bluuebunny/crossref_metadata_2025 huggingface dataset:
Differential Effects of Oxidative Stress on Hepatic Endothelial and Kupffer Cell Eicosanoid Release in Response to Endothelin‐1
Authors: KARAA AMEL , KAMOUN WALID S. , XU HONG , ZHANG JAIN , CLEMENS MARK G.
Published: July 2007

Objective: The vasoconstrictor endothelin‐1 can induce vasomodulators release like nitric oxide in the liver. Here the authors explored whether endothelin‐1 can stimulate endothelial and Kupffer cells release of other vasomodulators under normal and stress conditions.

Methods: Cells were cultured for 24 h and treated with H2O2 (25 μM) for 6 h and subsequently with endothelin‐1 (10 nM) for 10 min. Eicosanoid release was assessed in the media by enzyme immunoassay.

Results: Endothelin‐1 mediated cPLA2 phosphorylation and increased prostaglandin (PG) I2, PGE2 and thromboxane A2 (TXA2) release in endothelial cells while it only increased TXA2 in Kupffer cells. H2O2 significantly increased PGI2, PGE2 and TXA2 in endothelial cells through an upregulation of cyclooxygenase‐2, thromboxane synthase A2, and phosphorylation of cPLA2. Endothelin‐1‐induced PGI2, PGE2, and TXA2 release in endothelial cells were inhibited by H2O2 correlating with the absence of further cPLA2 phosphorylation. In Kupffer cells, H2O2 only increased TXA2 synthesis and further endothelin‐1 stimulation of TXA2 was possible through a higher increase in cPLA2.

Conclusion: These results indicate that under normal conditions endothelial cells play a pivotal role in liver microcirculation regulation. Oxidative stress not only disrupts the basal balance of vasomodulators in the liver but also affects endothelin‐1‐induced effects in both Kupffer cells and endothelial cells.
Understanding emotions in context: the effects of language impairment on children's ability to infer emotional reactions
Authors: Spackman Matthew P. , Fujiki Martin , Brinton Bonnie
Published: July 2007

Background: Research indicates children with language impairment (LI) may experience social deficits extending beyond those expected due to their language deficits. In particular, it has been found that children with LI have difficulty with various aspects of emotional competence. One aspect of emotional competence is emotion understanding, which includes the ability to infer the emotions of oneself and others from social context.

Aims: To examine the ability of children with LI to infer the emotions elicited by specific social situations.

Methods & Procedures: Participants were presented with short scenarios in which the main character, Chris, was exposed to a situation that would be expected to elicit anger, fear, happiness or sadness. Children were then asked to indicate what emotion Chris experienced. Following selected scenarios, children were asked to talk about the emotions they associated with some of the scenarios. They were first asked why the character would feel a particular emotion (e.g. Why did Chris feel happy?) and then asked for a description of how the particular emotion would feel (e.g. How does it feel inside to be happy?).

Outcomes & Results: Both groups of children identified happiness most accurately, followed by sadness, fear and anger. Older children were significantly more accurate than younger children, and typically developing children were significantly more accurate than children with LI. Children with LI were less sophisticated in their descriptions of emotion than were typical children.

Conclusions: It is suggested that clinical interventions for children with LI should include activities designed to enrich children's emotion understanding, giving them opportunities to develop skills they may not acquire otherwise.
Butachlor impact on protein, free amino acid and glutamine contents, and on activity levels of aminotransferases, glutamate dehydrogenase and glutamine synthetase in the fresh water snail, Pila globosa (Swainson)
Authors: Rajyalakshmi T. , Srinivas T. , Swamy K. V. , Mohan P. Murali
Published: July 2007

Biochemical changes followed in the freshwater snail Pila globosa (Swainson) during exposure to sublethal concentrations of the herbicide butachlor (26.6 ppm) in the ambient medium, at 3,6,12,24 and 48 h intervals, were marked by a significant decrease in total and soluble proteins, and an increase in free amino acids in foot and hepatopancreas up to 12 h before gradually recovering. Aminotransferase activities and glutamine content decreased during the early periods of exposure, while glutamate dehydrogenase activity increased. After an intial elevation, glutamate synthetase activity decreased at later intervals. Maximum effect of butachlor on the enzymes was seen after 12 h exposure. The extent of increase or decrease in different parameters examined varied between the two tissues studied. These changes are discussed in relation to the toxic stress of butachlor.
Inhibition of microsomal lipid peroxidation by baicalein: A possible formation of an iron‐baicalein complex
Authors: Gao Dayuan , Sakurai Koichi , Katoh Mika , Chen Jimin , Ogiso Taketo
Published: July 2007

Baicalein decreased the production of thiobarbituric acid reactive substances, the rate of oxygen consumption and iron reduction in the reaction system of ascorbic acid with FeCl3. Superoxide dismutase, catalase and hydroxyl radical scavengers had no significant effect. Ironchelators had an inhibitory effect similar to that of baicalein. The production of thiobarbituric acid reactive substances of baicalein‐treated microsomes obtained by centrifugation after incubation with baicalein was not observed in the reaction system, but was stimulated by adding iron with increases in concentration. The amount of bound iron to microsomal membranes increased by increasing both the concentration of baicalein and iron. The amount of baicalein bound to microsomal membranes increased with increasing concentration of added baicalein. These results suggest that baicalein bound to microsomal membranes inhibits lipid peroxidation by formating an iron‐baicalein complex.
Formation of homo‐and heterooligomeric supramolecular structures by D‐glyceraldehyde‐3‐phosphate dehydrogenase and lactate dehydrogenase in reversed micelles of aerosol ot in octane
Authors: Levashov A. V. , Ugolnikova A. V. , Ivanov M. V. , Klyachko N. L.
Published: July 2007

The supramolecular structure of oligomeric enzymes can be specifically regulated by changing the size of an inner cavity of Aerosol OT reversed micelles in octane. Both D‐glyceraldehyde‐3‐phosphate dehydrogenase (GAPDH) and lactate dehydrogenase (LDH) reveal an ability to exist and function in monomeric, dimeric and tetrameric forms (homooligomers). Various heterooligomeric complexes, in particular, GAPDH monomer ‐ LDH monomer, GAPDH dimer ‐ LDH tetramer were detected in reversed micelles.
Cloning and expression of a Clostridium thermocellum xylanase gene in Escherichia coli
Authors: Jung Kyung Hwa , Lee Kang Moon , Kim Hoon , Yoon Ki‐Hong , Park Seung‐Hwan , Pack Moo Young
Published: July 2007

A Clostridium thermocellum xylanase gene, designated xynX, was cloned in Escherichia coli and was catagorized a novel gene as a result of the comparison of restriction patterns of the C. thermocellum xylanase genes so far reported. The xynX gene encodes a xylanase having the molecular weight of 105 kilodaltons. A number of smaller truncated proteins with activities towards 4‐methylumbelliferyl‐β‐d‐cellobioside and xylan were also produced. The enzyme hydrolyzed xylan to xylo‐oligosaccharide, indicating typical activity of endo‐β‐1,4‐xylanase. This endoxylanase hydrolyzed carboxymethylcellulose without notable reduction of the viscosity as an exo‐β‐1,4‐glucanase, even though the enzyme exhibited very low levels of activity against other soluble and insoluble cellulosic substrates.
Structural factors affect the interactions of anticardiotoxin antibodies and cobra venom cardiotoxins
Authors: Chang Long‐sen , Lo Yen‐ren , Lin Shinne‐ren
Published: July 2007

Two antibody preparations against cardiotoxins were raised by immunizing rabbits with cardiotoxin 1 and cardiotoxin 3, respectively. The two antibody preparations showed precipitin reactions with cardiotoxins 1, 2, 3 and 5, respectively. However, the results of competitive enzyme‐linked immunoassay revealed that the respective cardiotoxin molecules exhibited different reactivity toward anticardiotoxin antibodies. Moreover, the order of reactivity with antibodies was not in line with the degree of their sequence identity. This suggest that the anticardiotoxin antibodies may recognize conformational epitopes rather than sequential ones in the toxin molecules. Alternatively, the four cardiotoxins reacted well with the antibodies in the absence of competitor, suggesting that sequence variations with cardiotoxin molecules may not exclusively influence the potential use of the anticardiotoxin antibodies for the neutralization of the activity of cardiotoxin variants.
Nucleotide sequence and intergeminiviral homologies of the DNA‐A of papaya leaf curl geminivirus from India
Authors: Saxena Sangeeta , Hallan Vipin , Singh B. P. , Sane P. V.
Published: July 2007

Coat protein gene, rep protein gene and intergenic region of the genome of a whitefly transmitted geminivirus (WTG) causing severe leaf curl in papaya plants were PCR amplified, cloned and sequenced. Comparison of the amino acid sequence of the putative coat protein product of papaya leaf curl virus (PLCV) with some other mona and bipartite WTGs revealed a maximum of 89.8% homology with Indian cassava mosaic virus. The genomic organization of PLCV‐India is similar to other WTGs with bipartite genomes. Comparison of the coat protein N‐terminal 70 amino acid sequence (and other biological features) of PLCV with other geminiviruses shows that PLCV is a distinct geminivirus from India and is related to WTGs from the old world.
Purification and characterization of the tyrosinase isozymes of pine needles
Authors: Kong Kwang‐Hoon , Lee Jong‐Liong , Park Hee‐Joong , Cho Sung‐Hye
Published: July 2007

Three tyrosinase isozymes were purified to electrophoretic homogeneity from pine needles. The molecular weight of the three isozymes (P1, P2 and P3) were approximately 65000, 50000 and 45000, and the pI values were 6.2, 5.9 and 5.3, respectively. The three isozymes have a number of common properties. These include amino acid composition, substrate specificity, response to inhibition. The amino acid compositions of the three isozymes showed the characteristic high contents of glycine, serine and glutamic acid residues. The three isozymes exhibited high substrate specificity towards pyrogallol. The Km values of the three isozymes for L‐DOPA ranged from 8.7 to 10 raM. L‐ascorbic acid and β‐mercaptoethanol, glutathione and sodium diethyldithiocarbamate notably inhibited the enzymatic activities.
Inhibition studies on membrane adenosine deaminase from human placenta
Authors: Lupidi G. , Marmocchi F. , Cristalli G.
Published: July 2007

The ecto form of adenosine deaminase isolated from human placental membrane was tested towards its sensitivity against adenosine deaminase inhibitors, such as aza and deaza analogues of adenosine and erythro‐9‐(2‐hydroxy‐3‐nonyl)adenine (EHNA). Ki values of the inhibitors observed were similar to these obtained for the small form of adenosine deaminase purified from human erythrocytes, indicating that the presence of the binding protein on placental adenosine deaminase does not produce alteration in the binding of these inhibitors on the enzyme active site. The inhibition rate of 2′‐deoxycoformycin, one of the most potent ADA inhibitors is affected by the presence of the binding protein on human placental adenosine deaminase, that probably modulates the rearrangment of the active site produced by the binding with this tight‐binding inhibitor.
Cellular uptake and delivery monitoring of liposome/DNA complexes during in vitro transfection of CFTR gene
Authors: Serafino Anna Lucia , Novelli Giuseppe , Sario Sabrina Di , Colosimo Alessia , Amicucci Paola , Sangiuolo Federica , Mossa Giuseppe , Dallapiccola Bruno
Published: July 2007

The cellular uptake and distribution of cationic liposomes Dc‐Chol/DOPE‐CFTR gene complexes were assessed by electronic and confocal laser scanner microscopy (CLSM) for the CFTR gene transfer to human adenocarcinoma and tracheal epithelial cell lines. Cationic lipid forms unilamellar and multilamellar vesicles capable of rapid and efficient transport of gene into target cells. The number of fluorescent complexes was increasing with time in cells up to 6 hours showing a punctate and homogeneous DNA distribution in the cytoplasmatic and nuclear compartments, including the nucleolus. No significant difference in the biochemical and cellular behavior was observed between the investigated system and other systems previously tested. This study adds new insights into the CFTR cationic liposome‐mediated gene delivery.
Cloning, expression, and characterization of a cDNA encoding snake venom metalloprotease
Authors: Jeon Ok‐Hee , Kim Doo‐Sik
Published: July 2007

A cDNA clone, MT‐c, encoding metalloprotease was isolated from snake (Agkistrodon halys brevicadus) venom gland cDNA library. Deduced amino acid sequence indicated that MT‐c is composed of a signal sequence, amino‐terminal propeptide, a central metalloprotease domain, and a Lys‐Gly‐Asp (KGD) disintegrin domain. The partial cDNA encoding metalloprotease and disintegrin domain was subcloned and expressed in E. coll. The expressed MT‐c protein was purified and successfully refolded into functional form retaining the enzyme activity. Analyses of the purified recombinant protease activity revealed that the enzyme hydrolyzes extraceUular matrix proteins including type I gelatin, type 1V and type V collagen, while type I, II, III collagens and fibronectin were insensitive to the proteolytic digestion. The recombinant enzyme was also able to degrade fibrinogen by specifically cleaving Aα chain of the protein.
Uptake of vitamin E succinate by the skin, conversion to free vitamin E, and transport to internal organs
Authors: Trevithick John R. , Mitton Kenneth E.
Published: July 2007

The percent solubility at 34°C (skin temperature) of radioactive tocopherol succinate was determined for a number of edible oils, and a semisynthetic oil, Myritol 318 (Henkel, Kankakee, IL, a medium chain triglyceride prepared from fractionated coconut oil). Its solubility in Myritol 318 was approximately 50% better than any of the other oils. 14C‐tocopherol succinate was diluted (1) into pure Myritol 318, a cosmetic base or (2) 50% tocopherol succinate in Myritol 318. These preparations were applied topically to a 2 cm diameter circle of the back saddle skin of a hairless mouse (strain skh‐1). After 24 hr, up to 65% of the label was absorbed by the skin and was also found in skin removed from areas of the back other than the application area, and internal organs such as liver and heart. Up to 6% was hydrolysed to free tocopherol. Topical treatment may be an alternative to oral administration in gastrointestinal malabsorption diseases.
Ethnopluralism: Panacea for East Central Europe?
Authors: Karklins Rasma
Published: July 2007

Worldwide, ethnopolitics takes on various shapes. Yet, while politics involving ethnicity can be either conflictual, competitive, or cooperative, analysts typically focus either on instances of conflict or ignore the multiethnicity of states by sticking to “the comfortable integrationist presumptions of the 1950s.” All too rarely does one find analyses of policies that work in difficult situations. This global trend is intensified in the case of Eastern Europe. As this region has suffered instances of ethnic politics gone wrong—most recently in the former Yugoslavia—many analysts assume that constructive approaches to ethnic relations are impossible, even though they are needed more than ever. Here, I outline a model of ethnopolitics which is both democratic and constructive, has been used in East Central Europe in the past, and has potential for the future. In presenting the case for ethnopluralism, I outline a promising alternative to ethnic conflict or neglect.
Detection of Specific Protein Bands with Melatonin‐Like Immunoreactivity in Different Cell Lines and Human Brain Regions
Authors: Lahiri Debomoy K. , Davis Dawn , Nurnberger John I.
Published: July 2007

The pineal hormone melatonin regulates various neural and endocrine processes involved in mammalian circadian rhythms. To understand how melatonin mediates these functions, we investigated melatonin‐like immunoreactivity (MLI) in cell extracts and human brain. In Western immunoblots, we detected highmolecular‐mass protein bands (85‐135 kDa) that specifically reacted with the anti‐melatonin antibody. The specific protein bands were present in cell extracts from the human brain and cell lines of different origins. The immunoreactive signal of the 135‐kDa protein band was highest in a neuroendocrine PC12 cell line, which was 10‐fold higher than the signal observed in any cell extracts used. The commercial antibody employed in the Western blots was further purified against serum proteins and thyroglobulins. We have previously reported that the antibody against melatonin recognizes MLI as detected by a sensitive RIA. In the present report we have detected the putative melatonin‐specific binding proteins, which could contribute to the MLI. Our results suggest that melatonin binds with specific proteins in different cellular and brain extracts, the protein(s) being maximally synthesized in PC12 cells. These results may indicate a group of yet unknown proteins sharing a melatonin‐like epitope or the presence of melatonin‐binding protein(s) that regulate availability of free melatonin, or both.
Correlation between EBV DNA and Rearrangement and Expression of Bcl‐2 Gene in Aggressive Non‐Hodgkin's Lymphoma
Authors: Eissa Sanaa , Kassim Samar K. , Imam Maha , Khalifa Ali
Published: July 2007

Previous in vitro studies have shown that bcl‐2 expression can be induced by transfection of Epstein‐Barr virus (EBV)‐negative non‐Hodgkin's lymphoma (NHL) cell lines with EBV. This induced expression of bcl‐2 isimportantforthelong survivalofEBV‐positive cells and might be a first step in tumorigenesis. The purpose of the presentstudy was to investigate the possibility ofsimilar correlation between bcl‐2 expression and EBV infection in vivo in a cohort of patients with aggressive NHL, who were uniformly evaluated and treated with effective chemotherapy. The 42 patients included were 25‐65 years old. None had prior treatment, discordant lymphoma, or human immunodeficiency virus seropositivity. Fresh biopsied samples were obtained and stored frozen for analysis of bcl‐2 gene rearrangement major break point and of EBV DNA by PCR. Bcl‐2 protein expression was estimated by Western blot, and enzyme immunoassay. With a median follow‐up of 30 months, overall survival (OS) and disease‐free survival (DFS) were measured to determine the prognostic significance of these variables. Analyzable DNA was present in all samples, 24% demonstrating bcl‐2 rearrangement and 33% showing EBV DNA. Patients with bcl‐2 gene rearrangement tended to have shorter DFS, and OS than patients without translocation. Bcl‐2 protein expression was not correlated to gene rearrangement and had no significant influence on survival. The presence of EBV DNA in NHL had no prognostic significance but was correlated to bcl‐2 expression. EBV‐positive tumors showed higher bcl‐2 expression than EBV‐negative tumors did. Our results suggest a role of EBV infection in inducing bcl‐2 expression as a survival factor for EBV‐positive cells.
Gbetagamma‐Mediated Signaling: New Therapeutic Target for Proliferative Vascular Disease
Authors: Iaccarino Guido , Koch Walter J.
Published: July 2007

Proliferation of vascular smooth muscle (VSM) severely affects the outcome of coronary artery bypass and angioplasty procedures, causing the failure of venous grafts or restenosis of the reopened vessel. Investigation into the mechanisms underlying the process of VSM cellular proliferation has provided evidence that intracellular signaling mechanisms triggered by extracellular hormonal factors acting through G protein‐coupled receptors, can mediate and sustain this pathological process. Inhibition of common pathways of G protein‐coupled receptor signaling has recently proven effective in preventing VSM cellular activation and proliferation. In particular, inhibition of the Gbetagamma‐mediated mitogen‐activated protein (MAP) kinase signaling pathway results in the inhibition of VSM proliferation in vitro. Moreover, use of adenoviral vectors to deliver a peptide inhibitor of Gbetagamma signaling in vivo has resulted in inhibition of intimal hyperplasia in experimental models of vein‐graft failure and restenosis.
Single‐Stranded Oligodeoxyribonucleotides Are Substrates of Fpg Protein from Escherichia Coli
Authors: Ishchenko Alexander A. , Bulychev Nikolai V. , Maksakova Galia A. , Johnson Francis , Nevinsky Georgy A.
Published: July 2007

The interaction of Escherichia coli Fpg protein, which catalyzes excision of several damaged purine bases including 8‐oxoguanine (oxoG) from DNA with a set of single‐ (ss) and double‐stranded (ds) 23‐mer oligodeoxyribonucleotides (ODNs) containing 8‐oxoguanine(s) at various positions, has been investigated. The affinities of different ss ODNs (KM = 0.55‐1.3 muM) were shown to be 12‐170 times less than those for corresponding ds ODNs (KM = 6‐60 nM). Depending on the position of the oxoG within the ODNs, relative initial rates of conversion of ss substrates may be less than, comparable, or greater than those for ds ODNs. The enzyme can remove 5′‐terminal oxoG from ODNs only if the 5′‐end is phosphorylated. Fpg does not release oxoG residues from the ultimate and penultimate 3′‐terminal positions. Duplexes containing two adjacent oxoG are poor substrates for the glycosylase.
Mechanism of Dihydrolipoate Stimulation of the Mitochondrial Permeability Transition: Effect of Different Respiratory Substrates
Authors: Morkunaite Sarune , Teplova Vera V. , Saris Nils‐Erik L.
Published: July 2007

The stimulation of the mitochondrial permeability transition (MPT) by dihydrolipoate (DHLA) was studied in rat liver mitochondria in the presence of different respiratory substrates. The Ca2+ threshold for the induction of MPT was lowest for pyruvate, followed by 2‐hydroxybutyrate, 2‐oxoglutarate, glutamate plus malate, and succinate plus rotenone, both in the presence and absence of DHLA. DHLA was not able to induce MPT in the absence of Ca2+, in the presence of cyclosporin A, or rotenone with pyridine nucleotide‐dependent substrates. The difference in sensitivity of MPT to DHLA with various substrates was correlated with the redox state of pyridine nucleotides but not the redox state of glutathione. These findings demonstrate that DHLA induced MPT pore opening through the P‐site thiol. The similarities between the effect of DHLA and that of production of reactive oxygen species found in model experiments suggest that DHLA stimulates MPT by production of reactive oxygen species that exhaust the antioxidant defence.
A CD2‐Based Model of Yeast a‐Agglutinin Elucidates Solution Properties and Binding Characteristics
Authors: Grigorescu Arabela , Chen Min‐hao , Zhao Hui , Kahn Peter C. , Lipke Peter N.
Published: July 2007

We have previously shown that the Saccharomyces cerevisiae
Functional Protection of Human Haemoglobin Against Protein Dissociation
Authors: Brittain Thomas
Published: July 2007

The spectroscopic and functional properties of human adult haemoglobin are clearly disrupted by concentrations of urea > 0.4 M. This disruption of structure and function is completely obviated by the presence of 0.2 M trimethylamine N‐oxide (TMAO). Spectroscopic data suggest that TMAO prevents urea‐induced production of high‐spin haem. Functional analysis shows that TMAO exerts its influence by counteracting urea‐induced destabilisation of the T state of the haemoglobin protein. Further studies show, however, that TMAO is not able to exert any such stabilising influences in the presence of high concentrations of typical organic solvent denaturants.
Vesicular Stomatitis Virus (VSV) Therapy of Tumors
Authors: Balachandran Siddharth , Barber Glen N.
Published: July 2007

Vesicular stomatitis virus (VSV) is an essentially nonpathogenic negative‐stranded RNA virus, the replication of which is extremely sensitive to the antiviral effects of interferon (IFN). We demonstrate here that VSV selectively induces the cytolysis of numerous transformed human cell lines in vitro, with all the morphological characteristics of apoptotic cell death. Importantly, VSV can also potently inhibit the growth of p53‐null C6 glioblastoma tumors in vivo without infecting and replicating in normal tissue. With our previous findings demonstrating that primary cells containing the double‐stranded RNA‐activated protein kinase PKR and a functional IFN system are not permissive to VSV replication, these results suggest that signaling by IFN may be defective in many malignancies. Thus VSV might be useful in novel therapeutic strategies for targeting neoplastic disease.
Hydrogen Peroxide. Ubiquitous in Cell Culture and In vivo?
Authors: Halliwell Barry , Clement Marie Veronique , Ramalingam Jejakumar , Long Lee Hua
Published: July 2007

Hydrogen peroxide (H2O2) is widely regarded as a cytotoxic agent whose levels must be minimized by the action of antioxidant defence enzymes. In fact, H2O2 is poorly reactive in the absence of transition metal ions. Exposure of certain human tissues to H2O2 may be greater than is commonly supposed; levels of H2O2 in the human body may be controlled not only by catabolism but also by excretion, and H2O2 could play a role in the regulation of renal function and as an antibacterial agent in the urine. Cell culture is a widely used method for the investigation of “physiological” processes such as signal transduction and regulation of gene expression, but chemical reactions involving cell culture media are rarely considered. Addition of reducing agents to commonly used cell‐culture media can lead to generation of substantial amounts of H2O2. Some or all of the reported effects of ascorbic acid and polyphenolic compounds (e.g., quercetin, catechin, epigallocatechin, epigallocatechin gallate) on cells in culture may be due to H2O2 generation by interaction of these compounds with cell culture media.
Oxidation of Methionine in Proteins: Roles in Antioxidant Defense and Cellular Regulation
Authors: Levine Rodney L. , Moskovitz Jackob , Stadtman Earl R.
Published: July 2007

The roles of methionine residues in proteins have not been well defined, but a review of available studies leads to the conclusion that methionine, like cysteine, functions as an antioxidant and as a key component of a system for regulation of cellular metabolism. Methionine is readily oxidized to methionine sulfoxide by many reactive species. The oxidation of surface exposed methionines thus serves to protect other functionally essential residues from oxidative damage. Methionine sulfoxide reductases have the potential to reduce the residue back to methionine, increasing the scavenging efficiency of the system. Reversible covalent modification of amino acids in proteins provides the mechanistic basis for most systems of cellular regulation. Interconversion of methionine and methionine sulfoxide can function to regulate the biological activity of proteins, through alteration in catalytic efficiency and through modulation of the surface hydrophobicity of the protein.
Knowledge management in Iran aerospace industries: a study on critical factors
Authors: Jafari Mostafa , Akhavan Peyman , Rezaee Nour Jalal , Fesharaki Mehdi N.
Published: July 2007

Purpose

This paper aims to discuss the essential issues of knowledge management adoption, in order to establish a knowledge management program in Iran Aerospace Industries Organization (AIO).

Design/methodology/approach

This paper has identified critical factors of knowledge management through Iran AIOs based on a comprehensive review of recent literature. For this purpose, a questionnaire was designed, applied and then analyzed by some statistical methods. The results discussed various perspectives from the knowledge management point of view, and provided some critical factors and a regression model for showing essential issues of subject.

Findings

The statistical analysis determined eight factors as critical issues in this large‐scale case study. These factors are “team working and KM features,” “leadership and commitment of CEO,” “appropriate organizational infrastructure,” “pilot, benchmarking and KM systems,” “job enrichment and security,” “culture, change management and strategy,” “collaborative and flexible organization” and “training and learning.” The overall results from the case study were positive as well, thus reflecting the appropriateness of the suggested regression model.

Research limitations/implications

The extracted factors can act as a guideline for KM adoption in the organizations. This helps to ensure that the essential issues are covered during design and implementation phase of KM program. For academics, it provides a common language to discuss and study the factors crucial for knowledge management.

Originality/value

The paper may present high value to researchers in the knowledge management field and to practitioners involved with KM program in the organizations. This study further provides an integrated perspective of critical issues for KM adoption in the high‐tech industries including the aerospace industry. It gives valuable information and guidelines that hopefully will help the leaders to consider the important issues during knowledge management establishment in the organization.
Stereo vision‐based autonomous navigation for lunar rovers
Authors: Cui Pingyuan , Yue Fuzhan
Published: July 2007

Purpose

To provide an autonomous navigation system to endow lunar rovers with increased autonomy both for exploration achievement of scientific goals and for safe navigation.

Design/methodology/approach

First, algorithm and technique of initial position determination of lunar rovers are introduced. Then, matched‐features set is build by multi steps of image processing such as feature detection, feature tracking and feature matching. Based on the analysis of the image processing error, a two‐stage estimation algorithm is used to estimate the motion, robust linear motion estimation is executed to estimate the motion initially and to reject the outliers, and Levenberg‐Marquardt non‐linear estimation is used to estimate the motion precisely. Next, a weighted ZSSD algorithm is presented to estimate the image disparities by analyzing the traditional ZSSD. Finally, a virtual simulation system is constructed using the development tool of open inventor, this simulation system can provide stereo images for simulations of stereo vision and motion estimation techniques, simulation results are provided and future research work is addressed in the end.

Findings

An autonomous navigation system is build based on stereo vision, the motion estimation algorithm and disparity estimation algorithm are developed.

Research limitations/implications

The field test will be done in the near future to valid the autonomous navigation algorithm presented in this paper.

Practical implications

A very useful source of information for graduate students and technical reference for researchers who work on lunar rovers.

Originality/value

In this paper, stereo vision‐based autonomous navigation techniques for lunar rovers are discussed, and an autonomous navigation scheme which based on stereo vision is presented, and the validity of all the algorithms involved is confirmed by simulations.
A surrogate model for interference prevention in the limaçon‐to‐limaçon machines
Authors: Sultan Ibrahim A.
Published: July 2007

Purpose

This paper aims to replace the complicated iterative procedure used to prevent interference in limaçon‐to‐limaçon machines by a simplified mathematical equation which can be solved by a straightforward substitution of the required clearance value.

Design/methodology/approach

The input data to the iterative procedure and the obtained results have been employed in regression models to construct the sought after equation. Searching for a proper form of this equation involved numerical experiments to study the effects of the various model parameters on the system response.

Findings

The numerical experiments conducted proved to be an effective model construction technique, and the regression model proposed has been found extremely accurate in the specified parameter space.

Research limitations/implications

The proposed equation is applicable within the parameter range chosen for the study. This range is the one often used for industrial applications. Should the parameters selected for a specific design fall outside the specified range, the proposed model structure may have to be varied to maintain a desirable level of accuracy.

Practical implications

The interference study is a part of the iterative procedure employed to design the dimensions of the limaçon‐to‐limaçon machine. This iterative procedure searches for the proper design amongst hundreds of various possible solutions. The results of this paper will ensure a much faster convergence for the design procedure, since the interference study will be eliminated from the iterative section of the analysis.

Originality/value

The paper offers a valid and accurate model that can be efficiently used for the intended purpose.
Asian brands without borders: regional opportunities and challenges
Authors: Cayla Julien , Eckhardt Giana M.
Published: July 2007

Purpose

This study aims to analyze Asian branding strategies at the regional level, and provide a map of opportunities and challenges for Asian regional branding.

Design/methodology/approach

The study takes, a multi‐sited interpretive approach and interview 22 brand managers throughout the Asian region. The length of interviews was approximately 1.5 hours/respondent. In‐depth case studies of two prominent pan‐Asian brands, Tiger Beer and Zuji, were also conducted. An interpretive analysis to this data set was applied and five themes were developed.

Findings

The two major challenges for regional Asian branding are negative country of origin perceptions and regional positioning being inherently fragile. Despite these key challenges, our respondents saw clear opportunities for regional branding initiatives. Brands can achieve a regional positioning by focusing on Asian modernity rather than on common cultural heritage. They can also capitalize on newfound Asian pride and confidence, and finally they can use a Western stamp of approval to signal to Asians the viability of the brand.

Originality/value

The paper extends previous work on the globalization of marketing activities by advancing the region as an important unit of analysis. It helps understand the development of brands in a part of the world that is becoming more important at the economic and political level. The study shows how marketers are shaping culture in the Asian context. Finally, the paper contributes a better understanding of the opportunities and challenges associated with a regional positioning and the development of regional branding strategies.
Who are the new amphetamine users? A 10‐year prospective study of young Australians
Authors: Degenhardt Louisa , Coffey Carolyn , Carlin John B. , Moran Paul , Patton George C.
Published: July 2007

Aims  Despite good evidence of increased availability and use of amphetamines world‐wide, relatively little is known about the epidemiology of young adult amphetamine use; relationships with social functioning, other drug use and mental health at this age; nor of the adolescent predictors of such use. We examined these issues using a representative cohort of young people followed‐up in Victoria, Australia.

Methods  A stratified, random sample of 1943 adolescents was recruited from secondary schools across Victoria at age 14–15 years. This cohort was interviewed on eight occasions until the age of 24–25 years (78% follow‐up at that age). Cross‐sectional and predictive associations were assessed using logistic regression.

Results  At age 24 years, 12% of the sample had used amphetamines in the past year, with 1–2% using at least weekly. Young adult amphetamine use was predicted strongly by adolescent drug use and was associated robustly with other drug use and dependence in young adulthood. Associations were stronger for more frequent users. Among young adults who had not been using amphetamines at age 20 years, the strongest predictor of use at age 24 years was the use of other drugs, particularly cannabis, at 20 years. Psychological distress did not predict independently an increased likelihood of amphetamine use in this cohort.

Conclusion  Young people in Australia using amphetamine at age 24 years are highly likely to be significant polydrug users. The risks for both initiation of young adult amphetamine use, and maintenance of such use, pertain to the heavy use of other drugs. Interventions for heavy amphetamine users at this age are likely to require attention to multiple drug problems.
Serotonin and neuroprotection in functional bowel disorders
Authors: Gershon M. D. , Liu M.‐t.
Published: July 2007

Abstract  The 5‐HT4 partial agonist tegaserod is effective in the treatment of chronic constipation and constipation predominant irritable bowel syndrome. 5‐HT4 receptors are located on presynaptic terminals in the enteric nervous system. Stimulation of 5‐HT4 receptors enhances the release of acetylcholine and calcitonin gene related peptide from stimulated nerve terminals. This action strengthens neurotransmission in prokinetic pathways, enhancing gastrointestinal motility. The knockout of 5‐HT4 receptors in mice not only slows gastrointestinal activity but also, after 1 month of age, increases the age‐related loss of enteric neurons and decreases the size of neurons that survive. 5‐HT4 receptor agonists, tegaserod and RS67506, increase numbers of enteric neurons developing from precursor cells and/or surviving in culture; they also increase neurite outgrowth and decrease apoptosis. The 5‐HT4 receptor antagonist, GR113808, blocks all of these effects, which are thus specific and 5‐HT4‐mediated. 5‐HT4 receptor agonists, therefore, are neuroprotective and neurotrophic for enteric neurons. Because the age‐related decline in numbers of enteric neurons may contribute to the dysmotilities of the elderly, the possibility that the neuroprotective actions of 5‐HT agonists can be utilized to prevent the occurrence or worsening of these conditions should be investigated.
Recent advances in understanding the role of serotonin in gastrointestinal motility in functional bowel disorders: alterations in 5‐HT signalling and metabolism in human disease
Authors: Spiller R.
Published: July 2007

Abstract Serotonin (5‐hydroxytryptamine, 5‐HT) is present in abundance within the gut, most stored in enterochromaffin cell granules. It is released by a range of stimuli, most potently by mucosal stroking. Released 5‐HT stimulates local enteric nervous reflexes to initiate secretion and propulsive motility. It also acts on vagal afferents altering motility and in large amounts induces nausea. Rapid reuptake by a specific transporter (serotonin transporter, SERT) limits its diffusion and actions. Abnormally increased 5‐HT is found in a range of gastrointestinal disorders including chemotherapy‐induced nausea and vomiting, carcinoid syndrome, coeliac disease, inflammatory bowel disease and irritable bowel syndrome (IBS) with diarrhoea (IBS‐D), especially that developing following enteric infection. Impaired SERT has been described in IBS‐D and might account for some of the increase in mucosal 5‐HT availability. 5‐HT3receptor antagonists inhibit chemotherapy‐induced nausea and diarrhoea associated with both carcinoid syndrome and IBS. While IBS‐D is associated with increased 5‐HT postprandially, IBS with constipation (IBS‐C) is associated with impaired 5‐HT response and responds to 5‐HT4agonists such as Prucalopride and 5‐HT4partial agonists such as Tegaserod.
Some physicochemical, microbiological, and sensory properties of tulum cheese produced from ewe's milk via a modified method
Authors: CEYLAN ZİYA GÖKALP , ÇAǦLAR ABDULLAH , ÇAKMAKÇI SONGÜL
Published: July 2007

The purpose of this research was to investigate an alternative way to manufacture Erzincan tulum cheese in order to shorten production time and improve food safety. By adding 0.5% starter culture (Streptococcus salivarius ssp. thermophilus and Lactobacillus delbrueckii ssp. bulgaricus cultures at a 1 : 1 ratio) to pasteurized ewe's milk (65°C for 30 min), the required time for manufacturing Erzincan tulum cheese was shortened from the traditional 10–12 days to 2 days. The cheeses manufactured with the modified method were ripened in three different packaging materials: goatskin, plastic, and ceramic. Physicochemical, microbiological, and sensory properties of the Erzincan tulum cheese were obtained during the ripening period at intervals of 2, 30, 60, and 90 days, and compared with those properties of samples manufactured by the traditional method. Significant microbiological and physicochemical differences were found between the modified samples and the traditional samples (P < 0.01). However, the modified samples and the traditional samples were statistically similar in sensory properties to the exception of the modified sample packaged in plastic.
Fabrication of Ceramic Microscale Structures
Authors: Christian  , Kenis Paul J. A.
Published: July 2007

Ceramics are attractive materials for engineering applications involving high temperatures and corrosive chemicals. Here, an inexpensive and reproducible ceramic microfabrication technology was used to fabricate high‐density alumina structures for applications in microchemical systems. The new method is based on the gelcasting procedure, but key drying and sintering steps have been adjusted to avoid warpage and cracking of the final structures. Centimeter‐scale ceramic structures with submillimeter features can be accurately replicated from an elastomeric mold. Further study of the effect of alumina particle size, Dp, on the smallest achievable and reproducible feature size showed that excellent replication of patterns can be achieved as long as the dimensions of features in the mold are greater than 30Dp for the range of Dp from 0.3 to 3.0 μm.
Polymorphisms in NACHT‐LRR (NLR) genes in atopic dermatitis
Authors: Macaluso Filippina , Nothnagel Michael , Parwez Qumar , Petrasch‐Parwez Elisabeth , Bechara Falk Georges , Epplen Joerg Thomas , Hoffjan Sabine
Published: July 2007

Abstract:  Atopic dermatitis (AD) is a chronic skin disease affecting up to 15% of children in industrialized countries. AD belongs to the group of atopic disorders characterized by excessive immune reactions to ubiquitous antigens. Complex interactions between genetic and environmental factors have been suggested for atopic disorders. Dysregulation of the innate immune system appears crucial for the pathogenesis of AD. The NACHT‐LRRs (NLRs) represent a group of innate immune receptors with special relevance for inflammatory processes. In order to investigate the role of variation in NLR genes for AD, we genotyped 23 single nucleotide polymorphisms (SNPs) in seven selected NLR genes (CARD4, CARD15, CARD12, NALP1, NALP3, NALP12, MHC2TA) in 392 AD patients and 297 controls by restriction enzyme digestion or TaqMan assays. Single‐SNP analysis demonstrated significant associations of the CARD15_R702W variation and the NALP12_In9 T‐allele with AD (P = 0.008 and P = 0.03, resp.; insignificant after Bonferroni correction). In the CARD4 gene, a rare haplotype was more frequent in AD patients than in controls. Interactions between all pairs of SNPs in the seven genes were analysed by logistic regression. Significant interactions comprised SNPs in the CARD4 gene (CARD4_In1 and CARD4_Ex6, P = 6.56 × 10−7; CARD4_Prom und CARD4_Ex6, P = 2.45 × 10−4) and promoter polymorphisms in the CARD12 and NALP1 genes (P = 4.31 × 10−4). In conclusion, variation in individual genes from the NLR family as well as interactions within this group of innate immune receptor genes could play a role in AD pathogenesis. Investigations in other populations and functional studies are warranted to clarify contributions of NLR variation for this frequent skin disease.
Flip-Flop of Fluorescently Labeled Phospholipids in Proteoliposomes Reconstituted with
Saccharomyces cerevisiae
Microsomal Proteins
Authors: Vehring Stefanie , Pakkiri Leroy , Schröer Adrien , Alder-Baerens Nele , Herrmann Andreas , Menon Anant K. , Pomorski Thomas
Published: July 2007

A phospholipid flippase activity from the endoplasmic reticulum (ER) of the model organism
Saccharomyces cerevisiae
has been characterized and functionally reconstituted into proteoliposomes. Analysis of the transbilayer movement of acyl-7-nitrobenz-2-oxa-1,3-diazol-4-yl (acyl-NBD)-labeled phosphatidylcholine in yeast microsomes using a fluorescence stopped-flow back exchange assay revealed a rapid, ATP-independent flip-flop (half-time, <2 min). Proteoliposomes prepared from a Triton X-100 extract of yeast microsomal membranes were also capable of flipping NBD-labeled phospholipid analogues rapidly in an ATP-independent fashion. Flippase activity was sensitive to the protein modification reagents
N
-ethylmaleimide and diethylpyrocarbonate. Resolution of the Triton X-100 extract by velocity gradient centrifugation resulted in the identification of a ∼4S protein fraction enriched in flippase activity as well as of other fractions where flippase activity was depleted or undetectable. We estimate that flippase activity is due to a protein(s) representing ∼2% (wt/wt) of proteins in the Triton X-100 extract. These results indicate that specific proteins are required to facilitate ATP-independent phospholipid flip-flop in the ER and that their identification is feasible. The architecture of the ER protein translocon suggests that it could account for the flippase activity in the ER. We tested this hypothesis using microsomes prepared from a temperature-sensitive yeast mutant in which the major translocon component, Sec61p, was quantitatively depleted. We found that the protein translocon is not required for transbilayer movement of phospholipids across the ER. Our work defines yeast as a promising model system for future attempts to identify the ER phospholipid flippase and to test and purify candidate flippases.