Effects of BCG and C. parvum treatment on human melanoma xenografts.

CBA mice rendered immunodeficient by thymectomy, potentially lethal gamma-irradiation and reconstitution with bone marrow cells were used to grow a wide variety of human tumours as subcutaneous implants. Samples of human melanoma obtained at surgery were successfully passaged by transplantation and produced rapidly growing tumours, some of which metastasized to lung, lymph nodes and the para-aortic node; this system was used as a model for the study of immunotherapy of melanoma. Preliminary results show that intratumour injections of C.

Reverse transcriptase and thymidine kinase as markers for tumorigenicity and viral contamination of cells.

Continuous monitoring of enzymes, particularly those involved in nucleic acid synthesis could be a useful means of detecting infections and abnormalities in cells in culture. Model systems using mouse (3T3), human (MRC-5) and chick embryo cells infected with RNA tumour viruses were studied. Reverse transcriptase activities were determined by the incorporation of (3H) nucleotides into synthetic primer-templates or into complementary DNA of endogenous RNA and characterised by their specificity for primer-templates dT12-18.

Some properties of the polysaccharide from cell cultures infected with TRIC agent (Chlamydia trachomatis).

The polysaccharide, elaborated in trachoma-inclusion conjunctivitis (TRIC) agent inclusions, was isolated from baby hamster kidney (BHK) cells grown and infected in suspension cultures. It was characterized by physical, chemical and enzymic methods as a glycogen with an average chain length of 14 to 16 glucose units.