 389  The mechanism by which by which spreads from one place in the body to ^any, has been the subject of intensive research у scientists for many years. What may be an answer to that question - and a suggestion as to how metasl might be inhibited - саше from the Institute for Cancer Research. Speculation on haw cancer spreads throughout the body has included possibilities that it does so through the migration of whole malignant cells fro the primary tumour mass, or through viruses that are released from dying caj cer cells. The report in the journal Science suggests a third possibility. This is that ca cer cells or viruses leak their genes - in the form of deoxyribonucleic acid, D> - into the bloodstream, and the DNA then travels to places -vhere it invades « mal cells and transforms them to malignant ones. To test this hypothesis scientists injected mice with DNA from polyoma ca cer virus and from a pneumococcal bacterium and compared the results. They found that DNA from tumor viruses was much more resistant body с fences than the bacterial DNA. The reason for this, they said, may have had i mething to do with the closed-ring form of the tumor-type DNA molecul They said results indicated that this DNA could still produce its cancerous i fects. Thus, the report said that "tumor-inducing DNA can be transported biologically active form from one part of the body to another." From The New York Tin MANIPULATING THE BRAIN Some persons were disturbed last week over a report of experiments which the behaviour of animals and people was influenced by electrical sti ted of selected regions of their brains. According to the report, weak currents made to flow through electrodes planted in the brains of monkeys and cats enabled scientists to "play" the mals like little electronic toys. They yawned, climbed, ran, turned, slept, and changed their emotional states from passivity to rage an vice versa, all electrical command. In one of the most spectacular experiments, a Spanish fighting bull was sti ped in full charge by a stimulus radioed to an electrode implanted in its bral which inhibited aggressiveness. People, too, have undergone such stimulation's in the course of diagnosis therapy for severe cases of epilepsy. Electrical stimulation's of certain regions, their brains have produced feelings of intense pleasure and of severe anxiety! loss of ability to think or express themselves a sudden increase in word outj® and profound feelings of friendliness. 11 389 |
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