Sex differences in the development of airway epithelial tolerance to naphthalene.

Exposure to air pollution has been linked to pulmonary diseases. Naphthalene (NA), an abundant polycyclic aromatic hydrocarbon in tobacco smoke and urban air, is a model toxicant for air pollution effects in the lung. Repeated exposures to NA in male mice result in tolerance, defined as the emergence of a resistant cell phenotype after prior exposure. Tolerance has not been studied in females. Females have sex differences in airway epithelial responses and in the prevalence of certain airway diseases. Male and female mice were exposed to a tolerance-inducing regimen of NA, and lungs were examined by airway level to characterize the cellular changes associated with repeated NA exposure and to assess the expression of genes and proteins involved in NA bioactivation and detoxification. The airway epithelium in treated males resembled that of controls. Females in the tolerant state were characterized by dense populations of ciliated cells in midlevel, distal, and bifurcating airways and a lower abundance of Clara cells at all airway levels. Cytotoxicity following a secondary challenge dose was also greater in females than males. Furthermore, females had decreased gene/protein expression of CYP2F2, a P-450 that metabolizes NA to a toxic epoxide, and glutamate-cysteine ligase, the rate-limiting enzyme in glutathione synthesis, than NA-tolerant males at all airway levels examined. We conclude that, while females develop tolerance, sex differences exist in the tolerant state by airway level, and females remain more susceptible than males to repeated exposures to NA.

Aeromedical transport of patients with post-traumatic cardiac arrest.

Patients experiencing cardiac arrest secondary to trauma make up 8% to 15% of air ambulance scene flights in reported series. Our study examined the role of aggressive physician intervention at the accident scene in conjunction with rapid air transport to a trauma center in reducing the mortality after post-traumatic cardiac arrest. We retrospectively studied 67 patients who experienced cardiac arrest before the arrival of the flight team. Fifty-eight patients were victims of blunt trauma, and nine sustained penetrating trauma. Forty-seven patients were transported to the base hospital; 20 were pronounced dead at the scene after resuscitation attempts were made. Six patients developed a pulse and blood pressure and were hospitalized; none survived to hospital discharge. Review of autopsy data revealed that the majority of patients had head or thoracoabdominal injuries or both that were incompatible with life. We conclude that physician intervention at the scene and rapid aeromedical transport are not likely to improve mortality after traumatic cardiac arrest.

Occurrence of human-associated yeasts in bivalve shellfish from Long Island Sound.

Candida parapsilosis, C. tropicalis, and Torulopsis glabrata were the human-associated yeasts most frequently isolated from quahogs, oysters, and mussels collected from four estuarine areas along the northern shore of Long Island Sound. Some inconsistency and seasonal variation in the occurrence of these and other yeast species were noted. In particular, C. albicans densities were greatest during colder months in the more heavily polluted waters. A total of 347 yeasts were isolated and cultured at 37 degrees C and, of these, 219 of 62% were human-associated forms. Generally, these yeasts in the animals sampled reflected the overall pollution status of the estuary from which they were taken. This study represents a clear demonstration of potentially pathogenic yeasts in a valuable marine resource.