bluuebunny/crossref_metadata_2025_split huggingface dataset:
Faster returns on ‘leaf economics’ and different biogeochemical niche in invasive compared with native plant species
Authors: PENUELAS JOSEP , SARDANS JORDI , LLUSIÀ JOAN , OWEN SUSAN M. , CARNICER JOFRE , GIAMBELLUCA THOMAS W. , REZENDE ENRICO L. , WAITE MASHURI , NIINEMETS ÜLO 
Published: August 2009

AbstractPlant‐invasive success is one of the most important current global changes in the biosphere. To understand which factors explain such success, we compared the foliar traits of 41 native and 47 alien‐invasive plant species in Oahu Island (Hawaii), a location with a highly endemic flora that has evolved in isolation and is currently vulnerable to invasions by exotic plant species. Foliar traits, which in most cases presented significant phylogenetic signal, i.e. closely related species tended to resemble each other due to shared ancestry, separated invasive from native species. Invasive species had lower leaf mass per area and enhanced capacities in terms of productivity (photosynthetic capacity) and nutrient capture both of macro‐ (N, P, K) and microelements (Fe, Ni, Cu and Zn). All these differences remain highly significant after removing the effects of phylogenetic history. Alien‐invasive species did not show higher efficiency at using limiting nutrient resources, but they got faster leaf economics returns and occupied a different biogeochemical niche, which helps to explain the success of invasive plants and suggests that potential increases in soil nutrient availability might favor further invasive plant success.
Polyclonal expansion of cervical cytobrush‐derived T cells to investigate HIV‐specific responses in the female genital tract
Authors: Bere Alfred , Denny Lynette , Burgers Wendy A. , Passmore Jo‐Ann S. 
Published: August 2009

SummaryHuman immunodeficiency virus (HIV) ‐specific T‐cell responses are detectable in the female genital tract of HIV‐infected women but little is known about their frequency or the factors that influence their detection. We investigated the feasibility of polyclonal in vitro expansion of cervical cytobrush‐derived T cells to investigate HIV‐specific responses in the female genital tract in HIV‐infected women. Cytobrush‐derived cervical cells were isolated from 22 HIV‐infected women and expanded with anti‐CD3 and recombinant interleukin‐2. Cervical T‐cell lines were investigated for Gag‐specific responses by interferon‐γ ELISPOT and compared with those detected in matched blood samples. Cervical T‐cell lines were established from 16/22 (72·7%) participants. Although the absolute number of CD3± cells recovered after expansion was positively associated with the number of cells isolated ex vivo (P = 0·01; R = 0·62), we observed a significant negative correlation between fold expansion and ex vivo cell number (P = 0·004; R = −0·68). We show that both the magnitude (P = 0·002; R = 0·7) and specific Gag regions targeted by cervical T‐cell lines (P < 0·0001; R = 0·5) correlated significantly with those detected in blood. With one exception, cervical interferon‐γ T‐cell responses to Gag were detected only in HIV‐infected women with blood Gag‐specific response > 1000 spot‐forming units/106 cells. We conclude that cervical Gag‐specific T‐cell responses in expanded lines are most easily detectable in women who have corresponding high‐magnitude Gag‐specific T‐cell responses in blood.
Toll‐like receptors – sentries in the B‐cell response
Authors: Bekeredjian‐Ding Isabelle , Jego Gaetan 
Published: August 2009

SummaryToll‐like receptors (TLR) play a central role in the initiation of the innate immune response to pathogens. Upon recognition of molecular motifs specific for microbial molecules TLR mediate pro‐inflammatory cytokine secretion and enhance antigen presentation; in B cells they further promote expansion, class switch recombination and immunoglobulin secretion. As a result of their adjuvant properties, TLR ligands have become an integral component of antimicrobial vaccines. In spite of this, little is known of the direct effects of TLR engagement on B‐lymphocyte function. The scope of this review is to outline the differences in TLR expression and reactivity in murine and human B‐cell subsets and to provide an overview of the currently available literature. We will further discuss the possible roles of TLR in regulating B‐cell effector functions and shaping antibody‐mediated defence against microbial pathogens in vivo.
Administration of polysaccharides from Antrodia camphorata modulates dendritic cell function and alleviates allergen‐induced T helper type 2 responses in a mouse model of asthma
Authors: Liu Ko‐Jiunn , Leu Sy‐Jye , Su Ching‐Hua , Chiang Bor‐Luen , Chen Yi‐Lien , Lee Yueh‐Lun 
Published: August 2009

SummaryAsthma is a chronic disease characterized by airway inflammation caused by the dysregulated production of cytokines secreted by allergen‐specific type 2 T helper (Th2) cells. Antrodia camphorata is a commonly used fungus in Asian folk medicine, and A. camphorata polysaccharides are reported to possess anti‐cancer activities. In this study, the immunomodulatory effects of purified fractionated polysaccharides (GF2) from A. camphorata on dendritic cells (DCs) and their potential preventive effects against ovalbumin (OVA) ‐induced asthma were investigated. In the presence of GF2, lipopolysaccharide (LPS) ‐activated DCs exhibited up‐regulated expression of major histocompatibility complex (MHC) class II and co‐stimulatory molecules, as well as enhanced interleukin‐10 (IL‐10) and IL‐12 production. GF2 treatment on LPS‐activated DCs suppressed naïve CD4+ T‐cell proliferation and Th2 cell polarization with IL‐10 production in an allogeneic mixed lymphocyte reaction. In animal experiments, a high dose of GF2 efficiently reduced expression levels of OVA‐specific immunoglobulin G1 (IgG1) and IgE. However, lower doses of GF2 significantly enhanced OVA‐specific IgG2a production. Our data also showed that administration of GF2 dose‐dependently inhibited the development of airway hyperresponsiveness, airway eosinophilia and Th2 responses. OVA‐specific CD4+ T cells from higher doses of GF2‐treated mice had significantly lower proliferative capacities compared with control mice. Moreover, treatment with GF2 significantly increased the high levels of IL‐10 and low levels of interferon‐γ produced by T cells. Taken together, these data indicate that administration of A. camphorata polysaccharides (GF2) may have therapeutic potential when used as an adjuvant for the immunomodulatory treatment of allergic asthma.
Contributions on cardiac physiology in Diplopoda (Myriapoda)
Authors: HERTEL WIELAND 
Published: August 2009

AbstractInvestigations into cardiac physiology in Myriapoda are rare, but heart beat generation is not considered to be uniform throughout this taxon. Although cardiac automatism in Chilopoda is neurogenic, superimposed onto a myogenic automatism, the present study reveals, on the basis of electrophysiological experiments including electrocardiograms and the first intracellular recordings from dorsal vessel muscle cells of Archispirostreptus gigas Peters, 1855 (Diplopoda: Spirostreptida, Spirostreptidae), that heartbeat generation in Diplopoda is clearly myogenic. Experiments with tetrodotoxin confirm this result, and also show that proctolin, acetylcholine and octopamine have no effect. The results are discussed from the perspective of comparative cardiac physiology in arthropods.
A potential function for oocyte apoptosis in unmated Nauphoeta cinerea
Authors: BARRETT EMMA L.B. , MOORE ALLEN J. , MOORE PATRICIA J. 
Published: August 2009

AbstractStarvation and enforced virginity induce apoptosis (programmed cell death) in the oocytes of female cockroaches of Nauphoeta cinerea, yet the life‐history outcome differs among fed and starved virgins. Consistent with the hypothesis that oocytes are absorbed to reallocate resources, apoptosis is followed by an increase in future reproduction and longevity in starved virgins. However, apoptosis induction by enforced virginity in fed females results in reduced fecundity and longevity. It is predicted that this life‐history outcome occurs because oocyte apoptosis under these conditions is not part of an adaptive reproductive strategy but simply is the result of cellular ageing and clearance to maintain reproductive synchrony. In the present study, reproductive and somatic allocation are examined over time to test whether resources are recouped by the fat body, reinvested in reproduction or lost altogether when apoptosis is associated with enforced virginity. To assay reproductive investment, the number of ovarioles is counted, apoptosis levels are analysed and the size of all oocytes within the vitellaerium is measured. To assay somatic investment, dry fat body mass is measured. In conjunction with apoptosis, the number of ovarioles declines, whereas the size of surviving oocytes increases. By contrast to the cellular ageing hypothesis, apoptosis associated with enforced virginity appears to be adaptive if resources from sacrificed oocytes are recycled into the survivors to maintain the quality of ageing oocytes. This reinvestment in current reproduction may trade‐off with future reproductive capacity.
Diapause‐inducing signals prolong nymphal development in the two‐spotted spider mite Tetranychus urticae
Authors: SUZUKI TAKESHI , TAKEDA MAKIO 
Published: August 2009

AbstractFemale two‐spotted spider mite Tetranychus urticae are grown under different photoperiods and the photoperiodic regulation of diapause is examined. The photoperiodic response curve for diapause induction was of the long day–short day type, with critical day lengths (CDLs) of 2 and 12.5 h; diapause was induced between these CDLs. The preimaginal period is significantly longer in diapausing females than in non‐diapausing females; moreover, a significant positive correlation is detected between diapause incidence and deutonymphal period. Diapause incidence is high when long‐night photoperiods are applied against a background of continuous darkness in the stages including the deutonymph; this stage appears to be the most sensitive to photoperiod. These observations suggest that diapause‐inducing conditions inhibit nymphal development, particularly in the deutonymphal stage when photoperiodic time measurement for determination of reproduction or diapause is carried out.
Loss of human β‐defensin 1, 2, and 3 expression in oral squamous cell carcinoma
Authors: Joly S. , Compton L. M. , Pujol C. , Kurago Z. B. , Guthmiller J. M. 
Published: August 2009

Introduction:  Human β‐defensins (HBDs) are cationic, antimicrobial peptides produced by epithelial cells and involved in various aspects of the innate and acquired immune responses. They are expressed by oral tissues as constitutive and inducible genes. Recently, single nucleotide polymorphisms (SNPs) of β‐defensins have been correlated with increased susceptibility to certain diseases. Studies have reported altered expression of β‐defensins in cancers suggesting their involvement in carcinogenesis. The purpose of this study was to evaluate the regulation of HBD‐1 (also published as DEFB1), HBD‐2 (DEFB4) and HBD‐3 (DEFB103A) (http://www.genenames.org/index.html) and HBD‐1 SNPs in oral squamous cell carcinoma cell lines (OSCC) and healthy gingival keratinocytes.Methods:  β‐defensin expression was quantitatively assessed using real‐time polymerase chain reactions in OSCC and control cell lines after exposure to interleukin‐1β, tumor necrosis factor‐α, and interferon‐γ. Control data were obtained in a previous study. DNA from 19 OSCC cell lines and 44 control subjects were extracted and the HBD‐1 region spanning the 5′ untranslated region to the first intron was sequenced and analysed for SNP identification and distribution.Results:  HBD‐1 and HBD‐2 basal messenger RNA expression were significantly lower in OSCC. In addition, the ability to be induced was significantly reduced in OSCC for all three β‐defensins. Four HBD‐1 SNPs were differentially distributed between cancer and control populations. Genotype distribution at the HBD‐1 locus also suggested loss of heterozygosity in OSCC.Conclusions:  The genetic variation observed in OSCC compared with that in control cell lines may account for differences in β‐defensin expression. These results suggest a putative role for β‐defensins in carcinogenesis and indicate that β‐defensins may be useful markers of OSCC.
fimA genotypes and PFGE profile patterns in Porphyromonas gingivalis isolates from subjects with periodontitis
Authors: Perez‐Chaparro P. J. , Rouillon A. , Minet J. , Lafaurie G. I. , Bonnaure‐Mallet M. 
Published: August 2009

Background and objectives:  Porphyromonas gingivalis is frequently identified to type by evaluation of fimA polymorphisms and less often by pulsed‐field gel electrophoresis (PFGE) because of the technical intricacies of PFGE. To compare these techniques, we genotyped P. gingivalis clinical isolates as to (i) their fimA type and (ii) their whole genome restriction profile (PFGE analysis).Material and methods:  Thirty‐two P. gingivalis strains were isolated from 16 unrelated periodontitis patients. Two strains were isolated from each patient. Strains were subjected to a fimA‐typing polymerase chain reaction (PCR) assay. Strains that could not be typed by PCR were submitted to sequencing of the entire fimA gene. The PFGE profiles of clinical strains were compared using bioinformatic analysis.Results:  Seven of the 32 isolates were not typeable by PCR and so their entire fimA gene was sequenced. The sequencing identified each strain as belonging to a single fimA type. In one case, sequencing of the fimA gene did not agree with the result obtained using fimA PCR typing. With the exception of one patient, each patient presented isolates bearing the same fimA type. However, in three patients, isolates with the same fimA type presented different PFGE pulsotypes.Conclusion:  The P. gingivalis typing using fimA PCR has limitations in typeability and discriminatory power. A typing technique for P. gingivalis that is easy to perform but that presents adequate typeability and discriminatory power is needed if we want to better understand the epidemiology of periodontal disease.
Contribution of cell surface protein antigen c of Streptococcus mutans to platelet aggregation
Authors: Matsumoto‐Nakano M. , Tsuji M. , Inagaki S. , Fujita K. , Nagayama K. , Nomura R. , Ooshima T. 
Published: August 2009

Introduction:  Streptococcus mutans is considered to be one of the pathogens that cause infective endocarditis. The purpose of the present study was to examine the properties of S. mutans with regard to platelet aggregation by focusing on its high molecular protein antigen c (PAc).Methods:  The platelet aggregation properties of six clinical strains and one isogenic mutant strain of S. mutans were analysed using an aggregometer and confocal microscopy, as well as with an inhibition assay of platelet aggregation using anti‐PAc serum.Results:  S. mutans strains with PAc expression induced platelet aggregation, while a PAc‐deficient mutant and two clinical isolates with no PAc expression did not. When platelets were pretreated with higher amounts of anti‐PAc serum, the platelet aggregation rate was reduced in a dose‐dependent manner, indicating that PAc binds directly to platelets.Conclusion:  S. mutans PAc is involved in human platelet aggregation and may be one of the virulence factors in the pathogenesis of infective endocarditis.
Analysis of Streptococcus mutans biofilm proteins recognized by salivary immunoglobulin A
Authors: Sanui T. , Gregory R. L. 
Published: August 2009

Introduction:  The purpose of this study was to examine the Streptococcus mutans biofilm cellular proteins recognized by immunoglobulin A (IgA) in saliva from various caries‐defined populations.Methods:  Biofilm and planktonic S. mutans UA159 cells were prepared. The proteins were extracted, separated by two‐dimensional gel electrophoresis, transferred to blotting membranes, and probed for IgA using individual saliva samples from three groups of subjects; those who developed 0 caries (no active caries), 5–9 caries (medium), or more than 10 caries (severe) over a 12‐month interval.Results:  Several proteins were recognized by salivary IgA in all groups of saliva but spot distribution and intensity varied greatly between the groups, and some proteins were recognized more strongly in biofilm cells than in planktonic culture, and vice versa. Furthermore, 15 proteins were only recognized by saliva from the ‘no active caries’ group, and four proteins were recognized by saliva samples from subjects in all three groups. Specifically, antigen I/II was recognized less in biofilm cells by caries‐free saliva compared with planktonic cells. However, salivary IgA antibody to antigen I/II was absent in blots using saliva from the ‘medium caries’ and ‘severe caries’ groups.Conclusion:  The bacterial molecules recognized by caries‐free saliva are significant factors for S. mutans caries formation, and their inhibition could be a therapeutic target. In addition, saliva of caries‐free subjects includes significant IgA antibody against antigen I/II of S. mutans, indicating a protective mechanism. However, microorganisms may protect themselves from host immune attack by forming biofilms and decreasing expression of antigen I/II.
Porphyromonas gingivalis mutant defective in a putative extracytoplasmic function sigma factor shows a mutator phenotype
Authors: Kikuchi Y. , Ohara N. , Ueda O. , Hirai K. , Shibata Y. , Nakayama K. , Fujimura S. 
Published: August 2009

Introduction:  Porphyromonas gingivalis is implicated as a major pathogen in the development and progression of chronic periodontitis. P. gingivalis must possess the ability to tolerate stress signals outside the cytoplasmic membrane by transcriptional activation of genes encoding proteins involved in defense or repair processes. Some bacteria utilize a distinct subfamily of sigma factors to regulate extracytoplasmic function (hence termed the ECF subfamily).Methods:  To elucidate their role in P. gingivalis, a chromosomal mutant carrying a disruption of an ECF sigma factor PG1318‐encoding gene was constructed. Hemagglutination and proteolytic activities were measured in the PG1318‐defective mutant. Reverse transcription‐polymerase chain reaction (RT‐PCR) analysis and southern blot analysis were used to assess transcription of kgp in the PG1318‐defective mutant. Frequency of spontaneous mutation that conferred resistance to l‐trifluoromethionine was measured in the PG1318‐defective mutant.Results:  The PG1318‐defective mutant formed non‐pigmented colonies on blood agar plates at a relatively high frequency. Arginine‐specific and lysine‐specific proteinase activities of the non‐pigmented variants were remarkably decreased compared with those of the parent strain and the pigmented variants. RT‐PCR analysis showed that kgp was not transcribed in some non‐pigmented variants and southern blot analysis revealed that there was a deletion in their kgp region. Frequency of mutation conferring resistance to l‐trifluoromethionine was significantly higher in the PG1318‐defective mutant than in the wild‐type.Conclusion:  These results suggest that PG1318 plays a role in the regulation of mutation frequency in the bacterium.
Detection of serotype k Streptococcus mutans in Thai subjects
Authors: Lapirattanakul J. , Nakano K. , Nomura R. , Nemoto H , Kojima A , Senawongse P. , Srisatjaluk R. , Ooshima T. 
Published: August 2009

Introduction:  Streptococcus mutans, known to be a pathogen of dental caries as well as bacteremia and infective endocarditis, is classified into four serotypes, c, e, f and k, based on the structures of serotype‐specific polysaccharides. Serotype k was recently designated using blood isolates from Japanese subjects and such strains are considered to be virulent in the bloodstream. The purpose of the present study was to analyse the serotype distribution of strains isolated from Thai subjects and determine whether serotype k strains were present.Methods:  A total of 250 S. mutans strains were isolated from 50 Thai subjects, and serotypes of all strains were determined. Then, molecular and biological analyses were carried out for serotype k strains.Results:  Immunodiffusion and polymerase chain reaction analyses showed that serotype c was the most prevalent (70%), followed by serotypes e (22.8%), f (4.4%) and k (2.8%), which indicated that serotype k S. mutans strains occurred in Thai individuals at a similar rate to that previously reported for Japanese and Finnish populations. Molecular analyses of the seven serotype k strains showed extremely low expression of rgpE, which is related to glucose side‐chain formation in serotype‐specific rhamnose‐glucose polymers, similar to previous reports for those other populations. In addition, analysis of the biological properties of the seven serotype k strains demonstrated low levels of sucrose‐dependent adhesion, cellular hydrophobicity, dextran‐binding activity and phagocytosis susceptibility by human polymorphonuclear leukocytes, which are characteristics similar to those of serotype k strains previously isolated in Japan.Conclusion:  Our results indicate the possibility of a worldwide prevalence of serotype k strains with properties in common with those of previously reported strains.
Human cytomegalovirus in peripheral giant cell granuloma
Authors: Saygun I. , Şahin S. , Muşabak U. , Enhoş Ş. , Kubar A. , Günhan Ö. , Slots J. 
Published: August 2009

Background:  The peripheral giant cell granuloma is a relatively common non‐neoplastic inflammatory lesion of gingiva, but the etiopathogeny remains unknown. This study aimed to evaluate the importance of human cytomegalovirus and Epstein–Barr virus in a peripheral giant cell granuloma of a 47‐year‐old female.Methods:  The lesion was studied clinically, histopathologically, immunologically and virologically using established procedures.Results:  The gingival growth was located at the mesial surface of the maxillary left canine having a vital pulp. The mass was 12 × 21 mm in size and exhibited a smooth surface with no evidence of fluctuation on palpation. An excisional biopsy revealed giant cells in a fibrohistiocytic stroma with areas of haemorrhage. Serum protein levels and lymphocyte subsets were within normal limits, except CD3+ and CD4+ cells were below normal ranges. Polymorphonuclear leukocytes expressed p150,95 (CD11c/CD18) and CXCR‐2 receptors within normal ranges, but the CXCR1 receptor showed decreased density, and CD15 were below normal range. A virological sample of the tooth surface adjacent to the gingival swelling yielded 7.6 × 103 copy‐counts of cytomegalovirus and 4.3 × 103 copy‐counts of Epstein–Barr virus.Conclusions:  The clinical and histological findings were consistent with the diagnosis of peripheral giant cell granuloma. Cytomegalovirus has the potential to induce multinucleated giant cells, and the possibility that the virus contribute to the development of peripheral giant cell granuloma merits further study.