|
|
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.
Drugs are in development that may cure asthma and hay fever once and for all. They target leukotrienes, which are known to cause tightening of the air passages in the lungs and increase mucus productions in nasal passages.
Cancer has been around as long as humankind, but only in the second half of the twentieth century did the number of cancer cases explode.
Signs of depression include feeling sad most of the time for 2 weeks or longer; loss of interest in things normally enjoyed; lack of energy; sleep and appetite disturbances; weight changes; feelings of hopelessness, helplessness, or worthlessness; an inability to make decisions; and thoughts of death and suicide.
Dogs have been used in studies to detect various cancers in human subjects. They have been trained to sniff breath samples from humans that were collected by having them breathe into special tubes. These people included 55 lung cancer patients, 31 breast cancer patients, and 83 cancer-free patients. The dogs detected 54 of the 55 lung cancer patients as having cancer, detected 28 of the 31 breast cancer patients, and gave only three false-positive results (detecting cancer in people who didn't have it).
![C, A nurse can also administer the medication by setting the dose and rate with an electronic infusi](https://biology-forums.com/gallery/47/medium_18099_26_09_12_4_35_15.jpeg)
![This slave burial service, painted by John Antrobus in 1860, reflects an inversion of power relation](https://biology-forums.com/gallery/47/medium_375552_19_08_15_9_09_52_2232277.jpeg)