bluuebunny/crossref_metadata_2025 huggingface dataset:
Serpins: Finely Balanced Conformational Traps
Authors: Pike Robert N. , Bottomley Stephen P. , Irving James A. , Bird Phillip I. , Whisstock James C.
Published: September 2003

Serine protease (serpins) play very important roles in the maintenance of various physiologically important systems. As knowledge of the workings of proteins of this family grows, new understanding is gained of the mechanisms by which they inhibit target proteases, using conformational changes for which the structure of serpins is uniquely adapted. This finely balanced system is utilized to healthy benefit in the control of serpin function by modulators, arguably the most striking examples of which occur in the control of proteolytic cascades, such as the coagulation system. Serpins also play very important intracellular roles: one example is the protection of immune cells from their own cytotoxic proteases. The finely balanced serpin mechanism also means that it is prone to disastrous consequences if mutations should occur in vital positions in the serpin structure. Many examples of disease‐associated mutations have been shown, which has the dual effect of highlighting how important these molecules are in the maintenance of health and the fine balance that must be maintained in order to preserve their active, inhibitory conformation.
Isolation and Characterization of a Porin‐Like Outer Membrane Protein from Xanthomonas campestris pv. campestris
Authors: Wang Lingyun , Zheng Ying , Zhang Xujia
Published: September 2003

Xanthomonas campestris pv. campestris, a plant‐associated pathogenic bacterium, is the causal agent of foliar spots and blights in crucifers. The major outer membrane protein, Omp37, of 37 kDa, has been identified, purified to homogeneity, and its characterization has also been carried out. Native Omp37 behaved as a trimer, as revealed by gel filtration and SDS‐PAGE. FTIR measurements revealed a high β‐structure content. The pore‐forming ability of the purified Omp37 was studied by the liposome swelling assay. Omp37, to our knowledge, is the first porin that has been isolated from Xanthomonas . This study clearly demonstrates that Omp37 is related to the family of trimeric bacterial porins.
A Resurgent Phoenix‐‐A Hypothesis for the Origin of Meiosis
Authors: Li Wei , Zheng Guo‐Chang
Published: September 2003

The origin and evolution of sex is a great puzzle in biology, and meiosis is the core of sex. Here, we propose a new hypothesis that meiosis may have evolved by blending features of two responses that cells have to deal with double‐strand‐DNA breaks, recombinational repair and apoptosis. This hypothesis can explain some unsolved problems and is in agreement with some known molecular mechanisms, cytological phenomena, and the fossil records. Furthermore, it can predict some testable features of meiosis.
Selection of Peptide Ligands Binding to Fibroblast Growth Factor Receptor 1
Authors: Fan Hongkuan , Duan Yanfen , Zhou Hui , Li Wei , Li Fei , Guo Lili , Roeske Roger W.
Published: September 2003

Inappropriate expression of fibroblast growth factors (FGFs) or activation of FGF receptors (FGFRs) could contribute to several human angiogenic pathologies. In an attempt to design antagonists of FGF, we developed a screening procedure for identifying peptide ligands binding to FGFR1. To retain the natural conformation of FGFR1 during screening, we expressed recombinant FGFR1 on the surface of Sf9 insect cells. A 6‐mer phage display peptide library was then screened on the cell surface and a group of hydrophobic peptide sequences were identified. Further experiments demonstrated that the phages displaying these sequences can specifically bind to FGFR1. The docking analysis suggests that the peptide ValTyrMetSerProPhe can specifically bind to the hydrophobic surface of FGFR1. The synthetic peptide Ac‐ValTyrMetSerProPhe‐NH 2 can inhibit mitogenic activity of aFGF and has the potential to become a therapeutic agent as an aFGF antagonist.
Gene and Cell Therapy for Heart Disease
Authors: Graham Regina M. , Bishopric Nanette H. , Webster Keith A.
Published: September 2003

Heart disease is the most common cause of morbidity and mortality in Western society and the incidence is projected to increase significantly over the next few decades as our population ages. Heart failure occurs when the heart is unable to pump blood at a rate to commensurate with tissue metabolic requirements and represents the end stage of a variety of pathological conditions. Causes of heart failure include ischemia, hypertension, coronary artery disease, and idiopathic dilated cardiomyopathy. Hypertension and ischemia both cause infarction with loss of function and a consequent contractile deficit that promotes ventricular remodeling. Remodeling results in dramatic alterations in the size, shape, and composition of the walls and chambers of the heart and can have both positive and negative effects on function. In 30‐40% of patients with heart failure, left ventricular systolic function is relatively unaffected while diastolic dysfunction predominates. Recent progress in our understanding of the molecular and cellular bases of heart disease has provided new therapeutic targets and led to novel approaches including the delivery of proteins, genes, and cells to replace defective or deficient components and restore function to the diseased heart. This review focuses on three such strategies that are currently under development: (a) gene transfer to modulate contractility, (b) therapeutic angiogenesis for the treatment of ischemia, and (c) embryonic and adult stem cell transfer to replace damaged myocardium.
Identification of Modified Proteins by Mass Spectrometry
Authors: Sickmann Albert , Mreyen Marcus , Meyer Helmut E.
Published: September 2003

Because it is obvious that high‐throughput genomics do not lead to a molecular description or even a prediction of protein function, modern techniques for protein analysis become increasingly more important. Sequence analysis of proteins and peptides is not limited to the elucidation of the primary structure of a protein. The analysis of posttranslational modifications is an important task of protein chemistry in proteome research. Increased sensitivity in mass spectrometry as a result of more efficient ionization techniques and better detection systems has allowed the stepwise reduction of protein quantity for analysis. Protein spots of 2D‐PAGE separated samples are now sufficient for an unequivocal identification of a protein by mass spectrometry. In addition to protein identification, a closer look at posttranslational modifications is now also possible. It is assumed that modifications such as phosphorylation or glycosylation exist on every second protein and that they are important for the protein function.
Tocotrienols Inhibit Human Glutathione S‐Transferase P1‐1
Authors: van Haaften Rachel I. M. , Haenen Guido R. M. M. , Evelo Chris T. A. , Bast Aalt
Published: September 2003

Tocopherols and tocotrienols are food ingredients that are believed to have a positive effect on health. The most studied property of both groups of compounds is their antioxidant action. Previously, we found that tocopherols and diverse tocopherol derivatives can inhibit the activity of human glutathione S‐transferase P1‐1 (GST P1‐1). In this study we found that GST P1‐1 is also inhibited, in a concentration‐dependent manner, by α‐ and γ‐tocotrienol. The concentration giving 50% inhibition of GST P1‐1 is 1.8 ±0.1 μM for α‐tocotrienol and 0.7 ±0.1 μM for γ‐tocotrienol. This inhibition of GST P1‐1 is noncompetitive with respect to both substrates CDNB and GSH. We also examined the 3D structure of GST P1‐1 for a possible tocopherol/tocotrienol binding site. The enzyme contains a very hydrophobic pit‐like structure where the phytyl tail of tocopherols and tocotrienols could fit in. Binding of tocopherol and tocotrienol to this hydrophobic region might lead to bending of the 3D structure. In this way tocopherols and tocotrienols can inhibit the activity of the enzyme; this inhibition can have far‐reaching implications for humans.
Down‐Regulation of Organic Anion Transporter 2 mRNA Expression by Nitric Oxide in Primary Cultured Rat Hepatocytes
Authors: Cha Seok Ho , Kim Hong Pyo , Jung Nam‐Hee , Lee Woon Ki , Kim Ju Young , Cha Young‐Nam
Published: September 2003

Role of nitric oxide (NO) 1 on the expression of organic anion transporter 2 (OAT2) located in sinusoidal domain of hepatocytes has been investigated. Effect of NO generated in vivo in rat and delivered in vitro to hepatocytes was determined. Lipopolysaccharide (LPS) and spermine NONOate (SPER/NO) were selected as the NO donors for in vivo and in vitro experiments, respectively. Constitutive basal expression of rOAT2 mRNA was detected in the normal rat liver and the level of its expression was decreased by intraperitoneal administration of LPS. This LPS‐induced decrement did not occur when aminoguanidine (AG), an inhibitor of iNOS, was co‐administered with LPS. The expression of rOAT2 mRNA was detected in hepatocytes, but not in the nonparenchymal cells. In the primary cultured hepatocytes obtained from normal rats (normal hepatocytes), a time‐dependent decline of rOAT2 mRNA expression was observed, but not in the hepatocytes obtained from rats pretreated with gadolinium chloride (GdCl 3, Gd‐hepatocytes), an inhibitor of Kupffer cell activation. The decline of rOAT2 mRNA expression observed in the normal hepatocytes was enhanced by LPS treatment, but not in the Gd‐hepatocytes. The LPS‐dependent enhancement in the decline of rOAT2 mRNA expression did not occur when the normal hepatocytes were treated with AG or actinomycin D. When the Gd‐hepatocytes were treated with SPER/NO, an NO donor, the rOAT2 mRNA expression declined markedly. Combined, our results suggest that rOAT2 mRNA expression in hepatocytes is down‐regulated by NO at least at the transcriptional step.
Unification for the Expression of the Monophenolase and Diphenolase Activities of Tyrosinase
Authors: Fenoll L. G. , Rodríguez‐López J. N. , García‐Molina F. , García‐Cánovas F. , Tudela J.
Published: September 2003

In order to unify and generalize, we define the International Units used to express the monophenolase and diphenolase activity of mushroom tyrosinase acting on different monophenol/diphenol pairs and establish a quantitative relation. Similarly, the activity units to express tyrosinase activity proposed by suppliers are discussed and compared with the above International Units. Lastly, we study the relation between International Units of diphenolase activity and of monophenolase activity for other biological sources of tyrosinase.
In Vivo Studies on Mouse Erythrocytes Linked to Transferrin
Authors: Pérez M. Teresa , García‐Pérez Ana Isabel , Pinilla Montserrat , Sancho Pilar
Published: September 2003

Transferrin (Tf), a plasma protein with numerous, highly specific receptors in proliferating and differentiating cells was already discussed as a targeting ligand for drugs and liposomes in previous studies. In this paper, we deal with erythrocytes linked to Tf as possible physiological targeting carrier systems for delivering anticancer drugs. For that purpose we have used glutaraldehyde (0.1%) as a coupling agent between Tf and erythrocytes. The highest amount of Tf linked to erythrocytes turned out to be 0.76 ±0.13 μg Tf/10 6 cells, while reaching 65% of cell recovery. After 13 days, the Tf‐erythrocytes hemolysis reached 50%, with transferrin still coupled to erythrocytes. The in vivo kinetic behaviour of intravenously injected 51 Cr‐Tf‐erythrocytes showed a reduced half‐life to hours as compared to days of controls. However, a considerable percentage of Tf‐erythrocytes (close to 20%) remained circulating for a relatively long period (around 2 days), which made possible the specific targeting by these carrier systems. In vivo biodistribution studies indicated that 51 Cr‐Tf‐erythrocytes rapidly accumulated in the different studied organs (liver, spleen, lungs, kidneys, femur‐tibia, and heart), suggesting a selective removal of Tf‐erythrocytes by the cells of the mononuclear phagocytic system present mainly in liver and spleen. On the other hand, Tf‐erythrocytes showed a poor targeting of heart tissue, therefore a reduced cardiac toxicity should be expected after administration of erythrocyte‐encapsulated drugs. The presence of Tf‐erythrocytes in femur‐tibia and spleen could be related to the Tf‐specific binding to the hematopoietic cells containing Tf receptors. The final results of this study encourage additional research on Tf‐erythrocyte to investigate the relationship between transferrin‐mediated targeting by carrier erythrocytes and uptake of different erythrocyte‐encapsulated drugs. Consequently, the current study showed possible use of these carriers as a potential therapeutic tool for drug targeting in animal models with alterations affecting mononuclear phagocytic system or carcinomas of various origins whose cells show elevated number of Tf receptors.
The Complementary Membranes Forming the Blood‐Brain Barrier
Authors: Hawkins Richard A. , Peterson Darryl R. , Viña Juan R.
Published: September 2003

Brain capillary endothelial cells form the blood‐brain barrier. They are connected by extensive tight junctions, and are polarized into luminal (blood‐facing) and abluminal (brain‐facing) plasma membrane domains. The polar distribution of transport proteins allows for active regulation of brain extracellular fluid. Experiments on isolated membrane vesicles from capillary endothelial cells of bovine brain demonstrated the polar arrangement of amino acid and glucose transporters, and the utility of such arrangements have been proposed. For instance, passive carriers for glutamine and glutamate have been found only in the luminal membrane of blood‐brain barrier cells, while Na‐dependent secondary active transporters are at the abluminal membrane. This organization could promote the net removal of nitrogen‐rich amino acids from brain, and account for the low level of glutamate penetration into the central nervous system. Furthermore, the presence of a γ‐glutamyl cycle at the luminal membrane and Na‐dependent amino acid transporters at the abluminal membrane may serve to modulate movement of amino acids from blood‐to‐brain. Passive carriers facilitate amino acid transport into brain. However, activation of the γ‐glutamyl cycle by increased plasma amino acids is expected to generate oxoproline within the blood‐brain barrier. Oxoproline stimulates secondary active amino acid transporters (Systems A and B o,+ ) at the abluminal membrane, thereby reducing net influx of amino acids to brain. Finally, passive glucose transporters are present in both the luminal and abluminal membranes of the blood‐brain barrier. Interestingly, a high affinity Na‐dependent glucose carrier has been described only in the abluminal membrane. This raises the question whether glucose entry may be regulated to some extent. Immunoblotting studies suggest more than one type of passive glucose transporter exist in the blood‐brain barrier, each with an asymmetrical distribution. In conclusion, it is now clear that the blood‐brain barrier participates in the active regulation of brain extracellular fluid, and that the diverse functions of each plasma membrane domain contributes to these regulatory functions.
Nitric Oxide and Mycobacterium leprae Pathogenicity
Authors: Visca Paolo , Fabozzi Giulia , Milani Mario , Bolognesi Martino , Ascenzi Paolo
Published: September 2003

Leprosy is an old, still dreaded infectious disease caused by the obligate intracellular bacterium Mycobacterium leprae . During the infectious process, M. leprae is faced with the host macrophagic environment, where the oxidative stress and NO release, combined with low pH, low pO 2, and high pCO 2, contribute to limit the growth of the bacilli. Comparative genomics has unraveled massive gene decay in M. leprae, linking the strictly parasitic lifestyle with the reductive genome evolution. Compared with Mycobacterium tuberculosis and Mycobacterium bovis, the leprosy bacillus has lost most of the genes involved in the detoxification of reactive oxygen and nitrogen species. The very low reactivity of the unique truncated hemoglobin retained by M. leprae could account for the susceptibility of this exceptionally slow‐growing microbe to NO.
Phenomenological Perspectives on the Folding of β/α‐Barrel Domains Through the Modular Formation and Assembly of Smaller Structural Elements
Authors: Maiti Sankar , Luthra‐Guptasarma Manni , Guptasarma Purnananda
Published: September 2003

The β/α‐barrel motif was once considered to be a single protein domain. In recent years, however, it has been shown to consist of smaller substructures displaying the ability to fold autonomously. Here we review the current status of experimental findings concerning the motif's folding behavior in the light of what is currently known about (a) the relative rates of formation of helices and sheets in proteins, in general, and (b) the peculiarities of topology and architecture of the motif, in particular, to develop a detailed phenomenological understanding of how β/α‐barrels might form through the modular folding and assembly of substructures.
Heparin and Heparan Sulfate Biosynthesis
Authors: Sugahara Kazuyuki , Kitagawa Hiroshi
Published: September 2003

Heparan sulfate is one of the most informationally rich biopolymers in Nature. Its simple sugar backbone is variously modified to different degrees depending on the cellular conditions. Thus, it matures to have an enormously complicated structure, which most likely exhibits a considerable number of unique overlapping sequences with peculiar sulfation profiles. Such sequences are recognized by specific complementary proteins, which form a huge group of “heparin‐binding proteins,” and the sugar sequences in turn support unique functions of the respective proteins through specific interactions. The heparan sulfate sequences are not directly encoded by genes, but are created by elaborate biosynthetic mechanisms, which ensure the generation of these indispensable sequences. In heparan sulfate biosynthesis, the tetrasaccharide sequence (GlcA‐Gal‐Gal‐Xyl‐), designated the protein linkage region, is first assembled on a specific Ser residue at the glycosaminoglycan attachment site of a core protein. A heparan sulfate chain is then polymerized on this fragment by alternate additions of GlcNAc and GlcA through the actions of glycosyltransferases with overlapping specificities encoded by the tumor suppressor EXT family genes. Then follow various modifications by N ‐deacetylation and N ‐sulfation of glucosamine, C5‐epimerization of GlcA and multiple O ‐sulfations of the component sugars. Recent studies have achieved purification of several, and molecular cloning of most, of the enzymes responsible for these reactions. Some of these enzymes are bifunctional. The availability of cDNA probes has facilitated elucidation of the crystal structures for two of the biosynthetic enzymes, demonstration of their intracellular location, and their occurrence in complexes to achieve rapid and efficient synthesis of complex sugar sequences. Genomic structure and transcript analysis have shown the existence of multiple isoforms for most of the sulfotransferases. Many aspects of the heparan sulfate biosynthetic scheme are shared by the structural analog heparin, which is synthesized in mast cells and some other mammalian cells and is several‐fold higher degree of polymerization and more extensive modification than heparan sulfate.
Mammalian Hyaluronan Synthases
Authors: Itano Naoki , Kimata Koji
Published: September 2003

Three mammalian hyaluronan (HA) synthase genes, HAS1, HAS2, and HAS3, have been cloned and expressed, allowing the mechanisms for regulation of HA biosynthesis and function to be studied. The hyaluronan synthase (HAS) isoforms differ in kinetic characteristics and product size. The expression of each HAS isoform is controlled in a different fashion when mammalian cells are stimulated by various cytokines and the expression patterns are both spatially and temporally regulated during embryonic development. The existence of three different HAS isoforms with different characteristics implies that the broad range of biological and physiological roles performed by HA are regulated by controlling the activities and expression of the HAS isoforms. This review focuses on recent findings on the regulatory mechanisms for controlling HA biosynthesis and provides new insights into the enzymic basis for the functional regulation of HA.
Clonidine Displacement from Type 1 Imidazoline Receptor by p ‐Aminobenzamidine, the Prototype of Trypsin‐Like Serine Protease Inhibitors
Authors: Pallottini Valentina , Marino Maria , Ascenzi Paolo
Published: September 2003

p ‐Aminobenzamidine inhibits competitively the catalytic activity of enzymes that recognize preferentially the L ‐arginyl side chain and related structures. Notably, p ‐aminobenzamidine is considered as the prototype of trypsin‐like serine protease inhibitors. Furthermore, p ‐aminobenzamidine inhibits the catalytic activity of nitric oxide synthase type I and type II as well as copper amine oxidase. Taking into account the structural similarity between p ‐aminobenzamidine, agmatine (the putative endogenous ligand of the membrane type 1 imidazoline receptor (I 1 ‐R)), and N ‐amidino‐2‐hydroxypyrrolidine (the product of agmatine oxidation by copper amine oxidase), the [ 3 H]clonidine displacement from I 1 ‐R in rat heart membranes by p ‐aminobenzamidine was investigated. p ‐Aminobenzamidine is as effective as agmatine and N ‐amidino‐2‐hydroxypyrrolidine and more effective than the antihypertensive drug clonidine to displace [ 3 H]clonidine from I 1 ‐R. Therefore, trypsin‐like serine protease inhibitors structurally related to p ‐aminobenzamidine should be administrated under careful control.
Inhibitors of Apoptosis Proteins in Injury and Disease
Authors: Lotocki George , Keane Robert W.
Published: September 2003

The inhibitor of apoptosis (IAP) gene family prevents cell death by binding to and inhibiting caspases. In addition to negatively regulating apoptosis, IAPs bind to signaling intermediates and receptors, and participate in diverse cellular functions. Here, we describe the physiological functions of IAPs and their participation in injury and disease processes.
Structural Features of Proteins Responsible for Resistance of Tryptophan Residues to Nitrosylation
Authors: Suntsova Tatiana P. , Beda Nataliya V. , Nedospasov Andrei A.
Published: September 2003

It is known that potentially reactive groups of the protein molecule may be most efficiently nitros(yl)ated only when located within hydrophobic globules or built into the membrane. N 1 ‐nitrosotryptophan (NOW) is a stable product of nitrosation in vitro. However, the NOW fraction in proteins is small in ordinary proteins. It suggests the existence of unknown mechanisms preventing the accumulation of NOW. Here we show that these mechanisms are underlain by the protein structure. Analysis of protein structure databases to explore the atomic surroundings of tryptophan residues revealed preferential selection of certain surroundings. N(E) atoms of tryptophan residues, which are the targets for nitrosation, have usually polar and nucleophilic groups in their environment. Residues of Asp, Glu, Cys, His, and Met act as catalysts of denitrosation (internal denitrosilase). We found that short peptides with the same residues possessed denitrosilase activity even in solution. This selection might explain both the resistance of tryptophan residues in proteins to nitrosation and the mechanisms of chemical communication by means of reversible nitrosation of proteins.
The Energetics of Ion Distribution: The Origin of the Resting Electric Potential of Cells
Authors: Veech Richard L. , Kashiwaya Yoshihiro , Gates Denise N. , King M. Todd , Clarke Kieran
Published: September 2003

The relation between the energies of ion movement and ATP hydrolysis is unknown in tissues with widely varying electric potentials. Consequently, we measured the concentration of the nine major inorganic ions in the extra‐ and intracellular phases in heart, liver, and red cells with resting electrical potentials, E N, of ‐86, ‐28, and ‐6 mV, respectively, under six different physiological conditions. We calculated the Nernst electric potential and the energy of ion movement between the phases. We found that the energy of ATP hydrolysis was essentially constant, between ‐54 and ‐58 kJ/mol, in all tissues and conditions. In contrast, as E N decreased, the energies of the Na + and K + gradients decreased, with slopes approximating their valence. The difference between the energies of Na + and K + gradients remained constant at 17 kJ/mol, which is approximately one third of the energy of ATP hydrolysis, demonstrating near‐equilibrium of the Na +/K + ATPase in all tissues under all conditions. All cations, except K +, were pumped out of cells and all anions, except Cl ‐ in liver and red cell, were pumped into cells. We conclude that the energy of ATP was expressed in Na +/K + ATPase and its linked inorganic ion transporters to create a Gibbs‐Donnan near‐equilibrium system, an inherent part of which was the electric potential.
Effects of Epidermal Growth Factor and Linoleic Acid on Lipid Contents in Human Intestinal C2BBe1 Cells
Authors: Liang Chiu‐Fang , Chao Jane C. ‐J. , Hwang Shiaw‐Min , Tsai Ya‐Hui
Published: September 2003

Epidermal growth factor (EGF) was reported to regulate triacyl glycerol synthesis in various cells. Linoleic acid and its metabolites were thought to modulate the signal transduction of growth factors. This study determined whether linoleic acid regulated the effect of EGF on lipid contents in human intestinal C2BBe1 cells. Confluent cells were incubated with serum‐free medium (control), EGF (45 ng/mL), linoleic acid (42 μg/mL), or combined EGF (45 ng/mL) and linoleic acid (42 μg/mL) for 48 h. The results showed EGF and linoleic acid significantly increased intracellular cholesterol and triglyceride levels compared with the control and combined groups. EGF was a more potent stimulator for triacyl glycerol synthesis in C2BBe1 cells than linoleic acid. However, intracellular cholesterol and triglyceride levels did not differ between the control and combined groups. The secretion of cholesterol and triglyceride into the medium by C2BBe1 cells did not differ among four groups. Both EGF and linoleic acid strongly stimulated the expression of EGF receptor mRNA in C2BBe1 cells at 48 h compared with the control and combined groups. Therefore, EGF and linoleic acid increased triacyl glycerol synthesis in C2BBe1 cells through stimulating the expression of EGF receptor mRNA. The effect of EGF and linoleic acid on this lipogenesis was reversed in the presence of both EGF and linoleic acid by downregulating the expression of EGF receptor mRNA.
RNA‐Binding Proteins That Target the Androgen Receptor mRNA
Authors: Wilce Jackie A. , Leedman Peter J. , Wilce Matthew C. J.
Published: September 2003

Recent efforts to elucidate mechanisms of posttranscriptional gene regulation have resulted in the description of both cis ‐ and trans ‐acting factors which affect the stability and translational efficiency of specific mRNAs. Here we summarise some of the concepts in this field, with particular attention to recently discovered protein/RNA interactions involving the human androgen receptor mRNA. Such systems are of interest for their potential as targets for the modulation of protein production.
Degradation of mRNA in Escherichia coli
Authors: Jain Chaitanya
Published: September 2003

Degradation of messenger RNAs (mRNAs) is a universal process that occurs in every cell and has important implications for nucleotide metabolism and gene expression. One organism in which mRNA degradation has been thoroughly studied is the bacterium Escherichia coli ( E. coli ). In this review I describe what is presently known about the different processes involved in the conversion of mRNAs from high molecular weight species to mononucleotides in E. coli . The ribonucleases and accessory factors involved in mRNA degradation, and features on mRNAs that make them resistant or sensitive to degradation will also be described. At the conclusion of this review, some of the anticipated directions of future research on this topic will be discussed.
Insect Inhibitors of Metalloproteinases
Authors: Vilcinskas Andreas , Wedde Marianne
Published: September 2003

Two types of peptidic metalloproteinase inhibitors have recently been identified in insects. A homologue of vertebrate tissue inhibitors of metalloproteinases (TIMPs) was found in the fruitfly Drosophila melanogaster which may contributes to regulation of a corresponding matrix metalloproteinase (MMP). The first member of MMPs from insects which shares similarity with vertebrate MMPs has also been cloned and characterized from Drosophila, suggesting conserved evolution of both MMPs and TIMPs. The first insect inhibitor of metalloproteinases (IMPI), which was identified in larvae of the greater wax moth, Galleria mellonella, shares no sequence similarity with known vertebrate or invertebrate proteins and represents the first non‐TIMP‐like inhibitor of metalloproteinases reported to date. In contrast to TIMPs, the IMPI is not active against MMPs but inhibits microbial metalloproteinases such as bacterial thermolysin. Insects may recognize such toxic metalloproteinases associated with invading pathogens by particular peptidic fragments that result from their nonregulated activity within the hemolymph. Metalloproteinases induce expression of the IMPI along with other antimicrobial proteins in course of humoral immune response of G. mellonella, thereby mediating regulation of metalloproteinase activity released within the hemolymph and inhibition of pathogen development as well.
Des(1–3)IGF‐1 Treatment Normalizes Type 1 IGF Receptor and Phospho‐Akt (Thr 308) Immunoreactivityin Predegenerative Retina of Diabetic Rats
Authors: Kummer A. , Pulford B. E. , Ishii D. N. , Seigel G. M.
Published: September 2003

Little is known about interventions that may prevent
predegenerative changes in the diabetic retina. This study
tested the hypothesis that immediate, systemic treatment
with an insulin‐like growth factor (IGF)‐1 analog can prevent
abnormal accumulations of type 1 IGF receptor, and
phospho‐Akt (Thr 308) immunoreactivity in predegenerative
retinas of streptozotocin (STZ) diabetic rats. Type 1
IGF receptor immunoreactivity increased approximately
3‐fold in both inner nuclear layer (INL) and ganglion
cell layer (GCL) in retinas from STZ rats versus nondiabetic
controls. Phospho‐Akt (Thr 308) immunoreactivity
increased 5‐fold in GCL and 8‐fold in INL of STZ rat retinas.
In all cases, immunoreactive cells were significantly
reduced in STZ des(1–3)IGF‐1–treated versus STZ rats.
Preliminary results suggested that vascular endothelial
growth factor (VEGF) levels may also be reduced. Hyperglycemia/
failure of weight gain in diabetic rats continued
despite systemic des(1–3)IGF‐1. These data show
that an IGF‐1 analog can prevent early retinal biochemical
abnormalities implicated in the progression of diabetic
retinopathy, despite ongoing hyperglycemia.
β‐Cell Expansion for Therapeutic Compensation of Insulin Resistance in Type 2 Diabetes
Authors: Efrat Shimon
Published: September 2003

Insulin resistance is the primary cause of type 2 diabetes.
However, if compensated by increased insulin production,
insulin resistance by itself does not lead to overt
disease. Type 2 diabetes develops when this compensation
is insufficient, due to defects in β‐cell function and in regulation
of the β‐cell mass. β‐Cell transplantation, as well
as approaches that replenish or preserve the endogenous
β‐cell mass, may facilitate the treatment of type 2 diabetes
in patients requiring exogenous insulin.
A Lipoprotein Lipase–Promoting Agent, NO‐1886, Improves Glucose and Lipid Metabolism in High Fat, High Sucrose–Fed New Zealand White Rabbits
Authors: Yin Weidong , Yuan Zhonghua , Tsutsumi Kazuhiko , Xie Yuxiang , Zhang Qiuju , Wang Zongbao , fu Guoxiang , Long Guang , Yang Yongzong
Published: September 2003

The synthetic compound NO‐1886 is a lipoprotein
lipase activator that lowers plasma triglycerides and
elevates high‐density lipoprotein cholesterol (HDL‐C).
Recently, the authors found that NO‐1886 also had an action
of reducing plasma glucose in high‐fat/high‐sucrose
diet–induced diabetic rabbits. In the current study, we
investigated the effects of NO‐1886 on insulin resistance
and β‐cell function in rabbits. Our results showed that
high‐fat/high‐sucrose feeding increased plasma triglyceride,
free fatty acid (FFA), and glucose levels and decreased
HDL‐C level. This diet also induced insulin resistance
and impairment of acute insulin response to
glucose loading. Supplementing 1% NO‐1886 into the
high‐fat/high‐sucrose diet resulted in decreased plasma
triglyceride, FFA, and glucose levels and increased HDL‐C
level. The authors also found a clear increased glucose
clearance and a protected acute insulin response
to intravenous glucose loading by NO‐1886 supplementation.
These data suggest that NO‐1886 suppresses
the elevation of blood glucose in rabbits induced by feeding a high‐fat/high‐sucrose diet, probably through
controlling lipid metabolism and improving insulin
resistance.
Evasion of Phagocytosis through Cooperation between Two Ligand-binding Regions in Streptococcus pyogenes M Protein
Authors: Carlsson Fredric , Berggård Karin , Stålhammar-Carlemalm Margaretha , Lindahl Gunnar
Published: September 2003

The M protein of Streptococcus pyogenes is a major bacterial virulence factor that confers resistance to phagocytosis. To analyze how M protein allows evasion of phagocytosis, we used the M22 protein, which has features typical of many M proteins and has two well-characterized regions binding human plasma proteins: the hypervariable NH2-terminal region binds C4b-binding protein (C4BP), which inhibits the classical pathway of complement activation; and an adjacent semivariable region binds IgA-Fc. Characterization of chromosomal S. pyogenes mutants demonstrated that each of the ligand-binding regions contributed to phagocytosis resistance, which could be fully explained as cooperation between the two regions. Deposition of complement on S. pyogenes occurred almost exclusively via the classical pathway, even under nonimmune conditions, but was down-regulated by bacteria-bound C4BP, providing an explanation for the ability of bound C4BP to inhibit phagocytosis. Different opsonizing antisera shared the ability to block binding of both C4BP and IgA, suggesting that the two regions in M22 play important roles also under immune conditions, as targets for protective antibodies. These data indicate that M22 and similar M proteins confer resistance to phagocytosis through ability to bind two components of the human immune system.
MyD88 Primes Macrophages for Full-Scale Activation by Interferon-γ yet Mediates Few Responses to Mycobacterium tuberculosis
Authors: Shi Shuangping , Nathan Carl , Schnappinger Dirk , Drenkow Jörg , Fuortes Michele , Block Ellen , Ding Aihao , Gingeras Thomas R. , Schoolnik Gary , Akira Shizuo , Takeda Kiyoshi , Ehrt Sabine
Published: September 2003

Macrophages are activated from a resting state by a combination of cytokines and microbial products. Microbes are often sensed through Toll-like receptors signaling through MyD88. We used large-scale microarrays in multiple replicate experiments followed by stringent statistical analysis to compare gene expression in wild-type (WT) and MyD88−/− macrophages. We confirmed key results by quantitative reverse transcription polymerase chain reaction, Western blot, and enzyme-linked immunosorbent assay. Surprisingly, many genes, such as inducible nitric oxide synthase, IRG-1, IP-10, MIG, RANTES, and interleukin 6 were induced by interferon (IFN)-γ from 5- to 100-fold less extensively in MyD88−/− macrophages than in WT macrophages. Thus, widespread, full-scale activation of macrophages by IFN-γ requires MyD88. Analysis of the mechanism revealed that MyD88 mediates a process of self-priming by which resting macrophages produce a low level of tumor necrosis factor. This and other factors lead to basal activation of nuclear factor κB, which synergizes with IFN-γ for gene induction. In contrast, infection by live, virulent Mycobacterium tuberculosis (Mtb) activated macrophages largely through MyD88-independent pathways, and macrophages did not need MyD88 to kill Mtb in vitro. Thus, MyD88 plays a dynamic role in resting macrophages that supports IFN-γ–dependent activation, whereas macrophages can respond to a complex microbial stimulus, the tubercle bacillus, chiefly by other routes.
Lipopolysaccharide Interaction with Cell Surface Toll-like Receptor 4-MD-2
Authors: Akashi Sachiko , Saitoh Shin-ichiroh , Wakabayashi Yasutaka , Kikuchi Takane , Takamura Noriaki , Nagai Yoshinori , Kusumoto Yutaka , Fukase Koichi , Kusumoto Shoichi , Adachi Yoshiyuki , Kosugi Atsushi , Miyake Kensuke
Published: September 2003

Toll-like receptors (TLRs) are innate recognition molecules for microbial products, but their direct interactions with corresponding ligands remain unclarified. LPS, a membrane constituent of gram-negative bacteria, is the best-studied TLR ligand and is recognized by TLR4 and MD-2, a molecule associated with the extracellular domain of TLR4. Although TLR4-MD-2 recognizes LPS, little is known about the physical interaction between LPS and TLR4-MD-2. Here, we demonstrate cell surface LPS–TLR4-MD-2 complexes. CD14 greatly enhances the formation of LPS–TLR4-MD-2 complexes, but is not coprecipitated with LPS–TLR4-MD-2 complexes, suggesting a role for CD14 in LPS loading onto TLR4-MD-2 but not in the interaction itself between LPS and TLR4-MD-2. A tentative dissociation constant (Kd) for LPS–TLR4-MD-2 complexes was ∼3 nM, which is ∼10–20 times lower than the reported Kd for LPS–MD-2 or LPS–CD14. The presence of detergent disrupts LPS interaction with CD14 but not with TLR4-MD-2. E5531, a lipid A antagonist developed for therapeutic intervention of endotoxin shock, blocks LPS interaction with TLR4-MD-2 at a concentration 100 times lower than that required for blocking LPS interaction with CD14. These results reveal direct LPS interaction with cell surface TLR4-MD-2 that is distinct from that with MD-2 or CD14.
Emotional intelligence and transformational leadership in retailing
Authors: Duckett Hilary , Macfarlane Elspeth
Published: September 2003

This study examines the relationship between emotional intelligence (EQ) and transformational leadership in the context of a UK‐based retailing organisation and examines whether a relationship exists between store manager performance and EQ profiles. It identifies a discrepancy between the organisation’s idealized leader success criteria and the average profiles derived from its current cohort of store managers. The results show a strong connection between the theory of EQ and transformational leadership: however, differences between the idealised and actual EQ scores were mainly located in transactional capabilities. The study also questions the requirement for transformational leader qualities at all stages of an organisation’s life cycle.
Preventing Legionellosis: is your action plan completed?
Authors: Brundrett G.W.
Published: September 2003

Concentrates on the fact that britain has had an unusually large proportion of cases of Legionnaires’ Disease. Reminds employers of obligations of buildings legialtion from the Health and Safety at Work Act and The Code of practice on Prevention of Legionellosis (which came into force on 10 April 1990). Reports on the history of Legionellosis, the infection route, actions for employers to take to prevent infection. Indicates that outbreaks of the disease in a company is traumatic regarding staff relations and personal tragedy. It can also be expensive as insurance companies no longer look on outbreaks as “Acts of God”.
Literacy project development resources
Authors: Agee Jim
Published: September 2003

Literacy is a global problem that concerns librarians and educators. This article provides resources for individuals who want to develop literacy projects. It comprises many descriptions of literacy organizations, grant sources, and book aid groups, both global and local. Many resources are available for literacy project developers. Those in this article will stimulate project developer’s thinking and planning regardless of country.
“Change your life?” – a project for adult learners run by Gosport Library, Hampshire
Authors: Denyer Julie , Gill Angela , Turner Jan
Published: September 2003

The “Change your life?” event was the culmination of a lifelong learning project throughout Hampshire libraries that had begun at the Gosport branch. Describes the context in which the idea for the promotional event was conceived. Discusses the methodology and planning undertaken and particularly assesses the role of partnership working. Evaluates the impact of “Change your life?” and identifies the areas with room for improvement and lessons to be learned for future projects.
The changing image of Birmingham libraries: marketing strategy into action
Authors: Gambles Brian , Schuster Heike
Published: September 2003

In 2002 Birmingham libraries launched a marketing campaign to change their image and introduce a new branding. An integrated approach to strategic planning, performance measurement and marketing techniques enabled the campaign to achieve its objectives. The example of Birmingham libraries illustrates the various stages of a marketing campaign through planning, market research, defining objectives, target groups and messages, media planning, implementation and evaluation. It emphasises the link between the libraries’ strategy and concrete marketing targets. Birmingham libraries’ image campaign was awarded the CILIP and Emerald Public Relations and Publicity Award in 2002. The judges described the work as “a textbook example of a job done properly with serious professional support … this level of marketing for libraries should be encouraged”.
Looking back to see forward in services marketing: some ideas to consider
Authors: Cronin J. Joseph
Published: September 2003

The article considers the applicability of traditional attitude and other constructs in service quality research. It is suggested that the effects of perceived service quality may be masked by non‐linear relationships and under‐identified explanatory models. Constructs that might assist researchers and practitioners improve their service quality research and strategies are identified.
Customer expectations on service guarantees
Authors: Björlin Lidén Sara , Edvardsson Bo
Published: September 2003

Focuses on customer expectations on service guarantees. Theoretically, the basis consists of previous guidelines for service guarantee design. The empirical context is public transport, where customers that have invoked a service guarantee participate in focus groups. The results expand on prior research, which has argued that negative industry reputation is a hotbed for service guarantees and that the most preferred guarantee is unconditional; the paper’s results imply that customers prefer detailed regulations for when the guarantee is applicable, and that their general disbelief in a company with negative reputation makes the unconditional guarantee seem like a rip off. The results also indicate that the customers of a public service want the guarantee to be fair, that is, fairness in the possibility for all customers to invoke the guarantee, that all customers are familiar with the guarantee and that it cannot be misused by cheating customers. One of the contributions of the article is therefore to add “fairness” as a dimension to the previous guidelines suggested by Hart.
Mixed convection along a vertical cone for fluids of any Prandtl number: case of constant wall temperature
Authors: Pop I. , Groşan T. , Kumari M.
Published: September 2003

An analysis of steady laminar mixed convection boundary layer flow along a vertical cone of constant wall temperature is presented. A mixed convection parameter ξ, as proposed by Lin and Chen, is used to serve as a controlling parameter that determines the relative importance of the forced and the free convection flows. New coordinates and dependent variables are then defined in terms of ξ, so that the transformed non‐similar boundary layer equations give computationally efficient numerical solutions which are valid over the entire range of mixed convection flow from the forced convection limit to the free convection limit for fluids of any Prandtl number. The effects of the mixed convection parameter ξ and the Prandtl number Pr on the velocity and temperature profiles as well as on the skin friction and heat transfer coefficients are shown for both cases of buoyancy assisting and buoyancy opposing flow conditions.
Microscopic and macroscopic approach for natural convection in enclosures filled with fluid saturated porous medium
Authors: Massarotti N. , Nithiarasu P. , Carotenuto A.
Published: September 2003

In this paper, microscopic and macroscopic approaches to the solution of natural convection in enclosures filled with fluid saturated porous media are investigated. At the microscopic level, the porous medium is represented by different assemblies of cylinders and the Navier‐Stokes equations are assumed to govern the flow. To represent the flow in a macroscopic porous medium approach, the generalised flow model is employed. The characteristic based split scheme is used to solve the conservation equations of both approaches. In addition to the comparison between microscopic and macroscopic approaches of fluid saturated porous enclosures, cavities with interface between fluid saturated porous medium and single phase fluid are also investigated.
Using ethnography in strategic consumer research
Authors: Elliott Richard , Jankel‐Elliott Nick
Published: September 2003

This paper describes how ethnographic and quasi‐ethnographic research methods can be used in order to address the problems of the “limitations of asking” and that “people don’t always do what they say”, and to develop a “thick description” of the lived experience of consumers. A range of approaches are discussed and examples of their use in consumer research are given. Two case studies of ethnographic methods being used in strategic commercial research projects are described in detail. The implications for utilising ethnography in order to obtain managerially actionable insights are discussed.
Identifying and reaching an ethnic market: methodological issues
Authors: Pires Guilherme , Stanton John , Cheek Bruce
Published: September 2003

The potential for segmenting and targeting consumers, using ethnicity as a segmenting variable, is widely recognised in the marketing literature. However, attention to the problems of identifying and reaching a single, often relatively small, ethnic group, as opposed to some aggregate of groups, has been minimal. This paper proposes a framework for ethnic marketing research that is currently lacking. A method for conducting exploratory qualitative research of an ethnic group, for which little published information is available, is discussed with particular attention given to the sampling process. The proposed methodology, involving a symbiosis of symbolic interaction with phenomenological description, yields rich information about the group.