Transcript Discoveries - Mr. Lesiuk

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.
7.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.
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