bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reduced Mcm2 Expression Results in Severe Stem/Progenitor Cell Deficiency and Cancer
Authors: Pruitt Steven C. , Bailey Kimberly J. , Freeland Amy 
Published: August 2007

Abstract
Mcm2 is a component of the DNA replication licensing complex that marks DNA replication origins during G1 of the cell cycle for use in the subsequent S-phase. It is expressed in stem/progenitor cells in a variety of regenerative tissues in mammals. Here, we have used the Mcm2 gene to develop a transgenic mouse in which somatic stem/progenitor cells can be genetically modified in the adult. In these mice, a tamoxifen-inducible form of Cre recombinase is integrated 3′ to the Mcm2 coding sequence and expressed via an internal ribosome entry site (IRES). Heterozygous Mcm2IRES-CreERT2/wild-type (wt) mice are phenotypically indistinguishable from wild-type at least through 1 year of age. In bigenic Mcm2IRES-CreERT2/wt; Z/EG reporter mice, tamoxifen-dependent enhanced green fluorescence protein expression is inducible in a wide variety of somatic stem cells and their progeny. However, in Mcm2IRES-CreERT2/IRES-CreERT2 homozygous embryos or mouse embryonic fibroblasts, Mcm2 is reduced to approximately one-third of wild-type levels. Despite the fact that these mice develop normally and are asymptomatic as young adults, life span is greatly reduced, with most surviving to only ∼10–12 weeks of age. They demonstrate severe deficiencies in the proliferative cell compartments of a variety of tissues, including the subventricular zone of the brain, muscle, and intestinal crypts. However, the immediate cause of death in most of these animals is cancer, where the majority develop lymphomas. These studies directly demonstrate that deficiencies in the function of the core DNA replication machinery that are compatible with development and survival nonetheless result in a chronic phenotype leading to stem cell deficiency in multiple tissues and cancer.
Disclosure of potential conflicts of interest is found at the end of this article.
A Novel Role of Complement in Mobilization: Immunodeficient Mice Are Poor Granulocyte-Colony Stimulating Factor Mobilizers Because They Lack Complement-Activating Immunoglobulins
Authors: Reca Ryan , Cramer Daniel , Yan Jun , Laughlin Mary J. , Janowska-Wieczorek Anna , Ratajczak Janina , Ratajczak Mariusz Z. 
Published: August 2007

AbstractComplement (C) and innate immunity emerge as important and underappreciated modulators of mobilization of hematopoietic stem/progenitor cells (HSPC). We reported that (a) C becomes activated in bone marrow (BM) during granulocyte–colony-stimulating factor (G-CSF)-induced mobilization by the classic immunoglobulin (Ig)-dependent pathway and that (b) C3 cleavage fragments increase the responsiveness of HSPC to a stromal derived factor-1 gradient. Since patients suffering from severe combined immunodeficiency (SCID) mobilize poorly, we hypothesized that this could be directly linked to the lack of C activating Ig in these patients. In the current study to better elucidate the role of C activation in HSPC mobilization, we mobilized mice that lack Ig (RAG2, SCID, and Jh) by G-CSF or zymosan, compounds that activate C by the classic Ig-dependent and the alternative Ig-independent pathways, respectively. In addition, we evaluated mobilization in C5-deficient animals. Mobilization was evaluated by measuring the number of colony-forming unit-granulocyte macrophage and leukocytes circulating in peripheral blood. We found that (a) G-CSF- but not zymosan-induced mobilization was severely reduced in RAG2, SCID, and Jh mice; (b) impaired G-CSF-induced mobilization was restored after infusion of purified wild-type Ig; and (c) mobilization was severely reduced in C5-deficient mice. These data provide strong evidence that the C system plays a pivotal role in mobilization of HSPC and that egress of HSPC from BM occurs as part of an immune response.Disclosure of potential conflicts of interest is found at the end of this article.
Tectono-biosedimentary recordings at the Lias-Dogger transition: example of the Quercy carbonate platform (Aquitaine Basin, France)
Authors: Lezin Carine , Rey Jacques , Faure Philippe , Cubaynes René , Pelissie Thierry , Durlet Christophe , Deconinck Jean-François 
Published: August 2007

AbstractOn the eastern edge of the Aquitaine Basin, the Lias-Dogger transition and the events, which occurred during this time interval are studied in the Quercy sedimentary basin. Stratigraphic correlations are proposed using a biochronological calibration based on the determination of numerous ammonites and brachiopods. Facies analyses using statistical processing integrate the presence of faults and tectonic compartments and lead to reconstruction of palaeoenvironments in space and time. The paper includes the description of system tracts following Haq et al. [1987] and Vail et al. [1991], and twelve palaeogeographic maps of the area studied. The objectives are to distinguish the various allocyclic and autocyclic factors controlling sedimentation and to show the impact of the Mid-Cimmerian tectonic event on the evolution of the basin.
Turtles from the late Eocene – early Oligocene of the Krabi Basin (Thailand)
Authors: Claude Julien , Suteethorn Varavudh , Tong Haiyan 
Published: August 2007

AbstractTwo new species of geoemydid turtles from the late Eocene – early Oligocene of Krabi Basin in southern peninsula of Thailand are described on the basis of shells and other postcranial material: Mauremys thanhinensis n. sp. and Hardella siamensis n. sp. These early representatives of testudinoid turtles from South-East Asia shed light on the early evolution of extant geoemydids.
Incretin Receptors for Glucagon-Like Peptide 1 and Glucose-Dependent Insulinotropic Polypeptide Are Essential for the Sustained Metabolic Actions of Vildagliptin in Mice
Authors: Flock Grace , Baggio Laurie L. , Longuet Christine , Drucker Daniel J. 
Published: August 2007

OBJECTIVE—Dipeptidyl peptidase-4 (DPP4) inhibitors lower blood glucose in diabetic subjects; however, the mechanism of action through which these agents improve glucose homeostasis remains incompletely understood. Although glucagon-like peptide (GLP)-1 and glucose-dependent insulinotropic polypeptide (GIP) represent important targets for DPP4 activity, whether additional substrates are important for the glucose-lowering actions of DPP4 inhibitors remains uncertain.
RESEARCH DESIGN AND METHODS—We examined the efficacy of continuous vildagliptin administration in wild-type (WT) and dual incretin receptor knockout (DIRKO) mice after 8 weeks of a high-fat diet.
RESULTS—Vildagliptin had no significant effect on food intake, energy expenditure, body composition, body weight gain, or insulin sensitivity in WT or DIRKO mice. However, glycemic excursion after oral glucose challenge was significantly reduced in WT but not in DIRKO mice after vildagliptin treatment. Moreover, vildagliptin increased levels of glucose-stimulated plasma insulin and reduced levels of cholesterol and triglycerides in WT but not in DIRKO mice. Vildagliptin treatment reduced the hepatic expression of genes important for cholesterol synthesis and fatty acid oxidation, including phospho-mevalonate kinase (Mvk), acyl-coenzyme dehydrogenase medium chain (Acadm), mevalonate (diphospho)decarboxylase (Mvd), and Acyl-CoA synthetase (Acsl1), in WT but not in DIRKO mice. However, vildagliptin also reduced levels of hepatic mRNA transcripts for farnesyl di-phosphate transferase (Fdft1), acetyl coenzyme A acyltransferase 1 (Acaa1), and carnitine palmitoyl transferase 1 (Cpt 1) in DIRKO mice. No direct effect of GLP-1 receptor agonists was detected on cholesterol or triglyceride synthesis and secretion in WT hepatocytes.
CONCLUSIONS—These findings illustrate that although GLP-1 and GIP receptors represent the dominant molecular mechanisms for transducing the glucoregulatory actions of DPP4 inhibitors, prolonged DPP4 inhibition modulates the expression of genes important for lipid metabolism independent of incretin receptor action in vivo.
A Thermoplastic Gel Electrolyte for Stable Quasi‐Solid‐State Dye‐Sensitized Solar Cells
Authors: Wu J. H. , Hao S. C. , Lan Z. , Lin J. M. , Huang M. L. , Huang Y. F. , Fang L. Q. , Yin S. , Sato T. 
Published: August 2007

AbstractDye‐sensitized solar cells (DSSCs) are receiving considerable attention as low‐cost alternatives to conventional solar cells. In DSSCs based on liquid electrolytes, a photoelectric efficiency of 11 % has been achieved, but potential problems in sealing the cells and the low long‐term stability of these systems have impeded their practical use. Here, we present a thermoplastic gel electrolyte (TPGE) as an alternative to the liquid electrolytes used in DSSCs. The TPGE exhibits a thermoplastic character, high conductivity, long‐term stability, and can be prepared by a simple and convenient protocol. The viscosity, conductivity, and phase state of the TPGE can be controlled by tuning the composition. Using 40 wt % poly(ethylene glycol) (PEG) as the polymeric host, 60 wt % propylene carbonate (PC) as the solvent, and 0.65 M KI and 0.065 M I2 as the ionic conductors, a TPGE with a conductivity of 2.61 mS cm–2 is prepared. Based on this TPGE, a DSSC is fabricated with an overall light‐to‐electrical‐energy conversion efficiency of 7.22 % under 100 mW cm–2 irradiation. The present findings should accelerate the widespread use of DSSCs.
Insight into Doping Effects in Apatite Silicate Ionic Conductors
Authors: Tolchard J. R. , Slater P. R. , Islam M. S. 
Published: August 2007

AbstractNovel apatite‐type silicates are attracting considerable interest as a new family of oxide‐ion conductors with potential use in fuel cells and ceramic membranes. Combined computer modeling and X‐ray absorption (EXAFS) techniques have been used to gain fresh insight, at the atomic level, into the site selectivity and local structures of a wide range of dopants in these apatite materials. The results indicate that an unusually broad range of dopant ions (in terms of size and charge state) can substitute for La in the La9.33Si6O26 apatite, in accord with current experimental data. The range is much wider than that observed for doping on a single cation site in most other oxide‐ion conductors, such as the perovskite LaGaO3. In addition, our local structural investigation demonstrates that this dopant behavior is related to the flexibility of the silicate substructure, which allows relatively large local distortion and alteration of the site volumes. This could be a key factor in the high oxide‐ion conductivity exhibited by these apatite silicates. Indeed, the breadth of possible doping regimes in these novel materials provides new opportunities to design and optimize the conduction properties for fuel cell electrolytes.
Photoelectrical Characteristics of a C/CNx Multiwalled Nanotube
Authors: Xiao K. , Fu Y. , Liu Y. Q. , Yu G. , Zhai J. , Jiang L. , Hu W. P. , Shuai Z. G. , Luo Y. , Zhu D. B. 
Published: August 2007

AbstractA nanotube diode fabricated from a single C/CNx multiwalled nanotube exhibits a large photocurrent and a large photovoltage under illumination. The current–voltage (I–V) characteristics of the diode indicate a clear rectification effect. By comparing the I–V characteristics of C, CNx, and C/CNx nanotube diodes, we show that the rectifying characteristics of the C/CNx diode arises from the molecular junction formed at the C/CNx interface where the C and CNx segments are chemically bonded. External radiation photochemically generates electrons and holes in the C/CNx nanotube, producing a large photocurrent because of the influence of the strong electric field in the vicinity of the C/CNx junction. These unique photoresponsive characteristics of C/CNx nanotube junction diodes points to potential applications such as photovoltaic devices and photodiodes.
Ortho‐Nitrostilbenes in Polycarbonate for Holographic Data Storage
Authors: Erben C. , Boden E. P. , Longley K. L. , Shi X. , Lawrence B. L. 
Published: August 2007

AbstractHolographic data storage materials based on dye‐doped polycarbonate that could find application in professional archival and consumer applications are described. The dyes are selected from the class of o‐nitrostilbenes, which irreversibly bleach under exposure to light and show high thermal stability before and after exposure. The reduction in concentration of the dye in the host after exposure induces refractive index variations over a wide range of wavelengths and extends well away from the dye absorption peak conforming to the Kramers–Kronig relationship. The materials are injection moldable into the standard disc format and have negligible shrinkage during data storage. Samples were produced using different dyes and various concentrations in a polycarbonate host and processed on professional CD/DVD equipment. The refractive index change is as high as 0.04, with a measured instantaneous sensitivity of 0.5 cm J–1 and M/# = 0.3.
Sulfur‐Functionalized Mesoporous Carbon
Authors: Shin Y. , Fryxell G. E. , Um W. , Parker K. , Mattigod S. V. , Skaggs R. 
Published: August 2007

AbstractA simple synthesis route to mesoporous carbons that contain heteroaromatic functionality is described. The sulfur‐functionalized mesoporous carbon (S‐FMC) materials that have been prepared show excellent thermal stability, as well as excellent hydrothermal stability, and stability over a wide range of pH values. These materials also show excellent mercury sorption performance over a broad range of pH, much broader than is possible with thiol‐based functionality or most silica‐based sorbents. The superior performance of these mesoporous heterocarbons as heavy‐metal sorbent material is demonstrated. These materials are shown to be stable at elevated temperatures and extreme pHs, making them ideally suited as a new class of absorbent material.
Selective Crystallization of Organic Semiconductors on Patterned Templates of Carbon Nanotubes
Authors: Liu S. , Briseno A. L. , Mannsfeld S. C. B. , You W. , Locklin J. , Lee H. W. , Xia Y. , Bao Z. 
Published: August 2007

AbstractA method of patterning large arrays of organic single crystals is reported. Using single‐walled carbon nanotube (SWNT) bundles as patterned templates, several organic semiconductor materials were successfully patterned, including p‐type pentacene, tetracene, sexiphenylene, and sexithiophene, as well as n‐type tetracyanoquinodimethane (TCNQ). This study suggests that the selective growth of crystals onto patterned carbon nanotubes is most likely due to the coarse topography of the SWNT bundles. Moreover, we observed that the crystals nucleated from SWNT bundles and grew onto SWNT bundles in a conformal fashion. The dependence of the number of crystals on the quantity of SWNT bundles is also discussed. The crystal growth can be directly applied onto transistor source‐drain electrodes and arrays of organic single‐crystal field effect transistors are demonstrated. The results demonstrate the potential of utilizing carbon nanotubes as nucleation templates for patterning a broad range of organic materials for applications in optoelectronics.
Monitoring serum hepatitis C virus (HCV) RNA in patients with HCV‐infected CD20‐positive B‐cell lymphoma undergoing rituximab combination chemotherapy
Authors: Ennishi Daisuke , Terui Yasuhito , Yokoyama Masahiro , Mishima Yuko , Takahashi Shunji , Takeuchi Kengo , Okamoto Hiroaki , Tanimoto Mitsune , Hatake Kiyohiko 
Published: August 2007

AbstractSeveral studies have shown that the frequency of hepatitis C virus (HCV) infection is high in patients with B‐cell non‐Hodgkin's lymphoma (NHL). In these studies, liver dysfunction during chemotherapy has been demonstrated, but changes in HCV ribonucleic acid (RNA) levels during chemotherapy have not been well documented. In this study, we monitored serum HCV RNA levels and liver function in five HCV‐infected patients with B‐cell NHL undergoing treatment with rituximab‐combination chemotherapy. Increased HCV RNA levels during or after the chemotherapy were observed in all five patients, and a significant increase in transaminases was seen in one case. In this case, serum HCV RNA level dramatically decreased at the time of the increase of transaminases, and this suggested that the cause of liver damage was an immune reaction against hepatocytes with HCV and not any anticancer drug induced liver toxicity. Monitoring of serum HCV RNA levels and transaminases may be helpful to understand the cause of liver dysfunction in patients receiving chemotherapy. However, increases of HCV viral load were not associated with the occurrence of liver dysfunction in this study. Further studies will be necessary to investigate more fully the relationship between changes in HCV viral load and liver function during chemotherapy for HCV‐infected patients. Am. J. Hematol., 2008. © 2007 Wiley‐Liss, Inc.
Comparison of gene expression profiles in erythroid‐like cells derived from mouse embryonic stem cells differentiated in simple and co‐culture systems
Authors: Boroujeni Mandana B. , Salehnia Mojdeh , Valojerdi Mojtaba R. , Mowla Seyed J. , Forouzandeh Mehdi , Hajizadeh Ebrahim 
Published: August 2007

AbstractThe feeder layer and the presence of specific growth factors are thought to induce the differentiation of embryonic stem cells (ESCs) in culture. The aim of this study was to evaluate the effect of erythropoietin (EPO) on the differentiation of ESCs into erythroid colonies in simple and co‐culture systems. Embryoid bodies were dissociated and replated in semisolid medium in simple culture or in a co‐culture system with bone‐marrow stromal cells (BMSCs), both in the presence or absence of EPO. Colony assays, benzidine staining, and ultrastructural studies were carried out until day 10 of culture. Expression of the ε globin, βH1 globin, runt‐related transcription factor 1 (RUNX1), βmajor globin, and erythropoietin receptor (EPOR) genes was evaluated using semi‐quantitative RT‐PCR. A comparison with the corresponding controls showed that colony size increased in both systems (P ≤≤ 0.05). The number of benzidine‐positive colonies in the co‐culture system with EPO (86.6 ± 17.86) was significantly different compared to the simple culture system with EPO (43.6 ± 4.77; P ≤≤ 0.05). The hemoglobin content of the differentiated cells was visualized in micrographs. Analysis of gene expression showed that all genes except βmajor globin were expressed in the simple culture system, whereas in the co‐culture system all genes were expressed. These results confirmed that the presence of EPO in a BMSC co‐culture system with ESCs improves the differentiation of ESCs to erythroid colonies. Moreover, evidence of primitive and definitive erythropoiesis was observed in this co‐culture system. Am. J. Hematol., 2008. © 2007 Wiley‐Liss, Inc.
A novel ϵγδβ thalassemia of 1.4 Mb deletion found in a Japanese patient
Authors: Furuya Chiemi , Yamashiro Yasuhiro , Hattori Yukio , Hino Minako , Nishioka Hiroko , Shimizu Yoshihisa , Okano Kozue , Horibe Keizou 
Published: August 2007

AbstractA novel large deletion, causing ϵγδβ thalassemia (here called, ϵγδβ thalassemia Jpn‐I) was discovered in a 6‐year‐old Japanese boy. He was born uneventfully, but revealed thalassemia minor after birth. The mutation was inherited from his mother. The deletion, caused by an illegitimate recombination extended from 750 kb upstream to 660 kb downstream of e‐globin gene, and removed about 1.4 Mb of DNA, the largest in ϵγδβ thalassemias. A 19‐nucleotide orphan sequence and direct repeats were present at the junction. The deletion lost several functional genes, but no relevant symptoms manifested. The breakpoints were determined by relatively simple methods. Am. J. Hematol., 2008. © 2007 Wiley‐Liss, Inc.
Cardiovascular fitness in adolescents: The influence of sexual maturation status—The AVENA and EYHS studies
Authors: Ortega Francisco B. , Ruiz Jonatan R. , Mesa Jose L. , Gutiérrez Ángel , Sjöström Michael 
Published: August 2007

AbstractThe purposes were: (1) to determine the influence of sexual maturation status and body composition by comparing cardiovascular fitness (CVF) level in two adolescent populations from the south and the north of Europe; (2) to describe the associations between CVF and sexual maturation status in adolescence. A total of 1,867 Spanish adolescents from the AVENA study and 472 from the Swedish part of the EYHS were selected for this report (aged 14–16 years). CVF (expressed by the maximal oxygen consumption) was estimated from 20 m shuttle run test in the AVENA study and from a maximal ergometer cycle test in the EYHS. Sexual maturation status was classified according to Tanner stages. Body fat percentage (BF%) was estimated from skinfold thicknesses. Expressing CVF in different ways (in absolute value and in relation to weight or fat free mass; FFM) resulted in two different results with regard to CVF interpretation and comparison between the study populations. A higher CVF, as expressed in relation to FFM, was observed in the Spanish when compared to Swedish adolescents (P = 0.001). However, after adjusting for both sexual maturation status and BF%, the difference disappeared in males, while it remained significant in females (P = 0.001). CVF was negatively associated with sexual maturation status in males (P = 0.001). However, after adjusting for BF%, the association disappeared in males, while it was significant in females (P = 0.05). These results suggest that for CVF comparisons and interpretation in adolescent populations, sexual maturation status and BF%, as well as the way to express the CVF, should be taken into account. Am. J. Hum. Biol., 2007. © 2007 Wiley‐Liss, Inc.
The African contribution to the present‐day population of the Azores Islands (Portugal): Analysis of the Y chromosome haplogroup E
Authors: Neto Domingos , Montiel Rafael , Bettencourt Conceição , Santos Cristina , Prata Maria J. , Lima Manuela 
Published: August 2007

AbstractAmong the settlers that, from 1432 onwards, arrived to the Azores Islands were individuals of North and sub‐Saharan African origin. A previous study of markers of the Y chromosome revealed that haplogroup E is the second more frequent in the Azores (13%). Since this haplogroup is heterogeneous and may contain subtypes of African or non‐African origin, we analyzed an extended sample of 319 Azoreans, originating from the three groups of islands (Eastern, Central, and Western), to evaluate the African contribution to the present‐day population of the Azores. Samples belonging to the E clade were distributed into six haplogroups, from which the most frequent was E3b1a, representing 47.2% of the E chromosomes (6.3% of the total sample). The sub‐Saharan haplogroup E3a was found in 7.1% of E chromosomes (0.9% of the total), corresponding to the highest frequency reported so far in a Portuguese population. No significant differences were detected in the haplogroup distribution among groups of islands, as well as between Azores and most of other European populations compared. The present‐day representation of sub‐Saharan lineages in Azores, although reduced, is higher than in other Portuguese populations, where the demographic representation of sub‐Saharan slaves is reported as similar. Am. J. Hum. Biol., 2007. © 2007 Wiley‐Liss, Inc.