Secretion both DNA and proteins. It was discovered in "Agrobacterium tumefaciens", which uses this system to introduce the T-DNA portion of the Ti plasmid into the plant host, which in turn causes the affected area to develop into a crown gall (tumor). "Helicobacter pylori" uses a type IV secretion system to deliver CagA into gastric epithelial cells, which is associated with gastric carcinogenesis. "Bordetella pertussis", the causative agent of whooping cough, secretes the pertussis toxin partly through the type IV system. "Legionella pneumophila", the causing agent of legionellosis (Legionnaires' disease) utilizes a type IVB secretion system, known as the icm/dot (intracellular
Alzheimer's disease biomarkers Alzheimer's disease biomarkers The Alzheimer's disease biomarkers are neurochemical indicators used to assess the risk or presence of the disease. The biomarkers can be used to diagnose Alzheimer's disease (AD) in a very early stage, but they also provide objective and reliable measures of disease progress. It is imperative to diagnose AD disease as soon as possible, because neuropathologic changes of AD precede the symptoms by years. It is well known that beta amyloid (Aβ) is a good indicator of AD disease, which has facilitated doctors to accurately pre-diagnose cases of AD disease. When Aβ peptide is released by proteolytic