bluuebunny/crossref_metadata_2025 huggingface dataset:
Preference-Formation and Personal Good
Authors: Rosati Connie
Published: August 2006

As persons, beings with a capacity for autonomy, we face a certain practical task in living out our lives. At any given period we find ourselves with many desires or preferences, yet we have limited resources, and so we cannot satisfy them all. Our limited resources include insufficient economic means, of course; few of us have either the funds or the material provisions to obtain or pursue all that we might like. More significantly, though, we are limited to a single life and one of finite duration. We also age, and pursuits that were possible at earlier points within a life may become impossible at later stages; we thus encounter not only an ultimate time limit but episodic limits as well. Because we must live our lives with limited resources—material and temporal—we are pressed to choose among and to order our preferences. Without some selection and ordering, few if any of them would be satisfied, and we would be unable to live lives that are recognizably good at all. Moreover, we would be unable to function well as the autonomous beings that we are. Our practical task then is to form a coherent, stable, and attractive ordering of aims—to develop a conception of our good.
Content-Related and Attitude-Related Reasons for Preferences
Authors: Piller Christian
Published: August 2006

In the first section of this paper I draw, on a purely conceptual level, a distinction between two kinds of reasons: content-related and attitude-related reasons. The established view is that, in the case of the attitude of believing something, there are no attitude-related reasons. I look at some arguments intended to establish this claim in the second section with an eye to whether these argument could be generalized to cover the case of preferences as well. In the third section I argue against such generalizations and present a case in favour of accepting attitude-related reasons for preferences. In the fourth section I present an objection to which I react in the fifth section where I try to strengthen my case for attitude-related reasons for preferences. Finally, I discuss and reject criticisms raised by two opponents of the view defended here.
Preferences, Paternalism, and Liberty
Authors: Sunstein Cass
Published: August 2006

Our goal in this chapter is to draw on empirical work about preference formation and welfare to propose a distinctive form of paternalism, libertarian in spirit, one that should be acceptable to those who are firmly committed to freedom of choice on grounds of either autonomy or welfare. Indeed, we urge that a kind of ‘libertarian paternalism’ provides a basis for both understanding and rethinking many social practices, including those that deal with worker welfare, consumer protection, and the family.
Mapping of an ophiolite complex by high‐resolution visible‐infrared spectrometry
Authors: Combe Jean‐Philippe , Launeau Patrick , Pinet Patrick , Despan Daniela , Harris Esther , Ceuleneer Georges , Sotin Christophe
Published: August 2006

The Sumail massif of the Oman peridotite has been surveyed by the high spectral resolution imager HyMap. The field measurements have been taken simultaneously to the HyMap campaign with a GER 3700 spectrometer. To compare the two data sets, further calibration and atmospheric correction are made through empirical line corrections. A continuum removal by a modified Gaussian model on reflectance is then performed for each pixel to minimize atmospheric scattering and shadowing effects. Classification from spectral distance is established using field observations and comparisons at full spectral resolution to identify peridotite subunits (harzburgites and dunites) and to distinguish plagioclase‐wehrlites from gabbros. Detections of hydrothermal transformations of olivine in serpentines and their alteration in carbonates along fracture networks, characterized by narrow spectral signatures, validate the classification. This demonstrates the utility of the high spectral resolution and the development of appropriate processing methods for geological identifications.
Return period of nonlinear high wave crests
Authors: Arena Felice , Pavone Diego
Published: August 2006

This paper deals with the long‐term statistics for extreme nonlinear crest heights. First, a new analytical solution for the return period R(η), of a sea storm in which the maximum nonlinear crest height exceeds a fixed threshold η, is obtained by applying the ‘Equivalent Triangular Storm’ model and a second‐order crest height distribution. The probability P(ηc max > η∣[0, L]) that maximum nonlinear crest height in the time span L exceeds a fixed threshold is then derived from R(η) solution, assuming that the occurrence of storms with highest crest larger than η is given by a Poisson process. In the applications, both R(η) and P(ηc max > η∣[0, L]) are calculated for some locations. It is shown that narrowband second‐order approach is slightly conservative, with respect to the more general condition of crest distribution for second‐order three‐dimensional waves. Finally, a comparison with Boccotti, Jasper and Krogstad models is presented.
Climatic effects of different aerosol types in China simulated by the UCLA general circulation model
Authors: Gu Y. , Liou K. N. , Xue Y. , Mechoso C. R. , Li W. , Luo Y.
Published: August 2006

The climatic effects of various types of aerosol in China have been investigated by using the atmospheric general circulation model (AGCM) developed at the University of California, Los Angeles (UCLA). The model includes an efficient and physically based radiation parameterization scheme specifically developed for application to clouds and aerosols. Simulation results show that inclusion of a background aerosol optical depth of 0.2 reduces the global mean net surface solar flux by about 5 W m−2and produces a decrease in precipitation in the tropics as a result of decreased temperature contrast between this area and the middle to high latitudes, which suppresses tropical convection. These decreases have partially corrected the overestimates in the surface solar flux and precipitation in the UCLA AGCM simulations without the aerosol effect. The experiment with increased aerosol optical depths in China shows a noticeable increase in precipitation in the southern part of China in July due to the cooling in the midlatitudes that leads to the strengthening of the Hadley circulation. Aerosol types play an important role in the determination of the global mean radiation budget and regional climate. While sulfates mainly reflect solar radiation and induce negative forcing at the surface, black carbon and large dust particles absorb substantial solar radiation and have a positive solar forcing at the top of the atmosphere, but reduce the solar radiation reaching the surface. Large dust particles also have a significant effect on thermal IR radiation under clear conditions, but this effect is largely masked by clouds generated from the model in AGCM simulations. Black carbon and large dust particles in China would heat the air column in the middle to high latitudes and tend to move the simulated precipitation inland, i.e., toward the Himalayas. The inclusion of black carbon in our simulations has not produced the “north drought/south flooding” precipitation pattern that has frequently occurred in China during the past 50 years.
A neural network model for the separation of atmospheric effects on attenuation: Application to frequency scaling
Authors: Barthes Laurent , Mallet Cécile , Brisseau Olivier
Published: August 2006

Attenuation due to the propagation of radio waves through the Earth's atmosphere plays a major role in satellite link attenuation at frequencies beyond 20 GHz. This paper presents the development of an artificial neural network (ANN) to separate out the respective roles played by the three types of contributor, namely, gases (oxygen and water vapor), clouds, and rain, to the overall attenuation of radio waves. Whereas the inputs to the ANN are the total attenuation measured at either one, two, or three frequencies, the ANN outputs provide the three atmospheric attenuation components at a single frequency. Several neural networks were trained by using a simulated statistically significant data set, derived from absorption and diffusion models applied to atmospheric profiles. Good overall performance was observed, and a particularly good fit was achieved in the case where attenuation inputs were provided at two frequencies. From the estimated values of atmospheric attenuation for the three contributors, corresponding frequency scaling models were applied on each to estimate the three contributions at a new frequency. Total atmospheric attenuation at this new frequency can then be estimated. The method works using measured data at either one, two, or three frequencies and allows the total attenuation to be predicted at any other frequency in the range 20–50 GHz. Validation was successfully performed on real data.
Adenosine‐evoked Na+transport in human airway epithelial cells
Authors: Chambers L A , Constable M , Clunes M T , Olver R E , Ko W H , Inglis S K , Wilson S M
Published: August 2006

Background and purpose:

Absorptive epithelia express apical receptors that allow nucleotides to inhibit Na+transport but ATP unexpectedly stimulated this process in an absorptive cell line derived from human bronchiolar epithelium (H441 cells) whilst UTP consistently caused inhibition. We have therefore examined the pharmacological basis of this anomalous effect of ATP.

Experimental approach:

H441 cells were grown on membranes and the short circuit current (ISC) measured in Ussing chambers. In some experiments, [Ca2+]iwas measured fluorimetrically using Fura ‐2. mRNAs for adenosine receptors were determined by the polymerase chain reaction (PCR).

Key results:

Cross desensitization experiments showed that the inhibitory response to UTP was abolished by prior exposure to ATP whilst the stimulatory response to ATP persisted in UTP‐pre‐stimulated cells. Apical adenosine evoked an increase inISCand this response resembled the stimulatory component of the response to ATP, and could be mimicked by adenosine receptor agonists. Pre‐stimulation with adenosine abolished the stimulatory component of the response to ATP. mRNA encoding A1, A2Aand A2Breceptor subtypes, but not the A3subtype, was detected in H441 cells and adenosine receptor antagonists could abolish the ATP‐evoked stimulation of Na+absorption.

Conclusions and implications:

The ATP‐induced stimulation of Na+absorption seems to be mediated via A2A/Breceptors activated by adenosine produced from the extracellular hydrolysis of ATP. The present data thus provide the first description of adenosine‐evoked Na+transport in airway epithelial cells and reveal a previously undocumented aspect of the control of this physiologically important ion transport process.

British Journal of Pharmacology(2006)149, 43–55. doi:10.1038/sj.bjp.0706822
Matrix metalloproteinases contribute to endotoxin and interleukin‐1β induced vascular dysfunction
Authors: Lalu M M , Cena J , Chowdhury R , Lam A , Schulz R
Published: August 2006

Background and purpose:

The acute vascular inflammatory dysfunction associated with endotoxaemia may reflect an imbalance between matrix metalloproteinases (MMPs) and their natural inhibitors (TIMPs), induced by the endotoxin. This possibility was tested in rat aortic tissue.

Experimental approaches:

Tone induced by phenylephrine in aortic rings was measured after exposure in vitro to ambient lipopolysaccharide (LPS) or the proinflammatory cytokine interleukin‐1β (IL‐1β) for 6h, with or without MMP inhibitors (doxycycline or GM6001). Gelatinase and MMP activities, TIMP proteins and contractility were measured in aortae taken from rats 6h after receiving LPS in vivo.

Key results:

Inhibition of MMP prevented the loss of phenylephrine–induced tone in aortic rings after LPS or IL‐1β. IL‐1β also increased release of MMP‐2 activity from aortic tissue. In aortae exposed in vivo to LPS, net gelatinase, MMP‐9 activities and TIMP‐1 protein levels were increased, whereas TIMP‐4 was reduced. These aortae were hypocontractile to both phenylephrine and KCl. Hypocontractility was partially reversed by doxycycline ex vivo.

Conclusions and Implications:

MMP inhibitors ameliorate vascular hyporeactivity induced by either LPS or IL‐1β in vitro. LPS in vivo alters the balance between MMPs and TIMPs, contributing to vascular dysfunction which is partially reversed by MMP inhibitors. Vascular MMPs are activated as a result of LPS or IL‐1β‐induced stress and contribute to the hyporeactivity of blood vessels to vasoconstrictors.

British Journal of Pharmacology (2006) 149, 31–42. doi:10.1038/sj.bjp.0706823
Investigation of the prostacyclin (IP) receptor antagonist RO1138452 on isolated blood vessel and platelet preparations
Authors: Jones R L , Wise H , Clark R , Whiting R L , Bley K R
Published: August 2006

Background and purpose:

The current study examined the utility of the recently described prostacyclin (prostanoid IP) receptor antagonist RO1138452 (2‐(4‐(4‐isopropoxybenzyl)‐phenylamino) imidazoline) as a tool for classifying prostanoid receptors.

Experimental approach:

pA2 values were determined on isolated smooth muscle and platelet preparations.

Key results:

RO1138452 antagonized relaxation of human pulmonary artery, guinea‐pig aorta and rabbit mesenteric artery induced by the selective IP agonist cicaprost. Schild plots had slopes close to unity, generating pA2 values of 8.20, 8.39 and 8.12 respectively. Non‐surmountable antagonism was sometimes found with the higher concentrations of RO1138452, attributable to the EP3 contractile action of cicaprost. RO1138452 did not block relaxation of guinea‐pig trachea induced by the EP2‐selective agonist butaprost. In contrast, there was a modest inhibition of butaprost‐induced relaxation of human pulmonary artery by RO1138452, implying activation of both EP2 and IP receptors by butaprost. RO1138452 did not affect relaxation induced by PGE2 (EP4 agonist) and substance P (NK1/endothelium‐dependent agonist) in rabbit mesenteric artery. In human and rat platelet‐rich plasmas, RO1138452 antagonized cicaprost‐induced inhibition of platelet aggregation in a surmountable manner; pA2 values may have been affected by binding of RO1138452 to plasma protein. RO1138452 did not affect the inhibitory actions of PGD2 (DP1 agonist) and NECA (adenosine A2A agonist) in human platelets.

Conclusions and implications:

The data indicate that RO1138452 is a potent and selective IP receptor antagonist. RO1138452 represents an important addition to our armoury of prostanoid receptor antagonists and a potential clinical agent in situations where prostacyclin has a pathophysiological function.

British Journal of Pharmacology (2006) 149, 110–120. doi:10.1038/sj.bjp.0706841
The versatile nature of the calcium‐permeable cation channel TRPP2
Authors: Giamarchi Aurélie , Padilla Françoise , Coste Bertrand , Raoux Matthieu , Crest Marcel , Honoré Eric , Delmas Patrick
Published: August 2006

TRPP2 is a member of the transient receptor potential (TRP) superfamily of cation channels, which is mutated in autosomal dominant polycystic kidney disease (ADPKD). TRPP2 is thought to function with polycystin 1—a large integral protein—as part of a multiprotein complex involved in transducing Ca2+‐dependent information. TRPP2 has been implicated in various biological functions including cell proliferation, sperm fertilization, mating behaviour, mechanosensation and asymmetric gene expression. Although its function as a Ca2+‐permeable cation channel is well established, its precise role in the plasma membrane, the endoplasmic reticulum and the cilium is controversial. Recent studies suggest that TRPP2 function is highly dependent on the subcellular compartment of expression, and is regulated by many interactions with adaptor proteins. This review summarizes the most pertinent evidence about the properties of TRPP2 channels, focusing on the compartment‐specific functions of mammalian TRPP2.
Homocysteine stimulates phosphorylation of NADPH oxidase p47phoxand p67phoxsubunits in monocytes via protein kinase Cβ activation
Authors: Siow Yaw L. , Au-Yeung Kathy K. W. , Woo Connie W. H. , O Karmin
Published: August 2006

Hyperhomocysteinaemia is an independent risk factor for cardiovascular diseases due to atherosclerosis. The development of atherosclerosis involves reactive oxygen species-induced oxidative stress in vascular cells. Our previous study [Wang and O (2001) Biochem. J. 357, 233–240] demonstrated that Hcy (homocysteine) treatment caused a significant elevation of intracellular superoxide anion, leading to increased expression of chemokine receptor in monocytes. NADPH oxidase is primarily responsible for superoxide anion production in monocytes. In the present study, we investigated the molecular mechanism of Hcy-induced superoxide anion production in monocytes. Hcy treatment (20–100 μM) caused an activation of NADPH oxidase and an increase in the superoxide anion level in monocytes (THP-1, a human monocytic cell line). Transfection of cells with p47phox siRNA (small interfering RNA) abolished Hcy-induced superoxide anion production, indicating the involvement of NADPH oxidase. Hcy treatment resulted in phosphorylation and subsequently membrane translocation of p47phox and p67phox subunits leading to NADPH oxidase activation. Pretreatment of cells with PKC (protein kinase C) inhibitors Ro-32-0432 (bisindolylmaleimide XI hydrochloride) (selective for PKCα, PKCβ and PKCγ) abolished Hcy-induced phosphorylation of p47phox and p67phox subunits in monocytes. Transfection of cells with antisense PKCβ oligonucleotide, but not antisense PKCα oligonucleotide, completely blocked Hcy-induced phosphorylation of p47phox and p67phox subunits as well as superoxide anion production. Pretreatment of cells with LY333531, a PKCβ inhibitor, abolished Hcy-induced superoxide anion production. Taken together, these results indicate that Hcy-stimulated superoxide anion production in monocytes is regulated through PKC-dependent phosphorylation of p47phox and p67phox subunits of NADPH oxidase. Increased superoxide anion production via NADPH oxidase may play an important role in Hcy-induced inflammatory response during atherogenesis.
dDYRK2 and Minibrain interact with the chromatin remodelling factors SNR1 and TRX
Authors: Kinstrie Ross , Lochhead Pamela A. , Sibbet Gary , Morrice Nick , Cleghon Vaughn
Published: August 2006

The DYRKs (dual specificity tyrosine phosphorylation-regulated kinases) are a conserved family of protein kinases that autophosphorylate a tyrosine residue in their activation loop by an intra-molecular mechanism and phosphorylate exogenous substrates on serine/threonine residues. Little is known about the identity of true substrates for DYRK family members and their binding partners. To address this question, we used full-length dDYRK2 (Drosophila DYRK2) as bait in a yeast two-hybrid screen of a Drosophila embryo cDNA library. Of 14 independent dDYRK2 interacting clones identified, three were derived from the chromatin remodelling factor, SNR1 (Snf5-related 1), and three from the essential chromatin component, TRX (trithorax). The association of dDYRK2 with SNR1 and TRX was confirmed by co-immunoprecipitation studies. Deletion analysis showed that the C-terminus of dDYRK2 modulated the interaction with SNR1 and TRX. DYRK family member MNB (Minibrain) was also found to co-precipitate with SNR1 and TRX, associations that did not require the C-terminus of the molecule. dDYRK2 and MNB were also found to phosphorylate SNR1 at Thr102in vitro and in vivo. This phosphorylation required the highly conserved DH-box (DYRK homology box) of dDYRK2, whereas the DH-box was not essential for phosphorylation by MNB. This is the first instance of phosphorylation of SNR1 or any of its homologues and implicates the DYRK family of kinases with a role in chromatin remodelling.
Secondary mitochondrial dysfunction in propionic aciduria: a pathogenic role for endogenous mitochondrial toxins
Authors: Schwab Marina A. , Sauer Sven W. , Okun Jürgen G. , Nijtmans Leo G. J. , Rodenburg Richard J. T. , van den Heuvel Lambert P. , Dröse Stefan , Brandt Ulrich , Hoffmann Georg F. , Ter Laak Henk , Kölker Stefan , Smeitink Jan A. M.
Published: August 2006

Mitochondrial dysfunction during acute metabolic crises is considered an important pathomechanism in inherited disorders of propionate metabolism, i.e. propionic and methylmalonic acidurias. Biochemically, these disorders are characterized by accumulation of propionyl-CoA and metabolites of alternative propionate oxidation. In the present study, we demonstrate uncompetitive inhibition of PDHc (pyruvate dehydrogenase complex) by propionyl-CoA in purified porcine enzyme and in submitochondrial particles from bovine heart being in the same range as the inhibition induced by acetyl-CoA, the physiological product and known inhibitor of PDHc. Evaluation of similar monocarboxylic CoA esters showed a chain-length specificity for PDHc inhibition. In contrast with CoA esters, non-esterified fatty acids did not inhibit PDHc activity. In addition to PDHc inhibition, analysis of respiratory chain and tricarboxylic acid cycle enzymes also revealed an inhibition by propionyl-CoA on respiratory chain complex III and α-ketoglutarate dehydrogenase complex. To test whether impairment of mitochondrial energy metabolism is involved in the pathogenesis of propionic aciduria, we performed a thorough bioenergetic analysis in muscle biopsy specimens of two patients. In line with the in vitro results, oxidative phosphorylation was severely compromised in both patients. Furthermore, expression of respiratory chain complexes I–IV and the amount of mitochondrial DNA were strongly decreased, and ultrastructural mitochondrial abnormalities were found, highlighting severe mitochondrial dysfunction. In conclusion, our results favour the hypothesis that toxic metabolites, in particular propionyl-CoA, are involved in the pathogenesis of inherited disorders of propionate metabolism, sharing mechanistic similarities with propionate toxicity in micro-organisms.
Kinetic and chemical analyses of the cytokinin dehydrogenase-catalysed reaction: correlations with the crystal structure
Authors: Popelková Hana , Fraaije Marco W. , Novák Ondřej , Frébortová Jitka , Bilyeu Kristin D. , Frébort Ivo
Published: August 2006

CKX (cytokinin dehydrogenase) is a flavoprotein that cleaves cytokinins to adenine and the corresponding side-chain aldehyde using a quinone-type electron acceptor. In the present study, reactions of maize (Zea mays) CKX with five different substrates (N6-isopentenyladenine, trans-zeatin, kinetin, p-topolin and N-methyl-isopentenyladenine) were studied. By using stopped-flow analysis of the reductive half-reaction, spectral intermediates were observed indicative of the transient formation of a binary enzyme–product complex between the cytokinin imine and the reduced enzyme. The reduction rate was high for isoprenoid cytokinins that showed formation of a charge-transfer complex of reduced enzyme with bound cytokinin imine. For the other cytokinins, flavin reduction was slow and no charge-transfer intermediates were observed. The binary complex of reduced enzyme and imine product intermediate decays relatively slowly to form an unbound product, cytokinin imine, which accumulates in the reaction mixture. The imine product only very slowly hydrolyses to adenine and an aldehyde derived from the cytokinin N6 side-chain. Mixing of the substrate-reduced enzyme with Cu2+/imidazole as an electron acceptor to monitor the oxidative half-reaction revealed a high rate of electron transfer for this type of electron acceptor when using N6-isopentenyladenine. The stability of the cytokinin imine products allowed their fragmentation analysis and structure assessment by Q-TOF (quadrupole–time-of-flight) MS/MS. Correlations of the kinetic data with the known crystal structure are discussed for reactions with different cytokinins.
Direct comparison of nick-joining activity of the nucleic acid ligases from bacteriophage T4
Authors: Bullard Desmond R. , Bowater Richard P.
Published: August 2006

The genome of bacteriophage T4 encodes three polynucleotide ligases, which seal the backbone of nucleic acids during infection of host bacteria. The T4Dnl (T4 DNA ligase) and two RNA ligases [T4Rnl1 (T4 RNA ligase 1) and T4Rnl2] join a diverse array of substrates, including nicks that are present in double-stranded nucleic acids, albeit with different efficiencies. To unravel the biochemical and functional relationship between these proteins, a systematic analysis of their substrate specificity was performed using recombinant proteins. The ability of each protein to ligate 20 bp double-stranded oligonucleotides containing a single-strand break was determined. Between 4 and 37 °C, all proteins ligated substrates containing various combinations of DNA and RNA. The RNA ligases ligated a more diverse set of substrates than T4Dnl and, generally, T4Rnl1 had 50–1000-fold lower activity than T4Rnl2. In assays using identical conditions, optimal ligation of all substrates was at pH 8 for T4Dnl and T4Rnl1 and pH 7 for T4Rnl2, demonstrating that the protein dictates the pH optimum for ligation. All proteins ligated a substrate containing DNA as the unbroken strand, with the nucleotides at the nick of the broken strand being RNA at the 3′-hydroxy group and DNA at the 5′-phosphate. Since this RNA–DNA hybrid was joined at a similar maximal rate by T4Dnl and T4Rnl2 at 37 °C, we consider the possibility that this could be an unexpected physiological substrate used during some pathways of ‘DNA repair’.
Supervised membrane swimming: small G-protein lifeguards regulate PIPK signalling and monitor intracellular PtdIns(4,5)P2 pools
Authors: Santarius Megan , Lee Chang Ho , Anderson Richard A.
Published: August 2006

Regulation of PIPK (phosphatidylinositol phosphate kinase) and PtdIns(4,5)P2 signalling by small G-proteins and their effectors is key to many biological functions. Through selective recruitment and activation of different PIPK isoforms, small G-proteins such as Rho, Rac and Cdc42 modulate actin dynamics and cytoskeleton-dependent cellular events in response to extracellular signalling. These activities affect a number of processes, including endocytosis, bacterial penetration into host cells and cytolytic granule-mediated targeted cell killing. Small G-proteins and their modulators are also regulated by phosphoinositides through translocation and conformational changes. Arf family small G-proteins act at multiple sites as regulators of membrane trafficking and actin cytoskeletal remodelling, and regulate a feedback loop comprising phospholipase D, phosphatidic acid, PIPKs and PtdIns(4,5)P2, contributing to enhancement of PtdIns(4,5)P2-mediated cellular events and receptor signalling. Na+, Kir (inwardly rectifying K+), Ca2+ and TRP (transient receptor potential) ion channels are regulated by small G-proteins and membrane pools of PtdIns(4,5)P2. Yeast phosphatidylinositol 4-phosphate 5-kinases Mss4 and Its3 are involved in resistance against disturbance of sphingolipid biosynthesis and maintenance of cell integrity through the synthesis of PtdIns(4,5)P2 and downstream signalling through the Rom2/Rho2 and Rgf1/Rho pathways. Here, we review models for regulated intracellular targeting of PIPKs by small G-proteins and other modulators in response to extracellular signalling. We also describe the spatial and temporal cross-regulation of PIPKs and small G-proteins that is critical for a number of cellular functions.
Serum phospholipid fatty acid profile and dietary intake in an adult Mediterranean population with cystic fibrosis
Authors: Olveira Gabriel , Dorado Antonio , Olveira Casilda , Padilla Alicia , Rojo-Martínez Gemma , García-Escobar Eva , Gaspar Inmaculada , Gonzalo Montserrat , Soriguer Federico
Published: August 2006

The relative importance of the usual diet in serum phospholipids in subjects with cystic fibrosis (CF) has been poorly studied. To compare the fatty acid profile in serum phospholipids from adult CF subjects with that of healthy subjects, and determine the role of the normal diet in this profile, we studied thirty-seven adult CF subjects with stable pulmonary disease and thirty-seven healthy controls matched for age, sex and nutritional status. A dietary questionnaire was obtained, anthropometric data were recorded, and the fatty acid profile measured by GLC. Compared with the controls, the percentages of myristic, palmitoleic and stearic acids and total MUFA were significantly higher in the CF group, and DHA, linoleic acid, total PUFA andn−6 fatty acids were significantly lower in the CF group. The CF subjects with worse pulmonary function and with pancreatic insufficiency had significantly lower levels of linoleic andn−6 fatty acids. The total energy intake was significantly higher in the CF subjects, although the energy distribution in the CF subjects and the controls was not different for the carbohydrates, lipids and proteins. No differences were detected in fat intake for MUFA (51 (sd 4)v. 52 (sd 4) %) or saturated fatty acids (33·5 (sd 5)v. 31·2 (sd 3·8) %), but the PUFA were slightly lower in the CF subjects (15·4 (sd 4·5)v. 17·4 (sd 4·2) %;P=0·02). The usual dietary intake of fatty acids by adult CF subjects does not appear to explain the difference in the fatty acid profile compared with controls. This suggests an abnormal fatty acid metabolism in CF subjects.
Bioavailability of β-carotene (βC) from purple carrots is the same as typical orange carrots while high-βC carrots increase βC stores in Mongolian gerbils(Meriones unguiculatus)
Authors: Dosti Mandy Porter , Mills Jordan P. , Simon Philipp W. , Tanumihardjo Sherry A.
Published: August 2006

Vitamin A (VA) deficiency is a worldwide public health problem. Biofortifying existing sources of β-carotene (βC) and increasing dietary βC could help combat the issue. Two studies were performed to investigate the relative βC bioavailability of a βC supplement to purple, high-βC orange, and typical orange carrots using Mongolian gerbils (Meriones unguiculatus). In study 1, which used a traditional bioavailability design, gerbils (n32) received a diet containing orange, purple, or white carrot powder, or white carrot powder +a βC supplement. In study 2, which included βC-biofortified carrots, gerbils (n39) received orange, high-βC orange, purple, or white carrot powder in their diet. Both studies lasted 21 d and the gerbils were killed to determine the effect of carrot type or supplement on serum and liver βC, α-carotene, and VA concentrations. Liver stores of βC or VA in the gerbils did not differ between orange and purple carrot diets when equal amounts of βC from each of the diets were consumed (P>0·05). Both the orange and purple carrot diet resulted in higher liver VA compared with the supplement (P<0·05). High-βC carrots resulted in more than 2-fold higher βC and 1·1 times greater VA liver stores compared with typical orange carrots (P<0·05). These results suggest that high-βC carrots may be an alternative source of VA to typical carrots in areas of VA deficiency. Second, phenolics including anthocyanins and phenolic acids in purple carrot do not interfere with the bioavailability of βC from purple carrots.
Ghrelin: a hormone regulating food intake and energy homeostasis
Authors: Gil-Campos Mercedes , Aguilera Concepción María , Cañete Ramón , Gil Angel
Published: August 2006

Regulation of energy homeostasis requires precise coordination between peripheral nutrient-sensing molecules and central regulatory networks. Ghrelin is a twenty-eight-amino acid orexigenic peptide acylated at the serine 3 position mainly with ann-octanoic acid, which is produced mainly in the stomach. It is the endogenous ligand of the growth hormone secretagogue (GHS) receptors. Since plasma ghrelin levels are strictly dependent on recent food intake, this hormone plays an essential role in appetite and meal initiation. In addition, ghrelin is involved in the regulation of energy homeostasis. The ghrelin gene is composed of four exons and three introns and renders a diversity of orexigenic peptides as well as des-acyl ghrelin and obestatin, which exhibit anorexigenic properties. Ghrelin stimulates the synthesis of neuropeptide Y (NPY) and agouti-related protein (AgRP) in the arcuate nucleus neurons of the hypothalamus and hindbrain, which in turn enhance food intake. Ghrelin-expressing neurons modulate the action of both orexigenic NPY/AgRP and anorexigenic pro-opiomelanocortin neurons. AMP-activated protein kinase is activated by ghrelin in the hypothalamus, which contributes to lower intracellular long-chain fatty acids, and this appears to be the molecular signal for the expression of NPY and AgRP. Recent data suggest that ghrelin has an important role in the regulation of leptin and insulin secretion and vice versa. The present paper updates the effects of ghrelin on the control of energy homeostasis and reviews the molecular mechanisms of ghrelin synthesis, as well as interaction with GHS receptors and signalling. Relationships with leptin and insulin in the regulation of energy homeostasis are addressed.
Variations in daily intakes of myristic and α-linolenic acids in sn-2 position modify lipid profile and red blood cell membrane fluidity
Authors: Dabadie Henry , Motta Claude , Peuchant Evelyne , LeRuyet Pascale , Mendy François
Published: August 2006

The present study evaluated the effects of moderate intakes of myristic acid (MA), at 1·2% and 1·8% of total energy (TE), associated with a 0·9% TE intake of α-linolenic acid (ALA) on lipid and fatty acid profiles and red blood cell membrane fluidity. Twenty-nine monks without dyslipidaemia were enrolled in a 1-year nutritional study in which two experimental diets were tested for 3 months each: diet 1, MA 1·2% and ALA 0·9%; diet 2, MA 1·8% and ALA 0·9%. A control diet (MA 1·2%, ALA 0·4%) was given 3 months before diets 1 and 2. Thus, two different levels of MA (1·2%, 1·8%) and ALA (0·4%, 0·9%) were tested. Intakes of other fatty acids were at recommended levels. Samples were obtained on completion of all three diets. For fluidity analysis, the red blood cells were labelled with 16-doxylstearate and the probe incorporated the membrane where relaxation-correlation time was calculated. Diet 1 was associated with a decrease in total cholesterol, in LDL-cholesterol, in triacylglycerols and in the ratio of total to HDL-cholesterol; ALA and EPA levels were increased in both phospholipids and cholesterol esters. Diet 2 was associated with a decrease in triacylglycerols and in the ratios of total to HDL-cholesterol and of triacylglycerols to HDL-cholesterol, and with an increase in HDL-cholesterol; EPA levels were decreased in phospholipids and cholesterol esters. Red blood cell membrane fluidity was increased in both diets (P<0·0001), but the higher increase was obtained with diet 1, mainly in the oldest subjects. Intakes of myristic acid (1·2%TE) and ALA (0·9%TE), both mainly in the sn-2 position, were associated with favourable lipid andn−3 long-chain fatty acid profiles. These beneficial effects coexisted with particularly high membrane fluidity, especially among the oldest subjects.
Replacing dietary fish oil by vegetable oils has little effect on lipogenesis, lipid transport and tissue lipid uptake in rainbow trout (Oncorhynchus mykiss)
Authors: Richard Nadège , Kaushik Sadasivam , Larroquet Laurence , Panserat Stéphane , Corraze Geneviève
Published: August 2006

In order to investigate the effects of dietary lipid sources on mechanisms involved in lipid deposition, two groups of rainbow trout were fed from first-feeding to the commercial size of 1kg (for 62 weeks) with two diets differing only by lipid source: 100% fish oil or 100% blend of vegetable oils (55% rapeseed oil, 30% palm oil, 15% linseed oil). The activities and levels of gene expression of lipogenic enzymes (fatty acid synthetase, glucose-6-phosphate dehydrogenase and malic enzyme) in liver and of lipoprotein lipase in perivisceral adipose tissue, white muscle and liver were determined. Transport of lipid was studied by determining lipid composition of plasma and lipoprotein classes. We also examined the clearance of LDL by assaying the level of LDL receptor gene expression in several tissues. Total replacement of dietary fish oil by the blend of vegetable oils did not affect growth of rainbow trout and did not modify muscle lipid content. Hepatic lipogenesis and lipid uptake in perivisceral adipose tissue, white muscle and liver were also not modified by dietary treatments. Diets containing the blend of vegetable oils induced a decrease in plasma cholesterol and LDL. In trout fed the vegetable oils diet, expression of LDL receptor gene in the liver was down-regulated.
Taurine status and response to intravenous taurine supplementation in adults with short-bowel syndrome undergoing long-term parenteral nutrition: a pilot study
Authors: Schneider Stéphane M. , Joly Françoise , Gehrardt Marie-France , Badran Abdul M. , Myara Anne , Thuillier François , Coudray-Lucas Colette , Cynober Luc , Trivin François , Messing Bernard
Published: August 2006

Taurine deficiency in patients on long-term parenteral nutrition may be involved in cholestasis. We aimed to assess plasma taurine and tauro-conjugated bile acids in adults with short-bowel syndrome and their response to intravenous taurine. Thirty-two adult patients, who had been on taurine-free parenteral nutrition for a mean of 59(SE14) months for short-bowel syndrome, were studied retrospectively. In a second study, a subgroup of ten patients with chronic cholestasis received taurine-enriched (6·0(SE0·6)mg/kg per d) parenteral nutrition for 55(SE13) months. Post-absorptive plasma taurine and bile acid concentrations were measured and liver function tests routinely sampled. At baseline, plasma taurine was lower in patients with a jejunal length of less than 35cm (group A,n16) than in those with a jejunal length of 35cm or more (group B,n16): 43(SE3)v. 58(SE4)μmol/l (P=0·01). The groups were no different in terms of chronic cholestasis (1/6v.1/6 patients), total bile acids (26(SE13)v.14(SE5)μmol/l) or the ratio of tauro-conjugated:glyco-conjugated bile acids (5(SE2)v.8(SE 4)%, usual range 30–60%). After supplementation, there was an increase in plasma taurine level (63(SE8)v. 43(SE4),P=0·007) but was no change in either total bile acids or the ratio of tauro-conjugated: glyco-conjugated bile acids. There was a significant decrease in aspartate aminotransferase level. Long-term parenteral nutrition for short-bowel syndrome is associated with an impaired tauro-conjugation of bile acids (enterohepatic pool), irrespective of plasma taurine level (systemic pool) and despite long-term taurine intravenous supplementation.
Plasma responses in human subjects after ingestions of multiple doses of natural α-cryptoxanthin: a pilot study
Authors: Schlatterer Jörg , Breithaupt Dietmar E. , Wolters Maike , Hahn Andreas
Published: August 2006

Xanthophylls have attracted a lot of interest since their health benefits were documented. Unfortunately, studying their intestinal absorption is often affected by high baseline levels present in the fasting plasma. As α-cryptoxanthin is rarely found in the traditional European diet, its concentration in human plasma is extremely low. A pilot human intervention study was designed using α-cryptoxanthin for the first time as a marker xanthophyll in a minimally formulated cellulose-based supplement. α-Cryptoxanthin was administered in gelatin soft-gel capsules in multiple doses of 156μg/d to three male volunteers (age 27·3 (sd 4·7) years; BMI 21·6 (sd 0·3) kg/m2) for 16d after a 2-week carotenoid depletion period. Fasting blood samples were taken before the intervention and after 3, 6, 9, 13 and 16d. Plasma HPLC analyses allowed for determination of the concentration; liquid chromatography–MS in the single ion monitoring mode was used to confirm peak assignment. The concentrations of α-cryptoxanthin increased significantly after only 3d of supplementation. The concentration-time plots showed a characteristic shape with a first maximum after day 6, a decline until day 9 and a gradual second rise until the end of the study. Standardisation of plasma α-cryptoxanthin concentrations to triacylglycerol or total cholesterol did not influence the characteristics. The maximum concentrations reached at the end of the intervention period ranged from 0·077 to 0·160μmol/l. These results suggest a high intestinal absorption and an enrichment of α-cryptoxanthin in the plasma even from a minimally formulated cellulose-based supplement.
Genetic diversity of pummelo (Citrus grandis Osbeck) and its relatives based on simple sequence repeat markers
Authors: Yong Liu , De-Chun Liu , Bo Wu , Zhong-Hai Sun
Published: August 2006

Genetic diversity in 122 accessions of pummelo (Citrus grandis Osbeck) and its related varieties was assessed using simple sequence repeat (SSR) markers. Thirty-one pairs of SSR informative primers generated a total of 335 alleles. The average number of alleles per locus was 9.85. The value of allelic polymorphism information content (PIC) ranged from 0.1939 to 0.9073, with an average of 0.7085 per primer. The 122 accessions of pummelo and its related varieties could be clustered into seven groups by the unweighted pair-group method arithmetic average (UPGMA), in which the 110 pummelo accessions could be divided into 18 subgroups at similarity coefficient of 0.712. These subgroups were mainly composed of the Shatian pummelo variety group, the Wendan variety group and many of the hybrid pummelo groups. The classification method can be used in targeting many varieties in order to widen the genetic background of pummelo.
Establishment of a highly efficient regeneration system for in vitro culture of young wheat spikes
Authors: Lin-Shu Zhao , Lu-Xiang Liu , Jing Wang , Qi-Cheng Zheng , Hui-Jun Guo , Shi-Rong Zhao , Wen-Hua Chen
Published: August 2006

This study used three winter wheat (Triticum aestivum L.) genotypes (H6756, H311 and SP8581) to compare the effects of sampling time, callus induction media, differentiation media and rooting media on in vitro culture of young spikes in wheat. In all these three genotypes, the frequencies of green plantlet differentiation were high when their young spikes were cultured between the stages of protective glume primordium formation and pistil and stamen primordium formation, but low at other stages. The optimum medium for callus induction was Murashige and Skoog (MS) medium+2 mg/l 2,4-dichlorophenoxyacetic acid (2,4-D). The optimum green plantlet differentiation medium was MS medium. Some abnormal plantlets regenerated from calli. When these plantlets were transferred to another differentiation medium [MS+1.0 mg/l 1-naphthaleneacetic acid (NAA)+0.2 mg/l 6-benzylaminopurine (6-BA)], shoot formation and elongation were induced. This allowed 90.91% of them to develop into normal green plantlets. The optimum rooting medium was 1/2MS+0.2 mg/l 3-Indolylacetonitrile (IAA)+80 g/l sucrose. An efficient regeneration system for young spike culture of wheat was set up based on such methods. Using this wheat-regeneration system, young spikes and immature embryos of 17 genotypes of wheat were in vitro cultured to study and compare the callus induction frequencies and green plantlet differentiation frequencies. The results of two successive years showed that in 15 out of the 17 genotypes (88.24%) the green plantlet differentiation frequencies were higher than those of immature embryos by 6.2–65.1%. These results showed that the regeneration system established in this trial for young spike culture of wheat was effective.
Applications of microsatellite markers in studies of genetics and breeding of fish
Authors: Xiao-Gu Zhang , Jin-Gou Tong , Bang-Xi Xiong
Published: August 2006

The microsatellite, or short sequence repeat (SSR), is a powerful genetic marker, useful in many areas of fish genetics and breeding. Polymorphic microsatellite loci have been frequently applied to the analysis of genetic diversity, population genetic structure, and genomic mapping. These co-dominant markers have also been applied to the classification and systematics, parentage identification, germplasm conservation, and breeding programme of food fish.
A nested PCR-based method for detection ofStreptococcus agalactiae16S rRNA in milk and its application
Authors: Yu-Ping Jia , Dong-Shun Zhou , Hong-Kun Zhao , Ren-Zhong Wan , Wen-Qiang Liu , Jing-Dong Hu
Published: August 2006

Bovine mastitis caused byStreptococcus agalactiaeis mainly subclinical and therefore can be diagnosed only in the laboratory. A nested polymerase chain reaction (PCR)-based method for specific, sensitive and rapid detection ofS. agalactiaein raw milk was developed. The general streptococci primers, which anneal to conserved areas within the 16S rRNA subunit gene, were used as positive controls. The specificity ofS. agalactiaeprimers is based on various areas within conserved areas of the 16S rRNA genes ofS. agalactiae. Results have indicated that the method enables the detection of 1 CFU/ml ofS. agalactiaein raw milk after enrichment, followed by DNA extraction using a rapid and simple procedure developed for this purpose, and specific PCR reaction. The method developed can be used efficiently in the early infectious status investigation ofS. agalactiaein the dairy herd and in prevention and control ofS. agalactiaespread in a herd.
Language impairments in sign language: breakthroughs and puzzles
Authors: Morgan Gary , Herman Rosalind , Woll Bencie
Published: August 2006

Background: Specific language impairment has previously solely been documented for children acquiring spoken languages, despite informal reports of deaf children with possible sign language disorder. The paper reports the case of a deaf child exposed to British Sign Language (BSL) from birth, who has significant developmental deficits in the comprehension and production of BSL grammar based on formal assessment and linguistic analyses of his sign communication in comparison with age‐matched unimpaired signers.

Results: It is shown that linguistic difficulties with BSL verb morphology underlie the child's poor performance compared with same‐age native signers.

Conclusions: The appearance of linguistic impairments in sign and spoken languages in comparable domains supports cross‐linguistic and modality free theories of specific language impairment.
Tetanus toxin is internalized by a sequential clathrin-dependent mechanism initiated within lipid microdomains and independent of epsin1
Authors: Deinhardt Katrin , Berninghausen Otto , Willison Hugh J. , Hopkins Colin R. , Schiavo Giampietro
Published: August 2006

Ligand–receptor complexes are internalized by a variety of endocytic mechanisms. Some are initiated within clathrin-coated membranes, whereas others involve lipid microdomains of the plasma membrane. In neurons, where alternative targeting to short- or long-range trafficking routes underpins the differential processing of synaptic vesicle components and neurotrophin receptors, the mechanism giving access to the axonal retrograde pathway remains unknown. To investigate this sorting process, we examined the internalization of a tetanus neurotoxin fragment (TeNT HC), which shares axonal carriers with neurotrophins and their receptors. Previous studies have shown that the TeNT HC receptor, which comprises polysialogangliosides, resides in lipid microdomains. We demonstrate that TeNT HC internalization also relies on a specialized clathrin-mediated pathway, which is independent of synaptic vesicle recycling. Moreover, unlike transferrin uptake, this AP-2–dependent process is independent of epsin1. These findings identify a pathway for TeNT, beginning with the binding to a lipid raft component (GD1b) and followed by dissociation from GD1b as the toxin internalizes via a clathrin-mediated mechanism using a specific subset of adaptor proteins.