Dalmatian dogs may develop a neurona1 or generalized ceroid-lipofuscinosis (NCL) which strongly resembles that seen in English setters, especially as to the ultrastructural changes and ubiquity of the stored lipopigments and the retina1 pathology, while differing clinically from the disorder of English setters in that the disease has a longer course of up to 5 or 6 yr. Clinical onset is at about age 6 months; however, an unequivocal morphological diagnosis is posible between the 4th and 5th month of life in biopsied skin. Detailed data of additional investigations are in progress and are awaiting later publication.Thus, NCL in the Dalmatian dog, though not yet as thoroughly investigated as NCL of the English setter, may provide another useful model for human NCL. Whether future biochemical studies will provide further similarities or even dissimilarities to NCL in English setters and in man remains to be seen. The cause of NCL in the canine and in humans is hornozygosity of an autosomal recessive gene; however, the pathogenesis of the NCL in Dalmatian dogs is unknown as it is in English setters, other canine species, non-canine species, and in humans.
Six-month-old Fischer rats (F344) were given the carcinogen methylnitrosourea in their drinking water. Of the induced brain tumors, four were established in culture and propagated as 78FR-G-219 (pleomorphic glioma), 78FR-G-299 (astrocytoma), 78FR-G-284 and 78FR-G-344 (mixed glioma) permanent lines. All cell lines produced S-100 protein and grew as tumors when inoculated s.c. or i.c. in syngeneic hosts. A comparative study of the antigenicity of these lines at different passage levels was carried out using native and chemically modified cells. Syngeneic rats were immunized with cells conjugated with dimethylsulfate and trinitrobenzene sulfonic acid. The immune response was characterized and quantified by an indirect immunofluorescence method and by a complement-dependent microcytotoxicity test. Chemical modification of the tumor cells enhanced antigenicity of the treated cells. The best results were attained with trinitrobenzene sulfonic-acid-treated cells and constituted a two-fold increase in the cytotoxicity index. Cytotoxicity values varied in the different cell lines. Antisera raised with trinitrobenzene sulfonic-acid-modified cells of all lines cross-reacted with cells of all lines. Cytotoxicity values were insignificantly reduced by absorbing the antisera with a variety of syngeneic tissues. Antisera raised against native syngeneic brain cells showed virtually no cytotoxicity for glioma cells. Antisera raised against syngeneic brain cells treated with trinitrobenzene sulfonic acid, however, were slightly cytotoxic for normal brain cells and glioma cells as well. The results of the present studies show that antigenicity of glioma cells can be definitely raised with trinitrobenzene sulfonic acid treatment. Furthermore, it would seem that haptenization of glioma-associated antigens may be a promising approach ot the study of glioma-host interactions.
Purified McAbs (14AC1) of IgG2a isotype raised against an experimental rat glioma (79FR-G-41) were labeled with Na131I and used for in vivo imaging of glioma grafts by external body scintigraphy. Normal mouse 131I-IgG was applied as control for non-specific uptake of proteins in the tumor. Nude mice bearing glioma grafts were injected i.v. with 15 micrograms of the 131I-McAb or 131I-IgG with an activity of approximately 150 microCi. Scans obtained 30 min, 24, 48, 72, and 96 h after injecting the intact 131I-14AC1 antibody demonstrated enrichment of radioactivity in the tumors. The tumors were clearly visible 48 h after injection of 131I-labeled antibody. The time course experiments showed that the uptake of 131I-14AC1 antibody in the glioma grafts was the result of specific antigen binding. Intact antibody provided adequate tumor visualization in the scintigrams without background subtraction. Therefore, this technique appears promising for in vivo tumor detection and may offer the possibility of improvement in the evaluation of diagnostic and therapeutic approaches to human gliomas.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.