bluuebunny/crossref_metadata_2025_split huggingface dataset:
Myeloma bone disease and proteasome inhibition therapies
Authors: Terpos Evangelos , Sezer Orhan , Croucher Peter , Dimopoulos Meletios-Athanassios 
Published: May 2007

AbstractBone disease is one of the most debilitating manifestations of multiple myeloma. A complex interdependence exists between myeloma bone disease and tumor growth, creating a vicious circle of extensive bone destruction and myeloma progression. Proteasome inhibitors have recently been shown to promote bone formation in vitro and in vivo. Preclinical studies have demonstrated that proteasome inhibitors, including bortezomib, which is the first-in-class such agent, stimulate osteoblast differentiation while inhibiting osteoclast formation and bone resorption. Clinical studies are confirming these observations. Bortezomib counteracts the abnormal balance of osteoclast regulators (receptor activator of nuclear factor-κB ligand and osteoprotegerin), leading to osteoclast inhibition and decreased bone destruction, as measured by a reduction in markers of bone resorption. In addition, bortezomib stimulates osteoblast function, possibly through the reduction of dickkopf-1, leading to increased bone formation, as indicated by the elevation in bone-specific alkaline phosphatase and osteocalcin. The effect of bortezomib on bone disease is thought to be direct and not only a consequence of the agent's antimyeloma properties, making it an attractive agent for further investigation, as it may combine potent antimyeloma activity with beneficial effects on bone. However, the clinical implication of these effects requires prospective studies with specific clinical end points.
MN1 overexpression induces acute myeloid leukemia in mice and predicts ATRA resistance in patients with AML
Authors: Heuser Michael , Argiropoulos Bob , Kuchenbauer Florian , Yung Eric , Piper Jessica , Fung Stephen , Schlenk Richard F. , Dohner Konstanze , Hinrichsen Tanja , Rudolph Cornelia , Schambach Axel , Baum Christopher , Schlegelberger Brigitte , Dohner Hartmut , Ganser Arnold , Humphries R. Keith 
Published: May 2007

AbstractOverexpression of wild-type MN1 is a negative prognostic factor in patients with acute myeloid leukemia (AML) with normal cytogenetics. We evaluated whether MN1 plays a functional role in leukemogenesis. We demonstrate using retroviral gene transfer and bone marrow (BM) transplantation that MN1 overexpression rapidly induces lethal AML in mice. Insertional mutagenesis and chromosomal instability were ruled out as secondary aberrations. MN1 increased resistance to all-trans retinoic acid (ATRA)–induced cell-cycle arrest and differentiation by more than 3000-fold in vitro. The differentiation block could be released by fusion of a transcriptional activator (VP16) to MN1 without affecting the ability to immortalize BM cells, suggesting that MN1 blocks differentiation by transcriptional repression. We then evaluated whether MN1 expression levels in patients with AML (excluding M3-AML) correlated with resistance to ATRA treatment in elderly patients uniformly treated within treatment protocol AMLHD98-B. Strikingly, patients with low MN1 expression who received ATRA had a significantly prolonged event-free (P = .008) and overall (P = .04) survival compared with patients with either low MN1 expression and no ATRA, or high MN1 expression with or without ATRA. MN1 is a unique oncogene in hematopoiesis that both promotes proliferation/self-renewal and blocks differentiation, and may become useful as a predictive marker in AML treatment.
Stringent and reproducible tetracycline-regulated transgene expression by site-specific insertion at chromosomal loci with pre-characterised induction characteristics
Authors: Brough Rachel , Papanastasiou Antigoni M , Porter Andrew CG 
Published: May 2007

Abstract

Background
The ability to regulate transgene expression has many applications, mostly concerning the analysis of gene function. Desirable induction characteristics, such as low un-induced expression, high induced expression and limited cellular heterogeneity, can be seriously impaired by chromosomal position effects at the site of transgene integration. Many clones may therefore need to be screened before one with optimal induction characteristics is identified. Furthermore, such screens must be repeated for each new transgene investigated, and comparisons between clones with different transgenes is complicated by their different integration sites.

Results
To circumvent these problems we have developed a "screen and insert" strategy in which clones carrying a transgene for a fluorescent reporter are first screened for those with optimal induction characteristics. Site-specific recombination (SSR) is then be used repeatedly to insert any new transgene at the reporter transgene locus of such clones so that optimal induction characteristics are conferred upon it. Here we have tested in a human fibrosarcoma cell line (HT1080) two of many possible implementations of this approach. Clones (e.g. Rht14-10) in which a GFP reporter gene is very stringently regulated by the tetracycline (tet) transactivator (tTA) protein were first identified flow-cytometrically. Transgenes encoding luciferase, I-Sce I endonuclease or Rad52 were then inserted by SSR at a LoxP site adjacent to the GFP gene resulting stringent tet-regulated transgene expression. In clone Rht14-10, increases in expression from essentially background levels (+tet) to more than 104-fold above background (-tet) were reproducibly detected after Cre-mediated insertion of either the luciferase or the I-Sce I transgenes.

Conclusion
Although previous methods have made use of SSR to integrate transgenes at defined sites, none has effectively combined this with a pre-selection step to identify integration sites that support optimal regulatory characteristics. Rht14-10 and similar HT1080-derived clones can now be used in conjunction with a convenient delivery vector (pIN2-neoMCS), in a simple 3-step protocol leading to stringent and reproducible transgene regulation. This approach will be particularly useful for transgenes whose products are very active at low concentrations and/or for comparisons of multiple related transgenes.
Development of expression vectors for Escherichia coli based on the pCR2 replicon
Authors: Walia Rupali , Deb J K , Mukherjee K J 
Published: May 2007

Abstract

Background
Recent developments in metabolic engineering and the need for expanded compatibility required for co-expression studies, underscore the importance of developing new plasmid vectors with properties such as stability and compatibility.

Results
We utilized the pCR2 replicon of Corynebacterium renale, which harbours multiple plasmids, for constructing a range of expression vectors. Different antibiotic-resistance markers were introduced and the vectors were found to be 100% stable over a large number of generations in the absence of selection pressure. Compatibility of this plasmid was studied with different Escherichia coli plasmid replicons viz. pMB1 and p15A. It was observed that pCR2 was able to coexist with these E.coli plasmids for 60 generations in the absence of selection pressure. Soluble intracellular production was checked by expressing GFP under the lac promoter in an expression plasmid pCR2GFP. Also high level production of human IFNγ was obtained by cloning the h-IFNγ under a T7 promoter in the expression plasmid pCR2-IFNγ and using a dual plasmid heat shock system for expression. Repeated sub-culturing in the absence of selection pressure for six days did not lead to any fall in the production levels post induction, for both GFP and h-IFNγ, demonstrating that pCR2 is a useful plasmid in terms of stability and compatibility.

Conclusion
We have constructed a series of expression vectors based on the pCR2 replicon and demonstrated its high stability and sustained expression capacity, in the absence of selection pressure which will make it an efficient tool for metabolic engineering and co-expression studies, as well as for scale up of expression.
Dissociation Kinetics and Complexation Equilibrium Studies of a ZnII Complex with 1,5-Bis(2-hydroxy-5-sulfophenyl)-3-cyanoformazan during Capillary Electrophoretic Separation Process
Authors: Takahashi Toru , Takehara Yuka , Hoshino Hitoshi 
Published: May 2007

Abstract
The dissociation kinetics and the complexation equilibrium of a ZnII complex with 1,5-bis(2-hydroxy-5-sulfophenyl)-3-cyanoformazan (hscf: H5L) during capillary electrophoretic (CE) separation process were studied. The solvolytic dissociation reaction rate constants of the ZnII–hscf complex ([ZnL]3−) (kd) in the pH range of 6.4 to 8.0 were determined with a CE-based dissociation kinetic analysis method. Small kd values on the order of 10−5 s−1 showed the remarkable kinetic inertness of [ZnL]3−, which was detectable in the CE system. The stability constant of [ZnL]3− (KZnL) at 293 K and I = 0.10 was estimated to be [ZnL3−]/{[Zn2+][L5−]} = 1024.2±0.3 through the spectrophotometric titration. The thermodynamic stability of [ZnL]3− in the pre-capillary complexation stage was thus demonstrated. In contrast, it was shown that the CE separation environment is thermodynamically unsuitable for the metal complexes based on the conditional stability constant of [ZnL]3−, which was determined under CE separation conditions, and the concentration of free HSCF in the complex band in the capillary. Thus, the “stability” of metal complex in the CE system strongly depends on kinetic inertness rather than thermodynamic stability, though their thermodynamic stability is necessary for the pre-capillary derivatization step.
Synthesis, Structures, and Properties of Nickel(II) Mixed-Ligand Complexes Containing Various β-Diketonates and a Phosphorus Donor Bidentate Ligand
Authors: Arakawa Machiko , Miyamae Hiroshi , Fukuda Yutaka 
Published: May 2007

Abstract
New mixed-ligand nickel(II) complexes containing β-diketonates and 1,2-bis(diphenylphosphino)ethane, [Ni(dike)(dppe)]X (X = BF4, ClO4, and NO3) were synthesized and characterized. Since the ligand field strength of the phosphorus donor is very strong, the complexes [Ni(dike)(dppe)]X studied in this work are as stable as the square-planar both in solid state and in solutions.
Comparison of Brain Natriuretic Peptide (BNP) and Amino-Terminal ProBNP for Early Diagnosis of Heart Failure
Authors: Emdin Michele , Passino Claudio , Prontera Concetta , Fontana Marianna , Poletti Roberta , Gabutti Alessandra , Mammini Chiara , Giannoni Alberto , Zyw Luc , Zucchelli Giancarlo , Clerico Aldo 
Published: May 2007

Abstract
Background: We compared the diagnostic accuracy of brain natriuretic peptide (BNP) and amino-terminal proBNP (NT-proBNP) for diagnosis of preclinical and mild heart failure (HF).
Methods: We assayed plasma NT-proBNP and BNP in 182 healthy controls and in a prospective cohort of 820 HF patients divided according to the American Heart Association/American College of Cardiology classification. These included 86 patients in stage A [mean (SE) ejection fraction 61% (1%); mean (SE) age 47 (2) years], 255 in stage B [65% (2%); 62 (1) years], 420 patients in stage C [35% (1%); 68 (1) years] and 59 in stage D [25% (1%); 74 (1) years]. Diagnostic accuracies of BNP and NT-proBNP were evaluated by ROC analysis, and a multivariate linear regression model was applied to predict HF staging.
Results: Median BNP and NT-proBNP concentrations increased from stage A to D 57-fold and 107-fold, respectively. Both assays were accurate (P &lt;0.001) in separating stage B from controls or stage A, and stage C from controls or stage A or B. NT-proBNP was more accurate (P &lt;0.001) than BNP in differentiating stage C from stages A and B patients and controls and was a better predictor of HF classification in a model including age, sex, and renal function (P &lt;0.001).
Conclusions: Monitoring BNP or NT-proBNP enabled identification of asymptomatic patients at risk for the development of HF. NT-proBNP showed better accuracy than BNP for identifying mild HF.
Increased Plasma Concentrations of Soluble CD40 Ligand in Acute Coronary Syndrome Depend on in Vitro Platelet Activation
Authors: Ivandic Boris T , Spanuth Eberhard , Haase Detlef , Lestin Heiko-Gundmar , Katus Hugo A 
Published: May 2007

Abstract
Background: Soluble CD40 ligand (sCD40L) was suggested as a novel biomarker of cardiovascular risk. We examined the effect of preanalytical variation on the measurement of sCD40L concentration.
Methods: From healthy control individuals (n = 20) and patients with acute coronary syndrome (ACS) (n = 20) or sepsis (n = 20), we obtained blood drawn into 5 tubes containing citrate or a mixture of citrate, theophylline, adenosine, and dipyridamole (CTAD). The tubes were incubated for 30 min at room temperature or 0 °C before a single or double centrifugation (15 min, 2500g) at room temperature or 4 °C, respectively. sCD40L, β-thromboglobulin (βTG), and platelet factor 4 (PF4) concentrations were measured using immunoassays.
Results: Concentrations of sCD40L were very low in all CTAD and citrated samples maintained at 0 °C (median ≤0.076 μg/L). Although increased βTG and PF4 confirmed disease-related in vivo platelet activation, sCD40L was not higher in patients than in controls. In contrast, if the samples were processed at room temperature, sCD40L was significantly higher in ACS patients than in controls (P &lt;0.02 in CTAD and citrated plasma at room temperature). Moreover, the βTG:PF4 ratio decreased in patient but not control CTAD samples, suggesting a greater susceptibility of patient platelets to in vitro activation.
Conclusions: Increased sCD40L concentrations resulted from in vitro platelet activation during sample preparation. Disease-related in vivo activation did not contribute to sCD40L concentrations in plasma. Therefore, published studies of sCD40L demand cautious interpretation, because their preanalytical conditions were not standardized.
Large‐Scale Synthesis, Annealing, Purification, and Magnetic Properties of Crystalline Helical Carbon Nanotubes with Symmetrical Structures
Authors: Tang N. J. , Zhong W. , Au C. T. , Gedanken A. , Yang Y. , Du Y. W. 
Published: May 2007

AbstractCrystalline helical carbon nanotubes (HCNTs) are synthesized as the main products in the pyrolysis of acetylene at 450 °C over Fe nanoparticles generated by means of a combined sol–gel/reduction method. Transmission electron microscopy (TEM) images reveal that there are two HCNTs attached to each Fe3C nanoparticle, and that the two HCNTs are mirror images of each other. Annealing in Ar at 750 °C and purification by immersion in hot (90 °C) HCl solution do not significantly change the structure of the HCNTs, despite the partial removal of Fe nanoparticles by the latter treatment. The magnetic properties of the as‐prepared, annealed, and purified HCNTs have been systematically examined. The annealed sample shows relatively high magnetization due to the ferromagnetic α‐Fe nanoparticles encapsulated in the HCNT nodes. In the case of HCl treatment, relatively pure HCNTs are obtained by the removal of ferromagnetic nanoparticles from the double‐HCNT nodes. The effects of the amount of catalyst used in the synthesis process on the morphology and yield of the carbon products have also been investigated.
Blood eosinophils in workers with aluminum potroom asthma are increased to higher levels in non‐smokers than in smokers
Authors: Sjåheim Tone , Kongerud Johny , Søyseth Vidar 
Published: May 2007

AbstractBackgroundAluminum potroom asthma (PA) has been described in several reports. This study aimed to investigate the association between blood eosinophils and PA.MethodsIn a cross‐sectional study, 338 workers were examined as follows: spirometry, blood eosinophils, skin prick test, and work exposure measurements. They also completed a questionnaire on respiratory symptoms, smoking, allergy, and duration of work exposure.ResultsThe odds ratio for PA was 4.2 (95% confidence interval 1.5–9.7) for workers with eosinophils ≥400 × 106 cells/L compared with workers with eosinophils <200 × 106 cells/L. In non‐smokers, the number of eosinophils was 177 × 106 cells/L (P < 0.001) higher among workers with PA than asymptomatic workers, whereas the corresponding difference among current smokers was only 63 × 106 cells/L (P = 0.03).ConclusionsThe prevalence of PA was positively associated with blood eosinophils. An attenuation of the blood eosinophil increase was observed in smoking asthmatics, suggesting an immune‐modulating effect of smoking. Am. J. Ind. Med. 50:443–448, 2007. © 2007 Wiley‐Liss, Inc.
Evidence for association and epistasis at the DAOA/G30 and D‐amino acid oxidase loci in an Irish schizophrenia sample
Authors: Corvin A. , McGhee K.A. , Murphy K. , Donohoe G. , Nangle J.M. , Schwaiger S. , Kenny N. , Clarke S. , Meagher D. , Quinn J. , Scully P. , Baldwin P. , Browne D. , Walsh C. , Waddington J.L. , Morris D.W. , Gill M. 
Published: May 2007

AbstractThe D‐amino acid oxidase (DAO) signaling pathway has been implicated in schizophrenia pathogenesis. This may be mediated through modulation of NMDA function by DAO, which is in turn activated by DAO activator (DAOA, formerly G72). Chumakov et al. (2002); PNAS 99: 13675–13680, identifying the novel schizophrenia susceptibility gene DAOA/G30 and a number of independent studies have since reported evidence of association between the DAOA and DAO genes and schizophrenia. However, at least two studies have failed to replicate the epistatic interaction between these loci described in the original report and there have been differences in the associated alleles/haplotypes reported at each locus. In this study, we performed association and epistasis analyses of the DAOA/G30 and DAO loci in a sample of 373 cases with DSM‐IV schizophrenia/schizoaffective disorder and 812 controls from the Republic of Ireland. Corrected for the number of tests performed, we found evidence for association between markers at both genes and schizophrenia: DAOA/G30 (P = 0.005, OR = 1.34 (1.09, 1.65)) and DAO (P = 0.003, OR = 1.43 (1.12, 1.84). The data suggest that evidence for association at DAO (marker rs2111902) is more consistent than previously realized, particularly in Caucasian schizophrenia populations. We identified evidence for epistatic interaction between the associated SNPs at DAOA and DAO genes in contributing to schizophrenia risk (OR = 9.3 (1.4, 60.5). Based on these data, more systematic investigation of genes involved in DAO signaling is required. © 2007 Wiley‐Liss, Inc.
CO2 Fixation and Transformation by a Dinuclear Copper Cryptate under Acidic Conditions
Authors: Chen Jia‐Mei , Wei Wei , Feng Xiao‐Long , Lu Tong‐Bu 
Published: May 2007

AbstractCO2 fixation and transformation by metal complexes continuously receive attention from the viewpoint of carbon resources and environmental concerns. We found that the dinuclear copper(II) cryptate [Cu2L1](ClO4)4 (1; L1=N[(CH2)2NHCH2(m‐C6H4)CH2NH‐(CH2)2]3N) can easily take up atmospheric CO2 even under weakly acidic conditions at room temperature and convert it from bicarbonate into carbonate monoesters in alcohol solution. The compounds [Cu2L1(μ‐O2COH)](ClO4)3 (2), [Cu2L1(μ‐O2COR)](ClO4)3 (3: R=CH3; 4: R=C2H5; 5: R=C3H7; 6: R=C4H9; 7: R=C5H11; 8: R=CH2CH2OH), [Cu2L1(μ‐O2CCH3)](ClO4)3 (9), and [Cu2L1(OH2)(NO3)](NO3)3 (10) were characterized by IR spectroscopy and ESI‐MS. The crystal structures of 2–6 and 10 were studied by single‐crystal X‐ray diffraction analysis. On the basis of the crystal structures, solution studies, and DFT calculations, a possible mechanism for CO2 fixation and transformation is given.
Effects of mobile phone electromagnetic fields on an auditory order threshold task
Authors: Cinel Caterina , Boldini Angela , Russo Riccardo , Fox Elaine 
Published: May 2007

AbstractThe effect of acute exposure to radio frequency electromagnetic fields (RF EMF) generated by mobile phones on an auditory threshold task was investigated. 168 participants performed the task while exposed to RF EMF in one testing session (either global system for mobile communication (GSM) or unmodulated signals) while in a separate session participants were exposed to sham signals. Lateralization effects were tested by exposing participants either on the left side or on the right side of the head. No significant effect of exposure to RF EMF was detected, suggesting that acute exposure to RF EMFs does not affect performance in the order threshold task. Bioelectromagnetics 28:493–496, 2007. © 2007 Wiley‐Liss, Inc.
Exposure of pregnant dairy heifer to magnetic fields at 60 Hz and 30 µT
Authors: Burchard J.F. , Nguyen D.H. , Monardes H.G. 
Published: May 2007

AbstractThirty‐two pregnant Holstein heifers weighing 499 ± 45 kg, at 3.1 ± .7 months of gestation and 21 ± 2.0 months of age were confined and exposed to 30 µT magnetic fields (MFs) and a 12 h light/12 h dark light cycle. The heifers were divided into two replicates of 16 animals. Each replicate was divided into two groups of eight animals each, one group the non‐exposed and the second, the exposed group. The animals were subjected to the different treatments for 4 weeks. After 4 weeks, the animals switched treatment, the exposed group becoming the non‐exposed group and vice versa. Then the treatment continued for 4 more weeks. Catheters were inserted into the jugular vein, and blood samples were collected twice a week to estimate the concentration of progesterone (P4), melatonin (MLT), prolactin (PRL), and insulin‐like growth factor 1 (IGF‐1). Feed consumption was measured daily. The results indicated that exposure of pregnant heifers to MF similar to those encountered underneath a 735 kV high tension electrical power line for 20 h/day during a period of 4 weeks produces slight effects. This is evidenced by statistically significant higher body weight (1.2%), higher weekly body weight gain (30%), and decreases in the concentration of PRL (15%) and IGF‐1 (4%) in blood serum. The absence of abnormal clinical signs and the absolute magnitude of the significant changes detected during MF exposure, make it plausible to preclude any major animal health hazard. Bioelectromagnetics 28:471–476, 2007. © 2007 Wiley‐Liss, Inc.
Combination of biotransformation and chromatography for the isolation and purification of mannoheptulose
Authors: Kappler‐Tanudyaya Nathalie , Schmitt Heike , Tippkötter Nils , Meyer Lina , Lenzen Sigurd , Ulber Roland 
Published: May 2007

AbstractMannoheptulose is a seven‐carbon sugar. It is an inhibitor of glucose‐induced insulin secretion due to its ability to selectively inhibit the enzyme glucokinase. An improved procedure for mannoheptulose isolation from avocados is described in this study (based upon the original method by La Forge). The study focuses on the combination of biotransformation and downstream processing (preparative chromatography) as an efficient method to produce a pure extract of mannoheptulose. The experiments were divided into two major phases. In the first phase, several methods and parameters were compared to optimize the mannoheptulose extraction with respect to efficiency and purity. In the second phase, a mass balance of mannoheptulose over the whole extraction process was undertaken to estimate the yield and efficiency of the total extraction process. The combination of biotransformation and preparative chromatography allowed the production of a pure mannoheptulose extract. In a biological test, the sugar inhibited the glucokinase enzyme activity efficiently.