NEW DISCOVERIES

Auckland Star, Volume LXXIII, Issue 199, 24 August 1942, Page 2

NEW DISCOVERIES

CHECK TO BACTERIA

CONQUEST OF DISEASE

(By N. T. CLARE, M.Sc.)

Many races of pathogenic bacteria have now been stripped of much of their power to destroy human lives, thanks to the discoveries of the biochemists, who have given us such valuable drugs as the sulphanilamides. Blood poisoning, pneumonia, venereal diseases, and even the dread meningitis, are losing much of their power to maim and destroy, as science forges new weapons to be used against them. The scientific development of new drugs is briefly reviewed in this, the latest release of the New Zealand Association of Scientific Workers.

Ever since Pasteur demonstrated that many diseases are caused by the presence of bacteria in various parts of the body, scientists have constantly sought chemicals which could be applied to appropriate places to kill such bacteria. Many substances are sufficiently poisonous to bacteria for this purpose, but there are remarkably few which do not also affect the delicate living cells of the blood and tissues.

Safeguarding the Patient

Obviously it is useless to kill the bacteria which produce an illness if in doing so the patient is also going to be seriously affected by the cure. Therefore, of the countless numbers of bactericidal substances with which chemists can provide medical workers, the few safe but efficient ones must be carefully sorted out.

The study of such chemicals, the way in which they work, and their effects on animals and human beings, constitutes a large part of the science of "chemotherapy."

No advance in this science has been more rapidly productive of results than the successful use in recent years of the drug sulphanilamide and its related compounds.

Years of careful research were required to produce this drug in a safe but effective form, to learn just how much could be used without other effects appearing, and how much was required for each of the various diseases against which it is used. But once its proper use was understood the virtues of this substance in conditions such as pneumonia, venereal diseases, meningitis, and a host of minor ailments, made it an essential weapon in the hands of every trained enemy of bacteria.

Researches on sulpbanilamide soon led to the introduction of many closely related substances, each with its own particular advantages and peculiarities, each adding something new to the store of medical knowledge. Two, sulphapyridine (M and B 693) and sulphathiazole, rank with sulphanilamide in importance, but each has some feature which makes it first choice for particular diseases. None Is Perfect Yet despite the great benefit which these drugs confer on medical practice, none is perfect. All in some degree have effects on the human body unless administered with skill and care. Mostly these effects are minor in relation to the good results, but there are still a small number of people in whom sulphanilamide drugs quickly produce uncomfortable skin effects. A doctor is, however, quick to note these, and guard against them.

Recently cables from America announced the discovery of a new sulphanilamide type of drug, gramicidin, of great potency which was said "to have been obtained from the soil." To research workers in New Zealand it looked just like another of those startling stories of great scientific discoveries that are never heard of again; specially the idea of prepared from the soil looked like a journalist's distortion similar to that which reported a famous English scientist to have said the moon was made of broken glass.

Shortly afterwards, however, the sensational newspaper announcement was explained by a series of papers in a leading American biochemical journal. These described the discovery of two substances, apparently proteins, which were obtained from cultures of harmless bacteria which normally occur in soil.

Injection experiments with animals showed that these two new chemicals were extremely powerful in killing certain classes of bacteria. Note, however, that the substances are not sulphanilamides, nor are they obtained directly from soil as the cables inferred. Not Prepared From Soil Though their chemotherapeutic action may resemble that of sulphanilamides, they are proteins, and as like sulphanilamide as cheese is to sulphate of ammonia. And they are not prepared from soil, but from the dead bodies and waste matter of bacteria whose ancestors were carefully selected from the many types of bacteria which grow in soil.

Of the future of these two substances in medical science no more can yet be said. Few reports on their properties other than that of killing bacteria are yet available. Their high toxicity when injected into blood is a great disadvantage, but they are apparently harmless when injected under the skin, or used on the surface. Already they have been shown to be effective in some animal diseases, but mostly their application is very much in the experimental stage. Also difficulties in preparing large amounts of them may hinder their wide use.

These new chemicals—the more important has been called "gramicidin"—may quietly drop out of the scientific literature; on the other hand they may herald a new onslaught in the war on bacteria which infect the human body.