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.

Enhanced Indirect Photochemical Transformation of Histidine and Histamine through Association with Chromophoric Dissolved Organic Matter.

Photochemical transformations greatly affect the stability and fate of amino acids (AAs) in sunlit aquatic ecosystems. Whereas the direct phototransformation of dissolved AAs is well investigated, their indirect photolysis in the presence of chromophoric dissolved organic matter (CDOM) is poorly understood. In aquatic systems, CDOM may act both as sorbent for AAs and as photosensitizer, creating microenvironments with high concentrations of photochemically produced reactive intermediates, such as singlet oxygen (1O2). This study provides a systematic investigation of the indirect photochemical transformation of histidine (His) and histamine by 1O2 in solutions containing CDOM as a function of solution pH. Both His and histamine showed pH-dependent enhanced phototransformation in the CDOM systems as compared to systems in which model, low-molecular-weight 1O2 sensitizers were used. Enhanced reactivity resulted from sorption of His and histamine to CDOM and thus exposure to elevated 1O2 concentrations in the CDOM microenvironment. The extent of reactivity enhancement depended on solution pH via its effects on the protonation state of His, histamine, and CDOM. Sorption-enhanced reactivity was independently supported by depressed rate enhancements in the presence of a cosorbate that competitively displaced His and histamine from CDOM. Incorporating sorption and photochemical transformation processes into a reaction rate prediction model improved the description of the abiotic photochemical transformation rates of His in the presence of CDOM.

Sunlight, immunosuppression and skin cancer: role of histamine and mast cells.

1. The development into tumours of skin cells transformed by ultraviolet (UV) B radiation of wavelengths 290-320 nm is enhanced by the ability of UVB to suppress an immune response that would otherwise destroy them. Ultraviolet B-induced immunomodulation may be by multiple mechanisms, but generally manifests in an antigen-presenting cell defect and an altered cytokine environment in the draining lymph nodes. 2. Immune responses to microbial or self-antigens may be dysfunctional by similar mechanisms following UVB exposure. 3. Earliest-acting intermediates in the initiation of UVB-induced immunosuppression are the UVB absorbers (photoreceptors) of the skin, notably DNA resulting in immunoregulatory cytokine production, and trans-urocanic acid (UCA), which, upon isomerization to its cis isomer, signals downstream immunosuppressive events. 4. In mice, dermal mast cells are critical to UVB-induced systemic immunomodulation. In mice, there is a functional link as well as a linear relationship between the prevalence of histamine-staining dermal mast cells and the log of the dose of UVB required for 50% immunosuppression. Studies with histamine receptor antagonists support histamine as the main' product of mast cells involved. Histamine acts in large part via a prostanoid-dependent pathway. 5. Approximately 50% of humans and greater than 90% of patients with non-melanoma skin cancer are UVB susceptible for suppression of a contact hypersensitivity response. Neither cytokine polymorphisms nor UVB-induced levels of cis-UCA in irradiated skin have been linked to UVB susceptibility. Patients with basal cell carcinomas (BCC) have an increased dermal mast cell prevalence in non-sun-exposed buttock skin. We propose that mast cells function in humans, as in mice, by initiating immunosuppression and, thereby, allowing a permissive environment for BCC development.

[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.

Radiation therapy in a case of systemic mastocytosis: evaluation of histamine levels and mucosal effects.

Plasma histamine levels were obtained during palliative radiation therapy of the spine involved with systemic mastocytosis in a 68-year-old woman. Baseline plasma histamine levels were obtained before irradiation and compared to levels obtained on the third, fifth, eighth, and tenth treatment days. Despite concerns regarding histamine release with mast cell destruction following irradiation, plasma histamine levels remained within normal limits. No change in dermatologic or other systemic manifestations were observed. No untoward systemic or localized sequelae associated with mast cell degranulation in response to the administered large field of radiation was observed. Effective palliation was accomplished, and it was concluded that radiation therapy can effectively be applied in treatment of systemic mast cell disease without significant morbidity.

[The combined action of ionizing radiation and a heat load on the content of biogenic amines in the blood of guinea pigs with anaphylactic shock]. / Kombinirovannoe deistvie ioniziruiushchego izlucheniia i teplovoi nagruzki na soderzhanie biogennykh aminov v krovi morskikh svinok pri anafilaticheskom shoke.

The anaphylactic shock and alterations in the epinephrine and norepinephrine content of the blood were inhibited in guinea pigs which were repeatedly kept at high temperature (50 degrees C). Preirradiation with a dose of 1 Gy prevented this effect.

[The effect on an impulse electromagnetic field on the bioamine allowance of the spinal ganglion in rats under whole-body exposure]. / Vliianie impul'snogo élektromagnitnogo polia na sostoianie bioaminnoi obespechennosti spinnomozgovogo gangliia krys v usloviiakh total'nogo vozdeistviia.

In experiments with albino male rats subjected to whole-body pulse electromagnetic irradiation of 100 mTl magnetic induction, the luminescent histochemical methods and the subsequent microspectrofluorometry were used to determine the content of biogenic amines (catecholamines, serotonin, and histamine) in spinal ganglia neurons. Significant changes were revealed not only in the content of all studied bioamines but in the histamine/serotonin ratio as well.

[Changes in metabolism of the nervous system in exposure to ionizing radiation at supralethal doses]. / Izmeneniia metabolizma nervnoi sistemy pri deistvii ioniziruiushchei radiatsii v sverkhletal'nykh dozakh.

Some biochemical disorders in the animals' central nervous system mainly in brain have been analysed after the exposure to superlethal doses of ionizing radiation as well in a state of the so-called early transient incapacity. The metabolism of gamma-aminobutyric acid, ammonia, histamine, cyclic nucleotides, prostaglandins and other biologically active substances is compared. Their investigation as metabolic regulators and modulators for nerve tissue seems to be of particular importance for deciphering the molecular mechanisms of changes in the central nervous system functional state and for discovering the possibility of its maintaining at a given level of activity.

Simple stability-indicating assay for histamine solutions.

A chemical stability-indicating assay for the routine analysis of histamine in isotonic-phosphate buffer solutions was developed and evaluated. A quantitative colorimetric assay was developed by adapting the Pauly reaction specific for the imidazole group for the determination of histamine in buffer solutions. Stock solutions of histamine diphosphate 1 mg/mL were diluted with isotonic phosphate buffer to produce standards for an imidazole-group assay and for the USP assay method based on the Folin reaction of free amino groups. The specificity of the assays was evaluated by subjecting samples to ultraviolet irradiation and heat for various time periods and then analyzing for histamine content. Both of the colorimetric assays provided reproducible linear calibration curves passing through the origin for histamine diphosphate concentrations. For the Pauly-reaction assay, the average coefficients of variation between and within runs were 0.5% and 0.1%, respectively. The assay had recoveries of 100.6% and 100.8% at 8 and 25 micrograms/mL of histamine diphosphate concentrations, respectively, and a sensitivity of 3 micrograms/mL. Based on the results of the Pauly-reaction assay, irradiation caused decreases in the apparent concentrations as large as 69.2% depending on the duration of the irradiation and distance from the light source. When the histamine diphosphate solutions were stored in the dark at 60 degrees C for five days, a decrease of only 6.3% occurred. Based on the results of the Folin-reaction assay, irradiation caused increases in the apparent concentrations as large as 50.6%. The Pauly colorimetric assay based on the imidazole group appears to be more appropriate for histamine solutions than the amino-group assay based on the Folin reaction.

Radical formation in single crystals of aromatic amines and radical transformation by light.

Single crystals of the four aromatic bioamine salts phenylethylamine hydrochloride, tyramine hydrochloride, tryptamine hydrochloride, and histamine dihydrochloride were grown in various states of deuteration. Free radicals were produced by exposure to X-rays between 77 and 300 K and investigated by electron spin resonance spectroscopy. Dissociation of atomic hydrogen from C beta of the aliphatic chain occurs in all compounds studied except tryptamine. However deamination as usually present in the analogous amino acids is not found. The C beta-radical is characterized by an anisotropic H alpha-splitting and two isotropic H beta-splittings. The latter splittings depend strongly on temperature in tyramine. In comparison to the analogous amino acids, radical formation in the aromatic residues is favoured. Among the seven different aromatic radicals found only one is identified in histamine but two in each of the three other bioamines. Two of these are characterized by hydrogen dissociation which occurs in phenylethylamine and tyramine. One hydrogen addition radical is found in each of the three compounds phenylethylamine, tyramine and histamine. In tryptamine two different addition radicals are detected. One of the two products can be converted into the other by visible light. The reverse process is induced by heat, thus permitting the switching of the radical site reversibly between two different structures.

[Effect of laser irradiation on the serological and morphological indices of experimental immune reactivity (a preliminary report)]. / Vliianie na lazernoto obluchvane vurkhu niakoi serologichni i morfologichni pokazateli na imunnata reaktivnost v eksperiment (predvaritelno suobshtenie).

The authors examined guinea pigs, irradiated for a period of six days with helium-neon lazer according to a scheme, proposed by them. They determined the changes in the complement serum activity, blood level of heparine and histamine as well as histologic changes in adrenals, liver and spleen. When they compared the control animals (nonirradiated) with the experimental animals, they established a statisticaly significant elevation of the complement activity in serum, a tendency to lowering of histamine with an increase of heparine and hyperplastic reaction in zona glomerulosa of the adrenals. The obtained results suggested stimulation of immune mechanisms with antiallergic and antinflammatory effect.

Regional levels of histamine in rat brain after microwave irradiation: evidence for artifacts in the enzymatic--isotopic assay.

Histamine levels in the brain, measured fluorimetrically, were similar for rats killed by decapitation and microwave irradiation. However, enzymatic--isotopic assay yields 5--20 times higher value for microwave irradiation versus decapitation. Thin layer chromatography of the methylated products in the enzymatic--isotopic assay indicated the formation of artifacts following microwave irradiation. The results strongly suggest that a combination of microwave irradiation and enzymatic--isotopic assay is not suitable for histamine analysis in the rat brain.