bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cyclin D1 as a Target for the Proliferative Effects of PTH and PTHrP in Early Osteoblastic Cells
Authors: Datta Nabanita S , Pettway Glenda J , Chen Chen , Koh Amy J , McCauley Laurie K 
Published: March 2007

Abstract
PTHrP induced a proliferative cyclin D1 activation in low-density osteoblastic cells. The process was PKA and MAPK dependent and involved both AP-1 and CRE sites. In ectopic ossicles generated from implanted bone marrow stromal cells, PTH upregulated cyclin D1 after acute or intermittent anabolic treatment. These data suggest a positive role of PTH and PTHrP in the cell cycle of early osteoblasts.
Introduction: The mechanisms underlying the actions of PTH and its related protein (PTHrP) in osteoblast proliferation, differentiation, and bone remodeling remain unclear. The action of PTH or PTHrP on the cell cycle during osteoblast proliferation was studied.
Materials and Methods: Mouse calvarial MC3T3-E1 clone 4 cells were synchronized by serum starvation and induced with 100 nM PTHrP for 2–24 h under defined low serum conditions. Western blot, real-time PCR, EMSAs, and promoter/luciferase assays were performed to evaluate cyclin D1 expression. Pharmacological inhibitors were used to determine the relevant signaling pathways. Ectopic ossicles generated from implanted bone marrow stromal cells were treated with acute (a single 8- or 12-h injection) or intermittent anabolic PTH treatment for 7 days, and RNA and histologic analysis were performed.
Results: PTHrP upregulated cyclin D1 and CDK1 and decreased p27 expression. Cyclin D1 promoter/luciferase assays showed that the PTHrP regulation involved both activator protein-1 (AP-1) and cyclic AMP response element binding protein (CRE) sites. AP-1 and CRE double mutants completely abolished the PTHrP effect of cyclin D1 transcription. Upregulation of cyclin D1 was found to be protein kinase A (PKA) and mitogen-activated protein kinase (MAPK) dependent in proliferating MC3T3-E1 cells. In vivo expression of cyclin D1 in ectopic ossicles was upregulated after a single 12-h PTH injection or intermittent anabolic PTH treatment for 7 days in early developing ossicles.
Conclusions: These data indicate that PTH and PTHrP induce cyclin D1 expression in early osteoblastic cells and their action is developmental stage specific.
ApoE Gene Deficiency Enhances the Reduction of Bone Formation Induced by a High-Fat Diet Through the Stimulation of p53-Mediated Apoptosis in Osteoblastic Cells
Authors: Hirasawa Hideyuki , Tanaka Shinya , Sakai Akinori , Tsutsui Masato , Shimokawa Hiroaki , Miyata Hironori , Moriwaki Sawako , Niida Shumpei , Ito Masako , Nakamura Toshitaka 
Published: March 2007

AbstractOsteoblast apoptosis increased in the tibias of apoE−/− mice fed with a high-fat diet, decreasing bone formation. The expression of p53 mRNA in marrow adherent cells increased. LDL or oxidized LDL increased apoptosis in the calvarial cells of apoE−/− mice. The increase in p53-mediated apoptosis is apparently related to a high-fat diet–induced osteopenia in apoE−/− mice.Introduction: The effects of high-fat loading and the apolipoprotein E (apoE) gene on bones have not been elucidated. We hypothesized that apoE gene deficiency (apoE−/−) modulates the effects of high-fat loading on bones.Materials and Methods: We assessed this hypothesis using wildtype (WT) and apoE−/− mice fed a standard (WTS and ApoES groups) or a high-fat diet (WTHf and ApoEHf groups). The concentration of serum lipid levels and bone chemical markers were measured. Histomorphometry of the femurs was performed using μCT and a microscope. Bone marrow adherent cells from the femurs were used for colony-forming unit (CFU)-fibroblastic (CFU-f) assay and mRNA expressions analysis. The apoptotic cells in the tibias were counted. TUNEL fluorescein assay and Western analysis were performed in cultures of calvarial cells by the addition of low-density lipoprotein (LDL) or oxidized LDL.Results: In the ApoEHf group, the values of cortical bone volume and trabecular and endocortical bone formation of the femurs decreased, and urinary deoxypyridinoline increased. Subsequent analysis revealed that the number of apoptotic cells in the tibias of the ApoES group increased, and more so in the ApoEHf group. The ratio of alkaline phosphatase–positive CFU-f to total CFU-f was decreased in the ApoEHf group. p53 mRNA expression in adherent cells of the apoE−/− mice increased and had a significantly strong positive correlation with serum LDL. TUNEL fluorescein assay of osteoblastic cells revealed an increase of apoptotic cells in the apoE−/− mice. The number of apoptotic cells in the apoE−/− mice increased with the addition of 100 μg/ml LDL or oxidized LDL. The p53 protein expression in apoE−/− cells exposed to 100 μg/ml LDL or oxidized LDL increased.Conclusions: We concluded that apoE gene deficiency enhances the reduction of bone formation induced by a high-fat diet through the stimulation of p53-mediated apoptosis in osteoblastic cells.
Variability in the Relationship between Mean Plasma Glucose and HbA1c: Implications for the Assessment of Glycemic Control
Authors: Kilpatrick Eric S , Rigby Alan S , Atkin Stephen L 
Published: March 2007

AbstractBackground: Previous studies have shown a single linear relationship between mean plasma glucose (MPG) and hemoglobin A1c (HbA1c). We examined the relationship in different treatment groups of patients with type 1 diabetes participating in the Diabetes Control and Complications Trial (DCCT).Methods: Seven-point glucose profiles (premeal, postmeal, and bedtime) and HbA1c were measured quarterly during the DCCT. We studied measurements from (a) intensively treated patients at study commencement, (b) intensively treated patients after stabilization of their glycemia (from 6 months onward), and (c) conventionally treated patients from 6 months onward. Only complete glucose profile and HbA1c pairings were considered (n = 589, 11 483, and 11 855, respectively).Results: From 6 months into the trial, conventionally treated patients had consistently higher MPG concentrations than intensively treated patients at any given HbA1c value (mean difference, 1.6 mmol/L at 7% HbA1c, increasing to 2.8 mmol/L at 11% HbA1c). Similarly, at the same HbA1c, the MPG of intensively treated patients at baseline was higher than in the same individuals after 6 months of intensive treatment (1.2 mmol/L difference at 7% HbA1c, increasing to 4.6 mmol/L at 11% HbA1c).Conclusions: The relationship between MPG and HbA1c is not constant but differs depending on the glycemic control of the population being studied. Having lower mean glucose at the same HbA1c may help explain why intensive DCCT treatment appeared intrinsically linked to both increased hypoglycemia and decreased microvascular complications compared with conventional treatment. These findings may also have implications for expressing HbA1c as mean blood glucose equivalent.
Chronic Granulomatous Disease (CGD) and Complete Myeloperoxidase Deficiency Both Yield Strongly Reduced Dihydrorhodamine 123 Test Signals but Can Be Easily Discerned in Routine Testing for CGD
Authors: Mauch Lysann , Lun Andreas , O’Gorman Maurice RG , Harris John S , Schulze Ilka , Zychlinsky Arturo , Fuchs Tobias , Oelschlägel Uta , Brenner Sebastian , Kutter Dolphe , Rösen-Wolff Angela , Roesler Joachim 
Published: March 2007

AbstractBackground: The flow cytometric dihydrorhodamine 123 (DHR) assay is used as a screening test for chronic granulomatous disease (CGD), but complete myeloperoxidase (MPO) deficiency can also lead to a strongly decreased DHR signal. Our aim was to devise simple laboratory methods to differentiate MPO deficiency (false positive for CGD) and NADPH oxidase abnormalities (true CGD).Methods: We measured NADPH-oxidase and MPO activity in neutrophils from MPO-deficient patients, CGD patients, NADPH-oxidase–transfected K562 cells and cells with inhibited and substituted MPO.Results: Eosinophils from MPO-deficient individuals retain eosinophilic peroxidase and therefore generate a normal DHR signal. The addition of recombinant human MPO enhances the DHR signal when simply added to a suspension of MPO-deficient cells but not when added to NADPH-oxidase–deficient (CGD) cells. Lucigenin-enhanced chemiluminescence (LCL) is increased in neutrophils from MPO-deficient patients, whereas neutrophils from patients with CGD show a decreased response.Conclusions: A false-positive result caused by MPO deficiency can be easily ascertained because, unlike cells from a CGD patient, cells from MPO-deficient patients (a) contain functionally normal eosinophils, (b) show a significant enhancement of the DHR signal following addition of rhMPO, and (c) generate a strong LCL signal.
SPP1 Promoter Polymorphisms: Identification of the First Modifier Gene for Pseudoxanthoma Elasticum
Authors: Hendig Doris , Arndt Marius , Szliska Christiane , Kleesiek Knut , Götting Christian 
Published: March 2007

Abstract
Background: Progressive calcification and fragmentation of elastic fibers are characteristic hallmarks of pseudoxanthoma elasticum (PXE), which is caused by mutations in ABCC6 encoding multidrug resistance–associated protein 6 (MRP6). Because of the great clinical variability of PXE, secondary genetic risk factors are suspected to exist. We investigated whether SPP1 (secreted phosphoprotein 1; previously OPN, osteopontin) promoter polymorphisms are associated with PXE.
Methods: We screened an ∼2-kb region spanning the theoretical promoter of the SPP1 gene for sequence variations by denaturing HPLC and direct sequencing in 93 PXE patients. Sequence variations with a prevalence &gt;5% were genotyped in 93 age- and sex-matched healthy controls. Statistical and haplotype association analyses were performed using Fisher exact test, PHASE v2.1.1, and Haploview 3.2.
Results: Mutational screening revealed 9 different sequence variations. Three SPP1 promoter polymorphisms (c.−1748A&gt;G, c.−155_156insG, and c.244_245insTG) were significantly more frequent in PXE patients than in 93 age- and sex-matched healthy controls (Pcorrected &lt; 0.05 each). The odds ratios (95% CI) for PXE among carriers of the 3 alleles were, respectively, 2.16 (1.34–3.48), 2.41 (1.51–3.82), and 1.97 (1.23–3.15). Haplotype analysis of 6 SPP1 promoter polymorphisms revealed 1 haplotype to be significantly reduced among PXE patients (Pcorrected = 0.035, odds ratio 1.80, 95% CI 1.19–2.71).
Conclusions: Polymorphisms in the SPP1 promoter are secondary genetic risk factors contributing to PXE susceptibility.
Folate and Methylation Status in Relation to Phosphorylated Tau Protein(181P) and β-Amyloid(1–42) in Cerebrospinal Fluid
Authors: Obeid Rima , Kasoha Mariz , Knapp Jean-Pierre , Kostopoulos Panagiotis , Becker George , Fassbender Klaus , Herrmann Wolfgang 
Published: March 2007

AbstractBackground: Increased plasma total homocysteine (tHcy) is a risk factor for neurological diseases, but the underlying pathophysiology has not been adequately explained.Methods: We evaluated concentrations of tHcy, S-adenosyl homocysteine (SAH), S-adenosyl methionine (SAM), folate, and vitamin B12 in cerebrospinal fluid (CSF) and plasma or serum from 182 patients with different neurological disorders. We measured concentrations of phosphorylated tau protein (P-tau)(181P) and β-amyloid(1–42) in the CSF.Results: Aging was associated with higher concentrations of tHcy and SAH in the CSF, in addition to lower concentrations of CSF folate and lower SAM:SAH ratio. Concentrations of CSF SAH and CSF folate correlated significantly with those of P-tau (r = 0.46 and r = −0.28, respectively). Moreover, P-tau correlated negatively with SAM:SAH ratio (r = −0.40, P &lt;0.001). The association between SAH and higher P-tau was observed in 3 age groups (&lt;41, 41–60, and &gt;60 years). CSF tHcy was predicted by concentrations of CSF cystathionine (β = 0.478), folate (β = −0.403), albumin (β = 0.349), and age (β = 0.298).Conclusions: tHcy concentration in the brain is related to age, B vitamins, and CSF albumin. Increase of CSF SAH is related to increased CSF P-tau; decreased degradation of P-tau might be a plausible explanation. Disturbed methyl group metabolism may be the link between hyperhomocysteinemia and neurodegeneration. Lowering tHcy and SAH might protect the brain by preventing P-tau accumulation.
Are Auditors Compromised by Nonaudit Services? Assessing the Evidence*
Authors: Francis Jere R. 
Published: March 2007

AbstractRuddock, Taylor, and Taylor (2006) use an earnings conservatism framework to investigate the effects of nonaudit services (NAS) on earnings conservatism, and to test whether audit quality was impaired by NAS in Australia during the 1990s. They find no evidence of differential conservatism conditional on the level of NAS fees paid to auditors, and thus conclude that NAS have no adverse effect on audit quality. While this result may not extrapolate to the U.S. setting due to institutional difference between the two countries, the study does add to a growing body of empirical evidence that questions whether there is any logical rationale for restricting the scope of the services that auditors provide to their audit clients. In reviewing the NAS research literature over the past 40 years, one has to conclude that there is no “smoking gun” evidence linking the provision of nonaudit services with audit failures. However, the literature also finds that NAS can adversely affect the appearance of auditor independence, and this may be more than a “mere perception” problem, because there is also evidence that stock prices are significantly lower for companies that pay their auditors large fees for nonaudit services.
Ownership Structure, Business Group Affiliation, Listing Status, and Earnings Management: Evidence from Korea*
Authors: Kim Jeong‐Bon , Yi Cheong H. 
Published: March 2007

AbstractUsing a large sample of both publicly traded and privately held firms in South Korea (hereafter “Korea”), we investigate whether, and how, the deviation of controlling shareholders' control from ownership, business group affiliation, and listing status differentially affect the extent of earnings management. Our study yields three major findings. First, we find that as the control‐ownership disparity becomes larger, controlling shareholders tend to engage more in opportunistic earnings management to hide their behavior and avoid adverse consequences such as disciplinary action. The result of our full‐model regression reveals that an increase in the control‐ownership wedge by 1 percent leads to an increase in the magnitude of (unsigned) discretionary accruals by 1.3 percent of lagged total assets, ceteris paribus. Second, we find that for our full‐model regression, the magnitude of (unsigned) discretionary accruals is greater for group‐affiliated firms than for nonaffiliated firms by 0.8 percent of lagged total assets. This result suggests that business group affiliation provides controlling shareholders with more incentives and opportunities for earnings management. Finally, we find that for our full‐model regression, the magnitude of (unsigned) discretionary accruals is greater for publicly traded firms than for privately held firms by 1.2 percent of lagged total assets. This result supports the notion that stock markets create incentives for public firms to manage reported earnings to satisfy the expectations of various market participants that are often expressed in earnings numbers.
Who Benefits from Inconsistent Multinational Tax Transfer‐Pricing Rules?*
Authors: De Waegenaere Anja , Sansing Richard C. , Wielhouwer Jacco L. 
Published: March 2007

AbstractThis paper uses a strategic tax compliance model to examine taxpayer reporting and tax authority audit strategies in an international setting with two tax authorities. The setting features both information asymmetry between the taxpayer and the tax authorities and inconsistent tax transfer‐pricing rules. The latter creates the possibility of each country trying to tax the same income. We study the effect of the probability of transfer‐price rule inconsistency on the strategies and payoffs of the taxpayer and the tax authorities. We find that an increase in the probability of transfer‐price rule inconsistency induces more aggressive auditing by governments. It therefore deters taxpayers from shifting income to the country with the lower tax rate in situations in which the transfer‐pricing rules are consistent, and can either increase or decrease the income reported to the low‐tax‐rate country in cases in which the transfer‐pricing rules are inconsistent. We find that an increase in transfer‐price rule inconsistency could either increase or decrease the taxpayer's expected tax liability and could either increase or decrease the deadweight loss from auditing. Our results call into question the conventional wisdom that the prospect of double taxation due to transfer‐price rule inconsistency increases a firm's expected tax liability and governments' expected audit costs.
Did Houston Clients of Arthur Andersen Recognize Publicly Available Bad News in a Timely Fashion?*
Authors: KRISHNAN GOPAL V. 
Published: March 2007

AbstractDespite the allegations of audit failure and the enormous publicity surrounding Arthur Andersen's indictment, there is no systematic empirical evidence on characteristics of accounting information of clients of Arthur Andersen vis‐à‐vis other Big 6 auditors. I examine whether earnings of Andersen's Houston‐based clients are timely in reporting bad news about future cash flows. I find that relative to a control group consisting of Houston‐based clients audited by other Big 6 auditors, earnings of Andersen clients are less timely in reporting bad news. Further, it appears that operating accruals of Andersen clients are less effective in accelerating the timely recognition of bad news than operating accruals of non‐Andersen clients. The findings suggest that the clients of Andersen's Houston office engaged in aggressive accounting practices, including delayed recognition of publicly available bad news.
Managing Perceptions of Technical Competence: How Well Do Auditors Know How Others View Them?*
Authors: Tan Hun‐Tong , Jamal Karim 
Published: March 2007

AbstractWe investigate factors that influence an auditor's accuracy in knowing how subordinates, peers, and superiors view his or her own technical competence (metaperception). Extant literature on reputation management in auditing contexts depicts preparers of audit workpapers as strategic agents (subordinates) who stylize workpapers and engage in behaviors that enhance their reputations with reviewers (superiors). These superiors, in turn, are represented as strategically engaging in coping behaviors in response to such stylization attempts. One of the necessary conditions for auditors to enhance their reputations on a sustainable basis is accurate metaperception. We report the results of an experiment that investigates determinants of auditors' metaperception accuracy. Our participants comprise teams of audit partners, managers, and seniors who work together in the field. Each auditor performs two tasks of varying complexity and then predicts whether other team members can accurately perform the task and how other team members assess his or her performance on the tasks. Results show that accuracy in knowing what others think of one's technical proficiency (metaperception) is generally high, particularly when the predictor auditors are partners and managers; however, metaperception accuracy is asymmetric and varies depending on the predictor auditor, the target auditor being predicted, and task complexity. Implications are discussed.
Ex Post Voluntary Disclosure Strategies for Insiders*
Authors: Levine Carolyn B. , Smith Michael J. 
Published: March 2007

AbstractAsymmetric information between corporate insiders and other market participants can lead to large bid‐ask spreads or even a collapse of trade in financial markets. In this paper, we discuss how voluntary disclosure by insiders can remedy this problem. When insiders make disclosure decisions after they become informed, other market participants update their prior beliefs on the basis of both the information disclosed and the information not disclosed. Insiders then give up some or all of their information advantage to weakly increase their profits. These results do not rely on ex ante commitments on the part of the insiders.
Sorption of Chromate by Clinoptilolite Modified With Alkylammonium Surfactants
Authors: Bajda Tomasz , Kłapyta Zenon 
Published: March 2007

Sorption of Chromate by Clinoptilolite Modified With Alkylammonium SurfactantsClinoptilolite from Dylągówka (Poland) with an external cation exchange capacity (ECEC) of 16 meq/100 g determined by adsorption of alkylammonium ions was treated with hexadecyltrimethylammonium (C16) and dioctadecyldimethylammonium (2C18) bromides in amounts equivalent to 1.0 and 1.5 ECEC. The products were characterized using IR spectroscopy and C and N determinations. The sorption of chromate on the modified mineral was measured spectrophotometrically as a function of pH, concentration of Cr(VI) or the proportion of the sorbent to solution. The amount of chromate removed from the solution continuously decreased with increasing pH in the range 1.3-10. At pH 2.6-3.1, the maximum adsorption of Cr(VI) by the organo-zeolites (103 and 124 mmol/kg) was observed for the samples modified using a 1.5 ECEC surfactant concentration. Considerably lower adsorption values (37 and 46 mmol/kg) were obtained with sorbents prepared using a 1.0 ECEC concentration of the alkylammonium ions.
Particle size distribution in wort during large scale brewhouse operations
Authors: Kühbeck F. , Back W. , Krottenthaler M. , Kurz T. 
Published: March 2007

AbstractThis investigation highlights the application of particle size distribution measurement in the brewing process steps of mash separation, wort boiling, and wort clarification. Large‐scale trials carried out in seven industrial operations applying different process techniques resulted in the appearance of fine (5 μm), medium (20–25 μm), and coarse particles (>200 μm). During mash separation, the medium and coarse particles were removed while fine particles became dominant and were responsible for the remaining lauter turbidity. Further, prior to start of wort boiling medium particles representing hot trub are formed while the relative portion of fine particles is reduced. This formation is substantially completed when wort boiling temperature is reached, a fact not conforming to current expectations. The coarse particles occurring during wort boiling were identified as originating from hop pellets, while the addition of soluble hop extracts did not cause this signal. Finally, wort clarification by whirlpooling, which is a hydrodynamic separation step, could be described by reduction of coarse and partly of medium particles, while fine particles dominate the resulting wort. The particulate changes observed seem to correlate with chemical analytes conventionally used to characterize these process steps. © 2007 American Institute of Chemical Engineers AIChE J, 2007