Cytological damage of nasal epithelium associated with decreased glutathione peroxidase in residents from a heavily polluted city

The association between acetaminophen and asthma: is there anything to learn from the upper airways?

PURPOSE OF REVIEW

To examine the literature evidence for the association between acetaminophen (paracetamol) use and development of rhinitis.

RECENT FINDINGS

Increased use of acetaminophen (paracetamol) as the favored antipyretic during pregnancy and infancy has been hypothesized to be a risk factor for the development of asthma. There is a paucity of well designed birth cohort studies to examine paracetamol as a risk factor in the development of rhinitis. Confounding by antibiotic use, viral infections, and recall bias are problematic for many of the studies that are published.

SUMMARY

Prospective birth cohorts need to dedicate sufficient time and research personnel to adequately assess paracetamol exposure as a primary variable of interest rather than as an incidental exposure variable collected during routine questionnaire administration.

Developmental expression of plasma glutathione peroxidase during mouse organogenesis

Plasma glutathione peroxidase (pGPx) is an extracellular antioxidative selenoenzyme which has been detected in various adult tissues, but little is known about the expression and distribution of pGPx during embryogenesis. To investigate the expression patterns of pGPx during embryogenesis, we performed quantitative real-time PCR, in situ hybridization, Western blot, and immunohistochemistry analyses in whole embryos or each developing organ of mice on embryonic days (E)7.5-18.5. In whole embryos of E7.5-8.5, pGPx mRNA was more typically expressed in extra-embryonic tissues including ectoplacental cone, trophectoderm, and decidual cells than in embryos. However, after E9.5, pGPx mRNA and protein levels were increased in the embryos with differentiation and growth, but trended to gradually decrease in the extra-embryonic tissues until E18.5. In sectioned embryonic tissues on E13.5-18.5, pGPx mRNA and protein were mainly expressed in the developing nervous tissues, the sensory organs, and the epithelia of lung, skin, and intestine, the heart and artery, and the kidney. In particular, pGPx immunoreactivity was very strong in the developing liver. These results indicate that pGPx is spatio-temporally expressed in various embryonic organs as well as extra-embryonic tissues, suggesting that pGPx may function to protect the embryos against endogenous and exogenous reactive oxygen species during organogenesis.

Endogenous antioxidants and nasal human epithelium response to air pollutants: genotoxic and inmmuno-cytochemical evaluation

Nasal epithelium is a source for identifying atmospheric pollution impact. Antioxidants play a relevant role in the protection of the cells from environmental injury, but scarce information is available about the interaction of endogenous antioxidants and genotoxic damage in nasal epithelium from urban populations highly exposed to traffic-generated air pollutants. An immunocytochemical and genotoxic evaluation was implemented in nasal cell epithelium in a population chronically exposed to atmospheric pollution from autumn 2004 to autumn 2005. Superoxide dismutase (SOD) and Catalase (CAT) were evaluated in nasal scrapings by morphometry and genotoxicity by comet assay. An increase in DNA damage correlates with a decrease in SOD and CAT in nasal cells during autumn and the inverse result was observed during summer (R = 0.88). Not only should exogenous antioxidant supplements be encouraged, but also a healthy diet to strengthen intracellular defenses against oxidative stress induced by exposure to air pollutants.

Preparation and evaluation of fexofenadine microemulsion for intranasal delivery

To enhance the solubility and bioavailability of poorly absorbable fexofenadine, microemulsion system composed of oil, surfactant and co-surfactant was developed for intranasal delivery. Phase behavior, particle size, viscosity and solubilization capacity of the microemulsion system were characterized. Histopathology and in vivo nasal absorption of the optimized microemulsion formulations were also investigated in rats. A single isotropic region was found in the pseudo-ternary phase diagrams developed at various ratios with Lauroglycol 90 as oil, Labrasol as surfactant and Plurol oleiqueCC49 or its mixture with PEG-400 (1:1) as cosurfactant. An increase in the microemulsion region in pseudo-ternary phase systems was observed with increased surfactant concentration. The optimized microemulsion formulations showed higher solubulization of fexofenadine, i.e., F1 (22.64mg/mL) and F2 (22.98mg/mL), compared to its intrinsic water solubility (1.51mg/mL). Nasal absorption of fexofenadine from these microemulsions was found to be fairly rapid. T(max) was observed within 5min after intranasal administration at 1.0mg/kg dose, and the absolute bioavailability (0-4h) was about 68% compared to the intravenous administration in rats. Our results suggested that these microemulsion formulations could be used as an effective intranasal dosage form for the rapid-onset delivery of fexofenadine.