Wednesday, May 2, 2007

Nobel Laureate: Christiaan Eijkman

 
 

The Nobel Prize in Physiology or Medicine 1929.



Christiaan Eijkman (1858-1930): "for his discovery of the antineuritic vitamin"



Christiaan Eijkman won the Nobel Prize in 1929 for his observations leading to the discovery of thiamine or vitamin B1. Deficiencies of thiamine cause beriberi, a disease that was widespread in Asia before the cause was discovered by Eijkman.

The story of Christiann Eijkman is well-known to most biochemistry students. Here's the story as recounted in the Nobel Prize presentation speech.
That the fruits of civilization are not solely beneficial is shown by, inter alia, the history of the art of medicine. Not a few illnesses and diseases follow close on the heels of, and are more or less directly caused by, civilization. This is the case with the widespread disease beriberi, first described more than 1,300 years ago from that ancient seat of civilization, China. In modern times, however, it was not until towards the end of the 17th and the beginning of the 18th century that the disease attracted more general attention. Subsequently it has, on different occasions and with varying degrees of violence, made its appearance in all five continents, but more particularly its haunts have been in Eastern and South-Eastern Asia. At times the disease has been a serious scourge there. Thus in 1871 and 1879, Tokio was visited by widespread epidemics, and during the Russo-Japanese War it is said that not less than one-sixth of the Japanese army was struck down.

Beriberi shows itself in paralysis accompanied by disturbances in the sensibility and atrophy of the muscles, besides symptoms from the heart and blood vessels, inter alia, tiredness and oedema. Decided lesions have been shown in the peripheral nerves which seem to explain the manifestations of the disease. Mortality has varied considerably, from one or two per cent to 80 per cent in certain epidemics.

A number of circumstances indicated a connection between food and beriberi: for example, it was suggested that the cause might be traced to bad rice or insufficiency in the food of proteins or fat.

The severe ravages of beriberi in the Dutch Indies led the Dutch Government to appoint a special commission to study the disease on the spot. At the time, bacteriology was in its hey-day, and it was then but natural that bacteria should be sought as the cause of the disease, and indeed it was thought that success had been attained. The researches were continued in Java by one of the commission's coadjutors, the Dutch doctor Christiaan Eijkman. As has so often been the case during the development of science, a chance observation proved to be of decisive importance. Eijkman observed a peculiar sickness among the hens belonging to the laboratory. They were attacked by an upward-moving paralysis, they began to walk unsteadily, found difficulty in perching, and later lay down on their sides. The issue of the disease was fatal unless they were specially treated. It has been said that the secret of success is to be prepared for one's opportunity when it presents itself, and indubitably Eijkman was prepared in an eminent degree. With his attention focussed on beriberi, he immediately found a striking similarity between that disease and the sickness that had attacked the hens. He also observed changes in numerous nerves similar to those met with in the case of beriberi. In common with beriberi, this ailment of the hens was to be described as a polyneuritis. In vain, however, did Eijkman try to establish micro-organisms as the cause of the disease.

On the other hand, he succeeded in establishing the fact that the condition of the hens was connected with a change in their food, in that for some time before they were attacked they had been given boiled polished rice instead of the usual raw husked rice. Direct experiments proved incontestably that the polyneuritis of the hens was caused by the consumption of rice that by so-called «polishing» had been deprived of the outer husk. Eijkman found that the same disease presented itself when the hens were fed exclusively on a number of other starch-rich products, such as sago and tapioca. He also proved that the disease could be checked by the addition to the food of rice bran, that is to say, the parts of the rice that had been removed by polishing, and he found that the protective constituent of the bran was soluble in water and alcohol.

Eijkman's work led Vorderman to carry out investigations on prisoners in the Dutch Indies (where the prisoner's food was prepared in different ways according to the varying customs of the inhabitants), with a view to discovering whether beriberi in man was connected with the nature of the rice food they consumed. It proved that in the prisons where the inmates were fed on polished rice, beriberi was about 300 times as prevalent as in the prisons where unpolished rice was used.

When making investigations to explain the results reached, Eijkman considered that protein or salt hunger could not be the cause of the disease. But he indicated that the protective property of the rice bran might possibly be connected with the introduction of some particular protein or some special salt. At the time it might have been readily imagined that the polyneuritis in the hens and beriberi were due to some poison, and Eijkman set this up as a working hypothesis, though his attempts to establish the poison were in vain. In his view, however, such a poison was formed, but it was rendered innocuous by the protective substance in the bran. It was only Eijkman's successor in Java, Grijns, who made it clear that the substance in question was used directly in the body, and that our usual food, in addition to the previously known constituents, must contain certain other substances, if health is to be preserved. Funk introduced the designation vitamins for these substances, and since then the particular substance that serves as a protection against polyneuritis has been called the «antineuritic» vitamin.

It might have been expected that Eijkman's discovery would lead to an immediate and decided decline in beriberi - perhaps to the disappearance of the disease. But this was by no means the case, and not even in the Dutch Indies, where Eijkman and Grijns had worked, were the results particularly brilliant. The reasons for this were several: the reluctance of the inhabitants to substitute the less appetizing unpolished for polished rice, the opinion that polyneuritis in birds was not a similar condition to beriberi in man, and an inadequate appreciation of Eijkman's work. As a result of numerous experiments by different investigators on animals and human beings, who offered themselves for experimental work, it has gradually become clear that beriberi is a disease for the appearance of which lack of the vitamin found in rice bran - but also other circumstances - is of decisive importance. These experiences, in addition to successful experiments made in various places on the basis of Eijkman's observations, especially in British India, have gradually led to a general adoption of Eijkman's views. The successful attempts to combat beriberi which are now proceeding are the fruits of Eijkman's labours.

It was the analysis of the nature of the food used in cases of polyneuritis in hens that led Eijkman to his discovery. As a rule, analysis and synthesis complete each other, and indeed the employment of both these avenues of approach has been of decisive importance also for the development of the science of vitamins.

No comments:

Post a Comment