|
|
As the western states of America were settled, pioneers often had to drink rancid water from ponds and other sources. This often resulted in chronic diarrhea, causing many cases of dehydration and death that could have been avoided if clean water had been available.
IgA antibodies protect body surfaces exposed to outside foreign substances. IgG antibodies are found in all body fluids. IgM antibodies are the first type of antibody made in response to an infection. IgE antibody levels are often high in people with allergies. IgD antibodies are found in tissues lining the abdomen and chest.
In 1864, the first barbiturate (barbituric acid) was synthesized.
In the United States, an estimated 50 million unnecessary antibiotics are prescribed for viral respiratory infections.
There are over 65,000 known species of protozoa. About 10,000 species are parasitic.