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At least 577 records · Page 32Linked to original sources
PubMed2003

Molecular cloning and characterization of hazel pollen protein (70 kD) as a luminal binding protein (BiP): a novel cross-reactive plant allergen.

BACKGROUND: Tree pollen contains many allergens showing cross-reactivity to proteins from pollen, seeds, and fruits of different plant species. Amongst Fagales, responsible for several allergenic responses, hazel provides the best material to study pollen as well as food allergens in one species. The aim of this study was to identify and characterize the physiological function of an allergen from hazel pollen and to determine possible cross-reactivity to proteins from hazelnut. METHODS: Monoclonal antibodies (mAbs) against hazel pollen crude extract were produced. On the basis of IgE binding, demonstrated by sera from patients allergic to hazel pollen, one mAb indicating the best correlation has been selected, and the putative allergen was purified by preparative gel electrophoresis. Isoforms were investigated by two-dimensional PAGE, and for molecular identification a hazel pollen cDNA library was constructed. In situ localization of the allergen during pollen development was performed by immunofluorescence labelling. RESULTS: Immunological staining of crude hazel pollen extract with specific IgE and mAb revealed a 70-kD protein. Immunoblot studies with mAb showed cross-reactive proteins of 70-72 kD in different plant tissues and species. After protein purification, the IgE-binding reactivity of the allergen has been reconfirmed, and two isoforms were detected. Molecular cloning identified the allergen as a luminal binding protein (BiP) of the Hsp70 family with 88-92% sequence identity in various plants. Further immunocytological studies indicated involvement of BiP during pollen development. CONCLUSIONS: Chaperons like BiP play an important role in protein synthesis and in the protection of cellular structures during stress-related processes. Because of their highly conserved protein sequences, we propose that such allergens could be responsible for at least a part of the allergenic cross-reactivity between proteins from different pollens and plant foods.

Allergens↗
PubMed2006

Distinct short-range ovule signals attract or repel Arabidopsis thaliana pollen tubes in vitro.

BACKGROUND: Pollen tubes deliver sperm after navigating through flower tissues in response to attractive and repulsive cues. Genetic analyses in maize and Arabidopsis thaliana and cell ablation studies in Torenia fournieri have shown that the female gametophyte (the 7-celled haploid embryo sac within an ovule) and surrounding diploid tissues are essential for guiding pollen tubes to ovules. The variety and inaccessibility of these cells and tissues has made it challenging to characterize the sources of guidance signals and the dynamic responses they elicit in the pollen tubes. RESULTS: Here we developed an in vitro assay to study pollen tube guidance to excised A. thaliana ovules. Using this assay we discerned the temporal and spatial regulation and species-specificity of late stage guidance signals and characterized the dynamics of pollen tube responses. We established that unfertilized A. thaliana ovules emit diffusible, developmentally regulated, species-specific attractants, and demonstrated that ovules penetrated by pollen tubes rapidly release diffusible pollen tube repellents. CONCLUSION: These results demonstrate that in vitro pollen tube guidance to excised A. thaliana ovules efficiently recapitulates much of in vivo pollen tube behaviour during the final stages of pollen tube growth. This assay will aid in confirming the roles of candidate guidance molecules, exploring the phenotypes of A. thaliana pollen tube guidance mutants and characterizing interspecies pollination interactions.

Arabidopsis↗
PubMed1981

Bioassaying for ozone with pollen systems.

Sensitivity to ozone of pollen germinating in vitro is closely correlated with ozone sensitivity of the pollen parent. Ozone-sensitive and tolerant pollen populations have been identified in tobacco, petunia, and tomato cultivars. The rate of tube elongation can be reversibly slowed or stopped by exposure to low concentrations of ozone. Tube growth rates in the presence of a range of ozone dosages, of pollen populations exhibiting differing ozone sensitivity can be measured and different growth rates can be correlated with ozone dosages. The performance of selected pollen populations can then be used to bioassay ozone in ambient air by introducing the air sample into a growth chamber where ozone-sensitive pollen in growing. Petunia and tobacco pollen are especially useful because they store well at ordinary freezer temperatures and do not require special preparation prior to storage. Modified Brewbacker's growth medium is suitable for growth of both these pollen types. Four useful cultivars are Bel W-3, ozone-sensitive and Bel B, ozone-tolerant tobacco, and White Bountiful, ozone-sensitive and Blue Lagoon, ozone-tolerant petunia. Observations can be made directly by using a TV scanner, or by time lapse or interval photography. Year-round pollen production can be achieved in the greenhouse. Harvested pollen can be tested, packaged, and transported to user facilities without loss of vigor. Pollen populations are inexpensive to produce, respond reliably, and are simple to use as a bioassay for air quality.

Biological Assay↗
PubMed1981

Origins and genetic nonvariability of the proteins which diffuse from maize pollen.

The major function of pollen is to deliver the sperm nuclei to the embryo sac. It does this by germinating and producing a pollen tube and thus provides a relatively simple developmental system for study. Mutants for many pollen functions are accessible, as it is a haploid cell. Mature pollen was fractionated into diffusible proteins, soluble proteins, and proteins insolubly associated with membrane or wall; these protein fractions have been quantified and cataloged by native and SDS polyacrylamide gel electrophoresis. Diffusible proteins are localized in the pollen grain wall whereas soluble proteins are cytoplasmic. The roles of haploid and diploid genomes in specifying these proteins is discussed. Pollen from maximally divergent maize lines was examined for quantitative and qualitative variation in the diffusible proteins. A surprising conservation was found for these proteins indicating some functional role which is, at present, unknown. Initial experiments on the incorporation of 35S-methionine into germinating pollen indicate that major representatives of the diffusible proteins are made within the pollen grain itself. They are presumably included in the pollen wall during development and diffuse out through the pore region. Studies with pollen mRNA and experiments on incorporation of 35S-methionine into developing anthers are underway and will identify the origin of these proteins. A knowledge of the basic developmental biology of maize pollen is a prerequisite to its judicious use as a monitor of environmental mutagens.

Diffusion↗
PubMed2026

Virome metatranscriptomic profiling of birch pollen reveals a diverse viral community.

INTRODUCTION: Viruses are increasingly recognized as integral components of plant-associated biological systems. However, their occurrence and diversity in the reproductive tissues of woody plants remain poorly understood. Birch (Betula spp.) produces large quantities of wind-dispersed pollen that can travel over long distances and may harbour viruses or virus-derived nucleic acids originating from the host plant and/or its associated microbiota. METHODS: We investigated the virome of birch pollen collected from trees growing in central and suburban Berlin, Germany. Metatranscriptomic analyses were performed on pooled pollen samples collected in 2020. These analyses were complemented by RT-PCR screening of individually processed pollen samples collected in 2025 from resampled trees. Primer walking was additionally used to recover an extended genome sequence of a pollen-associated birch toti-like virus. RESULTS: Multiple virus-associated contigs were identified in both pooled metatranscriptomic datasets. These included sequences corresponding to the cherry leaf roll virus (CLRV), the birch idaeovirus (BIV) and the birch toti-like virus (BTLV), as well as additional virus-like contigs provisionally assigned to lineages related to the Orthototiviridae, Botourmiaviridae, Endornaviridae, and Chrysoviridae families. RT-PCR analysis of individually processed pollen samples confirmed the continued detection of CLRV, BIV, and BTLV within the Berlin sampling framework. A near-complete genome sequence was recovered from a pollen-derived BTLV isolate from Berlin, showing high amino acid sequence identity to a recently described leaf-derived BTLV isolate from the United States. DISCUSSION: These findings demonstrate that birch pollen harbours a diverse assemblage of plant- and/or microbiome-associated viruses and expand the known tissue distribution and geographic range of BTLV. More broadly, they establish pollen as an underexplored ecological niche for virome research and provide a foundation for future studies on the ecology, transmission dynamics, and epidemiological significance of pollen-associated and pollen-transmitted viruses.

Betula↗
PubMedDate not supplied

An epidemiological survey on the allergological importance of some emerging pollens in Italy.

Epidemiological studies on the pollens responsible for allergic diseases throughout Italy are lacking. Routine diagnostic panels consist prevalently of grass, Parietaria, weeds, birch, olive and mugwort. Considering the great variety of Italian geographical areas and the observation of the growing allergological importance of new botanical species (e.g., ambrosia), a survey on pollen species considered "minor" was necessary. A panel of "emerging" pollens (birch, hazelnut, alder, hornbeam, cypress, ragweed) and a routine panel were used to skin prick test 2,934 consecutive outpatients with respiratory pathology of suspected allergic origin, in 21 centers across Italy. A specific questionnaire was compiled. It was found that 20.1% of patients did not react to allergens tested, 28.2% were positive for at least one emerging pollen and 51.7% did not react to emerging pollens but tested positive for at least one allergen from the routine panel. The prevalence of single pollen species was related to geographical areas. Ragweed pollen was shown to provoke asthma much more frequently than other pollens. Hitherto scarcely considered pollens play a considerable role in causing allergic diseases in Italy. In the great majority of patients, positivity for these pollens was associated with positivity to the better recognized group of pollen allergens, although in some cases they were the primary pathogenic agent. We suggest that these more recently considered allergens be included in routine diagnostic panels.

Adult↗
PubMed2001

[Pollen surveys in Sapporo for 6 years during 1992 to 1997].

We carried out pollen surveys for 6 years from 1992 to 1997. The method of pollen survey studied was based on the standardization board of air born pollen survey and pollen information in Japan. The pollen samples were collected in Nishioka-area of Toyohira-ku, and Kawazoe-area of Minami-ku in Sapporo. As the pollen sample device. IS Rotary pollen trap was used at Nishioka-area during 1992 to 1994 and at Kawazoe-area in 1993, and Durham's pollen trap was used at Kawazoe-area during 1995 to 1997. The yearly pollen counts were highly fluctuated in trees, particularly Yew (Taxus spp.), Alder (Alnus spp.), Birch (Betula spp.), Pine (Pinus spp.), Fir (Abies spp.), than in Grasses (Gramineae) and Weeds (Polygonaceae, Plantago spp., Artemisia spp., Chenopodiaceae). In addition, the starting date of pollination was widely fluctuated year by year in trees. For instance, the pollen of Birch was confirmed on April 13 in 1993, as the first day in Nishioka-area, while it was on April 28 in 1994. It should be considered that the pollen counts and the starting date of pollination were highly dependent on the weather condition of the previous year and the current year.

Japan↗
PubMed2002

[Chromosome mapping of the S-b locus for F1 pollen sterility in cultivated rice (Oryza sativa L.) with RAPD markers].

S-b is one locus for F1 pollen sterility in cultivated rice (Oryza sativa L.), and the genotype of Taichung 65 (abridged as T65) is Sj/Sj, while its isogenic line, TISL2 is Si/Si at this locus. The results of pollen fertility analysis showed that the pollen of T65 and TISL2 were fertile, but the F1 plant from T65 x TISL2 produced only 40.6% fertile pollens, and the type of sterile pollen was stainable abortive. In F2 population from the cross T65 x TISL2 and BC1F1 population from the cross T65/TISL2/T65, the individuals could be classified into plants with normal pollens and plants with semi-sterile pollens, and the ratio of number of these two types of plants agreed well with the Mendel segregation ratio in 1:1. A total of 53 fertile F2 plants were testcrossed with T65, and all of them showed sterility F1 pollen in. These results demonstrate that the F1 pollen sterility is controlled by a single gene locus S-b, and the allelic interaction of S-bi and S-bj causes the pollen carrying S-bj allele abortive. A total of 187 RFLP markers and 500 RAPD primers were used to screen the polymorphism between T65 and TISL2; only H08-1300 and Y09-1500, two bands amplified by RAPD primer H08 and Y09 were found to be polymorphic. Purified H08-1300 and Y09-1500 were used as probe to hybridize with DNAs from T65 and TISL2, and the results indicated that H08-1300 and Y09-1500 appeared to be single copy in the T65 and TISL2 genome, then the RAPD marker were successfully converted into RFLP marker. The two markers were then used to perform segregation analysis, the results from co-segregation analysis of the genotypes of these two markers and the phenotypes of pollen fertility with F2 population indicated that the S-b was linked to H08-1300 and Y09-1500, and the genetic distances between each marker and the locus were 1.3 cM and 6.6 cM, respectively. To determine the chromosomal position of the S-b locus, H08-1300 was cloned and its two ends were partially sequenced. The homologous comparative analysis of these sequences with published rice sequences with BLAST was performed, and 540 bp of left end sequence of H08-1300 showed 86% homologous with the sequence of rice PAC clone P0033D06 (Accession No. AC079357), and 94% homologies of 101 bp at right end were also observed. Clone P0033D06 had been anchored by RFLP markers R3166 that was located on 18.8 cM position of rice chromosome 5 by Japan Rice Genome Program, which suggested that the S-b locus was mapped on chromosome 5 and tightly linked with R3166. The gene mapping result from this study suggests that using the rice genomic sequences published to determine the chromosome position of RAPD marker, as well as linked genes, would be a useful approach in tagging new genes.

Base Sequence↗
PubMedDate not supplied

Allergenic pollen in the atmosphere of Kayseri, Turkey.

Airborne pollen are important allergens that cause sensitization in allergic rhinoconjunctivitis and asthma. Our aim was to detect the pollen in the atmosphere of Kayseri, to present a pollen calendar, and to detect the allergenic level of these pollen by performing skin tests on patients. Atmospheric pollen were collected by Durham gravimetric samplers in Kayseri between March and November in the years 1996 and 1997. In our study, we observed pollen belonging to 43 different taxa. The total number of pollen per cm2 was found to be 1,330.8 in 1996 and 1,182.5 in 1997. Most of the pollen were from the taxa Pinus, Poaceae, Chenopodiaceae/Amaranthaceae, Cupressaceae, Populus and Quercus in decreasing order. In the skin tests, pollen of the taxa Poaceae and Chenopodiaceae were found to give the most frequent allergic reactions. It was concluded that preparing an airborne pollen calendar could be useful for medical practice. Nevertheless the skin test data did not really correlate with the aerobiologic data, as skin test reactivity is related to the allergenicity of the pollen and not just to ambient exposure.

Adult↗
PubMed2004

Sensitization to common allergens, especially pollens, among children with respiratory allergy in the Trakya region of Turkey.

Asthma and allergic rhinitis are common problems in children and the causative pollen allergens vary according to the geographical area. The aim of this study was to investigate patterns of sensitization to common inhalant allergens, especially pollens, in Turkish children living in the Trakya region and to determine differences between rural and urban areas. Allergen skin testing was prospectively performed on 539 children aged between 4 and 17 years with respiratory allergy. The reaction was considered to be positive if the mean wheal diameter was at least 3 mm greater than that of the negative controls. We detected positive skin reactions in 420 (77.9%) children. Two hundred and eighty-one (52.1%) mite, 277 (51.4%) pollen, 174 (32.3%) mold, 65 (12.1%) animal dander, 12 (2.2%) cockroach and 6 (1.1%) latex skin sensitivities were detected. Among the pollen allergies 173 were cereal pollen (32.1%), 170 grass pollen (31.5%) and 144 tree pollen allergies (26.7%). The most common positive skin test among the pollens was to cultivated wheat (Titicum vulgare) (n = 116, 21,5%), followed by rye grass (Lolium perenne) and orchard grass (Dactylis glomerata). Positive skin reactions to Alternaria, to Candida albicans, and to all pollens except Ulmus competris, Pinus sylvetris, Platanus vulgaris and Tilia platyphyllos, were higher in children with allergic rhinitis than in those with asthma. In children from rural areas, allergic skin reactivity was found to be more common against Candida albicans, sheep dander and all pollens except Corylus avellana, Fraxinus excelsior, Populus alba, Pinus sylvetris, Platanus vulgaris and Chenopodium album, than in urban children. Although Trakya is close to Greece and other Mediterranean countries, this study suggests that the pollens, which sensitize children, are not similar.

Adolescent↗
PubMed2005

Dynamics of airborne pollen particles from inhalation to allergic reaction in the nose.

BACKGROUND: Pollinosis is common worldwide, and has been frequently studied. However, the intranasal dynamics of pollen grains have not yet been documented. The purpose of this study is to elucidate for the first time the dynamics of Japanese cedar pollen (JCP) in the human nose at consecutive steps from inhalation to allergic reaction together with release of Cry j 1 (a major allergenic component of JCP) in the nose. METHODS: A personal sampler collected airborne pollens at head height outdoor on the street, while intranasal pollens after natural or experimental inhalation were collected by irrigation with 200ml saline. Cry j 1 in the supernatant after in vitro incubation with phosphate buffered saline or lavage was determined by enzyme-linked immunoassay. RESULTS: Head-height pollen was 183.0 +/- 43.1/300L/h, with 99% of the inhaled pollens deposited on the nasal surface. Eighty eight% of the inhaled pollen was transported to the out-side of the nose by ciliary function within 3 hours. During this process, considerable amounts of Cry j 1 were released in the nose reaching its plateau within 30 min. When the number of pollen deposited exceeded more than approximately 65 particles, symptoms may occur, leading presumably up to a 74% reduction of the intra-nasal pollen. CONCLUSION: The majority of inhaled airborne pollens was deposited on the nasal mucosal surface and moved out from the nose by mucociliary transportation. During this process, when allergenic substances are released up to a critical concentration, allergic reactions occur leading to expelling of pollen from the nose followed by subsiding of the symptoms.

Adult↗
PubMedDate not supplied

Quantification of airborne birch (Betula sp.) pollen grains and allergens in Krakow.

INTRODUCTION: Birch (Betula sp.) pollen grains are the main cause of seasonal allergies in northern and central Europe. The allergen particles released from the grains are often well distributed in the air. Due to their size, airborne protein particles can easily penetrate into the lower parts of the respiratory airways and may lead to symptoms of asthma. The purpose of this paper was to quantify both Betula sp. pollen grains and allergens in the air. MATERIAL/METHODS: Materials for the investigation were collected in the spring of 2003 with two Hirst-type pollen volumetric traps. Tapes from one trap served for routine birch pollen grain counts, while those from the second for the immunodetection of birch allergens. As birch pollen allergen concentration is seen as dark spots on X-ray films densitometric measurements of the spots were used to quantify birch-pollen antigen concentrations in the air. RESULTS: In most instances, birch pollen counts corresponded with birch pollen allergen levels. However, on several occasions outside the pollen season, only grains or only allergens were detected. Apart from sampling variability, this could be due to faulty/dead pollen grains or submicronic airborne allergen particles. CONCLUSIONS: Counting intact pollen grains and antibody-based detection of allergen molecules are efficient tools in controlled allergen avoidance.

Allergens↗
PubMed2005

Variation in ragweed (Ambrosia artemisiifolia L.) pollen concentration in central Croatia, 2002-2003.

The aim of the study was to determine the onset, duration and termination of the ragweed pollen season; intradiurnal, daily and monthly pollen variation, and possible differences in the occurrence and concentration of ragweed pollen according to sampling sites between 2002 and 2003. The study was conducted at three sampling sites in central Croatia over two pollen seasons (2002 and 2003) using the volumetric method of sampling (Hirst type sampler). In 2003, the ragweed pollen season was by 43 % longer and the percentage proportion of ragweed pollen by 3.4 % greater in comparison with 2002. The total ragweed pollen count and number of days with ragweed pollen concentration greater than 30 pollen grains per m (3) air showed a declining tendency from East to West in both seasons. The intradiurnal peak concentration occurred between 10.00-14.00. The air concentration of ragweed pollen decreased with temperature decline and precipitation. Results of the study provided useful information to individuals allergic to ragweed pollen thereby allowing them to adjust their outdoor activities to avoid contact with the allergen.

Air Pollutants↗
PubMed2005

[Usefulness and practical use of an automatic counter for scattering pollen in spring].

BACKGROUND: In this decade some automatic pollen counters have been developed and showed them useful in some reports. However, the results of automatic counting have not been established. METHOD: We have compared scattering cedar and cypress pollen counts with Durham pollen samplers and a newly developed automatic pollen counter (KH-3000) in the spring from 2000 to 2004 in Tokyo. RESULTS: The relationship between the data of the automatic counter and that of a Durham sampler method is so good that this automatic counter seems useful. The best relationship between two methods was seen from late February to early April in the season of high amounts of pollens scatters. The ratio of pollen counts measured with automatic counter and Durham sampler was about 3.5 on average in the period of enough cedar and cypress pollen dispersion. The avoidance of pollens seems possible with real-time pollen information because reliability of automatic counting is highly evaluated when enough pollens scatter. CONCLUSION: In future, the standardization of automatic counting should be necessary for the accurate evaluation of scattering pollens.

Air Pollutants↗
PubMed1990

The initiation and organization of microtubules in germinating pear (Pyrus communis L.) pollen.

To study microtubule organization in germinating pear (Pyrus communis L., cv., Bartlett) pollen, we removed the pollen wall by freeze-fracturing before treating the resultant pollen protoplasts by conventional immunofluorescence procedures. Results reveal that axial bundles of microtubules are present in the generative cell of both inactivated and activated pollen grains. Microtubules are not present in the vegetative cells of inactivated pollen, but they are present in the vegetative cells of activated pollen grains. Microtubule nucleation occurs in the vegetative cell cortex. Subsequently, the microtubules grow as branching arrays through most of the vegetative cell cortex except at the apertures where they form localized converging or criss-cross patterns. Eventually, in a germinated pollen grain, the microtubules form network-like arrays through most of the pollen grain and a collar of short arrays at the base of the pollen tube. It is suggested that the role of vegetative cell microtubules in pollen germination is indirect through their mediation of the conformational changes in actin organization that are essential for pollen germination.

Fluorescent Antibody Technique↗
PubMedDate not supplied

[Sensitivity to mugwort pollen allergens (Artemisia vulgaris)].

The author has found that 42% of patients with pollinosis had positive skin reactions with mugwort (Artemisia vulgaris) pollen allergens. The majority of tested patients (139 out of 187) were also allergic to grass pollens. However, hypersensitivity to mugwort pollen allergens was isolated and did not accompany grass pollen allergy. The symptoms of pollinosis appeared in this group later than in patients sensitive to grass pollen allergens only (over 21 years of age in 71%). Bronchial asthma was diagnosed in 40% of these patients and allergic skin reactions in 25%. Sensitivity to mugwort pollen allergens was accompanied by the sensitivity to pollen allergens of Graminae family of plants in 80% of cases. The author suggests that sensitivity to mugwort pollen allergens is the second most frequent cause of the pollinosis and is diagnosed too rarely. Failures of desensitization in patients sensitive to pollen allergens of Graminae family of plants may often result from coexisting sensitivity to mugwort pollen allergens as this sensitivity produces not only season but perennial clinical symptoms in nearly 50% of patients. The author discusses also botanical relations and cross-reactions in allergy to mugwort and ragweed pollen allergens.

Cross Reactions↗
PubMed1980

[The determination of the aggressiveness of allergizing types of pollen (author's transl)].

It is a well-known fact that the same amount of various pollen does not cause the same intensity of complaints in different patients with hay fever. This empirically obtained fact has been made objective and applied to the needs of practical allergology. From 1976 to 1978 qualitative and quantitative measurements were carried out on the pollen content of the air in Vienna. At the same time 300 patients with hay fever, who had been thoroughly investigated, made daily recordings of their complaints during the pollen season. A comparison of the two sets of data shows that they correspond well at the time of grass blossoming, yet differ strikingly during the blossoming of trees and herbs. Therefore, the grass pollen count is taken as the basis for any further calculations. By adjusting the amount of all the other types of pollen to the patients' complaints, "correction factors" are established for those types of pollen that are allergologically most important. These correction factors indicate the relative aggressiveness of the individual types in comparison with the grass pollens. In addition, the frequency of sensitization to individual types of pollen was determined in 500 patients at the First Otolaryngological Department of the University Hospital of Vienna. By multiplying the frequency by the correction factor we arrive at the "potency factor" as a measure of the allergological significance of the respective pollen type. The threshold value is indicated as a further parameter. The threshold value is the pollen count per cubic metre of air required to elicit complaints in the average number of sensitized patients. The threshold value for grass pollens is 50 per cubic metre of air; hence the following formula is derived for the determination of the threshold value: (formula: see text). The potency factor and the threshold factor are valuable parameters in the diagnosis, prophylaxis and therapy of hay fever.

Air Pollution↗
PubMed1995

[Seasonal allergic rhinitis and pollen count (a 5-year survey in Budapest)].

The authors compared the seasonal symptoms and the pollen allergen spectrum of pollen allergy with the 5-year aeropalynological data in Budapest. They summarized the average of symptom scores based on the diaries of 105 pollen allergic patients (mainly children) suffering from seasonal allergic rhinoconjunctivitis. The pollen allergen spectrum of the patients was defined. They constructed a local pollen calendar on the basis of the first regular pollen counting in Budapest, which had been done by them for 5 years. The symptom scores grew parallel with the increasing number of grass and ragweed pollen. Tree pollen allergy was found in 7.6 per cent of the patients. In spite of the high number of three pollen in the air in March and April the patients did not have too many complaints according to their symptom scores. Grass pollen allergy was found in 67.6 per cent of the patients and in the grass pollen season (May-July) the characteristic clinical symptoms were expressed. Weeds (in 64.8 per cent of the patients), especially ragweed (in 59.0 per cent of the patients) caused the most significant complaints in the late summer--autumn (August, September and partly October) period. Ragweed and other weeds play an important role in the etiology of seasonal allergic diseases in Hungary. The authors call the attention to the necessity of measures taken against the spread of ragweed.

Adolescent↗