Filterable forms of Nocardia: a preferential site of infection in the mouse brain.

Filterable forms of Nocardia (i.e., filterable nocardiae) are characterized as spherical structures containing many granules. They fluoresce brilliantly under ultraviolet light when stained with acridine orange and are acid-fast in paraffin-containing broth cultures. An accumulation of acid-fast lipochrome bodies, similar to filterable nocardiae, is observed in glial cells of the midbrain nigral lesions found in Parkinson's disease (PD). Preliminary results from experimental infection with filterable nocardiae revealed a possible site of infection in a region of the nervous system associated with movement disorders. Here we examined the preferential site of filterable nocardiae infection in the brain and investigated the effects of various chemicals and biological substances in relation to this preferential site on nocardiae growth in vitro. Examination of tissue samples immunostained for filterable nocardiae revealed that neurons in the olfactory bulbus and the midbrain periaqueductal gray area were immunopositive for filterable nocardiae. Several erythrocytes within blood vessels of the brain were also immunopositive. In addition, a dose-dependent relationship was observed between the growth of filterable nocardiae and erythrocyte lysates. These results suggest first that the preferential site of infection for filterable nocardiae might be erythrocytes, but could also be neurons in the bulbus olfactorius as well as in the midbrain periaqueductal gray area. Second, filterable nocardiae might grow to be branching cylindrical tubules such as that of mycelial bacteria in the presence of erythrocyte lysates.

Comparative American and Japanese tobacco smoke uptake parameters after overnight tobacco deprivation.

American and Japanese overnight deprived tobacco smokers were compared with respect to expired CO, plasma nicotine and cotinine, and red cell carboxyhemoglobin. The participants were 51 of 59 American and 55 of 86 Japanese cigarette smokers of mixed gender who met similar strict criteria. Female and male American tobacco smokers were similar in mean age, number of cigarettes smoked per day, machine-rated nicotine and tar yield per cigarette and per 24 h plasma cotinine, calculated previous 24 h nicotine dose, and exhaled CO. Only mean plasma nicotine levels were significantly higher in American females. American and Japanese female smokers had similar tobacco uptake parameters. American and Japanese male smokers differed; the latter had higher plasma nicotine and lower cotinine levels as well as calculated 24 h dose of nicotine and lower exhaled CO. Japanese females and males were similar in all tobacco smoke uptake parameters. When the two racial groups were compared, irrespective of gender, the only statistically significant differences were lower mean exhaled CO levels and percent COHb in the Japanese. It is concluded that Japanese males inhale cigarettes in moderation compared to Americans. The results are discussed in relation to known ethnic, social, and genetic differences in CYP2A6 gene polymorphism.