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Biomedical subjects

A Shomer-Ilan

Publications and source records attributed to A Shomer-Ilan.

11 recordsLinked to original sources
PubMed1997

Allergenicity of the pollen of Pistacia.

Differences in IgE binding and skin responses to pollen extracts of four species of Pistacia, and some immunochemical characteristics of this pollen were investigated. The incidence of positive SPT among atopic patients varied between 31.5% to the pollen extracts of P. vera and 24.6% to P. palaestina. The antigens are located on the exine of the grains as well as in their cytoplasm. Some of the antigens are common to all four species, whereas others seem to be specific. Cross-reactivity was found among the four species of Pistacia and between them and Schinus terebintifolious. Five conspicuous IgE-binding bands were observed in the immunoblots of the four examined species, the bands of 49, 57, 64, 68, and 79 kDa. The 36-37-kDa band of P. lentiscus and the 60- and 84-kDa bands of P. atlantica and P. vera were also noticeable. As the flowering seasons of Pistacia and Schinus do not overlap, the patients are exposed to such pollen for more than 4 months a year. Apparently, Pistacia pollen is a major source of allergy.

Binding Sites, Antibody↗
PubMed1991

[Artemisia monosperma of the coastal plain as an allergen source in Jerusalem].

The possibility that pollen grains of Artemisia monosperma (AM) are transported to Jerusalem from their native habitat along the coastal plain was investigated. Air-borne pollen grains were sampled in the early autumn of 1989 with a Rotorod pollen sampler. During that period only 1 of the 4 species of AM in Israel, A. monosperma, was flowering. The sampling day was typical for the late summer, with a light NW breeze. Sampling was done simultaneously in 3 sites: Tel Aviv, Carmei Yosef and Jerusalem. The greatest concentration of pollen in Tel Aviv was found during the morning hours and decreased during the course of the day. Pollen counts in Carmei Yosef reached a maximum at 11:00 a.m. A substantial number of air-borne AM pollen was recorded in Jerusalem, with a daily peak at 1:00 p.m. Such results fit well the distribution pattern of the pollen as expected from the recorded wind velocity and direction. They also agree well with the data for transportation of other air pollutants from the coastal plain to Jerusalem. Apparently AM pollen is transported to Jerusalem over distances of many tens of kilometers, even on days with light winds. Therefore, such pollen may constitute an allergenic factor in Jerusalem in the autumn. It is reasonable to assume that transportation of pollens of other coastal plants follows a similar pattern.

Allergens↗
PubMed1989

[Sensitization to pollens in a changing environment: Israel].

Israel was originally a country with desert climate and extensive agriculture. During the last 40 years, due to artificial irrigation, a rich vegetation and intensive agriculture have developed. Hayfever prevalence has risen between 1952 and 1986 from an average of 0.3% to 6.3% (with a range from 4% in the urban to 15% in the rural communities). Considering that significant (P less than 0.001) impact of pollen quantity upon hayfever incidence, an elementary pollen information system was organized (as described in the article) to help both allergists and allergic patients in their joint effort to avoid the harmful effect of a changing environment.

Agriculture↗
PubMed1989

Forecasting pollen pollution: correlation with floral development.

Variations in the time course of flowering and in its intensity were recorded for regions in Israel along with variable climatic conditions. Such variations had an effect on pollen release into the air and on pollen counts. Two approaches for forecasting allergenic pollen dispersion were compared: (1) a survey of floral development and flowering intensity and (2) a survey of airborne pollen. There was a positive correlation between the survey of flowering and airborne pollen counts, although pollen was occasionally found after the flowering season. Further, it predicted fairly accurately the beginning of the flowering time of each species in each regio, the expected flowering duration, and intensity. Conducting a survey of flowering is a simple, easy and inexpensive operation. It is highly recommended for regions with variable climates.

Air Pollution↗
PubMed1987

Positive skin tests to pollen extracts of four species of Pistacia in Israel.

Fifty-eight atopic and nine non-atopic volunteers, all residents of the Tel Aviv metropolitan area, Israel, were skin tested with extracts made from filtered pollen of Pistacia atlantica, P. lentiscus, P. palaestina and P. vera. Twenty-four out of the fifty-eight patients examined (41.4%) had positive skin reactions to at least one of the four examined species of Pistacia: seven of the patients reacted to all the examined extracts, whereas the other seventeen reacted to only some of them. Fifteen patients reacted to extracts of P. atlantica, sixteen patients reacted to extracts of P. lentiscus, ten patients reacted to extracts of P. palaestina and seven patients reacted to extracts of pollen of P. vera. None of the healthy, non-atopic volunteers reacted to any of the extracts. To the best of our knowledge, this is the first report of immunological reactions to pollen extracts of the genus Pistacia.

Humans↗
PubMed1987

Positive skin tests to fern spore extracts in atopic patients.

Thirty-six atopic and eight non-atopic adult volunteers who had been exposed to ferns in their homes, were skin tested with extracts obtained from seven species of house ferns. Out of the 36 atopic patients, 18 had positive skin reactions to at least one out of seven species of the most common house ferns, whereas none of the non-atopic, healthy controls had positive reactions to any of the ferns.

Humans↗
PubMed1981

Metabolism of sulfur compounds by whole filaments and heterocysts of Anabaena variabilis.

Filaments of the heterocyst-forming cyanobacterium Anabaena variabilis reproduced 35SO4(2)-, incorporating 35S into cysteine, methionine, glutathione, sulfolipid, and several unidentified metabolites. The majority of the incorporated label accumulated in reduced glutathione. Heterocysts isolated from labeled filaments contained the same major labeled products. Isolated, metabolically active heterocysts were unable to reduce 35SO4(2)-, but were able to incorporate 35S2- into cysteine and glutathione. The results suggest that the initial activation of SO4(2)- occurs in vegetative cells and that some reduced forms, possibly including S20, are translocated into heterocysts.

Cyanobacteria↗
PubMed1979

Effect of water regime on carbon isotope composition of lichens.

delta(13)C values of the lichens Ramalina duriaei and Teloschistes villosus collected in their natural habitat were repeatedly measured during 2 years. Results show variations in the stable carbon isotope ratios ((13)C/(12)C). Such variations are correlated to the seasonal rainfall, i.e. low values of delta(13)C of the lichens during the winter and high values of delta(13)C during the dry summer. Relatively low delta(13)C values were obtained also in laboratory experiments with lichens grown under controlled humid conditions and in lichens collected from humid habitats.The variations in carbon isotopes were associated with quantitative metabolic changes. Under humid conditions an increase was obtained in the total amount of the extracted water-soluble fraction of the plant tissues as well as in the relative content of soluble carbohydrates.Analysis of the possible factors which may cause such variations indicates that the quantity of precipitation and the exposure time to high humidity were the main environmental factors causing seasonal variations in the delta(13)C values of the lichens. Such variations are dependent mainly on enzymic reactions and are probably less influenced by purely physicochemical processes. In view of the data presented here the balance between carboxylation and decarboxylation reactions seems to be the major factor for the observed seasonal differences. Winter accumulation of (12)C enriched components causes an over-all decrease in delta(13)C. During the summer, those storage materials are respired with concomitant increase in the delta(13)C of the residual plant material.

Journal Article↗
PubMed1979

Biochemical Specialization of Photosynthetic Cell Layers and Carbon Flow Paths in Suaeda monoica.

Suaeda monoica Frossk. ex J. F. Gmel is a C(4) plant with three different photosynthesizing cell layers. The outer chlorenchymatous layer shows a high activity of phosphoenolpyruvate (PEP) carboxylase but none of ribulose bisphosphate (RuBP) carboxylase. The electrophoretic protein band of RuBP carboxylase was missing in this layer. The second chlorenchymatous cells layer shows a very high activity of RuBP carboxylase and NAD malic enzyme and only traces of activity of PEP carboxylase. The third photosynthesizing cell type is comprised of the water tissue. It has moderate activities of RuBP carboxylase and PEP carboxylase. A model for carbon flow in Suaeda monoica leaves is proposed.

Journal Article↗
PubMed1975

Suaeda monoica, a C(4) Plant without Typical Bundle Sheaths.

Suaeda monoica Forssk. ex J. F. Gmel was found to possess the C(4) pathway of photosynthesis. The succulent leaves of Suaeda lack a green bundle sheath formation but have a layer of chlorenchyma, containing large and centripetally arranged chloroplasts, which surrounds the water tissue. We suggest that the proximity of a chlorenchymatous cell layer to the vascular bundles is not necessary for the operation of the C(4) pathway.

Journal Article↗