bluuebunny/crossref_metadata_2025 huggingface dataset:
The composition of polyunsaturated fatty acids in erythrocytes of lactating mothers and their infants
Authors: Jørgensen Marianne Hørby , Nielsen Pernille Kjær , Michaelsen Kim Fleischer , Lund Pia , Lauritzen Lotte
Published: December 2005

Long‐chain polyunsaturated fatty acids (LCPUFA) in breastmilk, specifically docosahexaenoic acid (DHA), are important for infant brain development. Accretion of DHA in the infant brain is dependent on DHA‐status, intake and metabolism. The aim of this study was to describe changes in maternal and infant erythrocyte (RBC) DHA‐status during the first four months of lactation. We examined 17 mothers and their term infants at 1, 2 and 4 months of age. Milk samples and RBC from the mothers and infants were obtained and analysed for fatty acid composition. Comparative analysis of the results showed that the content of DHA in maternal RBC‐phosphatidylcholine (PE) decreased over the four month period and this was not accompanied by a decrease in DHA in infant RBC‐PE (P = 0.005). The ratio of n‐6 PUFA to n‐3 PUFA increased over time in maternal RBC‐PE, but not in infant RBC‐PE (P < 0.001). The level of 22:5n‐6 and the ratio of LCPUFA to precursor PUFAs in infant RBC was higher than in maternal RBC phospholipids. (P = and P < 0.001 respectively). We found a decrease in the level of LCPUFA in milk, specifically AA. However, we did not observe a significant decrease in milk DHA, which may have been due to two outliers. These results indicate better DHA‐status and a higher n‐3/n‐6 PUFA in RBC of infants than in mothers. Whether these differences reflect preferential n‐3 PUFA transfer via breastmilk or differences in PUFA‐metabolism and utilization remains to be shown.
Segmental ulcerative vasculitis: a cutaneous manifestation of Takayasu's arteritis
Authors: Dourmishev Assen L , Serafimova Dimitrina K , Vassileva Snejina G , Dourmishev Lyubomir A , Schwartz Robert A
Published: December 2005

A 16‐year‐old girl with pyoderma gangrenosum (PG)‐like skin lesions on the extremities, trunk and face developed Takayasu's arteritis (TA; pulseless disease). After 3 years under maintenance cyclosporin A therapy, the patient developed an ischaemic cerebral accident. Severe obstruction of both subclavian and left carotid arteries was found by Doppler sonography, angiography and computerised axial tomography. Evolution of this disease showed some characteristic findings: (a) PG‐like lesions as the first cutaneous manifestation of pulseless disease; (b) methotrexate and cyclosporin A giving good results for the cutaneous lesions, but apparently not exerting an influence on the evolution of TA and the fatal outcome. This morphologic pattern may reflect underlying TA or Wegener's arteritis, and should be termed segmental ulcerative vasculitis.
High glucose inhibits human epidermal keratinocyte proliferation for cellular studies on diabetes mellitus
Authors: Terashi Hiroto , Izumi Kenji , Deveci Mustafa , Rhodes Lenore M , Marcelo Cynthia L
Published: December 2005

In order to more clarify the delayed wound healing in diabetes mellitus, we cultured the human epidermal keratinocytes in both 6 mM (control group) and 12 mM glucose (high‐glucose group) of ‘complete’ MCDB 153 medium. Hyperglycaemia slowed the rate of their proliferation and inhibited their DNA synthesis and the production of total proteins. By 1 month after primary seeding in high‐glucose group, the cells ceased their proliferation, whereas the cells in control group grew for more than 40 days. Mean population doublings in high‐glucose group was 5·27 (vs. 7·25 in control, P = 0·001), and mean population doubling time during 1 month in high glucose group was 5·43 days (vs. 3·65 days in control, P = 0·02). They indicate that prolonged exposure to high glucose decreases the replicative life span of human epidermal keratinocytes in vitro. Furthermore, analysis of fatty acid contents in membrane phospholipids with thin‐layer and gas chromatography showed no difference between the cultured keratinocytes in both conditions. Immunocytochemical staining of glucose transporter 1 shows that 28·1% of cells in high‐glucose group were almost twice positive of those in control group (13·2%, P = 0·008). The mechanism of the ill effects of high glucose on epidermal keratinocytes is not so far clear, but it indicates the possibility of any direct effect of hyperglycaemia on glucose metabolism without changing lipid metabolism on cell membrane. The high‐glucose group presented in this report can be available as an in vitro valuable study model of skin epidermal condition on diabetes mellitus.
COLLECTIVE EFFICACY, AUTHORITATIVE PARENTING AND DELINQUENCY: A LONGITUDINAL TEST OF A MODEL INTEGRATING COMMUNITY‐AND FAMILY‐LEVEL PROCESSES*
Authors: SIMONS RONALD L. , SIMONS LESLIE GORDON , BURT CALLIE HARBIN , BRODY GENE H. , CUTRONA CAROLYN
Published: December 2005

In this paper, we develop and test hypotheses on how authoritative parenting and collective efficacy combine to increase a child's risk of affiliating with deviant peers and engaging in delinquent behavior. Analyses using two waves of data from a sample of several hundred African American caregivers and their children largely supported the predictions. Over time, increases in collective efficacy within a community were associated with increases in authoritative parenting. Further, both authoritative parenting and collective efficacy served to deter affiliation with deviant peers and involvement in delinquent behavior. Finally, there was evidence of an amplification process whereby the deterrent effect of authoritative parenting on affiliation with deviant peers and delinquency was enhanced when it was administered within a community with high collective efficacy.
Structure‐based Optimization of MurF Inhibitors
Authors: Stamper Geoffrey F. , Longenecker Kenton L. , Fry Elizabeth H. , Jakob Clarissa G. , Florjancic Alan S. , Gu Yu‐Gui , Anderson David D. , Cooper Curt S. , Zhang Tianyuan , Clark Richard F. , Cia Yingna , Black‐Schaefer Candace L. , Owen McCall J. , Lerner Claude G. , Hajduk Philip J. , Beutel Bruce A. , Stoll Vincent S.
Published: December 2005

The d‐Ala‐d‐Ala adding enzyme (MurF) from Streptococcus pneumoniae catalyzes the ATP‐dependent formation of the UDP‐MurNAc‐pentapeptide, a critical component of the bacterial cell wall. MurF is a potential target for antibacterial design because it is unique to bacteria and performs an essential non‐redundant function in the bacterial cell. The recent discovery and subsequent cocrystal structure determination of MurF in complex with a new class of inhibitors served as a catalyst to begin a medicinal chemistry program aimed at improving their potency. We report here a multidisciplinary approach to this effort that allowed for rapid generation of cocrystal structures, thereby providing the crystallographic information critical for driving the inhibitor optimization process. This effort resulted in the discovery of low‐nanomolar inhibitors of this bacterial enzyme.
Length‐dependent changes in voluntary activation, maximum voluntary torque and twitch responses after eccentric damage in humans
Authors: Prasartwuth O. , Allen T. J. , Butler J. E. , Gandevia S. C. , Taylor J. L.
Published: December 2005

To assess the contribution of central and peripheral factors to changes in maximum voluntary force and its length dependence after eccentric muscle damage, voluntary and twitch torque were measured across a wide angular range, along with voluntary activation using twitch interpolation. Isometric torque from both maximum voluntary contractions (MVCs) and paired twitches to motor nerve stimulation were measured from 60 to 150 deg elbow flexion in 10 deg increments in eight subjects. Optimal angles were determined by curve fitting. Each subject then performed eccentric contractions until voluntary torque had decreased by ∼40%. Measurements were repeated at 2 h, 1 day and 8 days post‐exercise to follow acute and longer‐term changes. Before exercise, the optimal angle was in the mid‐range (93 ± 10 deg; mean ±s.d.) for MVCs, and at a more extended elbow angle for the twitch (106 ± 6 deg, P < 0.05). Voluntary activation was generally high (> 94%) but depended on elbow angle, with activation being ∼4% lower at the most flexed compared to the most extended angle. Two hours after exercise, MVCs decreased 40%, while twitch torque declined 70%. All subjects showed a shift in optimal angle to longer muscle lengths for MVCs (17 ± 16 deg at 2 h, 14 ± 7 deg at day 1, P < 0.05). This shift contributed minimally (∼3%) to the reduction in torque at 90 deg, as the torque–angle relation was relatively flat around the optimum. The twitch showed a smaller shift (∼4 deg) to longer lengths which was not statistically significant. Voluntary activation was significantly impaired in the early stages after exercise (2 h and day 1, P < 0.05), particularly at short muscle lengths. By 8 days after exercise, the optimal angle had returned to pre‐exercise values, but MVC, twitch torque and voluntary activation had not fully recovered. Eccentric exercise causes a short‐term shift in the optimal angle for MVCs and produces a length‐dependent impairment in voluntary activation. Therefore, it appears that both central and peripheral factors limit muscle performance following eccentric damage, with limits to voluntary drive being especially important at short lengths.
Trial by fire: a multivariate examination of the relation between job tenure and work injuries
Authors: Breslin F C , Smith P
Published: December 2005

Aims:This study examined the relation between months on the job and lost-time claim rates, with a particular focus on age related differences.

Methods:Workers’ compensation records and labour force survey data were used to compute claim rates per 1000 full time equivalents. To adjust for potential confounding, multivariate analyses included age, sex, occupation, and industry, as well job tenure as predictors of claim rates.

Results:At any age, the claim rates decline as time on the job increases. For example, workers in the first month on the job were over four times more likely to have a lost-time claim than workers with over one year in their current job. The job tenure injury associations were stronger among males, the goods industry, manual occupations, and older adult workers.

Conclusions:The present results suggest that all worker subgroups examined show increased risk when new on the job. Recommendations for improving this situation include earlier training, starting workers in low hazard conditions, reducing job turnover rates in firms, and improved monitoring of hazard exposures that new workers encounter.
Laboratory work and pregnancy outcomes: a study within the National Birth Cohort in Denmark
Authors: Zhu J L , Knudsen L E , Andersen A-M N , Hjollund N H , Olsen J
Published: December 2005

Aims:To examine pregnancy outcomes in women doing laboratory work.

Methods:Using data from the Danish National Birth Cohort (1997–2003), the authors conducted a prospective cohort study of 1025 female laboratory technicians and 8037 female teachers (as reference). The laboratory technicians were asked about laboratory work tasks during pregnancy in an interview (at around 16 weeks of gestation). Pregnancy outcomes were obtained by linking the cohort to the national registers. Hazard ratios (HRs) of late fetal loss and diagnosing of congenital malformations were calculated by using Cox regression, and odds ratios (ORs) of preterm birth and small for gestational age were calculated by using logistic regression.

Results:Overall, there were no significant differences in pregnancy outcomes between laboratory technicians and teachers. However, we found that laboratory technicians working with radioimmunoassay or radiolabelling had an increased risk of preterm birth (OR = 2.2, 95% CI 0.8 to 6.2 for radioimmunoassay, and OR = 1.9, 95% CI 0.8 to 4.6 for radiolabelling) and “major” malformations (HR = 2.1, 95% CI 1.0 to 4.7 for radioimmunoassay, and HR = 1.8, 95% CI 0.9 to 3.7 for radiolabelling). The ORs of preterm birth doubled for women working with these tasks every day or several times a week. When an exposure matrix was applied, an increased risk of “major” malformations for exposure to organic solvents was seen.

Conclusions:The results did not indicate any high risk of reproductive failures in laboratory technicians in general. Exposure to radioisotopes may carry a high risk of preterm birth and congenital malformations. This finding deserves further investigation.
HIGHER ORDER CELLULAR AUTOMATA
Authors: BAAS NILS A. , HELVIK TORBJØRN
Published: December 2005

We introduce a class of dynamical systems called Higher Order Cellular Automata (HOCA). These are based on ordinary CA, but have a hierarchical, or multi-level, structure and/or dynamics. We present a detailed formalism for HOCA and illustrate the concepts through four examples. Throughout the article we emphasize the principles and ideas behind the construction of HOCA, such that these easily can be applied to other types of dynamical systems. The article also presents new concepts and ideas for describing and studying hierarchial dynamics in general.
A FORMAL THEORY OF EARLY COGNITION DEVELOPMENT
Authors: OKADOME TAKESHI
Published: December 2005

The formal theory of the development of early perception and motor control presented here deals with cognitive development as a mapping from a finite set of given experiences to a set of perceptual and motor-control functions. The theory involves seven constraints that uniquely define the mapping. The compatibility with observational phenomena and sufficiency of these constraints shows the validity of the theory. The principle underlying these constraints is a coding by the most efficient representation of information. The efficiency of representation is evaluated by the coding redundancy of given experiences defined as the number of real numbers that characterize experiences plus the size of the minimum continuous decoding function. The coding redundancy of experiences by the most efficient representation corresponds to the Kolmogorov complexity of the experiences. The mapping accounts for the dependence on neonatal experience of the development of perceptual and motor-control functions. This theory of development can also be seen as a metatheory of cognition that presents us a unified view of the diversity of perceptual and motor-control modules.
IN SILICOPHENOTYPIC SCREENING METHOD OF MUTANTS BASED ON STATISTICAL MODELING OF GENETICALLY MIXED SAMPLES
Authors: KAMINUMA ELI , HEIDA NAOHIKO , YOSHIZUMI TAKESHI , NAKAZAWA MIKI , MATSUI MINAMI , TOYODA TETSURO
Published: December 2005

In comprehensive functional genomics projects, systematic analysis of phenotypes is vital. However, conventional phenotypic screening is done mainly by imprecise visual observation of qualitative traits, and, therefore, in silico screening techniques for quantitative traits are required. In this report, we propose in silico phenotypic screening method that utilizes a Gaussian mixture model for the trait distribution in the offspring of a mutagenized line and the likelihood ratio test between the estimated Gaussian mixture model and the wild-type single Gaussian model. In order to evaluate the proposed method, we performed a screening experiment using real trait data of Arabidopsis. In this experiment, the proposed screening method properly distinguished the mutant line from the wild-type line. Furthermore, we conducted power analysis of the proposed method and two conventional methods under various simulated conditions of sample size and distribution of trait frequency. The result of the power analysis confirmed the effectiveness of the proposed method compared to the conventional methods.
REFINEMENT OF NMR-DETERMINED PROTEIN STRUCTURES WITH DATABASE DERIVED DISTANCE CONSTRAINTS
Authors: CUI FENG , JERNIGAN ROBERT , WU ZHIJUN
Published: December 2005

The protein structures determined by NMR (Nuclear Magnetic Resonance Spectroscopy) are not as detailed and accurate as those by X-ray crystallography and are often underdetermined due to the inadequate distance data available from NMR experiments. The uses of NMR-determined structures in such important applications as homology modeling and rational drug design have thus been severely limited. Here we show that with the increasing numbers of high quality protein structures being determined, a computational approach to enhancing the accuracy of the NMR-determined structures becomes possible by deriving additional distance constraints from the distributions of the distances in databases of known protein structures. We show through a survey on 462 NMR structures that, in fact, many inter-atomic distances in these structures deviate considerably from their database distributions and based on the refinement results on 10 selected NMR structures that these structures can actually be improved significantly when a selected set of distances are constrained within their high probability ranges in their database distributions.
A TUTORIAL ON MARKOV MODELS BASED ON MENDEL'S CLASSICAL EXPERIMENTS
Authors: THORVALDSEN STEINAR
Published: December 2005

Hidden Markov Models (HMM) can be extremely useful tools for the analysis of data from biological sequences, and provide a probabilistic model of protein families. Most reviews and general introductions follow the excellent tutorial by Rabiner,1where the focus is outside biology. Mendel's famous experiments in plant hybridisation were published in 1866 and are often considered the icebreaking work of modern genetics. He had no prior knowledge of the dual nature of genes, but through a series of experiments he was able to anticipate the hidden concept and name it "Elemente". In this paper we present the background, theory and algorithms of HMM based on examples from Mendel's experiments, and introduce the toolbox "mendelHMM". This approach is considered to have some intuitive advantages in a biological and bioinformatical setting. Applications to analysing bio-sequences like nucleic acids and proteins are also discussed.
REDUCTION AND UNFOLDING FOR QUANTUM SYSTEMS: THE HYDROGEN ATOM
Authors: D'AVANZO ANTONELLA , MARMO GIUSEPPE , VALENTINO ALESSANDRO
Published: December 2005

In this paper we propose a "quantum reduction procedure" based on the reduction of algebras of differential operators on a manifold. We use these techniques to show, in a systematic way, how to relate the hydrogen atom to a family of quantum harmonic oscillators, by the means of the Kustaahneimo–Stiefel fibration.
THE MOMENTUM MAP FOR NONHOLONOMIC FIELD THEORIES WITH SYMMETRY
Authors: VANKERSCHAVER JORIS
Published: December 2005

We introduce a suitable generalization of the momentum map for nonholonomic field theories and prove a covariant form of the nonholonomic momentum equation. We show that these covariant objects coincide with their counterparts in mechanics by making the transition to the Cauchy formalism.
ASYMPTOTIC SCALING SYMMETRIES FOR NONLINEAR PDES
Authors: GAETA GIUSEPPE , MANCINELLI ROSARIA
Published: December 2005

In some cases, solutions to nonlinear PDEs happen to be asymptotically (for large x and/or t) invariant under a group G which is not a symmetry of the equation. After recalling the geometrical meaning of symmetries of differential equations — and solution-preserving maps — we provide a precise definition of asymptotic symmetries of PDEs; we deal in particular, for ease of discussion and physical relevance, with scaling and translation symmetries of scalar equations. We apply the general discussion to a class of "Richardson-like" anomalous diffusion and reaction-diffusion equations, whose solution are known by numerical experiments to be asymptotically scale invariant; we obtain an analytical explanation of the numerically observed asymptotic scaling properties. We also apply our method to a different class of anomalous diffusion equations, relevant in optical lattices. The methods developed here can be applied to more general equations, as shown by their geometrical construction.
OPERADS AND JET MODULES
Authors: NIEPER-WISSKIRCHEN MARC A.
Published: December 2005

Let A be an algebra over an operad in a cocomplete closed symmetric monoidal category. We study the category of A-modules. We define certain symmetric product functors of such modules generalizing the tensor product of modules over commutative algebras, which we use to define the notion of a jet module. This in turn generalizes the notion of a jet module over a module over a classical commutative algebra. We are able to define Atiyah classes (i.e., obstructions to the existence of connections) in this generalized context. We use certain model structures on the category of A-modules to study the properties of these Atiyah classes.

The purpose of the paper is not to present any really deep theorem. It is more about the right concepts when dealing with modules over an algebra that is defined over an arbitrary operad, i.e., the aim is to show how to generalize various classical constructions, including modules of jets, the Atiyah class and the curvature, to the operadic context.

For convenience of the reader and for the purpose of defining the notations, the basic definitions of the theory of operads and model categories are included.
POVERTY AMONG SELF-EMPLOYED BUSINESSPEOPLE IN A RICH COUNTRY: A MISUNDERSTOOD AND DISTINCT REALITY
Authors: LAMBRECHT JOHAN , BEENS ELLEN
Published: December 2005

This article studies poverty among self-employed businesspeople in a rich country, Belgium. Existing research on self-employment income, compared with income of employees, has made clear that self-employed have a higher probability of falling in the lowest income groups and that there is a distinct self-employment effect. Our findings for Belgium show that approximately one quarter of those who are self-employed in their main occupation are living below the poverty line. We also confirm findings reported in the literature that income distribution among self-employed people is very unequal. It appears from our qualitative findings that poverty among self-employed businesspeople is something distinct from other forms of poverty. Several factors can cause self-employed businesspeople to end up in poverty. As a result, poverty is a multifaceted problem. Policy recommendations are formulated to prevent and combat poverty among self-employed businesspeople.
Heregulin-α and heregulin-β expression is linked to a COX-2-PGE2pathway in human gastric fibroblasts
Authors: Nagata Kazuhiro , Wada Ken , Tatsuguchi Atsushi , Futagami Seiji , Gudis Katya , Miyake Kazumasa , Tsukui Taku , Sakamoto Choitsu
Published: December 2005

We have previously shown heregulin (HRG)-α expression in human gastric fibroblasts and its stimulation of gastric epithelial cell growth. Although cyclooxygenase (COX)-2 has also been shown to stimulate growth factor production in these cells, the interaction between COX-2 and HRG remains unknown. Conditioned media (CM) from gastric fibroblasts incubated with PGE2or interleukin (IL)-1β, a well known COX-2 inducer, were analyzed for their effect on erbB3 tyrosine phosphorylation in MKN28 gastric epithelial cells. HRG protein expression in fibroblast lysates and CM was also examined by western blot. HRG-α and HRG-β mRNA expression in gastric fibroblasts and human gastric tissue was examined by real-time quantitative PCR. HRG and COX-2 expressions in surgical resections of human gastric ulcer tissue were examined immunohistochemically. CM from fibroblasts incubated with PGE2, or IL-1β, stimulated erbB3 phosphorylation in MKN28 cells. Preincubation of the fibroblasts with celecoxib, a selective COX-2 inhibitor, suppressed CM-induced erbB3 phosphorylation. This inhibition was reversed by exogenous PGE2. As with erbB3 phophorylation, IL-1β stimulated both HRG-α and HRG-β mRNA expression, as well as HRG release into gastric fibroblast CM. IL-1β-stimulated HRG expression and release were also inhibited by celecoxib, and exogenous PGE2restored this inhibitory effect, suggesting the activation of an IL-1β-COX-2-PGE2pathway that culminates in the release of HRG from fibroblasts. HRG-α and HRG-β mRNA levels were significantly higher in gastric ulcer tissue than in normal gastric mucosa. HRG immunoreactivity was found in interstitial cells of the gastric ulcer bed and coexpressed with COX-2. These results suggest that HRG might be a new member of the growth factor family involved in the COX-2-dependent ulcer repair process.
Dystroglycan receptor is involved in integrin activation in intestinal epithelia
Authors: Driss Adel , Charrier Laetitia , Yan Yutao , Nduati Vivienne , Sitaraman Shanthi , Merlin Didier
Published: December 2005

The dystroglycans (α-DG and β-DG), which play important roles in the formation of basement membranes, have been well studied in skeletal muscle and nerve, but their expression and localization in intestinal epithelial cells has not been previously investigated. Here, we demonstrated that the DG complex, composed of α-DG, β-DG, and utrophin, is specifically expressed in the basolateral membrane of the Caco-2-BBE monolayer. The DG complex coprecipitated with β1-integrin, suggesting a possible interaction among these proteins. In addition, we observed that activation of DG receptors by laminin-1 enhanced the interaction between β1-integrin and laminin-1, whereas activation of DG receptors by laminin-2 reduced the interaction between β1-integrin and laminin-2. Finally, we demonstrated that the intracellular COOH-terminal tail of β-DG and its binding to the DG binding domain of utrophin are crucial for the interactions between laminin-1/-2 and β1-integrin. Collectively, these novel results indicate that dystroglycans play important roles in the regulation of interactions between intestinal epithelial cells and the extracellular matrix.
β-Casomorphin-7 regulates the secretion and expression of gastrointestinal mucins through a μ-opioid pathway
Authors: Zoghbi Sandra , Trompette Aurélien , Claustre Jean , Homsi Mahmoud El , Garzón Javier , Jourdan Gérard , Scoazec Jean-Yves , Plaisancié Pascale
Published: December 2005

We have recently shown that β-casomorphin-7, a milk opioid peptide, strongly stimulates mucin secretion in the rat jejunum through a nervous pathway and opioid receptor activation. In this study, the hypothesis that β-casomorphin-7 may also act directly on intestinal goblet cells was investigated in vitro in rat and human intestinal mucin-producing cells (DHE and HT29-MTX) using quantitative and semiquantitative RT-PCR and ELISA. The presence of μ-opioid receptors was demonstrated in rat goblet cells in the upper half of the colonic crypt and in the two cell lines by immunohistochemistry and RT-PCR. In rat DHE cells, β-casomorphin-7 increased the expression of rat mucin (rMuc)2 and rMuc3 but not rMuc1, rMuc4, and rMuc5AC. This effect was time and dose dependent, with the maximum of increase in transcripts being noticed for a concentration of 10−4M after 2 h of stimulation for rMuc2 (225% of controls) and 4 h of stimulation for rMuc3 (208% of controls). Mucin secretion was maximally increased after 8 h of stimulation. Interestingly, these effects were prevented by pretreatment of the cells with the μ-opioid antagonist cyprodime. In human HT29-MTX cells, β-casomorphin-7 (10−4M) also increased MUC5AC mRNA levels (219% after 24 h of stimulation) and the secretion of this mucin (169% of controls). In conclusion, β-casomorphin-7 may contribute significantly to mucin production via a direct effect on intestinal goblet cells and the activation of μ-opioid receptors. Because intestinal mucins have a crucial mucosal protective function, dairy products containing β-casomorphin-7 may improve intestinal protection and could have dietary and health applications.
Probing lipid rafts with proximity imaging: actions of proatherogenic stimuli
Authors: Patschan Susann , Li Hong , Brodsky Sergey , Sullivan David , De Angelis Dino A. , Patschan Daniel , Goligorsky Michael S.
Published: December 2005

Glycosylphosphatidylinositol (GPI)-anchored proteins have been shown to cluster in microdomains enriched in glycosphingolipids and cholesterol and represent a relatively selective marker of lipid rafts. In recent years, several attempts have been made to use fluorescent probes to nondisruptively label these domains in living cells. Here, we have transfected endothelial cells with a GPI-anchored thermotolerant green fluorescent protein (ttGFP) to show colocalization of this fluoroprobe with another marker of lipid rafts, urokinase-type plasminogen activator receptor-1. ttGFP was used to quantify the cell surface area occupied by lipid rafts and to examine the effect of various proatherogenic signals on lipid rafts. Exposure of endothelial cells to asymmetric dimethylarginine and oxidized LDL (oxLDL), as well as oxidant stress, reduced the cell surface area occupied by lipid rafts. Next, the property of ttGFP to undergo a shift in absorbance depending on the clustering of these molecules was utilized to perform proximity imaging (PRIM). PRIM showed that nitric oxide (NO) increased the distance between GPI-anchored ttGFP molecules clustered in lipid-rich microdomains. This “unclustering” of GPI-anchored ttGFP was not reproduced by prooxidant signals and was due to reduction in membrane-cytoskeletal constraints on the lipid rafts. These findings suggested that two fundamentally different mechanisms modulate lipid rafts: 1) substance regulation of lipid rafts involving modification of cholesterol and sphingolipids and 2) structural regulation of lipid rafts through disruption of membrane-cytoskeletal interactions, switching off the spatial confinement of lipid rafts.
Influence of the adenosine A1receptor on blood pressure regulation and renin release
Authors: Brown Russell D. , Thorén Peter , Steege Andreas , Mrowka Ralf , Sällström Johan , Skøtt Ole , Fredholm Bertil B. , Persson A. Erik G.
Published: December 2005

The present study was performed to investigate the role of adenosine A1receptors in regulating blood pressure in conscious mice. Adenosine A1-receptor knockout (A1R−/−) mice and their wild-type (A1R+/+) littermates were placed on standardized normal-salt (NS), high-salt (HS), or salt-deficient (SD) diets for a minimum of 10 days before telemetric blood pressure and urinary excretion measurements in metabolic cages. On the NS diet, daytime and nighttime mean arterial blood pressure (MAP) was 7–10 mmHg higher in A1R−/− than in A1R+/+ mice. HS diet did not affect the MAP in A1R−/− mice, but the daytime and nighttime MAP of the A1R+/+ mice increased by ∼10 mmHg, to the same level as that in the A1R−/−. On the SD diet, day- and nighttime MAP decreased by ∼6 mmHg in both A1R−/− and A1R+/+ mice, although the MAP remained higher in A1R−/− than in A1R+/+ mice. Although plasma renin levels decreased with increased salt intake in both genotypes, the A1R−/− mice had an approximately twofold higher plasma renin concentration on all diets compared with A1R+/+ mice. Sodium excretion was elevated in the A1R−/− compared with the A1R+/+ mice on the NS diet. There was no difference in sodium excretion between the two genotypes on the HS diet. Even on the SD diet, A1R−/− mice had an increased sodium excretion compared with A1R+/+ mice. An abolished tubuloglomerular feedback response and reduced tubular reabsorption can account for the elevated salt excretion found in A1R−/− animals. The elevated plasma renin concentrations found in the A1R−/− mice could also result in increased blood pressure. Our results confirm that adenosine, acting through the adenosine A1receptor, plays an important role in regulating blood pressure, renin release, and sodium excretion.
Studies of oxytocin and vasopressin gene expression in the rat hypothalamus using exon- and intron-specific probes
Authors: Yue Chunmei , Mutsuga Noriko , Scordalakes Elka M. , Gainer Harold
Published: December 2005

To develop a comprehensive approach for the study of oxytocin (OT) and vasopressin (VP) gene expression in the rat hypothalamus, we first developed an intronic riboprobe to measure OT heteronuclear RNA (hnRNA) levels by in situ hybridization histochemistry (ISHH). Using this 84-bp riboprobe, directed against intron 2 of the OT gene, we demonstrate strong and specific signals in neurons confined to the supraoptic (SON) and paraventricular (PVN) nuclei of the rat hypothalamus. We used this new intronic OT probe, together with other well-established intronic and exonic OT and VP probes, to reevaluate OT and VP gene expression in the hypothalamus under two classical physiological conditions, acute osmotic stimulation, and lactation. We found that magnocellular neurons in 7- to 8-day lactating female rats exhibit increased OT but not VP hnRNA. Since VP mRNA is increased during lactation, this suggests that decreased VP mRNA degradation during lactation may be responsible for this change. In contrast, whereas there was the expected large increase in VP hnRNA after acute salt loading, there was no change in OT hnRNA, suggesting that acute hyperosmotic stimuli produce increased VP but not OT gene transcription. Hence, the use of both exon- and intron-specific probes, which distinguish the changes in hnRNA and mRNA levels, respectively, can provide insight into the relative roles of transcription and mRNA degradation processes in changes in gene expression evoked by physiological stimuli.
Constitutive pro- and anti-inflammatory cytokine and growth factor response to exercise in leukocytes
Authors: Zaldivar Frank , Wang-Rodriguez Jessica , Nemet Dan , Schwindt Christina , Galassetti Pietro , Mills Paul J. , Wilson Lori D. , Cooper Dan M.
Published: December 2005

Leukocytosis following exercise is a well-described phenomenon of stress/inflammatory activation in healthy humans. We hypothesized that, despite this increase in circulating inflammatory cells, exercise would paradoxically induce expression of both pro- and anti-inflammatory cytokines and growth factors within these cells. To test this hypothesis, 11 healthy adult men, 18–30 yr old, performed a 30-min bout of heavy cycling exercise; blood sampling was at baseline, end-exercise, and 60 min into recovery. The percentage of leukocytes positive for intracellular cytokines and growth factors and mean fluorescence intensity was obtained by flow cytometry. Proinflammatory cytokines (IL-1α, IL-2, IFN-γ, and TNF-α), a pleiotropic cytokine (IL-6), and anti-inflammatory cytokines and growth factors [IL-4, IL-10, growth hormone (GH), and IGF-I] were examined. Median fluorescence intensity was not affected by exercise; however, we found a number of significant changes ( P < 0.05 by mixed linear model and modified t-test) in the numbers of circulating cells positive for particular mediators. The pattern of expression reflected both pro- and anti-inflammatory functions. In T-helper lymphocytes, TNF-α, but also IL-6, and IL-4 were significantly increased. In monocytes, both IFN-γ and IL-4 increased. B-lymphocytes positive for GH and IGF-I increased significantly. GH-positive granulocytes also significantly increased. Collectively, these observations indicate that exercise primes an array of pro- and anti-inflammatory and growth factor expression within circulating leukocytes, perhaps preparing the organism to effectively respond to a variety of stressors imposed by exercise.
A Negative Carotid Plaque Area Test Is Superior to Other Noninvasive Atherosclerosis Studies for Reducing the Likelihood of Having Underlying Significant Coronary Artery Disease
Authors: Brook Robert D. , Bard Robert L. , Patel Smita , Rubenfire Melvyn , Clarke Nicholas S. , Kazerooni Ella A. , Wakefield Thomas W. , Henke Peter K. , Eagle Kim A.
Published: December 2005

Objective—

Coronary calcium score (CCS), carotid plaque area (CPA), intima-media thickness (IMT), and C-reactive protein (CRP) are independent predictors of cardiovascular prognosis. Although each test may enhance risk stratification, their comparative abilities to screen for underlying coronary stenoses in individual patients is less established.

Methods and Results—

Forty-two patients who had a 16-slice coronary computed tomography angiogram (CTA) performed were invited to have CPA, IMT, and CRP measured. CPA was defined as the sum of all the cross-sectional areas of each plaque >1 mm in diameter found in all carotid vessels bilaterally. CCS and the number plus degree of stenotic coronary arteries were determined by CTA. The presence of clinically significant coronary artery disease (CAD) was defined as the existence of any stenosis ≥50%. CTA identified clinically significant CAD in 43% of the patients. CPA >0 was more sensitive (72%) and specific (58%) than a CCS >0 (58% and 55%) for identifying CAD. A “clean” carotid artery (CPA=0) provides a superior negative predictive value (74%) and likelihood ratio of a negative test (0.48) than all other studies, in particular versus a CCS=0 (65% and 0.72). The areas under the receiver-operator curves for CPA and CCS in relation to any CAD were similar (0.640 versus 0.675). Carotid IMT and CRP performed poorly compared with CPA and CCS. For detecting CAD in only the left main or left anterior descending artery, the negative predictive value and likelihood ratio of a negative test remained superior for CPA (87% and 0.33) compared with CCS (80% and 0.56). In our population with a prevalence of these coronary lesions of 30%, the post-test probability in any patient with a negative CPA result is reduced to 10%.

Conclusion—

CPA determination is superior to CCS, IMT, and CRP in its ability to reduce the likelihood of clinically significant underlying CAD in patients of varying cardiac risk.
Effect of Vectors on Human Endothelial Cell Signal Transduction
Authors: Tan Peng H. , Xue Shao-An , Manunta Maria , Beutelspacher Sven C. , Fazekasova Henrieta , Shamsul Alam A.K.M. , McClure Myra O. , George Andrew J.T.
Published: December 2005

Objective—

Endothelium is an important target for gene therapy. We have investigated the effect of viral and nonviral vectors on the phenotype and function of endothelial cells (ECs) and developed methods to block any activation caused by these vectors.

Methods and Results—

Transduction of ECs with viral vectors, including adenovirus, lentiviruses, and Moloney murine leukemia virus, can induce a pro-inflammatory phenotype. This activation was reduced when nonviral vectors were used. We demonstrate that after transduction there is upregulation of dsRNA-triggered antiviral and PI3K/Akt signaling pathway. Blockade of the NFκB, PI3-K, or PKR signaling pathways all operated to inhibit partially virally induced activation, and inhibition of both PKR and PI3-K pathways totally blocked EC activation. Furthermore, inhibition of IFN-α/β in addition to PI3-K was effective at preventing EC activation.

Conclusions—

Viral vectors, although efficient at transducing ECs, result in their activation. Blockade of the signaling pathways involved in viral activation may be used to prevent such activation.
Bone Morphogenetic Protein Receptor-2 Signaling Promotes Pulmonary Arterial Endothelial Cell Survival
Authors: Teichert-Kuliszewska Krystyna , Kutryk Michael J.B. , Kuliszewski Michael A. , Karoubi Golnaz , Courtman David W. , Zucco Liana , Granton John , Stewart Duncan J.
Published: December 2005

Mutations in the bone morphogenetic protein (BMP) receptor-2 (BMPR2) have been found in patients with idiopathic pulmonary arterial hypertension (IPAH); however, the mechanistic link between loss of BMPR2 signaling and the development of pulmonary arterial hypertension is unclear. We hypothesized that, contrary to smooth muscle cells, this pathway promotes survival in pulmonary artery endothelial cells (ECs) and loss of BMPR2 signaling will predispose to EC apoptosis. ECs were treated with BMP-2 or BMP-7 (200 ng/mL) for 24 hours in regular or serum-free (SF) medium, with and without addition of tumor necrosis factor α, and apoptosis was assessed by flow cytometry (Annexin V), TUNEL, or caspase-3 activity. Treatment for 24 hours in SF medium increased apoptosis, and both BMP-2 and BMP-7 significantly reduced apoptosis in response to serum deprivation to levels not different from serum controls. Transfection with 5 μg of small interfering RNAs for BMPR2 produced specific gene silencing assessed by RT-PCR and Western blot analysis. BMPR2 gene silencing increased apoptosis almost 3-fold (
P
=0.0027), even in the presence of serum. Circulating endothelial progenitor cells (EPCs) isolated from normal subjects or patients with IPAH were differentiated in culture for 7 days and apoptosis was determined in the presence and absence of BMPs. BMP-2 reduced apoptosis induced by serum withdrawal in EPCs from normal subjects but not in EPCs isolated from patients with IPAH. These results support the hypothesis that loss-of-function mutations in BMPR2 could lead to increased pulmonary EC apoptosis, representing a possible initiating mechanism in the pathogenesis of pulmonary arterial hypertension.
Some Suggestions Towards Better Implementation of the United Nations Agreement on Straddling Fish Stocks and Highly Migratory Fish Stocks of 1995
Authors: Nandan Satya , Lodge Michael
Published: December 2005

In light of the upcoming Conference to review implementation of the 1995 United Nations Fish Stocks Agreement (UNFSA), this article: (1) reviews the main contribution of UNFSA to high seas fisheries governance; (2) notes issues that have arisen regarding implementation of UNFSA; and (3) suggests ways these might be addressed. Though the main problems pertain to inadequate implementation of the provisions of UNFSA, the article also addresses two areas that require further attention at the global level within the framework of UNFSA. The first involves discrete high seas fish stocks, particularly deep sea fish stocks and the impacts of destructive fishing practices. The second is the absence within RFMOs of a mechanism for allocation of allowable catches or levels that also takes conservation interests into consideration together with the economic and social interests of states. Specific recommendations for action are summarised in Annex II.
Addressing Regulatory Gaps in High Seas Fisheries
Authors: Molenaar Erik Jaap
Published: December 2005

Geographical and substantive regulatory gaps in high seas fisheries are serious weaknesses in the current global regime for the governance of marine capture fisheries. This article discusses recent developments on the establishment of new regional fisheries management organizations (RFMOs) and arrangements, identifies geographical gaps and examines scenarios to fill these. In view of the need for upgrading existing fishery bodies to ensure compatibility with the UN Fish Stocks Agreement, ample attention is devoted to the tool of performance assessments. Also examined in depth are the constraints for coastal States that wish to exercise their sovereign rights in relation to fishing practices that impact on sedentary species on their outer continental shelf. The discussion of the reform of the international legal regime for high seas fisheries is in particular devoted to discrete high seas fish stocks.
Ecosystem Considerations in Fisheries Management: Theory and Practice
Authors: Parsons Scott
Published: December 2005

This article examines recent developments with respect to the development and application of an ecosystem approach in marine fisheries management. A number of international fisheries legal instruments now include explicit references to ecosystem considerations. While there has been general agreement on the need to take ecosystem considerations into account, there is no clarity or consensus on how this can best be done. Various definitions of an ecosystem approach emphasise that the focus must be on managing the human activities, which are part of, and impact on, marine ecosystems. An ecosystem approach is neither inconsistent with, nor a replacement for, existing fisheries management approaches—it is not a panacea for the problems confronting world fisheries. Realistically, we can only move to an ecosystem approach incrementally, starting with more rigorous/cautious application and extension of single species methods. A key element of any ecosystem approach will likely be to set harvest rates for target species at even lower conservative levels than might be suggested by single species analysis. Fisheries management measures should also ensure the protection not only of target species, but also of non-target, associated or dependent species. Reducing the killing power of the world's fishing fleets is an essential component of ecosystem-based fisheries management.
Implementing Existing Tools: Turning Words Into Actions – Decision-Making Processes of Regional Fisheries Management Organisations (RFMOs)
Authors: McDorman Ted
Published: December 2005

This paper deals with decision-making processes within those regional fisheries management organisations (RFMOs) with the capacity to adopt management measures respecting either straddling or highly migratory fish stocks. The perception is that the decisions emanating from RFMOs are not achieving the goal of sustainable management of the fish stocks. Concerns raised in this regard are the perceived: non-adherence of RFMO decisions to science; lack of timeliness in making decisions; ability of RFMO members to avoid certain decisions; and adoption of management decisions that are not sufficiently rigorous. This contribution does not seek to evaluate the validity of the perception, rather it explores the manner in which RFMO conventions (the constitutive texts of RFMOs) deal with the decision-making process by looking at the trends within RFMOs, the challenges that exist and suggests ways to meet the challenges.
Economic Drivers of Illegal, Unreported and Unregulated (IUU) Fishing
Authors: Schmidt Carl-Christian
Published: December 2005

IUU fishing is an activity driven by economic factors, that is, the IUU fisher's expected net benefit. When expected net benefit is positive, the activity will continue somewhere, somehow. This underscores the importance of co-operation, international and regional, to ensure that the expected benefits from IUU activities are reduced by making sure potential loopholes are identified and fixed.OECD work on IUU fishing activities focuses on identifying new strategies that are based on the economics of the IUU activity. A number of key economic, institutional and social drivers have been identified, including excess fishing capacity, market value (price) of fish, the level of MCS (including VMS) operations and associated sanctions against IUU fishing, domestic management regimes, weak international legal frameworks and poor economic and social conditions in many parts of the fisheries world. These economic, institutional and social drivers underpin or weaken the profitability of IUU activities.In devising new strategies and measures to combat IUU fishing, it is essential to identify instruments that either reduce the expected income stream or alternatively increase the costs of the activity. To change the "expected benefit" of IUU fishing operations a number of actions can be taken. Among the promising avenues are efforts to step up monitoring and surveillance of IUU fishing activities. However, to be effective these also require that sufficiently restrictive levels of fines and penalties are in place. In the longer term, emphasis is also needed on more general development and educational activities that can provide fishers with alternative sources of income.