bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of Processing Conditions On the Peel Behavior of Polyethylene/ Polybutene-1 Peel Systems
Authors: Nase Michael , Langer Beate , Grellmann Wolfgang
Published: August 2009

The specific peel system low-density polyethylene/isotactic polybutene-1 (PE-LD/iPB-1), which is often used for protective packages, was investigated in this study. The required peel force to open the package depends on the content of iPB-1 and on the processing conditions of the blowing process. Commercial products have a constant amount of iPB-1. Thus, a defined peel force can be adjusted by varying the processing conditions. The standard peel system PE-LD with 6 wt% iPB-1 was investigated in dependence on the processing conditions. The most important processing parameters of the processing line (extruder, die head, tube forming area) were varied and their influence on the peel properties was examined. For example the temperatures of the melt within the extruder, the size of the die gap within the die head, and the cooling behavior of the film bubble were investigated. Higher melt temperatures within the extruder decreased the peel force. The investigations also revealed a strong dependence of the peel force on the size of the die gap and on the degree of cooling. The new developed parameter time of solidification was used to characterize the cooling behavior.
Actors' Interests and Local Contexts in Intrafirm Conflict: The 2004 GM and Opel Crisis
Authors: Blazejewski Susanne
Published: August 2009

Research on industrial relations in MNCs remains limited to aggregate concepts and dominant actor groups. Focusing on a case study of the 2004 wildcat strike at GM Bochum, Germany, this paper argues for the inclusion of genuinely local, micro-level perspectives and marginalised actors. It makes use of an extended framework of actor embeddedness, which introduces interests and situations as core variables. The case analysis shows how diverging interests of Opel shop stewards, workers and works council members led to a multiplication of conflict lines and the development of competing rationalities within the workforce.
The Emergence of China and India as New Competitors in MNCs' Innovation Networks
Authors: Bruche Gert
Published: August 2009

The globalisation of business research and development (R&D) was initially confined to developed countries, primarily to the triad of North America, Western Europe and Japan. Around the turn of the millennium, multinational companies (MNCs) increasingly started to include developing countries in their R&D value chain, with a particular preference for China and India. Based on the scattered yet growing evidence, this paper argues that the shift of MNC R&D to China and India is still limited in sectoral and regional scope. The investment is initially more market-seeking in China and more resource-seeking in India, with a tendency to evolutionary learning-based upgrading in both countries. Despite the dynamism in these developments, it seems that knowledge integration and appropriation remains hierarchical and firmly rooted in the triad-based R&D centres. Although alarmist and techno-nationalist arguments, predominantly from the US, of an imminent loss of position in the global innovation contest are exaggerated, these developments may nevertheless herald a historic shift in the global loci of innovation and power.
Cost Reduction through Relocation, or the Construction of Myths in Discourse
Authors: Piotti Geny
Published: August 2009

The findings of recent studies into relocation by German companies are puzzling: companies relocate because they are willing to cut costs, but entrepreneurs and managers seem to have failed to predict further and sometimes fatal costs associated with relocation. This paper sheds light on why relocation has become a general trend among German companies, despite those inefficiencies and costs. It points to the role of the discourse in creating the myth of relocation as a strategy to reduce costs. Discourse can in fact help to diffuse ideas independently of their empirical truth and give voice to influential actors who are able to induce isomorphic processes. In order to give an account of why companies' decisions to relocate have become so popular in Germany, regardless of their economic soundness, the paper draws on an analysis of German newspapers and business press that were published between January 1990 and July 2005.
Dynamic accumulation of plasmacytoid dendritic cells in lymph nodes is regulated by interferon-β
Authors: Gao Yunfei , Majchrzak-Kita Beata , Fish Eleanor N. , Gommerman Jennifer L.
Published: August 2009

Plasmacytoid dendritic cells (pDCs) represent a major cellular component of our front-line defense against viruses because of their capacity to rapidly secrete type I interferon (IFN)–α and -β after infection. Constant immunosurveillance of the host requires that lymphocytes traffic through lymph nodes (LNs) to sample antigen, yet little is known about the dynamics of pDC accumulation within the secondary lymphoid organs. Here we show that pDCs readily accumulate within the secondary lymphoid organs of mice after virus infection. Interestingly, retention of pDC within LNs is enhanced in the presence of the sphingoshine-1-phosphate receptor agonist FTY720 in a manner similar to that observed for B and T lymphocytes. Ex vivo comparison of mouse pDCs with lymphocytes revealed that pDCs express sphingoshine-1-phosphate 4 and also constitutively express CD69, which is further up-regulated upon virus infection. In IFN-β−/− mice, accumulation of pDC and lymphocytes within LNs is reduced both during viral infection and under steady state conditions, and these defects can be reversed by adding recombinant IFN-β in vivo. These data suggest that pDC and lymphocytes use similar mechanisms for retention within LNs and that these processes are influenced by IFN-β even in the absence of viral infection.
MDS and secondary AML display unique patterns and abundance of aberrant DNA methylation
Authors: Figueroa Maria E. , Skrabanek Lucy , Li Yushan , Jiemjit Anchalee , Fandy Tamer E. , Paietta Elisabeth , Fernandez Hugo , Tallman Martin S. , Greally John M. , Carraway Hetty , Licht Jonathan D. , Gore Steven D. , Melnick Ari
Published: August 2009

Increasing evidence shows aberrant hypermethylation of genes occurring in and potentially contributing to pathogenesis of myeloid malignancies. Several of these diseases, such as myelodysplastic syndromes (MDSs), are responsive to DNA methyltransferase inhibitors. To determine the extent of promoter hypermethylation in such tumors, we compared the distribution of DNA methylation of 14 000 promoters in MDS and secondary acute myeloid leukemia (AML) patients enrolled in a phase 1 trial of 5-azacytidine and the histone deacetylase inhibitor entinostat against de novo AML patients and normal CD34+ bone marrow cells. The MDS and secondary AML patients displayed more extensive aberrant DNA methylation involving thousands of genes than did the normal CD34+ bone marrow cells or de novo AML blasts. Aberrant methylation in MDS and secondary AML tended to affect particular chromosomal regions, occurred more frequently in Alu-poor genes, and included prominent involvement of genes involved in the WNT and MAPK signaling pathways. DNA methylation was also measured at days 15 and 29 after the first treatment cycle. DNA methylation was reversed at day 15 in a uniform manner throughout the genome, and this effect persisted through day 29, even without continuous administration of the study drugs. This trial was registered at www.clinicaltrials.gov as J0443.
Construction and use of gene expression covariation matrix
Authors: Hennetin Jérôme , Pehkonen Petri , Bellis Michel
Published: August 2009

Background

One essential step in the massive analysis of transcriptomic profiles is the calculation of the correlation coefficient, a value used to select pairs of genes with similar or inverse transcriptional profiles across a large fraction of the biological conditions examined. Until now, the choice between the two available methods for calculating the coefficient has been dictated mainly by technological considerations. Specifically, in analyses based on double-channel techniques, researchers have been required to use covariation correlation, i.e. the correlation between gene expression changes measured between several pairs of biological conditions, expressed for example as fold-change. In contrast, in analyses of single-channel techniques scientists have been restricted to the use of coexpression correlation, i.e. correlation between gene expression levels. To our knowledge, nobody has ever examined the possible benefits of using covariation instead of coexpression in massive analyses of single channel microarray results.

Results

We describe here how single-channel techniques can be treated like double-channel techniques and used to generate both gene expression changes and covariation measures. We also present a new method that allows the calculation of both positive and negative correlation coefficients between genes. First, we perform systematic comparisons between two given biological conditions and classify, for each comparison, genes as increased (I), decreased (D), or not changed (N). As a result, the original series of n gene expression level measures assigned to each gene is replaced by an ordered string of n(n-1)/2 symbols, e.g. IDDNNIDID....DNNNNNNID, with the length of the string corresponding to the number of comparisons. In a second step, positive and negative covariation matrices (CVM) are constructed by calculating statistically significant positive or negative correlation scores for any pair of genes by comparing their strings of symbols.

Conclusion

This new method, applied to four different large data sets, has allowed us to construct distinct covariation matrices with similar properties. We have also developed a technique to translate these covariation networks into graphical 3D representations and found that the local assignation of the probe sets was conserved across the four chip set models used which encompass three different species (humans, mice, and rats). The application of adapted clustering methods succeeded in delineating six conserved functional regions that we characterized using Gene Ontology information.
Piecewise multivariate modelling of sequential metabolic profiling data
Authors: Rantalainen Mattias , Cloarec Olivier , Ebbels Timothy MD , Lundstedt Torbjörn , Nicholson Jeremy K , Holmes Elaine , Trygg Johan
Published: August 2009

Background

Modelling the time-related behaviour of biological systems is essential for understanding their dynamic responses to perturbations. In metabolic profiling studies, the sampling rate and number of sampling points are often restricted due to experimental and biological constraints.

Results

A supervised multivariate modelling approach with the objective to model the time-related variation in the data for short and sparsely sampled time-series is described. A set of piecewise Orthogonal Projections to Latent Structures (OPLS) models are estimated, describing changes between successive time points. The individual OPLS models are linear, but the piecewise combination of several models accommodates modelling and prediction of changes which are non-linear with respect to the time course. We demonstrate the method on both simulated and metabolic profiling data, illustrating how time related changes are successfully modelled and predicted.

Conclusion

The proposed method is effective for modelling and prediction of short and multivariate time series data. A key advantage of the method is model transparency, allowing easy interpretation of time-related variation in the data. The method provides a competitive complement to commonly applied multivariate methods such as OPLS and Principal Component Analysis (PCA) for modelling and analysis of short time-series data.
Universal seeds for cDNA-to-genome comparison
Authors: Zhou Leming , Stanton Jonathan , Florea Liliana
Published: August 2009

Background

To meet the needs of gene annotation for newly sequenced organisms, optimized spaced seeds can be implemented into cross-species sequence alignment programs to accurately align gene sequences to the genome of a related species. So far, seed performance has been tested for comparisons between closely related species, such as human and mouse, or on simulated data. As the number and variety of genomes increases, it becomes desirable to identify a small set ofuniversalseeds that perform optimally or near-optimally on a large range of comparisons.

Results

Using statistical regression methods, we investigate the sensitivity of seeds, in particular good seeds, between four cDNA-to-genome comparisons at different evolutionary distances (human-dog, human-mouse, human-chicken and human-zebrafish), and identify classes of comparisons that show similar seed behavior and therefore can employ the same seed. In addition, we find that with high confidence good seeds for more distant comparisons perform well on closer comparisons, within 98–99% of the optimal seeds, and thus represent universal good seeds.

Conclusion

We show for the first time that optimal and near-optimal seeds for distant species-to-species comparisons are more generally applicable to a wide range of comparisons. This finding will be instrumental in developing practical and user-friendly cDNA-to-genome alignment applications, to aid in the annotation of new model organisms.
O-GlcNAc modifications regulate cell survival and epiboly during zebrafish development
Authors: Webster Danielle M , Teo Chin Fen , Sun Yuhua , Wloga Dorota , Gay Steven , Klonowski Kimberly D , Wells Lance , Dougan Scott T
Published: August 2009

Background

The post-translational addition of the monosaccharide O-linked β-N-acetylglucosamine (O-GlcNAc) regulates the activity of a wide variety of nuclear and cytoplasmic proteins. The enzymes O-GlcNAc Transferase (Ogt) and O-GlcNAcase (Oga) catalyze, respectively, the attachment and removal of O-GlcNAc to target proteins. In adult mice, Ogt and Oga attenuate the response to insulin by modifying several components of the signal transduction pathway. Complete loss of ogt function, however, is lethal to mouse embryonic stem cells, suggesting that the enzyme has additional, unstudied roles in development. We have utilized zebrafish as a model to determine role of O-GlcNAc modifications in development. Zebrafish has two ogt genes, encoding six different enzymatic isoforms that are expressed maternally and zygotically.

Results

We manipulated O-GlcNAc levels in zebrafish embryos by overexpressing zebrafish ogt, human oga or by injecting morpholinos against ogt transcripts. Each of these treatments results in embryos with shortened body axes and reduced brains at 24 hpf. The embryos had 23% fewer cells than controls, and displayed increased rates of cell death as early as the mid-gastrula stages. An extensive marker analysis indicates that derivatives of three germ layers are reduced to variable extents, and the embryos are severely disorganized after gastrulation. Overexpression of Ogt and Oga delayed epiboly and caused a severe disorganization of the microtubule and actin based cytoskeleton in the extra-embryonic yolk syncytial layer (YSL). The cytoskeletal defects resemble those previously reported for embryos lacking function of the Pou5f1/Oct4 transcription factor spiel ohne grenzen. Consistent with this, Pou5f1/Oct4 is modified by O-GlcNAc in human embryonic stem cells.

Conclusion

We conclude that O-GlcNAc modifications control the activity of proteins that regulate apoptosis and epiboly movements, but do not seem to regulate germ layer specification. O-GlcNAc modifies the transcription factor Spiel ohne grenzen/Pou5f1 and may regulate its activity.
The evolution of protostome GATA factors: Molecular phylogenetics, synteny, and intron/exon structure reveal orthologous relationships
Authors: Gillis William Q , Bowerman Bruce A , Schneider Stephan Q
Published: August 2009

Background

Invertebrate and vertebrate GATA transcription factors play important roles in ectoderm and mesendoderm development, as well as in cardiovascular and blood cell fate specification. However, the assignment of evolutionarily conserved roles to GATA homologs requires a detailed framework of orthologous relationships. Although two distinct classes, GATA123 and GATA456, have been unambiguously recognized among deuterostome GATA genes, it has been difficult to resolve exact orthologous relationships among protostome homologs. Protostome GATA genes are often present in multiple copies within any one genome, and rapidly evolving gene sequences have obscured orthology among arthropod and nematode GATA homologs. In addition, a lack of taxonomic sampling has prevented a stepwise reconstruction of protostome GATA gene family evolution.

Results

We have identified the complete GATA complement (53 genes) from a diverse sampling of protostome genomes, including six arthropods, three lophotrochozoans, and two nematodes. Reciprocal best hit BLAST analysis suggested orthology of these GATA genes to either the ancestral bilaterian GATA123 or the GATA456 class. Using molecular phylogenetic analyses of gene sequences, together with conserved synteny and comparisons of intron/exon structure, we inferred the evolutionary relationships among these 53 protostome GATA homologs. In particular, we resolved the orthology and evolutionary birth order of all arthropod GATA homologs including the highly divergent Drosophila GATA genes.

Conclusion

Our combined analyses confirm that all protostome GATA transcription factor genes are members of either the GATA123 or GATA456 class, and indicate that there have been multiple protostome-specific duplications of GATA456 homologs. Three GATA456 genes exhibit linkage in multiple protostome species, suggesting that this gene cluster arose by tandem duplications from an ancestral GATA456 gene. Within arthropods this GATA456 cluster appears orthologous and widely conserved. Furthermore, the intron/exon structures of the arthropod GATA456 orthologs suggest a distinct order of gene duplication events. At present, however, the evolutionary relationship to similarly linked GATA456 paralogs in lophotrochozoans remains unclear. Our study shows how sampling of additional genomic data, especially from less derived and interspersed protostome taxa, can be used to resolve the orthologous relationships within more divergent gene families.
Seven new dolphin mitochondrial genomes and a time-calibrated phylogeny of whales
Authors: Xiong Ye , Brandley Matthew C , Xu Shixia , Zhou Kaiya , Yang Guang
Published: August 2009

Background

The phylogeny of Cetacea (whales) is not fully resolved with substantial support. The ambiguous and conflicting results of multiple phylogenetic studies may be the result of the use of too little data, phylogenetic methods that do not adequately capture the complex nature of DNA evolution, or both. In addition, there is also evidence that the generic taxonomy of Delphinidae (dolphins) underestimates its diversity. To remedy these problems, we sequenced the complete mitochondrial genomes of seven dolphins and analyzed these data with partitioned Bayesian analyses. Moreover, we incorporate a newly-developed "relaxed" molecular clock to model heterogenous rates of evolution among cetacean lineages.

Results

The "deep" phylogenetic relationships are well supported including the monophyly of Cetacea and Odontoceti. However, there is ambiguity in the phylogenetic affinities of two of the river dolphin clades Platanistidae (Indian River dolphins) and Lipotidae (Yangtze River dolphins). The phylogenetic analyses support a sister relationship between Delphinidae and Monodontidae + Phocoenidae. Additionally, there is statistically significant support for the paraphyly of Tursiops (bottlenose dolphins) and Stenella (spotted dolphins).

Conclusion

Our phylogenetic analysis of complete mitochondrial genomes using recently developed models of rate autocorrelation resolved the phylogenetic relationships of the major Cetacean lineages with a high degree of confidence. Our results indicate that a rapid radiation of lineages explains the lack of support the placement of Platanistidae and Lipotidae. Moreover, our estimation of molecular divergence dates indicates that these radiations occurred in the Middle to Late Oligocene and Middle Miocene, respectively. Furthermore, by collecting and analyzing seven new mitochondrial genomes, we provide strong evidence that the delphinid genera Tursiops and Stenella are not monophyletic, and the current taxonomy masks potentially interesting patterns of morphological, physiological, behavioral, and ecological evolution.
A strong association of axillary osmidrosis with the wet earwax type determined by genotyping of the ABCC11 gene
Authors: Nakano Motoi , Miwa Nobutomo , Hirano Akiyoshi , Yoshiura Koh-ichiro , Niikawa Norio
Published: August 2009

Background

Two types of cerumen occur in humans: the wet type with brownish, sticky earwax, and the dry type with a lack of or reduced ceruminous secretion. The wet type is common in populations of European and African origin, while the dry type is frequently seen in Eastern Asian populations. An association between axillary odor and the wet-type earwax was first identified approximately 70 years ago. The data were based on a phenotypical analysis of the two phenotypes among the Japanese by a researcher or by self-declaration of the subjects examined, and were not obtained using definite diagnostic methods. Recently, we identified a single-nucleotide polymorphism (SNP; rs17822931) of the ABCC11 gene as the determinant of the earwax types. In the present study, to determine whether the SNP can serve as a diagnostic marker for axillary osmidrosis (AO), we examined genotypes at rs17822931 in 79 Japanese AO individuals. AO was defined here as a clinical condition of individuals with a deep anxiety regarding axillary odor and had undergone the removal of bilateral axillary apocrine glands.

Results

A comparison of the frequencies of genotypes at rs17822931 in the 79 AO individuals and in 161 Japanese from the general population showed that AO was strongly associated with the wet earwax genotype. A total of 78 (98.7%) of 79 AO patients had either the GG or GA genotype, while these genotypes were observed in 35.4% (57/161) of the subjects from the general population (p < 1.1 × 10-24, by Fisher's exact test).

Conclusion

The strong association between the wet-earwax associated ABCC11- genotypes (GG and GA) and AO identified in this study indicates that the genotypes are good markers for the diagnosis of AO. In addition, these results suggest that having the allele G is a prerequisite for the axillary odor expression. In other words, the ABCC11 protein may play a role in the excretory function of the axillary apocrine gland. Together, these results suggest that when an AO individual visiting a hospital is diagnosed with dry-type earwax by ABCC11-genotyping, surgical removal of their axillary glands may not be indicated.
Proteomic-based identification of maternal proteins in mature mouse oocytes
Authors: Zhang Ping , Ni Xiaojian , Guo Ying , Guo Xuejiang , Wang Yufeng , Zhou Zuomin , Huo Ran , Sha Jiahao
Published: August 2009

Background

The mature mouse oocyte contains the full complement of maternal proteins required for fertilization, reprogramming, zygotic gene activation (ZGA), and the early stages of embryogenesis. However, due to limitations of traditional proteomics strategies, only a few abundantly expressed proteins have yet been identified. Our laboratory applied a more effective strategy: one-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis (1D SDS-PAGE) and reverse-phase liquid chromatography tandem mass spectrometry (RP-LC-MS/MS) were employed to analyze the mature oocyte proteome in depth.

Results

Using this high-performance proteomic approach, we successfully identified 625 different proteins from 2700 mature mouse oocytes lacking zona pellucidae. This is the largest catalog of mature mouse oocyte proteins compiled to date. According to their pattern of expression, we screened 76 maternal proteins with high levels of mRNA expression both in oocytes and fertilized eggs. Many well-known maternal effect proteins were included in this subset, including MATER and NPM2. In addition, our mouse oocyte proteome was compared with a recently published mouse embryonic stem cell (ESC) proteome and 371 overlapping proteins were identified.

Conclusion

This proteomics analysis will be a valuable resource to aid in the characterization of important maternal proteins involved in oogenesis, fertilization, early embryonic development and in revealing their mechanisms of action.
Klebsiella pneumoniae triggers a cytotoxic effect on airway epithelial cells
Authors: Cano Victoria , Moranta David , Llobet-Brossa Enrique , Bengoechea José Antonio , Garmendia Junkal
Published: August 2009

Background

Klebsiella pneumoniaeis a capsulated Gram negative bacterial pathogen and a frequent cause of nosocomial infections. Despite its clinical relevance, little is known about the features of the interaction betweenK. pneumoniaeand lung epithelial cells on a cellular level, neither about the role of capsule polysaccharide, one of its best characterised virulence factors, in this interaction.

Results

The interaction betweenKlebsiella pneumoniaeand cultured airway epithelial cells was analysed.K. pneumoniaeinfection triggered cytotoxicity, evident by cell rounding and detachment from the substrate. This effect required the presence of live bacteria and of capsule polysaccharide, since it was observed with isolates expressing different amounts of capsule and/or different serotypes but not with non-capsulated bacteria. Cytotoxicity was analysed by lactate dehydrogenase and formazan measurements, ethidium bromide uptake and analysis of DNA integrity, obtaining consistent and complementary results. Moreover, cytotoxicity of non-capsulated strains was restored by addition of purified capsule during infection. While a non-capsulated strain was avirulent in a mouse infection model, capsulatedK. pneumoniaeisolates displayed different degrees of virulence.

Conclusion

Our observations allocate a novel role toK. pneumoniaecapsule in promotion of cytotoxicity. Although this effect is likely to be associated with virulence, strains expressing different capsule levels were not equally virulent. This fact suggests the existence of other bacterial requirements for virulence, together with capsule polysaccharide.
Genetic mapping of wild introgressions into cultivated peanut: a way toward enlarging the genetic basis of a recent allotetraploid
Authors: Foncéka Daniel , Hodo-Abalo Tossim , Rivallan Ronan , Faye Issa , Sall Mbaye Ndoye , Ndoye Ousmane , Fávero Alessandra P , Bertioli David J , Glaszmann Jean-Christophe , Courtois Brigitte , Rami Jean-Francois
Published: August 2009

Background

Peanut (Arachis hypogaeaL.) is widely used as a food and cash crop around the world. It is considered to be an allotetraploid (2n = 4x = 40) originated from a single hybridization event between two wild diploids. The most probable hypothesis gaveA. duranensisas the wild donor of the A genome andA. ipaënsisas the wild donor of the B genome. A low level of molecular polymorphism is found in cultivated germplasm and up to date few genetic linkage maps have been published. The utilization of wild germplasm in breeding programs has received little attention due to the reproductive barriers between wild and cultivated species and to the technical difficulties encountered in making large number of crosses. We report here the development of a SSR based genetic map and the analysis of genome-wide segment introgressions into the background of a cultivated variety through the utilization of a synthetic amphidiploid betweenA. duranensisandA. ipaënsis.

Results

Two hundred ninety eight (298) loci were mapped in 21 linkage groups (LGs), spanning a total map distance of 1843.7 cM with an average distance of 6.1 cM between adjacent markers. The level of polymorphism observed between the parent of the amphidiploid and the cultivated variety is consistent withA. duranensisandA. ipaënsisbeing the most probable donor of the A and B genomes respectively. The synteny analysis between the A and B genomes revealed an overall good collinearity of the homeologous LGs. The comparison with the diploid and tetraploid maps shed new light on the evolutionary forces that contributed to the divergence of the A and B genome species and raised the question of the classification of the B genome species. Structural modifications such as chromosomal segment inversions and a major translocation event prior to the tetraploidisation of the cultivated species were revealed. Marker assisted selection of BC1F1and then BC2F1lines carrying the desirable donor segment with the best possible return to the background of the cultivated variety provided a set of lines offering an optimal distribution of the wild introgressions.

Conclusion

The genetic map developed, allowed the synteny analysis of the A and B genomes, the comparison with diploid and tetraploid maps and the analysis of the introgression segments from the wild synthetic into the background of a cultivated variety. The material we have produced in this study should facilitate the development of advanced backcross and CSSL breeding populations for the improvement of cultivated peanut.
The association of biomarkers of iron status with peripheral arterial disease in US adults
Authors: Menke Andy , Fernández-Real José Manuel , Muntner Paul , Guallar Eliseo
Published: August 2009

Background

Several studies have examined the association of biomarkers of iron metabolism with measures of carotid artery atherosclerosis, with inconsistent results. Few studies, however, have evaluated the association between biomarkers of iron metabolism and peripheral arterial disease (PAD). The purpose of this study is to examine the association of ferritin and transferrin saturation with PAD.

Methods

Serum ferritin, transferrin saturation, and PAD, defined as having an ankle-brachial blood pressure index <0.9, were measured in 1,631 men and 1,031 postmenopausal women participating in the 1999-2002 National Health and Nutrition Examination Survey (NHANES).

Results

The multivariable adjusted odds ratios (95% confidence interval) for PAD associated with a two-fold increase in serum ferritin and transferrin saturation were 1.18 (1.00-1.41) and 1.45 (0.83-2.51), respectively, for men and 1.04 (0.87-1.25) and 1.55 (0.98-2.45), respectively, for women. After stratifying by cholesterol levels, the multivariable adjusted odds ratios (95% confidence intervals) for PAD associated with a two-fold increase in ferritin and transferrin saturation was 1.04 (0.78-1.39) and 0.73 (0.35-1.50), respectively, for men with total cholesterol <200 mg/dL and 1.30 (0.99-1.72) and 2.59 (0.99-6.78), respectively, for men with total cholesterol ≥ 200 mg/dL (p-value for interaction was 0.58 for ferritin and 0.08 for transferrin saturation). After stratifying by cholesterol levels, the multivariable adjusted odds ratios (95% confidence intervals) for PAD associated with a two-fold increase in ferritin and transferrin saturation was 0.66 (0.41-1.05) and 0.75 (0.44-1.28), respectively, for women with total cholesterol <200 mg/dL, and 1.20 (0.95-1.51) and 2.07 (1.01-4.22), respectively, for women with total cholesterol ≥ 200 mg/dL (p-value for interaction was 0.05 for ferritin and 0.02 for transferrin saturation).

Conclusion

In this large nationally representative sample of men and postmenopausal women, we found a modest association of ferritin and transferrin saturation with PAD, particularly among those with high cholesterol levels.
Epidemiological and some clinical characteristics of neuroblastoma in Mexican children (1996–2005)
Authors: Juárez-Ocaña Servando , Palma-Padilla Virginia , González-Miranda Guadalupe , Siordia-Reyes Alicia Georgina , López-Aguilar Enrique , Aguilar-Martínez Martha , Mejía-Aranguré Juan Manuel , Carreón-Cruz Rogelio , Rendón-Macías Mario Enrique , Fajardo-Gutiérrez Arturo
Published: August 2009

Background

Neuroblastoma (NB) is the principal tumor of the sympathetic nervous system in children under one year of age. The incidence in developed countries is greater than that in developing countries. The aim of this article is to present the epidemiological and some clinical characteristics of Mexican children with NB.

Methods

A population-based, prolective study, with data obtained from the Childhood Cancer Registry of the Instituto Mexicano de Seguro Social. Statistical analysis: The simple frequencies of the variables of the study and the annual average incidence (per 1,000,000 children/years) by age and sex were obtained. The trend was evaluated by calculating the annual percentage of change. The curves of Kaplan-Meyer were employed for the survival rate and the log-rank test was used to compare the curves.

Results

Of a total of 2,758 children with cancer registered during the period from 1996–2005, 72 (2.6%) were identified as having Group IV, defined according to the International Classification of Childhood Cancer. The incidence for NB was 3.8 per 1,000,000 children/year; NB was highest in the group of children under one year of age, followed by the group of children between the ages 1–4 years (18.5 and 5.4 per 1,000,000 children/years, respectively). The male/female ratio was 1.1 and there was no trend toward an increase. The time of diagnosis was 26 days (median), but varied according to the stage at diagnosis. Stages III and IV were presented in 88% of the cases. There was no association between the stage, the age at time of diagnosis, or the histological pattern. The overall five-year survival rate was 64%; the patients with stage I, II, III, or IVs did not die; and the five-year survival rate of cases in Stage IV was 40%.

Conclusion

It is possible that the low incidence of neuroblastoma in Mexican children is due to the difficulty in diagnosing the cases with the best prognosis, some of which could have had spontaneous regression. There was no trend to an increase; the majority of the cases were diagnosed in the advanced stages; and the overall five-years survival rate was similar to that for developed countries.
Histological analysis of low dose NMU effects in the rat mammary gland
Authors: Murray Tessa J , Ucci Angelo A , Maffini Maricel V , Sonnenschein Carlos , Soto Ana M
Published: August 2009

Background

Our objective was to assess the histological changes in mammary glands of the female Wistar-Furth rat as a result of low dose exposure to N-nitrosomethylurea (NMU).

Methods

Groups of 30–40 virgin female rats of between 49–58 days old received a single injection of 10, 20, 30 or 50 mg NMU/kg body weight (BW). A group of 10 control rats received 0.9% NaCl solution only. The formation of palpable mammary gland tumors was assessed weekly and, upon sacrifice at 12, 22 and 25–30 weeks after treatment, we performed a comprehensive histological analysis of all mammary gland lesions and tumors.

Results

Alongside the predicted increase in tumor number and decrease in tumor latency with increasing NMU dose, we observed a number of microscopic lesions and other epithelial abnormalities in the mammary glands for all NMU doses. Two types of non-neoplastic histological changes were observed in rats exposed to 10 or 20 mg NMU/kg BW: namely, (i) an increase in the number of acinar structures often accompanied by secretion into the lumen which is normally associated with pregnancy and lactation, and (ii) an increase in the number of epithelial cells sloughed into the lumen of the epithelial ducts.

Conclusion

This study establishes a baseline for low-dose exposure and defines the histological features in the mammary gland resulting from NMU exposure. Furthermore, this system provides an ideal platform for evaluating the relative susceptibility of animals protected from, or predisposed to, developing cancer through environmental influences.
Prevalence of associated injuries of spinal trauma and their effect on medical utilization among hospitalized adult subjects – a nationwide data-based study
Authors: Chu Dachen , Lee Yi-Hui , Lin Ching-Heng , Chou Pesus , Yang Nan-Ping
Published: August 2009

Background

This study was wanted to investigate the prevalence of concomitant injuries among hospitalized acute spinal trauma patients aged 20 and over and the effects of those injuries on medical utilization in Taiwan.

Methods

Nationwide inpatient datasets of Taiwan's National Health Insurance (NHI) database from between 2000 and 2003 were used. The major inclusion criteria used to select cases admitted due to acute spinal trauma were based on three diagnostic International Classification of Disease, 9th Version (ICD-9) codes items: (1) fracture of vertebral column without mention of spinal cord injury; (2) fracture of vertebral column with spinal cord injury; or (3) spinal cord lesion without evidence of spinal bone injury. To investigate the associated injuries among the eligible subjects, the concomitant ICD-9 diagnosis codes were evaluated and classified into six co-injury categories: (1) head trauma; (2) chest trauma; (3) abdominal trauma; (4) pelvic trauma; (5) upper extremities trauma; (6) lower extremities trauma.

Results

There were 51,641 cases studied; 27.6% of these subjects suffered from neurological deficit, but only 17.3% underwent a surgical procedure for spinal injury. Among them, the prevalence of associated injuries were as follows: head trauma, 17.2%; chest injury, 2.9%; abdominal trauma, 1.5%; pelvic injury or fracture, 2.5%; upper limb fracture, 4.4%; lower limb fracture, 5.9%. The three major locations of acute spinal injury (cervical, thoracic, or lumbar spine) were found to be combined with unequal distributions of associated injuries. By stepwise multiple linear regression, gender, age, location of spinal injury, neurological deficit, surgical intervention and the six combined injuries were identified significantly as associated factors of the two kinds of medical utilization, length of stay (LOS) and direct medical cost. The combinations of acute spinal trauma with lower extremity injury, pelvic injury, chest injury, abdominal injury and upper extremity injury resulted in of the highest utilization of medical resources, the estimated additional LOS being between 4.3 and 1.2 days, and the extra medical cost calculated as being between $1,230 and $320.

Conclusion

The occurrence of associated Injuries among hospitalized acute spinal trauma patients in Taiwan is not uncommon, and results in an obvious effect on medical utilization.
Development and experimental verification of a genome-scale metabolic model for Corynebacterium glutamicum
Authors: Shinfuku Yohei , Sorpitiporn Natee , Sono Masahiro , Furusawa Chikara , Hirasawa Takashi , Shimizu Hiroshi
Published: August 2009

Background

In silicogenome-scale metabolic models enable the analysis of the characteristics of metabolic systems of organisms. In this study, we reconstructed a genome-scale metabolic model ofCorynebacterium glutamicumon the basis of genome sequence annotation and physiological data. The metabolic characteristics were analyzed using flux balance analysis (FBA), and the results of FBA were validated using data from culture experiments performed at different oxygen uptake rates.

Results

The reconstructed genome-scale metabolic model ofC. glutamicumcontains 502 reactions and 423 metabolites. We collected the reactions and biomass components from the database and literatures, and made the model available for the flux balance analysis by filling gaps in the reaction networks and removing inadequate loop reactions. Using the framework of FBA and our genome-scale metabolic model, we first simulated the changes in the metabolic flux profiles that occur on changing the oxygen uptake rate. The predicted production yields of carbon dioxide and organic acids agreed well with the experimental data. The metabolic profiles of amino acid production phases were also investigated. A comprehensive gene deletion study was performed in which the effects of gene deletions on metabolic fluxes were simulated; this helped in the identification of several genes whose deletion resulted in an improvement in organic acid production.

Conclusion

The genome-scale metabolic model provides useful information for the evaluation of the metabolic capabilities and prediction of the metabolic characteristics ofC. glutamicum. This can form a basis for thein silicodesign ofC. glutamicummetabolic networks for improved bioproduction of desirable metabolites.
Shiftwork in the Norwegian petroleum industry: overcoming difficulties with family and social life – a cross sectional study
Authors: Ljoså Cathrine Haugene , Lau Bjørn
Published: August 2009

Background

Continuous shift schedules are required in the petroleum industry because of its dependency on uninterrupted production. Although shiftwork affects health, less is known about its effects on social and domestic life.

Methods

Consequently, we studied these relationships in a sample of 1697 (response rate 55.9%) petroleum workers who worked onshore and offshore for a Norwegian oil and gas company. We also examined the roles of coping strategies and locus of control for handling self-reported problems with social and domestic life. A questionnaire containing scales from the Standard Shiftwork Index and Shiftwork Locus of Control was answered electronically.

Results

In general, only a few participants reported that their shift schedule affected their social and domestic/family life, and several participants had enough time to spend by themselves and with their partner, close family, friends, and children. Despite this general positive trend, differences were found for shift type and individual factors such as locus of control and coping strategies. Internal locus of control was associated positively with all the dependent variables. However, engaging problem-focused coping strategies were associated only slightly with the dependent variables, while disengaging emotion-focused coping strategies were negatively associated with the dependent variables.

Conclusion

Since most participants reported few problems with social and domestic/family life, the availability of more leisure time may be a positive feature of shiftwork in the Norwegian petroleum industry. Locus of control and the use of coping strategies were important for shiftworkers' social and domestic/family life.
3D fluorescent in situ hybridization using Arabidopsis leaf cryosections and isolated nuclei
Authors: Tirichine Leïla , Andrey Philippe , Biot Eric , Maurin Yves , Gaudin Valérie
Published: August 2009

Background

Fluorescent hybridization techniques are widely used to study the functional organization of different compartments within the mammalian nucleus. However, few examples of such studies are known in the plant kingdom. Indeed, preservation of nuclei 3D structure, which is required for nuclear organization studies, is difficult to fulfill.

Results

We report a rapid protocol for fluorescent in situ hybridization (FISH) performed on 3D isolated nuclei and thin cryosectioned leaves of Arabidopsis thaliana. The use of direct labeling minimized treatment steps, shortening the overall procedure. Using image analysis, we measured different parameters related to nucleus morphology and overall 3D structure.

Conclusion

Our work describes a 3D-FISH protocol that preserves the 3D structure of Arabidopsis interphase nuclei. Moreover, we report for the first time FISH using cryosections of Arabidopsis leaves. This protocol is a valuable tool to investigate nuclear architecture and chromatin organization.
Homer regulates calcium signalling in growth cone turning
Authors: Gasperini Robert , Choi-Lundberg Derek , Thompson Michael JW , Mitchell Camilla B , Foa Lisa
Published: August 2009

Background

Homer proteins are post-synaptic density proteins with known functions in receptor trafficking and calcium homeostasis. While they are key mediators of synaptic plasticity, they are also known to function in axon guidance, albeit by mechanisms that are yet to be elucidated. Homer proteins couple extracellular receptors – such as metabotropic glutamate receptors and the transient receptor potential canonical family of cation channels – to intracellular receptors such as inositol triphosphate and ryanodine receptors on intracellular calcium stores and, therefore, are well placed to regulate calcium dynamics within the neural growth cone. Here we used growth cones from dorsal root ganglia, a well established model in the field of axon guidance, and a growth cone turning assay to examine Homer1 function in axon guidance.

Results

Homer1 knockdown reversed growth cone turning from attraction to repulsion in response to the calcium-dependent guidance cues brain derived neurotrophic factor and netrin-1. Conversely, Homer1 knockdown had no effect on repulsion to the calcium-independent guidance cue Semaphorin-3A. This reversal of attractive turning suggested a requirement for Homer1 in a molecular switch. Pharmacological experiments confirmed that the operational state of a calcium-calmodulin dependent protein kinase II/calcineurin phosphatase molecular switch was dependent on Homer1 expression. Calcium imaging of motile growth cones revealed that Homer1 is required for guidance-cue-induced rise of cytosolic calcium and the attenuation of spontaneous cytosolic calcium transients. Homer1 knockdown-induced calcium transients and turning were inhibited by antagonists of store-operated channels. In addition, immunocytochemistry revealed the close association of Homer1 with the store-operated proteins TRPC1 and STIM1 within dorsal root ganglia growth cones.

Conclusion

These experiments provide evidence that Homer1 is an essential component of the calcium signalling repertoire within motile growth cones, regulating guidance-cue-induced calcium release and maintaining basal cytosolic calcium.
Role of STAT1, NF-κB, and C/EBPβ in the macrophage transcriptional regulation of hepcidin by mycobacterial infection and IFN-γ
Authors: Sow Fatoumata B , Alvarez Gail R , Gross Ryan P , Satoskar Abhay R , Schlesinger Larry S , Zwilling Bruce S , Lafuse William P
Published: August 2009

Expression of hepcidin in mouse macrophages is regulated by transcription factors activated by IFN receptors and Toll-like receptors TLR2 and TLR4.

Hepcidin is an antimicrobial peptide involved in regulating iron homeostasis. It is induced by iron overload and decreased by hypoxia and anemia. Hepcidin regulates iron metabolism by inhibiting iron absorption by the duodenum and by inhibiting macrophage iron recycling. Hepcidin is induced in hepatocytes during the acute-phase response by IL-6. Previously, we have shown that hepcidin is not induced in macrophages by IL-6 but is induced by the synergistic interaction of IFN-γ and Mycobacterium tuberculosis infection. In the present study, we examined the pathways involved in inducing macrophage hepcidin expression. We show that TLRs TLR2 and TLR4 and the transcription factor STAT1 are required for induction of hepcidin mRNA. Hepcidin promoter activity is also synergistically induced in RAW264.7 macrophages by IFN-γ and M. tuberculosis. NF-κB and C/CEBP binding sites are required for promoter activity. Binding of NF-κB (p50/p65) to the NF-κB site and STAT1 and C/EBPβ to the C/CEBP site was confirmed by EMSA. Knockdown of STAT1 and C/EBPβ expression in RAW264.7 cells with siRNA plasmids inhibited hepcidin promoter activity induced by IFN-γ and M. tuberculosis. Together, these studies demonstrate that macrophage hepcidin expression is induced by the activation of STAT1 and NF-κB and the induction of C/EBPβ expression.