Impact of meteorological parameters and air pollutants on airborne concentration of Betula pollen and Bet v 1 allergen.

The intensity of birch pollen season is expressed by seasonal pollen integral (SPIn, the sum of the mean daily pollen concentration during the birch pollination period) and the amount of Bet v 1 allergen released per birch pollen grain expressed by pollen allergen potency (PAP). Betula pollen and Bet v 1 allergen were simultaneously measured in the air of Bratislava from 2019 to 2022 by using two Burkard traps (Hirst-type and cyclone) in order to evaluate the causes of the seasonal variation in the SPIn and PAP levels. The highest SPIn (19,975 pollen/m3) was observed in 2022 and the lowest one (1484 pollen/m3) in 2021. The average daily PAP level (4.0 pg Bet v 1/pollen) was highest in 2019 and lowest (2.5 pg Bet v 1/pollen) in 2020. We found that seasonal variation in SPIn was associated mainly with the changes in environmental conditions during the pre-season period, whereas the year-to-year variation in PAP levels was attributed to environmental conditions during both pre- and in-season periods. Our results indicate that rainy weather in June 2020 and cold overcast weather in January‒February 2021 resulted in low SPIn in 2021. On the other hand, dry weather in June 2021 and warm weather in January‒February 2022 resulted in high SPIn in 2022. The low average daily PAP level in 2020 was associated with (1) low levels of gaseous air pollutants in March, when the ripening of pollen takes place; (2) an earlier start of the birch main pollen season (MPS); and (3) dry weather during the MPS. On the other hand, high PAP level in 2019 was associated with higher levels of air pollutants in March and during the MPS.

The Impact of Redox, Hydrolysis and Dehydration Chemistry on the Structural and Magnetic Properties of Magnetoferritin Prepared in Variable Thermal Conditions.

Ferritin, a spherically shaped protein complex, is responsible for iron storage in bacteria, plants, animals, and humans. Various ferritin iron core compositions in organisms are associated with specific living requirements, health state, and different biochemical roles of ferritin isomers. Magnetoferritin, a synthetic ferritin derivative, serves as an artificial model system of unusual iron phase structures found in humans. We present the results of a complex structural study of magnetoferritins prepared by controlled in vitro synthesis. Using various complementary methods, it was observed that manipulation of the synthesis technology can improve the physicochemical parameters of the system, which is useful in applications. Thus, a higher synthesis temperature leads to an increase in magnetization due to the formation of the magnetite phase. An increase in the iron loading factor has a more pronounced impact on the protein shell structure in comparison with the pH of the aqueous medium. On the other hand, a higher loading factor at physiological temperature enhances the formation of an amorphous phase instead of magnetite crystallization. It was confirmed that the iron-overloading effect alone (observed during pathological events) cannot contribute to the formation of magnetite.

Longitudinal and Transverse Relaxivity Analysis of Native Ferritin and Magnetoferritin at 7 T MRI.

Magnetite mineralization in human tissue is associated with various pathological processes, especially neurodegenerative disorders. Ferritin's mineral core is believed to be a precursor of magnetite mineralization. Magnetoferritin (MF) was prepared with different iron loading factors (LFs) as a model system for pathological ferritin to analyze its MRI relaxivity properties compared to those of native ferritin (NF). The results revealed that MF differs statistically significantly from NF, with the same LF, for all studied relaxation parameters at 7 T: r1, r2, r2*, r2/r1, r2*/r1. Distinguishability of MF from NF may be useful in non-invasive MRI diagnosis of pathological processes associated with iron accumulation and magnetite mineralization (e.g., neurodegenerative disorders, cancer, and diseases of the heart, lung and liver). In addition, it was found that MF samples possess very strong correlation and MF's relaxivity is linearly dependent on the LF, and the transverse and longitudinal ratios r2/r1 and r2*/r1 possess complementary information. This is useful in eliminating false-positive hypointensive artefacts and diagnosis of the different stages of pathology. These findings could contribute to the exploitation of MRI techniques in the non-invasive diagnosis of iron-related pathological processes in human tissue.

Seasonal variation in the allergenic potency of airborne grass pollen in Bratislava (Slovakia) urban environment.

The Phl p 5 allergen of the plant species Phleum pratense is considered one of the most crucial grass pollen allergenic molecules inducing respiratory allergies. In this study, we evaluated seasonal variation in the concentration of both grass pollen and Phl p 5 allergens as well as the ratio allergen/pollen (pollen potency) in the air of Bratislava during two consecutive years, 2019-2020. These 2 years differed in terms of air pollution, as COVID-19 lockdown in spring 2020 considerably improved air quality in the study area. Air samples were collected using a Hirst-type sampler for pollen detection and the cyclone sampler for aeroallergen detection. In 2020, we observed 80.3% higher seasonal pollen integral, probably associated with the longer pollen season duration, however, 43.6% lower mean daily pollen potency than in 2019. The mean daily pollen value was 37.5% higher in 2020 than in the previous year, while the mean daily allergen value was 14.9% lower in 2020. To evaluate the relationship between the amount of pollen or allergen in the air and selected meteorological factors and air pollution parameters, we used multiple regression analysis. Regarding weather factors, precipitation and relative humidity were significantly associated with pollen and/or allergen concentration, though these associations were negative. Atmospheric pollutants, especially CO, NO2 and O3 were significantly associated with pollen and/or allergen levels. The associations with CO and O3 were positive, while the association with NO2 was negative. Our results indicate that for grasses, an air pollutant that has a significant positive relationship to the ratio of allergen/pollen is nitrogen dioxide.