bluuebunny/crossref_metadata_2025 huggingface dataset:
Allostery and cooperativity revisited
Authors: Cui Qiang , Karplus Martin
Published: June 2008

Although phenomenlogical models that account for cooperativity in allosteric systems date back to the early and mid‐60's (e.g., the KNF and MWC models), there is resurgent interest in the topic due to the recent experimental and computational studies that attempted to reveal, at an atomistic level, how allostery actually works. In this review, using systems for which atomistic simulations have been carried out in our groups as examples, we describe the current understanding of allostery, how the mechanisms go beyond the classical MWC/Pauling‐KNF descriptions, and point out that the “new view” of allostery, emphasizing “population shifts,” is, in fact, an “old view.” The presentation offers not only an up‐to‐date description of allostery from a theoretical/computational perspective, but also helps to resolve several outstanding issues concerning allostery.
Enzymatic and structural analysis of the I47A mutation contributing to the reduced susceptibility to HIV protease inhibitor lopinavir
Authors: Šašková Klára Grantz , Kožíšek Milan , Lepšík Martin , Brynda Jiří , Řezáčová Pavlína , Václavíková Jana , Kagan Ron M. , Machala Ladislav , Konvalinka Jan
Published: June 2008

Lopinavir (LPV) is a second‐generation HIV protease inhibitor (PI) designed to overcome resistance development in patients undergoing long‐term antiviral therapy. The mutation of isoleucine at position 47 of the HIV protease (PR) to alanine is associated with a high level of resistance to LPV. In this study, we show that recombinant PR containing a single I47A substitution has the inhibition constant (Ki) value for lopinavir by two orders of magnitude higher than for the wild‐type PR. The addition of the I47A substitution to the background of a multiply mutated PR species from an AIDS patient showed a three‐order‐of‐magnitude increase in Ki in vitro relative to the patient PR without the I47A mutation. The crystal structure of I47A PR in complex with LPV showed the loss of van der Waals interactions in the S2/S2′ subsites. This is caused by the loss of three side‐chain methyl groups due to the I47A substitution and by structural changes in the A47 main chain that lead to structural changes in the flap antiparallel β‐strand. Furthermore, we analyzed possible interaction of the I47A mutation with secondary mutations V32I and I54V. We show that both mutations in combination with I47A synergistically increase the relative resistance to LPV in vitro. The crystal structure of the I47A/I54V PR double mutant in complex with LPV shows that the I54V mutation leads to a compaction of the flap, and molecular modeling suggests that the introduction of the I54V mutation indirectly affects the strain of the bound inhibitor in the PR binding cleft.
Vessel features of threeCaraganaspecies in their natural habitats in the inner Mongolia Plateau of China
Authors: Li Jing , Gao Yubao , Wu Jianbo , Guo Hongyu
Published: June 2008

We studied the vessel features of ten populations of threeCaraganaspecies (C. microphyllaLam,C. davazamciiSancz,C. korshinskiiKom.), which form a geographical cline in the inner Mongolia Plateau of China.

All sampled shrubs had common vessel features of xeric plants, such as coexistence of wide and narrow vessels in one xylem, high vessel density, short element length, distinct helical thickenings, which were all associated with strong drought resistance. The quantitative vessel features changed gradually along the geographical gradient of the threeCaraganaspecies. Mean vessel diameter, D100, generally decreased from the east to the west. However, D95(the mean diameter of vessels responsible for 95% of the total stem conductance) changed in an opposite direction to D100, which might be attributed to different proportions of wide and narrow vessels of the ten populations. The more xeric the habitat was, the smaller the proportion of wide vessels (which contributed mainly to water conductance). There was also a tradeoff between efficiency and safety in water transport. The intervessel pit size, density of vessel elements, intervessel pits and helical thickenings increased from the east to the west with the increase of environmental aridity. The trend of vessel element length and wall thickness was similar to that of D100, i.e. they decreased from the east to the west. All these gradually changing features confirmed the geographical transition among the threeCaraganaspecies, and indicated an order of drought resistance asC. korshinskii>C. davazamcii>C. microphylla.
Silene kucukodukii sp. nov. (Caryophyllaceae) from south Anatolia, Turkey
Authors: Bağcı Yavuz , Uysal Tuna , Ertuğrul Kuddisi , Demirelma Hakkı
Published: June 2008

Silene kucukodukii Y. Bağcı & Uysal sp. nov. from the Hadim, (C4 Konya‐Turkey) is described and illustrated. It is closely related to S. sipylea O. Schwarz from which it differs morphologically mainly by the indumentum, leaf and floral features. Diagnostic morphological characters are discussed and a key of related Silene L. species in Turkey is given. The geographical distribution of the new species and other related species is mapped. Notes are also presented on its ecology, biogeography and conservation status. A chromosome count on Silene kucukodukii has been carried out and the chromosome number is 2n=24.
Cinnamomumchampokianum sp. Nov. (Lauraceae) from Assam, northeastern India
Authors: Baruah Akhil , Nath Subhan C.
Published: June 2008

Cinnamomum champokianum Baruah & S. C. Nath. is illustrated and described as a new species, with a note on its leaf, panicle and stem bark essential oils, reported earlier as a variant of Cinnamomum bejolghota (Buch.–Ham.) Sweet.
A morphometric analysis of species boundaries in the Bonatea cassidea complex
Authors: Ponsie Mariaan E. , Johnson Steven D. , Edwards Trevor J.
Published: June 2008

Taxa with large geographical ranges often exhibit clinal variation. Detailed morphometric analysis may be required to establish species boundaries in such taxa. The extensive morphological variation within the Bonateacassidea complex (comprising the closely related taxa Bonatea cassidea Sond. Bonatea saundersiae (Harv.) T. Durand & Schinz and Bonatea saundersioides (Kraenzl. & Schltr.) Cortesi) was analysed by means of multivariate PCA‐based analyses of herbarium material and box and whisker plots of key characters. Additional data on clinal variation was obtained from seven populations of B. cassidea spanning its distribution range. The taxonomic status of B. saundersiae is reconsidered in light of evidence that this taxon lacks clear diagnostic characters that would separate it from B. cassidea. The taxon is thus reduced to synonymy with B. cassidea. A synopsis of B. cassidea and its sister taxon B. saundersioides is presented.
Alliumertugrulii sp. nov. (Alliaceae) from southern Turkey
Authors: Demirelma Hakkı , Uysal Tuna
Published: June 2008

Allium ertugrulii Demirelma & Uysal sp. nov. (Alliaceae) is illustrated and described from the central Taurus, Turkey. The new species is compared with the morphologically similar A. cassium Boiss.
Tracking the gaze of birds
Authors: Kjærsgaard Anders , Pertoldi Cino , Loeschcke Volker , Witzner Hansen Dan
Published: June 2008

Accurate measurements of what birds are looking at are valuable to most studies of vision and visually guided behaviour in avian species. Compared to human visual research, studies of gaze behaviour in birds are limited. A new laser‐based method that can be used to quantify several aspects of a given sequence of gaze shifts and fixations is presented. Using near infrared light to estimate gaze direction is a relatively simple and cheap method to study visually guided behaviour. It has the potential to contribute significantly to the ornithological research by allowing the quantification of several behavioural traits of birds. Other methods are discussed and compared to the use of infrared light, and possible fields of application are suggested.
Daily energy expenditure of singing great reed warblers Acrocephalus arundinaceus
Authors: Hasselquist Dennis , Bensch Staffan
Published: June 2008

According to honest signalling theory, signals must be costly to produce to retain information about the signaller's quality. The song produced by male birds during breeding is a vocal “ornament” used for intra‐ and inter‐sexual purposes. The energetic cost of this vocal signal remains a contentious issue. We used the doubly labelled water method to measure field metabolic rate by estimating CO2 production and then convert this to daily energy expenditure (DEE) in great reed warbler males singing under natural conditions (10 at low to moderate intensity and 7 at very high intensity from dawn to dusk). There was a significant positive relationship between singing intensity and DEE. From this relationship we extrapolated the average DEE for intensely singing males (i.e., males producing song sounds 50% of the time and hence sitting at their elevated song post in the top of a reed stem more or less continuously throughout the ∼20 h of daylight) to 3.3×BMR (basal metabolic rate) and for non‐singing males to 2.2×BMR. The mean DEE measured for the seven males singing with very high intensity was 3.1×BMR. The maximum measured DEE for a single male was 3.9×BMR, i.e. close to the maximum sustainable DEE (4×BMR), and the minimum DEE was 2.1×BMR for a male singing at very low intensity. These results imply that producing intensive advertising song in birds may incur a substantial cost in terms of increased energy expenditure.
Snake activity affects seasonal variation in nest predation risk for birds
Authors: Sperry Jinelle H. , Peak Rebecca G. , Cimprich David A. , Weatherhead Patrick J.
Published: June 2008

Variation in predator behavior has been proposed, but not tested, as a mechanism producing seasonal declines in avian nest success. We test this hypothesis by documenting seasonal activity of Texas ratsnakes Elaphe obsoleta and nest failure of endangered black‐capped vireos Vireo atricapilla and golden‐cheeked warblers Dendroica chrysoparia on which the snakes prey. Nest survival analysis was based on 880 vireo and 228 warbler nests and 3,060 snake locations from 62 radio‐tracked snakes. Although nest success varied with snake activity for both birds, specific patterns differed substantially. Vireo daily nest survival was negatively correlated with snake activity over the three‐year study, despite substantial variation among years in weather, and the fact that these birds are almost certainly a minor prey species of the ratsnakes. Warblers exhibited less clear‐cut seasonal variation in nest success, and the association between nest success and snake activity was less pronounced than for vireos. Increased activity at warmer temperatures explained some of the seasonal change in snake movements, although mating may have accounted for a mid‐season peak in activity. These results indicate that variation in predator behavior can be associated with and potentially cause seasonal changes in nest success, but also that these relationships are species specific even within the same community and may depend on aspects of the nesting ecology of the prey such as nest site selection.
NPR1 and EDS11 contribute to host resistance against Fusarium culmorum in Arabidopsis buds and flowers
Authors: CUZICK ALAYNE , LEE SARAH , GEZAN SALVADOR , HAMMOND‐KOSACK KIM E.
Published: June 2008

The cereal ear blight fungal pathogen Fusarium culmorum can infect Arabidopsis floral tissue, causing disease symptoms and mycotoxin production. Here we assessed the effect of seven mutants and one transgenic overexpression line, residing in either the salicylic acid (SA), jasmonic acid (JA) or ethylene (ET) defence signalling pathways, on the outcome of the Fusarium–Arabidopsis floral interaction. The bacterial susceptiblity mutant eds11 was also assessed. Flowering plants were spray inoculated with F. culmorum conidia to determine the host responses to initial infection and subsequent colonization. Enhanced susceptibility and higher concentrations of deoxynivalenol mycotoxin were observed in buds and flowers of the npr1 and eds11 mutants than in the wild‐type Col‐0 plants. An effect of the other two defence signalling pathways on disease was either absent (ET/JA combined), absent/minimal (ET) or inconclusive (JA). Overall, this study highlights a role for NPR1 and EDS11 in basal defence against F. culmorum in some floral organs. This is the first time that any of these well‐characterized defence signalling mutations have been evaluated for a role in floral defence in any plant species.
Delineation of distinct tumour profiles in mantle cell lymphoma by detailed cytogenetic, interphase genetic and morphological analysis
Authors: Katzenberger Tiemo , Kienle Dirk , Stilgenbauer Stephan , Höller Sylvia , Schilling Carolin , Mäder Uwe , Puppe Bernhard , Petzoldt Celine , Sander Sandrine , Bullinger Lars , Stöcklein Heike , Kalla Jörg , Hartmann Elena , Adam Patrick , Ott M. Michaela , Müller‐Hermelink Hans‐Konrad , Rosenwald Andreas , Ott German
Published: June 2008

Mantle cell lymphoma (MCL) is an aggressive lymphoid tumour characterized by the translocation t(11;14)(q13;q32) and a poor clinical outcome (median survival: 3–4 years). Recent studies revealed that increased proliferation of the tumour cells and certain chromosomal aberrations, such as deletions of 17p13 and 9p21 represent major adverse biological markers in this disease, although the molecular targets of chromosomal imbalances in MCL have not been identified for the large majority of loci affected. To correlate histomorphological and proliferation features of MCL with genetic findings, we investigated 223 MCL by fluorescence in situ hybridization (FISH) (n = 157) and/or classical cytogenetic banding analysis (n = 129). FISH analysis turned out to be distinctly more sensitive in the delineation of aberrations. Complex karyotypic alterations were associated with higher proliferation indices and inferior prognosis. A comprehensive analysis of biological features including genetic alterations in MCL by hierarchical clustering resulted in the delineation of four tumour subgroups differing with respect to their genetic constitution and suggesting different transformation or progression pathways. Moreover, in one of the groups identified, a more indolent clinical behaviour was associated with few secondary aberrations and fewer known high‐risk chromosomal aberrations, which points to the importance of the quality of karyotypic evolution in MCL tumours.
Clinical features and outcome of pulmonary embolism in children
Authors: Biss Tina T. , Brandão Leonardo R. , Kahr Walter H. , Chan Anthony K. , Williams Suzan
Published: June 2008

Pulmonary embolism (PE) is rare in childhood but evidence suggests it is under‐recognised. Children diagnosed with PE at a large tertiary centre over an 8‐year period were retrospectively reviewed. Fifty‐six children with radiologically proven PE were identified, 31 males and 25 females, median age 12 years. Eighty‐four per cent had symptoms of PE. Risk factors for thromboembolism were present in 54 patients (96·4%); most commonly immobility (58·9%), central venous line (35·7%) and recent surgery (28·6%). Investigation revealed a thrombophilic abnormality in 14/40 patients (35%). Concurrent deep vein thrombosis was confirmed in 31 patients (55·4%), predominantly lower limb. D dimer was elevated at presentation in 26/30 patients (86·7%). Eight patients underwent systemic thrombolysis. An inferior vena cava filter was placed in five patients. Therapy was complicated by major haemorrhage in 12 patients (21·4%). The majority (82·1%) had complete or partial resolution of PE following a median of 3 months anticoagulation. Seven patients had a recurrent thromboembolic event and 12 patients died (mortality 21·4%); five due to thromboembolism (8·9%) and two due to haemorrhage. Risk factors for PE in children are distinct from adults and morbidity and mortality is significant. Multicentre prospective studies are required to determine optimal treatment and long‐term outcome of childhood PE.
Understanding and harnessing the graft‐versus‐leukaemia effect
Authors: Barrett A. John
Published: June 2008

The graft‐versus‐leukaemia (GVL) effect is a central component of the stem cell allograft’s ability to cure haematological malignancies. The GVL effect is mediated by donor‐derived natural killer cells and T lymphocytes, which have distinct mechanisms of recognizing and targeting the recipient’s malignant cells. After transplantation the cytokine milieu is favourable to the early establishment of a GVL effect, but the need to prevent graft‐versus‐host disease limits the full potential of this process. Clinical studies have identified some critical components of the transplant preparation, donor selection, stem cell source (peripheral blood versus bone marrow) and post‐transplant management that can be manipulated to optimize the GVL effect. However, further developments focusing on the selective depletion of unwanted alloreactivity with preservation of GVL effects, and the use of vaccines or the adoptive transfer of leukaemia‐specific lymphocytes, will be required to enhance the GVL effect to reliably eradicate more resistant leukaemias.
High expression of the cGMP‐specific phosphodiesterase, PDE9A, in sickle cell disease (SCD) and the effects of its inhibition in erythroid cells and SCD neutrophils
Authors: Almeida Camila Bononi , Traina Fabiola , Lanaro Carolina , Canalli Andreia A. , Saad Sara T. O. , Costa Fernando F. , Conran Nicola
Published: June 2008

Modulation of intracellular cyclic guanosine monophosphate (cGMP) may characterize a therapeutic target for sickle cell disease (SCD); cGMP‐dependent signalling may be important for erythroid foetal haemoglobin induction and exert anti‐inflammatory functions in leucocytes. As the inhibition of phosphodiesterases (PDEs), which regulate intracellular cGMP, can result in tissue‐specific elevation of cGMP, we studied the gene expressions of cGMP‐specific PDEs (−1A, −5A and −9A) in the reticulocytes and neutrophils of healthy controls, steady‐state SCD patients and SCD patients on hydroxycarbamide therapy (SCDHC). PDE9A gene expression was found in numerous cell types; however, high expression was found in neutrophils, reticulocytes, CD34+‐derived erythroid cells and K562 erythroleukaemic cells, indicating a high haematopoietic cell expression. PDE9A gene expression was, however, significantly higher in the reticulocytes and neutrophils of SCD individuals, compared to control cells; Western blotting confirmed the production of PDE9A protein in SCD neutrophils and K562 cells. Inhibition of PDE9A enzyme with the specific inhibitor, BAY73‐6691, significantly increased production of the γ‐globin gene (HBG) in K562 cells and reversed the increased adhesive properties of SCD neutrophils. Since elevation of haematopoietic intracellular cGMP may be beneficial in SCD, the relatively limited tissue distribution of PDE9A suggests that it could represent a novel drug target worthy of further study.
Thrombin generation testing in routine clinical practice: are we there yet?
Authors: Van Veen J. J. , Gatt A. , Makris M.
Published: June 2008

Thrombin is the central enzyme in the coagulation cascade. Estimation of an individual’s potential to generate thrombin may correlate more closely with a hyper‐ or hypo‐coagulable phenotype, compared to traditional coagulation tests. The possible correlation and recent technical advances in thrombin generation measurement has caused a significant interest in the method and the development of commercial assays. Several variations of the assay exist depending on the defect to be investigated. Fluorogenic thrombin generation assays have acceptable intra‐laboratory variation but a higher inter‐laboratory variation. Variation in preanalytical variables makes comparisons between studies difficult. Thrombin generation is highly variable between individuals and there are suggestions that this may allow individualized treatment based on global haemostatic response in patients with bleeding disorders or on anticoagulant therapy. In patients with thrombotic disorders it may be possible to identify those at higher risk of recurrent thrombosis. For both scenarios, however, data from large prospective studies are lacking or inconclusive and a good relationship between thrombin generation and phenotype remains to be established. Further standardization of the assay is needed before large multicentre studies can be conducted and until then thrombin generation in routine clinical practice is not yet a reality.
Multiplex ligation‐dependent probe amplification for detection of genomic alterations in chronic lymphocytic leukaemia
Authors: Coll‐Mulet Llorenç , Santidrián Antonio F. , Cosialls Ana M. , Iglesias‐Serret Daniel , De Frias Mercè , Grau Javier , Menoyo Anna , González‐Barca Eva , Pons Gabriel , Domingo Alicia , Gil Joan
Published: June 2008

Chronic lymphocytic leukaemia (CLL) is the commonest form of leukaemia in adults in Western countries. We performed multiplex ligation‐dependent probe amplification (MLPA) analysis in 50 CLL patients to identify multiple genomic CLL‐specific targets, including genes located at 13q14, 17p13 (TP53), 11q23 (ATM) and chromosome 12, and compared the results with those obtained with fluorescence in situ hybridization (FISH). There was a good correlation between MLPA and FISH results, as most alterations (89%) were detected by both techniques. Only three cases with a low percentage (<25%) of cells carrying the alterations were not detected by MLPA. On the other hand, as MLPA uses multiple probes it identified intragenic or small alterations undetected by FISH in three cases. MLPA also detected alterations in 8q24 (MYC) and 6q25–26. In summary, unlike interphase FISH, MLPA enabled the simultaneous analysis of many samples with automated data processing at a low cost. Therefore, the combination of robust multiplexing and high throughput makes MLPA a useful technique for the analysis of genomic alterations in CLL.
Disease staging with positron emission tomography or gallium scanning and use of rituximab predict outcome for patients with diffuse large B‐cell lymphoma treated with autologous stem cell transplantation
Authors: Alousi Amin M. , Saliba Rima M. , Okoroji Grace‐Julia , Macapinlac Homer A. , Hosing Chitra , Korbling Martin , Samuels Barry I. , Popat Uday , Kebriaei Partow , Anderlini Paolo , Qazilbash Muzaffar H. , De Lima Marcos , Giralt Sergio A. , Champlin Richard E. , Khouri Issa F.
Published: June 2008

Tumor status, as determined by positron emission tomography or gallium scanning (PET/G), may be an important predictor of outcome for patients with diffuse large B‐cell lymphoma (DLBCL) undergoing autologous stem cell transplantation (ASCT). ASCT conditioning regimens that include rituximab may reduce the rate of relapse. We evaluated the influence of rituximab on overall and progression‐free survival in patients with DLBCL based on PET/G status before ASCT. A retrospective review of all patients with chemosensitive DLBCL who underwent ASCT in the context of research protocols at our institution between 1995 and 2005 was performed. Our study included 174 patients. Disease status before ASCT, according to PET/G, was negative in 136 patients (78%), positive in 29 patients (17%), and unknown in nine patients (5%). PET/G status and rituximab use were the only factors predictive of progression‐free survival in multivariate analyses: the hazard ratios for relapse were 2·9 for PET/G‐positive versus ‐negative patients (P < 0·001) and 0·4 for rituximab versus no rituximab use (P = 0·001). We conclude that evidence of disease on PET/G scanning prior to transplantation is associated with an increased risk for relapse after ASCT. Transplantation regimens containing rituximab can reduce this risk, regardless of PET/G status.
Peanut‐specific B and T cell responses are correlated in peanut‐allergic but not in non‐allergic individuals
Authors: Turcanu V. , Winterbotham M. , Kelleher P. , Lack G.
Published: June 2008

Objective
We aim to find what is the relationship between B cell antibody responses and specific T cell help in the specific cases of allergy and tolerance to peanuts.

Background
B cell antibody responses to foreign proteins usually depend upon antigen‐specific T cell help. However, specific antibody levels can sometimes be maintained lifelong after infections or vaccination.

Methods
We measured peanut‐specific proliferation and antibody levels in peanut‐allergic and non‐allergic children using tritiated thymidine incorporation and UniCAP, respectively. We also investigated the corresponding tetanus toxoid specific responses in both groups.

Results
We found that tetanus‐specific IgG did not correlate with lymphocyte proliferation (Spearman rank correlation coefficient r′=0.08, P=0.74) nor with tetanus‐specific cytokine production (IFN‐γ: r′=0.198, P=0.285; TNF‐α: r′=0.274, P=0.146; IL‐4: r′=−0.007, P=0.96; P=0.221; IL‐13: r′=0.363, P=0.056). Conversely, in peanut‐allergic donors, peanut‐specific IgE (average 21 kU/L, median 2.27 kU/L, range 0.34‐100 kU/L) but not peanut‐specific IgG was positively correlated with proliferation (r′=0.751, P=0.003). In these donors, specific IgE was positively correlated with peanut‐specific Th2 cytokines production: r′=0.635, P=0.02 for IL‐4 and r′=0.641, P=0.025 for IL‐13 and negatively correlated with Th1 cytokines (r′=−0.71, P=0.007 for IFN‐γ and r′=−0.746, P=0.005 for TNF‐α, respectively). However, peanut‐specific IgE was not correlated with T cell proliferation or cytokine production in non‐allergic individuals. In conclusion, in allergic individuals, B and T cell responses to peanut antigens are correlated whereas normal immune responses B and T cell responses are uncoupled.

Conclusion
Our results support the view that B cell responses to allergens but not those to non‐allergenic proteins are correlated with specific T cell responses and therefore specific immunotherapy targeting of such T cells would inhibit allergen‐specific B cells.
Heterogeneity of commercial timothy grass pollen extracts
Authors: Focke M. , Marth K. , Flicker S. , Valenta R.
Published: June 2008

Background
The diagnosis and specific immunotherapy of allergy is currently performed with allergen extracts prepared from natural allergen sources.

Objective
To analyse commercial timothy grass pollen allergen extracts used for in vivo diagnosis regarding their qualitative and quantitative allergen composition and in vivo biological activity.

Methods
Antibodies specific for eight timothy grass pollen allergens (Phl p 1, Phl p 2, Phl p 4, Phl p 5, Phl p 6, Phl p 7, Phl p 12, Phl p 13) were used to detect these allergens in timothy grass pollen extracts from four manufacturers by immunoblotting. ELISA assays were developed and used to quantify the three major allergens (Phl p 1, Phl p 2, Phl p 5) in the extracts. The magnitude of skin responses to the four extracts was studied by skin prick testing in 10 grass pollen‐allergic patients.

Results
The allergen extracts showed broad variations in protein compositions and amounts (24.1–197.7 μg/mL extract). Several allergens could not be detected in certain extracts or appeared degraded. A considerable variability regarding the contents of major allergens was found (Phl p 1: 32–384 ng/mL; Phl p 2: 1128–6530 ng/mL, Phl p 5: 40–793 ng/mL). Heterogeneous skin test results were obtained with the extracts in grass pollen‐allergic patients.

Conclusions
Timothy grass pollen extracts from different manufacturers exhibit a considerable heterogeneity regarding the presence of individual allergens and hence yield varying in vivo test results. Problems related to the use of natural grass pollen allergen extracts may be circumvented by using defined recombinant grass pollen allergens.
Bakery flour dust exposure causes non‐allergic inflammation and enhances allergic airway inflammation in mice
Authors: Marraccini P. , Brass D. M. , Hollingsworth J. W. , Maruoka S. , Garantziotis S. , Schwartz D. A.
Published: June 2008

Background
Baker's asthma is one of the most commonly reported occupational lung diseases in countries where fresh bread is baked daily in large quantities, and is characterized by rhinitis, bronchial hyperresponsiveness, and reversible airflow obstruction. Epidemiological studies have identified pre‐existing atopy as an important risk factor for developing baker's asthma, yet the aetiology and pathogenesis of baker's asthma remain poorly understood.

Objective
We sought to develop a mouse model of baker's asthma that could be used to characterize the development and progression of baker's asthma.

Methods
We were unable to sensitize mice to bakery flour dust or flour dust extract. We assessed total inflammatory cells, cellular differential, total serum IgE and the pro‐inflammatory cytokine response to oropharyngeally instilled bakery flour dust or flour dust extract by itself or in the context of ovalbumin (OVA) sensitization and challenge.

Results
Both bakery flour dust and flour dust extract consistently elicited a neutrophilic inflammation in a Toll‐like receptor 4‐independent manner; suggesting that endotoxin is not playing a role in the inflammatory response to flour dust. Moreover, bakery flour dust and dust extract significantly enhance the inflammatory response in OVA‐sensitized and challenged mice.

Conclusions
Bakery flour dust and flour dust extract are strongly pro‐inflammatory and can cause non‐allergic airway inflammation and can enhance allergen‐mediated airway inflammation.
Localization and function of histamine H3receptor in the nasal mucosa
Authors: Suzuki S. , Takeuchi K. , Majima Y.
Published: June 2008

BackgroundHistamine is an important chemical mediator of allergic rhinitis (AR). Histamine H3receptors (H3R) are located on cholinergic and NANC neurons of the myenteric plexus, and activation of H3R regulates gastric acid secretion. However, little is known about the localization and function of H3R in the upper airway.

ObjectiveThe objective of this study was to examine the localization and possible function of H3R in the nasal mucosa.

MethodsWe extracted total RNA from the inferior turbinate mucosa of patients with AR. H3R mRNA and β‐actin mRNA were amplified by RT‐PCR. We used immunohistochemistry to examine localization of H3R protein in the inferior turbinate mucosa excised during clinically indicated surgery. We used alcian blue/periodic acid‐shiff staining to examine the effects of the H3R agonist (R)‐α‐methylhistamine and the H3R antagonist thioperamide on secretion from rat submucosal glands.

ResultsH3R protein was expressed around submucosal gland cells. Thioperamide induced degranulation in the submucosal gland in the nasal septum.

ConclusionThe present results suggest that H3R is localized mainly around submucosal glands, and that H3R plays an important role in the secretion of submucosal glands in the nose.
Clinical effects of immunotherapy with genetically modified recombinant birch pollen Bet v 1 derivatives
Authors: Purohit A. , Niederberger V. , Kronqvist M. , Horak F. , Grönneberg R. , Suck R. , Weber B. , Fiebig H. , Van Hage M. , Pauli G. , Valenta R. , Cromwell O.
Published: June 2008

Background
Birch pollen and pollen from related trees of the Fagales order are a major cause of allergic rhinitis, conjunctivitis, and asthma through the spring season in northern and central Europe.

Objective
To investigate the clinical effects of injection immunotherapy with genetically modified derivatives of major birch pollen allergen Bet v 1 on pollen‐induced allergic symptoms.

Methods
A three‐arm double‐blind placebo‐controlled immunotherapy study was conducted with one pre‐seasonal course of treatment using two derivatives of Bet v 1, namely a recombinant Bet v 1 trimer and an equimolar mixture of two recombinant Bet v 1 fragments together representing the whole protein sequence. Analysis of local and systemic adverse events was performed for 124 patients who had received at least one dose of medication. Clinical efficacy was monitored by symptom medication scores and interval scoring in the per protocol‐treated population (n=84). In addition, skin and nasal provocation responses and allergen‐specific antibodies were assessed.

Results
There were trends towards improvement in the subjects' well‐being and clinical symptoms (nasal scores), although comparisons with a placebo group did not show statistical significance in the main end‐point, the combined symptom medication score. Reductions in skin and nasal sensitivity were observed for some subjects with a trend for the Bet v 1 trimer to be more effective than the fragments. Treatment induced strong IgG1 and IgG4 allergen‐specific antibody responses. Local injection‐site reactions were most frequent in the trimer group affecting 59.5% of patients as opposed to 37.8% and 30.6% in the fragment and placebo groups, respectively. Systemic reactions were elicited more frequently by fragments. A large proportion of adverse side‐effects appeared hours following injections, and might be attributable to concurrent exposure to related pollens.

Conclusion
Single courses of injection immunotherapy with Bet v 1 allergen derivatives showed trends towards improved well‐being and reduced reactivity to specific allergen provocation, but did not yield significant improvement in the combined symptom medication score in this study.
Type III IFN‐λ mRNA expression in sputum of adult and school‐aged asthmatics
Authors: Bullens Dominique M. A. , Decraene A. , Dilissen E. , Meyts I. , De Boeck K. , Dupont L. J. , Ceuppens J. L.
Published: June 2008

Background
The increased susceptibility of asthmatics to rhinovirus infection has recently been related to deficient IFN‐λ1 (IL‐29) and IFN‐λ2/3 (IL‐28) production by bronchial epithelial cells and macrophages.

Objectives
Here, we studied IFN‐λ mRNA expression in the airways of stable asthmatics in comparison with healthy subjects and in relation to asthma symptoms, non‐invasive parameters of airway inflammation and lung function parameters.

Methods
Airway cells were obtained by sputum induction, in 14 healthy and 35 asthmatic adults and 12 asthmatic school‐aged children. IFN‐λ was studied at the mRNA level by quantitative RT‐PCR.

Results
Asthmatic adults have increased sputum IL‐28 mRNA but similar IL‐29 mRNA expression in comparison with healthy subjects. In asthmatics, both sputum IL‐28 and IL‐29 mRNA expression correlate with the sputum CD3γ mRNA expression (reflecting infiltrated T cells). IL‐28 (but not IL‐29) mRNA levels correlate with the relative and absolute number of eosinophils present in the sputum sample. Sputum IL‐29 mRNA (but not IL‐28) correlates negatively with asthma symptoms in steroid‐naïve patients and is significantly higher in steroid‐treated than in steroid‐naïve patients. Finally, both IL‐28 and IL‐29 mRNA levels are higher in asthmatic children than in asthmatic adults.

Conclusion
Our results show that asthmatic subjects have substantial type III IFN‐λ mRNA levels in the airways. Our data furthermore suggest that IL‐29 could have an immunoprotective role in the lower airways.
Evaluating large‐scale effects of Bacillus thuringiensis var. israelensis on non‐biting midges (Chironomidae) in a eutrophic urban lake
Authors: VAUGHAN I. P. , NEWBERRY C. , HALL D. J. , LIGGETT J. S. , ORMEROD S. J.
Published: June 2008

1. There is continued interest in controlling non‐biting midges (chironomids) in some freshwaters because of the potential nuisance caused by emergent adults. One option is to apply Bacillus thuringiensis var. israelensis (Bti), primarily used against mosquitoes and blackflies, to control benthic chironomid larvae. Chironomids are also at risk of collateral effects where Bti is used on other targets, and such instances may increase if climate change alters the incidence of dipteran‐borne diseases. However, most research on Bti effects on chironomids is available from mesocosms or ponds and might not scale‐up to larger waterbodies.

2. We present results on the effects of Bti on larval chironomids from eight experimental treatments, over 3 years, on a newly created eutrophic, urban lake of 200 ha, Cardiff Bay.

3. The first two experimental years provided limited evidence of Bti effects, with chironomid densities reduced by up to 14%. Increased scale of application and altered experimental design in the third year revealed reductions in chironomid larval densities of around 35% following Bti treatment, with suppression lasting several months.

4. These large‐scale Bti experiments – among the largest ever undertaken on chironomids – complement previous smaller‐scale experiments in illustrating how field conditions and application methods influence Bti effects on chironomid densities. Specifically, the work reveals how near‐neutral buoyancy formulations of Bti can reduce chironomid numbers in large lakes exceeding 3 m depth, but only where treatment methods avoid over‐dispersion. We advocate further evaluation to assess whether chironomids can be suppressed over longer periods using whole‐lake application without long‐term ecological implications or excessive cost. We also suggest further consideration be given to non‐buoyant Bti formulations for use in deeper lakes.
Increased proportion of CD56bright natural killer cells in active and inactive systemic lupus erythematosus
Authors: Schepis Danika , Gunnarsson Iva , Eloranta Maija‐Leena , Lampa Jon , Jacobson Stefan H. , Kärre Klas , Berg Louise
Published: June 2008

Natural killer (NK) cells belong to the innate immune system but can also affect adaptive immune reactions. This immune regulatory function is often ascribed to the CD56bright subpopulation of NK cells that is prevalent in secondary lymphoid tissues and has potent cytokine‐producing ability. The NK cells have been described as affecting autoimmune disease and stimulating B‐cell production of antibodies, but their role in systemic lupus erythematosus (SLE) pathology has not been extensively studied. We have studied NK cells in SLE, a B‐cell‐driven systemic autoimmune disease, and phenotypically characterized peripheral blood NK cells in comparison to NK cells from patients with immunoglobulin A nephritis, rheumatoid arthritis and healthy individuals. We have found an increased proportion of CD56bright NK cells in SLE, regardless of disease activity. We detected a somewhat increased expression of the activating receptor NKp46/CD335 on NK cells from SLE patients, although neither the percentage of NK cells of all lymphocytes nor the expression of other NK receptors analysed (LIR‐1/CD85j, CD94, NKG2C/CD159c, NKG2D/CD314, NKp30/CD337, NKp44/CD336, CD69) differed between patient groups. We show that type I interferon, a proinflammatory cytokine known to be abundant in SLE, can cause increases of CD56bright NK cells in vitro. We confirmed that serum levels of interferon‐α were increased in active, but not in inactive, disease in the SLE patient group. In conclusion, we found an increased proportion of CD56bright NK cells in the blood of SLE patients, although it remains to be examined whether and how this relates to the disease process.
Impact of an exotic earthworm on seed dispersal of an indigenous US weed
Authors: Regnier E. , Harrison S. K. , Liu J. , Schmoll J. T. , Edwards C. A. , Arancon N. , Holloman C.
Published: June 2008

Ambrosia trifida L. (giant ragweed), an aggressive weed of US grain crops and indigenous to North America, colonizes no‐tillage crop fields and undisturbed soils despite its large seed size and susceptibility to seed predation. Secondary seed dispersal is critical to seed survival and seedling establishment, yet mechanisms of secondary dispersal are poorly understood for such large‐seeded weedy species.

Field experiments were conducted to determine how seed foraging by the European exotic burrowing earthworm Lumbricus terrestris L., affected A. trifida seed burial and seedling recruitment, and to determine seed selectivity by L. terrestris.

Earthworms collected and buried over 90% of A. trifida seeds placed on the soil surface at a rate eightfold faster than abiotic seed burial. There was a sixfold higher concentration of seeds in burrows than in surrounding soil and a mean of 127 A. trifida seeds per burrow after a single season of A. trifida seed dispersal.

Earthworms buried A. trifida seeds from 0·5 to 22 cm deep and reduced recruitment by 37% compared to seeds buried abiotically and protected from predators, due to burial of some seeds below emergence depth limits. However, seedling biomass was increased by 30%.

Earthworms foraged selectively among seeds of 11 large‐seeded species and collected more seeds of A. trifida than of other species. The earthworms buried small (8·5 mm) A. trifida seeds more deeply and reduced their emergence more than large (11·5 mm) A. trifida seeds.

Synthesis and applications. The novel interaction of L. terrestris and A. trifida increases seed bank formation of A. trifida. Burrows of L. terrestris provide safe sites for seeds of A. trifida that may increase seedling establishment in environments with a high risk of seed predation. Control measures to prevent reproduction by A. trifida should be increased where L. terrestris is present due to the earthworms’ ability to bury and protect weed seeds. Selective seed caching by this widely distributed earthworm species may change plant community composition in agricultural and natural areas in North America and influence the evolution of seed traits. Land managers should consider the effects of L. terrestris on seedling regeneration of native and exotic plant species in areas undergoing colonization by L. terrestris.
Cross‐age peer tutors in asynchronous discussion groups: studying the impact of tutors labelling their interventions
Authors: De Smet M. , Van Keer H. , Valcke M.
Published: June 2008

Cross‐age tutors were randomly assigned to one of the three tutor training conditions distinguished for the current study: (1) the labelling experimental condition, characterized by requirements to label their tutor interventions, based on the e‐moderating model of Salmon; (2) the non‐labelling experimental condition, focusing on tutor's acting upon the role of an e‐moderator without preliminary requirements with regard to labelling the phase of e‐moderating in their messages; and (3) a control condition, typified by all‐round information on online facilitation. The results indicated that tutors are not really capable in labelling their interventions accurately. Nevertheless, labelling did foster enhanced e‐moderating activities. Compared to tutors in the control condition, tutors in the experimental conditions performed at a higher level, implying that they adopted more balanced tutor support. Labelling did not result in a differential impact on self‐efficacy and perceived collective efficacy.
A multidimensional approach to determinants of computer use in primary education: teacher and school characteristics
Authors: Tondeur J. , Valcke M. , Van Braak J.
Published: June 2008

The central aim of this study was to test a model that integrates determinants of educational computer use. In particular, the article examines teacher and school characteristics that are associated with different types of computer use by primary school teachers. A survey was set up, involving 527 teachers from 68 primary schools in Flanders. A separate questionnaire was administered to information and communication technology (ICT) coordinators from the same schools to gather additional information about cultural and contextual school characteristics. The combined impact of both teacher and school characteristics was explored through a multilevel analysis. Besides the importance of school characteristics, the results reveal differential effects of specific characteristics on specific types of computer use. Cultural school characteristics for instance, such as the schools’ openness to change and the availability of an ICT school policy plan, are positively related to the use of computers as a learning tool and to the adoption of ICT in view of basic computer skills. In contrast, no cultural school characteristic seem to be associated with the use of computers as an information tool. In a comparable way, teacher characteristics are associated with specific types of computer use, e.g. the variable gender. In general, male teachers report integrating computers more often. In this study, it appears that gender differences only exist in relation to the adoption of computers as an information tool. The results demonstrate that a multidimensional approach provides more insight into the characteristics affecting computer use.
Hypothalamic Control of the Pituitary‐Gonadal Axis in Higher Primates: Key Advances over the Last Two Decades
Authors: Plant T. M.
Published: June 2008

This review provides a brief historical background to the foundation of primate reproductive neuroendocrinology that was laid by Ernst Knobil during the late 1960s and early 1970s. This is followed by a discussion of studies conducted over the last two decades that I view as having contributed to the current understanding of the field of primate reproductive neuroendocrinology. The review concludes with a short summary of key questions that remain to be addressed.
The Neuroendocrinology of Stress: A Never Ending Story
Authors: Lightman S. L.
Published: June 2008

Evolutionary success depends on our ability to adapt to changing circumstances. The neuroendocrine response to stress is an excellent example of a plastic system that responds to threats to homeostasis and alters its output to meet current and expected future demands. At the level of the hypothalamus, the corticotroph secretagogues corticotrophin‐releasing hormone (CRH) and arginine vasopressin (AVP) respond rapidly to an acute stressor but, following chronic stress, they adapt with a reduction of CRH but a major increase in AVP. The release of CRH and AVP activates pro‐opiomelanocortin in anterior pituitary corticotroph cells and the release of adrenocorticotrophic hormone into peripheral blood from where it targets receptors in the adrenal cortex to release glucocorticoid hormones. These hormones (i.e. corticosterone in the rat and cortisol in man) are released in a pulsatile ultradian pattern which defines the normal circadian rhythm. The frequency of the pulses is increased under states of chronic stress, and in rats with genetically determined hyper‐responsiveness of the hypothalamic‐pituitary‐adrenal axis. Interestingly, neonatal influences can also programme alterations in ultradian rhythmicity, implicating epigenetic factors in its regulation. At the level of tissue receptors, the alteration in pattern of glucocorticoid ultradian rhythm has differential effects on mineralocorticoid receptor and glucocorticoid receptor (GR) binding to DNA and offers a mechanism for tissue specific responses to altered glucocorticoid dynamics. The effects of neonatal experience are not only seen at the level of CRH and GR regulation, but also are evident in behavioural responses to stress and in the responsiveness of brain stem serotonergic pathways, as measured by tryptophan hydroxylase mRNA in the brain stem.