The excited-state interaction of resazurin and resorufin with amines in aqueous solutions. Photophysics and photochemical reactions.

The photophysics and photochemical behavior of the phenoxazin-3-one dyes, resazurin and resorufin, have been studied in aqueous solutions. The irradiation of resazurin in the presence of amines leads to deoxygenation of the N-oxide group, giving resorufin. This photoreaction is highly dependent on the amine structure and is efficient only in the presence of tertiary aliphatic amines. The absorption and fluorescence properties of these dyes are dependent on pH. At pH above 7.5 both dyes are in their anionic form. For resorufin this form is highly fluorescent (phiF = 0.75). At lower pH the fluorescence is strongly reduced. The N-oxide dye presents a very weak fluorescence quantum yield (0.11), which also is reduced at low pH. Flash photolysis experiments allowed characterization of the triplet state and the transients formed after irradiation of these dyes in the absence and presence of amines. The triplet quantum yields are 0.08 for resazurin and 0.04 for resorufin. The photodeoxygenation of N-oxide in the presence of amines occurs from the triplet state.

Synthesis, structure, and features of anilinium anilinomethanesulfonates.

Two series of anilinomethanesulfonate derivatives, the anilinium and p-toluidinium anilinomethanesulfonates, were synthesized. They present interesting spectroscopic features and can be used as characteristic derivatives of the parent compounds. These series allow the easy study of the N--H stretching frequencies of the secondary amine whereas difficulties are encountered with the parent compounds due to the occurrence of O--H stretching bands in the same frequency range. All three compounds present a common fragmentation pattern in mass spectral analysis. Through these analyses, the salt structure of the anilinium anilinomethanesulfonates is demonstrated in opposition to a sulfonamide structure, giving further support to the salt structure of other series previously reported.

Reaction of sodium hydroxymethanesulfonate with substituted anilines.

The reactions of substituted anilines with sodium hydroxymethanesulfonate to form the anilinomethanesulfonates were studied in 50% ethanol--water at 0--50 degrees. The Arrhenius rate constants were 5.4 X 10(10) exp(--16,400/RT) M-1 min-1 for aniline, 4.8 X 10(11) exp(--17,100RT) M-1 min-1 for p-anisidine, 7.1 X 10(9) exp(--14,500/RT) M-1 min-1 for p-toluidine, 1.5 X 10(13) exp(--21,100/RT) M-1 min-1 for p-chloroaniline, and 1.1 X 10(12) exp(--19,800/RT) M-l min-1 for p-bromoaniline. Some equilibrium constants and hydrolysis rate constants of the products also were calculated. Hydrolysis rate constants were temperature independent. These reactions had a p value of --3.40 in the Hammett equation. The solvent concentrations used proved to be very convenient for obtaining high yields of the aminomethanesulfonates.

[Therapy for smoking: a challenge for the physician]. / Rauchertherapie: Eine ärztliche Herausforderung.

Smoking cessation is an outstanding and absolute necessity. But there is less possibility of permanent cessation by the first treatment. Combined therapy (e. g. psychological and drugs etc) will reduce relapses. Frequent information of the public via the media is most important and improves the changes of lasting smoking cessation. No doubt smoking cessation has great relevance in health policy and should be supported by all institutions concerned.

Pneumoconiosis and systemic sclerosis following 10 years of exposure to polyvinyl chloride dust.

The case history is presented of a 58 year old man who was exposed to thermoplastic dusts, mainly polyvinyl chloride (PVC), for 10 years. Radiography and high resolution computed tomographic scans of the lungs suggested both pneumoconiotic and scleroderma-like lesions. Transbronchial biopsy revealed foreign body granulomas with macrophages laden with birefringent inclusions which ultrastructurally resembled PVC dust. Biopsy samples of thickened skin showed histological evidence of extensive fibrosis. During follow up Raynaud's phenomenon and oesophageal involvement developed. The antinuclear antibody titre was 1:640, and the Sc1-70 subset was positive. It is concluded that exposure to PVC dust may cause pneumoconiosis and secondary systemic sclerosis.

Seasonal and allergenic predictors of bronchial responsiveness to distilled water.

To evaluate a possible seasonal change in bronchial responsiveness and the relation of such change to atopy, we administered 2,537 bronchial challenge tests in winter and spring to a dynamic population cohort of children 7 to 10 yr of age. The bronchial challenge test consisted of 10 min of tidal inhalation of an aerosol of ultrasonically nebulized distilled water; the resulting percentage decrease in FEV1 (dFEV1%) was recorded. Atopy was determined on the basis of skin-test positivity (any wheal with a diameter greater than that obtained with a positive control) to seven allergens (cat dander, dog dander, house-dust mite, birch, raygrass, orchard grass, and Alternaria). Greater bronchial responsiveness in winter was independently and significantly predicted by a physician's diagnosis of asthma (difference in dFEV1%, 5.6; 95% confidence intervals [95% CI], 2.8 to 8.5; p = 0.0001) and by shortness of breath (difference in dFEV1%, 4.2; 95% CI, 2.1 to 6.3; p = 0.0001). These factors were also predictive of greater responsiveness in the spring, as was atopy (difference in dFEV1%, 3.2; 95% CI, 1.8 to 4.6; p = 0.0001). Analysis of specific allergens further revealed that reactivity to perennial allergens (house-dust mite, cat dander) was predictive of bronchial responsiveness in both winter and spring. However, the change in responsiveness between seasons was most significantly predicted by allergy to seasonal grass pollen, i.e., ragweed or orchard grass (change in dFEV1%, 2.6; 95% CI, 0.6 to 4.5; p = 0.01). In summary, our study demonstrates increased bronchial responsiveness in spring among children allergic to grass pollen.(ABSTRACT TRUNCATED AT 250 WORDS)

Acidic particles and lung function in children. A summer camp study in the Austrian Alps.

Epidemiological studies have repeatedly demonstrated the effects of acidic particles on lung function. Three consecutive panels of children participating in a summer camp in the Austrian Alps were investigated. On-site pollution assessment consisted of 24-h measurements of particulate matter < 10 microns and the hydrogen, sulfate, and ammonium ion components. The 24-h maximums of ozone and daily pollen counts were also established. For 47, 45, and 41 subjects, daily FEV1, FVC, and peak expiratory flow were recorded. Fifteen percent, 11%, and 5% of participants, respectively, reported current asthma medication, indicating a markedly increased prevalence of respiratory disease. Mean levels of ambient pollutants were approximately 15% higher for the first panel than for the other two panels, but the hydrogen ion (H+) component was twice as high for Panel 1. The maximum H+ exposure during Panel 1 was 84 nmol/m3 (4 micrograms/m3 H2SO4 equivalent). For FEV1 in Panel 1, a significant decrease of -0.99 ml per nmol/m3 H+ (p = 0.01) was observed. For Panel 2, the FEV1/H+ coefficient was found to be similar (-0.74 ml per nmol/m3 H+; p = 0.28), while for Panel 3 it was in the opposite direction (0.10 ml per nmol/m3 H+; p = 0.83). The decrease in FEV1 observed in Panel 1 was more pronounced when the mean exposure during the previous 4 d was considered (-2.99 ml FEV1 per nmol/m3 H+; p = 0.004). We conclude that summer haze acidic particles may be associated with transient decreases in lung function in children.