Figure 1.

Contamination of growth-hormone extracts. Before 1985, people in need of growth-hormone treatment were treated with cadaver-derived human growth hormone (c-hGH). To prepare c-hGH, the pituitary gland at the base of the brain was extracted at autopsy. Of the thousands of glands extracted, a few contained prions from people with the neurodegenerative condition Creutzfeldt–Jakob disease (CJD). Jaunmuktane et al.[4] report that some of the glands probably also contained seeds of amyloid-β protein (Aβ), possibly from people with Alzheimer's disease. The pooled glands were homogenized and the c-hGH was then extracted and injected into patients. After approximately 30 years, some recipients died of CJD, owing to a build-up of prions. The authors show that some of these people also had Aβ deposits in the brain, suggestive of incipient Alzheimer's disease.