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At least 721 records · Page 40Linked to original sources
PubMed2006

Sex in advertising: dioecy alters the net benefits of attractiveness in Sagittaria latifolia (Alismataceae).

The flowers and inflorescences of animal-pollinated dioecious plants are generally small and inconspicuous in comparison with outcrossing cosexual species. The net benefits of an attractive floral display may be different for dioecious compared to cosexual populations because dioecious species experience a more severe reduction in pollen delivery when pollinators forage longer on fewer individuals. Here, we develop a model that predicts the decrease in pollen delivery in dioecious relative to cosexual populations from female-female, female-male and male-male visit sequences as the number of individuals visited varies. To evaluate the predictions of our model we conducted a common garden experiment with dioecious and monoecious (cosexual) arrays of the insect-pollinated herb Sagittaria latifolia. We find that, although increasing the advertisements of floral rewards (i.e. increasing floral display) attracts more pollinators to individuals, the probability that these pollinators subsequently deliver pollen to neighbouring plants depends on sexual system. Because the number of individual plants visited per foraging trip did not increase significantly with floral display, the relative pollination success of dioecious versus monoecious populations decreases with increased floral display. We propose that this could explain why dioecy is strongly correlated with reduced floral display among angiosperm species.

Animals↗
PubMed2004

[Risk factors and etiological structure of children's cross-allergic reactions to food products].

Authors of article have recently analyzed the frequency of prevalence and risk factors of cross-reactivity to foodstuffs among 239 children of Abakan in the age of from 6 months till 15 years with skin, respiratory and combined manifestation of atopy. It was proved that risk factors of development of cross-reactivity to food among children of the first years of life are hereditary predisposition to allergic diseases (77.8%) and early introductions of supplemental feeding (44%). Among children older then 7 years pollen sensitization (62%) which preceded the development of cross allergic reactions between separate foodstuffs reaches up to 73.7%, between pollen and foodstuff up to 79% and between epidermal and food up to 10.1%.

Adolescent↗
PubMed1997

Transfer of atopy following bone marrow transplantation.

BACKGROUND: Bone marrow transplantation is an optimal treatment of acute leukemia and aplastic anemia. Allergic manifestations in recipients long after bone marrow transplantation have been reported. A case involving transfer of atopy manifested as food allergy-induced-atopic dermatitis is reported. METHODS: The donor and the patient were investigated by prick tests and RAST to the same food allergens. Single blind, oral challenge to egg documented food allergy in the recipient. RESULTS: A 5-year-old boy without history of atopy developed severe atopic dermatitis after bone marrow transplantation from his HLA-identical sister for acute lymphoblastic leukemia. The patient's course had been marked previously by acute graft versus host disease and cytomegalovirus infection. Immunoallergic evaluation showed an exquisite sensitization to egg, peanut, and soybean. Total IgE was 6400 KIU/L. Concomitantly, the donor showed the same sensitizations. Absolute avoidance resulted in the regression of atopic dermatitis. Subsequently, new sensitization to wheat flour, Dermatophagoides pteronyssinus, birch, and plantain pollens was detected. The donor developed asthma. CONCLUSIONS: This case gives evidence of the transfer of sensitization from donor to recipient. The passive transfer of memory cells within the bone marrow inoculum is a possible mechanism. The current concept of allergy supports down regulation of Th1 cells to the benefit of Th2 cells. Additional deregulation induced by acute graft versus host disease, cytomegalovirus infection, and immunosuppression is possible.

Bone Marrow Transplantation↗
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↗
PubMed1992

Month of birth and allergic disease at the age of 10.

The relationship between month of birth and asthma, hay fever and skin sensitization to mixed grass pollen was analysed in a population-based cross-sectional study in Munich and Bavaria 1989-1990 of 6535 10-year-old children. The relative risk of developing atopic disease is calculated by comparing the prevalence in a single month with the prevalence of all other months. A slightly increased risk of developing allergic skin sensitization for grass pollen (n = 1128) was found for February (odds ratio, 1.3, 95% confidence interval 1.0-1.6), May (1.4, 1.1-1.8) and June (1.3, 1.0-1.6). For hay fever (n = 379) an increase was found for May (1.5, 1.0-2.1) and for allergic asthma (n = 277) for August (1.4, 1.0-2.1). A protective effect was observed for certain months of birth; September for allergic sensitization (0.8, 0.6-1.0), October for and November for hay fever (0.6, 0.3-0.9). The occurrence of hay fever and positive prick test is explained by the seasonal variation of atmospheric grass pollen and the peak in August of asthmatic patients by house dust. Date of birth appears therefore to slightly influence the risk of developing an allergic sensitization and allergic diseases.

Child↗
PubMed2006

Individual versus social pathway to honeybee worker reproduction (Apis mellifera): pollen or jelly as protein source for oogenesis?

Honeybee workers, Apis mellifera, can reproduce in queenless colonies. The production of queen-like pheromones may be associated with their reproductive activity and induce nestmates to respond by feeding them. Such frequent trophallaxis could supply their protein needs for oogenesis, constituting a social pathway to worker reproduction. However, some individuals can develop ovaries without producing queen pheromones. The consumption of protein-rich pollen could be an alternative solitary pathway for them to satisfy this dietary requirement. In order to investigate the way in which workers obtain proteins for oogenesis, we created orphaned worker groups and determined ovarian and pheromonal development in relation to pollen consumption of selected workers. Individuals that did not consume pollen had significantly more developed ovaries and produced significantly more queen mandibular pheromone than workers that fed directly on pollen. Our results suggest that workers producing queen-like secretions are fed trophallactically. However, reproductive workers that lacked queen pheromones had consumed little or no pollen, suggesting that they also obtained trophallaxis. Although pollen consumption might contribute to sustaining oogenesis, it does not appear to be sufficient. Trophallaxis as a means of obtaining proteins seems to be necessary to attain reproductive status in queenless honeybee colonies.

Analysis of Variance↗
PubMed2005

Development and reproduction of Adalia bipunctata (Coleoptera: Coccinellidae) on eggs of Ephestia kuehniella (Lepidoptera: Phycitidae) and pollen.

Due to growing criticism over the use of non-indigenous coccinellids, the two-spot ladybird, Adalia bipunctata (L.), has enjoyed increasing attention for aphid biocontrol in Europe. In the current study, eggs of the Mediterranean flour moth, Ephestia kuehniella Zeller, whether or not supplemented with bee pollen, were evaluated as a factitious food for larvae and adults of A. bipunctata. The predator showed slower larval development and lower survival when reared on live pea aphids, Acyrthosiphon pisum (Harris), than on E. kuehniella eggs. Survival on gamma-irradiated eggs of E. kuehniella was superior to that on frozen flour moth eggs, but other developmental characteristics were similar. Adults of A. bipunctata reared on Ac. pisum were only half as fecund as those offered irradiated or frozen E. kuehniella eggs, but egg hatch was markedly better on live aphids than on flour moth eggs (61 versus 20-27%, respectively). However, when a diet of flour moth eggs was supplemented with frozen moist bee pollen, egg hatch of A. bipunctata was equally as good as on live aphids. Supplementing flour moth eggs with dry pollen did not yield satisfactory results. Only 10% of larvae reached adulthood on moist bee pollen alone and resulting adults weighed less than half as much as those obtained on flour moth eggs. Our findings indicate that A. bipunctata is able to compensate for a suboptimal diet of animal prey by supplementary feeding on flower pollen. It is concluded that pollinivory may be a crucial trait for both the rearing of this natural enemy and its use in biological control programmes.

Animals↗
PubMed2003

Hypoallergenic derivatives of major grass pollen allergens for allergy vaccination.

Grass pollen-induced hay-fever and allergic asthma represent a major health problem in industrialized countries. Whereas the symptoms of these allergic conditions can be controlled by pharmacotherapy, specific immunotherapy vaccination is the only causative approach towards the treatment of these type 1 allergies. Specific immunotherapy is based on administration of increasing amounts of the disease-causing allergens in the form of allergen-containing extracts. However, the extracts used for immunotherapy consist of allergenic and non-allergenic components and may induce severe anaphylactic side-effects upon therapeutic administration. With recent developments in molecular biology of pollen allergens it has become feasible to produce modified hypoallergenic derivatives of recombinant allergens with abrogated or greatly reduced likelihood of anaphylactic side-effects as compared to extract-based treatments. We have demonstrated this concept through reducing the anaphylactic potential of major rye grass pollen allergens by introducing a few point mutations which leave the overall structural fold of the molecule unaltered. These modified forms are expected to make allergen-specific immunotherapy more widely used in the future.

Allergens↗
PubMed2005

Male-fertility genes expressed in male flower buds of Silene latifolia include homologs of anther-specific genes.

When the female plant of Silene latifolia is infected with the smut fungus Microbotryum violaceum, its rudimentary stamens develop into anthers which contain fungus teliospores instead of pollen. To identify genes required for maturation of anthers in S. latifolia, we performed a cDNA subtraction approach with healthy male buds and female buds infected with M. violaceum. We isolated five cDNA clones, which were preferentially expressed in healthy male buds during stages associated with a burst in tapetal activity. These five cDNAs are predicted to encode a mandelonitrile lyase protein (SlMDL1), a strictosidine synthase protein (SlSs), a glycosyl hydrolase 17 protein (SlGh17), a proline-rich protein APG precursor (SlAPG), and a chalcone-synthase-like protein (SlChs). All five genes showed expression in both healthy and fungus-infected male buds, but not expressed in either healthy or infected female buds. The first three genes were highly expressed in both tapetum and pollen grains while the last two genes were expressed only inside the tapetum of male flower buds. Phylogenetic analysis results showed that SlChs and SlGh17 belong to anther-specific subgroups of chalcone-synthase-like genes and glycosyl hydrolase 17 family genes, respectively. Our results suggest that the isolated five genes are related to the fertility of the anther leading to the development of fertile pollen. The smut fungus was not able to induce the expression of the five genes in the infected female buds. This raises the possibility that these genes are under the control of master gene(s) on the Y chromosome.

Amino Acid Sequence↗
PubMed2005

Genetic and molecular identification of genes required for female gametophyte development and function in Arabidopsis.

The plant life cycle involves an alternation of generations between sporophyte and gametophyte. Currently, the genes and pathways involved in gametophytic development and function in flowering plants remain largely unknown. A large-scale mutant screen of Ds transposon insertion lines was employed to identify 130 mutants of Arabidopsis thaliana with defects in female gametophyte development and function. A wide variety of mutant phenotypes were observed, ranging from defects in different stages of early embryo sac development to mutants with apparently normal embryo sacs, but exhibiting defects in processes such as pollen tube guidance, fertilization or early embryo development. Unexpectedly, nearly half of the mutants isolated in this study were found to be primarily defective in post-fertilization processes dependent on the maternal allele, suggesting that genes expressed from the female gametophyte or the maternal genome play a major role in the early development of plant embryos. Sequence identification of the genes disrupted in the mutants revealed genes involved in protein degradation, cell death, signal transduction and transcriptional regulation required for embryo sac development, fertilization and early embryogenesis. These results provide a first comprehensive overview of the genes and gene products involved in female gametophyte development and function within a flowering plant.

Arabidopsis↗
PubMed2003

[Prediction of Japanese cedar pollen emission in a snowy area--surveillance in Hirosaki City].

Japanese cedar is the most common pollinosis allergen in Japan. Predictions of total pollen counts and the first 2 or more days of the Japanese cedar pollen season are beneficial to patients. We developed predictive methods for those 2 factors in Hirosaki. We conducted an atmospheric Japanese cedar pollen survey from 1996 to 2002 in Hirosaki and compared yearly data with the male flowering index counted in 50 cedar trees in the preceding autumn. The male flowering index correlated highly positively with total cedar pollen counts in regression analysis, indicating its usefulness in predicting total pollen counts. Although the number of days from January 1 to the first day of continuous pollen emission showed no correlation with the cumulative maximum temperature during these days, the number of days from the day of first detection of pollen emission (minimum of 1 particle per sq. cm) to the first day of continuous pollen emission correlated highly with the cumulative maximum temperature and cumulative amount of snowfall on these days, suggesting that it is possible to predict the first day of continuous pollen emission by the cumulated daily maximum temperature after the day of first detection of pollen emission.

Air Pollutants↗
PubMed1984

Increased antigen-induced local and systemic mediator release in rhinitis subjects with pulmonary symptoms in the pollen season.

In order to delineate parameters that might discriminate between allergic subjects who develop R or R-P symptoms during natural antigen exposure, 26 subjects allergic to grass or ragweed pollen were classified into R or R-P groups, and then the antigen sensitivity and degree of in vivo mediator release were compared. Antigen-skin sensitivity was quantitated by dilutional skin-test titration, and bronchial sensitivity was quantitated by the amount of inhaled antigen required to receive the FEV1 by 20%. Mediator release was determined by measuring the amount of histamine that was released into skin chambers during antigen incubation and the rise in plasma histamine and serum NCA during antigen-induced bronchospasm. Compared to the 13 R subjects, the 13 R-P subjects were: (1) more sensitive to antigen by both skin-test and inhalation challenge, (2) responded to inhalation of antigen with a greater fall in FEV1 and a greater rise in serum NCA and plasma histamine, and (3) released more histamine into skin chambers after antigen incubation. Even when R and R-P subjects were matched by comparing only subjects with equal skin sensitivity to antigen, greater increases in serum NCA and plasma histamine occurred after inhalation of antigen in the R-P subjects. These data are consistent with the hypothesis that allergic rhinitis subjects who develop pulmonary symptoms during natural pollen exposure are more sensitive to antigen and release more mediators in response to antigen administration. It is therefore possible that the degree of mediator release may be an important factor in determining the pattern of clinical responses to antigen exposure.

Adult↗
PubMed1982

IgE and haemagglutinating antibody production in mice following intranasal immunization with ryegrass pollen.

Repeated intranasal immunization of mice whole ryegrass pollen (RGP) led to the development of high circulating titres of both IgE and haemagglutinating antibodies. Bordetella pertussis vaccine (BPV) was required at the time of initial immunization, although its repeated use did not affect IgE production. Antibody production was maintained at high levels for greater than 4 months. Significant differences were found in the ability of different batches and strains of BPV to induce production.

Adjuvants, Immunologic↗
PubMed1998

Two pine endo-beta-1,4-glucanases are associated with rapidly growing reproductive structures.

Two cDNA clones encoding endo-beta-1,4-glucanases (EGases) were isolated from a radiata pine (Pinus radiata) cDNA library prepared from immature female strobili. The cDNAs PrCel1 (inus adiata cellulase ) and PrCel2 encode proteins 509 and 515 amino acids in length, respectively, including putative signal peptides. Both proteins contain domains conserved in plant and bacterial EGases. The proteins PRCEL1 and PRCEL2 showed strong similarity to each other (76% amino acid identity), and higher similarity to TPP18 (73 and 67%, respectively), an EGase cloned from tomato (Lycopersicon esculentum) pistils, than to any other reported EGases. Northern-blot analyses indicated that both genes displayed a similar pattern of expression. The only significant difference was in the level of expression. In situ hybridizations were used to demonstrate that, within differentiating pine reproductive structures, PrCel1 expression was greatest in microsporangia in pollen strobili and near the developing ovule in the seed strobili. Expression was also found in vegetative tissues, especially in regions experiencing cell elongation, such as the elongating region of root tips. Both proteins have an ability to degrade carboxymethylcellulose in vitro. Genomic-blot analysis indicated the presence of a family of EGase genes in the radiata pine genome, and that PrCel1 and PrCel2 are transcribed from distinct one-copy genes.

Bacterial Proteins↗
PubMed2006

Five-year follow-up on the PAT study: specific immunotherapy and long-term prevention of asthma in children.

BACKGROUND: A 3-year course of specific immunotherapy (SIT) in children with hay fever to grass and/or birch pollen significantly reduced the risk of developing asthma. To investigate the long-term preventive effect, we performed a follow up--2 years after termination of immunotherapy. METHODS: A total of 183 children, aged 6-14 years with grass and/or birch pollen allergy could be investigated 2 years after discontinuation of SIT or no treatment. Conjunctival provocation tests (CPTs) and methacholine bronchial provocation tests were carried out during the season and winter after 5 years. The development of asthma was assessed by clinical evaluation. RESULTS: The significant improvement in hay fever and CPT results observed after 3 years of SIT persisted at the 5-year follow-up. No difference in bronchial responsiveness to methacholine was found after 5 years because of spontaneous improvement during the follow-up period in the control patients. The immunotherapy-treated children had significantly less asthma after 5 years as evaluated by clinical symptoms [odds ratio 2.68 (1.3-5.7)] in favor of SIT for prevention of development of asthma and significantly less patients reported an increase in asthma scores (P < 0.01). CONCLUSION: Immunotherapy for 3 years with standardized allergen extracts of grass and/or birch shows long-term clinical effect and preventive effect on development of asthma in children with seasonal rhinoconjunctivitis.

Adolescent↗
PubMedDate not supplied

CAST-ELISA test--a new diagnostic tool in pollen allergy.

We have applied a recently developed method called CAST-ELISA to evaluate the degree of leukocyte stimulation by specific allergen. This method is based on the measurement of sulfidoleukotriene levels in supernatants taken from previously stimulated peripheral blood leukocytes by specific allergen in the presence of interleukin 3.23 patients with pollinosis entered the study. All of them received no medication during 2 weeks before the test. Leukocytes were isolated by dextran sedimentation followed by single centrifugation. After removal of platelet rich plasma the cells were suspended in stimulation buffer and divided into portions incubated with or without specific allergen for 40 minutes at 37 degrees C. After the incubation, the cells were centrifuged and the evaluation of sulfidoleukotrienes in supernatant was performed. The results were expressed in pg/ml after subtraction of the value of spontaneous sulfidoleukotriene production in portions incubated without allergen. The concentration higher than 200 pg/ml of sulfidoleukotrienes above spontaneous production was regarded as a positive result. We have observed a large spectrum of the leukocyte response upon allergen stimulation. In the initial part of our study we established the optimal allergen concentration. The concentration of sulfidoleukotrienes in supernatants ranged from 10 to 5130 pg/ml. The mean sulfidoleukotriene concentration in the whole group was 1671.69. Positive results were observed in 20 persons. In 3 persons the results of allergen stimulation were negative. We conclude that CAST-ELISA is a reliable method to determine the allergic status in persons with pollinosis.

Allergens↗