In April, contracts cytomegalovirus – an immune system problem.
No one knows exactly what causes psoriasis, but some think it's related to an immune system problem in which overactive T cells attack healthy cells by mistake.
If someone is at risk for either a mass or raised ICP (recent head injury, a known immune system problem, localizing neurological signs, or evidence on examination of a raised ICP), a CT or MRI scan is recommended prior to the lumbar puncture.
Of those who die, Dr. Schuchat said, about three-quarters have some underlying condition like morbid obesity, pregnancy, asthma, diabetes or immune system problems.
The chemicals have been linked to cancer in some studies, and the federal Department of Health and Human Services lists them as having the potential for causing acute and chronic neurological and pulmonary problems, kidney and liver disease and immune system problems.
While the advice about tuna and salmon is directed at specific groups, there are studies that suggest heavy fish eaters could be at risk because mercury may contribute to cardiovascular disease, neurological problems and immune system problems.
Dr. Richard P. Wenzel, an infectious disease specialist at Virginia Commonwealth University, who wrote an editorial about the studies, said he would recommend the approach primarily for serious operations like heart surgery or joint replacements, or patients with immune system problems.
In addition, Dr. Fred Mettler, chairman of radiology at the University of New Mexico, said that just solving the immune system problems might not be enough because people could still die months later from other types of radiation-induced damage, such as to the lungs.
Myers defends the creation of chimeras as "legitimate and useful scientific research," such as when scientists insert human genes into mice to create "an animal model of Down syndrome, so that, for example, we could figure out exactly what gene overdose is causing the immune system problems or the heart defects, and develop better treatments for them".
While Apple and Mr. Jobs provided no more details of his illness, Mr. Jobs suffers from immune system problems common in people who have received liver transplants, said a person who knows him well, but who requested anonymity in order to maintain a relationship.
Sufferers may experience widespread muscle and joint pain, immune system problems, headaches, and many other symptoms.
