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PubMed2004

Allergenic airborne grass pollen in Szczecin, Poland.

Grass pollens are known as very potent aeroallergens. The aim of the study was to analyse the grass pollen season in Szczecin (western Poland) in the years 2000-2003 and to establish a relationship between the meteorological conditions and the pollen counts of Poaceae. The meteorological parameters analysed were the maximum and mean air temperature, relative humidity, amount of precipitation and wind speed. Measurements were performed mainly by the volumetric method. In parallel, gravimetric monitoring was conducted in 4 Szczecin city districts in order to establish the spatial distribution of pollen in aeroplankton. Pollen seasons were defined as the periods in which 95 % of the total catch occurred. In the 4 years studied, the lowest concentration of grass pollen was observed in 2000 with the maximum value of 123 pollen grains in 1 m3 per 24 h. In subsequent seasons, the concentration of Poaceae pollen increased and the highest concentration of grass pollen, equal to 809 pollen grains in 1 m3 per 24 h was noted in 2003. The majority of Poaceae species have constant periods of pollen release and the high number of their species means that the pollen season is long and lasts from the beginning of May until the middle of September. The longest pollen season was observed in the year 2000 when the lowest pollen count was found. In sensitive persons the symptoms of pollinosis occur after some threshold pollen count value, which for grass is 30 grains in 1 m3 per 24 h. Therefore, the greatest threat from Poaceae pollen allergens is noted from the middle of May and until the end of July, and at the beginning of September. Analysis of the pollen distribution in different Szczecin city districts determined by the gravimetric method, has shown that the highest exposure to grass pollen allergens occurs in the districts Zelechowa and Sródmieście, in the area with parks, villas and gardens or garden allotments. However, in the pollen season the threshold Poaceae pollen count value is usually exceeded in the entire city. Statistically significant correlations have been found between the grass pollen count in the air and the maximum wind speed, air temperature, amount of precipitation and relative air humidity. The pollen count of grass is determined by the diversity of local flora and weather conditions, especially by the air temperature and relative humidity.

Allergens↗
PubMed1977

[Grass pollen in Munich air. Preparations for a forecast (author's transl)].

To forecast pollen concentrations of the air of a particular place the following data of the area in question should be known: The basic grass pollen content of the air from volumetric measurements made during several years and its mean seasonal changes; the mean daily grass pollen content of 1 m3 of air and its changes, especially at the beginning of the main grass pollen season; the influence of temperature, humidity, precipitation and wind speed on the grass pollen content; weather forecast of the day for which the pollen forecast is to be made and the grass pollen content of the previous day; the composition of the grass flora in the surroundings and the state of flowering of the main components of the grass flora. These data for the city of Munich are presented and discussed. In addition the grass pollen content in the air during the summers of 1975 and 1976 is compared with allergic complaints of 96 and 45 persons respectively.

Air Movements↗
PubMed1993

cDNA cloning of a major allergen from timothy grass (Phleum pratense) pollen; characterization of the recombinant Phl pV allergen.

We isolated a cDNA encoding a major grass pollen allergen from a timothy grass (Phleum pratense) pollen expression cDNA library using allergic patients' IgE. The complete cDNA encoded an allergen that binds IgE from about 80% of grass pollen-allergic patients. Significant sequence homology was found to other major grass pollen allergens from Kentucky bluegrass (Poa pratense) as well as from rye grass (Lolium perenne) which originally were believed to form different identities. Using different monoclonal and polyclonal antibodies raised against group V allergens we identified the recombinant protein as a group V allergen from timothy grass, Phl p V. In IgE-binding studies it is demonstrated that the rPhl p V allergen can be used to block binding of patients' IgE to natural group V isoallergens on two-dimensional immunoblots. IgE inhibition experiments show that up to 60% of grass pollenspecific IgE can be preadsorbed with the rPhl p V allergen from patients sera. The purified rPhl p V induced specific histamine release of blood basophils from grass pollen-allergic patients. This emphasizes the usefulness of the rPhl p V for diagnostic and therapeutic purposes and corroborates the view that specific diagnosis and therapy of type l allergy could be performed with a limited panel of relevant recombinant allergens.

Amino Acid Sequence↗
PubMed1992

Alkaloid toxins in endophyte-infected grasses.

Grasses infected with clavicipitaceous fungi have been associated with a variety of diseases including classical ergotism in humans and animals, fescue foot and summer syndrome in cattle, and rye-grass staggers in sheep. During the last decade it has been recognized that many of these fungal infections are endophytic; a fungal endophyte is a fungus that grows entirely within the host plant. Inspection of field collections and herbarium specimens has revealed that such infections are widespread in grasses. The chemistry associated with these grass-fungal interactions has proved to be interesting and complex, as each grass-fungal pair results in a unique "fingerprint" of various alkaloids, of which some are highly toxic to herbivores. In many cases the presence of an endophyte appears to benefit the plant by increasing drought resistance, or by increasing resistance to attack by insects, thus improving the overall survivability of the grass. This review will focus on alkaloids that have been reported in endophyte-infected grasses.

Acremonium↗
PubMed1996

Analysis of Fusarium causing dermal toxicosis in marram grass planters.

In the European coastal dunes, marram grass (Ammophila arenaria) is planted in order to control sand erosion. In the years 1986 to 1991, workers on the Wadden islands in the Netherlands planting marram grass showed lesions of skin and mucous membranes, suggesting a toxic reaction. Fusarium culmorum dominated the mycoflora of those marram grass culms that were used for planting. This plant material had been cut and stored for more than one week in the open. The Fusarium toxin deoxynivalenol (DON) was detected in the suspect marram grass culms. Isolated F. culmorum strains were able to produce DON in vitro in liquid culture as well as in experimentally inoculated wheat heads. Pathogenicity tests, toxin test as well as RAPD analysis showed that the F. culmorum strains were not specialized for marram grass but may form part of the West-European F. culmorum population infecting cereals and grasses. Storage on old sand-dunes with plant debris may have led to the high occurrence of F. culmorum and contamination with DON. Marram grass culms should be obtained from young plantings on dunes on the seaward slopes and cut culms should not be stored.

Adult↗
PubMed1977

[Studies on antigenic relationship between grass- and cult. rye pollens by skin-test, RAST and RAST-inhibition-test in patients with pollinosis (author's transl)].

Skin tests on patients suffering from pollinosis suggest frequently an antigenic relationship between various grass and cult. rye pollens. This problem was further studied using both, RAST and RAST inhibition test. The tests were performed with commercial grass pollen discs as well as with self-prepared disc labeled with cult. rye pollens and a combination of various grass antigens. Good agreement was found between self-made and commercial (single antigen) grass pollen discs (95.9%). RAST and skin test correlated also extremely well (92.3%). Mutual inhibition between grass and cult. rye pollens was measured by RAST inhibition test using self-prepared discs. High antigenic relationship between grass and cult. rye pollens was found, however, it could be demonstrated that the antibody pattern varies and contains "grass specific" antibodies.

Antibody Specificity↗
PubMed2004

Tall fescue EST-SSR markers with transferability across several grass species.

Tall fescue (Festuca arundinacea Schreb.) is a major cool season forage and turf grass in the temperate regions of the world. It is also a close relative of other important forage and turf grasses, including meadow fescue and the cultivated ryegrass species. Until now, no SSR markers have been developed from the tall fescue genome. We designed 157 EST-SSR primer pairs from tall fescue ESTs and tested them on 11 genotypes representing seven grass species. Nearly 92% of the primer pairs produced characteristic simple sequence repeat (SSR) bands in at least one species. A large proportion of the primer pairs produced clear reproducible bands in other grass species, with most success in the close taxonomic relatives of tall fescue. A high level of marker polymorphism was observed in the outcrossing species tall fescue and ryegrass (66%). The marker polymorphism in the self-pollinated species rice and wheat was low (43% and 38%, respectively). These SSR markers were useful in the evaluation of genetic relationships among the Festuca and Lolium species. Sequencing of selected PCR bands revealed that the nucleotide sequences of the forage grass genotypes were highly conserved. The two cereal species, particularly rice, had significantly different nucleotide sequences compared to the forage grasses. Our results indicate that the tall fescue EST-SSR markers are valuable genetic markers for the Festuca and Lolium genera. These are also potentially useful markers for comparative genomics among several grass species.

Base Sequence↗
PubMed2005

Grass evolution inferred from chromosomal rearrangements and geometrical and statistical features in RNA structure.

The grasses (Poaceae) represent a monophyletic lineage that arose about 70 million years ago. The lineage contains about 10,000 species that differ widely in morphology and physiology. Species show striking differences in genome size, a feature important in the context of conservation of gene content and order (synteny and colinearity) and in the extension of genomic information directly from one grass species to another using comparative approaches. Grass diversification has been a contentious issue, as the exact branching order of the various subfamilies has been difficult to establish with standard methods. This motivated an evolutionary study of deep phylogenetic relationships based on the structure of coding and non-coding RNA molecules and on chromosomal rearrangements. Phylogenetic relationships in the grass family were inferred directly from the structure of RNA using cladistic principles and considerations in statistical mechanics. Coded attributes describing topological and thermodynamic information embedded in RNA molecules were treated as linearly ordered multi-state characters and were polarized by fixing the direction of character transformation toward molecular order. Intrinsically rooted phylogenies derived from the structure of signal recognition particle (SRP) RNA, the mRNA encoded by the early nodulation gene enod40, the small subunit of ribosomal RNA (rRNA), and the internal transcribed spacer ITS1 of rRNA established an order for the diversification of major grass lineages, suggesting a sister relationship of the Pooideae and the PACCAD clade. This same conclusion was reached when large-scale chromosomal rearrangements derived from the comparative genetic mapping of cereal genomes were studied. Chromosomal complements aligned in the most parsimonious manner allowed identification and coding of characters depicting chromosomal translocations, insertions, and linkage block arrangements and the reconstruction of phylogenetic trees based on large-scale chromosomal structure. Congruent reconstruction of deep branching relationships using geometrical and statistical features of RNA structure and orthology and large scale chromosomal recombination events support assumptions of polarization in character argumentation, and fail to falsify the claim that extant grass chromosomes can be considered combinations of linkage blocks of an ancestor of the rice genome. Congruence also suggests that the universal tendency toward order in RNA and the search for the most parsimonious organization of be genome architecture appear to be mutually supported drivers of molecular evolution. The study clarifies the relationship of major clades in the grasses, shows that phylogenetic history can be reconstructed effectively from the combinatorial exchange of chromosomal linkage blocks, and reveals considerable phylogenetic signal embedded in the structure of signal polypeptide-coding mRNA molecules, describing an instance where mRNA structure is the subject of strong evolutionary constraint.

Base Pairing↗
PubMed2003

Implications of interveinal distance for quantum yield in C4 grasses: a modeling and meta-analysis.

The distance between veins has the potential to affect photosynthesis in C(4) grasses because photon capture and photosynthetic carbon reduction are primarily restricted to vascular bundle sheath cells (BSC). For example, BSC density should increase as interveinal distance (IVD) decreases, and thus IVD may influence photon capture and photosynthesis in C(4) grasses. The objective of this study is to evaluate the potential importance of IVD to the function of C(4) grasses, and a literature survey is conducted to test the hypothesis that quantum yield of photosynthesis (Phi) increases with decreasing IVD. First, a meta-analysis of Phi and IVD values obtained for 12 C(4) grass species supports this hypothesis as Phi and IVD are significantly negatively correlated (r=-0.61). Second, a regression of carbon isotope discrimination (delta) versus IVD was conducted and the regression equation was used in a simple biochemical model that relates Phi to Delta and leakage of CO(2) from the BSC. The modeling analysis also supports the hypothesis that Phi decreases with increasing IVD in C(4) grasses. C(4) grasses are virtually absent from shaded habitats, and the biochemical model is employed to examine the implications of IVD for shade-tolerance in C(4) grasses. The model predicts that only those species with uncommonly small IVD values are able to tolerate prolonged shade.

Adaptation, Physiological↗
PubMed2006

Once-daily sublingual allergen-specific immunotherapy improves quality of life in patients with grass pollen-induced allergic rhinoconjunctivitis: a double-blind, randomised study.

The effect of sublingual immunotherapy on quality of life (QoL) was examined in patients with grass pollen-induced rhinoconjunctivitis. Patients (n = 855) were randomised to once-daily grass allergen tablets (2,500; 25,000; or 75,000 SQ-T Phleum pratense extract; GRAZAX or placebo. Treatment was initiated 8 weeks before the start of the grass pollen season and continued throughout. If symptoms were present, patients received loratadine or placebo rescue medication. There were three major findings: in patients using loratadine, grass allergen tablets provided QOL benefits over placebo; Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) score was 17% (p = 0.006) and 20% (p = 0.020) greater with 75,000 SQ-T tablet than with placebo at first and second seasonal visit, respectively; in patients not using loratadine, grass allergen tablets improved QoL more than placebo; RQLQ score was 21% greater (p = 0.021) with 75,000 SQ-T tablet at second seasonal visit; grass tablets (without loratadine) had a greater effect on QoL than loratadine alone. RQLQ score was 26% (p = 0.014) greater with 75,000 SQ-T tablets than loratadine at second seasonal visit. These data show that sublingual immunotherapy with grass allergen tablets improves QOL in allergic rhinoconjunctivitis, reduces symptoms, and that this effect is greater than rescue antihistamine alone.

Administration, Sublingual↗
PubMed1993

Molecular characterization of Phl p II, a major timothy grass (Phleum pratense) pollen allergen.

Grass pollen allergens belong to the most important and widespread elicitors of pollen allergy. Using serum IgE from a grass pollen allergic patient, a complete cDNA encoding a group II allergen was isolated from a timothy grass (Phleum pratense) pollen expression library. The deduced amino acid sequence of the Phl p II allergen shows an average sequence identity of 61% with the protein sequences determined for group II/III allergens from rye grass (Lolium perenne) and a sequence identity of 43% with the C-terminal portion of group I grass pollen allergens from different species. A hydrophobic leader peptide similar to leader peptides found in other major grass pollen allergens heads the deduced amino acid sequence, indicating that group II/III grass pollen allergens belong to a family of secreted proteins. Serum IgE specific for Phl p II, detected the protein exclusively in pollen and not in other plant tissues. The recombinant Phl p II was expressed in Escherichia coli and showed similar IgE-binding capacity as the natural allergen.

Allergens↗
PubMed1987

Cross-reactive and unique grass group I antigenic determinants defined by monoclonal antibodies.

As part of a study to probe the immunochemical basis for allergenic cross-reactivity among grass pollens, a series of useful reagents has been prepared. The major grass-pollen allergen, designated group I (GpI), was isolated from five grass pollens (meadow fescue, June grass, sweet vernal grass, redtop grass, and perennial ryegrass). The purified GpI antigens were used to immunize individual groups of BALB/c mice. A total of 123 hybridoma-derived anti-GpI monoclonal antibodies (mAbs) was produced. These mAbs were used to evaluate the antigenic relationship among the GpI antigens by means of two types of ELISA. The experiments revealed a high level of epitope diversity and demonstrated a wide range of antibody specificities. A cross-reactivity ELISA was used to identify and compare antigenic determinants on the GpI molecules, and it was possible to define mAbs with specificities unique for the immunizing allergen and other mAbs that cross-reacted with one or more other members of the test panel of allergens. These murine mAbs reflect the range of specificities present in sera from grass-allergic individuals.

Animals↗
PubMed1989

Characterization with monoclonal and polyclonal antibodies of a new major allergen from grass pollen in the group I molecular weight range.

We have purified a 24/25 kd allergen from orchard grass pollen (Dactylis glomerata) that has an allergenic potency similar to that of the major group I allergen. We provisionally named this allergen grass 4B1 after the monoclonal antibody used for its identification and purification. This monoclonal antibody was obtained by immunizing mice with whole Lolium perenne-pollen extract and by screening the antibody producing hybrids for reactivity with Dactylis glomerata-pollen extract. Grass 4B1 is physicochemically separable from the group I allergen. Polyclonal rabbit antibodies to grass 4B1 do not react with group I allergen or vice versa. Ninety-five sera with IgE antibodies to grass pollen were tested for IgE antibodies to grass 4B1, and greater than 90% was positive in this test. The median response to grass 4B1 was 70% of that to Lol p I.

Allergens↗
PubMed1991

Clinical and immunologic reactivity of patients allergic to grass pollens and to multiple pollen species. I. Clinical and immunologic characteristics.

The heterogeneity of pollen-allergic individuals is well-known but poorly characterized. Twenty-six patients were studied to characterize their immunologic and clinical patterns. Thirteen patients were allergic only to grass pollens, and 13 other patients were allergic to grass-pollen and other pollen species, including Cupressaceae, plane tree, olive, and Parietaria. The IgE response was assessed by the titration of serum total IgE and orchard grass-specific IgE, as well as by IgE immunoblots to orchard-grass pollens. Clinical reactivity was assessed by nasal challenge with orchard-grass pollens before the pollen season and nasal and bronchial symptom-medication scores between April 1 and June 15. Pollen counts were obtained during this period of survey. Polysensitized patients had significantly increased levels of serum total and specific IgE and a greater heterogeneity of IgE immunoblots, suggesting an enhanced qualitative and quantitative IgE immune response. Polysensitized patients had nasal and bronchial symptoms occurring earlier than grass pollen-allergic individuals, confirming the priming effect caused by other plans flowering with an earlier season for both nasal and bronchial mucosa. Alternatively, the early symptoms may be attributable to the tree pollens or might reflect the higher grass-pollen IgE level in the polysensitized group. Bronchial symptoms appeared a few weeks after nasal symptoms. Nasal challenges were similar in both groups, and the severity of nasal symptoms during the season was not significantly different in both groups, suggesting that the intensity of symptoms is not related to the sensitization nor to the IgE immune response of the subjects.

Adolescent↗
PubMed1994

Immunological relationships among group I and group V allergens from grass pollen.

Specific IgE antibodies have been affinity-purified from recombinant grass pollen allergens, and used to identify isoforms of the two major allergens of rye-grass pollen, Lol p I and Lol p V and cross-reactive allergens in other grasses. Lol p I-specific IgE (affinity-purified from the recombinant protein expressed by clone 13R which encodes amino acids 96-240 of Lol p I) identified four isoforms of the allergen. The same probe recognized cross-reactive epitopes in pollen proteins from 14 out of 16 grasses. The allergens identified by Lol p V-specific IgE (affinity-purified from the recombinant protein expressed by clones 12R or 19R which encode the full Lol p V protein) varied more in their physicochemical characteristics than the Group I isoforms. At least eight isoforms of Lol p V were identified by the Lol p V-specific IgE. The same probe recognized cross-reactive epitopes in pollen protein from 13 out of 16 grasses. Group I proteins were identified in grasses from two sub-families of the Poaceae, while the Group V allergens were only identified in pollen of grasses from one sub-family, the Pooideae.

Allergens↗
PubMed1987

Multivariate stochastic modelling of grass fluoride and airborne fluorides.

Stochastic modelling was used to investigate the influence of airborne fluorides (in the case of grass fluoride) and meteorological factors on both grass and airborne fluoride levels, taking into consideration lagged dependence. Using rigorous grass sampling methods, there were indications of a negative relationship between volume of rainfall and grass fluoride concentrations, but no apparent relationship between the time which the leaf was visibly wet and grass fluoride levels. No evidence was found that rainfall washed airborne fluoride from the atmosphere or that wind variables influenced grass fluoride. For one particular experimental site, a multivariate stochastic model, which accounts for 81% of the total variation of the grass fluoride series, is developed.

Journal Article↗
PubMed1990

Plasma electrolyte changes after ingestion of bile extract of the grass carp (Ctenopharyngodon idellus) in rats.

Some Chinese people believe that eating the gallbladder of the grass carp (Ctenopharyngodon idellus) may improve their visual acuity. However, ingestion of grass-carp bile, in severe cases, may kill human beings and experimental animals. The cause of death after eating grass-carp bile was studied in rats. The bile acid fraction was prepared from the n-hexane-insoluble and alcohol-soluble parts of grass-carp and hog bile. The bile extract (6 ml/kg, 15%) was administrated by gastric intubation to conscious female Long-Evans rats. Ingestion of grass-carp bile extract killed all the experimental rats in 2-8 h and was associated with a decrease in blood pressure and an increase in plasma potassium, hydrogen ions, blood urea nitrogen and hematocrit. However, rats that ingested hog bile or saline showed no significant changes in the measured parameters. If the rats were fed cholestyramine-treated grass-carp bile extract, they survived without significant change in the measured parameters. This report demonstrates that a drastic increase in plasma potassium and hydrogen ions probably caused the death of the rats, and also shows that bile acid (alcohol) in grass-carp bile is related to the toxicity.

Animals↗
PubMed2006

Efficacy and safety of sublingual immunotherapy with grass allergen tablets for seasonal allergic rhinoconjunctivitis.

BACKGROUND: Allergen immunotherapy (desensitization) by injection is effective for seasonal allergic rhinitis and has been shown to induce long-term disease remission. The sublingual route also has potential, although definitive evidence from large randomized controlled trials has been lacking. OBJECTIVE: The aim was to confirm the efficacy of a rapidly dissolving grass allergen tablet (GRAZAX, ALK-Abelló, Hørsholm, Denmark) compared with placebo in patients with seasonal rhinoconjunctivitis. METHODS: A longitudinal, double-blind, placebo-controlled, parallel-group study that included 51 centers from 8 countries. Subjects were randomized (1:1) to receive a grass allergen tablet or placebo once daily. A total of 634 subjects with a history of grass pollen-induced rhinoconjunctivitis for at least 2 years and confirmation of IgE sensitivity (positive skin prick test and serum-specific IgE) were included in the study. Subjects commenced treatment at least 16 weeks before the grass pollen season, and treatment was continued throughout the entire season. RESULTS: The primary efficacy analysis showed a reduction of 30% in rhinoconjunctivitis symptom score (P < .0001) and a reduction of 38% in rhinoconjunctivitis medication score (P < .0001) compared with placebo. Side effects mainly comprised mild itching and swelling in the mouth that was in general well tolerated and led to treatment withdrawal in less than 4% of participants. There were no serious local side effects and no severe systemic adverse events. CONCLUSION: Sublingual immunotherapy with grass allergen tablets was effective in grass pollen-induced rhinoconjunctivitis. The tablet was well tolerated with minor local side effects. CLINICAL IMPLICATIONS: The grass allergen tablet represents a safe alternative to injection immunotherapy suitable for home use.

Administration, Sublingual↗