For linkage purposes, subjects were selected if they had received the vaccine between 1970 and 1974.
In population studies, such linkage is subject to the confounding effect of the natural history of Alzheimer's disease often characterized by weight loss, which precedes the diagnosis of this condition (8).
In these 570 subjects, linkage analysis showed strong linkage (LOD = 7.0) of plasma trehalase activity to markers on Chromosome 11q23 at 131 cM, near the TREH locus (Fig. 2).
However, this O-linkage was subject to β-glucosidases in vivo, which reduced their utility and prompted development of more metabolically stable C-linkage SGLT2 inhibitors.
Another possibility is through record linkage of the study subjects to large existing databases, e.g., data pertaining to health insurance, traffic violations, internet usage, etc., where a great number of variables can be found or defined preceding the study outcome [ 2].
After record linkage, 2,468 (98.7%) subjects were successfully traced.
The record linkage yielded 117 subjects registered with the diagnosis of pancreatic cancer in the Malmö Preventive Project.
Since many genetic association and linkage studies use subjects of different ages, an additional criterion is genetic stability, where the same set of genes is seen to influence the endophenotype across a wide age range.
Meselamine was linked with L-glutamine through azo linkage and was subjected to in vitro stability studies in aqueous buffers of varied pH range and rat fecal matter.
Diacerein was linked with D-glucosamine through amide linkage and was subjected to in vitro release studies in aqueous buffers of varied pH range.
