutamate released from astrocytes in the hippocampal slice interferes with synaptic neurotransmission. Since these observations suggest vesicular glutamate release from astrocytes, the presence of glutamate‐containing exocytosis vesicles was investigated. We applied immunofluorescence techniques combined with high‐performance deconvolution microscopy, which yields a resolution of <200 nm and permits evaluation of double labeling in individual vesicles. Using a well‐characterized anti‐glutamate antiserum and parameters minimizing fixative‐induced autofluorescence, glutamate‐immunoreactive (ir) puncta were found all over the astrocyte but were conspicuously dense at the cell boundary and in filopodia. Images were very similar with antibodies against vesicular glutamate transporters (vGluT1 and vGluT2). Labeling for the exocytosis markers rab3, synaptophysin, or synaptobrevin was also punctate, particularly dense at the cell boundary, but disappearing toward the perinuclear region. Sections of the cell boundary were delineated by rab3 immunoreactivity. In double‐labeled cells, vesicular colocalization of glutamate and any of the exocytosis markers was frequent in filopodia and at the cell boundary. Within the cell, single‐labeled glutamate‐ir vesicles prevailed; double‐labeled vesicles were infrequently present. By resolving single vesicles, in cultured astrocytes we visualize glutamate‐containing vesicles, vesicles displaying vGluT1 or vGluT2, and exocytosis vesicles displaying glutamate‐ir. This may provide the morphological correlate of Ca2+‐dependent glutamate release from astrocytes, possibly occurring at defined sections of the cell membrane and at filopodia. However, since vGluTs and exocytosis markers are classically restricted to nerve terminals in the CNS, glutamate release from astrocytes in the CNS remains to be studied. © 2004 Wiley‐Liss, Inc.
Root growth and soil water utilization of winter wheat in the North China Plain
Authors: Zhang Xiying , Pei Dong , Chen Suying 
Published: August 2004

AbstractWinter wheat (Triticum aestivum L.) is the major crop in the North China Plain (NCP). The monsoon climate in this region causes most rain to fall in the summer season, but during the winter‐wheat growing season (October–May) the rainfall is far less than the water requirements for the crop. The efficiency of soil water use by winter wheat needs to be improved to reduce the need for irrigation. In this paper, we report the results of two seasons' work on soil water utilization, root growth and distribution, root water uptake by the crop under different irrigation treatments, and possible ways to improve soil water‐use efficiency. The field experiments were carried out at Luancheng Station (37° 53′N, 114° 41′E) from 1996 to 1997 and 1998 to 1999, two growing seasons of winter wheat. Five treatments for each season: rain‐fed and irrigated winter wheat with different irrigation numbers from 1 up to 4, were set up in a randomized plot design. Soil available water‐holding capacity at the experimental site was about 454 mm for the top 2 m soil profile. Root sampling results showed that winter wheat had a prolific root system with an average maximum rooting depth of 2 m. Most of the root system was concentrated in the upper 40 cm of soil. Root length density in the top layer of soil (0–20 cm) was very high, with values over 5 cm cm−3. The distribution of water uptake from the soil profile under high soil moisture conditions was the same as the distribution of root length density. The roots in the top layer of soil played an important role in soil water uptake. When root length density was less than 0 · 8 cm cm−3, the root was the main factor limiting the complete utilization of soil water by crops. The scarcity of roots in the deep soil layers restricted the full utilization of soil water by the crops. Thus, at maturity, over 100 mm of available water remained in the root zone for the rain‐fed treatment, although the upper layers had already entered water deficit. The crop took up 80% of the total available soil water in the treatment without irrigation in a dry season. For irrigated wheat, from 40 to 50% of crop water uptake was from the stored soil water. Available stored soil water played an important role in the higher production of wheat crops in the NCP. Effective measures to increase the utilization of stored soil water could improve crop performance under conditions of limited water supply. Results showed that deep tillage to break the soil pan improved root growth in the deeper soil layers, and sowing the crop evenly also enhanced water uptake from the top soil layer to compete with soil evaporation. Copyright © 2004 John Wiley & Sons, Ltd.
Changes in components of the hydrological cycle in the Yellow River basin during the second half of the 20th century
Authors: Liu Changming , Zheng Hongxing 
Published: August 2004

AbstractThe Yellow River basin of China, located in the semi‐humid, semi‐arid and arid climatic zones, is now confronted with serious problems of water deficit. With regard to intensified human activities and climatic change, knowledge about changes in the regional hydrological cycle should be seen as a key requirement in searching for an adaptation strategy in water resource use. This paper attempts to detect trends associated with hydrological cycle components in the region. The hydrological cycle components are derived from monthly precipitation and runoff date, based on the schemes proposed herein. Two methods, including linear regression and Mann–Kendall, have been applied to the detection of trends in the hydrological cycle components. For the Lanzhou station, only surface runoff showed a decreasing trend. As for Huayuankou station, the results have shown that natural runoff, surface runoff and groundwater runoff all have significant decreasing trends, whereas the decreasing trend of the other components is not significant. Impacts of human activities, climatic change and annual runoff coefficient change on the hydrological cycle components are also discussed. The study suggests that increasing water resources development and utilization is the most important factor in causing the frequent drying‐up in the main course of the Yellow River. Moreover, the similarities of the trends in precipitation and natural runoff suggest a linkage between climatic change and hydrological cycle change. Copyright © 2004 John Wiley & Sons, Ltd.
Predictor relevance and extramarital affairs
Authors: Li QI , Racine Jeff 
Published: August 2004

AbstractWe revisit Fair's (1978) ‘theory of extramarital affairs’ using robust nonparametric methods developed for the analysis of categorical data. We find evidence suggesting that the number of years married is not a relevant predictor of the propensity to engage in extramarital affairs having controlled for other factors. This finding runs counter to the prevailing wisdom gleaned from misspecified parametric models. Copyright © 2004 John Wiley & Sons, Ltd.
Nonparametric analysis of returns to scale in the US hospital industry
Authors: Wilson Paul W. , Carey Kathleen 
Published: August 2004

AbstractThis paper presents new estimates of scale economies for US hospitals. We show that the common translog specification of hospital costs is a misspecification, and employ nonparametric, local linear estimation with both continuous and discrete covariates. A bootstrap method is used to provide inferences regarding ray scale economies and expansion path scale economies for a large sample of hospitals covering 1984–1996. We find evidence of changes in the structure of hospital costs over the sample period, as well as evidence of locally optimal hospital sizes. Copyright © 2004 John Wiley & Sons, Ltd.
Antibacterial activity of cloth functionalized with N‐alkylated poly(4‐vinylpyridine)
Authors: Cen L. , Neoh K. G. , Kang E. T. 
Published: August 2004

AbstractA simple technique was developed to functionalize the surface of commercial cotton cloth with bactericidal polycationic groups. The cloth was first graft copolymerized with 4‐vinylpyridine (4VP) and subsequently derivatized with hexylbromide via the quaternization of the grafted pyridine groups into pyridinium groups. X‐ray photoelectron spectroscopy (XPS) was used to characterize the cotton cloth after each surface functionalization step. The pyridinium groups introduced on the substrate surface exhibited a high bacterial killing efficiency as shown by airborne and waterborne Escherichia coli (E. coli) assays, as well as a test to measure the number of viable E. coli cells in suspension upon contact with the cloth. This antibacterial property is preserved even after the cloth is subjected to prolonged weathering under UV irradiation and water spray. Wild‐type bacteria were also cultured from soil and used to verify the antibacterial potential of the functionalized cloth. The inhibition of biofilm formation on the functionalized cloth was observed even with the inoculation of high concentrations of microorganisms. The success of the present surface functionalization technique as applied to cloth is a promising development, as since cloth is a common material having wide applications. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 71A: 70–80, 2004
ABT1‐associated protein (ABTAP), a novel nuclear protein conserved from yeast to mammals, represses transcriptional activation by ABT1
Authors: Oda Tsukasa , Fukuda Aya , Hagiwara Hiroko , Masuho Yasuhiko , Muramatsu Masa‐aki , Hisatake Koji , Yamashita Takayuki 
Published: August 2004

AbstractVarious TATA‐binding protein (TBP)‐associated proteins are involved in the regulation of gene expression through control of basal transcription directed by RNA polymerase (Pol) II. We recently identified a novel nuclear protein, activator of basal transcription 1 (ABT1), which binds TBP and DNA, and enhances Pol II‐directed basal transcription. To better understand regulatory mechanisms for ABT1, we searched for ABT1‐binding proteins using a yeast two‐hybrid screening and isolated a cDNA clone encoding a novel protein termed ABT1‐associated protein (ABTAP). ABTAP formed a complex with ABT1 and suppressed the ABT1‐induced activation of Pol II‐directed transcription in mammalian cells. Furthermore, ABTAP directly bound to ABT1, disrupted the interaction between ABT1 and TBP, and suppressed the ABT1‐induced activation of Pol II‐directed basal transcription in vitro. These two proteins colocalized in the nucleolus and nucleoplasm and were concomitantly relocalized into discrete nuclear bodies at higher expression of ABTAP. Taken together, these results suggest that ABTAP binds and negatively regulates ABT1. The ABT1/ABTAP complex is evolutionarily conserved and may constitute a novel regulatory system for basal transcription. © 2004 Wiley‐Liss, Inc.
Differential regulation of platelet‐derived growth factor stimulated migration and proliferation in osteoblastic cells
Authors: Mehrotra Meenal , Krane Stephen M. , Walters Kristen , Pilbeam Carol 
Published: August 2004

AbstractOsteoblastic migration and proliferation in response to growth factors are essential for skeletal development, bone remodeling, and fracture repair, as well as pathologic processes, such as metastasis. We studied migration in response to platelet‐derived growth factor (PDGF, 10 ng/ml) in a wounding model. PDGF stimulated a twofold increase in migration of osteoblastic MC3T3‐E1 cells and murine calvarial osteoblasts over 24–48 h. PDGF also stimulated a tenfold increase in 3H‐thymidine (3H‐TdR) incorporation in MC3T3‐E1 cells. Migration and DNA replication, as measured by BrdU incorporation, could be stimulated in the same cell. Blocking DNA replication with aphidicolin did not reduce the distance migrated. To examine the role of mitogen‐activated protein (MAP) kinases in migration and proliferation, we used specific inhibitors of p38 MAP kinase, extracellular signal regulated kinase (ERK), and c‐Jun N‐terminal kinase (JNK). For these signaling studies, proliferation was measured by carboxyfluorescein diacetate succinimidyl ester (CFSE) using flow cytometry. Inhibition of the p38 MAP kinase pathway by SB203580 and SB202190 blocked PDGF‐stimulated migration but had no effect on proliferation. Inhibition of the ERK pathway by PD98059 and U0126 inhibited proliferation but did not inhibit migration. Inhibition of JNK activity by SP600125 inhibited both migration and proliferation. Hence, the stimulation of migration and proliferation by PDGF occurred by both overlapping and independent pathways. The JNK pathway was involved in both migration and proliferation, whereas the p38 pathway was predominantly involved in migration and the ERK pathway predominantly involved in proliferation. © 2004 Wiley‐Liss, Inc.
Constitutive association of cell surface CCR5 and CXCR4 in the presence of CD4
Authors: Wang Jinhai , Alvarez Raymond , Roderiquez Gregory , Guan Ennan , Norcross Michael A. 
Published: August 2004

AbstractChemokine receptors CCR5 and CXCR4 are the major coreceptors of HIV‐1 infection and also play fundamental roles in leukocyte trafficking, metastasis, angiogenesis, and embyogenesis. Here, we show that transfection of CCR5 into CXCR4 and CD4 expressing 3T3 cells enhances the cell surface level of CXCR4. In CCR5 high expressing cells, cell surface level of CXCR4 was incompletely modulated in the presence of the CXCR4 ligand CXCL12/SDF‐1α. CCR5 was resistant to ligand‐dependent modulation with the CCR5 ligand CCL5/RANTES. Confocal laser microscopy revealed that CCR5 was colocalized with CXCR4 on the cell surface. In CD4 expressing CCR5 and CXCR4 double positive NIH 3T3 cells, immunoprecipitation followed by Western blot analysis revealed that CCR5 was associated with CXCR4 and CD4. CXCR4 and CCR5 were not co‐immunoprecipitated in cells expressing CCR5 and CXCR4 but without CD4 expression. Compared to NIH 3T3CD4 cells expressing CXCR4, the entry of an HIV‐1 X4 isolate (HCF) into NIH 3T3CD4 expressing both CXCR4 and CCR5 was reduced. Our data indicate that chemokine receptors interact with each other, which may modulate chemokine–chemokine receptor interactions and HIV‐1 coreceptor functions. Published 2004 Wiley‐Liss, Inc.
Stretch‐induced phosphorylation of ERK1/2 depends on differentiation stage of osteoblasts
Authors: Jansen J.H.W. , Weyts F.A.A. , Westbroek I. , Jahr H. , Chiba H. , Pols H.A.P. , Verhaar J.A.N. , van Leeuwen J.P.T.M. , Weinans H. 
Published: August 2004

AbstractThe goal of this study was to investigate the effect of mechanical loading on osteoblasts and extracellular signal‐regulated kinase (ERK1/2) signaling in relation to osteoblast differentiation and mineralization. A human osteoblast cell line (SV‐HFO) was triggered to differentiate to the advanced state of mineralization by addition of the osteogenic factors dexamethasone and β‐glycerophosphate. Osteoblasts were subjected to cyclic, equibiaxial stretch for 5, 15, or 60 min at different stages of differentiation (days 7, 14, and 21). Baseline (static) phosphorylated ERK1/2 and total ERK1/2 levels gradually increased during osteoblast differentiation. Cyclic stretch induced a rapid increase in ERK1/2 phosphorylation with a maximum between 5 and 15 min. Prolonged stretching for 60 min resulted in a decrease of phosphorylated ERK1/2 towards baseline level, suggesting a desensitization mechanism. The effect of stretch on ERK1/2 phosphorylation was strongest at later stages of differentiation (days 14 and 21). At day 21, the increase of ERK1/2 phosphorylation in response to stretch was significantly lower in non‐differentiating than in differentiating osteoblasts. This could not be explained by differences in cell density, but did correlate with the formation of extracellular matrix, collagen fibrils. Mineralization of the extracellular matrix did not lead to a further increase of ERK1/2 phosphorylation. In conclusion, the current study demonstrates that the extent of activation of the ERK1/2 pathway is dependent on the differentiation or functional stage of the osteoblast. The presence of an extracellular matrix, but not per se mineralization, seems to be the predominant determinant of osteoblastic response to strain. © 2004 Wiley‐Liss, Inc.
Temporal expression changes during differentiation of neural stem cells derived from mouse embryonic stem cell
Authors: Ahn Joon‐Ik , Lee Ki‐Hwan , Shin Dong‐Mi , Shim Jae‐Won , Kim Chang‐mee , Kim Hyun , Lee Sang‐Hun , Lee Yong‐Sung 
Published: August 2004

AbstractTemporal analysis in gene expression during differentiation of neural stem cells (NSCs) was performed by using in‐house microarrays composed of 10,368 genes. The changes in mRNA level were measured during differentiation day 1, 2, 3, 6, 12, and 15. Out of 10,368 genes analyzed, 259 genes were up‐regulated or down‐regulated by 2‐fold or more at least at one time‐point during differentiation, and were classified into six clusters based on their expression patterns by K‐means clustering. Clusters characterized by gradual increase have large numbers of genes involved in transport and cell adhesion; those which showed gradual decrease have much of genes in nucleic acid metabolism, cell cycle, transcription factor, and RNA processing. In situ hybridization (ISH) validated microarray data and it also showed that Fox M1, cyclin D2, and CDK4 were highly expressed in CNS germinal zones and ectonucleotide pyrophosphatase/phosphodiesterase 2 (Enpp2) was highly expressed in choroid plexus where stem/progenitor cells are possibly located. Together, this clustering analysis of expression patterns of functionally classified genes may give insight into understanding of CNS development and mechanisms of NSCs proliferation and differentiation. © 2004 Wiley‐Liss, Inc.