Currently diagnosis of allergic diseases is based largely on results of skin tests and laboratory methods of quantification of total and specific immunoglobulins E in serum in addition to clinical and instrumental data. However, in recent years it has been showed that systemic atopy is not always registered with these methods and specific immunoglobulins E may not have diagnostic concentrations in serum that makes it difficult to diagnose allergic diseases. The article presents a clinical case of combination of asthma and allergic rhinitis caused by local IgE production with normal level of serum I-4, reduced levels of IgG1, IgG2 and serum and secretory IgA in child aged 3 years.

Background. To explore the stability of histamine solutions of low concentrations sterilized by autoclaving and filtration as well as the possibilities of storage and use of these solutions after 1-fold and 5-fold freezing and defrosting. Methods. Histamine dihydrochloride solutions at a concentration of 10 μg/ml were sterilized by the membrane filtration or the autoclaving at 121 °C for 30 minutes. The solutions were frozen in sterile insulin syringes, followed by 1- and 5-fold defrosting. Skin prick tests have been performed with the resulting solutions. Results. When comparing the results of skin prick testing performed with autoclaved and sterilized by the filtration histamine, no statistically significant differences were found (p>0,05). Comparison of the results of skin prick tests performed with histamine that hadn't been frozen before, after 1- and 5-fold freezing and defrosting showed no statistically significant differences (p>0,05). Conclusion. It has been shown that histamine solutions sterilized by autoclaving at 121 °C for 30 minutes followed by repeated freezing and defrosting don’t change their biological activity substantially.

Objective. To assess the effectiveness of the low-dose air ozonation for disinfection of the air in the working room. Materials and methods. We investigated 90 air samples (3 samples were taken weekly before and after the production meeting using the automatic sampling device of biological aerosols of air PU-1B). The total bacterial contamination, the content of staphylococci and mold spores were determined. Ozonation of the room (83.3 m3) was carried out for 20 minutes by means of domestic ozonator. The accumulated dose of ozone was 133.3 mg (1.6 mg/m3). Statistical data processing was carried out using the MedStat licensed program. The median, median error (Me me), left and right 95 % confidence intervals (95 % CI) were calculated. Paired comparisons were made using Wilcoxon's T-test. Results. After the meeting, the total bacterial contamination of the air was 56.0 9.3 (47.078.0) CFU. The content of staphylococci and mold spores in the air was 85.5 12.5 (76.0100.0) and 44.5 6.5 (32.054.0) CFU, respectively. After ozonation, the total bacterial contamination of the air was 14.5 3.6 (10.021.0) CFU. The content of staphylococci and mold spores in the air after ozonation was 35.5 6.7 (25.052.0) and 26.0 5.0 (18.032.0) CFU, respectively. Ozonation of the room provided a significant decrease (p 0.001) in all three of the above indicators. The room ozonation carried out promoted a reliable decrease (p 0.001) in all the above mentioned parameters. Conclusions. The above data and analysis of the literature show the possibility of using low doses of ozone for the prevention of bacterial, fungal and viral infections including SARS-CoV-2. Further study and development of reasonable modes of ozone disinfection, including low doses of ozone, is needed, as well as determination of the efficiency degree of air disinfection with non-toxic gas concentrations.