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PubMed1986

[Formation of pollen-induced allergy in guinea pigs after specific immunotherapy with a bacterial allergen].

The investigation was aimed at elucidating the process of the development of allergy to exoallergens (e.g., to linear-leaf wormwood pollen) in the body after desensitization by specific immunotherapy (SIT) with heterologous (staphylococcal) allergen. The study revealed that in staphylococcal allergy the subsequent development of pollen sensitization occurred with greater intensity, and SIT was found to exert no influence on this process. For the first time pollen allergy was found to produce an unfavorable effect on the quality and effectiveness of SIT with heterologous staphylococcal allergen, this effect consisting in the acceleration and intensification of the process leading to the recovery of sensitization to staphylococci. The importance of measures for limiting contacts with heterologous allergens and their elimination during SIT is emphasized.

Allergens↗
PubMed2003

Phytoseiid predators of whiteflies feed and reproduce on non-prey food sources.

Two phytoseiid species, Euseius scutalis (Athias-Henriot) and Typhlodromips swirskii (Athias-Henriot), are able to suppress whitefly populations on single plants and are candidate biological control agents for whiteflies such as Bemisia tabaci (Gennadius). These species can feed on pollen and insect-produced honeydew and these food sources are likely to be available in crops. If the utilization of these food types results in increased reproduction or survival, populations of predators can persist when whitefly prey is scarce or absent. We studied the impact of pollen and whitefly-produced honeydew on the life history of the two phytoseiids. Cattail pollen allowed for survival, development and reproduction of both predators. Whitefly-produced honeydew greatly increased survival of E. scutalis, allowed for development into adulthood and for a sustained low rate of oviposition. The survival of adult T. swirskii was high on cucumber leaf tissue, either with or without pollen or honeydew. Oviposition by adults and juvenile survival of T. swirskii was very low in presence of honeydew. Biological control of whiteflies may benefit from both pollen and honeydew because these non-prey food sources have a positive effect on the life history of the two predator species, especially E. scutalis.

Acari↗
PubMed2001

Early introduction of cereals into children's diets as a risk-factor for grass pollen asthma.

BACKGROUND: The prevalence of asthma has increased from the 1950s to the 1990s. The relationship between diet and asthma is an area of controversy that has never been fully evaluated. Attempts at dietary prevention of asthma have produced conflicting results. We have recently identified allergens from cereals that show cross-reactivity with proteins in grass pollen. An early intake of cereals in the diet during early life might cause IgE sensitization to cereals. It is not known whether such sensitization predisposes the development of allergy to pollen. METHODS: To test this hypothesis, a cross-sectional study and an observational case-control analysis of reviewed data were carried out on 16381 patients who had been admitted to our Allergy Unit between 1989 and 1999. All the patients underwent allergy tests to identify asthma risk-factors. All information in our data base was analysed using the SPSS computer system. RESULTS: There has been an increase of 7.8% in incidences of allergic asthma and a 7.3% increase in asthma due to grass pollen in the last decade. Grass-pollen asthma was associated with sensitization to cereals. The early introduction of cereals in the diet of children was found to be a risk factor for grass-pollen asthma (OR = 5.95; 95% CI 3.89-9.10). CONCLUSIONS: These findings document the progression of allergic asthma during a decade in a large sample of people who were influenced by similar environmental conditions and studied with the same diagnostic methods. This study represents the largest database of patients in which a common food is shown to be a risk factor for asthma.

Adult↗
PubMed2004

Reproduction mode in the allopolyploid facultatively apomictic hawkweed Hieracium rubrum (Asteraceae, H. subgen. Pilosella).

The versatility of the breeding system in the hybridogenous hexaploid, Hieracium rubrum, was demonstrated in emasculation and crossing experiments. The flow-cytometric ploidy analysis of 1095 seedlings amongst its' progeny enabled the determination and quantification of the reproductive pathway (apospory, haploid parthenogenesis, cross-fertilization of both reduced and unreduced female gametes) responsible for each progeny class. The progeny profiles were stable between two successive years. The percentage of hybrids arisen from crosses with tetraploid sexual H. pilosella was 7.9%. The rate of trihaploids generated by H. rubrum when crossed to H. pilosella was 3.95%, similar to that of pentaploid (n + n) and octoploid (2n + n) hybrids (3.95% and 3.39%). Unreduced pollen from H. pilosella contributed to hybridization much less frequently (0.56% of all progeny), than unreduced eggs of H. rubrum. The increased frequency of trihaploids formed by crossed compared to emasculated plants suggests an interaction between the presence of pollen and the autonomous development of meiotic embryo sacs. Although the environmental conditions (garden compared to unheated glasshouse) influenced the progeny following the emasculation, no corresponding response to environment was detected amongst the autonomously derived progeny following pollination with H. pilosella. However, there was an influence of pollen parent on progeny which varied under the different environmental treatments. The importance of residual sexuality in reproduction of apomicts is evident. The non-maternal progeny was generated with highly variable frequency especially in the glasshouse, with some capitula reaching up to 50%. Having an autonomous endosperm development, Hieracium subgen. Pilosella is almost unique among other aposporous genera, in which such variable reproduction mode is connected with pseudogamy.

Asteraceae↗
PubMed2002

Long-term efficacy of preseasonal grass pollen immunotherapy in children.

BACKGROUND: In a previous controlled study we demonstrated that preseasonal grass pollen immunotherapy for three years was effective in children. In the current study we examined the same group of patients to see if there is still a benefit six years after discontinuation of treatment. METHODS: Thirteen of 14 patients with previous specific immunotherapy (SIT) and 10 out of 14 patients of the control group were prospectively followed during the grass pollen season. Outcome measures were seasonal symptom scores for eyes, nose and chest, the use of symptomatic medication and visual analog scale. Objective measures included skin prick test reactivity to seasonal and perennial allergens and conjunctival provocation testing. RESULTS: During the 13 week observation time scores for overall hayfever symptoms (P < 0.004) and individual symptoms for eyes (P < 0.02), nose (P < 0.04) and chest (P < 0.01) as well as combined symptom and medication scores (P < 0.002) remained lower in the group with previous SIT. Only 23% of patients with previous pollen-asthma who had received SIT experienced pollen-associated lower respiratory tract symptoms compared to 70% in the control group (P < 0.05). There was no significant difference in the use of pharmacological treatment during the pollen season except for asthma medication. The average visual analog scale was lower in the post-SIT group (P < 0.05). Six years after cessation of SIT the immediate skin response to grass pollen remained decreased compared to the reaction of the controls (P < 0.01). There was also a tendency for higher allergen concentration to provoke a conjunctival response in the post-SIT group but without reaching statistical significance. Eight years after commencement of SIT, 61% of the initially pollen-monosensitized children had developed new sensitization to perennial allergens compared to 100% in the control group (P < 0.05). CONCLUSIONS: There is still a significant clinical benefit six years after discontinuation of preseasonal grass pollen immunotherapy in childhood. SIT in children with pollen-allergy reduces onset of new sensitization and therefore has the potential to modify the natural course of allergic disease.

Adolescent↗
PubMed1987

An enzyme-linked immunosorbent assay (ELISA) for in vitro pollen growth based on binding of a monoclonal antibody to the pollen tube surface.

An indirect method of quantifying in vitro pollen growth has been developed. This is based on the finding that a monoclonal antibody (PCBC3), which has a primary specificity for alpha-l-arabinofuranosyl residues, binds to the surface of in vitro grown pollen tubes of the ornamental tobacco, Nicotiana alata. This binding was quantified using an enzyme linked immunosorbent assay (ELISA). The method was used to determine the effects of 2-deoxy-d-glucose and nonanoic acid on in vitro pollen growth.

Journal Article↗
PubMed2006

Prediction of airborne Alnus pollen concentration by using ARIMA models.

To take preventative measures to protect allergic people from the severity of the pollen season, one of aerobiology's objectives is to develop statistical models enabling the short- and long-term prediction of atmospheric pollen concentrations. During recent years some attempts have been made to apply Time Series analysis, frequently used in biomedical studies and atmospheric contamination to pollen series. The aim of this study is to understand the behaviour of atmospheric alder pollen concentrations in northwest Spain in order to develop predictive models of pollen concentrations by using Time Series analysis. The prediction line proposed for Oviedo and Ponferrada are similar (Arima 2,0,1) while in Vigo a more accurate model founded by Arima (3,0,1) and in Leon (1,0,1) was used. The results suggest that Ponferrada and Oviedo are the cities in northwest Spain where Alnus pollen allergic individuals should to take preventive measures to protect themselves from the severity of the pollen season. Alnus pollen values higher than 30 grains/m3, a quantity considered sufficient to trigger severe allergy symptoms of other trees of the Betulaceae family, could be reached during 25 days in some years. The predicted lines conformed with the observed values overall in the case of Leon and Ponferrada. Time Series regression models are especially suitable in allergology for evaluating short-term effects of time-varying pollen appearance in the atmosphere.

Air Pollution↗
PubMedDate not supplied

[The demonstration of environmental radioactive contamination by its gametocidal action].

Two Viola matutina Klok. populations growing in two areas of the thirty-kilometer zone of Chernobyl varying in gamma radiation background have been studied. Stable, repeated (during a period of 1987-1988) differences between the populations with respect to the amount of sterile pollen and the pattern of anther distribution curves have been revealed. It is suggested that the increased radiation loading is the cause of the increased occurrence of sterile pollen in one of the populations.

Accidents↗
PubMed2003

Bet v 1, the major birch pollen allergen, initiates sensitization to Api g 1, the major allergen in celery: evidence at the T cell level.

Due to IgE cross-reactivity, birch pollen-allergic individuals frequently develop type I hypersensitivity reactions to celery tuber. We evaluated the T cell response to the major allergen in celeriac, Api g 1, and the cellular cross-reactivity with its homologous major allergen in birch pollen, Bet v 1. Api g 1-specific T cell lines (TCL) and clones (TCC) were established from peripheral blood mononuclear cells of allergic patients. Epitope mapping of Api g 1 with overlapping Api g 1-derived peptides revealed one dominant T cell-activating region, Api g 1(109-126). TCL and TCC generated with Api g 1 cross-reacted with the birch pollen allergen and, although initially stimulated with the food allergen, cellular responses to Bet v 1 were stronger than to Api g 1. Epitope mapping with Bet v 1-derived peptides revealed that T cells specific for several distinct epitopes distributed over the complete Bet v 1 molecule could be activated by Api g 1. Bet v 1(109-126) was identified as the most important T cell epitope for cross-reactivity with Api g 1. This epitope shares 72% amino acid sequence similarity with the major T cell-activating region of the food allergen, Api g 1(109-126). Our data provide evidence that humoral as well as cellular reactivity to the major celery allergen is predominantly based on cross-reactivity with the major birch pollen allergen. The activation of Bet v 1-specific Th2 cells by Api g 1, in particular outside the pollen season, may have consequences for birch pollen-allergic individuals.

Allergens↗
PubMed1994

[Effect of bee pollen on maternal nutrition and fetal growth].

Plant pollen collected by the honeybee is called bee pollen, which is a natural nutrient. We studied the effects of the bee pollen of Brassia campestres L. on maternal nutrition and fetal growth. Pregnant Sprague-Dawley rats at O-d were divided randomly into three groups. The control group (C) was fed with a diet. The other two groups (A) and (B) were fed with the diet plus bee pollen 20 g/kg.d-1 and 10 g/kg.d-1, respectively. All the dams in each group took a diet and drank water and libitm. Pollen-fed dams in both groups (A) and (B) had greater body weight and higher levels of haemoglobin, total protein, serum iron and albumin (P < 0.01, P < 0.05). Fetuses of pollen-fed dams had greater body weight (P < 0.01) and lower death rate (P < 0.005). No gross external, visceral and skeletal malformations were observed in the fetuses. These results suggested that bee pollen could improve maternal nutrition without affecting normal fetal development. It is a practical and effective nutrient during pregnancy.

Animal Nutritional Physiological Phenomena↗
PubMed1989

Bronchial challenge responses in asthmatic patients sensitized to Artemisia spp. pollen.

To characterize the patients whose asthma may be caused by Artemisia pollen extracts, we studied the bronchoprovocation test with Korean Artemisia pollen extracts (1:20 w/v), methacholine bronchial challenge test and wormwood-RAST in 32 asthmatic patients sensitized to Artemisia pollen. Twenty-six(81%) developed a 15% or greater decrease in FEVI after the inhalation of Artemisia pollen extracts and 13 patients showed early responses, 8 dual, and 5 late only. Thirteen(50%) out of 26 positive responders complained of seasonal aggravation of their asthmatic symptoms. Seven(53.8%) of the 13 seasonal type patients, 10(76.9%) of the 13 perennial type and 5(100%) of the 5 negative responders showed concurrent positive responses in the house dust bronchoprovocation test. The bronchial responsiveness to allergen(PD15) was more dependent upon the specific IgE level(bound radioactivity on wormwood-RAST) and multiple regression analysis revealed that the specific IgE level and methacholine PC20 may be contributory to allergen PD15. These results suggested that specific IgE to Artemisia pollen appears to be the major contributor to susceptibility to Artemisia bronchial challenges and this pollen may be considered as one of the important allergenic etiologies of atopic asthma in this country.

Allergens↗
PubMed2005

Effects of simulated acid rain on fertility of litchi.

The regulatory role of calcium in fertility of pollen and pistil under simulated acid rain was investigated. The germination percentage of pollen treated with acid rain of pH 4.5 was 9.42% lower than that of control, and that of pH 3.5, pH 2.5 and pH 1.5 were 22.47%, 45.49% and 71.62%, respectively. Simultaneously, the injury character of pollen was obviously observed when flowers were treated with acid rain of pH 3.5. The difference in fruit setting rate between the female flower treated with acid rain of pH 4.0 and the control was significant at p < 0.05. Ca(NO3)2 of 0.2-0.4 mmol/L could promote pollen germination under the stress of acid rain. The beneficial function was reduced when calcium concentration surpassed 0.8 mmol/L. Spraying 2 mmol/L Ca(NO3)2 reduced the injury of acid rain to pistil and increased fruit-setting rate significantly. The physiological importance of calcium during pollen germination and pistil development was also discussed.

Acid Rain↗
PubMed2002

Conifer reproductive development involves B-type MADS-box genes with distinct and different activities in male organ primordia.

The Norway spruce MADS-box genes DAL11, DAL12 and DAL13 are phylogenetically related to the angiosperm B-function MADS-box genes: genes that act together with A-function genes in specifying petal identity and with C-function genes in specifying stamen identity to floral organs. In this report we present evidence to suggest that the B-gene function in the specification of identity of the pollen-bearing organs has been conserved between conifers and angiosperms. Expression of DAL11 or DAL12 in transgenic Arabidopsis causes phenotypic changes which partly resemble those caused by ectopic expression of the endogenous B-genes. In similar experiments, flowers of Arabidopsis plants expressing DAL13 showed a different homeotic change in that they formed ectopic anthers in whorls one, two or four. We also demonstrate the capacity of the spruce gene products to form homodimers, and that DAL11 and DAL13 may form heterodimers with each other and with the Arabidopsis B-protein AP3, but not with PI, the second B-gene product in Arabidopsis. In situ hybridization experiments show that the conifer B-like genes are expressed specifically in developing pollen cones, but differ in both temporal and spatial distribution patterns. These results suggest that the B-function in conifers is dual and is separated into a meristem identity and an organ identity function, the latter function possibly being independent of an interaction with the C-function. Thus, even though an ancestral B-function may have acted in combination with C to specify micro- and megasporangia, the B-function has evolved differently in conifers and angiosperms.

Arabidopsis↗
PubMed1997

pH gradients are not associated with tip growth in pollen tubes of Lilium longiflorum.

The cytoplasmic pH of growing pollen tubes of Lilium longiflorum Thunb. was measured using the pH-sensitive fluorescent dye 2',7'-bis-(carboxyethyl)-5(6')-carboxyfl uorescein and confocal fluorescence ratio imaging. The average cytoplasmic pH in the clear zone of the pollen tube tip was pH 7.11, and no consistent pH gradients were detected in the clear zone, averaging around -1.00 milli pH unit microm(-1), or along the first 50 microm of the tube (3.62 milli pH units microm[-1]). In addition, no correlation was observed between the absolute tip cytoplasmic pH or the pH gradient and the pollen tube growth rates. Shifts of external pH to more acidic pH values (pH 4.5) caused a relatively small acidification by 0.18 pH units, whereas a more alkaline external pH >7.0 caused a dramatic increase in cytoplasmic pH and growth stopped immediately. Stimulation of the plasma membrane H+-ATPase by fusicoccin, resulted in an increase of tube growth but no change in cytoplasmic pH. On the other hand, vanadate (250-500 microM), a putative inhibitor of the pump, stopped tube growth and a slight cytoplasmic alkalinisation of 0.1 pH units was observed. Vanadate also arrested fusicoccin-stimulated growth and stimulated an increased alkalinisation of around 0.2 pH units. External application of CaCl2 (10 mM) caused a small acidification of less than 0.1 pH units in the clear zone, whilst LaCl3 (250 microM) caused slight and rather variable perturbations in cytoplasmic pH of no more than 0.1 pH units. Both treatments stopped growth. It was inferred from these data that tip-acid cytoplasmic pH gradients do not play a central role in the organisation or maintenance of pollen tube tip growth.

Calcium Chloride↗
PubMed1983

Asthma and increases in nonallergic bronchial responsiveness from seasonal pollen exposure.

Serial measurements of symptoms, peak flow rates, methacholine bronchial responsiveness, and ragweed-specific IgE antibodies were made before and during the ragweed pollen season in 13 sensitized subjects. Allergen inhalation tests were carried out with aerosols of pollen extract out of season in nine subjects; isolated early asthmatic responses were provoked in four, and dual responses (early followed by late) were provoked in five. During the pollen season all subjects developed hay fever and eight had symptoms of asthma. There was a real increase in methacholine responsiveness during the ragweed season. This increase appeared before or after the occurrence of asthma symptoms and changes in flow rates and was greater in subjects with symptoms in the pollen season, dual responses after allergen inhalation tests, and higher levels of ragweed-specific IgE antibodies. The results confirm the occurrence of seasonal asthma and increases in nonallergic (nonspecific) bronchial responsiveness to methacholine from seasonal pollen exposure. They suggest that the occurrence of symptoms is closely linked to the allergic inflammatory reaction and the induction of increased nonallergic responsiveness.

Adolescent↗
PubMed1989

The effect of preseasonal immunotherapy on the production of histamine-releasing factor (HRF) by mononuclear cells from patients with seasonal asthma: results of a double-blind, placebo-controlled, randomized study.

The effect of immunotherapy on the production of histamine-releasing factor (HRF) by mononuclear cells (MNC) from patients with seasonal asthma was investigated in a double-blind, placebo-controlled, randomized study. Twenty-four patients with asthma were randomly divided into a placebo-treated group and a grass pollen-treated group. In vitro production of HRF by MNCs and the provocative concentration of histamine that causes 20% fall in FEV1 were measured before and after immunotherapy, and symptoms were monitored during the pollen season. MNCs from the patients were either cultured alone, spontaneous HRF production (spHRF), or in the presence of grass allergens (grass-stimulated HRF production), and the supernatants were assayed for HRF activity with basophils from a single donor after the study. We found that MNCs from patients with seasonal asthma to grass pollen spontaneously produce substantial amounts of HRF. The group of patients treated with placebo developed typical symptoms in the pollen season and also an increase in HRF production. In contrast, patients treated with grass pollen demonstrated reduced symptoms and no increase in spHRF production. A high degree of correlation between spHRF productions and symptom scores in both treated groups was noted. After 2 years of immunotherapy, allergen-stimulated HRF production decreased significantly, whereas spHRF production decreased significantly only in the patients who were clinically benefitted. The change in the provocative concentration of histamine that causes 20% fall in FEV1 during the pollen season highly correlated with the change in HRF production. The results of this study suggest that HRF might be involved in the pathogenesis of atopic asthma.

Adult↗
PubMed2006

[Cytological and embryological observation on the cross of autotriploid x diploid in rice].

In this report, the process of hybridization between different ploidy levels was observed in rice. Autotriploid (2n = 36) 149-B, generated naturally from the twin-seedling rice population SAR-2, was used as the female parent crossing with a normal diploid variety Shuhui 363. The processes of fertilization and embryological development were investigated. The pollen could germinate in triploid tissue of pistil normally and arrive at micropyle. But the percentage of double fertilization was only 8.89%, and the percentage of seed setting was 0.566%. The hybridization obstacles mainly occurred in the process of fertilization. Barriers of double fertilization, prolongation and abnormal development of proembryo, and even development stopping or differentiation failure of embryo and/or endosperm could result in abnormal development and abortion of zygote.

Diploidy↗