Our 86 cases of neuronai ceroid-lipofuscinosis (NCL) included 7 children with the infantile variant, 28 with the late infantile variant, and 51 with the juvenile variant. Thirty-one cases were drawn from a NCL registry and were not evaluated personally by the authors. Another 30 cases from the registry were not inciuded because of inadequate data. The clinical course was subacute in most children with the infantile and late infantile variants and chronic in the juvenile variant. Sixteen of 86 cases (19%) were considered to be atypical clinically [3/7 (43%) with the infantile variant, 3/28 (11%) with the late infantile variant, and 10/51 (20%) with the juvenile variant].Clinical variability among and between families was most striking in the juvenile variant. Pathological investigations of skin, buffy coat and/or brain showed atypical and/or more than one type of cytoplasmic inclusions in 10/50 (20%) of late infantile and juvenile variants. Al1 of the children with the infantile variant had granular, osmiophilic profile in tissues. Biochemicai studies on the glycoproteins of cultured fibroblasts in three cases of juvenile NCL showed that there was a higher proportion of one size class of N-linked oligosaccharides and a higher proportion of mannosecontaining glycoproteins in NCL than in control cells. This supports previous lectin histochemical studies of glycoconjugates in skin of juvenile NCL [Wisniewski and Szumanska, 19861 and suggests that there may be defects in the processing of N-linked oligosaccharides in the glycoproteins of juvenile NCL.

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The extracellular anionic polysaccharide isolated from cultures of a unicellular red alga, Porphyridium cruentum, contains a small amount of protein after extensive purification. The polysaccharide and protein are recovered in the same fraction after isopycnic CsCl-density-gradient centrifugation in 4M-guanidinium chloride, under conditions designed to separate proteins from polysaccharide. The peptide portion of the protein-polysaccharide is released from the polysaccharide by alkali under conditions for beta-elimination. The released peptide is non-diffusible, but in can be separated from the polysaccharide by precipitation of the polysaccharide as the cetylpyridinium complex. Under conditions for beta-elimination of certain O-glycosidic carbohydrate-protein linkages, selective destruction of serine and threonine occurs. The addition of a reducing agent to the alkali mixture produces a selective increase in alanine and alpha-aminobutyric acid. Addition of a tritiated reducing agent to the alkali mixture produces radioactive alanine and alpha-aminobutyric acid, and xylitol as the only sugar alcohol. Similar results are obtained from glycopeptides isolated from partial acid hydrolysates. A macromolecular structure of the protein-polysaccharide is suggested by a comparison of the intrinsic viscosity of material before and after treatment with alkali and proteolytic enzymes.

Surface macromolecules shed into culture medium by radioiodinated human melanoma cells were fractionated on Sepharose 6B and by sequential lectin-affinity chromatography. Radioactivity associated with melanoma-associated antigens (MAAs) was assayed by indirect immunoprecipitation with anti-melanoma serum. Two MAAs were separated and highly purified. Both antigens were single-chain glycoproteins expressed on many, but not all, melanoma cells but undetectable on normal melanocytes and a variety of unrelated normal, fetal, and malignant cells. One MAA, with a molecular mass of approximately 115 kd, eluted on Sepharose 6B in a lower molecular mass peak and had a high affinity for ricin lectin. The carbohydrate side chain of this antigen contained D-galactose. The other MAA, with a molecular mass of approximately 125 kd, eluted on Sepharose 6B in a peak of higher molecular mass and had a high affinity for wheat germ lectin. The carbohydrate side chain of this antigen contained sialic acid. Both antigens were highly purified. By sodium dodecyl sulfate-poly-acrylamide gel electrophoresis analysis, no contaminating proteins were present in the purified 115-kd MAA fraction, and only a single minor contaminant was present in the fraction containing the purified 125-kd MAA. These two antigens differed in their biochemical or immunological properties from other MAAs of similar size that have been previously described.

Melanoma-associated antigens (MAAs) recognized by murine monoclonal and rabbit polyclonal antibodies were compared. Two rabbit antimelanoma sera raised in our laboratory recognized five human cell-surface MAAs with approximate MWs of 75, 95, 120, 150, and 240 kd. These antigens were easily detected by SDS-PAGE of specific immunoprecipitates on a melanoma cell (HM31) which failed to reveal antigens reactive with the panel of murine monoclonal antibodies studied. By contrast, these five antigens could not be detected on another melanoma cell (SK-MEL-28), which was reactive with several of the murine monoclonals. These results suggest that the MAAs recognized by rabbit and murine antibodies are different and imply that the antigens which are immunogeneic in man may not necessarily be immunogeneic in mice.