bluuebunny/crossref_metadata_2025 huggingface dataset:
An Ensemble Generation Method for Seasonal Forecasting with an Ocean–Atmosphere Coupled Model
Authors: Vialard Jérôme , Vitart Frédéric , Balmaseda Magdalena A. , Stockdale Timothy N. , Anderson David L. T.
Published: March 2005

Seasonal forecasts are subject to various types of errors: amplification of errors in oceanic initial conditions, errors due to the unpredictable nature of the synoptic atmospheric variability, and coupled model error. Ensemble forecasting is usually used in an attempt to sample some or all of these various sources of error. How to build an ensemble forecasting system in the seasonal range remains a largely unexplored area. In this paper, various ensemble generation methodologies for the European Centre for Medium-Range Weather Forecasts (ECMWF) seasonal forecasting system are compared. A series of experiments using wind perturbations (applied when generating the oceanic initial conditions), sea surface temperature (SST) perturbations to those initial conditions, and random perturbation to the atmosphere during the forecast, individually and collectively, is presented and compared with the more usual lagged-average approach. SST perturbations are important during the first 2 months of the forecast to ensure a spread at least equal to the uncertainty level on the SST measure. From month 3 onward, all methods give a similar spread. This spread is significantly smaller than the rms error of the forecasts. There is also no clear link between the spread of the ensemble and the ensemble mean forecast error. These two facts suggest that factors not presently sampled in the ensemble, such as model error, act to limit the forecast skill. Methods that allow sampling of model error, such as multimodel ensembles, should be beneficial to seasonal forecasting.
Measuring International Assignment Return on Investment
Authors: Johnson Lisa
Published: March 2005

With costs for typical three- to five-year international assignments often at prohibitive levels, the justification for sending employees abroad is under scrutiny by global organizations. But in a recent survey of global mobility practitioners, only 14% of the respondents indicated that they had any type of initiative to determine return on investment (ROI). This article examines issues that organizations must consider to measure ROI. The first key area, the need to quantify costs, entails the ability to track associated costs and determine what those costs are. The article also explores direct expenses, administrative expenditures and productivity costs to achieve a balanced view of the equation. Measuring return involves identifying a clear definition of assignment success—an element that not only does not fit a universal standard but also faces inconsistent treatment across organizations in terms of tracking and evaluation. Postassignment career tracking as an additional ROI tool is also discussed.
Avoiding COBRA’s Bite: Three Keys to Compliance
Authors: Dunkelberger Karli
Published: March 2005

Effectively and efficiently managing an organization’s COBRA program is a significant challenge for employers today because of regulatory complexities, legal issues and the risk of financial penalties for noncompliance. Multiple entities are involved in COBRA oversight, and regulations are updated or new rulings issued frequently, creating difficulties in tracking changes and with ensuring compliance. But consequences for non-compliance are costly. IRS penalties alone can include fines of $100 in excise tax per qualified beneficiary, per day, with a $200 per-family maximum. To protect their organizations from fines and ensure compliance with all regulations, employers need to ensure that they understand the law, work to avoid common, yet costly, COBRA mistakes and ensure that the benefit administration process is backed up with performance standards and guarantees. Such standards will protect employers from noncompliance risks, simplify administration and enable human resources professionals to focus their resources on meeting the company’s business objectives.
Opportunity Knocks: Perceptions of Fairness in Employee Benefits
Authors: Cole Nina D. , Flint Douglas H.
Published: March 2005

This article considers potential conflicts between the principles of equity, equality and need in perceptions of fairness regarding employee benefits, based on self-interest bias, and makes specific predictions regarding perceptions of distributive justice in specific benefit plans. It includes predictions regarding perceptions of procedural justice. A survey of 497 employees in seven Canadian organizations tested the predictions. Findings indicate that need is still an important criterion for assessing distributive justice in employee benefits, although the survey also found evidence of self-interest bias. Perceptions of procedural justice were found to be significantly higher in plans with extensive communication and employee participation in plan design. Organizations that take a proactive approach to understanding how employees determine their perceptions of procedural and distributive justice in employee benefits, and design a benefit plan accordingly, can potentially increase employees’ perceptions of justice regarding employee benefits and reap associated benefits including improved employee retention, enhanced ability to hire and increased benefit satisfaction.
Sexual Revictimization
Authors: Classen Catherine C. , Palesh Oxana Gronskaya , Aggarwal Rashi
Published: March 2005

This article reviews the literature on sexual revictimization, covering approximately 90 empirical studies and includes a discussion of prevalence, risk factors, and correlates of sexual revictimization. Research suggests that two of three individuals who are sexually victimized will be revictimized. The occurrence of childhood sexual abuse and its severity are the best documented and researched predictors of sexual revictimization. Multiple traumas, especially childhood physical abuse, and recency of sexual victimization are also associated with higher risk. There is preliminary evidence that membership in some ethnic groups or coming from a dysfunctional family places an individual at a greater risk. Revictimization is associated with higher distress and certain psychiatric disorders. People who were revictimized show difficulty in interpersonal relationships, coping, self-representations, and affect regulation and exhibit greater self-blame and shame. Existing research on prevention efforts and treatment is discussed. More longitudinal studies on sexual revictimization are needed.
Mapping Transformative Learning
Authors: Tosey Paul , Mathison Jane , Michelli Dena
Published: March 2005

This article explores the application of neuro-linguistic programming (NLP) as a framework through which to map transformative learning. This is original work that makes use of NLP as a methodology for inquiring into subjective experience. The authors outline issues in the theory of and research into transformative learning, introduce the field of NLP, then describe the research design for the empirical work, a longitudinal case study of a manager reflecting on experiences of organizational change. Themes resulting from the analysis comprise the following three main categories: characteristics of the output, or of the emergent understanding of the learner; characteristics of the person's inner process or journey; and characteristics of the interpersonal process between learner and facilitator. The article illustrates the application of NLP to the field of transformative learning, providing an example of its potential for empirical investigation.
Is Transformative Learning the Trojan Horse of Western Globalization?
Authors: Bowers C. A.
Published: March 2005

This article raises a number of questions intended to disrupt the “banking process” that now characterizes how the ideas of Freire, Dewey, and critical pedagogy theorists are passed on to the next generation of teacher educators. These questions include: What assumptions are shared by transformative learning theorists and the neoliberals promoting the globalization of the West’s industrial, consumer-dependent culture? Does the hegemonic nature of neoliberalism, with its emphasis on new markets, technologies, and a consumer lifestyle, also require a constant process of transformative learning? Are the silences in the thinking of transformative learning theorists shared by the promoters of Western globalizations—silences about the cultural beliefs and practices that are chief contributors to deepening the ecological crisis and about the ways in which the world’s diverse cultural and environmental commons are being undermined? What is the double bind in transformative learning theories that excludes learning about the commons?
Vitamin E Trafficking
Authors: TRABER MARET G. , BURTON GRAHAM W. , HAMILTON ROBERT L.
Published: March 2005

Abstract: The α‐tocopherol transfer protein (α‐TTP) is required to prevent vitamin E deficiency in humans and in α‐TTP null mice. Whereas α‐TTP is not required to facilitate intestinal absorption of vitamin E, it is required to maintain normal α‐tocopherol concentrations in plasma and extrahepatic tissues. α‐Tocopherol secretion from the liver in very low density lipoproteins (VLDLs) is impaired in humans with a defect in the α‐TTP gene. In perfusions of isolated cynomolgus monkey livers, VLDLs were preferentially enriched in RRR‐α‐tocopherol. The mechanism by which α‐TTP incorporates α‐tocopherol into nascent VLDLs is the topic of this report. VLDL assembly is a multistep secretory process that occurs within the membrane compartments of the endoplasmic reticulum and Golgi apparatus. Thus, we postulated that α‐TTP might transfer α‐tocopherol onto nascent VLDLs either in the endoplasmic reticulum or in the Golgi apparatus. To test these possibilities, we isolated nascent VLDLs from highly purified RER and Golgi apparatus membrane fractions from livers of rats fed equimolar ratios of RRR‐ and SRR‐α‐tocopherols labeled with different amounts of deuterium. Although the plasma was enriched in RRR‐α‐tocopherol 14 hours after the dose, no enrichment of nascent VLDL precursors from either of the secretory compartments was detected, indicating that VLDL enrichment with α‐tocopherol may occur as a post‐VLDL secretory process. Therefore, we hypothesize that α‐TTP may facilitate movement of α‐tocopherol to the hepatocyte plasma membrane (by unknown mechanisms) where newly secreted, nascent VLDLs could acquire both α‐tocopherol and unesterified cholesterol while within the space of Disse. Clearly, critical information is lacking in our understanding of the mechanism by which α‐TTP facilitates the preferential enrichment of VLDLs with α‐tocopherol.
Discovery, Characterization, and Significance of the Cytochrome P450 ω‐Hydroxylase Pathway of Vitamin E Catabolism
Authors: PARKER ROBERT S. , SONTAG TIMOTHY J. , SWANSON JOY E. , McCORMICK CHARLES C.
Published: March 2005

Abstract: Tocopherols are known to undergo metabolism to phytyl chain‐shortened metabolites excreted in urine. We sought to characterize the pathway, including associated enzymes, involved in this biotransformation. We previously found that human hepatoblastoma (HepG2) cultures metabolized tocopherols to their corresponding short‐chain carboxychromanols. Putative metabolites of γ‐tocopherol that contained intact chromanol moieties were structurally identified using HepG2 cultures and electron impact gas chromatography‐mass spectrometry. A microsomal assay for synthesis of the initial ω‐oxidation metabolites was developed and used to screen several recombinant human liver cytochrome P450 isozymes for ω‐hydroxylase activity. Seven metabolites of γ‐tocopherol were identified in HepG2 cultures, including 13′‐hydroxy‐γ‐TOH and all six carboxychromanols predicted by sequential ω‐oxidation truncation. Rat and human liver microsomes catalyzed synthesis of 13′‐OH‐ and 13′‐COOH‐γ‐TOH, but not other metabolites, in the presence of NADPH. Inclusion of NAD favored synthesis of the 13′‐COOH metabolite. Recombinant CYP4F2, but not other major human liver CYP isoforms (including CYP3A4 and 3A7), exhibited tocopherol‐ω‐hydroxylase activity. Liver microsomes and recombinant CYP4F2 both exhibited substrate preference for γ‐TOH over α‐TOH, and recent studies show that tocotrienols are catabolized more extensively than the corresponding tocopherols. Comparative rates of ω‐oxidation of tocochromanols in hepatocytes are inversely related to biopotency and directly related to cytotoxicity of these substances in macrophages. The liver contains a cytochrome P450‐mediated pathway that preferentially catabolizes “non‐α” tocochromanols to excretable metabolites. This metabolic pathway appears central to the optimization of tissue tocochromanol status.
Molecular Mechanisms of Vitamin E Transport
Authors: STOCKER ACHIM
Published: March 2005

Abstract:Vitamin E is the most important lipid‐soluble antioxidant in humans. Specific tocopherol‐binding proteins favor the retention of the most potent vitamin E homologue, RRR‐α‐tocopherol (RRR‐α‐T) in man. The crystal structures of both the ligand‐charged and the apo‐forms of human α‐tocopherol transfer protein (α‐TTP) and of human supernatant protein factor (SPF) have been solved. The renewed interest in the biological function of tocopherol binders is based on the discovery of ataxia with vitamin E deficiency, a neurological disorder that is caused by genetic defects of the α‐TTP gene and/or vitamin E deficiency. The analysis of the crystal structure of α‐TTP provides the molecular basis of vitamin E retention in man. SPF has been reported to enhance cholesterol biosynthesis by facilitating the conversion of squalene to lanosterol. Nevertheless, the physiological role of SPF as well as its ligand specificity is not known. Investigations on the substrate specificity of SPF have uncovered binding of RRR‐α‐tocopherylquinone (RRR‐α‐TQ). RRR‐α‐TQ represents the major physiological oxidation product of RRR‐α‐T. The three‐dimensional overlay of the ligand‐charged structures of SPF and α‐TTP indicates that ligand specificity in both proteins is mostly modulated by side‐chain variations rather than by the backbone. Recent reports point towards thein vivoreduction of RRR‐α‐TQ to RRR‐α‐TQH2and its protective role in low‐density lipoprotein oxidation. On the basis of these reports, it is proposed that SPF may enhance cholesterol biosynthesis indirectly by mediating the transfer of RRR‐α‐TQ to low‐density lipoprotein, thus reducing oxidation of low‐density lipoprotein and its subsequent cellular uptake by scavenger receptors.
Physiological Factors Influencing Vitamin E Biokinetics
Authors: LODGE JOHN K. , HALL WENDY L. , JEANES YVONNE M. , PROTEGGENTE ANNA R.
Published: March 2005

Abstract: Limited information is available on factors that can influence vitamin E bioavailability. In several studies we have investigated the influence of dietary, biochemical, and genetic factors on vitamin E biokinetics. In these studies, subjects ingested a capsule containing 150 mg deuterated RRR‐α‐tocopheryl acetate, blood was taken up to 48 hr, and tocopherols were analyzed by liquid chromatography and mass spectroscopy. There was significantly greater plasma‐labeled α‐tocopherol concentrations when the capsule was consumed with a high‐fat meal (17.5 g) versus a low‐fat meal (2.7 g), and there was also a difference between a high‐fat toast and butter and a cereal with full‐fat milk meal (both 17.5 g fat), indicating that both the amount of fat and food matrix is important for vitamin E absorption. Dyslipidemic subjects displayed a reduced plasma uptake of newly absorbed α‐tocopherol, and differences were also apparent in individual lipoproteins. A decreased uptake of labeled α‐tocopherol was also observed in erythrocytes, platelets, and lymphocytes of dyslipidemics. Following vitamin E supplementation (400 mg/day, 4 weeks), the uptake of newly absorbed α‐tocopherol was decreased, presumably because of saturation of α‐tocopherol transfer protein. We also found that apoE3 subjects displayed a considerably reduced uptake of newly absorbed labeled α‐tocopherol compared to apoE4 subjects, which may be a consequence of the reduced low‐density lipoprotein catabolic rate in these subjects. Taken together, these data show that several physiological factors influence the uptake of newly absorbed α‐tocopherol, and that this is an important consideration in the design of future vitamin E supplementation studies.
Vitamin E in Neurodegenerative Disorders: Alzheimer's Disease
Authors: KONTUSH ANATOL , SCHEKATOLINA SVETLANA
Published: March 2005

Abstract: Oxidative stress is important in the pathogenesis of Alzheimer's disease (AD). The brain contains high levels of oxidizable lipids that must be protected by antioxidants. Low concentrations of vitamin E, quantitatively the major lipophilic antioxidant in the brain, are frequently observed in cerebrospinal fluid (CSF) of AD patients, suggesting that supplementation with vitamin E might delay the development of AD. In a placebo‐controlled trial, vitamin E (2000 IU/day, 2 years) slowed (−53%) functional deterioration in patients with moderate AD (Sano et al., N. Engl. J. Med. 336: 1216‐1222, 1997). Recently, use of vitamin E and vitamin C supplements in combination was found to be associated with reduced prevalence (−78%) and incidence (−64%) of AD in elderly population (Zandi et al., Arch. Neurol. 61: 82‐88, 2004). These results are consistent with the ability of the supplementation with vitamin E (400 IU/day, 1 month) to increase its levels in CSF (123%) and plasma (145%) of AD patients and, in combination with vitamin C (1000 g/day), to decrease the susceptibility of CSF lipoproteins (up to −32%) to in vitro oxidation (Kontush et al., Free Radic. Biol. Med. 31: 345‐354, 2001). In addition, vitamin E reduced lipid peroxidation and amyloid deposition in a transgenic mice model of AD (Sung et al., FASEB J. 18: 323‐325, 2004). Computer modeling of the influence of vitamin E on lipoprotein oxidation reveals that the vitamin develops antioxidative activity in CSF lipoproteins in the presence of physiologically relevant, low amounts of oxidants. By contrast, under similar conditions, vitamin E behaves as a pro‐oxidant in plasma lipoproteins, consistent with the model of tocopherol‐mediated peroxidation (Stocker, Curr. Opin. Lipidol. 5: 422‐433, 1994). This distinction is related to major differences in the levels of vitamin E (50 nM vs. 30 μM) and oxidizable lipids (4 μM vs. 2.5 mM) between CSF and plasma, which result in major differences in oxidative conditions (per unit of vitamin E) between CSF and plasma in the presence of similar amounts of oxidants. Altogether, these data suggest that vitamin E may be effective against in vivo oxidation of CSF lipoproteins and brain lipids, and offer new perspectives in the treatment of AD and other neurodegenerative disorders.
Vitamin E in Neural and Visual Function
Authors: HAYTON S M , MULLER D P R
Published: March 2005

Abstract: A rat model of vitamin E (α‐tocopherol) deficiency with similar “clinical,” electrophysiological, and neuropathological abnormalities to those seen in man was used to investigate the effects of various amounts and forms of α‐tocopheryl acetate (αTA) on neural and visual function. Electrophysiological techniques provide an objective, non‐invasive measure of neural and visual function. These techniques were used in the animal model to determine the minimum dietary requirement of vitamin E necessary to prevent neural and visual abnormalities. They were also used to compare the biological activities of the natural (RRR‐) and synthetic (all‐rac‐) forms of α‐tocopherol in neural tissues. The results were as follows: (1) Significant differences in neural and visual function were observed between deficient and control rats after approximately 8 months. (2) An intake of 1.0 mg/kg all‐rac‐ or 0.75 mg/kg RRR‐αTA was observed to marginally protect nerves from vitamin E deficiency. (3) The biological activity of all‐rac‐α‐tocopherol in neural tissues was approximately 75% of RRR‐α‐tocopherol. (4) The concentration of free malondialdehyde (an indicator of lipid peroxidation) was significantly increased in tissues from the deficient compared to the control animals. These results are consistent with a deficiency of α‐tocopherol causing increased lipid peroxidation leading to abnormal neural electrophysiology. They could also be explained by more specific but as yet undefined function(s) of α‐tocopherol in neural tissues.
Vitamin E Modulation of Cardiovascular Disease
Authors: MEYDANI MOHSEN
Published: March 2005

Abstract: Endothelium in the vascular system is an important modulator of vasomotor tone and coagulation, and it plays a crucial role in the inhibition of adhesion and activation of platelets and leukocytes. Evidence indicates that dietary antioxidants may modulate these endothelium‐dependent vascular functions through several mechanisms and may contribute to the prevention of vascular diseases such as atherosclerosis. Several cell cultures as well as animal and human clinical and observational studies have tested the efficacy of vitamin E on vascular function and the prevention of atherosclerosis. Our cell culture studies have indicated that vitamin E (α‐tocopherol) inhibits the activation of endothelial cells stimulated by high levels of low‐density lipoprotein cholesterol and pro‐inflammatory cytokines. This inhibition is associated with the suppression of chemokines, the expression of cell surface adhesion molecules, and the adhesion of leukocytes to endothelial cells, all of which contribute to the development of lesions in the arterial wall. The molecular mechanisms by which α‐tocopherol and other tocopherols modulate endothelial cells and smooth muscle functions have been delineated. We, and others, have also demonstrated a positive effect of dietary vitamin E on endothelium and vascular function in animal models of atherosclerosis. Several human clinical trials have also shown an improvement in the surrogate markers of atherosclerosis and vascular function by vitamin E supplementation. However, these findings have been contradicted by several vitamin E supplementation trials for the prevention of secondary cardiovascular events showing null effect. Intervention at a relatively late stage of disease and the single use of vitamin E rather than in combination with other antioxidants might have contributed to these contradictory findings. Evidence from cell cultures, as well as animal and human clinical and observational studies, strongly supports the contribution of dietary vitamin E to the maintenance of vascular function and health, in particular when it is used in combination with other dietary antioxidants, which are found in fruits, vegetables, and nuts.
Vitamin E and Cardiovascular Disease: Observational Studies
Authors: GAZIANO J MICHAEL
Published: March 2005

Abstract: Basic research suggests that oxidative stress may play an important role in many chronic diseases and provides plausible mechanisms by which natural antioxidants such as vitamin E may delay or prevent steps in atherogenesis. Dietary research has shown that those who consume higher amounts of fruits and vegetables have lower rates of heart disease and stroke, raising the possibility that antioxidants are protective. Results from large‐scale human observational studies suggest that antioxidant consumption reduces the risk of developing cardiovascular disease (CVD). Both case‐control and prospective cohort studies have carefully explored the relationship between vitamin E intake and plasma and tissue vitamin E levels and the risk of CVD. In many, but not all, of these studies vitamin E intake over an extended period was associated with decreased risk of cardiovascular events. Results from studies of blood levels are more limited and less consistent. This presentation summarizes data from the major observational studies. Overall, they support the possibility that vitamin E intake either from food or supplements may reduce risk of CVD; however, these studies have important limitations. For example, uncontrolled confounding can be similar in magnitude to the observed health effects, and antioxidant consumption may be merely a marker for a different cardioprotective factor (such as exercise or diet) that is responsible for these effects. In the search for small to moderate effects, randomized trials may be helpful, although to date, data from large‐scale trials have been inconsistent. Several large‐scale trials currently under way will help identify the potential benefits of vitamin E in the primary prevention of CVD and other chronic illness. Some are designed to test vitamin E alone as well as in combination with other antioxidant supplements because it is possible that antioxidants may be most effective if taken in particular combinations. Currently, the American Heart Association maintains that there are insufficient efficacy data from completed randomized trials to justify population‐wide recommendations for use of vitamin E supplements in disease prevention.
α‐Tocopherol Affects Androgen Metabolism in Male Rat
Authors: BARELLA LUCA , ROTA CRISTINA , STÖCKLIN ELISABETH , RIMBACH GERALD
Published: March 2005

Abstract: The Alpha‐Tocopherol Beta‐Carotene Cancer Prevention Study has provided the first evidence implicating vitamin E in hormone synthesis. The effect of vitamin E on stereoidogenesis in testes and adrenal glands was assessed in growing rats using Affymetrix gene‐chip technology. Dietary supplementation of rats with vitamin E (60 mg/kg feed) for a period of 429 days caused a significant repression of genes encoding for proteins centrally involved in the uptake (low‐density lipoprotein receptor) and de novo synthesis (for example, 7‐dehydrocholesterol reductase, 3‐hydroxy‐3‐methylglutaryl coenzyme A synthase, 3‐hydroxy‐3‐methylglutaryl‐coenzyme A reductase, isopentenyl‐diphosphate delta‐isomerase, and farnesyl pyrophosphate synthetase) of cholesterol, the precursor of all steroid hormones. The present investigation indicates that dietary vitamin E may induce changes in stereoidogenesis by affecting cholesterol homeostasis.
Effects of Vitamin E Depletion/Repletion on Biomarkers of Oxidative Stress in Healthy Aging
Authors: WINKLHOFER‐ROOB BRIGITTE M. , MEINITZER ANDREAS , MARITSCHNEGG MICHAELA , ROOB JOHANNES M. , KHOSCHSORUR GHOLAMALI , RIBALTA JOSEP , SUNDL ISABELLA , WUGA SANDRA , WONISCH WILLIBALD , TIRAN BEATE , ROCK EDMOND ,   VITAGE STUDY GROUP
Published: March 2005

Abstract: The effects on ex vivo LDL resistance to oxidation and biomarkers of in vivo oxidative stress in response to 3‐month dietary vitamin E restriction to 25% of recommended intake and 2‐month unrestricted dietary intake and supplementation with 800 IU/d were studied in 100 healthy, nonsmoking 20‐75‐year‐old volunteers. Significant changes in vitamin E status were associated with decreases and increases, respectively, in LDL resistance to oxidation in the depletion and supplementation period and with decreases in lipid peroxidation and oxidative DNA modification in the supplementation period. Healthy aging was not associated with enhanced susceptibility to oxidation in the depletion period.
The Decrease in γ‐Tocopherol in Plasma and Lipoprotein Fractions Levels Off within Two Days of Vitamin E Supplementation
Authors: SUNDL ISABELLA , RESCH ULRIKE , BERGMANN ANDREAS R. , ROOB JOHANNES M. , WINKLHOFER‐ROOB BRIGITTE M.
Published: March 2005

Abstract: The effects of vitamin E supplementation on α‐ and γ‐tocopherol concentrations were studied in plasma and lipoprotein fractions of five healthy volunteers taking 1000 IU/day of RRR α‐tocopherol for 4 days. Although plasma α‐tocopherol increased, γ‐tocopherol decreased. Compared with baseline, γ‐/α‐tocopherol ratios decreased from 48 h onward (P < 0.001). They all leveled off within 48 h. From 12 h onward, γ‐/α‐tocopherol ratios were higher in VLDL and IDL than in LDL and HDL, indicating that γ‐tocopherol is better maintained in triglyceride‐rich lipoprotein fractions. These data suggest that vitamin E supplementation exceeding 2 days does not further decrease γ‐tocopherol concentrations.
Does Aging Affect the Response of Vitamin E Status to Vitamin E Depletion and Supplementation?
Authors: WINKLHOFER‐ROOB BRIGITTE M. , ROOB JOHANNES M. , MARITSCHNEGG MICHAELA , SPRINZ GRETE , HILLER DORIS , MARKTFELDER ELISABETH , PREINSBERGER MELANIE , WUGA SANDRA , SUNDL ISABELLA , TIRAN BEATE , CARDINAULT NICOLAS , RIBALTA JOSEP , ROCK EDMOND ,   VITAGE STUDY GROUP
Published: March 2005

Abstract: A vitamin E depletion/supplementation study was conducted in 100 healthy 20‐75‐year‐old volunteers. The responses of vitamin E status to 3‐week dietary vitamin E restriction to approximately 25% of recommended intake and 2‐month unrestricted dietary intake plus 800 IU/d of RRR‐α‐tocopherol were studied as a function of age. Plasma α‐tocopherol concentrations were closely related to cholesterol concentrations, which increased with age (P < 0.001). Upon dietary restriction, plasma α‐tocopherol concentrations decreased significantly (P < 0.001) but independently of age. Plasma α‐tocopherol responses to supplementation increased significantly with age, but this effect disappeared after standardization for cholesterol. γ‐Tocopherol concentrations decreased to less than 30% of baseline.
γ‐Tocotrienol Metabolism and Antiproliferative Effect in Prostate Cancer Cells
Authors: CONTE CARMELA , FLORIDI ALESSANDRO , AISA CRISTINA , PIRODDI MARTA , FLORIDI ARDESIO , GALLI FRANCESCO
Published: March 2005

Abstract: In this study, we evaluated the antiproliferative effect of tocotrienols (T3) and the presence of a specific vitamin E metabolism in PC3 and LNCaP prostate cancer cells. These cell lines are able to transform tocopherols (T) and T3 in the corresponding carboxyethyl‐hydroxychromans metabolites (CEHCs). The extent of this metabolism and the inhibitory effect on cell growth followed the order of magnitude α‐T<α‐T3<γ‐T<γ‐T3. The partial inhibition of γ‐T3 metabolism by ketoconazole did not influence cell proliferation. These early findings may suggest that the transformation of vitamin E to CEHC is mostly a detoxification mechanism useful to maintain the malignant properties of prostate cancer cells.
Vitamin E Supplementation Reverses the Age‐Associated Decrease in Effective Immune Synapse Formation in CD4+ T Cells
Authors: AHMED TANVIR , MARKO MELISSA , WU DAYONG , CHUNG HEEKYUNG , HUBER BRIGITTE , MEYDANI SIMIN NIKBIN
Published: March 2005

Abstract: Aging is associated with impairment of T cell function. We demonstrate here that age‐associated declines in T cell signaling are due to the inability to form effective immune synapses at the site of the T cell receptor and antigen interaction. On the basis of our previous research with vitamin E (VE), we hypothesized that VE supplementation of old CD4+ T cells enhances effective immune synapse formation through increased translocation of signaling proteins. Using confocal microscopy, we found that when exposed to antigen‐presenting cells, CD4+ T cells from old mice have a lower percentage of effective immune synapses compared to those from young mice. Furthermore, we show that in vitro and in vivo VE supplementation increases the percentage of old CD4+ T cells capable of forming a functional immune synapse. Further studies are under way to determine the mechanisms of age and VE‐induced enhancement of effective immune synapse formation.
Tocopherol in Lipoproteins and Blood Cells after Cardiac Surgery
Authors: HACQUEBARD M , DUCART A , SCHMARTZ D , TEMBO N , CARPENTIER Y A
Published: March 2005

Abstract: Cardiac surgery was associated with a marked reduction in circulating LDL and HDL particles, which in turn largely affectd α‐toc transport. α‐toc was decreased in WBCs but not in PLTs and RBCs. An increased hydroperoxide content was observed in LDL and possibly in HDL after cardiac surgery.
Direct regulation ofknotgene expression by Ultrabithorax and the evolution of cis-regulatory elements inDrosophila
Authors: Hersh Bradley M. , Carroll Sean B.
Published: March 2005

The regulation of development by Hox proteins is important in the evolution of animal morphology, but how the regulatory sequences of Hox-regulated target genes function and evolve is unclear. To understand the regulatory organization and evolution of a Hox target gene, we have identified a wing-specific cis-regulatory element controlling the knot gene, which is expressed in the developing Drosophila wing but not the haltere. This regulatory element contains a single binding site that is crucial for activation by the transcription factor Cubitus interruptus (Ci), and a cluster of binding sites for repression by the Hox protein Ultrabithorax (UBX). The negative and positive control regions are physically separable, demonstrating that UBX does not repress by competing for occupancy of Ci-binding sites. Although knot expression is conserved among Drosophilaspecies, this cluster of UBX binding sites is not. We isolated the knot wing cis-regulatory element from D. pseudoobscura,which contains a cluster of UBX-binding sites that is not homologous to the functionally defined D. melanogaster cluster. It is, however,homologous to a second D. melanogaster region containing a cluster of UBX sites that can also function as a repressor element. Thus, the knot regulatory region in D. melanogaster has two apparently functionally redundant blocks of sequences for repression by UBX, both of which are widely separated from activator sequences. This redundancy suggests that the complete evolutionary unit of regulatory control is larger than the minimal experimentally defined control element. The span of regulatory sequences upon which selection acts may, in general, be more expansive and less modular than functional studies of these elements have previously indicated.
Microenvironments in Faujasite-type Fe–Al Zeolites Probed by Europium Luminescence
Authors: Nakamura Yasushi , Hasaegawa Masatoshi , Katsuki Kazuko
Published: March 2005

Europium was introduced into faujasite-type zeolites through ion exchange. The intensity ratio of the emission bands peaking at 590 and 614 nm changed depending on the amount of adsorbed water in zeolites. The results suggest that europium photoluminescence spectra could be a useful probe for providing information on a microenvironment in hydrated zeolites. The europium luminescence spectra of Fe–Al faujasite were measured as a function of the Fe content and compared with the water desorption temperatures to discuss the effect of Fe incorporation into the zeolite framework.
Synthesis, Structure, and Fluxional Behavior of κ1-O-Enolatoiron(II) Complexes Derived from 1,3-Dicarbonyl Compounds
Authors: Kiyota Sayori , Tamuki Jun-ichi , Komine Nobuyuki , Hirano Masafumi , Komiya Sanshiro
Published: March 2005

Highly nucleophilic κ1-O-enolatoiron(II) complexes trans-FeH(OCR1CHCOR2-κ1O)(DEPE)2 (1a: R1 = R2 = Me, 1b: R1 = R2 = OMe, 1c: R1 = Me, R2 = OMe) are prepared by the reaction of Fe(N2)(DEPE)2 with 1,3-dicarbonyl compounds.
Stereoselective Synthesis of trans-3,4-Dihydropyran-2-ones by Phenoxide ion-catalyzed Tandem Michael Addition and Lactonization
Authors: Tozawa Takashi , Yamane Yoshinobu , Mukaiyama Teruaki
Published: March 2005

Phenoxide ion-catalyzed tandem Michael addition and lactonization between α,β-unsaturated ketones and silyl enolates derived from phenyl carboxylates proceeded smoothly to afford the corresponding 3,4-dihydropyran-2-ones in high yields with good to excellent trans-selectivities.
A Stable Hexagonal Mesoporous Aluminophosphate Assembled from Preformed Aluminophosphate Precursors
Authors: Lin Kaifeng , Wang Lifeng , Sun Zhenhua , Yang Qing , Di Yan , Zhang Daliang , Jiang Dazhen , Xiao Feng-Shou
Published: March 2005

A hexagonal mesoporous aluminophosphate with high thermal stability (JLU-50) is successfully synthesized from the assembly of preformed aluminophosphate precursors with a cationic surfactant cetyltrimethylammonium bromide (CTAB) by a two-step procedure.
The High Thermoelectric Properties of Conducting Polyaniline with Special Submicron-fibre Structure
Authors: Yao Qin , Chen Lidong , Xu Xiaochuan , Wang Chunfen
Published: March 2005

Thermoelectric properties of camphorsulfonic acid (CSA) doped conducting polyaniline with different structures have been studied. The sample with special submicron-fibre structure exhibited 20 times higher thermoelectric power factor at 300 K than the sample with general grain structure, which could be ascribed to its higher carrier mobility caused by its higher order of chain packing.
Canine Hepatic Neuroendocrine Carcinoma: An Immunohistochemical and Electron Microscopic Study
Authors: Patnaik A. K. , Newman S. J. , Scase T. , Erlandson R. A. , Antonescu C. , Craft D. , Bergman P. J.
Published: March 2005

Ten dogs with neuroendocrine carcinoma of the liver were selected for inclusion in the study. Clinical signs were anorexia (7), vomiting (5), polydipsia/polyuria (3), icterus (2), lethargy (2), weight loss (2), paresis (1), ataxia (1), weakness (1), collapse (1), and urinary tract infection (1). Hematologic and biochemical abnormalities included anemia (2/8), leukocytosis (4/8), high liver enzyme activity (serum alkaline phosphatase, 7/9; alanine transaminase, 7/9; aspartate transaminase, 8/9), and high total bilirubin (6/9). Grossly, the tumors were diffuse, involving all liver lobes in six dogs, and two dogs had various-sized nodules in addition to diffuse involvement. Histologically, there were eight tumors with solid or trabecular pattern (group A), one tumor with cords or rows of neoplastic cells (group B), and one tumor with multiple rosette-like structures (group C). immunohistochemical studies revealed that all 10 neoplasms were positive for at least one of the endocrine markers used: neuron-specific enolase (NSE; 8/10), synaptophysin (5/10), and chromogranin-A (3/10). A panel of NSE, chromagranin-A, and synaptophysin detected 100% of the tumors in our series. Electron microscopy confirmed the diagnosis by the presence of intracytoplasmic neurosecretory granules in the two examined cases. our results show that neuroendocrine markers commonly used in humans can be used for the diagnosis of hepatic neuroendocrine carcinoma in dogs, preferably a panel of synaptophysin, chromagranin-A, and NSE because chromogranin-A alone is not as useful in dogs as in humans.
Pathology of Domoic Acid Toxicity in California Sea Lions (Zalophus californianus)
Authors: Silvagni P. A. , Lowenstine L. J. , Spraker T. , Lipscomb T. P. , Gulland F. M. D.
Published: March 2005

Over 100 free-ranging adult California sea lions ( Zalophus californianus) and one Northern fur seal ( Callorhinus ursinus), predominantly adult females, were intoxicated by domoic acid (DA) during three harmful algal blooms between 1998 and 2000 in central and northern California coastal waters. The vector prey item was Northern anchovy ( Engraulis mordax) and the primary DA-producing algal diatom was Psuedonitzschia australis. Postmortem examination revealed gross and histologic findings that were distinctive and aided in diagnosis. A total of 109 sea lions were examined, dying between 1 day and 10 months after admission to a marine mammal rehabilitation center. Persistent seizures with obtundation were the main clinical findings. Frequent gross findings in animals dying acutely consisted of piriform lobe malacia, myocardial pallor, bronchopneumonia, and complications related to pregnancy. Gross findings in animals dying months after intoxication included bilateral hippocampal atrophy. Histologic observations implicated limbic system seizure injury consistent with excitotoxin exposure. Peracutely, there was microvesicular hydropic degeneration within the neuropil of the hippocampus, amygdala, pyriform lobe, and other limbic structures. Acutely, there was ischemic neuronal necrosis, particularly apparent in the granular cells of the dentate gyrus and the pyramidal cells within the hippocampus cornu ammonis (CA) sectors CA4, CA3, and CA1. Dentate granular cell necrosis has not been reported in human or experimental animal DA toxicity and may be unique to sea lions. Chronically, there was gliosis, mild nonsuppurative inflammation, and loss of laminar organization in affected areas.
Hepatocellular Carcinoma with Metastasis to the Spleen in a Holstein Cow
Authors: Jeong W. I. , Do S. H. , Sohn M. H. , Yun H. S. , Kwon O. D. , Kim T. H. , Jeong D. H. , Williams B. H. , Jeong K. S.
Published: March 2005

Hepatocellular carcinoma (HCC) with metastasis to the spleen in a Holstein cow was studied by histopathologic and immunohistochemical methods. The tumor was characterized by a pseudoglandular (acinar) pattern with an associated fibrous stroma. Individual cells often had a “hepatoid” appearance but were interspersed with scattered cells exhibiting a clear, periodic acid-Schiff (PAS)-positive cytoplasm and small eccentric nuclei. This pattern was present in nodules found in both liver and spleen. Moreover, hepatoid tumor cells were positive for alpha-fetoprotein. Immunohistochemical studies suggest that myofibroblasts were responsible for the production of fibrous septa surrounding the pseudoglandular structures of bovine HCC. In summary, our histologic and immunohistochemical findings support a diagnosis of primary HCC with splenic metastasis. Furthermore, the associated stromal response appears to be of a myofibroblast origin. The primary etiology of bovine HCC and the significance of the intralesional, PAS-positive clear cells remain undetermined.
Management Ownership and Audit Firm Size*
Authors: LENNOX CLIVE
Published: March 2005

The finance literature identifies two agency problems between managers and outside shareholders. First, there is a divergence‐of‐interests problem as management ownership falls. Second, there is an offsetting entrenchment problem when management ownership increases within intermediate regions of ownership. Agency problems are mitigated through contracting, but contracts are often based on accounting numbers prepared by management. Because accounting numbers must be reliable for contracts to be enforced, agency theory predicts a demand for higher‐quality auditors when agency problems are more severe. However, extant studies find no significant or robust relation between management ownership and audit firm size. In contrast to extant research, this study samples unlisted companies rather than listed companies for two reasons. First, the monitoring value of auditing may be higher in unlisted companies because they are less vulnerable to takeover and they are required to disclose much less nonaccounting information to shareholders. Second, unlisted companies have greater variation in management ownership, which permits more powerful tests of the demand for auditing as ownership varies between 0 percent and 100 percent. Consistent with a divergence‐of‐interests effect, the association between management ownership and audit firm size is found to be significantly negative within low and high regions of management ownership. The association is flatter and slightly positive within intermediate regions of management ownership, suggesting the existence of an opposite entrenchment effect. The negative association and the nonlinearity is consistent with the finance literature and with the predictions of agency theory.
Longitudinal Study of Periodontal Disease and Edentulism With Rates of Bone Loss in Older Women
Authors: Famili P. , Cauley J. , Suzuki J.B. , Weyant R.
Published: March 2005

Background: Previous cross‐sectional studies have suggested a link between periodontal disease and osteoporosis. The purpose of the present study is to evaluate the association between changes in bone mineral density (BMD) and clinical signs of periodontal tissue destruction and tooth loss over a 2‐year period.

Methods: A total of 398 women (mean age 75.5 years) were randomly selected for an ancillary study of periodontal disease; osteoporosis in association with the presence or absence of teeth was evaluated. Osteoporosis in association with periodontal disease was also evaluated. All subjects were participants at the Pittsburgh Clinical Center for the Study of Osteoporotic Fractures (SOF), a prospective cohort study of women 65 years of age or older designed to determine risk factors for fractures. Oral health examinations, including periodontal probing and attachment loss, were performed at the fourth clinical visit, an average of 6 years after baseline. BMD of the total hip and its subregions was measured using dual energy x‐ray absorptiometry at the time of dental examination and 2 years later. Results are expressed as annual percentage change.

Results: A total of 145 (36.4%) women were edentulous and 163 (80.7%) of the dentate women (N = 253) had periodontal disease. Dentate women reported higher education (P <0.001) and a higher calcium intake (P = 0.002). Absolute BMD and percentage change in BMD were similar in dentate and edentulous women. We found no difference in BMD or in absolute or percentage change in BMD between women with or without periodontal disease.

Conclusion: Little evidence exists for an association between edentulousness, periodontal disease, and longitudinal changes in BMD. J Periodontol 2005;76:11‐15.
Reconstitution of a Hyperinflammatory Prostaglandin E2 Response to Porphyromonas gingivalis Challenge in Severe Combined Immunodeficient Mice
Authors: Salvi Giovanni E. , Spets‐Happonen Satu , Singer Robert E. , Offenbacher Steven
Published: March 2005

Background: The purpose of this study was to determine whether lymphocytic cells regulate the monocytic hyperinflammatory trait (MO+) in chronic periodontitis patients. Using a P. gingivalis challenge model in severe combined immunodeficient (SCID) mice, we tested the effects of adoptively transferred human peripheral blood leukocytes from gingivitis and chronic periodontitis diabetic and non‐diabetic individuals on monocytic responses.

Methods: This response was examined using the subcutaneous tissue chamber infection model. Three weeks following cell reconstitution, all SCID mice were challenged with 109 colony forming units of live P. gingivalis HG405. Chamber contents were collected at day 7 after bacterial challenge for prostaglandin E2 (PGE2) analysis and chamber rejection monitored up to day 30. Gingival crevicular fluid (GCF) samples were collected from all patients for PGE2 analysis. Both chamber fluid‐ and GCF‐PGE2 levels were determined by enzyme‐linked immunosorbent assays (ELISA).

Results: Significantly elevated GCF‐PGE2 levels were found in diabetic as well as in non‐diabetic patients with moderate/advanced periodontitis compared to diabetic and non‐diabetic subjects with gingivitis/mild periodontitis at P = 0.01 and P = 0.001, respectively. As reflected in chamber fluid PGE2 levels and percentage chamber rejection, lymphocytic sensitization to P. gingivalis occurred in both diabetics and non‐diabetics with moderate/advanced periodontitis, but not in diabetics and non‐diabetics with gingivitis/mild periodontitis.

Conclusions: These results suggest that the exaggerated monocytic inflammatory response trait (MO+) associated with moderate/ advanced chronic periodontitis is due, at least in part, to lymphocytic modulation, while the directional findings for lymphocytes from diabetic subjects deserve further investigation. Our findings further demonstrate that the SCID mouse model is a useful animal model to study human immune responses to periodontal microorganisms. J Periodontol 2005;76:16‐21.