The
discovery of penicillin was the most significant discovery of the 20th
century, because it led to the availability of antibiotics to cure infectious
diseases. The development of water treatment and sanitary sewers were equally
important in preventing infectious diseases.
Life
expectancy is an “average” death age of a population invented by the
statistician who drowned in a lake with a mean depth of 3 feet. Life expectancy
in the US is 76 for men and 81 for women. Because it includes all deaths, it is
not a “maximum” age and many healthy seniors in the US are living into their
90s. There are just as many seniors who have died in their 60s, plus newborns
and everybody in between. If you list everybody who died last year in the US
and average their age, you would have calculated “life expectancy” for that
year in the US.
A major
causes of death in the 18th and 19th centuries were
infectious diseases like small pox, cholera, typhus, yellow fever, diphtheria,
dysentery, malaria, hepatitis, tuberculosis and influenza. Bubonic plague
killed 200 million people in the 1300s.
Antibiotics
treat a long list of bacterial infections that used to result in death. The
improvement in the human lifespan is largely due to the introduction of
antibiotics in 1945.
Antibiotics
was discovered in 1928 by Alexander Fleming who
discovered the first antibiotic,
penicillin, but it took over a
decade before penicillin was introduced as a treatment for bacterial
infections.
The
Microscope was invented in the 1590s by two
Dutch spectacle makers, Zacharias Jansen and his father Hans started
experimenting with these lenses. They put several lenses in a tube and made a
very important discovery.
In 1653, Petrus Borellus [1]
wrote the first publication on the use of microscope in medicine. He described
100 observations and applications, including how to remove ingrowing eyelashes
that are invisible to the naked eye. In 1646, Athanasius Kircher [2] (or
“Kirchner, as it is often spelled), a
Jesuit priest, wrote that “a number of things might be discovered in the blood
of fever patients.” In 1658, in his Scrutinium Pestis, Kirchner [3]
described microscopic “worms” in plague victims which he suspected caused
the disease that
killed millions of people in Europe during the 17th century. Most likely, he
was viewing pus cells, or perhaps red blood cells, since he could not possibly
see the Bacillus pestis with
his 32-power microscope. Another early microscopist was Joseph Campini of
Bologna. His microscope was the first that was depicted in clinical use
in medicine.
Clinical microscopy had a slow beginning; more than two
centuries passed before the value of microscopes began to be appreciated by
clinical and laboratory scientists. In 1800, Bichat (1771–1802), a young
pathologist, published a book in which, for the first time, morbid anatomic and
histopathologic changes of various organs of
the body were discussed and illustrated. Soon thereafter the microscope became
an indispensable laboratory tool at medical schools all around the world.
Microscopes
with higher magnification were developed in the 1700s from 50x to 270x and
later in the 1800s to 500x. Now good magnification is 1000x and 1500x.
Norb
Leahy, Dunwoody GA Tea Party Leader
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