Narrow-band UVB suppresses nasal symptom and H1R mRNA

Background: Phototherapy with narrow-band ultraviolet B (narrow-band UVB) is clinically effective treatment for atopic dermatitis. In the present study, we examined the effects of intranasal irradiation with narrow-band UVB on nasal symptom, upregulation of histamine H1 receptor (H1R) gene expression and induction of DNA damage in the nasal mucosa of allergic rhinitis (AR) model rat. Methods: AR model rats were intranasally irradiated with 310 nm of narrow-band UVB. Nasal mucosal levels of H1R mRNA were measured using real-time quantitative reverse transcriptase (RT)-PCR. DNA damage was evaluated using cyclobutane pyrimidine dimer (CPD) immunostaining. Results: In toluene 2, 4-diisocyanate (TDI)-sensitized rats, TDI provoked sneezes and H1R gene expression in the nasal mucosa. Intranasal pre-irradiation with 310 nm narrow-band UVB at doses of 600 and 1400, but not 200 mJ/cm2 significantly inhibited the number of sneezes and upregulation of H1R gene expression provoked by TDI. CPD-positive cells appeared in the nasal mucosa after intranasal narrow-band UVB irradiation at a dose of 1400, but not 200 and 600 mJ/cm2. The suppression of TDI-provoked sneezes and upregulation of H1R gene expression lasted 24 h, but not 48 h, after narrow-band UVB irradiation with a dose of 600 mJ/cm2. Conclusions: Intranasal pre-irradiation with narrow-band UVB dose-dependently inhibited sneezes and upregulation of H1R gene expression of the nasal mucosa in AR model rats, suggesting that the inhibition of nasal upregulation of H1R gene expression suppressed nasal symptom. The suppression after narrow-band UVB irradiation at a dose of 600 mJ/cm2 was reversible without induction of DNA damage. These findings indicated that low-dose narrow-band UVB phototherapy could be effectively and safely used for AR treatment in a clinical setting

Ionic state and chain conformation for aqueous solutions of supergiant cyanobacterial polysaccharide

We have investigated the electric conductivity, dielectric relaxation behavior, and viscosity for the aqueous solution of cyanobacterial megamolecules, molecular weight =1.6×10^7 g/mol, named sacran. Sacran is an anionic polyelectrolyte which has carboxylate and sulfate groups on the saccharide chain. The electric conductivity and the zero shear viscosity demonstrated three crossover concentrations at 0.004, 0.02, and 0.1 wt%. The viscosity was found to be scaled as ∼c^, ∼c^, ∼c^, and ∼c^ with increasing the sacran concentration. At 0.1 wt%, the sacran chain formed a weak gel which exhibits macroscopic liquid crystal domains including Schlieren texture. Therefore, these crossover concentrations are considered to be the overlap concentration, entanglement concentration, and gelation concentration (or critical polyelectrolyte concentration), respectively. Dielectric relaxation analysis exhibited the fact that sacran has two types of counterions with different counterion-polyion interaction, i.e., strongly bound and loosely bound counterions. The dielectric parameters such as relaxation time or relaxation strength are sensitive to both the entanglement concentration and the gelation concentration, but not the overlap concentration. The number density of bound counterions calculated from the relaxation strength revealed that the counterion is condensed on the sacran chain with raising the sacran concentrations. The decrease in the charge density of the sacran chain reduces the repulsive force between the chains and this would cause the helix transformation or gelation behavior. The chain conformation of sacran in pure water and the gelation mechanism are discussed in relation with the behavior of polyelectrolytes and liquid crystals