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At least 217 records · Page 12Linked to original sources
PubMed2000

No beneficial effect of isopathic prophylactic treatment for birch pollen allergy during a low-pollen season: a double-blind, placebo-controlled clinical trial of homeopathic Betula 30c.

The objective of this research was to determine if the homeopathic medicine Betula 30c is more effective than placebo at reducing symptoms of pollen allergy in patients sensitive to birch pollen. It was a double-blind, randomized, placebo-controlled trial. Tablets were given both as a prophylactic agent, once a week four weeks before the pollen season and as an acute remedy during the pollen season. The study was done in Oslo, Norway, in May 1996 and involved 73 children, adolescents and young adults from 7 to 25 y of age. Allergy-symptoms were assessed on a visual analogue scale (VAS) by patients or parents. Main outcome measure was the median (with its 95% confidence interval) of the symptom scores for all the treated patients, each day during a 10-day period. The pollen count was very low in 1996, only three days were high enough to provoke allergic symptoms. Surprisingly, the verum treated patients fared worse than the placebo group; they used more rescue medication and had higher symptom scores during these three days. Homeopaths might attribute the findings to a putative aggravation response, but the results certainly do not lend support to the usefulness of the tested prophylactic approach, under conditions of low allergen exposure.

Adolescent↗
PubMed2001

Grass pollen immunotherapy: symptomatic improvement correlates with reductions in eosinophils and IL-5 mRNA expression in the nasal mucosa during the pollen season.

BACKGROUND: Tissue eosinophilia and infiltration by T(H)2-type T cells are characteristic features of allergic rhinitis both after allergen challenge and during natural allergen exposure. Specific immunotherapy inhibits allergen-induced nasal eosinophilia. OBJECTIVES: We sought to assess, in the context of a randomized trial, the relationships between symptomatic improvement after immunotherapy and eosinophil numbers and IL-5 expression in the nasal mucosa during the pollen season. METHODS: Nasal biopsy specimens were taken from 37 adults with severe summer hay fever at baseline (out of season) and at peak season after 2 years of treatment with a depot grass pollen extract or placebo. Biopsy specimens were processed for immunohistochemistry by using mAbs against eosinophils (EG2), T cells (CD3), and IL-2 receptor-positive cells (CD25), as well as for in situ hybridization by using a sulfur 35-labeled antisense riboprobe directed against IL-5. RESULTS: Immunotherapy significantly reduced symptoms (49%, P =.01) and medication requirements (80%, P =.007) compared with placebo. There was a 400% increase (P =.004) in eosinophils during the pollen season in placebo-treated patients, which was inhibited in the immunotherapy group (20% increase, P =.04 between groups). Seasonal increases were also observed for CD25(+) cells (P =.002), CD3(+) cells (P =.02), and IL-5 mRNA-expressing cells (P =.03) in the placebo group but not in the immunotherapy group. A significant correlation was observed between eosinophils and IL-5 expression (r = 0.5, P <.05). Both eosinophils (r = 0.6, P <.02) and IL-5 (r = 0.6, P <.02) correlated with symptoms after immunotherapy. CONCLUSION: Improvement in symptoms after grass pollen immunotherapy may result, at least in part, from inhibition of IL-5-dependent tissue eosinophilia during the pollen season.

Biopsy↗
PubMed2000

Isolation and characterization of pollen coat proteins of Brassica campestris that interact with S locus-related glycoprotein 1 involved in pollen-stigma adhesion.

Adhesion of pollen grains to the stigmatic surface is a critical step during sexual reproduction in plants. In Brassica, S locus-related glycoprotein 1 (SLR1), a stigma-specific protein belonging to the S gene family of proteins, has been shown to be involved in this step. However, the identity of the interacting counterpart in pollen and the molecular mechanism of this interaction have not been determined. Using an optical biosensor immobilized with S gene family proteins, we detected strong SLR1-binding activity in pollen coat extracts of Brassica campestris. Two SLR1-binding proteins, named SLR1-BP1 and SLR1-BP2, were identified and purified by the combination of SLR1 affinity column chromatography and reverse-phase HPLC. Sequence analyses revealed that these two proteins (i) differ only in that a proline residue near the N terminus is hydroxylated in SLR1-BP1 but not in SLR1-BP2, and (ii) are members of the class A pollen coat protein (PCP) family, which includes PCP-A1, an SLG (S locus glycoprotein)-binding protein isolated from Brassica oleracea. Kinetic analysis showed that SLR1-BP1 and SLR1-BP2 specifically bound SLR1 with high affinity (K(d) = 5.6 and 4.4 nM, respectively). The SLR1-BP gene was specifically expressed in pollen at late stages of development, and its sequence is highly conserved in Brassica species with the A genome.

Amino Acid Sequence↗
PubMed2001

Five gametophytic mutations affecting pollen development and pollen tube growth in Arabidopsis thaliana.

Mutant analysis represents one of the most reliable approaches to identifying genes involved in plant development. The screening of the Versailles collection of Arabidopsis thaliana T-DNA insertion transformants has allowed us to isolate different mutations affecting male gametophytic functions and viability. Among several mutated lines, five have been extensively studied at the genetic, molecular, and cytological levels. For each mutant, several generations of selfing and outcrossing have been carried out, leading to the conclusion that all these mutations are tagged and affect only the male gametophyte. However, only one out of the five mutations is completely penetrant. A variable number of T-DNA copies has integrated in the mutant lines, although all segregate at one mutated locus. Two mutants could be defined as "early mutants": the mutated genes are presumably expressed during pollen grain maturation and their alteration leads to the production of nonfunctional pollen grains. Two other mutants could be defined as "late mutant" since their pollen is able to germinate but pollen tube growth is highly disturbed. Screening for segregation ratio distortions followed by thorough genetic analysis proved to be a powerful tool for identifying gametophytic mutations of all phases of pollen development.

Alleles↗
PubMed2002

alpha4-Fucosyltransferase is regulated during flower development: increases in activity are targeted to pollen maturation and pollen tube elongation.

alpha4-Fucosylation represents a final step of protein N- glycosylation. alpha4-fucosylated N-glycans are thought to be involved in cell-to-cell communication and recognition in primates and plants. Nevertheless, in the plant life cycle, the function of alpha4-fucosylation remains largely unknown. To gain an insight into the role of alpha4-fucosylation during development, the study focused on tobacco flowers. It is shown that an increase in alpha(1,4)fucosyltransferase (Fuc-T) activity is only observed during anther development, whereas it remains at a constant but low level (around 20 pmol Fuc h(-1) mg(-1) protein) in the gynoecium and perianth. At least a 4-fold higher activity is detected in mature pollen grains. These data suggest that alpha(1,4)Fuc-T activity is regulated during anther development. Furthermore, alpha(1,4)Fuc-T activity could be required during pollen tube elongation where the activity level peaks at 350 pmol h(-1) mg(-1) protein. Based on enzyme profile and cycloheximide effects on pollen germination and activity, it is hypothesized that the gene encoding alpha4-Fuc-T could be regulated late during pollen development. A potential role of alpha4- fucosylation during pollen tube elongation is also discussed.

Cell Communication↗
PubMed2004

Interactive effects of carbon dioxide, temperature, and ultraviolet-B radiation on soybean (Glycine max L.) flower and pollen morphology, pollen production, germination, and tube lengths.

Plant reproduction is highly vulnerable to global climate change components such as carbon dioxide concentration ([CO(2)]), temperature (T), and ultraviolet-B (UV-B) radiation. The objectives of this study were to determine the effects of season-long exposure to treatments of [CO(2)] at 360 (control) and 720 micromol mol(-1) (+CO(2)), temperature at 30/22 degrees C (control) and 38/30 degrees C (+T) and UV-B radiation 0 (control) and 10 kJ m(-2) d(-1) (+UV-B) on flower and pollen morphology, pollen production, germination, and tube lengths of six soybean genotypes (D 88-5320, D 90-9216, Stalwart III, PI 471938, DG 5630RR, and DP 4933RR) in sunlit, controlled environment chambers. The control treatment had 360 micromol mol(-1) [CO(2)] at 30/22 degrees C and 0 kJ UV-B. Plants grown either at +UV-B or +T, alone or in combination, produced smaller flowers with shorter standard petal and staminal column lengths. Flowers so produced had less pollen with poor pollen germination and shorter tube lengths. Pollen produced by the flowers of these plants appeared shrivelled without apertures and with disturbed exine ornamentation even at +CO(2) conditions. The damaging effects of +T and +UV-B were not ameliorated by +CO(2) conditions. Based on the total stress response index (TSRI), pooled individual component responses over all the treatments, the genotypes were classified as tolerant (DG 5630RR, D 88-5320: TSRI >-790), intermediate (D 90-9216, PI 471938: TSRI <-790 to >-1026), and sensitive (Stalwart III, DP 4933RR: TSRI <-1026). The differences in sensitivity identified among genotypes imply the options for selecting genotypes with tolerance to environmental stresses projected to occur in the future climates.

Carbon Dioxide↗
PubMed1982

Cross-reactivity between Acacia (wattle) and rye grass pollen allergens. Detection of allergens in Acacia (wattle) pollen.

Immunoglobulin E (IgE), directed against components of Acacia (wattle) pollen, has been detected by radioallergosorbent tests (RAST) in the sera of some children and adults who develop allergic symptoms in the presence of flowering Acacia trees in Australia. All these subjects also had high levels of IgE directed against Lolium perenne (rye grass) pollen. Inhibition by RAST showed that most of the IgE molecules which bound to Acacia pollen components also bound to L. perenne pollen extracts, and to Glycoprotein 1, the major allergen of L. perenne pollen. In these assays, the allergens have been immobilized on polyvinyl chloride microtitre trays: the sensitivity of this approach is compared to that of commercial RAST kits.

Acacia↗
PubMed1993

Modifications of PC20 and maximal degree of airway narrowing to methacholine after pollen season in pollen sensitive asthmatic patients.

We examined the effect of cessation of exposure to pollen on non-specific airway responsiveness in 10 grass and/or parietaria pollen sensitive asthmatics. Three methacholine inhalation challenges were performed, the first during pollen season (seasonal period), the second 2 months after the end of season (short time after seasonal period), and the third 5 months after the end of season (long time after seasonal period). The dose-response curves to methacholine were characterized by the PC20 (provocative concentration of methacholine required to produce a 20% fall in FEV1) and maximal response plateau, if possible. A maximal response plateau on the dose-response curve was considered to be present if three or more data points for FEV1 fell within a 5% response range. The challenge was stopped when FEV1 dropped more than 50% or the highest concentration of methacholine (200 mg/ml) was reached. The geometric mean (range) methacholine PC20 increased from 1.08 (0.18-37.22) in the seasonal period to 4.67 (0.71-200) mg/ml during the long time after seasonal period (P < 0.01). On the other hand, in six subjects in whom it was possible to obtain a plateau on at least one challenge, the level of the maximal response decreased from (mean +/- s.e.m.) 44.1 +/- 4.9 in the seasonal period to 30 +/- 4.4 during the long time after seasonal period (P < 0.05). These results suggest that in pollen sensitive asthmatic patients, the cessation of exposure to pollen is associated with a reduction of non-specific bronchial responsiveness (PC20 and maximal degree of airway narrowing to methacholine).

Adolescent↗
PubMed2005

Identification of human T cell epitopes in Japanese cypress pollen allergen, Cha o 1, elucidates the intrinsic mechanism of cross-allergenicity between Cha o 1 and Cry j 1, the major allergen of Japanese cedar pollen, at the T cell level.

BACKGROUND: Pollens from species of Cupressaceae family are one of the most important causes of respiratory allergies worldwide. In Japan, many patients with pollinosis have specific IgE to both pollens of Japanese cypress (Chamaecyparis obtusa) and Japanese cedar (Cryptomeria japonica). The sequences between Cha o 1 and Cry j 1, the major allergens of Japanese cypress and Japanese cedar pollens, respectively, are 80% identical. OBJECTIVE: This study was undertaken to identify T cell epitopes in Cha o 1, and to elucidate the mechanism of cross-allergenicity between Cha o 1 and Cry j 1, at the T cell level. METHODS: T cell epitopes in Cha o 1 were identified by the reactivity of T cell lines, generated from 19 patients, to stimulation with overlapping peptides. The subsets of T cell clones specific to rCha o 1 were determined according to their ability to produce IL-4 and IFN-gamma. Peptide specificities of two T cell clones were determined by stimulation with the peptides from Cha o 1 and Cry j 1. RESULTS: Four dominant and six subdominant T cell epitopes were identified in Cha o 1. While four T cell epitopes, p11-30, p211-230, p251-270 and p331-350, were common to Cha o 1 and Cry j 1, 4 T cell epitopes, p61-80, p71-90, p311-330 and p321-340, were considered to be unique to Cha o 1. The subsets of T cell clones were predominantly of T helper2-type. One T cell clone recognized p16-30, which is common to Cha o 1 and Cry j 1, but another recognized p321-330, which is unique to Cha o 1. CONCLUSION: Presence of both T cells reactive to T cell epitopes common to Cha o 1 and Cry j 1 and T cells specific to T cell epitopes unique to Cha o 1 in patients with pollinosis contributes to prolonged symptoms after the cedar pollen season in March and the following cypress pollen season in April.

Adult↗
PubMed1985

Immunochemical characterization of reference alder (Alnus glutinosa) and hazel (Corylus avellana) pollen extracts and the partial immunochemical identity between the major allergens of alder, birch and hazel pollens.

Dialysed extracts of alder (Alnus glutinosa) and hazel (Corylus avellana) pollens were characterized by immunochemical methods. The alder pollen extract contained at least 33 distinct antigens of which one, antigen 5, was classified as a major allergen, three, antigens 4, 10, and 17, were classified as intermediate allergens and two, antigens 19 and 23, were classified as minor allergens. The molecular weight and pI of the major allergen were determined to be 19,000 D and 5.2, respectively. The hazel pollen extract contained at least 40 distinct antigens, two of which were classified as major allergens, antigens 8 and 13, three as intermediate allergens, antigens 12, 17, and 26, and seven as minor allergens, antigens 6, 11, 16, 18, 29, 39, and 40. The molecular weights and pI's of the major allergens of hazel pollen were determined to be: antigen 8; Mw = 12,000 D, pI = 5.1 and less than 3.5, antigen 13; Mw = 26,000 D, pI = 5.1. Further, crossed line immunoelectrophoresis and tandem crossed immunoelectrophoresis of alder, birch and hazel strongly indicate that there exists an immunochemical partial identity between the major allergens (antigens 5 (alder), 23 (birch), and 13 (hazel)) from these tree pollens.

Allergens↗
PubMed1988

Immunotherapy with partially purified and standardized tree pollen extracts. II. Results of skin prick tests and nasal provocation tests from a three-year double-blind study of patients treated with pollen extracts either of birch or combinations of alder, birch and hazel.

Patients allergic to tree pollen entered a 3-year course of immunotherapy (1980-83) with either birch pollen extracts alone (n = 26) or patient-tailored extracts of birch, alder and hazel pollen (n = 27). The clinical and immunological results of this study are published elsewhere. This paper contains an evaluation of skin prick test and nasal provocation test results. There were no significant differences between the two treatment groups concerning these two parameters. In both groups the allergen-specific sensitivity in the skin showed seasonal variations but a significant decrease. During the years of treatment there was also a significant decrease in the specific sensitivity of the nasal mucosa. With the present demands for purification and standardization of allergen extracts it is of practical and economic interest to know that tree pollen-allergic patients showing positive reactions to birch, alder and hazel extracts can be effectively treated using birch pollen extract alone.

Asthma↗
PubMed1988

Immunotherapy with partially purified and standardized tree pollen extracts. III. Specific IgE response to the major allergens of alder, birch and hazel pollen during immunotherapy.

Patients allergic to pollen from alder, birch and hazel were hyposensitized during a 3-year period with either birch pollen extract alone (n = 24) or a mixture of one or more of alder, birch and hazel pollen extracts (n = 27). The effect of the treatment was evaluated by RAST and tandem crossed-radioimmunoelectrophoresis (tandem-CRIE). The patient' specific IgE response to the major allergens of alder (Aln g I), birch (Bet v I) and hazel (Cor a I and Cor a II), as measured by tandem-CRIE, and the total specific IgE response, measured by RAST, decreased significantly (Pc less than 0.05) during immunotherapy, irrespective of the extract used during the treatment. There was no significant difference (Pc less than 0.05) between the two treatment groups. The results obtained indicate either that birch pollen extract alone is adequate in the treatment of the studied patient group or the patients had been sensitized towards birch pollen alone.

Clinical Trials as Topic↗
PubMed1997

Relevance of pollen-specific IgE levels to the development of Apiaceae hypersensitivity in patients with birch pollen allergy.

A large clinical/serologic study was carried out to determine the prevalence of Apiaceae (carrot, celery, and fennel) hypersensitivity in patients with birch pollen allergy, and to investigate its relationship with apple and hazelnut allergy and with birch pollen-specific IgE levels. A total of 196 birch pollen-hypersensitive patients with oral allergy syndrome (OAS) caused by different vegetable foods were examined in the cross-sectional part of the study. Of this total, 195 patients had apple and/or hazelnut allergy, and 103 had Apiaceae sensitivity; only one patient had Apiaceae allergy alone. Apiaceae-positive patients showed significantly higher birch pollen-specific IgE levels than negative ones (median 13 vs 7 AU/ml; P < 0.0001). The prospective part of the study was performed on 103 birch pollen-hypersensitive patients who were OAS-free at the time of the first visit and were periodically followed-up for OAS. Patients who developed Apiaceae sensitivity showed much higher birch-specific IgE levels than patients who developed apple/hazelnut allergy only (median 15.5 vs 8.5 AU/ml; P < 0.05), whereas those who remained OAS-free showed the lowest specific IgE levels (median 5 AU/ml). This study suggests that most Apiaceae determinants cross-react with apple or hazelnut determinants, whereas only some apple or hazelnut determinants cross-react with Apiaceae-allergenic determinants; moreover, it shows that birch-specific IgE levels heavily influence the onset of OAS as a whole, and probably play a critical role in the development of allergies to distinct vegetable foods as well.

Adolescent↗
PubMed2006

Increased expression of lipoxygenase enzymes during pollen season in nasal biopsies of pollen-allergic patients.

BACKGROUND: Exposure of patients sensitized to pollen triggers development of seasonal allergic rhinitis symptoms (SAR). Eicosanoids are a group of arachidonic acid metabolites contributing to the symptoms of SAR. The aim of this study was to investigate seasonal changes in the expression of enzymes of the eicosanoid pathway in the nasal mucosa of patients with SAR. METHODS: Twenty SAR patients allergic to birch or grass and eight healthy subjects were included in the study. Patients registered rhinoconjunctivitis symptoms and use of rescue medication before and during the pollen season. Nasal biopsies were obtained before and around the peak of the season, sectioned and stained using markers for eosinophils, mast cells, T cells and neutrophils. Antibodies against the following enzymes were also used: cyclo-oxygenase (COX-1, COX-2), 5-lipoxygenase (5-LO), 5-lipoxygenase-activating factor (FLAP), LTA4 hydrolase (LTA4h) and LTC4 synthase (LTC4s). RESULTS: During the pollen season symptoms of rhinoconjunctivitis and medication score increased significantly (P=0.001; P=0.001 respectively). During the pollen season numbers of eosinophils (P=0.02) and cell positive 5-LO (P=0.02), LTC4s (P=0.04) and LTA4h (P=0.02) increased significantly. During season number of mast cells and cells expressing 5-LO and LTA4h were higher in SAR than in healthy controls group (P=0.02; P=0.01; P=0.03 respectively). CONCLUSION: In sensitized patients exposure to pollen allergen results in increased expression of enzymes of the eicosanoid pathway.

5-Lipoxygenase-Activating Proteins↗
PubMed1978

Immunological partial identity and in vitro inhibitory effect of two major timothy pollen allergens to whole pollen extract of four grasses.

Crossed immunoelectrophoresis in various modifications has directly revealed the immunological partial identity between isolated major allergens of timothy pollen (antigens 19 and 25) and the corresponding pollen allergens of false oat, orchard and rye grass, using rabbit antibodies raised against all four grasses. The inhibitory effects of antigens 19 and 25 relative to those of whole pollen extracts have been determined by means of RAST, inhibiting serum pools from selected grass-pollen-allergic patients and using insolubilized whole pollen extracts from the four grasses as allergosorbents. The inhibitory effects of antigens 19 and 25 were determined to be 97, 91, 92 and 73% of those of whole extracts of timothy, false oat, orchard and rye grass, respectively.

Plant Extracts↗
PubMed1986

Quality of timothy pollen (Phleum pratense) from different pollen seasons and different suppliers.

We investigated seven batches of timothy (Phleum pratense) pollen from four different pollen seasons and three different manufacturers in the USA and Europe by several biochemical and immunochemical methods. By measuring the contents of hexoses, proteins and the total allergenic activity using RAST inhibition we could not find any significant differences in quality between pollen of different seasons, different geographical origin and different manufacturers. There were only slight differences in the staining of some protein bands and in peak height of some antigens in isoelectric focusing (IEF), SDS-PAGE and crossed immunoelectrophoresis. These differences in IEF and SDS-PAGE patterns seem to be specific for the pollen samples from the USA and Europe, respectively. We also observed minor differences in IEF immunoprint patterns, mainly for some basic proteins. The allergen patterns in crossed radioimmunoelectrophoresis were very similar, with only minor differences in concentration of the basic allergens. It appears that timothy pollen from different years can be produced in different geographical areas by different manufacturers with fairly constant allergenic activity.

Carbohydrates↗
PubMed1990

IgG4 antibodies in hay fever patients. Difference in IgG4 response to tree pollen and grass pollen allergens.

Total IgE and IgE and IgG4 antibodies to offending allergens were studied in 118 hay fever patients allergic to tree pollen and grass pollen allergens. No difference in the level of total IgE and IgE antibodies was found between these two groups while the IgG4 antibody level was significantly higher in tree pollen allergic patients. It is suggested that the IgG4 antibodies to tree pollen allergens can be stimulated by structurally related allergens of vegetable food and are probably involved in tree pollen-associated food hypersensitivity.

Adolescent↗
PubMed1980

Pollen-stigma interaction in Brassica oleracea: the role of stigmatic proteins in pollen grain adhesion.

The adhesion of pollen grains to the stigmas of Brassica oleracea was assayed after treatment of the stigmas wiuth protease and/or cycloheximide. Treatment with protease alone adversely affected pollen grain adhesion. However, the adhesive properties of the stigma recovered fully if the stigmas were not pollinated until 2 h after treatment. Immersion of the stigmas in cycloheximide after protease treatment prevented any recoveryt of the stigmas' adhesive properties. Cycloheximide treatment alone prevented pollen grain adhesion when pollination occurred later than 1--2 h after treatment but did not affect pollen grain adhesion if pollination occurred immediately after treatment. These results indicated not only that the surface-held proteins of the stigma are involved in pollen grain adhesion, but also that their turnover rate is rapid. Isoelectric focusing of extracts derived from stigmas after protease and cycloheximide treatment showed a marked decrease in staining intensity of 3 protein bands, one of which, a glycoprotein, is known to be present only when the self-incompativility system is fully functional. These observations suggest a specificity of adhesion between higher plant cells in the presence of the cell wall.

Brassica↗