Cancer study

The mechanism by which by which spreads from one place in the body to many, 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 metastasis might be inhibited - came from the Institute for Cancer Research.

Speculation on haw cancer spreads throughout the body has included the possibilities that it does so through the migration of whole malignant cells from the primary tumour mass, or through viruses that are released from dying cancer cells.

The report in the journal Science suggests a third possibility. This is that cancer cells or viruses leak their genes - in the form of deoxyribonucleic acid, DNA - into the bloodstream, and the DNA then travels to places where it invades normal cells and transforms them to malignant ones.

To test this hypothesis scientists injected mice with DNA from polyoma cancer virus and from a pneumococcal bacterium and compared the results.

They found that DNA from tumor viruses was much more resistant body defences than the bacterial DNA. The reason for this, they said, may have had something to do with the closed-ring form of the tumor-type DNA molecules. They said results indicated that this DNA could still produce its cancerous effects.

Thus, the report said that "tumor-inducing DNA can be transported in biologically active form from one part of the body to another."

From The New York Times manipulating the brain

Some persons were disturbed last week over a report of experiments in which the behaviour of animals and people was influenced by electrical stimulated of selected regions of their brains.

According to the report, weak currents made to flow through electrodes implanted in the brains of monkeys and cats enabled scientists to "play" the animals like little electronic toys. They yawned, climbed, ran, turned, slept, mated and changed their emotional states from passivity to rage an vice versa, all on electrical command.

In one of the most spectacular experiments, a Spanish fighting bull was stopped in fall charge by a stimulus radioed to an electrode implanted in its brain, which inhibited aggressiveness.

People, too, have undergone such stimulation's in the course of diagnosis and therapy for severe cases of epilepsy. Electrical stimulation's of certain regions of their brains have produced feelings of intense pleasure and of severe anxiety, a loss of ability to think or express themselves a sudden increase in word output and profound feelings of friendliness.

The scientists who reported these findings was Dr. Jose Delgado of Yale University's School of Medicine. In a lecture, Dr. Delgado discussed some aspects of this work that might worry persons outside this field of research.

He emphasized, first, that the implantation of electrodes in the brain ah the passage of weak currents through them neither hurts (brain tissue is insensitive) nor causes any functional damage.

Such studies, Dr. Delgado believes, may enable scientists to discover the "cerebral basis of anxiety, pleasure, aggression and other mental functions, which we could influence in their development and manifestation through electrical stimulation's, drugs, surgery and especially by means of more scientifically programmed education".

Dr. Delgado believes that control of human behaviour on a large scale would not work because the effect of a stimulus can be changed or even overridden by the subject's own desires, emotions, etc. This has been shown in experiments on both animals and people. For example, monkeys in which aggressive behaviour was electrically stimulated did not just attack any other member of the colony, but made "intelligent" attacks only on rivals, sparing their "friends".

Dr. Delgado thinks it will be necessary to develop new theories and concepts to explain the biological bases of social and anti-social behaviour. These, he said, "for the first time in history can be explored in the conscious brain".