Abstract: An illustrative method of performing reference-based data-dependent tandem mass spectrometry includes directing a mass spectrometer to acquire an MS1 mass spectrum of ions produced from a sample, identifying, based on the MS1 mass spectrum, an observed precursor ion that corresponds to a target ion included in an inclusion list, directing, based on the identifying of the observed precursor ion, the mass spectrometer to acquire an MS2 mass spectrum associated with the observed precursor ion, and removing, when the acquired MS2 mass spectrum associated with the observed precursor ion is within a threshold similarity of a reference MS2 mass spectrum associated with the target ion, the target ion from the inclusion list.

Abstract: The invention relates to a method for detecting progressive, chronic dementia diseases or a predisposition to such diseases or method for the prognosis of such diseases. For this purpose, the concentration of particular peptides in body fluids or other samples from the patient is measured in a method which can be carried out in a laboratory. The invention further relates to peptides which have been found for determining the presence and/or the grade of the progressive, chronic dementia disease. The invention additionally relates to detection reagents such as antibodies and nucleic acids and the like for detecting said peptides or the corresponding nucleic acids.

Abstract: The invention relates to defined peptides and the quantitative determination thereof in biological samples from patient's suffering from Alzheimer's disease, in relation to the concentration thereof in a control group. The invention also relates to the use of said peptides for therapeutic purposes. The inventive peptides come from a protein precursor having the corresponding gene and are processed in a specific manner and modified in a post-translation manner. Changes in the concentrations of said peptides indicate Alzheimer's disease, and the direction of the change in concentration is specifie for each peptide. Alzheimer's disease is detected by identifying the peptides individually or in groups. The invention can also be used to control the course of Alzheimer's disease, for the prognosis thereof and for the development of therapeutic agents to combat the same.