TOP MEDICAL DISCOVERIES OF THE 20th CENTURY

1. The Genetic Code - DNA James Watson and Francis Crick unravelled the mystery of the human genetic coding called DNA in 1953. They discovered how the genes for recreating life were arranged in a double helix and the sequence which creates the proteins which give us our genetic traits.

In the 50 year span since the DNA sequence was recognized scientists working on the genome have at last unraveled the human gene sequence and now gene therapy is the new frontier of medicine. 

2. Mass Immunization - VACCINES After 1952 mass immunization programs using the Salk vaccine for poliomyelitis.

Other newly developed vaccines (Tuberculosis, Measles, Mumps, and Small Pox- late 1800’s) were used throughout the western world to reduce deaths from disease, in many cases totally eradicating such problems.

FIGURE 1. Reported rates per 100,000 persons of poliomyelitis and of death from poliomyetitis, United States, 1932 to 1989. (IPV = inactivated polio vaccine; OPV = oral polio vaccine.)

3. Cancer Research Intense research in the 1940s led to a greater understanding of cancer and its aggressive nature. Experts began to realize that there was a body of evidence suggesting exposure to certain environmental factors such as smoking, poor diet, heavy metal absorption and exposure to radiation were strong causes of the disease.

Now early detection and an understanding of familial susceptibility, combined with radical surgery, radiotherapy and, or chemotherapy can give remission in many cases.

4. Aspirin - Analgesics At the start of the century in 1900 the Austrian, Felix Hoffman discovered that the bark of the willow tree yielded Salicylic Acid. When prepared this is called Aspirin.

The pain relief tablet first produced by Bayer was revolutionary at the time. Despite many discoveries of other pain relief tablets it is still one of the most widely used drugs on earth. More recently it has been used in the treatment of arthritis using aspirin injections at the site of pain. Scientists continue to seek new uses for it. It was recently realized that its potential had been underestimated and it was a very important drug of the 20th century. 

In 1794, English physicians Richard Pearson and Thomas Beddoes used ether in the treatment of phthisis (TB), catarrhal fever (infection).   These treatments were performed at the Beddoes' Pneumatic Institute.   A little later in 1805, American physicians used ether to treat pulmonary inflammation. The discovery and use of chloroform revolutionized surgery in the first half of the nineteenth century. As an alternative form of anaesthetic to ether, the medical fraternity debated the comparative differences between these two agents for most of the 1800's. Nitrous oxide, N2O, is a colorless, almost odorless gas, that was first discovered in 1793 by the English scientist and clergyman Joseph Priestley (who was also famous for being the first to isolate other important gases such as oxygen, carbon monoxide, carbon dioxide, ammonia, and sulfur dioxide). Later a scientist named Davy used it and watched the amusing effects on people who inhaled it, coined the term 'laughing gas'! Davy even noted the anaesthetic effects of the gas:

5. Blood Groups And Transfusions At last in 1901 an understanding of blood group analysis and improved methods of storage led to the start of blood transfusions. Many, many lives have been saved with blood transfusions either after accident, during operations, after illness or through blood disorders.

INSULIN Insulin should have been named protein of the 20th century. It was one of the first proteins to be crystallised in pure form, in 1926. It was the first protein to be fully sequenced in 1955, the first protein to be chemically synthesized in 1958 – though in insufficient quantities to be produced commercially – and the first human protein to be manufactured by way of biotechnology in 1979. 7.INSULIN-   The pancreas cells make insulin for the body.  Insulin is needed to get glucose sugar into cells for energy. Some Diabetics don't have pancreas cells that make insulin for them, so then they can get insulin from an animal or have someone make human insulin by using human DNA.  First they put DNA coding for insulin into bacteria DNA, next they feed the bacteria cells to make insulin from special DNA, then they remove the insulin and give it to a diabetic person.

FREDERIC BANTING Insulin is made in special cells in the pancreas called beta cells.  Insulin helps you to keep alive and gives you energy by letting all the body cells use glucose (sugar).  People who don't make their own insulin have TYPE I Diabetes.  Diabetic people need insulin shots every day.

6. Antibiotics The Scottish Scientist Sir Alexander Fleming discovered the antibiotic penicillin accidentally in 1928. He was culturing bacteria and he went on holiday. In his haste to go away he left the Petri dish lid ajar and when he returned a mould had killed the bacteria in the same dish. It took 10 years for scientists to extract the penicillin from the fungus. The wonder drug was still rare at the start of World War II, but where it was administered (to forces personnel) it saved lives. Despite problems now with over administration of antibiotics to people and animals, it is still one of the finest medical drug discoveries of the 20th century, even though a small minority are allergic to it.  

http://www.youtube.com/watch?v=CIkUtfJ0yYQ Penicillin Action and Penicillin Resistance