Radiation therapy of nasopharyngeal carcinoma

Carcinoma of the nasopharynx is one of the most frequent malignant tumors in the southern parts of China. A total of 3 263 cases treated with irradiation in the course of the thirty years since the Liberation have been analysed retrospectively. The 5-year survival rate has risen from 27.7 per cent for cases treated during 1955 to 1960 to 54 per cent for those treated in 1973. The technique of irradiation is described, emphasizing the importance of suitable techniques for the treatment of the cervical lymph nodes. The value of elective irradiation of cervical regions not involved clinically is elucidated. Finally, the causes of failure of treatment are discussed.

Arrangement of glucose residues in the lipid-linked oligosaccharide precursor of asparaginyl oligosaccharides

The lipid-linked oligosaccharide synthesized in vitro, in the presence of 1.0 microM UDP-[3H]Glc, GDP-[14C]Man, and UDP-GlcNAc has been isolated and the structure of the oligosaccharide has been analyzed. The oligosaccharide contains 2 N-acetylglucosamine, 9 mannose, and 3 glucose residues. The N-acetylglucosamine residues are located at the reducing terminus. The 3 glucose residues are arranged in a linear order at one of the nonreducing termini in the sequence Glc 1,2--Glc 1,3--Glc--(Man)9 (GlcNAc)2. The structural analysis was made possible largely by the availability of glucosidase preparations of fungal anad microsomal origin which remove glucose residues from the oligosaccharide without releasing mannose residues.

Effects of UDP-glucose addition on the synthesis of mannosyl lipid-linked oligosaccharides by cell-free fibroblast preparations

The pattern of mannosyl lipid-linked oligosaccharides synthesized by cell-free enzyme preparations from cultured fibroblasts is altered substantially when 0.2 muM UDP-glucose is added to the incubation medium. Inclusion of UDP-glucose results in the appearance of a new labeled oligosaccharide, which is 1 or 2 glycose units larger than the lipid-linked oligosaccharide synthesized in the presence of only GDP-mannose (2 muM) and UDP-N-acetylglucosamine (20 muM). Label from UDP-[3H]glucose is incorporated into the same larger oligosaccharide size class. The results can be explained most easily by assuming that the new mannosyl lipid-linked oligosaccharide contains 1 or 2 glucose residues in addition to 5 to 6 mannose residues. The results are compatible with the recent finding by Spiro et al. (Spiro, M.J., Spiro, R.G., and Bhoyroo, V.D. (1976) Fed Proc. 35, 1375; Spiro M.J. Spiro, R.G., and Bhoyroo, V.D. (1976) J. Biol. Chem. 251, 6400-6408; Spiro, R.G., and Spiro, M.J. AND Bhoyroo, V.D. (1976) J. Biol. Chem. 251, 6409-6419; Spiro, M.J., Spiro R.G., and Bhoyroo, V.D. (1976) J. Biol. Chem. 251, 6420-6425) that naturally occurring mannosyl lipid-linked oligosaccharides contain glucose. In addition to being incorporated into lipid oligosaccharides, glucose residues are also incorporated into endogenous glycoproteins. Incorporation of glucose into glycoproteins that give rise to pronase glycopeptides of the typical asparagine-linked size classes is almost completely dependent on the presence of GDP-mannose.

Renal pelvic tumour associated with analgesic abuse

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