FT-IR product study of the reactions of NO3 radicals with ortho-, meta-, and para-cresol.

Product analyses of the NO3 radical-initiated oxidation of ortho-, meta-, and para-cresol have been performed in large-volume chamber systems at the University of Wuppertal (1080 L quartz glass reactor: QUAREC) and the European Photoreactor (EUPHORE), Valencia, Spain. The reaction of O3 with NO2 was used for the in situ generation of NO3 radicals in both QUAREC and EUPHORE. In the QUAREC experiments the gas-phase reaction of ortho-cresol isomer with NO3 yielded (11.5 ± 0.8) % 6-methyl-2-nitrophenol (6M2NP), (4.4 ± 0.3) % methyl-1,4-benzoquinone (MQUIN) and (77.2 ± 6.3) % HNO3. The reaction of NO3 radicals with meta-cresol yielded (21.2 ± 1.4) % 3-methyl-2-nitrophenol (3M2NP), (22.8 ± 1.8) % 3-methyl-4-nitrophenol (3M4NP), (23.5 ± 1.8) % 5-methyl-2-nitrophenol (5M2NP), (4.2 ± 0.7) % MQUIN and (72.3 ± 6.4) % HNO3. In the reaction of NO3 radicals with para-cresol, 4-methyl-2-nitrophenol (4M2NP) and HNO3 were identified as products with yields of (41.3 ± 3.7) % and (85.0 ± 10.2) %, respectively. In the EUPHORE chamber not all products were formed at levels above the detection limit, however, in cases where detection was possible similar product yields were observed. The product formation yields determined in both chambers are compared with available literature data and a gas-phase mechanism is proposed to explain the formation of the products observed from the reaction of NO3 and with cresol isomers.

Serum trace metal and ceruloplasmin variability in individuals treated for pulmonary tuberculosis.

SETTING: Investigation of trace metal behaviour during the treatment of active pulmonary tuberculosis (PTB) patients residing in Romania. OBJECTIVE: To assess, follow and identify serum iron (Fe), copper (Cu) and zinc (Zn) levels in patients diagnosed and treated for active PTB. DESIGN: Chemical and statistical analysis of various biochemical parameters in 47 subjects diagnosed with active PTB and 170 healthy Romanian residents. RESULTS: Copper and ceruloplasmin levels were increased in patients with active PTB compared to the control group (P < 0.01), while the serum Zn level was significantly lower than in healthy subjects (P < 0.01) or within the normal range. The present study shows that there is a significant correlation between serum Cu concentrations and ceruloplasmin. CONCLUSIONS: This study provides preliminary evidence that Zn and Fe redistribution is operating as a primary host defence mechanism to reduce the availability of metals for microbial metabolism during infection. The study also calls attention to the fact that anti-tuberculosis treatment is sufficient to enhance the concentration of the antioxidant species (Cu and ceruloplasmin). The data obtained suggest that serum Cu, Zn and Cu/Zn levels may serve as indirect pointers in the diagnosis of a disease but they cannot be considered as specific markers for TB.