Immunopathological studies on the cutaneous lesions in sarcoidosis

We examined the immunohistology of the cutaneous granulomas in sarcoidosis. By direct immunofluorescence immunoglobulin deposits were found in the skin lesions of 5 to 8 patients. These consisted of IgM within blood vessel wall (5 patients), IgM at the epidermal-dermal junction (2 patients) and IgG within and around the granuloma (2 patients). A fibrin network was present within the granulomas. Biopsy of a Kveim test site but not of uninvolved skin or of an erythema nodosum lesion showed similar immunofluorescence findings. Sheep erythrocytes sensitized with IgG antibody adhered to epithelioid cells within the granuloma indicating the presence of surface Fc receptors. At the periphery of the granulomas were B-lymphocytes. These findings are similar to those described in nodal and pulmonary sarcoid granulomas, and suggest that humoral antibodies may be important in the pathogenesis of the sarcoid granuloma.     

Subchronic Toxicity of Ingested 1,3-Dichloropropene in Rats and Mice

Male and female Fischer 344 rats and B6C3F1 mice (10/sex/dosegroup) were given 0, 5, 15, 50, or 100 mg/kg/day (rats) or 0,15, 50, 100, or 175 (mice) mg/kg/day racemic 1,3-dichloropropene(1,3-D), respectively, via their diets for 13 weeks. Satellitegroups of rats (recovery = 10 rats/sex/group) ingesting 0 or100 mg/kg/day 1,3-D were provided control feed for an additional4 weeks to examine recovery. The test material was stabilizedin the feed by microencapsulation in a starch/sucrose matrix(80/20). The body weights of male and female rats Ingesting>5 and >15 mg/kg/day, respectively, and of all treatmentgroups of mice were decreased relative to controls. The terminalbody weights of high dose group rats and mice were decreasedapproximately 13–16%. A number of changes in serum biochemicalparameters and decreases in organ weights accompanied the depressedbody weights of these animals. Histologically, the only treatment-relatedchange observed was a slight degree of basal cell hyperplasiaand hyperkeratosis in the nonglandular portion of the stomachsof a majority of male and female rats ingesting >15 mg/kg/day.After the 4-week recovery period, most treatment-related changeswere noted to be reversible in nature. No treatment-relatedhistopathological changes were observed in the tissues of treatedmice. Based upon relatively slight depressions in body weightsat the lowest dosages tested, the no-observed-adverse-effectlevels for male rats and both sexes of mice were determinedto be 5 mg/kg/day and 15 mg/kg/day, respectively. A no-observed-effectlevel of 5 mg/kg/day was established for female rats.