8 research outputs found
Study on the Pathogenesis of Foreign Body Granulomatous Inflammation in the Livers of Sprague-Dawley Rats
Focal granulomatous inflammation developed in the livers of five 10-week-old male
Sprague-Dawley rats. The characteristic features of this lesion were the
presence of foreign body multinucleated giant cells engulfing calcium deposits
and site-specific development in a fissure formed in a sub-lobation in the left
lobe or interlobar fissure of the medial lobe of the liver. To clarify the
pathogenesis of this lesion, rat livers showing abnormal sub-lobation or lobar
atrophy, rat livers in an acute dermal toxicity study and guinea pig livers in a
skin sensitization test were also examined histologically. Consequently, the
present lesion was considered to be a reactive change against calcium that was
dystrophically deposited in the area of hepatocellular necrosis due to delayed
circulatory disturbance caused by external pressure or extension force.
Granulomatous lesions like in the present cases should be differentiated from
those caused by evident exogenous pathogens such as chemicals or
microorganisms
Improved fixation of the whole bodies of fish by a double-fixation method with formalin solution and Bouin’s fluid or Davidson’s fluid
Safety evaluation of arabinase (arabinan endo-1,5-α-L-arabinanase) from Aspergillus tubingensis
Arabinase is an enzyme recognized for its ability to degrade arabinan, a plant cell wall constituent. It has been applied in the food industry most commonly for juice processing. One commercial source of arabinase is Aspergillus tubingensis (A. tubingensis), a black Aspergillus species. Given the intended use in food for human consumption, and noting its potential presence at trace levels in finished products, a series of safety studies including in vitro Ames and chromosome aberration assays, in vivo mammalian erythrocyte micronucleus and alkaline comet assays, and a 90-day rat oral toxicity study were conducted. No test article-related mutagenic activity was observed in the Ames assay. Although positive activity was observed in the chromosome aberration assay, this was not replicated in the in vivo genotoxicity assays including in preabsorptive cells. In the subchronic toxicity study, no test article-related adverse effects were observed following oral administration of arabinase at doses of 15.3, 153, or 1,530 mg total organic solids (TOS)/kg body weight/day to Sprague Dawley rats. The no-observed-adverse-effect level was considered to be the highest dose tested (1,530 mg TOS/kg body weight/day). The results of the genotoxicity studies and the subchronic toxicity study support the safe use of arabinase from A. tubingensis in food production