Decreased viability and proliferation of CHANG conjunctival epithelial cells after contact with ultraviolet light-irradiated pollen.

CONTEXT: Contact with pollen is the major reason for the development of allergic symptoms on the ocular surface leading to a significant increase of allergic diseases worldwide. Environmental changes such as increased ultraviolet (UV) radiation and air pollution are discussed as contributory causes for this increase. OBJECTIVE: We investigated the effect of UV light on the histamine content of pollen and examined if an irradiation of pollen affects the viability and proliferation of conjunctival cells. MATERIALS AND METHODS: Alder (Alnus glutinosa) and hazel (Corylus avellana) pollen were irradiated for different time periods with sunlight, UV-A or UV-B light and the histamine content was analysed and compared with non-irradiated pollen. Conjunctival epithelial cells (CHANG cells) were exposed to irradiated and non-irradiated pollen followed by an assessment of cell viability with the colorimetric MTS test and the impedance-based measurement of cell proliferation using the xCELLigence real-time analysis system. RESULTS: UV light irradiation increased the histamine level of alder and hazel pollen in a dose-dependent manner. CHANG cells treated with irradiated pollen induced a statistically significant higher decrease of cell viability than treatment with non-irradiated pollen. DISCUSSION AND CONCLUSIONS: Our results indicate that UV light is able to alter pollen thus making them more harmful for conjunctival cells.

[New approach to the study of interaction of amino acid side groups with aryl azides]. / Novyi podkhod k izucheniiu vzaimodeistviia aminokislot po ikh bokovym radikalam s arilazidami.

A new approach to the study of the interaction of amino acid side chains with photoreactive aryl azides was proposed. This approach was based on the drawing together of the reacting groups by the attachment of the reacting compounds to complementary oligonucleotides. Cystamine, histamine, and 1,6-hexamethylenediamine mimicking the cystine, histidine, and lysine residues, respectively, were attached to the 3'-terminal phosphate of the oligonucleotide GGTATCp through a phosphamide bond and used as the targets for photomodification. Derivatives of the oligonucleotide pGATACCAA with the fragment N3C6H4NH- attached directly to its 5'-end by a phosphamide bond or through the spacer -(CH2)nNH- (where n is 2, 4, and 6) were used as photoreagents. Their derivatives containing the same spacer and the N3C6F4CO-NH(CH2)3NH- or 2-N3,5-NO2-C6H3CO-NH(CH2)3NH- residues were also used. The duplexes were photomodified by irradiation with 300-350 nm wavelength light. The maximal yields of the photo-cross-linking were from 22 to 68%. The reagents containing p-azidoaniline residue were found to be the most effective toward the targets. The maximum yields of the photomodification products modeling the side chains of cysteine and lysine were found to vary from 40 to 67% and to depend on the length and the structure of the spacers used. The duplex with the target bearing the imidazole residue (the histidine model) manifested a yield decreased to 25%. This fact was in a good agreement with the data of computer modeling that indicated an unfavorable mutual displacement of the imidazole residue and the photoreactive group.

[The modification of the effect of microwave radiation on the biochemical processes in anaphylactic shock by using exposure to a weak and perturbed geomagnetic field]. / Modifikatsiia vliianiia mikrovolnovogo izlucheniia na biokhimicheskie protsessy pri anafilakticheskom shoke s pomoshch'iu vozdeistviia oslablennogo i iskazhennogo geomagnitnogo polia.

Repeated exposure of guinea pigs to microwave radiation (1 mW/cm2) caused in some animals inhibition of anaphylactic response accompanied by increasing the content of histamine, epinephrine and norepinephrine in the blood. This increase was more pronounced in irradiated guinea pigs died from anaphylactic shock than in nonirradiated animals. The long-term stay in the perturbed and weak geometric field reduced the effect induced by microwave radiation.