Biomedical subjects
Publications and source records attributed to F T Spieksma.
In a time-series study in The Netherlands, we found a strong association between the day-to-day variation in pollen concentrations and that of deaths due to cardiovascular disease, chronic obstructive pulmonary disease, and pneumonia.
BACKGROUND: Specific allergen from various pollen types has been found to be carried through the outdoor air, not only by intact pollen grains, but also by much smaller, paucimicronic particles. There is no complete agreement on whether, for birch (Betula), the seasonal appearance of atmospheric pollen allergen follows the fluctuation pattern of the pollen season. METHODS: Assessment of birch-pollen allergen in size-fractionated ambient aerosol was performed by descending elution of allergen from impaction strips of a five-stage cascade impactor, and compared with atmospheric birch-pollen concentrations as measured with a volumetric pollen trap. RESULTS: An overall similarity in the courses of the seasonal presence was found for both birch pollen and allergen in particles of all paucimicronic size fractions, although some airborne allergen was detected before and after the birch-pollen season. CONCLUSIONS: Transfer of pollen allergen to both natural and pollutant environmental dust particles is thought to be the probable explanation of secondary allergen carriage by paucimicronic particles. Until simple techniques for direct and rapid assessment of atmospheric pollen allergen become available, the pollen count gives sufficiently reliable information about the seasonal course of airborne pollen allergen.
The increasing mobility of Europeans for business and leisure has led to a need for reliable information about exposure to seasonal airborne allergens during travel abroad. Over the last 10 years or so, aeropalynologic and allergologic studies have progressed to meet this need, and extensive international networks now provide regular pollen and hay-fever forecasts. Europe is a geographically complex continent with a widely diverse climate and a wide spectrum of vegetation. Consequently, pollen calendars differ from one area to another; however, on the whole, pollination starts in spring and ends in autumn. Grass pollen is by far the most frequent cause of pollinosis in Europe. In northern Europe, pollen from species of the family Betulaceae is a major cause of the disorder. In contrast, the mild winters and dry summers of Mediterranean areas favor the production of pollen types that are rarely found in central and northern areas of the continent (e.g., the genera Parietaria, Olea, and Cupressus). Clinical and aerobiologic studies show that the pollen map of Europe is changing also as a result of cultural factors (e.g., importation of plants for urban parklands) and greater international travel (e.g., the expansion of the ragweed genus Ambrosia in France, northern Italy, Austria, and Hungary). Studies on allergen-carrying paucimicronic or submicronic airborne particles, which penetrate deep into the lung, are having a relevant impact on our understanding of pollinosis and its distribution throughout Europe.
Knowledge of the taxonomic, physiologic, biologic, and ecologic characteristics of allergenic domestic mites contributes to the understanding of the causation of many cases of allergic asthma, and to the measures to be taken to control excessive mite occurrence in homes. Domestic mites, i.e., the combined group of storage mites living in the home environment and of pyroglyphid house-dust mites, belong to the subclass of the acari. This comprises also many other mites of medical and economic importance, together with thousands of free-living mites. Because of some species-specific properties of their allergenic products, it is important that the producing mite is always correctly identified. In spite of their small size (approx. 0.5 mm), domestic mites have well-developed and elaborate systems of respiration, digestion, and water balance, enabling them to live and survive in the various habitats of the home environment. Knowledge of the effects of the various and changing ecologic conditions in the home environment is helpful in developing strategies to prevent the establishment and growth of large populations of allergenic domestic mites.
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Asthma is an inflammatory disease of the airways, and exacerbations of this disease have been associated with high levels of air pollution. The objective of this study was to examine whether ambient air pollution and/or allergen exposure induces inflammatory changes in the upper airways of asthmatics. Sixty patients with intermittent to severe persistent asthma visited the Hospital's Out Patient Clinic every 2 wk for a period of 3 mo, and on each visit a nasal lavage was obtained. Associations between nasal inflammatory parameters and seasonal allergens and/or air pollution exposures were analyzed using linear regression analysis. The study ran from July 3 to October 6, 1995, during which period ozone (8-h mean: 80 micrograms/m3) and PM10 (24-h mean: 40 micrograms/m3) were the major air pollutants; the major aeroallergen was mugwort pollen (24-h mean: 27 pollen grains/m3). Effects on both cellular and soluble markers in nasal lavage were demonstrated for both ozone and mugwort pollen, but not for PM10. Ambient ozone exposure was associated with an increase in neutrophils (112% per 100 micrograms/m3 increase in 8-h average ozone concentration), eosinophils (176%), epithelial cells (55%), IL-8 (22%), and eosinophil cationic protein (ECP) (19%). Increases in environmental mugwort pollen counts were associated with an increase in nasal eosinophils (107% per 100 pollen/m3) and ECP (23%), but not with neutrophils, epithelial cells, or lL-8. This study demonstrated that both ambient ozone and allergen exposure are associated with inflammatory responses in the upper airways of subjects with asthma, although the type of inflammation is qualitatively different.
In a study during the 1993 grass pollen season at Leiden, the relationship between atmospheric pollen allergen carried by five size fractions of pauci-micronic (few microns) particles and the grass pollen count was investigated. Sampling was carried out on dry days, and atmospheric pollen allergen in the particle fractions was assessed by a RAST-inhibition assay while grass pollen quantities were measured with a volumetric pollen trap. It appears that the atmospheric presence of grass pollen allergen in all size fractions is restricted mainly to the period of presence of grass pollen grains. Before and after the grass pollen season atmospheric grass pollen allergen quantities are generally very low. It is concluded that a routinely performed grass pollen count is a reliable measurement for the estimation of the amount of atmospheric grass pollen allergen, also in the pauci-micronic particle fraction.
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The aim of the present work was to identify the classic phenological stages, and to understand its relation to catkin differentiation and growth, and its consequences for the start of pollination. Phenological observations and an aeropalynological survey on Corylus avellana, which is an example of an economically and allergologically interesting arboreal plant, were carried out during 1991-1992. The comparison between the different phenological phases and the aeropalynological data, showed that the pollen trap recorded hazel-pollen presence in the atmosphere immediately after the pollen release from the orchard. The start of catkin elongation in late winter, after the chilling requirement has been fulfilled, could be used to indicate the beginning of heat accumulation necessary for pollination.
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In June 1988, during the grass-pollen season in Leiden, The Netherlands, outdoor airborne particulate matter was collected and separated into fractions according to aerodynamic sizes (greater than or equal to 10 microns, 4.9-10 microns, 2.7-4.9 microns, 1.3-2.7 microns, 0.6-1.3 microns, less than or equal to 0.6 microns), with a cascade impactor mounted on top of a high volume sampler. The different fractions were tested for the presence of grass-pollen allergenic activity using a RAST-inhibition assay: specific IgE-antibody-containing patient serum was applied on the particle-loaded impaction strips, and the serum was recovered by descending elution for further analysis in the RAST. Simultaneously, continuous measurements were made of the airborne grass-pollen concentration using a volumetric pollen trap. Sampling observations lasting 7-9 hr during a period with relatively high airborne grass-pollen concentrations showed reliably detectable amounts of grass-pollen allergen, not only in the first impaction stage where intact pollen were collected, but also in the lower stages collecting the smaller, paucimicronic and submicron atmospheric aerosol fraction. It is evident that this result has serious implications for the understanding of the bronchial symptoms frequently seen in hay fever patients on days with high pollen concentrations in the air.
Using an in-vitro test, the presence of formaldehyde-specific IgE antibodies was investigated in sera from four groups of individuals exposed to formaldehyde by different routes and concentrations. Group (A) 28 subjects living or working in rooms or places where formaldehyde-containing construction materials were used; (B) 18 subjects occupationally exposed to relatively high concentrations of formaldehyde; (C) 12 paramedic employees working in a renal dialysis unit where formaldehyde-sterilized dialysers were being used; and (D) 28 subjects undergoing haemodialysis with these formaldehyde-sterilized dialysers. Formaldehyde-specific IgE antibodies could be detected in only one of the 86 serum samples. This particular sample was from a worker occupationally exposed to formaldehyde (group (B], but who did not show any work-related symptoms. In two pools of control sera from unexposed subjects no specific IgE antibodies to formaldehyde were detected. It is concluded that exposure to formaldehyde, even in relatively high concentrations, rarely evokes the production of specific IgE antibodies. The presence of these specific antibodies is not necessarily attended by allergic symptoms. On the other hand, the symptoms supposed to be related to formaldehyde exposure and reported in this study by 24 out of 28 subjects in group (A), and some of the subjects in groups (B) and (C), cannot be attributed to an IgE-mediated sensitization to formaldehyde.
In this paper we present the results of volumetric sampling of the airborne pollen grains of the Oleaceae family (Fraxinus, Ligustrum and Olea) in some European towns, in the period from 1982 to 1986. The sampling and appraisal of pollen content in the air is of particular interest to clinicians and allergic patients in order to assess exposure to the various pollen types in relation to allergy. In the Oleaceae family, the most allergenic pollen is produced by Olea europaea, the olive tree, which in the Mediterranean area has a pollination period lasting from May to the end of June and sometimes causes severe symptoms of pollinosis. In Northern and Central Europe, where there are no olive trees, there are two other commonly occurring genera of the Oleaceae family, namely Fraxinus and Ligustrum, but these have a low frequency of allergic sensitization.