bluuebunny/crossref_metadata_2025 huggingface dataset:
Discovery of an RNA virus 3′→5′ exoribonuclease that is critically involved in coronavirus RNA synthesis
Authors: Minskaia Ekaterina , Hertzig Tobias , Gorbalenya Alexander E. , Campanacci Valérie , Cambillau Christian , Canard Bruno , Ziebuhr John
Published: March 2006

Replication of the giant RNA genome of severe acute respiratory syndrome (SARS) coronavirus (CoV) and synthesis of as many as eight subgenomic (sg) mRNAs are mediated by a viral replicase-transcriptase of outstanding complexity that includes an essential endoribonuclease activity. Here, we show that the CoV replicative machinery, unlike that of other RNA viruses, also uses an exoribonuclease (ExoN) activity, which is associated with nonstructural protein (nsp) 14. Bacterially expressed forms of SARS-CoV nsp14 were shown to act on both ssRNAs and dsRNAs in a 3′→5′ direction. The activity depended on residues that are conserved in the DEDD exonuclease superfamily. The protein did not hydrolyze DNA or ribose-2′-
O
-methylated RNA substrates and required divalent metal ions for activity. A range of 5′-labeled ssRNA substrates were processed to final products of ≈8–12 nucleotides. When part of dsRNA or in the presence of nonlabeled dsRNA, the 5′-labeled RNA substrates were processed to significantly smaller products, indicating that binding to dsRNA in cis or trans modulates the exonucleolytic activity of nsp14. Characterization of human CoV 229E ExoN active-site mutants revealed severe defects in viral RNA synthesis, and no viable virus could be recovered. Besides strongly reduced genome replication, specific defects in sg RNA synthesis, such as aberrant sizes of specific sg RNAs and changes in the molar ratios between individual sg RNA species, were observed. Taken together, the study identifies an RNA virus ExoN activity that is involved in the synthesis of multiple RNAs from the exceptionally large genomic RNA templates of CoVs.
Reconstitution of the transition from lamellipodium to filopodium in a membrane-free system
Authors: Haviv Lior , Brill-Karniely Yifat , Mahaffy Rachel , Backouche Frederic , Ben-Shaul Avinoam , Pollard Thomas D. , Bernheim-Groswasser Anne
Published: March 2006

The cellular cytoskeleton is a complex dynamical network that constantly remodels as cells divide and move. This reorganization process occurs not only at the cell membrane, but also in the cell interior (bulk). During locomotion, regulated actin assembly near the plasma membrane produces lamellipodia and filopodia. Therefore, most
in vitro
experiments explore phenomena taking place in the vicinity of a surface. To understand how the molecular machinery of a cell self-organizes in a more general way, we studied bulk polymerization of actin in the presence of actin-related protein 2/3 complex and a nucleation promoting factor as a model for actin assembly in the cell interior separate from membranes. Bulk polymerization of actin in the presence of the verprolin homology, cofilin homology, and acidic region, domain of Wiskott-Aldrich syndrome protein, and actin-related protein 2/3 complex results in spontaneous formation of diffuse aster-like structures. In the presence of fascin these asters transition into stars with bundles of actin filaments growing from the surface, similar to star-like structures recently observed
in vivo
. The transition from asters to stars depends on the ratio [fascin]/[G actin]. The polarity of the actin filaments during the transition is preserved, as in the transition from lamellipodia to filopodia. Capping protein inhibits star formation. Based on these experiments and kinetic Monte Carlo simulations, we propose a model for the spontaneous self-assembly of asters and their transition into stars. This mechanism may apply to the transition from lamellipodia to filopodia
in vivo
.
Proteasomes shape the repertoire of T cells participating in antigen-specific immune responses
Authors: Osterloh Philipp , Linkemann Kathrin , Tenzer Stefan , Rammensee Hans-Georg , Radsak Markus P. , Busch Dirk H. , Schild Hansjörg
Published: March 2006

Differences in the cleavage specificities of constitutive proteasomes and immunoproteasomes significantly affect the generation of MHC class I ligands and therefore the activation of CD8-positive T cells. Based on these findings, we investigated whether proteasomal specificity also influences CD8-positive T cells during thymic selection by peptides derived from self proteins. We find that one of the self peptides responsible for positive selection of ovalbumin-specific OT-1 T cells, which is derived from the f-actin capping protein (Cpα1), is efficiently generated only by immunoproteasomes. Furthermore, OT-1 mice backcrossed onto low molecular mass protein 7 (LMP7)-deficient mice show a 50% reduction of OT-1 cells. This deficiency is also observed after transfer of BM from OT-1 mice in LMP7-deficient mice and can be corrected by the injection of the Cpα1 peptide. Interestingly, WT and LMP7-deficient mice mount comparable immune responses to the ovalbumin-derived epitope SIINFEKL. However, their cytotoxic T lymphocytes (CTL) differ in the use of T cell receptor Vβ genes. CTL derived from WT mice use Vβ8 or Vβ5 (the latter is also used by OT-1 cells), whereas SIINFEKL-specific CTL from LMP7-deficient mice are exclusively Vβ8-positive. Taken together, our experiments provide strong evidence that proteasomal specificity shapes the repertoire of T cells participating in antigen-specific immune responses.
Translational repression is sufficient for gene silencing by bacterial small noncoding RNAs in the absence of mRNA destruction
Authors: Morita Teppei , Mochizuki Yukari , Aiba Hiroji
Published: March 2006

Stress-induced Hfq-binding small RNAs of
Escherichia coli
, SgrS and RyhB, down-regulate the expression of target mRNAs through base-pairing. These small RNAs form ribonucleoprotein complexes with Hfq and RNase E. The regulatory outcomes of the RNase E/Hfq/small RNA-containing ribonucleoprotein complex (sRNP) are rapid degradation of target mRNAs and translational inhibition. Here, we ask to what extent the sRNP-mediated mRNA destabilization contributes to the overall silencing of target genes by using strains in which the rapid degradation of mRNA no longer occurs. We demonstrate that translational repression occurs in the absence of sRNP-mediated mRNA destabilization. We conclude that translational repression is sufficient for gene silencing by sRNP. One possible physiological role of mRNA degradation mediated by sRNP is to rid the cell of translationally inactive mRNAs, making gene silencing irreversible.
Switch interactions control energy frustration and multiple flagellar filament structures
Authors: Kitao Akio , Yonekura Koji , Maki-Yonekura Saori , Samatey Fadel A. , Imada Katsumi , Namba Keiichi , Go Nobuhiro
Published: March 2006

Bacterial flagellar filament is a macromolecular assembly consisting of a single protein, flagellin. Bacterial swimming is controlled by the conformational transitions of this filament between left- and right-handed supercoils induced by the flagellar motor torque. We present a massive molecular dynamics simulation that was successful in constructing the atomic-level supercoil structures consistent with various experimental data and further in elucidating the detailed underlying molecular mechanisms of the polymorphic supercoiling. We have found that the following three types of interactions are keys to understanding the supercoiling mechanism. “Permanent” interactions are always maintained between subunits in the various supercoil structures. “Sliding” interactions are formed between variable hydrophilic or hydrophobic residue pairs, allowing intersubunit shear without large change in energy. The formation and breakage of “switch” interactions stabilize inter- and intrasubunit interactions, respectively. We conclude that polymorphic supercoiling is due to the energy frustration between them. The transition between supercoils is achieved by a “transform and relax” mechanism: the filament structure is geometrically transformed rapidly and then slowly relaxes to energetically metastable states by rearranging interactions.
Neurogenin1 is a determinant of zebrafish basal forebrain dopaminergic neurons and is regulated by the conserved zinc finger protein Tof/Fezl
Authors: Jeong Jae-Yeon , Einhorn Zev , Mercurio Sara , Lee Susie , Lau Billy , Mione Marina , Wilson Stephen W. , Guo Su
Published: March 2006

The development of vertebrate basal forebrain dopaminergic (DA) neurons requires the conserved zinc finger protein Too Few (Tof/Fezl) in zebrafish. However, how Tof/Fezl regulates the commitment and differentiation of these DA neurons is not known. Proneural genes encoding basic helix–loop–helix transcription factors regulate the development of multiple neuronal lineages, but their involvement in vertebrate DA neuron determination is unclear. Here we show that
neurogenin 1
(
ngn1
), a vertebrate proneural gene related to the
Drosophila
atonal
, is expressed in and required for specification of DA progenitor cells, and when overexpressed leads to supernumerary DA neurons in the forebrain of zebrafish. Overexpression of
ngn1
is also sufficient to induce tyrosine hydroxylase expression in addition to the pan-neuronal marker Hu in nonneural ectoderm. We further show that Tof/Fezl is required to establish basal forebrain
ngn1
-expressing DA progenitor domains. These findings identify Ngn1 as a determinant of brain DA neurons and provide insights into how Tof/Fezl regulates the development of these clinically important neuronal types.
Familial hypercatabolic hypoproteinemia caused by deficiency of the neonatal Fc receptor, FcRn, due to a mutant β2-microglobulin gene
Authors: Wani Manzoor A. , Haynes Lynn D. , Kim Jonghan , Bronson C. L. , Chaudhury Chaity , Mohanty Sudhasri , Waldmann Thomas A. , Robinson John M. , Anderson Clark L.
Published: March 2006

Two siblings, products of a consanguineous marriage, were markedly deficient in both albumin and IgG because of rapid degradation of these proteins, suggesting a lack of the neonatal Fc receptor, FcRn. FcRn is a heterodimeric receptor composed of a nonclassical MHC class I α-chain and β2-microglobulin (β2m) that binds two ligands, IgG and albumin, and extends the catabolic half-lives of both. Eight relatives of the siblings were moderately IgG-deficient. From sera archived for 35 years, we sequenced the two siblings’ genes for the heterodimeric FcRn. We found that, although the α-chain gene sequences of the siblings were normal, the β2m genes contained a single nucleotide transversion that would mutate a conserved alanine to proline at the midpoint of the signal sequence. Concentrations of soluble β2m and HLA in the siblings’ sera were <1% of normal. Transfection assays of β2m-deficient cultured cells with β2m cDNA indicated that the mutant β2m supported <20% of normal expression of β2m, MHC class I, and FcRn proteins. We concluded that a β2m gene mutation underlies the hypercatabolism and reduced serum levels of albumin and IgG in the two siblings with familial hypercatabolic hypoproteinemia. This experiment of nature affirms our hypothesis that FcRn binds IgG and albumin, salvages both from a degradative fate, and maintains their physiologic concentrations.
Control of petal shape and floral zygomorphy in
Lotus japonicus
Authors: Feng Xianzhong , Zhao Zhong , Tian Zhaoxia , Xu Shilei , Luo Yonghai , Cai Zhigang , Wang Yumei , Yang Jun , Wang Zheng , Weng Lin , Chen Jianghua , Zheng Leiying , Guo Xizhi , Luo Jianghong , Sato Shusei , Tabata Satoshi , Ma Wei , Cao Xiangling , Hu Xiaohe , Sun Chongrong , Luo Da
Published: March 2006

Zygomorphic flowers, with bilateral (dorsoventral) symmetry, are considered to have evolved several times independently in flowering plants. In
Antirrhinum majus
, floral dorsoventral symmetry depends on the activity of two TCP-box genes,
CYCLOIDEA
(
CYC
) and
DICHOTOMA
(
DICH
). To examine whether the same molecular mechanism of floral asymmetry operates in the distantly related
Rosid
clade of eudicots, in which asymmetric flowers are thought to have evolved independently, we investigated the function of a
CYC
homologue
LjCYC2
in a papilionoid legume,
Lotus japonicus
. We showed a role for
LjCYC2
in establishing dorsal identity by altering its expression in transgenic plants and analyzing its mutant allele
squared standard 1
(
squ1
). Furthermore, we identified a lateralizing factor,
Keeled wings in Lotus 1
(
Kew1
), which plays a key role in the control of lateral petal identity, and found
LjCYC2
interacted with
Kew1
, resulting in a double mutant that bore all petals with ventralized identity to some extents. Thus, we demonstrate that
CYC
homologues have been independently recruited as determinants of petal identities along the dorsoventral axis in two distant lineages of flowering plants, suggesting a common molecular origin for the mechanisms controlling floral zygomorphy.
Revised age estimates for the later Paleogene mammal faunas of Egypt and Oman
Authors: Seiffert Erik R.
Published: March 2006

The Jebel Qatrani Formation of northern Egypt has produced Afro-Arabia’s primary record of Paleogene mammalian evolution, including the world’s most complete remains of early anthropoid primates. Recent studies of Fayum mammals have assumed that the Jebel Qatrani Formation contains a significant Eocene component (≈150 of 340 m), and that most taxa from that succession are between 35.4 and 33.3 million years old (Ma), i.e., latest Eocene to earliest Oligocene in age. Reanalysis of the chronological evidence shared by later Paleogene strata exposed in Egypt and Oman (Taqah and Thaytiniti areas, Dhofar Province) reveals that this hypothesis is no longer tenable. Revised correlation of the Fayum and Dhofar magnetostratigraphies indicates that (i) only the lowest 48 m of the Jebel Qatrani Formation are likely to be Eocene in age; (ii) the youngest Fayum anthropoids, including well known species such asAegyptopithecus zeuxisandApidium phiomense, are probably between 30.2 and 29.5 Ma, ≈3–4 Ma younger than previously thought; (iii) oligopithecid anthropoids did not go extinct at the Eocene–Oligocene boundary but rather persisted for at least another 2.5 Ma; (iv) propliopithecid anthropoids first appear in the Fayum area at ≈31.5 Ma, long after the Eocene–Oligocene boundary; and (v) the youngest Fayum mammals may be only ≈1 Ma older than the 28- to 27-Ma mammals from Chilga, Ethiopia, and not 4–5 Ma older, as previously thought. Whatever gap exists in the Oligocene record of Afro-Arabian mammal evolution is now limited primarily to a poorly sampled 27- to 23-Ma window in the latest Oligocene.
The cholinergic antagonist α-bungarotoxin also binds and blocks a subset of GABA receptors
Authors: McCann Corey M. , Bracamontes John , Steinbach Joe Henry , Sanes Joshua R.
Published: March 2006

The polypeptide snake toxin α-bungarotoxin (BTX) has been used in hundreds of studies on the structure, function, and development of the neuromuscular junction because it binds tightly and specifically to the nicotinic acetylcholine receptors (nAChRs) at this synapse. We show here that BTX also binds to and blocks a subset of GABA
A
receptors (GABA
A
Rs) that contain the GABA
A
R β3 subunit. These results introduce a previously unrecognized tool for analysis of GABA
A
Rs but may complicate interpretation of some studies on neuronal nAChRs.
Alternative mutations of a positively selected residue elicit gain or loss of functionalities in enzyme evolution
Authors: Norrgård Malena A. , Ivarsson Ylva , Tars Kaspars , Mannervik Bengt
Published: March 2006

All molecular species in an organism are connected physically and functionally to other molecules. In evolving systems, it is not obvious to what extent functional properties of a protein can change to selective advantage and leave intact favorable traits previously acquired. This uncertainty has particular significance in the evolution of novel pathways for detoxication, because an organism challenged with new xenobiotics in the environment may still require biotransformation of previously encountered toxins. Positive selection has been proposed as an evolutionary mechanism for facile adaptive responses of proteins to changing conditions. Here, we show, by saturation mutagenesis, that mutations of a hypervariable residue in human glutathione transferase M2-2 can differentially change the enzyme’s substrate-activity profile with alternative substrates and, furthermore, enable or disable dissimilar chemical reactions. Crystal structures demonstrate that activity with epoxides is enabled through removal of steric hindrance from a methyl group, whereas activities with an orthoquinone and a nitroso donor are maintained in the variant enzymes. Given the diversity of cellular activities in which a single protein can be engaged, the selective transmutation of functional properties has general significance in molecular evolution.
Defining the BK channel domains required for β1-subunit modulation
Authors: Morrow John P. , Zakharov Sergey I. , Liu Guoxia , Yang Lin , Sok Andrea J. , Marx Steven O.
Published: March 2006

In a wide variety of cell types, including neurons and smooth muscle cells, activation of the large-conductance voltage- and Ca
2+
-activated K
+
(BK) channels causes transient membrane hyperpolarization, thereby regulating cellular excitability. Similar to other voltage-gated ion channels, BK channels, a tetramer of α-subunits, associate with auxiliary β-subunits in a tissue-specific manner, modifying the channel's gating properties. The BK β1-subunit, which is expressed in smooth muscle, increases the apparent Ca
2+
sensitivity (marked by a hyperpolarizing shift in the conductance–voltage relationship at a given Ca
2+
concentration), slows macroscopic activation and deactivation, and is required for channel activation by 17β-estradiol. The β1-subunit is essential for normal regulation of vascular smooth muscle contractility and blood pressure. Little is known, however, about the molecular mechanisms of β1-subunit modulation of α-subunits. Here we show that the β1-subunit's modulation of the Ca
2+
and 17β-estradiol sensitivities can be dissociated from its effects on gating kinetics by truncation of the α-subunit's extracellular N-terminal residues. The BK α-subunit N terminus interacts uniquely with the β1-subunit: β2 regulation of the α-subunit is unaltered by truncation of the N terminus. Although the functional interaction of α and β1 requires the N-terminal tail of α, the physical association requires the S1, S2, and S3 transmembrane helices of α.
Early-onset behavioral and synaptic deficits in a mouse model of Alzheimer's disease
Authors: Jacobsen J. Steven , Wu Chi-Cheng , Redwine Jeffrey M. , Comery Thomas A. , Arias Robert , Bowlby Mark , Martone Robert , Morrison John H. , Pangalos Menelas N. , Reinhart Peter H. , Bloom Floyd E.
Published: March 2006

Alzheimer's disease (AD) is a progressive neurodegenerative disorder for which numerous mouse models have been generated. In both AD patients and mouse models, there is increasing evidence that neuronal dysfunction occurs before the accumulation of β-amyloid (Aβ)-containing plaques and neurodegeneration. Characterization of the timing and nature of preplaque dysfunction is important for understanding the progression of this disease and to identify pathways and molecular targets for therapeutic intervention. Hence, we have examined the progression of dysfunction at the morphological, functional, and behavioral levels in the Tg2576 mouse model of AD. Our data show that decreased dendritic spine density, impaired long-term potentiation (LTP), and behavioral deficits occurred months before plaque deposition, which was first detectable at 18 months of age. We detected a decrease in spine density in the outer molecular layer of the dentate gyrus (DG) beginning as early as 4 months of age. Furthermore, by 5 months, there was a decline in LTP in the DG after perforant path stimulation and impairment in contextual fear conditioning. Moreover, an increase in the Aβ42/Aβ40 ratio was first observed at these early ages. However, total amyloid levels did not significantly increase until ≈18 months of age, at which time significant increases in reactive astrocytes and microglia could be observed. Overall, these data show that the perforant path input from the entorhinal cortex to the DG is compromised both structurally and functionally, and this pathology is manifested in memory defects long before significant plaque deposition.
Enhancement of long-term memory retention and short-term synaptic plasticity in cbl-b null mice
Authors: Tan Dong Ping , Liu Qi-Ying , Koshiya Naohiro , Gu Hua , Alkon Daniel
Published: March 2006

The
cbl-b
gene is a member of the
cbl
protooncogene family. It encodes a protein with multiple domains, which can interact with other proteins in a variety of signaling pathways. The functions of
cbl
family genes in the brain are unknown. In this report, we used genetic, immunohistochemical, behavioral, and electrophysiological approaches to study the role of cbl-b in learning and memory. Cbl-b null mice developed normally and had no abnormalities in their locomotor performance. In spatial learning and memory studies, cbl-b null and WT mice performed similarly during training. To test memory retention, two probe trials were used. cbl-b null mice performed slightly better 1 day after training. However, in the probe trial 45 days after training, the cbl-b null group showed significantly higher memory retention than WT mice, suggesting an enhancement of long-term memory. Using electrophysiological approaches, we found there was enhanced paired-pulse facilitation in the Schaffer Collateral-CA1 glutamatergic synapses of the cbl-b null mice. On the other hand, there was no difference in long-term potentiation between the two groups of mice. In summary, we provide evidence that (
i
) cbl-b protein is concentrated in the synaptic regions of CA1, CA3, and the dentate gyrus of the hippocampus; (
ii
) cbl-b null mice have enhanced long-term memory; and (
iii
) cbl-b null mice show an enhancement in short-term plasticity. These results indicate that cbl-b is a negative regulator of long-term memory, and its neuronal mechanism regulates synaptic transmission in the hippocampus.
High-sensitivity bacterial detection using biotin-tagged phage and quantum-dot nanocomplexes
Authors: Edgar Rotem , McKinstry Michael , Hwang Jeeseong , Oppenheim Amos B. , Fekete Richard A. , Giulian Gary , Merril Carl , Nagashima Kunio , Adhya Sankar
Published: March 2006

With current concerns of antibiotic-resistant bacteria and biodefense, it has become important to rapidly identify infectious bacteria. Traditional technologies involving isolation and amplification of the pathogenic bacteria are time-consuming. We report a rapid and simple method that combines
in vivo
biotinylation of engineered host-specific bacteriophage and conjugation of the phage to streptavidin-coated quantum dots. The method provides specific detection of as few as 10 bacterial cells per milliliter in experimental samples, with an ≈100-fold amplification of the signal over background in 1 h. We believe that the method can be applied to any bacteria susceptible to specific phages and would be particularly useful for detection of bacterial strains that are slow growing, e.g.,
Mycobacterium
, or are highly infectious, e.g.,
Bacillus anthracis
. The potential for simultaneous detection of different bacterial species in a single sample and applications in the study of phage biology are discussed.
Is Economics Performative? Option Theory and the Construction of Derivatives Markets
Authors: Mackenzie Donald
Published: March 2006

The thesis that economics is “performative” (Callon 1998) has provoked much interest but also some puzzlement and not a little confusion. The purpose of this article is to examine from the viewpoint of performativity one of the most successful areas of modern economics, the theory of options, and in so doing hopefully to clarify some of the issues at stake. To claim that economics is performative is to argue that itdoesthings, rather than simply describing (with greater or lesser degrees of accuracy) an external reality that is not affected by economics. Butwhatdoes economics do, and what are the effects of it doing what it does?

That the theory of options is an appropriate place around which to look for performativity is suggested by two roughly concurrent developments. Since the 1950s, the academic study of finance has been transformed from a low-status, primarily descriptive activity to a high-status, analytical, mathematical, Nobel-prize-winning enterprise. At the core of that enterprise is a theoretical account of options dating from the start of the 1970s. Around option theory there has developed a large array of sophisticated mathematical analyses of financial derivatives. (A “derivative” is a contract or security, such as an option, the value of which depends upon the price of another asset or upon the level of an index or interest rate.)
Conceptualizing Inequality and Risk
Authors: Persky Joseph , Bassett Gilbert W.
Published: March 2006

Economists and finance researchers have long recognized the “close relation between the measurement of inequality and the measurement of risk” (Breitmeyer et al., 2004). Economists today agree that a measure of income inequality must respect the Pigou-Dalton transfer principle, that is, inequality cannot increase with a transfer from a richer person to a poorer person. Finance researchers today agree that a measure of risk must respect the diversification principle, that is, risk cannot increase when portfolios are combined. Where did these convictions originate? While both principles were advocated early in their respective fields, they were not viewed as definitive until relatively recently. In both fields major empirical and theoretical efforts were mounted in support of various conceptualizations at odds with these two principles. For example, Robert Gibrat advocated the use of the variance of log income despite the fact it is inconsistent with the Pigou-Dalton principle. In finance, value at risk (VaR), although it can violate the diversification principle, was widely advocated. People supporting research programs at odds with Pigou-Dalton or the diversification principle, based those programs on ambitious empirical and theoretical claims about distributions. Such claims could have been right and are not a priori or logically false. The purpose of this paper is to review these “at odds” conceptualizations, the types of arguments advanced for their legitimacy, and the reasons they have been given up.
Myocardial Gene Expression of Angiogenic Factors in Human Chronic Ischemic Myocardium: Influence of Acute Ischemia/Cardioplegia and Reperfusion
Authors: WANG YONGZHONG , GABRIELSEN ANDERS , LAWLER PATRICK R. , PAULSSON‐BERNE GABRIELLE , STEINBRÜCHEL DANIEL A. , HANSSON GORAN K. , KASTRUP JENS
Published: March 2006

Objective: Angiogenic therapies in animals have demonstrated the development of new blood vessels within ischemic myocardium. However, results from clinical protein and gene angiogenic trials have been less impressive. The present study aimed to investigate the expression of angiogenic genes in human chronic ischemic myocardium and the influence of acute ischemia/cardioplegia and reperfusion on their expression.

Methods: Myocardial biopsies were taken from chronic ischemic and nonischemic myocardium in 15 patients with stable angina pectoris during coronary bypass surgery. Tissue samples were evaluated by oligonucleotide microarray and quantitative real‐time PCR for the expression of angiogenic factors.

Results: There was identical baseline expression of VEGF‐A and VEGF‐C mRNA in chronic ischemic myocardium compared with nonischemic myocardium. Reperfusion increased the gene expression of VEGF‐A and VEGF‐C mRNA both in nonischemic and ischemic myocardium. VEGF‐A protein was detected mainly in the extracellular matrix around the cardiomyocytes in ischemic myocardium.

Conclusion: These data suggest that the nonconclusive VEGF gene therapy trials chronic coronary artery disease was not due to a preexisting upregulation of VEGF in chronic ischemic myocardium. There might be room for further therapeutic angiogenesis in chronic ischemic myocardium.
Coronary Vasomotor Reactivity to Endothelin‐1 in the Prediabetic Metabolic Syndrome
Authors: KNUDSON JARROD D. , ROGERS PAUL A. , DINCER Ü. Deniz , BRATZ IAN N. , ARAIZA ALBERTO G. , DICK GREGORY M. , TUNE JOHNATHAN D.
Published: March 2006

Objective:The purpose of the present investigation was to test the hypothesis that coronary vasoconstrictor responses to endothelin‐1 are augmented in the prediabetic metabolic syndrome.

Methods:ELISA was used to measure plasma endothelin‐1 and intracoronary endothelin‐1 dose‐response experiments were conducted in vivo on normal control and high‐fat‐fed prediabetic dogs. Additionally, isolated left circumflex (LCX) coronary arteries and arterioles (< 160 μ m) were used for in vitro functional studies and molecular analyses (quantitative real‐time PCR and Western blotting).

Results:Plasma endothelin‐1 concentrations were not different between control and prediabetic dogs. Coronary vasoconstriction to endothelin‐1 was similar in control and prediabetic dogs, both in vivo and in isolated arterioles. Nonetheless, real‐time PCR analysis revealed significant decreases in ETA receptor transcript levels in LCX coronary arteries and arterioles. Also, Western blotting revealed a significant decrease in ETA receptor protein in LCX coronary arteries.

Conclusions:The findings of the present investigation indicate that although ETA receptor‐signaling is sensitized by induction of the metabolic syndrome, endothelin‐mediated coronary vasoconstriction does not significantly contribute to coronary dysfunction at this early stage of prediabetes.
Mast Cell Degranulation Alters Lymphatic Contractile Activity Through Action of Histamine
Authors: PLAKU KELLY J. , VON DER WEID PIERRE‐YVES
Published: March 2006

Objective: Mast cells reside in most tissues and in close association with blood vessels and nerves, areas where lymphatic vessels are also present. Mast cells and lymphatic vessels are two important players in the development of the inflammatory process. This study was designed to examine the effects of mast cell degranulation on the contractile activity of mesenteric lymphatic vessels.

Methods: Lymphatic vessel contractile activity was assessed in vitro by video microscopy of the mesentery of cow's milk‐sensitized guinea pigs upon application of β‐lactoglobulin and compared to the response measured in sham animals.

Results: Application of 5–10 μM β‐lactoglobulin increased lymphatic vessel constriction frequency and decreased constriction amplitude (n = 12). This effect was not seen in sham‐treated animals (n = 16) and was not due to an increased number of mast cells in the mesentery of the milk‐sensitized animals, as revealed by histological examination. Two known mast cell‐derived mediators, histamine and thromboxane A2, via stable mimetic U46619 also altered lymphatic pumping in a similar manner, but only pretreatment with the histamine H1 receptor antagonist pyrilamine (1 μM) could reduce the β‐lactoglobulin‐induced response. The thromboxane A2 receptor antagonist, SQ 29548, and the 5‐lipoxygenase inhibitor, caffeic acid, were without significant effect.

Conclusion: In the in vitro mesenteric preparation, mast cell degranulation altered lymphatic contractile activity via the release of a mediator suggested to be histamine and the subsequent activation of H1 receptors. This action could potentially interfere with the expected ability of lymphatic vessels to reduce edema during inflammation.
Perivascular Cells Along Venules Upregulate NG2 Expression During Microvascular Remodeling
Authors: MURFEE WALTER L. , REHORN MICHAEL R. , PEIRCE SHAYN M. , SKALAK THOMAS C.
Published: March 2006

Objective: Recently the authors have shown that neuron–glial antigen 2 (NG2) is expressed by perivascular cells along arterioles and capillaries, but not along venules in quiescent rat mesenteric microvascular networks. To investigate how the spatial distribution of this proteoglycan changes during microvascular remodeling, the objective of this study was to characterize the expression of NG2 in adult rat mesenteric microvascular networks undergoing active remodeling.

Methods: The distribution of NG2 expression was evaluated in adult rat mesenteric microvascular networks. Tissues were harvested from 250 g, female, Sprague‐Dawley rats at 1, 3, and 5 days poststimulation and double immunolabeled for NG2 and CD31 (endothelial cell marker).

Results: After 1 day, NG2 expression was observed along 27 ± 11% of network draining venules (14–55 μm) and after 3 days, 59 ± 10% of draining venules (13–59 μm) stained positive for the proteoglycan. By 5 days poststimulation, the percentage of network draining venules (18–59 μm) staining positive for NG2 returned to 18 ± 7%, indicating a downregulation of the proteoglycan toward quiescent levels along larger‐sized venules.

Conclusions: The results suggest that NG2 proteoglycan expression is transiently upregulated along venules during microvascular remodeling, implicating NG2 as a marker of activated venules.
Language skills, learning to read and reading intervention
Authors: Snowling Margaret J. , Hulme Charles
Published: March 2006

The paper outlines a framework for the development of reading that shows it is heavily dependent upon spoken language processes. Within this view, reading difficulties can follow from difficulties with speech processing (decoding problems) or from broader language processing impairments
(comprehension problems). The paper describes the literacy development of children at high-risk of reading failure and shows how their reading outcome depends on the interaction of the phonological and language skills they bring to the task of reading. Findings have implications for the development
of theoretically motivated reading interventions. The evaluation of such interventions is described.
Learning to read and learning to comprehend
Authors: Nation Kate , Angell Philip
Published: March 2006

This paper reviews recent experimental findings that inform our understanding of the development of reading comprehension. Studies investigating children who have specific difficulties with reading comprehension provide considerable information concerning the process involved in successful
reading comprehension. This literature highlights aspects of reading comprehension skill that cannot be readily accommodated by the 'searchlights' model—the theoretical model framework adopted by the National Literacy Strategy. We conclude that comprehension depends on a very complex
set of processes, many of which are shared with language comprehension more generally. Finally, implications for the teaching of reading comprehension are discussed.
Mixed integer programming for a swine manure handling system in the Jiulong River watershed
Authors: Liu Jianchang , Zhang Luoping , Zeng Yue , Chen Nengwang , Chen Weicai , Li Yongyu , Hong Huasheng
Published: March 2006

Swine finishing produces a large contribution of manure to nearby surface water and ground water in Jiulong upstream watershed, south Fujian Province, China. It is urgent to find a comprehensive, cost-effective way, not only to solve the manure pollution problem, but also to utilize the nutrients of manure for local farming. Gekou, a small hoggery village in the dense swine-farming core area of the upstream watershed, was selected as the study area. Mixed integer programming models based on uncertain interval numbers were employed to generate optimal whole farm plans for specialized hoggery. Emphasis was placed on discerning the most profitable ways to formulate hog feed rations, manure collection, manure storage, and manure application to achieve the maximum profit and the minimum pollution emission. Analyses were concentrated on ammonia emissions, excess total nitrogen and excess total phosphorus from manure operations, not only as nutrients applied to croplands, but also as pollutants to be minimized in compliance with environmental criteria. Three different hog feed rations, two alternative ways of collecting hog manure, and two alternative storage methods were combined with five alternatives for field application of manure to provide different combinations of hog feeding and manure-handling to be evaluated in the mixed integer programming models. Results indicated tradeoffs between economic goals and environmental goals, the latter being achieved only at some expense to farm net returns. The kaleyard and fishpond are recommended alternatives for field application of manure compared to three other alternatives.
Study of nitrification behavior in aerated biofilters using oyster shell carrier
Authors: Xiong Xiaojing , Ye Zhilong
Published: March 2006

The effect of the pH level on the dissociative behavior of calcium ion from oyster shell was evaluated in batch experiments. The results indicated that when the initial pH changed from 3.0 to 10.0, equilibrium pH possibly maintained at about 8.0. Nitrification behaviors at various pH and NH4+-N loads were investigated simultaneously in two aerated biofilters packed with oyster shell and plastic balls, respectively. The results showed that when the influent NH4+-N concentrations varied from 15 to 60 mg l− 1, 63.6 to 97.5 percent of NH4+−N could be removed by the oyster shell biofilter, but only 13.3 to 29.0% could be removed by the plastic ball biofilter at the influent pH of 5.3∼ 5.7. Furthermore, due to the sufficient alkalinity supply in oyster shell biofilter, the effluent pH could be maintained above 6.5, indicating that oyster shell shows greater buffer capacity.
Cumulative effects assessment of bay ecosystem: Xiamen's Western Sea, a case study
Authors: Yang Xiai , Xue Xiongzhi , Shen Shawn S.
Published: March 2006

Considering the deficiency of conventional environment a impacts assessment to protect bay ecosystems from unfavourable impacts of multiple human activities over the years, this paper discusses an effective approach framework to examine addictive or interactive impacts arising from the collective multiple activities of the past. There are three stages of the cumulative effects assessment process: 1) systematically selecting indicators of the ecosystem in question, 2) choosing the quantified or semi-quantified methods to assess indicators of changes, and 3) assessing the past contributions of the activities to the changes.

In a case study of Xiamen's Western Sea in China, the indicators were constructed according to their sensitivities to environmental stress and classified into three categories: physical, chemical and biological indicators. The Geography Information System and Pearson correlation analysis were applied to assess changes of the physical and chemical indicators. The case study showed that most of the indicators of Xiamen's Western Sea ecosystem have been changed greatly in the past five decades, especially in shoreline, sea area, water quality, community construction of phytoplankton and benthos, and mangrove forests. Coastal and dike construction and terrestrial pollutant input are the main causes of the changes.
Research advances in nutrient runoff on sloping land in watersheds
Authors: Li Yong , Wang Chao , Tang Hongliang
Published: March 2006

High nitrate and phosphorus concentrations in runoff resulting from sloping lands (especially agricultural sloping lands) have direct consequences on the aquatic environment through eutrophication of surface water. This paper details the transfer mechanism of nutrients in soil on sloping lands influenced by natural and artificial factors. Results showed that the rainfall intensity had a small influence on nutrient concentrations in runoff, but a significant influence on the runoff flow on sloping lands. The slope length influenced the nutrient loss by soil erosion on areas that receive rainfall. The slope gradient influenced the nutrient loss by runoff flux and velocity on sloping land. As the slope gradient decreased, the nutrient loss decreased because of the increase in infiltration. The soil texture, porosity, and water content influenced the motion of soil water and the transfer and form of nutrients in soil, through oxidation and deoxidation. Vegetative coverage influenced the infiltration coefficient of rainwater into subsurface soil, and thus influenced the runoff flow velocity. Therefore, different sloping lands need to be managed in different ways. To better carry out best management practices in watersheds, a new management based on sloping lands needs to be further studied, including changing fertilization quantity, improving fertilization technology, adjusting vegetation coverage, and studying cultivation systems on different sloping lands within a watershed.
Physiological responses of submerged macrophytes to dibutyl phthalate (dbp) exposure
Authors: Li J. H. , Guo H. Y. , Mu J. L. , Wang X. R. , Yin D. Q.
Published: March 2006

Physiological and biochemical perturbations of some submerged macrophytes, including Ceratophyllum demersum, Vallisneria spiralis and Potamogeton maackianus, were investigated following 25-day exposures to different concentrations of dibutyl phthalate. Plants were assayed for malon-diadehyde, soluble carbohydrate, chlorophyll, protein and glutathione. Results showed that contents of malon-diadehyde in submerged macrophytes decreased irregularly with increase in dibutyl phthalate. Contents of soluble carbohydrate in the Vallisneria spiralis had negative correlations with the concentrations of dibutyl phthalate and contents of soluble carbohydrate in the Potamogeton maackianus had positive correlation with increase in dibutyl phthalate. The contents of chlorophyll in Vallisneria spiralis changed irregularly and those of Ceratophyllum demersum and Potamogeton maackianus were higher than the control. The contents of protein and glutathione in these submerged macrophytes were less than the control. Contents of glutathione in Vallisneria spiralis had significantly negative correlations with increasing concentrations of dibutyl phthalate. Content of protein and glutathione might be considered as sensitive indexes of early damage to submerged macrophytes by dibutyl phthalate.
A proposal for the application of integrated coastal management for institutional arrangements in Xiamen
Authors: Zhang Liyu , Xue Xiongzhi , Fang Qinhua , Shen Shawn S.
Published: March 2006

Integrated Coastal Management (ICM) is a feasible approach to address coastal issues, including resource use conflicts, ecological environments and management issues. An institutional arrangement is a precondition for the fulfillment of management functions. Therefore, a scientific institutional arrangement must be established as soon as possible for more effective implementation of ICM. In this paper, theories on ICM institutional arrangements were analyzed. In addition, characteristics and lessons learned domestically and internationally from the ICM institutional arrangements were summarized. Finally, based on the issues encountered in the first Xiamen ICM implementation, as well as on the major existing problems faced in Xiamen's coast, establishing a new ICM institutional arrangement for Xiamen was proposed.
Nitrogen and phosphorus loads from agricultural non-point sources based on grid-based geographic information systems (GIS)
Authors: Hong Huasheng , Huang Jinliang
Published: March 2006

The overall objective of this study is to quantify the contributions of nitrogen and phosphorus loads in surface water and identify the critical source areas in a medium-sized scale watershed in the southeast of China. The method of integrating grid-based Geographic Information Systems with empirical models is applied. The curve numbers method is used to estimate surface runoff. The Universal Soil Loss Equation is employed to predict the soil loss in the Jiulong River watershed. Empirical methods for calculating nitrogen and phosphorus discharge are further utilized to calculate loads based on the spatial analysis of a grid system. Spatial distribution of nitrogen and phosphorus loads in terms of sub-watersheds, land-use type and counties/districts in the Jiulong River watershed is represented. Various contributions and sources of nitrogen and phosphorus loads in surface water for each county or district in the Jiulong River watershed are calculated and evaluated. Study results show that excessive fertilizer use and livestock breeding contribute significant nitrogen and phosphorus loads for many counties. The contribution of livestock breeding to these nutrient loads for the Zhangzhou and Xinluo districts were 40 to 47% and 51 to 62%, respectively. Critical source areas and major contributors of non-point source nutrients are identified. The quantitative data of nutrient loads from agricultural non-point sources in the Jiulong River watershed estimated from the study could provide the scientific basis for management and control of nutrients and pollution.
Induction of ethoxyresorufin-O-deethylase (EROD) activity in the liver of black porgy (Acanthopagrus schlegeli) exposed to benzo(a)pyrene
Authors: Wang Xinhong , Mu Jingli , Wang Shuhong , Lin Jianqing , Hong Huasheng
Published: March 2006

This paper studied the induction kinetics of the enzyme 7-ethoxyresorufin O-deethylase in the liver of the marine fish, Acanthopagrus schlegeli following the exposure to benzo (a)pyrene for up to 14 days at concentrations of 0.5, 1.0, 2.0,5.0 μg l−1. The results demonstrated a dose-response relationship between hepatic enzyme activities induction and benzo(a)pyrene concentration. Hepatic enzyme activities were significantly induced by the second day with exposure to the lower concentrations of benzo(a)pyrene (0.5 μg l−1 and 1.0 μ g l−1), and at 12 hours of exposure for the higher concentrations (2.0 l−1 and 5.0 μ g l−1). After 7 days depuration, the activities of the enzyme of fish returned to the control level. This indicated that while benzo(a)pyrene has an effect on the hepatic enzyme activity, the fish can eliminate a major part of BaP metabolites.
An HIV intervention: The work of the Convictus Eesti group in Estonian prisons
Authors: Kalantar Tamara , Alijev Latsin
Published: March 2006

Convictus Eesti is a non‐government organisation (NGO) operating in Estonia that receives some funding from another Convictus branch based in Sweden. Its main activities include extensive needle exchange programmes and provision of prevention information for injecting drug users and their families. The organisation also supports the government in the collection of accurate statistics concerning injecting drug use, such as the health status, socio‐economic circumstances and ethnicity of this particular group, and offers anonymous HIV testing, condom distribution and counselling in their office in Tallinn. In November 2004, Convictus Eesti received confirmation that it will get partial funding for its Day Centre plans in Tallinn from the Estonian Government. The Convictus organisation successfully co‐operates with many other organisations that work actively in penitentiary systems, for example Estonian Network of PLWH(Estonia), DIA ‐ LOGS (Latvia), MONAR (Poland), Blagodiynost (Ukraine), ENDIPP, CEEHRN.
There are nine prisons in Estonia and approximately 400 prisoners out of 4700 are HIV+. Considering that HIV testing is voluntary, this number might be three or even four times greater. The average age of infected prisoners is 20‐25 years. Every week, between four and five new HIV cases are discovered in Estonian prisons, and this increase is
attributed to the lack of knowledge about hygiene and the danger of HIV and sexually transmitted diseases among prisoners. In addition, the Ministry of Justice states that 70‐
80% of prisoners use drugs at least once during their sentence.