Page No 2

19th-Century Medicine In the 19th century great advances occurred
in diagnosis and treatment of disease and in surgical methods.
European researchers established the sciences of embryology and
histology and the central concept of the cell as the seat of disease.
British scientist Charles Darwin advanced his theory of evolution.
Austrian biologist Gregor Johann Mendel laid out the basis of classical
genetics. Studies of fermentation by French chemist and
microbiologist Louis Pasteur revived interest in the contagion theory
of disease. Pasteur and German physician and bacteriologist Robert
Koch founded the field of bacteriology, considered the greatest single
advance in the history of medicine; many bacterial diseases became
preventable or controllable. Bacteriology allowed important
discoveries, including the role of white blood cells in destroying
microbes, the way in which bacteria are carried, and the necessity of
sterilization to prevent wound infection (see Antiseptics).
Other advances during this time took place in physiology
(including understanding of various glands and the nervous system),
organic chemistry and metabolism, optics and ophthalmology, and
psychology.
The X ray was discovered by German physicist Wilhelm Conrad
Roentgen; French physicists Pierre and Marie Curie discovered radium.
American physicians developed the field of gynecology and identified
mosquitoes as carriers of yellow fever.

20th-Century Medicine The most important medical finding of the 20th
century was the discovery by American biologist James Dewey Watson and
English physicist Francis Harry Compton Crick of the structure of the
genetic material, deoxyribonucleic acid, or DNA (see Nucleic Acids).
By 1970 the first gene had been synthesized; by the mid-1980s genetic
techniques were being used medically, and genetic engineering was
producing large quantities of pure human substances such as hormones and
interferon.
Surgery advanced with the development of operating microscopes
and other techniques that allow delicate procedures such as reattachment
of severed limbs. Medical milestones were reached with the successful
transplantation of organs and the development of the artificial heart and
kidney.  Plastic replacements for joints relieved some patients from crippling
arthritis, and lasers were developed for medical use, especially in eye
surgery.
Many infectious diseases have been conquered in the 20th century by
improved sanitation, antibiotics, and vaccines. Especially important were
the developments of the sulfonamide antibiotics and penicillin, which
immediately saved many lives in World War II (1939-1945).
Streptomycin, another drug, was used to defeat tuberculosis. Vaccines are
widely used against viral diseases, including poliomyelitis, diphtheria, tetanus,
yellow fever, measles, mumps, rubella (German measles), hepatitis B,
influenza, herpes simplex, and chicken pox.
Vaccine production was aided by new techniques such as tissue culture
production and genetic engineering. In the latter part of the 20th century
many microorganisms became resistant to antibiotics, and new diseases
emerged, such as Legionnaires' disease and acquired immune deficiency
syndrome (AIDS).
In the 20th century the brain was carefully explored. Using chemical dyes
and sophisticated imaging devices, scientists discovered the specific parts of
the brain that control hearing, speech, and movement of the limbs; they
showed that the right and left halves of the brain were functionally different.
The discovery of the chemical/electrical method of nerve impulse transmission
was an important finding, as were the complex way in which the brain
regulates body function by hormones and the complex connection between
emotions and biochemistry. Treatments became available for neurological
diseases such as epilepsy and Parkinson's disease.
Scientific insight into the workings of the immune system and the structure
of antibody molecules has allowed better treatment of immune disorders, even
temporary disabling of the immune system to prevent rejection of transplanted
organs (see Transplantation, Medical). One form of antibody molecule proved
to be associated with allergy, now viewed as an immune system disorder.
The typing of blood by immune specificity has made transfusion safe and
widely applicable (see Blood Type; Blood Transfusion).
In recent years, new and better methods of seeing inside the human body have
revolutionized medical diagnosis. The computerized axial tomography (CAT)
scanner is a computer-assisted X-ray device (see X Ray; Radiology).
Nuclear magnetic resonance imaging employs radio waves to identify
molecular structure. Ultrasound produces images from sound waves, and
positron emission tomography scans the body with antimatter.
The treatment of mental illnesss first became scientific and successful in the
20th century. Austrian physician and neurologist Sigmund Freud pioneered the
methods of psychoanalysis

Paramedic Neomi Zvi - Feb 2000