The top medical advancements of the 20th century, many of which earned their discoverers Nobel Prizes, included treatments for previously incurable diseases that often stemmed from groundbreaking insights into the workings of the human body. New technologies also emerged that now allow people to defy nature when it comes to reproduction and family planning.
Antibiotics to the Rescue
London bacteriologist Alexander Fleming discovered penicillin in 1928 upon finding that mold had killed staphylococcus bacteria he'd been growing in a petri dish. In 1939, Oxford University scientists Howard Florey and Ernst Chain initiated experiments to purify penicillin, the first antibiotic, which made potentially fatal infections like blood poisoning and pneumonia treatable. Fleming, Florey and Chain shared the Nobel Prize in Physiology or Medicine in 1945. In 1952, that award went to microbiologist Selman Waksman, who along with his pupils at Rutgers University developed another antibiotic, streptomycin, the first cure for tuberculosis. Produced by soil microbes, streptomycin also proved effective against cholera, bubonic plague, typhoid fever and other illnesses.
To Bear or Not to Bear
In the 1940s, Syntex, a Mexican drug company, established itself with a synthetic version of the anti-inflammatory hormone cortisone that was hailed as a godsend for arthritis. That discovery paved the way for Syntex chemist Carl Djerassi to create norethisterone, an artificial variety of the pregnancy hormone progesterone capable of preventing ovulation. Norethisterone became the active ingredient in Enovid, the first birth control pill, approved by the Food and Drug Administration in 1960. Birth control gave women more control over their personal and professional lives, while in the 1970s, the advent of in vitro fertilization -- the fusing of sperm cells and eggs in test tubes -- gave infertile couples a new option for having children.
Help for Diabetics
Prior to the discovery of insulin in 1921, diabetes -- a condition in which the body fails to produce enough insulin to properly regulate blood sugar -- was fatal. Earlier scientists had determined that the pancreas produces insulin, but it was Nobel Prize winners Frederick Banting and John Macleod who first isolated the substance through experiments on dogs and cattle. Though not a cure, insulin supplementation enables diabetic patients to lead close to normal lives. In 1947, Carl and Gerty Cori won the Nobel Prize for discovering the processes by which the body converts glucose to energy, which led to additional treatments for diabetics.
Know Your ABOs
A blood transfusion was a potentially deadly proposition before 1901, when Karl Landsteiner identified four distinct blood types based on combinations of antigens and antibodies. He called the groups A, B, AB and O. Landsteiner, who received the Nobel Prize for his discovery, determined that mixing incompatible types of blood caused a life-threatening clumping of cells. His findings led to blood typing of patients and donor blood, and thus made transfusions safer.
Spotlight on Diet
The study of vitamins and their role in cellular health began in the 19th century and continued into the 1900s, with each discovery altering the medical approach to nutrition. One of the most important vitamin-related achievements belonged to Albert Szent-Gyorgyi, who received the Nobel Prize in 1937 for discovering Vitamin C, or ascorbic acid. A lack of Vitamin C was subsequently identified as the cause of scurvy, a common disease among sailors who were at sea without access to fresh produce.
Building Blocks of Life
While nucleic acids had already been discovered and shown to contain genetic information, James Watson and Francis Crick opened the floodgates of molecular biology in the 1950s when they described the structure of deoxyribonucleic acid, or DNA. Using X-rays, they determined that DNA molecules come in the shape of a double helix, which shed light on how genetic material is copied and transmitted. The medical implications of Watson and Crick's discovery include the potential for gene therapy, which entails manipulating DNA in order to treat disorders caused by missing or incomplete genes.