bluuebunny/crossref_metadata_2025 huggingface dataset:
Involvement of RTE1 in conformational changes promoting ETR1 ethylene receptor signaling in Arabidopsis
Authors: Resnick Josephine S. , Rivarola Maximo , Chang Caren
Published: July 2008

Ethylene is an important regulator of plant growth, development and responses to environmental stresses. Arabidopsis perceives ethylene through five homologous receptors that negatively regulate ethylene responses. RTE1, a novel gene conserved in plants, animals and some protists, was recently identified as a positive regulator of the ETR1 ethylene receptor. Here, we genetically analyze the dependence of ETR1 on RTE1 in order to obtain further insight into RTE1 function. The function of RTE1 was found to be independent and distinct from that of RAN1, which encodes a copper transporter required for ethylene receptor function. We tested the ability of an rte1 loss‐of‐function mutation to suppress 11 etr1 ethylene‐binding domain mis‐sense mutations, all of which result in dominant ethylene insensitivity due to constitutive signaling. This suppression test uncovered two classes of etr1 mutations –RTE1‐dependent and RTE1‐independent. The nature of these mutations suggests that the ethylene‐binding domain is a possible target of RTE1 action. Based on these findings, we propose that RTE1 promotes ETR1 signaling through a conformational effect on the ethylene‐binding domain.
GLK transcription factors regulate chloroplast development in a cell‐autonomous manner
Authors: Waters Mark T. , Moylan Elizabeth C. , Langdale Jane A.
Published: July 2008

In a number of land plants, Golden2‐like (GLK) genes encode a pair of partially redundant nuclear transcription factors that are required for the expression of nuclear photosynthetic genes and for chloroplast development. As chloroplast biogenesis depends on close co‐operation between the nuclear and plastid compartments, GLK gene function must be dependent on tight intracellular control. However, the extent to which GLK‐mediated chloroplast development depends on intercellular communication is not known. Here we used sector analysis to show that GLK proteins operate cell‐autonomously in leaf mesophyll cells. To establish whether GLK proteins are able to influence adjacent cell layers, we used tissue‐specific promoters to restrict GLK gene expression to the epidermis and to the phloem. GLK genes driven by the Arabidopsis epidermal FIDDLEHEAD (FDH) and MERISTEM LAYER1 (AtML1) promoters failed to rescue the pale‐green Atglk1 Atglk2 mutant phenotype, confirming the suggestion that GLK proteins can only influence chloroplast development intracellularly. An exception to this rule was seen in lines in which GLK genes were expressed in the phloem. However, we believe that the partial complementation of the mutant phenotype that was observed resulted from phloem unloading, as opposed to inherent properties of GLK proteins. We conclude that GLK proteins act in a cell‐autonomous manner to coordinate and maintain the photosynthetic apparatus within individual cells. Significantly, this suggests that GLK proteins provide a means to fine‐tune photosynthesis according to the differential requirements of cells within the leaf.
Stress generation in the tension wood of poplar is based on the lateral swelling power of the G‐layer
Authors: Goswami Luna , Dunlop John W.C. , Jungnikl Karin , Eder Michaela , Gierlinger Notburga , Coutand Catherine , Jeronimidis George , Fratzl Peter , Burgert Ingo
Published: July 2008

The mechanism of active stress generation in tension wood is still not fully understood. To characterize the functional interdependency between the G‐layer and the secondary cell wall, nanostructural characterization and mechanical tests were performed on native tension wood tissues of poplar (Populus nigra × Populus deltoids) and on tissues in which the G‐layer was removed by an enzymatic treatment. In addition to the well‐known axial orientation of the cellulose fibrils in the G‐layer, it was shown that the microfibril angle of the S2‐layer was very large (about 36°). The removal of the G‐layer resulted in an axial extension and a tangential contraction of the tissues. The tensile stress–strain curves of native tension wood slices showed a jagged appearance after yield that could not be seen in the enzyme‐treated samples. The behaviour of the native tissue was modelled by assuming that cells deform elastically up to a critical strain at which the G‐layer slips, causing a drop in stress. The results suggest that tensile stresses in poplar are generated in the living plant by a lateral swelling of the G‐layer which forces the surrounding secondary cell wall to contract in the axial direction.
Identification of a functionally essential amino acid for Arabidopsis cyclic nucleotide gated ion channels using the chimeric AtCNGC11/12 gene
Authors: Baxter Joyce , Moeder Wolfgang , Urquhart William , Shahinas Dea , Chin Kimberley , Christendat Dinesh , Kang Hong‐Gu , Angelova Magdalena , Kato Naohiro , Yoshioka Keiko
Published: July 2008

We used the chimeric Arabidopsis cyclic nucleotide‐gated ion channel AtCNGC11/12 to conduct a structure–function study of plant cyclic nucleotide‐gated ion channels (CNGCs). AtCNGC11/12 induces multiple pathogen resistance responses in the Arabidopsis mutant constitutive expresser of PR genes 22 (cpr22). A genetic screen for mutants that suppress cpr22‐conferred phenotypes identified an intragenic mutant, #73, which has a glutamate to lysine substitution (E519K) at the beginning of the eighth β‐sheet of the cyclic nucleotide‐binding domain in AtCNGC11/12. The #73 mutant is morphologically identical to wild‐type plants and has lost cpr22‐related phenotypes including spontaneous cell death and enhanced pathogen resistance. Heterologous expression analysis using a K+‐uptake‐deficient yeast mutant revealed that this Glu519 is important for AtCNGC11/12 channel function, proving that the occurrence of cpr22 phenotypes requires active channel function of AtCNGC11/12. Additionally, Glu519 was also found to be important for the function of the wild‐type channel AtCNGC12. Computational structural modeling and in vitro cAMP‐binding assays suggest that Glu519 is a key residue for the structural stability of AtCNGCs and contributes to the interaction of the cyclic nucleotide‐binding domain and the C‐linker domain, rather than the binding of cAMP. Furthermore, a mutation in the α‐subunit of the human cone receptor CNGA3 that causes total color blindness aligned well to the position of Glu519 in AtCNGC11/12. This suggests that AtCNGC11/12 suppressors could be a useful tool for discovering important residues not only for plant CNGCs but also for CNGCs in general.
Efficient virus‐induced gene silencing in Arabidopsis using a ‘one‐step’ TYMV‐derived vector
Authors: Pflieger Stéphanie , Blanchet Sandrine , Camborde Laurent , Drugeon Gabrièle , Rousseau Alice , Noizet Mildred , Planchais Séverine , Jupin Isabelle
Published: July 2008

Virus‐induced gene silencing (VIGS) is an important tool for the analysis of gene function in plants. This technique exploits recombinant viral vectors harbouring fragments of plant genes in their genome to generate double‐stranded RNAs that initiate homology‐dependent silencing of the target gene. Several viral VIGS vectors have already been successfully used in reverse‐genetics studies of a variety of processes occurring in plants. Here, we show that a viral vector derived from Turnip yellow mosaic virus (TYMV) has the ability to induce VIGS in Arabidopsis thaliana, accession Col‐0, provided that it carries an inverted‐repeat fragment of the target gene. Robust and reliable gene silencing was observed when plants were inoculated simply by abrasion with intact plasmid DNA harbouring a cDNA copy of the viral genome, thus precluding the need for in vitro transcription, biolistic or agroinoculation procedures. Our results indicate that a 76 bp fragment is sufficient to cause gene silencing in leaves, stems and flowers, and that the TYMV‐derived vector also has the ability to target genes expressed in meristematic tissues. The VIGS vector described here may thus represent an ideal tool for improving high‐throughput functional genomics in Arabidopsis.
Novel clades of chromodomain‐containing Gypsy LTR retrotransposons from mosses (Bryophyta)
Authors: Novikova Olga , Mayorov Vladimir , Smyshlyaev Georgiy , Fursov Michail , Adkison Linda , Pisarenko Olga , Blinov Alexander
Published: July 2008

Retrotransposons are the major component of plant genomes. Chromodomain‐containing Gypsy long terminal repeat (LTR) retrotransposons are widely distributed in eukaryotes. Four distinct clades of chromodomain‐containing Gypsy retroelements are known from the vascular plants: Reina, CRM, Galadriel and Tekay. At the same time, almost nothing is known about the repertoire of LTR retrotransposons in bryophyte genomes. We have combined a search of chromodomain‐containing Gypsy retroelements in Physcomitrella genomic sequences and an experimental investigation of diverse moss species. The computer‐based mining of the chromodomain‐containing LTR retrotransposons allowed us to describe four different elements from Physcomitrella. Four novel clades were identified that are evolutionarily distinct from the chromodomain‐containing Gypsy LTR retrotransposons of other plants.
Plant stress granules and mRNA processing bodies are distinct from heat stress granules
Authors: Weber Christian , Nover Lutz , Fauth Markus
Published: July 2008

Similar to the situation in mammalian cells and yeast, messenger ribonucleo protein (mRNP) homeostasis in plant cells depends on rapid transitions between three functional states, i.e. translated mRNPs in polysomes, stored mRNPs and mRNPs under degradation. Studies in mammalian cells showed that whenever the dynamic exchange of the components between these states is disrupted, stalled mRNPs accumulate in cytoplasmic aggregates, such as stress granules (SGs) or processing bodies (PBs). We identified PBs and SGs in plant cells by detection of DCP1, DCP2 and XRN4, as marker proteins for the 5′→3′ mRNA degradation pathway, and eIF4E, as well as the RNA binding proteins RBP47 and UBP1, as marker proteins for stored mRNPs in SGs. Cycloheximide‐inhibited translation, stress treatments and mutants defective in mRNP homeostasis were used to study the dynamic transitions of mRNPs between SGs and PBs. SGs and PBs can be clearly discriminated from the previously described heat stress granules (HSGs), which evidently do not contain mRNPs. Thus, the role of HSGs as putative mRNP storage sites must be revised.
Relationships between crop yield and weed time of emergence/removal: modelling and parameter stability across environments
Authors: BERTI A , SATTIN M , BALDONI G , DEL PINO A M , FERRERO A , MONTEMURRO P , TEI F , VIGGIANI P , ZANIN G
Published: July 2008

Seventeen Italian experiments relating to maize, soyabean and durum wheat were used to analyse the variability of duration of tolerated competition (DTC) and weed‐free period (WFP) curves across reasonably homogeneous areas. The data sets were analysed by regression analysis using four models relating yield loss to weed density, time of emergence and removal. These models differ in the way they account for the effect of time of weed removal on potential competitiveness. A sigmoidal relationship between these two variables appears necessary. The model with the best overall performance was then used to test the stability of the parameters that give the shape of the curve in relation to time of emergence and removal. This was done by comparing a full model with shape parameters specific to each experiment and a reduced model with a common set of parameters for all the experiments referring to a specific crop. For all three crops, the residual sum of squares of the reduced model did not increase significantly, indicating that, across tested environments, the yield loss caused by mixed weed infestations can be expressed by a single set of parameters relating weed competitivity to time of emergence and removal. For a given area, it should therefore be possible to predict yield loss on the basis of a quite limited set of experiments, thus greatly simplifying the development and use of decision support systems (DSS).
A critique of studies evaluating glyphosate effects on diseases associated with Fusarium spp.
Authors: POWELL J R , SWANTON C J
Published: July 2008

With the large‐scale adoption of glyphosate‐resistant crops in North America, there are concerns that non‐target microbial populations might be affected by increased frequency of glyphosate use. Stimulation of fungal species associated with crop diseases, including Fusarium spp., has been observed in laboratory and glasshouse experiments. Although field surveys in Saskatchewan detected positive associations between the incidence of Fusarium head blight and application of glyphosate formulations, few field experiments have been successful at demonstrating a stimulatory effect of glyphosate on crop diseases, including diseases associated with Fusarium spp. Taken at face value, there is little evidence from experimental field trials to support a causative link between glyphosate and crop diseases associated with Fusarium spp. However, we are concerned that the experimental field trials investigating links between glyphosate and Fusarium spp. are not representative of interactions that occur under actual farming conditions. In addition, inadequate consideration may have been given to microbial ecology during the design and maintenance of these experimental field trials. At this time, there is insufficient evidence to prove or disprove a link between glyphosate and crop diseases associated with Fusarium spp. and this area should receive high research priority, given the rapid and widespread increase in glyphosate use.
Desmodium species and associated biochemical traits for controlling Striga species: present and future prospects
Authors: KHAN Z R , PICKETT J A , HASSANALI A , HOOPER A M , MIDEGA C A O
Published: July 2008

We discovered serendipitously a new and highly effective intervention against Striga spp., including Striga hermonthica (African witchweed), in cereals, which involves intercropping with cattle fodder legumes, Desmodium spp., including D. uncinatum. Although soil shading and additional nitrogen made some contribution to the reduction of S. hermonthica infestation, an allelopathic mechanism associated with the intercrop was a major factor. Root exudates of D. uncinatum contain novel flavonoid compounds, some of which stimulate germination of S. hermonthica and others dramatically inhibit its subsequent development, including radicle growth. Desmodium spp. have been developed as intercrops for both maize and sorghum and are now being evaluated for millet. From the experience with Desmodium spp., there is now the possibility for producing edible legumes suitable for intercropping with maize and other cereals to respond to a broader profile of farmer practices. These legumes would incorporate the powerful S. hermonthica controlling properties of D. uncinatum through feasible breeding programmes, with appropriate contributions from analytical chemistry to plant molecular genetics and biotechnology. In the longer term, it may also be possible to transfer genes associated with the allelopathic attributes to cereals themselves by heterologous gene expression, creating a new generation of parasitic weed‐free cereals.
Which future for weed science?
Authors: FERNANDEZ‐QUINTANILLA C , QUADRANTI M , KUDSK P , BÀRBERI P
Published: July 2008

Weed science is a discipline dealing with a serious biotic threat capable of causing heavy economic, environmental or aesthetic losses to society. In the past, we have been successful in providing efficient, relatively cheap and safe technologies to manage this threat in a variety of situations. We have been able to provide practical advice and options for the end‐users based on a broad scientific knowledge. In order to continue this success, we need to anticipate the future and change faster than the world around us. Numerous opportunities are open to us. Weed science should enter the global climate change arena, getting involved in both mitigation (improving the carbon efficiency of agriculture and forestry) and adaptation (developing effective practices for the new crops, new production systems and the new weeds). We should find adequate answers to the new demands originating from the enlargement of farms and fields, the increased concern about the conservation of biodiversity and the growing consumer demands on food safety. We should look for new clients in non‐agricultural sectors, offering them our proved expertise and know‐how. We should try to exploit the new opportunities arising as a result of cross‐fertilisation of weed science with other disciplines. At the same time, we need to be aware of some threats: the dominance of short‐term commercial and political objectives in setting research agendas, the reduced R&D resources invested in the agrochemical industry in the development of new herbicides and the increasing ‘publish or perish’ pressure in the public research sector.
Allergic rhinitis management pocket reference 2008*
Authors: Bousquet J. , Reid J. , Van Weel C. , Baena Cagnani C. , Canonica G. W. , Demoly P. , Denburg J. , Fokkens W. J. , Grouse L. , Mullol K. , Ohta K. , Schermer T. , Valovirta E. , Zhong N. , Zuberbier T.
Published: July 2008

Allergic rhinitis is a major chronic respiratory disease because of its prevalence, impacts on quality of life and work/school performance, economic burden, and links with asthma. Family doctors (also known as ‘primary care physicians’ or ‘general practitioners’) play a major role in the management of allergic rhinitis as they make the diagnosis, start the treatment, give the relevant information, and monitor most of the patients. Disease management that follows evidence‐based practice guidelines yields better patient results, but such guidelines are often complicated and may recommend the use of resources not available in the family practice setting. A joint expert panel of the World Organization of Family Doctors (Wonca), the International Primary Care Airways Group (IPAG) and the International Primary Care Respiratory Group (IPCRG), offers support to family doctors worldwide by distilling the globally accepted, evidence‐based recommendations from the Allergic Rhinitis and its Impact on Asthma (ARIA) initiative into this brief reference guide.

This guide provides tools intended to supplement a thorough history taking and the clinician’s professional judgment in order to provide the best possible care for patients with allergic rhinitis. A diagnostic Questionnaire specifically focuses the physician’s attention on key symptoms and markers of the disease. When questionnaire responses suggest a diagnosis of allergic rhinitis, a Diagnosis Guide and a simple flowchart then lead the clinician through a series of investigations commonly available in primary care to support the diagnosis. In addition, key aspects of differential diagnosis are illuminated.

According to ARIA, allergic rhinitis may be classified as Intermittent or Persistent, and as Mild or Moderate/Severe. The classification of rhinitis determines the treatment necessary, as set out in an ARIA flowchart included in this guide. The guide also includes information about the strength of evidence for efficacy of certain rhinitis treatments, a brief discussion of pediatric aspects, and a glossary of allergic rhinitis medications to assist the clinician in making medication choices for each individual patient. Finally, many patients with allergic rhinitis also have concomitant asthma, and this must be checked.

The World Organization of Family Doctors has been delegated by WHO as the group that will be taking primary responsibility for education about chronic respiratory diseases among primary care physicians globally. This document will be a major resource in this educational program.
Primary care: the cornerstone of diagnosis of allergic rhinitis
Authors: Ryan D. , Van Weel C. , Bousquet J. , Toskala E. , Ahlstedt S. , Palkonen S. , Van Den Nieuwenhof L. , Zuberbier T. , Wickman M. , Fokkens W.
Published: July 2008

Allergic rhinitis (AR) is a very common disease with over 600 million people (200 million of them with concomitant asthma) worldwide suffering from it. The majority of patients who seek medical advice are seen in primary care. Although there is a selection of guidelines focused on the management of AR, there is a paucity of guidance on how best to identify patients who would most benefit from treatment. The aim of this paper was to review the best practice for primary care with respect to the diagnosis of AR within that clinical environment.
Severe asthma in childhood: assessed in 10 year olds in a birth cohort study*
Authors: Lang A. , Carlsen K. H. , Haaland G. , Devulapalli C. S. , Munthe‐Kaas M. , Mowinckel P. , Carlsen K.
Published: July 2008

Background:  Limited information is available regarding the prevalence of severe asthma in children. The present study aimed at investigating the prevalence of severe asthma in an urban child population; secondarily evaluating the applicability of the chosen definition by clinical characteristics.

Methods:  Children enrolled in the prospective birth cohort; the Environment and Childhood Asthma Study in Oslo; were reinvestigated at the age of 10 years (n = 1019). A representative population based cohort of 616 children [mean age 10.9 (SD 0.9) years] with lung function measurements at birth was used for prevalence estimates, whereas all 1019 children (154 with current asthma) attending the 10‐year follow‐up were included for verification of the definition of severe asthma. Clinical investigations included spirometry, tests of bronchial hyperresponsiveness, skin prick tests and exhaled nitric oxide. Severe asthma was defined as poorly controlled asthma despite treatment with ≥ 800 μg budesonide or equivalent; assessed by a detailed structured interview.

Results:  The population point prevalence at age 10 years of current severe asthma was 0.5% (three of 616) and among children with current asthma 4.5% (three of 67). The 10/154 children identified as suffering from severe asthma more often had severe bronchial hyperresponsiveness (PD20 methacholine <1 μmol) (60%vs 22%, P = 0.015), lower median forced expiratory volume in 1 s/forced vital capacity ratio (93%vs 99%, P = 0.04) and higher body mass index (mean BMI 22.3 vs 18.3, P < 0.001) than nonsevere current asthmatics.

Conclusions:  The prevalence of severe asthma was 0.5% in all 10‐year olds, and 4.5% among current asthmatics. The severe asthma definition applied in this study is supported by results of clinical investigations.
Paediatric anaphylaxis: a 5 year retrospective review
Authors: De Silva I. L. , Mehr S. S. , Tey D. , Tang M. L. K.
Published: July 2008

Objective:  To describe the demographic characteristics, clinical features, causative agents, settings and administered therapy in children presenting with anaphylaxis.

Methods:  This was a retrospective case note study of children presenting with anaphylaxis over a 5‐year period to the Emergency Department (ED) at the Royal Children’s Hospital, Melbourne.

Results:  One‐hundred and twenty‐three cases of anaphylaxis in 117 patients were included. There was one death. The median age of presentation was 2.4 years. Home was the most common setting (48%) and food (85%) the most common trigger. Peanut (18%) and cashew nut (13%) were the most common cause of anaphylaxis. The median time from exposure to anaphylaxis for all identifiable agents was 10 min. The median time from onset to therapy was 40 min. Respiratory features were the principal presenting symptoms (97%). Seventeen per cent of subjects had experienced anaphylaxis previously.

Conclusions:  This is the largest study of childhood anaphylaxis reported. Major findings are that most children presenting to the ED with anaphylaxis are first‐time anaphylactic reactions and the time to administration of therapy is often significantly delayed. Most reactions occurred in the home. Peanut and cashew nut were the most common causes of anaphylaxis in this study population, suggesting that triggers for anaphylaxis in children have not changed significantly over the last decade.
Occupational rhinitis
Authors:   EAACI Task Force on Occupational Rhinitis, Moscato G. , Vandenplas O. , Gerth Van Wijk R. , Malo J. L. , Quirce S. , Walusiak J. , Castano R. , De Groot H. , Folletti I. , Gautrin D. , Yacoub M. R. , Perfetti L. , Siracusa A.
Published: July 2008

The present document is the result of a consensus reached by a panel of experts from European and nonEuropean countries on Occupational Rhinitis (OR), a disease of emerging relevance, which has received little attention in comparison to occupational asthma. The document covers the main items of OR including epidemiology, diagnosis, management, socio‐economic impact, preventive strategies and medicolegal issues. An operational definition and classification of OR tailored to that of occupational asthma, as well as a diagnostic algorithm based on steps allowing different levels of diagnostic evidence, are proposed. The needs for future research are pointed out. Key messages are issued for each item.
Chinese response to allergy and asthma in Olympic athletes
Authors: Li J. , Lu Y. , Huang K. , Wang C. , Lu J. , Zhang C. , Zhong N.
Published: July 2008

China is going to host the Games of the XXIX Olympiad from 8–24 August 2008 in Beijing. The number of athletes and accompanying individuals expected to arrive at China for the Beijing Olympics is estimated at over 10 000 and among them at least 2 000 (20%) are suspected to suffer from respiratory allergies. It is important to monitor the pollen counts and improve air quality in Beijing because Olympic athletes would be exposed to airborne allergens and pollutants during competitions which could hinder peak performance. The main pollen and spore families in Beijing are Artemisia, Ambrosia, Chenopodiaceae and Gramineae. They can reach around 307 000 grains of pollen/1000 m3 of air in August. Economic development in China is usually linked with worsening of air quality. Due to the adoption of various control measures, the ambient air quality in a number of areas in Beijing has actually improved. The ambient air TSP and SO2 levels in Beijing have been decreasing in the last decade. However, ambient air NOx level has been increasing due to the increased number of motor vehicles. Nevertheless, dedicated medical facilities in Beijing will provide medical services to athletes and delegations from all over the world during the Beijing Olympic Games.
Delayed‐ and immediate‐type reactions in the atopy patch test with food allergens in young children with atopic dermatitis
Authors: Devillers A. C. A. , De Waard‐van der Spek F. B. , Mulder P. G. H. , Oranje A. P.
Published: July 2008

In recent years, the atopy patch test (APT) has been suggested as an addition in the allergological work‐up of children with atopic dermatitis (AD) and suspected food allergy. We initiated a prospective clinical study in children with AD younger than 3 yr, to evaluate the additional clinical value of the APT next to our own standardized allergological work‐up in case of a suspected food allergy. One hundred and thirty‐five children were included in the study. They were tested using the skin application food test (SAFT), the APT and measurement of specific IgE. The allergens used in the skin tests were freshly prepared food stuffs and included commercially available cow’s milk (CM), the egg white of a hard boiled hen’s egg and mashed peanuts in a saline solution. Allergy was defined using a flowchart incorporating the results from the SAFT, oral challenges (OCs) and elimination and (re)introduction periods. To determine the additional value of the APT next to the SAFT, we analyzed the SAFT negative patients per allergen and used an exact binary logistic analysis to evaluate the simultaneous effects of the APT and measurement of specific IgE, calculating mutually adjusted odds ratios (ORs) for positive APTs and specific IgE levels above 0.70 U/l. We found clinically relevant food allergies in 23% (egg white) to 28% (CM and peanut) of our study population. Positive SAFT reactions were observed in 14% (peanut), 16% (egg white) and 21% (CM) of our patient population. Next to the SAFT, we did not observe a significant additional value of the APT for the diagnosis of CM or egg white allergy, but we did find a significant additional value for the diagnosis of peanut allergy (OR = 11.56; p < 0.005, 2‐sided). In clinical practice this statistically significant value does not exclude the need for OC and controlled elimination and (re)introduction periods due to the presence of false‐negative as well as false‐positive results in the APT. In conclusion, we could not find enough support for the current addition of the APT to our standardized allergological work‐up in young children below the age of 3 yr with AD and suspected food allergy. At the moment the additional value of the classical delayed‐type APT next to the SAFT seems to be very limited at best in this study population and does not justify the time‐consuming nature of the skin test.
New visions for atopic eczema: An iPAC summary and future trends
Authors: Rancé Fabienne , Boguniewicz Mark , Lau Susanne
Published: July 2008

Atopic eczema (AE) is a chronic inflammatory skin disease characterized by pruritus, dry skin and an ongoing course of exacerbations and remissions. AE is a common disorder in children with a worldwide cumulative prevalence of 15–20% in this age group. AE has a strong familial predisposition. While AE is a complex disease with multiple gene involvement, recent interest has focused on genes involved in skin barrier/epidermal differentiation and in immune response/host defense. Recent developments and future directions on pathogenesis, diagnosis, natural course and prognosis are discussed.
The herbicide flumioxazin stimulates pathogenesis‐related gene expression and enzyme activities in Vitis vinifera
Authors: Castro Antonio Jesús , Saladin Gäelle , Bézier Annie , Mazeyrat‐Gourbeyre Florence , Baillieul Fabienne , Clément Christophe
Published: July 2008

In this work, the capacity of the soil‐applied herbicide flumioxazin (fmx) to trigger defence mechanisms was assessed using 6‐week‐old in vitro grown Vitis vinifera L. plantlets. Time‐course studies demonstrated that the herbicide induced the expression of basic β‐1,3‐glucanase (Vvglu), basic chitinase (Vvchit1b) and PR10 (VvPR10.3) genes encoding three pathogenesis‐related (PR) proteins involved in grapevine defence against pathogens. Thus, all transcripts accumulated in grapevine tissues to reach maximum values after 24–72 h of herbicide exposure, except for VvPR10.3 gene expression, which was induced in roots and stems but not in leaves. Induction of PR genes was observed to a greater extent in roots and leaves, and its intensity diminished in the stems although still remained noteworthy. The activities of β‐1,3‐glucanase and chitinase enzymes significantly increased in the whole plant after herbicide exposure and were still stimulated 21 days after the beginning of treatments. Similarly, the most remarkable effect occurred in roots. However, all enzyme activities tested were stimulated in the upper aerial tissues as well, indicating that fmx or a derived product acts systemically, likely via root uptake.
Overexpression of the apple alcohol acyltransferase gene alters the profile of volatile blends in transgenic tobacco leaves
Authors: Li Dapeng , Shen Jin , Wu Tao , Xu Yunfeng , Zong Xiaojuan , Li Dequan , Shu Huairui
Published: July 2008

Alcohol acyltransferases (AATs) are key enzymes in ester biosynthesis. Previous studies have found that AAT may be a stress‐related gene. To investigate further the function of the apple alcohol acyltransferase gene (MdAAT2), transgenic tobacco plants overexpressing MdAAT2 were generated. Gas chromatography–mass spectroscopy analysis showed that the volatile blends were altered in these transgenic tobacco leaves. Although no apple‐fruity volatile esters were detected in transgenic tobacco leaves, methyl caprylate, methyl caprate, and methyl dodecanoate were newly generated, and the concentrations of methyl benzoate and methyl tetradecanoate were significantly increased, suggesting that MdAAT2 may use medium‐chain fatty acyl CoA and benzoyl‐CoA as acyl donors together with methanol acceptors as substrates. Surprisingly, the concentrations of linalool were significantly increased in transgenic tobacco leaves, which may mediate the repellent effect on Myzus persicae (Sulzer) aphids. Using methyl jasmonate (MeJA) and wounding treatments, we found that MdAAT2 may substitute for the partial ability of MeJA to induce the production of linalool in transgenic plants. These data suggest that MdAAT2 may be involved in the response to the MeJA signal and may play a role in the response to biotic and abiotic stress.
Extent of hepatitis E virus elimination is affected by stabilizers present in plasma products and pore size of nanofilters
Authors: Yunoki M. , Yamamoto S. , Tanaka H. , Nishigaki H. , Tanaka Y. , Nishida A. , Adan‐Kubo J. , Tsujikawa M. , Hattori S. , Urayama T. , Yoshikawa M. , Yamamoto I. , Hagiwara K. , Ikuta K.
Published: July 2008

Background and Objective  To investigate the physico‐chemical properties of hepatitis E virus (HEV) with regard to inactivation/removal, we have studied four isolates with respect to sensitivity to heat during liquid/dry‐heating as well as removal by nanofiltration.

Materials and Methods  Hepatitis E virus in an albumin solution or phosphate‐buffered saline (PBS) was liquid‐heated at 60°C for a preset time. HEV in a freeze‐dried fibrinogen containing stabilizers was also dry‐heated at 60 or 80°C for a preset time. In addition, to clarify the removal of HEV, the purified virus in PBS was filtered using several types of virus‐removal filter (nanofilters) that have different pore sizes. HEV infectivity or genome equivalents before and after the treatments were assayed by a semiquantitative cell‐based infectivity assay or quantitative polymerase chain reaction assay, respectively.

Results  Hepatitis E virus isolates in albumin solutions were inactivated slowly at 60°C for 5 h and the resultant log reduction factor (LRF) was from 1·0 to ≥ 2·2, whereas the virus in PBS was inactivated quickly to below the detection limit and the LRF was ≥ 2·4 to ≥ 3·7. The virus in a freeze dried fibrinogen containing trisodium citrate dihydrate and l‐arginine hydrochloride as stabilizers was inactivated slowly and the LRF was 2·0 and 3·0, respectively, of the 72 h at 60°C, but inactivated to below the detection limit within 24 h at 80°C with an LRF of ≥ 4·0. The virus in PBS was also confirmed as to be approximately 35 nm in diameter by nanofiltration. These results are useful for evaluating viral safety against HEV contamination in blood products.

Conclusion  The sensitivity of HEV to heat was shown to vary greatly depending on the heating conditions. On the other hand, the HEV particles were completely removed using 20‐nm nanofilters. However, each inactivation/removal step should be carefully evaluated with respect to the HEV inactivation/removal capacity, which may be influenced by processing conditions such as the stabilizers used for blood products.
Sperm Quantity Explains Age‐Related Variation in Fertilization Success in the Hide Beetle
Authors: Hale Joshua M. , Elgar Mark A. , Jones Therésa M.
Published: July 2008

Age‐related variation in sperm quality and quantity may have a dramatic impact on female fecundity and fertilization success. Despite this, the relationships between these parameters are rarely investigated. Moreover, studies exploring age‐related variation in male mating success generally fail to consider the entire lifespan of an individual male; instead they restrict analyses to a small number of defined age classes. As a consequence they are unable to assess the impact of early and late life history components on male reproductive success. In this study, we explore these questions using the hide beetle, Dermestes maculatus, a model species for investigating age‐related male mating success. We first employed a longitudinal design to explore whether patterns of sperm transfer and subsequent reproductive success varied over the reproductive lives of a cohort of males. Secondly, we investigated age‐related variation in sperm viability, a surrogate measure of sperm quality. Finally, we combined these data and assessed whether the observed patterns of sperm transfer were correlated with fertilization success. We found that the quantity of sperm varied with male age: the amount of sperm transferred to a female increased with male age until 9 wk and then started to decline. Similarly, female fecundity and fertilization success were related to male age: females mating with males when they were relatively young (1 wk) or relatively old (13 wk) suffered reductions in fecundity and fertilization. Our data suggest that fertilization success is driven at least in part by the quantity of sperm transferred during mating.
Smoke‐Water and a Smoke‐Isolated Butenolide Improve Germination and Seedling Vigour of Eragrostis tef (Zucc.) Trotter under High Temperature and Low Osmotic Potential
Authors: Ghebrehiwot H. M. , Kulkarni M. G. , Kirkman K. P. , Van Staden J.
Published: July 2008

The seeds of Eragrostis tef are often exposed to high temperatures and low water availability during unfavourable climatic conditions. This affects germination and seedling stand establishment of the crop. Smoke is currently widely studied for its stimulatory role in seed germination. The effect of smoke‐water and a smoke‐isolated butenolide was investigated on E. tef seed germination and seedling growth at different temperatures, light conditions and osmotic potentials. Treating E. tef seeds with smoke‐water and butenolide increased the percentage germination relative to the control at all tested temperatures. These treatments significantly improved seedling length and the vigour index at 25, 30, 35 and 40 and 30/15 °C. Smoke‐water and butenolide increased percentage imbibition from high to low osmotic potential. In comparison with the control, smoke‐water‐ and butenolide‐treated seeds of E. tef showed higher percentage germination with decreasing osmotic potential. Smoke‐water treatment exhibited significantly longer and more vigorous seedlings than the control between 0 and −0.30 MPa osmotic potential. The findings of this study suggest the possibility of using smoke treatments for minimizing E. tef seedling losses at elevated temperatures and water stress.
Sex pheromones in three Bradysia species (Dipt., Sciaridae): novel bioassays with female body extracts and fractions
Authors: Frank J. , Dettner K.
Published: July 2008

Females of the fungus gnat species Bradysia difformis, Bradysia optata and Bradysia tilicola are able to produce sexual attractants. In males, the female extracts elicit species‐specific courtship behaviour and attraction in an olfactometer bioassay. Attractiveness of the sex pheromone extracts seems to differ in the investigated species, being highly attractive for males in B. difformis and only moderately attractive in B. tilicola. Female B. difformis are attractive from late pupal stages until death of the imago. In contrast, female B. optata and B. tilicola are not attractive to males before emergence from the pupa and attractiveness decreases in older females. The pheromones seem to be located on the surface of several body compartments of freshly emerged females. Sexual pheromones of all three species represent multicomponent blends and can be separated in several fractions via thin layer chromatography (TLC). Males of all species show courtship behaviour when placed on developed TLC sheets, indicating the position of the biologically active compounds. In B. difformis and B. optata, the most non‐polar TLC fraction is attractive to males, whereas the single fractions of B. tilicola‐pheromone elicited almost no attraction of males.
Effect of generalist insect herbivores on introduced Lepidium draba (Brassicaceae): implications for the enemy release hypothesis
Authors: Puliafico K. P. , Schwarzländer M. , Harmon B. L. , Hinz H. L.
Published: July 2008

The enemy release hypothesis (ERH) states that decreased regulation by natural enemies allows plants to increase in distribution, abundance and vigour following their introduction into an exotic range. Invasive plants rarely escape herbivory entirely, and for hoary cress [Lepidium draba L. (Brassicaceae)] it has been demonstrated that generalist insect abundance is greater in its introduced North American range than in the native European range. We assessed the role of increased generalist herbivory on hoary cress using representatives of four important herbivore niches commonly found in the introduced range. We experimentally examined the density dependent impact of these herbivores individually and in combination on hoary cress in a series of greenhouse experiments. We found that defoliation of the oligophagous diamondback moth Plutella xylostella (L.) (Lep., Plutellidae) had the strongest and most consistent impact, while damage by the stem‐mining weevil Ceutorhynchus americanus Buchanan (Col., Curculionidae) tended to have the highest per capita effect. Plant response to feeding by the oligophagous crucifer flea beetle Phyllotreta cruciferae (Goeze) (Col., Chrysomelidae) was minor despite obvious feeding damage, and the impact of the polyphagous tarnished plant bug Lygus hesperus Knight (Het., Miridae) was negligible. In multiple‐species experiments, herbivore impacts were usually additive. In general, we found that hoary cress can tolerate high densities of oligophagous insect herbivory and effectively resisted attack by the polyphagous L. hesperus, but also the oligophagous C. americanus. Our results indicate that a combination of plant resistance and tolerance allows hoary cress to withstand increased generalist herbivore load in its introduced range, consistent with the predictions of the ERH.
Towards Ethically Improved Animal Experimentation in the Study of Animal Reproduction
Authors: Blache D , Martin GB , Maloney SK
Published: July 2008

Contents

The ethics of animal‐based research is a continuing area of debate, but ethical research protocols do not prevent scientific progress. In this paper, we argue that our current knowledge of the factors that affect reproductive processes provides researchers with a solid foundation upon which they can conduct more ethical research and simultaneously produce data of higher quality. We support this argument by showing how a deep understanding of the genetics, nutrition and temperament of our experimental animals can improve compliance with two of the ‘3 Rs’, reduction and refinement, simply by offering better control over the variance in our experimental model. The outcome is a better experimental design, on both ethical and scientific grounds.
Functional Differences in the Growth Hormone and Insulin‐like Growth Factor Axis in Cattle and Pigs: Implications for Post‐partum Nutrition and Reproduction
Authors: Lucy MC
Published: July 2008

Contents

Growth hormone (GH) and insulin‐like growth factor‐I (IGF‐I) control growth and lactation in cattle and swine. Insulin participates in the endocrinology of growth and lactation because insulin and GH are antagonistic in their actions. Dairy cows experience a period of negative energy balance during the first 4–8 weeks post‐partum. During this period, their somatotropic axis (comprised of GH, the GH receptor and IGF‐I) becomes uncoupled and there is elevated GH and diminished IGF‐I in the circulation. Blood insulin concentrations are low as well. Sows are different from dairy cows because their somatotropic axis remains coupled during lactation and both GH and IGF‐I are elevated. Nonetheless, sows that become catabolic during lactation will have reduced IGF‐I concentrations. Sows are inseminated after weaning so their metabolic state is different from post‐partum beef and dairy cows that are inseminated when they are lactating. Dairy cows are fed ad libitum and naturally have low IGF‐I during lactation. Sows have elevated IGF‐I when they are well‐fed. A threshold of IGF‐I protein in follicular fluid may be met by local ovarian (paracrine/autocrine) and endocrine sources of IGF‐I. Nutritionally induced changes in insulin and in liver IGF‐I secretion that arise from perturbations of the somatotropic axis have a direct effect on the ovary through the endocrine actions of insulin and IGF‐I. Sows and cows that are nutritionally compromised have low concentrations of insulin and IGF‐I in their blood and this theoretically reduces ovarian responsiveness to gonadotropins. Although sows are inseminated after weaning, there appear to be carry‐over effects of the previous lactation on the ovarian follicular populations that develop after the sow is weaned. Understanding the mechanisms through which metabolic hormones control ovarian function may lead to improved reproductive management of both pigs and cattle because lactation and post‐partum reproduction are closely tied in both species.
Seasonality of Reproduction in Mammals: Intimate Regulatory Mechanisms and Practical Implications
Authors: Chemineau P , Guillaume D , Migaud M , Thiéry JC , Pellicer‐Rubio MT , Malpaux B
Published: July 2008

Contents

Farm mammals generally express seasonal variations in their production traits, thus inducing changing availability of fresh derived animal products (meat, milk and cheese) or performances (horses). This is due to a more or less marked seasonal birth distribution in sheep and goats, in horses but not cattle. Birth peak occurs at the end of winter‐early spring, the most favourable period for the progeny to survive. Most species show seasonal variations in their ovulation frequency (presence or absence of ovulation), spermatogenic activity (from moderate decrease to complete absence of sperm production), gamete quality (variations in fertilization rates and embryo survival), and also sexual behaviour. The intimate mechanism involved is a complex combination of endogenous circannual rhythm driven and synchronized by light and melatonin. Profound and long‐term neuroendocrine changes involving different neuromediator systems were described to play a role in these processes. In most species artificial photoperiodic treatments consisting of extra‐light during natural short days (in sheep and goats and mares) or melatonin during long days (in sheep and goats) are extensively used to either adjust the breeding season to animal producer needs and/or to completely overcome seasonal variations of sperm production in artificial insemination centres. Pure light treatments (without melatonin), especially when applied in open barns, could be considered as non‐invasive ones which fully respect animal welfare. Genetic selection could be one of the future ways to decrease seasonality in sheep and goats.