Browsing by Author "Kitinya, James Nyaga Nonga"

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    Carcinoembryonic antigen: a review of literature
    (University of Dar es Salaam, 1978) Kitinya, James Nyaga Nonga
    This study was undertaken through literature review on carcinoembryonic antigen. The study indicate that carcinoembryonic antigen is a glycoprotein that consists of one polipeptide chain which accounts for 20 50% weight. The carbohydrate. Protein bond is between asparagine and N-acetylglucosamine. Carbohydrate content is 40-60% by weight (and there is variation in sugar residues). It is a heterogenous molecule, this being due to variations in carbohydrate protein ratio and the proportion of individual amino acid and sugar residues. Sialic acid variation is frequent and gives rise to differences in the surface change of the molecule. Further review of literature revealed that carcinoembryonic antigen is a normal constituent of foetal gut in the first and second trimesters of pregnancy when its synthesis ceases. It is in the glycocalyx layer of the cell surface on the luminal aspect. It appears mainly in carcinomas of the gastrointestinal tract but also in a variety of other cancers especially bronchus and breast and in inflammatory conditions of the gastrointestinal tract and respiratory system. It is found also in the serum of the patients with these disorder. Review further show that it was discovered by Gold when he produced monospecific antiserum by injecting into rabbits tumour extracts of colon carcinomas then absorbed the antiserum with normal colon tissue extract. Review of literature also showed that Serum assays are mainly by radioimmunoassay methods. The main application of carcinoembryonic antigen assays is in the detection of residual tumour after resection as levels in serum promptly decline; and serial levels are useful in the follow up of patients as its reappearance proceeds clinical detection of tumour by at least three months.