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Objective: Many research papers have addressed the beneficial qualities of forests in promoting mental and physical health. However, we should also be clear that forest environments could have detrimental effects. Some of them, which are of allergic nature, have hitherto been largely neglected., Methods: A comprehensive literature search has allowed us to achieve an initial synthesis on this matter. The emphasis was on temperate forests, especially on French forests., Results: Anemophilous pollen from deciduous trees is the major factor causing respiratory allergies in connection with forests. The risks are focused between mid-winter and late spring. Ash, hornbeam and birch pollen and, more incidentally, oak and beech pollen induce allergic reactions not only in the forests, but also at great distances. As a result of its high humidity and because decaying organic matter is very abundant, the forest environment presents also a breeding ground for mould growth. Accordingly, fungal spores can lead to allergic manifestations recalling pollinosis. Lastly, the "other" allergies mainly include contact dermatitis symptoms, which affect wood workers first and foremost. However, the pine processionary moth, whose zone of infestation is rapidly spreading northwards and whose setae contain several relevant allergens, represents one particular case., Conclusion: Allergic reactions observed in forests or originating in forests are sufficiently frequent to justify to set up a wide-reaching system for aerobiological and epidemiological monitoring.

Exposure to allergens could be either a risk factor of sensitization and nonspecific hyperresponsiveness in genetically predisposed patients or a risk of onset of asthma attack in certain allergic asthma. During the past 20 years, in western countries the houses have become higher and the number of furred pets have increased and have been more kept inside the house which makes probable that exposure to indoor aeroallergen has increased. The development of new methods of allergen measurements allows a more precise identification of allergen source and reservoirs, an assessment of allergen exposure and a monitoring of allergen eviction methods. Concerning mite allergens, controlled studies which showed a clinical efficacy are those with a global mite eviction and at least a 6 months follow-up for cat and dog allergens, high efficiency-filters air cleaners or vacuum-cleaners are able to reduce airborne cat or dog allergen levels. According to the increasing number of papers about allergen eviction, it seems logical to propose allergen eviction as "first line treatment" of allergic asthma. In the future, it would be interesting to develop biological markers to identify more accurately patients who have a clinical improvement after allergen eviction.

This paper shows by the means of clinic experiments how the regional pollinic calendar could help the day to day practice of allergology for the education of the allergic patient, the diagnosis, the therapeutic process and the pollinosis prevention.

Ragweed is the dominant type of the atmospheric spora of North America. In this paper we present a forecasting model based on the probabilistic distribution of pollen curves, which was applied to four years of sampling. Except for rapid (24 hours) but large fluctuations of the pollen concentration, our algorithm allows for an adequate estimate of the exposure risk. However, these rapid fluctuations can account for up to 40% of the annual pollen sum.

Abstract: Anaphylactoid reactions to iodine contrast media are rare but serious, possibly life-threatening and calling an appropriate and urgent care. The physiopathological mechanism of these reactions remains to be fully elucidated. This reaction is still mostly called “pseudoallergic” in the literature. However, recent papers emphasise that a true allergic process is more frequent than previously expected. They also insist on the interest of running allergy tests including skin testing. We report the case of an anaphylactic shock to iodine contrast media, occurring during coronary angiography. We performed an allergy check-up and found the culprit allergen. We also evidenced a cross-reaction to another contrast media from the similar group. On the other hand, there was no reaction to contrast media of other types. With these results, another coronary angiography could be performed without any adverse event. When hypersensitivity reactions to iodine contrast media occur, it is mandatory to perform a complete allergy check-up. This will help determine the precise mechanism of the reaction and find the culprit allergen. [Copyright &y& Elsevier]

Acrylates and methacrylates are industrial chemicals with insufficiently known irritating and allergic effects. After considering simples monoacrylates and monomethacrylates, this paper deals with the n-ethyleneglycol acrylates and methacrylates and some polyol polyacrylates and polymethacrylates. All of the diacrylates tested are irritants for humans at 3 p. 100 in olive oil but there is no irritation at 0,1 p. 100. Monomethacrylate and dimethacrylate are not irritants at 3 p. 100 in olive oil. Studies with animals confirm that diacrylates are more irritating than dimethacrylates and the Magnusson and Kligman method shows that the substances induce delayed hypersensitivity. Cross reactions were observed in homogeneous series (diacrylates or dimethacrylates) but not between series. These results are in good agreement with clinical observations. The irritating power of 5 polyacrylates and polymethacrylates of other polyols were tested in animals. For some of them, clinical observations indicate an allergic potential.

Acrylates and methacrylates are industrial chemicals with insufficiently known irritating and allergenic effects. In this paper, the simple monoacrylates and monomethacrylates are considered. Methyl acrylate is an irritant, giving a reaction in 10 out of 30 patients, when tested at 20 p. 100 in olive oil. It is also an allergen (2 out of 22 cases). Because of its irritating properties, the concentration of 2 p. 100 is proposed for allergeric investigations. Methyl methacrylate, at 20 p. 100 in olive oil, is not an irritant for humans, although we have observed a sensitization rate of about 15 p. 100 with an undiluted product. In animal studies (technic of Kligman and Magnusson), 10 p. 100 of the subjects reacted to a working concentration of 1 p. 100 in petrolatum (allergenicity degree II). A risk of sensitization due to test repetition exists, about 9 p. 100 and 15 p. 100 for methyl acrylate (20 p. 100) and undiluted methyl methacrylate, respectively. For the latter, sensitization appears around the 16 th-18th day and may be preceeded by an irritation (1 out of 3 cases). Allyl acrylate and allyl methacrylate are irritants which should be studied at a concentration of about 0,1 p. 100. A 5 p. 100 concentration in olive oil seems appropriate for studying allergies to the following monoacrylates and monomethacrylates: acrylamide and acrylonitrile, n-butyl, cyclohexyl, ethyl, ethyl-2-hexyl, ethoxy-2-ethyl, phenyl acrylates, cyclohexyl dodecyl, ethyl-2-hexyl, ethoxy-2-ethyl, methyl methacrylates.

Brucellin INRA is a new allergen used for the screening of brucellosis. It shows, by a delayed-type skin hypersensitivity reaction, the sensitization induced in animals by a brucella infection. The biological potency of each batch must be compared to that of a standard allergen. The use of guinea-pigs necessary for this quality control and the statistical analysis of the results are described and discussed. The aim of this paper is to provide the end-user with a simple and accurate method, and to alert him to the difficulties and limits of such a test.

This paper is concerned with the induction of experimental allergic asthma by active sensitization of the airways "vis-à-vis" heterologous protein. Thus in the rodent it is possible to sensitize the airways by direct intra-tracheal injection of the allergen without producing an allergic alveolitis; the concomitant injection of an adjuvant is however indispensable. Confirmation of the sensitized state can be made by in vitro measurements of isometric contraction of tracheal smooth muscle in the presence of the allergen. This active sensitization is accompanied by histocytological changes which are detected by immunomorphological techniques: the rise in the number of plasma cells sensitized to IgE in the mediastinal modes: the appearance (or increase in number) of intra-cytoplasmic IgE in the sub-epithelial tracheal mast cells and in certain non ciliated intra-epithelial cells, probably basophils, morphologically close to the mast cells.

Phadiatop is a new in vitro test used for screening patients with allergic respiratory diseases. This test, based on the RAST procedure, is performed with a paper disc to which a balanced mixture of relevant inhalant allergens has been coupled. One hundred and one adults ranging in age from 18 years to 73 years and 38 children (4 months to 15 years) were studied. We found a good correlation between this new test and total IgE (adults: 74.3 p. 100, children: 68.4 p. 100), specific IgE (adults: 91.1 p. 100, children: 100 p. 100) and skin test (adults: 79.2 p. 100, children: 97.1 p. 100). There was a high correlation between clinical atopy assessment and the result of Phadiatop, its efficiency was 83 p. 100 in adults and 97 p. 100 in children.

Abstract: The information provided by pollen counts cannot be ignored by allergists and allergic individuals, but the divergence sometimes observed with clinical observations has led the réseau national de la surveillance aérobiologique (RNSA) to initiate the monitoring network of allergens by immunosampling (Monalisa) project. Moreover, some recent papers has shown the influence of pollution in the region and even of the year on the content in pollen allergens, particularly that of birch pollen. Thus, the goal of the Monalisa project was to set up a measuring system based on an immunological method that would result in validation of this new way of measuring airborne pollen counts. This European Life Environment project includes nine partners: Bertin Technologies (France), RNSA (France), NPARU (England), UCO (Spain), UTU (Finland), UAM (Poland), UEVORA (Portugal), AIA (Italy), and Meteoswiss (Switzerland). The results obtained during the 2006 season and then in the 2007 campaign, after modifications made in the sampler, were not very good. The principal results concern the measurement of birch and olive allergens, captured essentially in the prepollination period and sometimes in the postpollination period. Detection of these allergens may be due either to their presence on submicroscopic particles emitted independently of pollination, these allergens cross-reacting with birch and olive allergens. The difficulties encountered in this study lead us to say that pollen counts, phenological observations and clinical data are still the best way to assess the effects of airborne pollen. [Copyright &y& Elsevier]

Abstract: The aim of this paper is to study the relation between climate change and the earliness of Birch pollination, a tree that produces allergenic pollen, which is of particular importance in north-western Europe. The study allowed us to make projections for the next few years in order to evaluate the evolution of Birch pollination starting date according to spring temperatures. It has been done in ten European locations, Kevo and Turku (Finland), London (United Kingdom), Paris and Lyon (France), Brussels (Belgium), Zürich (Switzerland), Vienna (Austria), Poznan and Cracow (Poland). The study period ranged from six to twenty-eight years depending on the city. Pollens were recorded daily thanks to volumetric Hirst traps, and the data were compared to monthly temperatures from January to May using correlations and multiple regressions. Except in Kevo where the trend is towards colder springs and a later pollination, in the other cities the results showed a spring warming associated with an earlier starting date of pollination: this trend is very well marked in Turku, Zürich, London, Vienna and Brussels, less evident in France while there is no trend in Poland. The results of this work should lead to an updating of the pollen calendars and the pollen forecast models, in the cities where there is a pronounced trend. [Copyright &y& Elsevier]

Abstract: Much attention is now being focused on foods from genetically modified plants because of the risk of allergenicity. No such risk has been reported for the first generation of GM plants made resistant to herbicides and insect larvae. Current experiments with hypoallergenic GM plants are reported and discussed in the present paper. The second generation of GM plants will improve the nutritional aspects of natural foods. Transgenic proteins could reach from 4 up to 8% of the total protein content in these foods. Any potential difference in allergenicity between second generation GM plants and the natural varieties must be examined with respect to the risk for food allergy caused by food products made from these plants and the risk for respiratory allergies in the people living near the crops caused by airborne pollen originating from the plants. WHO–FAO directives as well as the Codex Alimentarius proposals and the European Food Safety Authority (EFSA) guidelines recommend that transgenic proteins be screened for homology (by in silico study) and cross-reactivity with known allergens, as well as being examined carefully for modifications of host-plant proteomes. In vivo animal studies are also to be carried out to assess any potential immunogenicity. Lacking adequate safety data, the absence of potential allergenicity of transgenic plants cannot be ruled out. This is why data that do not meet the recommended safety criteria required for commercialization of GM plants do not allow us to rule out absolutely the risk that may be associated with products that are going to be commercialized. Therefore, it is essential that commercialized GM plants be monitored. We propose the establishment of public reference serum banks based on up-to-date WHO–FAO recommendations concerning the selection of sera according to precise criteria. We also propose establishing a system of allergovigilance linking national and European health and food safety agencies and a network of university hospital-based clinical and laboratory reference centres, together with a network of clinical allergists, responsible for the creation of the serum banks. Allergists working through these networks would be able to identify new sensitizations to transgenic foods in the population, just as they now identify new types of food allergies, which, in this case, would be GM foods. Such a project is now being established in France. [Copyright &y& Elsevier]

Abstract: Asthma morbidity and mortality have increased over the last ten years in most countries. In some countries now, it apears that asthma prevalence has reached a plateau. The increased prevalence, especially in children, should be explained by environnemental factors, since obviously our genes have not changed. In this paper, we will review the recent data concerning asthma prevalence, mortality, socio-economic impact and both environnemental and genetic risk factors. [Copyright &y& Elsevier]

In this paper, special consideration will be given to the following points:

The increase in asthma prevalence over the past 20 years could be due to modification of exposure to environmental factors (environmental theory) or to the lost of protective factors (hygienist theory). Among environmental factors this paper reviewed the controversial role of exposure to house dust mite (HDM). If exposure to HDM is deleterious in asthmatics known to be sensitised to this allergen, the effect of HDM exposure on asthma incidence has been challenged recently, based on longitudinal studies showing no correlation between level of exposure to HDM and asthma incidence. Exposure to animal dander may have protective effects. This review has shown that, even if some studies have shown potential protective effect of early exposure, the protection seems to be better in families with a low risk of atopy; almost all studies tend to show a deleterious effect of current exposure; exposure to dog dander may be more protective than cat. These studies cannot give definite conclusions to change current advices of early eviction of HDM and animal dander, especially in families with a high risk of atopy. The deleterious effect of passive smoking on asthma prevalence and severity is undisputable and our efforts should concentrate on obtaining effective eviction of passive smoking. [Copyright &y& Elsevier]