Teratomas

The most common nonmalignant etiology of SVCS is catheter-related thrombosis primarily owing to the increasing use of central access devices. Other causes include benign teratoma, tuberculosis, silicosis, and sarcoidosis. 

Most research into in vitro foreign protein production has been undertaken using cell suspensions. However, other forms of plant tissue culture such as hairy roots and shooty teratomas have also been tested in a number of studies (Table 2.1). The characteristics of different types of plant tissue culture and their utility for large-scale foreign protein production are outlined in the following sections. 

Shooty teratoma Nicotiana tabacum (tobacco) A. tumefaciens transformation of leaf explant, regenerated plants sexually crossed CaMV 35 S Murine Ig 0.28 mg g 1 dry weight (t) 3.2mgL 1(t) 17... 

Shooty teratomas are differentiated cell cultures produced by transformation with certain strains of A. tumefaciens [107]. Thus far, there has been only one report of pharmaceutical protein production in teratoma cultures, and the levels of antibody were very low [106]. 

Testicular teratomas produced during a period of testicular growth stimulated by increased photoperiod (Guthrie 1971). 

Guthrie, J. 1971. Zinc induction of testicular teratomas in Japanese quail (Cotumix cotumix japonica) after photo-periodic stimulation of testis. Brit. Jour. Cancer 25 311-314. 

Manipulation of mouse teratoma cells. The cells from a teratocarcinoma may be dispersed and grown in tissue culture. These cells can be injected into an embryo (a), in which case the resulting animal is a chimera in which some cells come from the original parents and others arise from the cells injected into the blastocyst. 

The most convincing evidence for the importance of cytoplasm on nuclear development comes from studies on teratoma, a unique type of tumor found in many kinds of mammals. It is composed both of neoplastic cells, like other tumors, and of many kinds of differentiated cells. A typical teratoma may include nerve, muscle, blood, and skin cells, and other differentiated cells all mixed together with undifferentiated neoplastic stem cells. Only the stem cells are neoplastic, producing more stem cells or more differentiated cells, usually both. In many ways the stem cells behave like... 

A subfertile man treated with human menopausal gonadotropin + human chorionic gonadotropin (hMG + hCG) developed a malignant teratoma of the testis however, in view of his history a cause-and-effect relation was dubious (43). 

Rubin SO. Malignant teratoma of testis in a subfertile man treated with HCG and HMG. A case report. Scand J Urol Nephrol 1973 7(l) 81-4. 

A rise in body mass index has been reported in young patients with teratomas treated with chemotherapy, still apparent 14 years after the end of treatment (317). 

Knutson JC, Poland A. 1980. Keratinization of mouse teratoma cell line XB produced by... 

Some teratoma cell lines isolated by method 1, e.g. the F9 cell line, have almost lost their capacity to differentiate. However, Strickland and Mahdavi (1978) have shown that differentation may be induced with retinoic acid at 10 9M. Again endoderm formation is detected by formation of plasminogen activator, a- foetoprotein, or by use of immunological markers (Adamson and Grover, 1983). 

J. G. Rheinwald and H. Green, Formation of a keratinizing epithelium in culture by a cloned cell line derived from a teratoma, Cell 6, 331 -343 (1975). 

Human cells, tissues, or organs implanted or transplanted in animals present a relatively strong and valuable tool, provided that immune rejection of the human material can be avoided. Immune-deficient animals like mice may well be used to develop organ-like structures (teratomas) from transplanted stem cells [13] or with combinations of human cells or human tissue (e.g., synoviocytes and cartilage [14], and activated mononuclear cells and transplanted skin [15]). 

Figure 13. Agrobacterium tumefaciens, the natural transformation system for plants. The bacterium contains a circular piece of DNA, the Ti-plasmid. The bacterium infects a dicotyledonous plant and transfers the T-DNA from the Ti-plasmid to the plant chromosomal DNA causing a tumor to form. The tumor is called a "crown gall". The gall, or teratoma, can be removed from the plant and placed into culture on medium without exogenous hormones.

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