bluuebunny/crossref_metadata_2025_split huggingface dataset:
Membrane rafts: a potential gateway for bacterial entry into host cells
Authors: Hartlova Anetta , Cerveny Lukas , Hubalek Martin , Krocova Zuzana , Stulik Jiri 
Published: December 2009

ABSTRACTPathogenic bacteria have developed various mechanisms to evade host immune defense systems. Invasion of pathogenic bacteria requires interaction of the pathogen with host receptors, followed by activation of signal transduction pathways and rearrangement of the cytoskeleton to facilitate bacterial entry. Numerous bacteria exploit specialized plasma membrane microdomains, commonly called membrane rafts, which are rich in cholesterol, sphingolipids and a special set of signaling molecules which allow entry to host cells and establishment of a protected niche within the host. This review focuses on the current understanding of the raft hypothesis and the means by which pathogenic bacteria subvert membrane microdomains to promote infection.
Initiation of malignancy by duodenal contents reflux and the role of ezrin in developing esophageal squamous cell carcinoma
Authors: Ling Zhi‐Qiang , Mukaisho Ken‐ichi , Yamamoto Hiroto , Chen Kuan‐Hao , Asano Shinji , Araki Yoshio , Sugihara Hiroyuki , Mao Wei‐Min , Hattori Takanori 
Published: December 2009

(Cancer Sci 2010; 101: 624–630)Gastroesophageal reflux has recently been implicated as a causative factor in upper aerodigestive tract carcinogenesis. Esophageal squamous cell carcinomas (ESCCs) have developed in duodenal‐content reflux animals without any known carcinogen present. We established a cell line, designated ESCC‐DR, from a thoracic metastatic tumor in a reflux animal. To gain insight into the genomic alterations associated with duodenal content reflux‐induced carcinogenesis, we first performed comparative genomic hybridization using an Agilent rat 244K array in ESCC‐DR and identified many chromosomal gains and losses. Of the many genes identified, we detected an interesting ezrin amplicon that has been recently reported in human ESCC. Ezrin, which cross‐links the cytoskeleton and plasma membrane, is involved in the growth and metastatic potential of cancer cells. Overexpression of ezrin protein in ESCC‐DR was confirmed by Western blotting. We also compared ezrin protein expression levels and patterns in hyperplastic, dysplastic, ESCC, and metastatic sites developed in two distinct reflux models using immunohistochemistry. Immunohistochemical staining of ezrin revealed overexpression in the nucleus, and the cytoplasm as well as plasma membrane of ESCC cells. Phosphorylated ERM (ezrin, radixin, moesin) was expressed at the leading edge, or invasive front, of larger metastatic sites. Taken together, duodenal reflux has a great potential for initiating malignancy, and thus likely plays a role in development of ESCC. Ezrin probably influences the growth and invasiveness of ESCC cells, and phosphorylation is only required in metastatic behavior of tumor cells at the leading edge and invasive front.
Identification of increased NBS1 expression as a prognostic marker of squamous cell carcinoma of the oral cavity
Authors: Hsu Dennis Shin‐Shian , Chang Shyue‐Yih , Liu Chung‐Ji , Tzeng Cheng‐Hwai , Wu Kou‐Juey , Kao Jung‐Yie , Yang Muh‐Hwa 
Published: December 2009

Oral squamous cell carcinoma (OSCC) is one of the most prevalent cancers worldwide; however, accurate molecular markers to predict its prognosis are still limited. We previously demonstrated that overexpression of the DNA double‐strand break repair protein NBS1 is a prognostic marker of advanced head and neck squamous cell carcinoma (HNSCC). Therefore, we aimed to investigate the feasibility of using NBS1 as a biomarker in OSCC. In this study, we enrolled 148 OSCC for immunohistochemical (IHC) and clinical analysis. Data from 58 advanced non‐oral‐cavity HNSCC (NO‐HNSCC) cases were also included for comparison due to the biological and clinical discrepancy between OSCC and HNSCC originated from the other sites (e.g. pharynx or larynx). First, we validated the NBS1 IHC results by real‐time RT‐PCR analysis, and an excellent correlation between the results of these two assays confirmed the reliability and robustness of IHC procedures and interpretation. NBS1 overexpression was an independent prognostic marker in both OSCC and NO‐HNSCC cases. In OSCC, the prognostic significance of NBS1 was shown regardless of T stage and lymph node status. Increased NBS1 expression correlated with advanced T stage and recurrence/metastasis. NBS1 overexpression correlated with the phosphorylation levels of Akt and its downstream target mammalian target of rapamycin (mTOR). These results clearly illustrate the expression profile of NBS1 in OSCC and NO‐HNSCC, and highlight the role of NBS1 in HNSCC irrespective of the primary sites. It also indicates the practicability of application of NBS1 as a marker in OSCC.(Cancer Sci 2010; 101: 1029–1037)
Subsidence history from a backstripping analysis of the Permo‐Mesozoic succession of the Central Southern Alps (Northern Italy)
Authors: Berra Fabrizio , Carminati Eugenio 
Published: December 2009

ABSTRACTSeven tectonic subsidence curves, based on outcrop data, have been calculated in order to constrain the geodynamic evolution of the Permian–Mesozoic sedimentary succession (up to 10 km thick) of the Central Southern Alps basin (Italy). The analysis of the tectonic subsidence curves, covering a time span of about 200 Ma, allowed us to quantify the subsidence rates, to document the activity of syndepositional fault systems and calculate their slip rates. Different stages, in terms of duration and magnitude of subsidence‐uplift trends, have been identified in the evolution of the basin. The fault activity, reconstructed by comparing subsidence curves from adjacent sectors, resulted as highly variable both temporally and spatially. Strike‐slip tectonics was coeval to Permian sedimentation, as suggested by the strong differences in the subsidence rates in the sections. The evolution and subsidence rates suggest a continental shelf deposition from Early Triassic to Carnian, when subsidence came to a stop. A rapid resumption of subsidence is observed from the Norian, with a subsidence pulse in the Late Norian, followed by the regional uplift, in the Late Rhaetian. The following Early Jurassic subsidence is characterized by tectonic subsidence similar to that of the Norian. The Norian and Early Jurassic pulses were characterized by the highest slip rates along growth faults and are identified as two distinct tectonic events. The Norian–Rhaetian event is tentatively related to transtensional tectonics whereas the Early Jurassic event is related to crustal extension. The Early Jurassic subsidence records a shift in space an time of the beginning of the extensional stage, from Late Hettangian to the east to Late Pliensbachian–Toarcian to the west. From the Toarcian to the Aptian, the curves are compatible with regional thermal subsidence, later followed (Albian–Cenomanian) by uplift pulses in a retrobelt foreland basin (from Cenomanian onward).
Survival of plants of common sainfoin (Onobrychis viciifolia Scop.) in competition with two companion grass species
Authors: Liu Z. , Baines R. N. , Lane G. P. F. , Davies W. P. 
Published: December 2009

AbstractA 2‐year experiment on competition between sainfoin (Onobrychis viciifolia Scop.), meadow fescue (Festuca pratensis) and tetraploid perennial ryegrass (Lolium perenne) was conducted using plants grown in plastic containers outdoors. Root and shoot systems of sainfoin and the grasses were separated in order to investigate full and no competition of root and shoots, at two planting ratios (0·33 grass:0·66 sainfoin and 0·66 grass:0·33 sainfoin). Survival of sainfoin plants was lower at the higher grass:sainfoin ratio. More sainfoin plants died in the winter than during the growing season. Root competition had no effect on survival of sainfoin plants, but shoot competition reduced survival of sainfoin plants during one growing season. Companion grass species had no effect on survival of sainfoin plants, except in the first winter, when fewer sainfoin plants survived when grown with meadow fescue than perennial ryegrass.
Reseeding Mediterranean dryland cereal fallows using Stipa lagascae R. & Sch.: influence of cutting regime during the establishment phase
Authors: Visser M. , Ouled Belgacem A. , Neffati M. 
Published: December 2009

AbstractWhen grass species are used to reseed depleted drylands, grazing is often prescribed during the establishment phase. Total protection from grazing often leads to the presence of persistent weed species and is hard to accept by land users keen to graze reseeded land as soon as possible. The particular case of reseeding arid Mediterranean cereal fallows with one native grass species, Stipa lagascae (Stipa), in Tunisia was tested. Seedlings, derived from two different seed sources (selected and bulk), and volunteer annual weed species underwent four different cutting treatments to ground level (early cut, late cut, early and late cuts and no cuts). No effect of any of the treatments on seedling survival or dry matter mass of Stipa seedlings was found. It was concluded that Stipa seedlings are indifferent to the presence of annual weed species and can tolerate more than one cut during the year of establishment. In the context of the study, early grazing of reseeded fallows is worth investigating further.
Influence of different forage grasses on nitrate capture and leaching loss from a pumice soil
Authors: Popay A. J. , Crush J. R. 
Published: December 2009

AbstractNitrogen (N) uptake and loss in leachate from a pulse of 15N‐labelled synthetic cow urine applied to a pumice soil were compared in a glasshouse lysimeter experiment among the grass species, Agrostis capillaris, Dactylis glomerata, Phalaris aquatica, Lolium multiflorum, L. perenne and a L. multiflorum/A. capillaris mixture. In addition, four L. perenne treatments investigated the effect of infection by Neotyphodium lolii strains. Leachate volumes and leachate nitrate concentrations were measured. At final harvest 24 weeks after sowing, dry matter (DM) mass of shoots and roots, plant N and 15N contents, soil residual mineral N, and root diameters and lengths were measured. Endophyte had no effect on plant or nitrate variables. Lysimeters planted with L. perenne (pooled endophyte treatments) leached 48 mg of NO3‐N compared with <3 mg N for the other grasses. Recovery of 15N was highest in A. capillaris (0·99), followed by D. glomerata and P. aquatica (0·89), the L. multiflorum/A. capillaris mixture (0·87), L. multiflorum (0·60) and L. perenne (0·44). Low 15N recoveries and high leaching losses from L. perenne were associated with low plant and root masses of DM and low rooting depth. High aerial mass of DM, root systems extending below 20 cm and high root masses of DM in lysimeters with A. capillaris, P. aquatica and D. glomerata contributed to a high rate of nitrate interception by these species and low leachate losses. The L. multiflorum/A. capillaris mixture was intermediate between the two species for most of the variables measured.
harrow: new Drosophila hAT transposons involved in horizontal transfer
Authors: Mota N. R. , Ludwig A. , Da Silva Valente V. L. , Loreto E. L. S. 
Published: December 2009

AbstractIn this study we characterize the transposable elements harrow, which belong to the hAT superfamily of DNA transposons. Searches for harrow sequences were performed in 65 Drosophilidae species, mainly representing Neotropical and cosmopolitan groups from the genus Drosophila. The nucleotide divergence among elements found in these species suggests that harrow sequences could be clustered in a subfamily. The patchy distribution throughout the genus Drosophila and the high similarity presented between all harrow sequences indicate that horizontal transfer could play a major role in the evolution of harrow elements. The results obtained suggest an evolutionary scenario in which harrow would have undergone multiple horizontal transfer events in the Neotropics, involving D. tripuncatata, D. mojavensis (Subgenus Drosophila) and several species of the willistoni and saltans groups (subgenus Sophophora).
Analysis of Rickettsia typhi‐infected and uninfected cat flea (Ctenocephalides felis) midgut cDNA libraries: deciphering molecular pathways involved in host response to R. typhi infection
Authors: Dreher‐Lesnick S. M. , Ceraul S. M. , Lesnick S. C. , Gillespie J. J. , Anderson J. M. , Jochim R. C. , Valenzuela J. G. , Azad A. F. 
Published: December 2009

AbstractMurine typhus is a flea‐borne febrile illness that is caused by the obligate intracellular bacterium, Rickettsia typhi. The cat flea, Ctenocephalides felis, acquires R. typhi by imbibing a bloodmeal from a rickettsemic vertebrate host. To explore which transcripts are expressed in the midgut in response to challenge with R. typhi, cDNA libraries of R. typhi‐infected and uninfected midguts of C. felis were constructed. In this study, we examined midgut transcript levels for select C. felis serine proteases, GTPases and defence response genes, all thought to be involved in the fleas response to feeding or infection. An increase in gene expression was observed for the serine protease inhibitors and vesicular trafficking proteins in response to feeding. In addition, R. typhi infection resulted in an increase in gene expression for the chymotrypsin and rab5 that we studied. Interestingly, R. typhi infection had little effect on expression of any of the defence response genes that we studied. We are unsure as to the physiological significance of these gene expression profiles and are currently investigating their potential roles as it pertains to R. typhi infection. To our knowledge, this is the first report of differential expression of flea transcripts in response to infection with R. typhi.
Inferring spatial structure from time‐series data: using multivariate state‐space models to detect metapopulation structure of California sea lions in the Gulf of California, Mexico
Authors: Ward Eric J. , Chirakkal Haridas , González‐Suárez Manuela , Aurioles‐Gamboa David , Holmes Elizabeth E. , Gerber Leah 
Published: December 2009

Summary1. Understanding spatial structure and identifying subpopulations are critical for estimating population growth rates and extinction risk, and as such essential for effective conservation planning. However, movement and spatiotemporal environmental data are often unavailable, limiting our ability to directly define subpopulations and their level of asynchrony.2. This study applies a recently developed statistical technique using time‐series analysis of abundance data to identify subpopulations. The approach uses multivariate state‐space models and Akaike’s Information Criterion‐based model selection to quantify the data support for different subpopulation numbers and configurations. This technique is applied to the population of California sea lionsZalophuscalifornianusin the Gulf of California, Mexico, distributed across 13 breeding sites.3. The abundance of California sea lions in the Gulf of California has declined over the last decade, though not all areas have been equally affected. In light of this variation, it is important to understand the population structure to ensure accurate viability assessments and effective management.4. Our data support the hypothesis that the Gulf of California sea lion population has four subpopulations, each with 2–5 breeding sites. The dynamics between several adjacent subpopulations were correlated, suggesting that they experience similar environmental variation. For each subpopulation, we estimated long‐term growth rates, as well as the environmental and observation variation.5. For most of the subpopulations, our estimates of growth rates were considerably lower than those previously reported. In addition, we found considerable variability across subpopulations in their projected risk of severe decline over the next 50 years.6. Synthesis and applications. We illustrate a new multivariate state‐space modelling technique that uses time series of abundance to quantify the data support for different subpopulation configurations. Our analysis of the California sea lion population in the Gulf of California indicates that the population is spatially structured into four subpopulations, each exhibiting distinct risks of extinction. Based on our results, we recommend that conservation and management efforts in the Gulf of California focus on the two subpopulations with high probabilities of extinction within the next 50 years (Northern Midriff, Southern Midriff). Multivariate state‐space models provide a practical approach to determine the spatial structure of virtually any species; they may be particularly useful for species of conservation concern for which data on dispersal and environmental drivers are likely to be scarce.
Biogeography and diversification of the Pacific ant genus Lordomyrma Emery
Authors: Lucky Andrea , Sarnat Eli M. 
Published: December 2009

AbstractAim  This study addresses the origins of terrestrial biodiversity of the Fijian islands using the ant genus Lordomyrma (Hymenoptera: Formicidae: Myrmicinae) as a model system. We derive the evolution of the genus and determine its closest extra‐Fijian relatives from geological data, molecular phylogenetic reconstruction and divergence estimates.Location  Ant taxa were sampled in the Southwest Pacific, Melanesia, Southeast Asia, Australia and mainland China.Methods  Phylogeny and divergence estimates of the ant genus Lordomyrma based on four nuclear genes (28S, ArgK, LW Rh, CAD) plus data on Indo‐Pacific geological history are used to address current hypotheses regarding the origins of the Fijian biota.Results  The genus Lordomyrma probably originated in mainland Asia, with subsequent colonization of Australia and the Pacific. The Fijian Lordomyrma clade is monophyletic, and originated c. 8.8 Ma, when it diverged from a sister group in Papua New Guinea.Main conclusions  The colonization of Fiji by Lordomyrma is probably a result of long‐distance dispersal from New Guinea, possibly aided by island hopping across the Vitiaz Arc. The timeline of diversification in Lordomyrma is broadly congruent with the Miocene fragmentation of the Vitiaz Arc and the Pliocene emergence of Vanua Levu. The biotic shuttle hypothesis, which posits ‘Eua Island as the source of Fijian endemics, is rejected based on the sister relationship of Fiji and New Guinea lineages, as well as on the Miocene submergence of the terrane below sea level. The diversity of Fijian Lordomyrma results from the radiation of a single lineage, which diverged from a New Guinea sister group. The genus appears to have originated in Asia rather than in Australia.
Striking Activation of NALT and Nasal Passages Lymphocytes Induced by Intranasal Immunization with Cry1Ac protoxin
Authors: Rodriguez‐Monroy M. A. , Moreno‐Fierros L. 
Published: December 2009

AbstractCry1Ac protoxin from Bacillus thuringiensis is a potent mucosal immunogen and adjuvant. When delivered intranasally (i.n.) Cry1Ac elicits significant antibody response and is able to improve vaccination against Naegleria fowleri infection, but the functional effects occurring in nasal lymphocytes when this protein is administered alone have not been determined. Here, we investigated the effects of i.n. immunization with Cry1Ac on antibody production, lymphocyte activation and cytokine production in lymphocytes from nasal‐associated lymphoid tissue (NALT) and nasal passages (NP). Our results show that i.n. immunization with Cry1Ac induced significant specific IgA and IgG cell responses, especially in NP. Besides, it increased the proportion of lymphocytes expressing the activation markers CD25 and CD69 in both nasal tissues, but differently. CD25 was increased in B cells along with CD4 and CD8 T cells from NALT and NP, while CD69 was increased in B cells from both tissues but only in CD4 T cells from NP. Finally, we found that Cry1Ac augmented especially a Th2 profile of cytokines, as the proportion of T cells that spontaneously produced IL‐4, IL‐5 and IL‐10 was increased and this effect was higher in NP than in NALT. These data contribute to explain the potent immunogenicity of Cry1Ac via i.n. route.
Antitumour Response of a Double Mutant of Staphylococcal Enterotoxin C2 with the Decreased Affinity for MHC Class II Molecule
Authors: Cheng X. , Cao P. , Ji X. , Lu W. , Cai X. , Hu C. , Wang Z. , Zhang S. 
Published: December 2009

AbstractStaphylococcal enterotoxin C2 (SEC2) is one of the most potent known activators of human T lymphocytes, and recombinant SEC2 shows promising clinical values, but SEC2 can cause food poisoning and toxic shock syndrome in vivo. In this study, site‐directed mutagenesis has been used to introduce alanine substitutions at Phe144 and Leu45 in the molecule. The mutant genes were cloned and expressed, and the corresponding proteins were purified by nickel agarose affinity chromatography. We found that the SEC2 mutant proteins could stimulate the proliferation of human peripheral blood lymphocytes and inhibit the growth of tumour cells as native SEC2. Furthermore, flow cytometry assay showed that mSEC2(F44A, L45A) drastically reduced the ability of the toxin to bind to MHC class II. Physiological parameters revealed that mSEC2(F44A, L45A) reduced significantly rat temperature compared with native SEC2 in vivo. Our results clearly suggest that this genetically modified SEC2 protein is less toxic and justifies its further development as a new, safer antitumour superantigen to prevent SEC2 intoxication.
IL‐23 in the Pathogenesis of Rheumatoid Arthritis
Authors: Paradowska‐Gorycka A. , Grzybowska‐Kowalczyk A. , Wojtecka‐Lukasik E. , Maslinski S. 
Published: December 2009

AbstractInterleukin‐23 (IL‐23) is a heterodimeric cytokine belonging to the IL‐6/IL‐12 family that plays a key role in several of autoimmune and inflammatory disorders. This family contains the 34 type I cytokine receptor chains and 27 ligands, which share structural and functional similarities, but on the other hand they display distinct roles in shaping Th cells responses. IL‐12 family cytokines have not only proinflammatory effects but they also promote inflammatory responses. IL‐23 is composed of the p40 subunit in common with IL‐12, and with a unique p19 subunit. IL‐23 binding to an IL‐23 receptor expressed on dendritic cells, macrophages and monocytes triggers the activation of Jak2 and Tyk2, which in turn phosphorylates STAT1, STAT3, STAT4 and STAT5 as well as induce formation of STAT3‐STAT4 heterodimers. IL‐23 is one of the essential factors required for the survival and/or expansion of Th17 cells, which produce IL‐17, IL‐17F, IL‐6 and TNF‐α. Th17 cells stimulated by the IL‐23 promote osteoclastogenesis through production of IL‐17, which induce receptor activator of NF‐kappa B ligand on mesenchymal cells. The IL‐23‐IL‐17 axis includes Th17 cells and plays a key role in the development of autoimmune arthritis.