bluuebunny/crossref_metadata_2025 huggingface dataset:
Towards health-promoting and environmentally friendly regional diets – a Nordic example
Authors: Bere Elling , Brug Johannes
Published: March 2008

Background

Because most of the top determinants of the worldwide burden of disease are diet-related, the promotion of healthful diets is important for population health across the world. Furthermore, changes in eating habits may contribute to preservation of the environment.

Objective

In the present paper it is argued that the translation of health-promoting dietary recommendations into practical recommendations for healthful eating should be more tailored to regional circumstances. This will promote population health as well as help preserve cultural diversity in eating habits and contribute to more environmentally friendly eating. A regional Nordic diet, mimicking the Mediterranean diet to some extent, is presented as an example.

Conclusion

A theoretically health-enhancing Nordic diet is possible including six evidence-based ingredients: (i) native berries; (ii) cabbage; (iii) native fish and other seafood; (iv) wild (and pasture-fed) land-based animals; (v) rapeseed oil; and (vi) oat/barley/rye.
American Muslim Political Participation Following 9/11: Religious Belief, Political Resources, Social Structures, and Political Awareness
Authors: Ayers John W. , Hofstetter C. Richard
Published: March 2008

Using a nationwide survey of American Muslims conducted in 2004, we evaluate models of political participation, specifically the influence of religious characteristics, political resources, social structures, and political awareness on Muslims' reported political participation. American Muslims reported extremely high rates of political participation in comparison to the general public and in this regard are model citizens. Using path analysis, our findings concluded that religious beliefs were negatively associated with political participation, while measures of religious resources were positively related to participation. Social structures had mixed influence in most cases statistically indistinguishable from zero. Political resources and measures of political awareness, specifically feelings of anxiety following 9/11, were positively associated with participation.
Christian Right Horticulture: Grassroots Support in a Republican Primary Campaign
Authors: Djupe Paul A. , Neiheisel Jacob R.
Published: March 2008

Seizing upon the opportunity afforded by a Republican primary contest in which a candidate backed by the Christian Right took on a candidate with connections to the party establishment, we examine the strength of the Christian right at the grassroots in Ohio. Using individual-level data compiled from an original survey instrument administered to over 1,000 Republican primary voters just after the May, 2006 primary, we present a more comprehensive model of both Christian Right support and the effect of Christian Right support on the vote choice. Instead of assuming a grassroots presence underpinning the movement, we assert and test the argument that natural elements of the social structure inhibit effective group access to collections of supporters. In doing so, we provide an explanation for the often observed gulf between movement identifiers and opinion-based supporters.
When Church Teachings and Policy Commitments Collide: Perspectives on Catholics in the U.S. House of Representatives
Authors: Oldmixon Elizabeth A. , Hudson William
Published: March 2008

This article investigates the influence of religious values on domestic social policy-making, with a particular focus on Catholics. We analyze roll call votes in the 109thCongress and find that Catholic identification is associated with support for Catholic Social Teaching, but both younger Catholics and Republican Catholics are found less supportive. In followup interviews with a small sample of Catholic Republicans, we find that they justify voting contrary to Church teaching by seeing its application to most domestic social issues as less authoritative than Church moral teachings on issues like abortion.
The Ethical Use of Psychological Tests: Australia
Authors: Davidson Graham
Published: March 2008

Statements of ethics and related guidelines have been developed in Australia over the period since 1968, covering psychological testing in general, and practices of individual, group, ‘blind' and computerized testing in particular. Guidelines on the psychological testing of indigenous people of Australia also exist. Changes in regulatory statements and supplementary guidelines over this period reflect support for the following: the scientist-practitioner philosophy of psychological practice; multimethod approaches to psychological assessment; and the explication of ‘best practice' in testing. The concept of contextual competence, contained in the various guidelines, may be extended to include cultural competence. The statements and guidelines reflect the ethical precepts of fidelity, beneficence, nonmaleficence and justice, and are reinforced by recent policy statements on professional competencies and continuing professional development.
“The Whole is More than the Sum of its Parts”: The Effects of Grouping and Randomizing Items on the Reliability and Validity of Questionnaires
Authors: Franke Gabriele Helga
Published: March 2008

This investigation was concerned with the widely spread practice to extract subscales from extensive psychodiagnostic inventories and to present their items in questionnaires as homogeneous item-blocks. By way of examining the effects of the mode of item-presentation on the reliability and validity, the frequently used and validated SCL-90-R was analyzed as a prototype of multidimensional symptom self-report inventories. Two studies were conducted in different contexts of application (study I: controlled group testing, study II: non-controlled individual testing) and involved different groups of subjects (study I: 130 nursing school students, study II: 134 university students). In both studies the standard item-arrangement was contrasted with the item-block presentation, which groups together items measuring the same dimension. The results revealed significant effects of item-blocking on the mean values, on the reliability, and the validity of the questionnaire. The findings seriously call into question the admissibility of subscale-extraction for self-report inventories. We conclude that the Gestalt paradigm, “The whole is more than the sum of its parts,” is valid for multidimensional psychodiagnostic inventories.
A Psycholexical Route to Content Coverage in Personality Assessment
Authors: De Raad Boele , Hendriks A.A. Jolijn
Published: March 2008

The psycholexical approach to personality, which has resulted in a widely accepted framework of personality trait description, is used for the development of the construction of a personality questionnaire. The principles and theoretical notions leading to the Big Five trait model are discussed, and a brief description is given of the recently developed circumplex representation (AB5C) of the five factors. The AB5C trait representation is employed in an integrated approach with the central idea of the facet methodology, enabling an optimal coverage of the contents of the trait sphere. The resulting faceted presentation is used for the generation of items for a encompassing personality questionnaire. The procedure for item-production is described. A unique feature in the construction of the item-pool is the fact that the items are constructed in an interactive process between English-American, German, and Dutch teams. Coverage of the trait domain following the described procedure is tested by relating the results to the various niches of the AB5C system.
Three‐dimensional S velocity of the mantle in the Africa‐Eurasia plate boundary region from phase arrival times and regional waveforms
Authors: Schmid C. , van der Lee S. , VanDecar J. C. , Engdahl E. R. , Giardini D.
Published: March 2008

A new model of the three‐dimensional shear velocity structure of the Africa‐Eurasia plate boundary is presented. The new model is derived by jointly inverting different types of seismic data. The two main sources of information are regional waveforms and teleseismic S wave arrival times. We show that it is possible to find a model that fit the different data types nearly as well as when inverting solely one type of data. The main improvement in resolving power is achieved between depths of 300 and 700 km, though the improvements are not limited to this depth range. Our model reflects the complicated evolution of this plate boundary area. The transition zone is dominated by high‐velocity anomalies which we infer to represent a mix of lithosphere that subducted relatively recently or is not sufficiently cold and dense to traverse the 660‐km discontinuity. The only low‐velocity zone in the transition zone is beneath the Ionian Sea. The high‐velocity Hellenic slab is continuous throughout the upper mantle and into the lower mantle to about 1200 km, most likely representing subducted Neo‐Tethys lithosphere. The uppermost mantle is dominated by low velocities, consistent with the high level of tectonic activity. Low‐velocity regions are relatively strong beneath the Mid‐Atlantic Ridge, Turkey, and the Dead Sea region. The region's current lithosphere is relatively thin, except beneath the Adriatic and Ionian seas and the easternmost Atlantic Ocean.
Spatial interpolation of precipitation in a dense gauge network for monsoon storm events in the southwestern United States
Authors: Garcia Matthew , Peters‐Lidard Christa D. , Goodrich David C.
Published: March 2008

Inaccuracy in spatially distributed precipitation fields can contribute significantly to the uncertainty of hydrological states and fluxes estimated from land surface models. This paper examines the results of selected interpolation methods for both convective and mixed/stratiform events that occurred during the North American monsoon season over a dense gauge network at the U.S. Department of Agriculture Agricultural Research Service Walnut Gulch Experimental Watershed in the southwestern United States. The spatial coefficient of variation for the precipitation field is employed as an indicator of event morphology, and a gauge clustering factor CF is formulated as a new, scale‐independent measure of network organization. We consider that CF < 0 (a more distributed gauge network) will produce interpolation errors by reduced resolution of the precipitation field and that CF > 0 (clustering in the gauge network) will produce errors because of reduced areal representation of the precipitation field. Spatial interpolation is performed using both inverse‐distance‐weighted (IDW) and multiquadric‐biharmonic (MQB) methods. We employ ensembles of randomly selected network subsets for the statistical evaluation of interpolation errors in comparison with the observed precipitation. The magnitude of interpolation errors and differences in accuracy between interpolation methods depend on both the density and the geometrical organization of the gauge network. Generally, MQB methods outperform IDW methods in terms of interpolation accuracy under all conditions, but it is found that the order of the IDW method is important to the results and may, under some conditions, be just as accurate as the MQB method. In almost all results it is demonstrated that the inverse‐distance‐squared method for spatial interpolation, commonly employed in operational analyses and for engineering assessments, is inferior to the ID‐cubed method, which is also more computationally efficient than the MQB method in studies of large networks.
UV Io footprint leading spot: A key feature for understanding the UV Io footprint multiplicity?
Authors: Bonfond B. , Grodent D. , Gérard J.‐C. , Radioti A. , Saur J. , Jacobsen S.
Published: March 2008

The electromagnetic interaction between Io and the Jovian magnetosphere generates a UV auroral footprint in both Jovian hemispheres. Multiple spots were observed in the northern Jovian hemisphere when Io was in the northern part of the plasma torus and vice‐versa for the South. Based on recent Hubble Space Telescope (HST) measurements, we report here the discovery of a UV leading spot, i.e., a faint emission located ahead of the main spot. The leading spot emerges at System III longitudes between 0° and 100° in the northern hemisphere and between 130° and 300° in the southern hemisphere, i.e., in one hemisphere when multiple spots are observed in the other hemisphere. We propose as one potential mechanism that electron beams observed near Io are related to the generation of the leading spot and the secondary spot in the opposite hemisphere.
Longitudinal variations of electron temperature and total ion density in the sunset equatorial topside ionosphere
Authors: Ren Zhipeng , Wan Weixing , Liu Libo , Zhao Biqiang , Wei Yong , Yue Xinan , Heelis Roderick A.
Published: March 2008

Based on the DMSP F13 Satellite observations from 1995 to 2005, the longitudinal distributions of the electron temperature (Te) and total ion density (Ni) in the sunset equatorial topside ionosphere are examined. The results suggest that the longitudinal variations of both Te and Ni exhibit obvious seasonal dependence as follows: (1) wavenumber‐four longitudinal structure in equinox, (2) three peaks structure in June solstice, and (3) two peaks structure in December solstice. Moreover, the longitudinal variations of Te and Ni show significant anti‐correlation, and we speculate that the longitudinal variation of Te may result from that of Ni which can control Te through the electron cooling rate. The wavenumber‐four longitudinal structures of both Te and Ni in equinox may relate to the eastward propagating zonal wavenumber‐3 diurnal tide (DE3), which has effect on the amplitude of the daytime zonal electric field. The longitudinal variation of Te and Ni in the two solstices may be caused both by longitudinal variation of geomagnetic declination and DE3.
A quantitative MHD study of the relation among arcade shearing, flux rope formation, and eruption due to the tearing instability
Authors: Shiota D. , Kusano K. , Miyoshi T. , Nishikawa N. , Shibata K.
Published: March 2008

The quantitative relationship between the magnetohydrodynamic (MHD) activity of solar coronal arcade and the magnetic helicity injection, which is caused by shearing motion, has been investigated, using azimuthally symmetric model of MHD simulation. We have calculated several cases in which the width of the shearing region is varied and examined the relationship between the magnetic arcade dynamics and magnetic helicity evolution. As a result, it is found that as the shearing motion is imposed on narrower regions along each side of the magnetic inversion line, the magnetic arcade can be easily destabilized by the resistive tearing mode. However, in this case, even though reconnection driven by the tearing mode produces plasmoids, the plasmoid elevation is almost in proportion to the total amount of magnetic helicity contained in the arcade, and it is too slow to explain the trigger process of coronal mass ejections (CMEs). On the other hand, in the case where the shearing motion is imposed on the entire region, much larger magnetic helicity injection is required to injected arcade in order to destabilize the system, compared to practical helicity injection measured in the solar corona. The results suggest that it may be difficult to trigger a CME just by the axisymmetric shearing motion and that some other mechanisms should be involved in the triggering process of a CME. The results also imply that the relation between the magnetic helicity and the overlying magnetic flux can be a key parameter for the CME occurrence.
Source regions of solar wind disappearance events
Authors: Janardhan P. , Fujiki K. , Sawant H. S. , Kojima M. , Hakamada K. , Krishnan R.
Published: March 2008

During the period 1999–2002 there have been three instances, in May 1999, March 2002, and May 2002, respectively, when the solar wind densities at 1 AU dropped to abnormally low values (<0.1 cm−3) for extended periods of time (12–24 h). These long‐lasting low‐density anomalies observed at 1 AU are referred to as “solar wind disappearance events” and in this paper, we locate the solar sources of the two disappearance events in March and May 2002 and show that like the well‐studied disappearance event of 11 May 1999, these events too originate in active region complexes located at central meridian and are characterized by highly nonradial solar wind outflows. We also show that during disappearance events, the interplanetary magnetic field is stable and unipolar and the associated solar wind outflows have extended Alfvén radii. Using the fact that solar wind flows from active regions have higher ratios of O7+/O6+ than wind from coronal holes, we try to pinpoint the solar sources of these very unusual and rare events and show that they represent the dynamic evolution of either active region open fields or small coronal hole boundaries embedded in or near large active region complexes located at or close to central meridian.
Regional seismic observations of the 9 October 2006 underground nuclear explosion in North Korea and the influence of crustal structure on regional phases
Authors: Hong Tae‐Kyung , Baag Chang‐Eob , Choi Hoseon , Sheen Dong‐Hoon
Published: March 2008

The crustally guided shear wave, Lg, is typically the most prominent phase of a nuclear explosion at regional distance. This Lg phase is analyzed often to discriminate a nuclear explosion from a natural earthquake. In addition, the Lg phase allows us to determine the size of the detonation. A nuclear explosion test in North Korea was conducted on 9 October 2006. The epicenter was located close to the eastern shore of the Korean Peninsula, resulting in raypaths that vary significantly according to the azimuths. In particular, rays radiated in the southern direction experience lateral variation of crustal structures at the continental margin. We examine the influence of raypaths on regional seismic phases by comparing the spectra and waveforms from different raypaths. Three natural earthquakes in North Korea are also examined to determine the raypath effect. We find that the Lg from the nuclear explosion dissipated significantly as result of energy leakage into the mantle resulting from variations in crustal thickness along the portion of the raypath traversing the western tip of the Sea of Japan (East Sea). Some of the leaked energy develops into mantle lid waves (Sn), causing a large energy increase to Sn. A similar feature is observed in the records of natural earthquakes. This feature is confirmed by seismic waveform modeling. The raypath effect also causes underestimation of magnitude. The Lg body wave magnitude, mb(Lg), is estimated to be 3.8–4.2 for records from pure continental paths and 2.6–3.4 for records from paths crossing continental margins. This result illustrates the need to consider raypath effects for the correct estimation of magnitudes of regional events, including a nuclear explosion.
Seismic structure of the southern Gulf of California from Los Cabos block to the East Pacific Rise
Authors: Páramo P. , Holbrook W. S. , Brown H. E. , Lizarralde D. , Fletcher J. , Umhoefer P. , Kent G. , Harding A. , Gonzalez A. , Axen G.
Published: March 2008

Multichannel reflection and coincident wide‐angle seismic data collected during the 2002 Premier Experiment, Sea of Cortez, Addressing the Development of Oblique Rifting (PESCADOR) experiment provide the most detailed seismic structure to date of the southern Gulf of California. Multichannel seismic (MCS) data were recorded with a 6‐km‐long streamer, 480‐channel, aboard the R/V Maurice Ewing, and wide‐angle data was recorded by 19 instruments spaced every ∼12 km along the transect. The MCS and wide‐angle data reveal the seismic structure across the continent‐ocean transition of the rifted margin. Typical continental and oceanic crust are separated by a ∼75‐km‐wide zone of extended continental crust dominated by block‐faulted basement. Little lateral variation in crustal thicknesses and seismic velocities is observed in the oceanic crust, suggesting a constant rate of magmatic productivity since seafloor spreading began. Oceanic crustal thickness and mean crustal velocities suggest normal mantle temperature (1300°C) and passive mantle upwelling at the early stages of seafloor spreading. The crustal thickness, width of extended continental crust, and predicted temperature conditions all indicate a narrow rift mode of extension. On the basis of upper and lower crust stretching factors, an excess of lower crust was found in the extended continental crust. Total extension along transect 5W is estimated to be ∼35 km. Following crustal extension, new oceanic crust ∼6.4‐km‐thick was formed at a rate of ∼48 mm a−1 to accommodate plate separation.
An estimate of monthly global emissions of anthropogenic CO2: Impact on the seasonal cycle of atmospheric CO2
Authors: Erickson D. J. , Mills R. T. , Gregg J. , Blasing T. J. , Hoffman F. M. , Andres R. J. , Devries M. , Zhu Z. , Kawa S. R.
Published: March 2008

Monthly estimates of the global emissions of anthropogenic CO2 are presented. Approximating the seasonal CO2 emission cycle using a 2‐harmonic Fourier series with coefficients as a function of latitude, the annual fluxes are decomposed into monthly flux estimates based on data for the United States and applied globally. These monthly anthropogenic CO2 flux estimates are then used to model atmospheric CO2 concentrations using meteorological fields from the NASA GEOS‐4 data assimilation system. We find that the use of monthly resolved fluxes makes a significant difference in the seasonal cycle of atmospheric CO2 in and near those regions where anthropogenic CO2 is released to the atmosphere. Local variations of 2–6 ppmv CO2 in the seasonal cycle amplitude are simulated; larger variations would be expected if smaller source‐receptor distances could be more precisely specified using a more refined spatial resolution. We also find that in the midlatitudes near the sources, synoptic scale atmospheric circulations are important in the winter and that boundary layer venting and diurnal rectifier effects are more important in the summer. These findings have implications for inverse‐modeling efforts that attempt to estimate surface source/sink regions especially when the surface sinks are colocated with regions of strong anthropogenic CO2 emissions.
Ligand sensitivity in dimeric associations of the serotonin 5HT2c receptor
Authors: Mancia Filippo , Assur Zahra , Herman Ariel G , Siegel Risa , Hendrickson Wayne A
Published: March 2008

G‐protein‐coupled receptors (GPCRs) respond to external stimuli by activating heterotrimeric G proteins inside the cell. There is increasing evidence that many GPCRs exist as dimers or higher oligomers, but the biochemical nature of such dimers and what roles they have, if any, in signal transduction remains unclear. We conducted a comprehensive study of dimerization of the 5HT2c serotonin receptor using disulphide‐trapping experiments. We found a dimer interface between transmembrane (TM) helices IV and V that is markedly sensitive to the state of receptor activation. This dimer seems to be quasisymmetrical in interfacial geometry and asymmetrical in its association with its cognate Gα protein. We also found a second interface at TM I helices, which is insensitive to the state of activation.
Clathrin‐independent endocytosis used by the IL‐2 receptor is regulated by Rac1, Pak1 and Pak2
Authors: Grassart Alexandre , Dujeancourt Annick , Lazarow Paul B , Dautry‐Varsat Alice , Sauvonnet Nathalie
Published: March 2008

There are several endocytic pathways, which are either dependent on or independent of clathrin. This study focuses on a poorly characterized mechanism—clathrin‐ and caveolae‐independent endocytosis—used by the interleukin‐2 receptor β (IL‐2Rβ). We address the question of its regulation in comparison with the clathrin‐dependent pathway. First, we show that Ras‐related C3 botulinum toxin substrate 1 (Rac1) is specifically required for IL‐2Rβ entry, and we identify p21‐activated kinases (Paks) as downstream targets. By RNA interference, we show that Pak1 and Pak2 are both necessary for IL‐2Rβ uptake, in contrast to the clathrin‐dependent route. We observe that cortactin, a partner of actin and dynamin—two essential endocytic factors—is required for IL‐2Rβ uptake. Furthermore, we find that cortactin acts downstream from Paks, suggesting control of its function by these kinases. Thus, we describe a cascade composed of Rac1, Paks and cortactin specifically regulating IL‐2Rβ internalization. This study indicates Paks as the first specific regulators of the clathrin‐independent endocytosis pathway.
Overexpression of cold‐inducible RNA‐binding protein increases interferon‐γ production in Chinese‐hamster ovary cells
Authors: Tan Hong Kiat , Lee May May , Yap Miranda G. S. , Wang Daniel I. C.
Published: March 2008

Culturing recombinant CHO (Chinese‐hamster ovary) cells at low temperatures (30–33 °C) increases specific recombinant protein productivity by 2–5‐fold. However, even though the specific productivity is increased, cell growth is decreased in low‐temperature culture such that the final recombinant protein titre remains unchanged or is even diminished, owing to the lower cell density. Exposing mammalian cells to low temperatures results in a change in the expression of many ‘cold‐stress’ genes. CIRP (cold‐inducible RNA‐binding protein) is a cold‐stress protein that is highly expressed at 32 °C, but not at 37 °C. In the present study we demonstrated that overexpression of CIRP at 37 °C can increase the recombinant‐protein titre in CHO cells. Stable overexpression of CIRP at 37 °C improved the final titre of CHO IFN‐γ, a recombinant CHO cell line producing human IFN‐γ (interferon‐γ), by 25% in adherent culture and up to 40% in suspension culture. Real‐time PCR analysis showed that the increase in the recombinant IFN‐γ titre could be attributed to increased recombinant IFN‐γ mRNA levels, while growth data showed that CIRP overexpression did not result in growth arrest in CHO IFN‐γ cells. Glycan analysis showed that the increase in IFN‐γ titre as a result of CIRP overexpression did not affect the site occupancy, glycan structures or sialic acid content of IFN‐γ. Using this strategy, the final IFN‐γ titre was increased by 40% compared with current temperature‐based strategies. Furthermore, there is no decrease in cell growth or recombinant‐protein glycosylation quality, as previously observed in low‐temperature culture.
Using computational fluid dynamics to characterize and improve bioreactor performance
Authors: Kelly William J.
Published: March 2008

CFD (computational fluid dynamics) has been used to model upstream bioprocessing steps such as fermentation and homogenization. The focus of these studies has oftentimes been to characterize single‐phase (liquid) flow and hydrodynamic shear. In the actual bioprocessing operations, however, there are at least two phases (cells and liquid) present. In the bioreactor, the gas bubbles constitute a third phase. More recent CFD models have considered the momentum and mass transfer that occurs between the phases. This review summarizes studies from the biochemical and biomedical literature relating to the use of CFD to model the performance of a variety of bioreactor types. Particular emphasis will be placed on describing current methods for handling multi‐phase flow involving animal cells and/or gas bubbles.
n-Propyl gallate activates hypoxia-inducible factor 1 by modulating intracellular oxygen-sensing systems
Authors: Kimura Motohide , Takabuchi Satoshi , Tanaka Tomoharu , Murata Miyahiko , Nishi Kenichiro , Oda Seiko , Oda Tomoyuki , Kanai Michiyuki , Fukuda Kazuhiko , Kizaka-Kondoh Shinae , Adachi Takehiko , Takabayashi Arimichi , Semenza Gregg L. , Hirota Kiichi
Published: March 2008

HIF-1 (hypoxia-inducible factor 1) is a master regulator of cellular adaptive responses to hypoxia. The expression and transcriptional activity of the HIF-1α subunit is stringently controlled by intracellular oxygen tension through the action of prolyl and asparaginyl hydroxylases. In the present study we demonstrate that PG (n-propyl gallate) activates HIF-1 and expression of its downstream target genes under normoxic conditions in cultured cells and in mice. The stability and transcriptional activity of HIF-1α are increased by PG. PG treatment inhibits the interaction between HIF-1α and VHL (von Hippel–Lindau protein) and promotes the interaction between HIF-1α and p300, indicating that PG inhibits the activity of both prolyl and asparaginyl HIF-1α hydroxylases. We conclude that PG activates HIF-1 and enhances the resultant gene expression by directly affecting the intracellular oxygen sensing system in vitro and in vivo and that PG represents a lead compound for the development of a non-toxic activator of HIF-1.
A role for PFK-2/FBPase-2, as distinct from fructose 2,6-bisphosphate, in regulation of insulin secretion in pancreatic β-cells
Authors: Arden Catherine , Hampson Laura J. , Huang Guo C. , Shaw James A. M. , Aldibbiat Ali , Holliman Graham , Manas Derek , Khan Salmaan , Lange Alex J. , Agius Loranne
Published: March 2008

PFK-2/FBPase-2 (6-phosphofructo-2-kinase/fructose 2,6-bisphosphatase) catalyses the formation and degradation of fructose 2,6-P2 (fructose 2,6-bisphosphate) and is also a glucokinase-binding protein. The role of fructose 2,6-P2 in regulating glucose metabolism and insulin secretion in pancreatic β-cells is unresolved. We down-regulated the endogenous isoforms of PFK-2/FBPase-2 with siRNA (small interfering RNA) and expressed KA (kinase active) and KD (kinase deficient) variants to distinguish between the role of PFK-2/FBPase-2 protein and the role of its product, fructose 2,6-P2, in regulating β-cell function. Human islets expressed the PFKFB2 (the gene encoding isoform 2 of the PFK2/FBPase2 protein) and PFKFB3 (the gene encoding isoform 3 of the PFK2/FBPase2 protein) isoforms and mouse islets expressed PFKFB2 at the mRNA level [RT–PCR (reverse transcription–PCR)]. Rat islets expressed PFKFB2 lacking the C-terminal phosphorylation sites. The glucose-responsive MIN6 and INS1E cell lines expressed PFKFB2 and PFKFB3. PFK-2 activity and the cell content of fructose 2,6-P2 were increased by elevated glucose concentration and during pharmacological activation of AMPK (AMP-activated protein kinase), which also increased insulin secretion. Partial down-regulation of endogenous PFKFB2 and PFKFB3 in INS1E by siRNA decreased PFK-2/FBPase-2 protein, fructose 2,6-P2 content, glucokinase activity and glucoseinduced insulin secretion. Selective down-regulation of glucose-induced fructose 2,6-P2 in the absence of down-regulation of PFK-2/FBPase-2 protein, using a KD PFK-2/FBPase-2 variant, resulted in sustained glycolysis and elevated glucose-induced insulin secretion, indicating an over-riding role of PFK-2/FBPase-2 protein, as distinct from its product fructose 2,6-P2, in potentiating glucose-induced insulin secretion. Whereas down-regulation of PFK-2/FBPase-2 decreased glucokinase activity, overexpression of PFK-2/FBPase-2 only affected glucokinase distribution. It is concluded that PFK-2/FBPase-2 protein rather than its product fructose 2,6-P2 is the over-riding determinant of glucose-induced insulin secretion through regulation of glucokinase activity or subcellular targeting.
The binding of PRAS40 to 14-3-3 proteins is not required for activation of mTORC1 signalling by phorbol esters/ERK
Authors: Fonseca Bruno D. , Lee Vivian H.-Y. , Proud Christopher G.
Published: March 2008

PRAS40 binds to the mTORC1 (mammalian target of rapamycin complex 1) and is released in response to insulin. It has been suggested that this effect is due to 14-3-3 binding and leads to activation of mTORC1 signalling. In a similar manner to insulin, phorbol esters also activate mTORC1 signalling, in this case via PKC (protein kinase C) and ERK (extracellular-signal-regulated kinase). However, phorbol esters do not induce phosphorylation of PRAS40 at Thr246, binding of 14-3-3 proteins to PRAS40 or its release from mTORC1. Mutation of Thr246 to a serine residue permits phorbol esters to induce phosphorylation and binding to 14-3-3 proteins. Such phosphorylation is apparently mediated by RSKs (ribosomal S6 kinases), which lie downstream of ERK. However, although the PRAS40(T246S) mutant binds to 14-3-3 better than wild-type PRAS40, each inhibits mTORC1 signalling to a similar extent. Our results show that activation of mTORC1 signalling by phorbol esters does not require PRAS40 to be phosphorylated at Thr246, bind to 14-3-3 or be released from mTORC1. It is conceivable that phorbol esters activate mTORC1 by a distinct mechanism not involving PRAS40. Indeed, our results suggest that PRAS40 may not actually be involved in controlling mTORC1, but rather be a downstream target of mTORC1 that is regulated in response only to specific stimuli, such as insulin.
Post-translational modification and proteolytic processing of urinary osteopontin
Authors: Christensen Brian , Petersen Torben E. , Sørensen Esben S.
Published: March 2008

OPN (osteopontin) is a highly phosphorylated glycoprotein present in many tissues and body fluids. In urine, OPN is a potent inhibitor of nucleation, growth and aggregation of calcium oxalate crystals, suggesting that it has a role in the prevention of renal stone formation. The role of OPN in nephrolithiasis is, however, somewhat unclear, as it may also be involved in urinary stone formation, and it has been identified among the major protein components of renal calculi. Most likely, the function of OPN in urine is dependent on the highly anionic character of the protein. Besides a very high content of aspartic and glutamic residues, OPN is subjected to significant PTM (post-translational modification), such as phosphorylation, sulfation and glycosylation, which may function as regulatory switches in promotion or inhibition of mineralization. In the present study, we have characterized the PTMs of intact human urinary OPN and N-terminal fragments thereof. MS analysis showed a mass of 37.7 kDa for the intact protein. Enzymatic dephosphorylation and peptide mass analyses demonstrated that the protein contains approximately eight phosphate groups distributed over 30 potential phosphorylation sites. In addition, one sulfated tyrosine and five O-linked glycosylations were identified in OPN, whereas no N-linked glycans were detected. Peptide mapping and immunoblotting using different monoclonal antibodies showed that the N-terminal fragments present in urine are generated by proteolytic cleavage at Arg228–Leu229 and Tyr230–Lys231.
Effect of lysosomal storage on bis(monoacylglycero)phosphate
Authors: Meikle Peter J. , Duplock Stephen , Blacklock David , Whitfield Phillip D. , Macintosh Gemma , Hopwood John J. , Fuller Maria
Published: March 2008

BMP [bis(monoacylglycero)phosphate] is an acidic phospholipid and a structural isomer of PG (phosphatidylglycerol), consisting of lysophosphatidylglycerol with an additional fatty acid esterified to the glycerol head group. It is thought to be synthesized from PG in the endosomal/lysosomal compartment and is found primarily in multivesicular bodies within the same compartment. In the present study, we investigated the effect of lysosomal storage on BMP in cultured fibroblasts from patients with eight different LSDs (lysosomal storage disorders) and plasma samples from patients with one of 20 LSDs. Using ESI-MS/MS (electrospray ionization tandem MS), we were able to demonstrate either elevations or alterations in the individual species of BMP, but not of PG, in cultured fibroblasts. All affected cell lines, with the exception of Fabry disease, showed a loss of polyunsaturated BMP species relative to mono-unsaturated species, and this correlated with the literature reports of lysosomal dysfunction leading to elevations of glycosphingolipids and cholesterol in affected cells, processes thought to be critical to the pathogenesis of LSDs. Plasma samples from patients with LSDs involving storage in macrophages and/or with hepatomegaly showed an elevation in the plasma concentration of the C18:1/C18:1 species of BMP when compared with control plasmas, whereas disorders involving primarily the central nervous system pathology did not. These results suggest that the release of BMP is cell/tissue-specific and that it may be useful as a biomarker for a subset of LSDs.
Brm transactivates the telomerase reverse transcriptase (TERT) gene and modulates the splicing patterns of its transcripts in concert with p54nrb
Authors: Ito Taiji , Watanabe Hirotaka , Yamamichi Nobutake , Kondo Shunsuke , Tando Toshio , Haraguchi Takeshi , Mizutani Taketoshi , Sakurai Kouhei , Fujita Shuji , Izumi Tomonori , Isobe Toshiaki , Iba Hideo
Published: March 2008

We report that a DBHS (Drosophila behaviour, human splicing) family protein, p54nrb, binds both BRG1 (Brahma-related gene 1) and Brm (Brahma), catalytic subunits of the SWI/SNF (switch/sucrose non-fermentable) chromatin remodelling complex, and also another core subunit of this complex, BAF60a. The N-terminal region of p54nrb is sufficient to pull-down other core subunits of the SWI/SNF complex, suggesting that p54nrb binds SWI/SNF-like complexes. PSF (polypyrimidine tract-binding protein-associated splicing factor), another DBHS family protein known to directly bind p54nrb, was also found to associate with the SWI/SNF-like complex. When sh (short hairpin) RNAs targeting Brm were retrovirally expressed in a BRG1-deficient human cell line (NCI-H1299), the resulting clones showed down-regulation of the TERT (telomerase reverse transcriptase) gene and an enhancement of ratios of exon-7-and-8-excluded TERT mRNA that encodes a β-site-deleted inactive protein. All of these clones display growth arrest within 2 months of the Brm-knockdown. In NCI-H1299 cells, Brm, p54nrb, PSF and RNA polymerase II phosphorylated on CTD (C-terminal domain) Ser2 specifically co-localize at a region incorporating an alternative splicing acceptor site of TERT exon 7. These findings suggest that, at the TERT gene locus in human tumour cells containing a functional SWI/SNF complex, Brm, and possibly BRG1, in concert with p54nrb, would initiate efficient transcription and could be involved in the subsequent splicing of TERT transcripts by accelerating exon-inclusion, which partly contributes to the maintenance of active telomerase.
A Ca2+-dependent bacterial antifreeze protein domain has a novel β-helical ice-binding fold
Authors: Garnham Christopher P. , Gilbert Jack A. , Hartman Christopher P. , Campbell Robert L. , Laybourn-Parry Johanna , Davies Peter L.
Published: March 2008

AFPs (antifreeze proteins) are produced by many organisms that inhabit ice-laden environments. They facilitate survival at sub-zero temperatures by binding to, and inhibiting, the growth of ice crystals in solution. The Antarctic bacterium Marinomonas primoryensis produces an exceptionally large (>1 MDa) hyperactive Ca2+-dependent AFP. We have cloned, expressed and characterized a 322-amino-acid region of the protein where the antifreeze activity is localized that shows similarity to the RTX (repeats-in-toxin) family of proteins. The recombinant protein requires Ca2+ for structure and activity, and it is capable of depressing the freezing point of a solution in excess of 2 °C at a concentration of 0.5 mg/ml, therefore classifying it as a hyperactive AFP. We have developed a homology-guided model of the antifreeze region based partly on the Ca2+-bound β-roll from alkaline protease. The model has identified both a novel β-helical fold and an ice-binding site. The interior of the β-helix contains a single row of bound Ca2+ ions down one side of the structure and a hydrophobic core down the opposite side. The ice-binding surface consists of parallel repetitive arrays of threonine and aspartic acid/asparagine residues located down the Ca2+-bound side of the structure. The model was tested and validated by site-directed mutagenesis. It explains the Ca2+-dependency of the region, as well its hyperactive antifreeze activity. This is the first bacterial AFP to be structurally characterized and is one of only five hyperactive AFPs identified to date.
Hepcidin expression in mouse retina and its regulation via lipopolysaccharide/Toll-like receptor-4 pathway independent of Hfe
Authors: Gnana-Prakasam Jaya P. , Martin Pamela M. , Mysona Barbara A. , Roon Penny , Smith Sylvia B. , Ganapathy Vadivel
Published: March 2008

Hepcidin is a hormone central to the regulation of iron homeostasis in the body. It is believed to be produced exclusively by the liver. Ferroportin, an iron exporter, is the receptor for hepcidin. This transporter/receptor is expressed in Müller cells, photoreceptor cells and the RPE (retinal pigment epithelium) within the retina. Since the retina is protected by the retinal–blood barriers, we asked whether ferroportin in the retina is regulated by hepcidin in the circulation or whether the retina produces hepcidin for regulation of its own iron homeostasis. Here we show that hepcidin is expressed robustly in Müller cells, photoreceptor cells and RPE cells, closely resembling the expression pattern of ferroportin. We also show that bacterial LPS (lipopolysaccharide) is a regulator of hepcidin expression in Müller cells and the RPE, both in vitro and in vivo, and that the regulation occurs at the transcriptional level. The action of LPS on hepcidin expression is mediated by the TLR4 (Toll-like receptor-4). The upregulation of hepcidin by LPS occurs independent of Hfe (human leukocyte antigen-like protein involved in Fe homeostasis). The increase in hepcidin levels in retinal cells in response to LPS treatment is associated with a decrease in ferroportin levels. The LPS-induced upregulation of hepcidin and consequent down-regulation of ferroportin is associated with increased oxidative stress and apoptosis within the retina in vivo. We conclude that retinal iron homeostasis may be regulated in an autonomous manner by hepcidin generated within the retina and that chronic bacterial infection/inflammation of the retina may disrupt iron homeostasis and retinal function.
The functional relationship between co-repressor N-CoR and SMRT in mediating transcriptional repression by thyroid hormone receptor α
Authors: Choi Kyung-Chul , Oh So-Young , Kang Hee-Bum , Lee Yoo-Hyun , Haam Seungjoo , Kim Ha-Il , Kim Kunhong , Ahn Young-Ho , Kim Kyung-Sup , Yoon Ho-Geun
Published: March 2008

A central issue in mediating repression by nuclear hormone receptors is the distinct or redundant function between co-repressors N-CoR (nuclear receptor co-repressor) and SMRT (silencing mediator of retinoid and thyroid hormone receptor). To address the functional relationship between SMRT and N-CoR in TR (thyroid hormone receptor)-mediated repression, we have identified multiple TR target genes, including BCL3 (B-cell lymphoma 3-encoded protein), Spot14 (thyroid hormone-inducible hepatic protein), FAS (fatty acid synthase), and ADRB2 (β-adrenergic receptor 2). We demonstrated that siRNA (small interfering RNA) treatment against either N-CoR or SMRT is sufficient for the de-repression of multiple TR target genes. By the combination of sequence mining and physical association as determined by ChIP (chromatin immunoprecipitation) assays, we mapped the putative TREs (thyroid hormone response elements) in BCL3, Spot14, FAS and ADRB2 genes. Our data clearly show that SMRT and N-CoR are independently recruited to various TR target genes. We also present evidence that overexpression of N-CoR can restore repression of endogenous genes after knocking down SMRT. Finally, unliganded, co-repressor-free TR is defective in repression and interacts with a co-activator, p300. Collectively, these results suggest that both SMRT and N-CoR are limited in cells and that knocking down either of them results in co-repressor-free TR and consequently de-repression of TR target genes.
The 7-amino-acid site in the proline-rich region of the N-terminal domain of p53 is involved in the interaction with FAK and is critical for p53 functioning
Authors: Golubovskaya Vita M. , Finch Richard , Zheng Min , Kurenova Elena V. , Cance William G.
Published: March 2008

It is known that p53 alterations are commonly found in tumour cells. Another marker of tumorigenesis is FAK (focal adhesion kinase), a non-receptor kinase that is overexpressed in many types of tumours. Previously we determined that the N-terminal domain of FAK physically interacted with the N-terminal domain of p53. In the present study, using phage display, site-directed mutagenesis, pulldown and immunoprecipitation assays we localized the site of FAK binding to a 7-amino-acid region (amino acids 65–71) in the N-terminal proline-rich domain of human p53. Mutation of the binding site in p53 reversed the suppressive effect of FAK on p53-mediated transactivation of p21, BAX (Bcl-2-associated X protein) and Mdm2 (murine double minute 2) promoters. In addition, to functionally test this p53 site, we conjugated p53 peptides [wild-type (containing the wild-type binding site) and mutant (with a mutated 7-amino-acid binding site)] to a TAT peptide sequence to penetrate the cells, and demonstrated that the wild-type p53 peptide disrupted binding of FAK and p53 proteins and significantly inhibited cell viability of HCT116 p53+/+ cells compared with the control mutant peptide and HCT116 p53−/− cells. Furthermore, the TAT–p53 peptide decreased the viability of MCF-7 cells, whereas the mutant peptide did not cause this effect. Normal fibroblast p53+/+ and p53−/− MEF (murine embryonic fibroblast) cells and breast MCF10A cells were not sensitive to p53 peptide. Thus, for the first time, we have identified the binding site of the p53 and FAK interaction and have demonstrated that mutating this site and targeting the site with peptides affects p53 functioning and viability in the cells.
Fasting in healthy subjects is associated with intrahepatic accumulation of lipids as assessed by 1H-magnetic resonance spectroscopy
Authors: Moller Louise , Stodkilde-Jorgensen Hans , Jensen Finn T. , Jorgensen Jens O. L.
Published: March 2008

The impact of fasting on IHL (intrahepatic lipid) content in human subjects has not been investigated previously, but results indicate that it may change rapidly in response to metabolic cues. The aim of the present study was to measure IHL content after fasting and to correlate this with circulating lipid intermediates. A total of eight healthy non-obese young males were studied before and after 12 or 36 h of fasting. IHL content was assessed by 1H-magnetic resonance spectroscopy, and blood samples were drawn after the fasting period. IHL content increased significantly after the 36 h fasting period [median increase 156% (range, 4–252%); P<0.05]. Furthermore, a significant positive correlation between this increase and 3-hydroxybutyrate concentration was detected (P=0.03). No significant change in IHL content was demonstrated after the 12 h fasting period. The baseline median inter-individual variation in IHLs was 0.51% (range, 0.25–0.72%). The coefficient of variation of IHL measurements was 11.6%; 25–30% of the variation was of analytical origin and the remaining 70–75% was attributed to repositioning. In conclusion, IHL content increases in healthy male subjects during fasting, which demonstrates that nutritional status should be accounted for when assessing IHLs in clinical studies. Moreover, the increase in IHLs was positively correlated with the concentration of 3-hydroxybutyrate.
Role ofChlamydia pneumoniaein atherosclerosis
Authors: Watson Caroline , Alp Nicholas J.
Published: March 2008

Cardiovascular disease, resulting from atherosclerosis, is a leading cause of global morbidity and mortality. Genetic predisposition and classical environmental risk factors explain much of the attributable risk for cardiovascular events in populations, but other risk factors for the development and progression of atherosclerosis, which can be identified and modified, may be important therapeutic targets. Infectious agents, such as Chlamydia pneumoniae, have been proposed as contributory factors in the pathogenesis of atherosclerosis. In the present review, we consider the experimental evidence that has accumulated over the last 20 years evaluating the role of C. pneumoniae in atherosclerosis and suggest areas for future research in this field.