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PubMed1999

Pollen-stigma adhesion in Arabidopsis: a species-specific interaction mediated by lipophilic molecules in the pollen exine.

To investigate the nature and role of cell adhesion in plants, we analyzed the initial step of pollination in Arabidopsis: the binding of pollen grains to female stigma cells. Here we show this interaction occurs within seconds of pollination. Because it takes place prior to pollen hydration, it also requires adhesion molecules that can act in a virtually dry environment. We developed assays that monitored adhesion of populations of pollen grains and individual cells. Adhesion between pollen and stigma cells is highly selective - Arabidopsis pollen binds with high affinity to Arabidopsis stigmas, while pollen from other species fails to adhere. Initial binding is independent of the extracellular pollen coat (tryphine), indicating that adhesion molecules reside elsewhere on the pollen surface, most likely within the exine walls. Immediately after pollination, the stigma surface becomes altered at the interface, acquiring a pattern that interlocks with the exine; this pattern is evident only with pollen from Arabidopsis and its close relatives. Purified exine fragments bind to stigma cells, and biochemical analyses indicate that this specific, rapid and anhydrous adhesion event is mediated by lipophilic interactions.

Arabidopsis↗

PubMed1986

Pollen-stigma interactions in Brassica. IV. Structural reorganization in the pollen grains during hydration.

With the aid of osmium tetroxide vapour, dry pollen and pollen at various stages of hydration has been fixed anhydrously for examination with the transmission electron microscope (TEM). In addition to establishing features characteristic of grains at different states of hydration, this technique has enabled the detection of a superficial layer investing both the exine and the pollen coating. This layer, some 10 nm in depth, binds both lanthanum and Alcian Blue and is shown to be the first component of the pollen grain to make contact with the stigmatic pellicle. The use of vapour fixation has also rendered it possible to chart the passage of water into the pollen grains with great accuracy, for each level of hydration displays a strikingly different cytoplasmic organization. For example, dry pollen is characterized by the presence of unusual structures at the protoplast surface and large numbers of spherical fibrillar bodies, whilst the protoplast of hydrating pollen is conspicuously stratified and contains a peripheral layer of membranous cisternae, subjacent to which is a fibrillar matrix derived from the spherical bodies found in the dry grains. Vapour-fixed, fully hydrated pollen resembles conventionally fixed grains. The pollen coating appears electron-translucent after anhydrous fixation and contains discrete, slightly rounded bodies some 50 nm in diameter. The uptake of water by grains on the stigma is accompanied by conspicuous structural changes in this layer for, after a short period in contact with the papillar surface, the spherical bodies rapidly disappear and the coat becomes electron-opaque. Close examination of this 'converted' coating reveals the presence of membranous vesicles and other structural components.

Brassica↗

PubMed1993

[Birch pollen nasal allergy in Sapporo and its cross reactivity with alder pollen].

We reported here 53 cases of birch pollen nasal allergy treated in our department from 1990 to 1991. The 53 patients constituted 16% of 335 total nasal allergy patients. In recent years, the number of birch pollen nasal allergy patients has apparently been gradually increasing in Sapporo. Skin tests, radioallergosorbent test (RAST) determinations and nasal provocation tests were performed for the diagnosis of birch pollen nasal allergy, and high degrees of correlation were observed among these tests. Therefore, it seems to be reasonable to determine the birch pollen allergy with only a positive case history of early springtime hay fever and RAST determination. A high correlation coefficient (Rho) value was found with RAST determinations between birch pollen and alder pollen. Furthermore, RAST of alder pollen was significantly inhibited by birch pollen extracts. These results indicate cross reactivity, presumably due to partial immunologic identity between these two pollen allergens.

Adolescent↗

PubMed2004

[Juniper pollen monitoring by Burkard sampler in Galveston, Texas, USA and Japanese cedar pollen counting in Fukuoka, Japan -- introduction of Pan American Aerobiology Association protocol counting technique].

We have monitored Juniper pollen which caused winter allergy symptoms by Burkard sampler in Galveston, Texas. We identified and counted Juniper pollen grains by PAAA protocol which was a comprehensive guideline for the operation of Hirst-Type suction bioaerosol sampler, (original of Burkard sampler) in the USA. In Galveston we were able to detect the Mountain Cedar (Juniperus ashei) pollen from December to of January, and Eastern Red Cedar (Juniperus virginiana) which has cross reactivity to MC from almost middle of January to February. There is no MC vegetation in Galveston. We found the pollen grains were transported from west at Edward Plateau in West Texas where it was thickly wooded. Then, we tried to monitor Japanese Cedar (JC) pollen grains in Fukuoka, Japan according with the same method. We found the significant positive correlation between the pollen counts using one single longitudinal traverse counting technique in the PAAA protocol and the JC pollen counting on the whole of Melinex tape per 24 hours (R2=0.9212, p=0.0001), and the gravitational method that is Durham sampler's pollen counting in 2002 (R2=0.489, p=0.0001), and in 2003 (R2=0.948, p=0.0001) respectively. We suggested that we can use the PAAA protocol for airborne pollen investigation in Japan by Burkard sampler.

Air Pollution↗

PubMed1989

[Hourly variations in the dispersion of Japanese cedar (Cryptomeria japonica) pollens in the Yamagata basin and the effect of cold and warm fronts on the pollen counts].

Airborne pollen counts of Cryptomeria japonica (CJ) were investigated at three points in the Yamagata Basin: 1. the central part of Yamagata City (point A), 2. at the foot of a mountain with a CJ grove (point B), 3. within the CJ grove (point C). At the beginning of the CJ pollen season, the airborne pollen counts at point B showed higher values than those at point A, whereas the relation of the count values was reversed later at the major pollen dispersion period. Numerous airborne pollens were detected at point C during the daytime, but few at night. On the other hand, many airborne pollens were found at point A during both the day and night. These results suggest that the pollens which come to rest on the roofs of houses and the pavement surfaces may be blown up into the air again. It was found that many pollens could be counted before a warm front passed through point A but that few pollens could be counted at the passage of a cold front.

Air↗

PubMed1989

[Experiences with desensitization of early spring pollen allergy using 2 tree pollen extracts].

Forty patients with tree pollen-induced allergy (rhinitis, conjunctivitis or combination from both with asthma) were hyposensitized with an extract from isolated birch pollen or a pollen mixture (hazel-, alder-, oak- and hornbeam pollen). The distribution of the different extracts was random. After 3-year treatment, no statistical differences were found between the two groups, especially regarding clinical effectiveness, duration of symptoms or symptom score. In conclusion, we recommend a hyposensitization with birch pollen extract in tree pollen-induced allergy. If evidence is present of sensitization against other tree pollens, especially hazel or alder, or in cases without therapeutic effect after two years of hyposensitization with birch pollen, an attempt with a tree pollen mixture extract is indicated.

Adult↗

PubMed1979

[Pollionosis: I. Findings on the clinical aspects and the pollen spectrum in 1565 pollen-sensitive patients].

Case histories are analyzed of 1565 hay fever patients first attending an allergy unit. The mean age of the test persons was 19.5 years. 40% were in the age group 5 to 15 years. The sex distribution showed a slight but statistically significant prevalence of males (56.6%). 56.8% had a positive family history of allergies and 44.2% had other allergic conditions such as atopic dermatitis (31.6%), perennial rhinitis and perennial asthma (19% each), urticaria, food allergy and drug allergy (5% each) and insect sting allergy (3%). A clear cut peak both for rhinitis and for asthmatic symptoms %30.5% and 20.2% respectively) was found in the age group 5--9 years. Up to the 14th year the symptoms of pollen allergy were already exhibited by 68.5% of the patients. 97% of the pollen allergics suffered from rhinitis, 95% from conjunctivitis, 40% from bronchial asthma and another 20% from tracheobronchitis or asthmatic bronchitis. As additional symptoms of pollen allergy due to haematogenous spread of the pollen antigens we observed a seasonal form of atopic dermatitis in 3%, a seasonal urticaria or angioedema in 3.5%, migraine in 6.3% and arthralgia, gastro-intestinal troubles and fever in fewer than 1% each. Almost 98% of the patients were sensitized to grass or cereal pollens. However, only 18% suffered from an isolated grass pollinosis (summer hay fever). The other patients were additionally clinically sensitized by other pollens with different blossoming periods, i.e. 35% by three pollens responsible for the so-called spring pollinosis, and 50% by weeds (plantain, nettle, mugwort) the cause of late summer pollinosis. Only 13 patients suffered from an isolated spring pollinosis (hazel, alder, birch, willow). In 14 patients (not quite 1%) with a clear-cut history and clinical symptoms of pollinosis, all the skin tests were negative. In these cases the sensitization was probably restricted to the respiratory tract. Despite the new in-vitro methods such as the RAST, carefully performed skin tests linked to a knowledge of the pollen calendars of the region and the allergological history remain the most reliable and cheapest procedure for the specific diagnosis of pollen allergy.

Adolescent↗

PubMed1982

Cytochemical localization of some hydrolases in the pollen and pollen tubes of Amaryllis vittata Ait.

Some hydrolases are localized cytochemically in the pollen and pollen tubes of Amaryllis vittata Ait. The function of different enzymes is discussed in relation to pollen tubes morphogenesis. Activity of most of the enzymes was confined to colpus region, pollen wall and general cytoplasm of pollen and pollen tube. The activity of hydrolytic enzymes like acid monophosphoesterase and lipase and was nil in the exine of both germinated and ungerminated pollen, whereas intense reaction for esterase was observed in exine. Enzyme activity increased after germination which suggest the hydrolysis of stored metabolites and synthesis of proteins and other metabolites for the active growth of pollen tube. Intense reaction for enzymes like alkaline phosphomonoesterase, ATP-ase, 5-nucleotidase etc. at the tip region of pollen tube suggest their role in physiological processes associated with exchange of materials through intercellular transport during tube wall polysaccharide biogenesis.

5'-Nucleotidase↗

PubMed1997

[Marked increase of atmospheric pollen dispersion of ragweed (Ambrosia spp.)--annual changes in atmospheric pollen counts of major allergen plants in autumn in Saitama Prefecture].

An annual atmospheric pollen survey was performed for 14 consecutive years in the autumn at Sakado city, Saitama prefecture. The survey was performed on the transition of pollen dispersion of major allergen plants: ragweed (Ambrosia spp.), Humulus japonicus, Artemisia spp. and Gramineae. 1. Annual total pollen count of ragweed showed marked increases beginning from 1991. Total pollen count in 1991 was 8.8 times and that in 1996 was 18.6 times that in 1983. This increase is probably caused by marked proliferation of giant ragweed which is left without mowing as it is on a dry riverbed, and consequently produces much more pollen than short ragweed. 2. Annual increases in total pollen counts of other major plants which disperse their pollen in the same season as ragweed were 0.95 times in 1991 and 0.5 times in 1996 that in 1983 for Humulus japonicus, 0.68 times in 1991 and 1.5 times in 1996 that in 1983 for Artemisia spp. and 1.3 times in 1991 and 1.4 times in 1996 that in 1983 for Gramineae. None of these species showed a marked increase of pollen dispersion although they showed some annual variation. The above findings suggest that changes in the proliferous state of various allergenic plants due to environmental change should be considered with respect to characteristics of pollen allergy.

Air Pollution↗

PubMed1998

A study of pollen prevalence in relation to pollen allergy in Malaysian asthmatics.

In this paper we report results of skin prick tests (SPT) using pollen extracts on 200 patients with clinical symptoms of asthma, and results of a parallel study in which pollen was collected and classified over a period of 18 months. The patients were outpatients from the University Hospital in Kuala Lumpur, Malaysia, while the pollen grains were collected with a spore trap placed in the campus of the University of Malaya, approximately one kilometer from the University Hospital. Pollen extracts of 3 grasses (Bahia, Bermuda, rough pigweed) and 2 flowering trees, Acacia and Melaleuca, were used in the SPT. Of the 29.5% asthmatics with positive SPT reactions, 21.5% were to one or more of the grass pollens, 21.5% to Acacia and 7.5% to Melaleuca pollen. Acacia and Bermuda grass extracts were the most allergenic, which agreed with results of the pollen collection which showed grass and Acacia pollen grains to be the two most commonly found pollens.

Acacia↗

PubMed1978

[Development of allergic reactivity to Artemesia pollen during combined sensitization to pollen and microbes].

Some regularities of formation of hypersensitivity of the immediate type to the pollen of Artemisia absinthium were studied under conditions of combined hypersensitivity to pollen and Brucella abortus 19-BA vaccine strain; the latter was administered 3, 12, and 28 days after the pollen. The degree of specific allergic reconstruction to the pollen was studied by passive skin anaphylaxis after Ovary, indirect degranulation of mast cells of healthy rats, and by general anaphylaxis in response to intravenous injection of the Artemisia absinthium pollen water-salt extract. Early formation of allergy to the pollen was observed in the groups of animals with combined hypersensitivity to the pollen and brucellae. The degree of allergic reactivity to the pollen allergen was more expressed in the groups with combined allergy than in those with pure pollen hypersensitivity at all the stages of this experiment.

Anaphylaxis↗

PubMed1976