Science and Medicine

As many as 91 percent of the patients with mild memory impairment who had these risk markers went on to develop Alzheimer's within a 10-year period

The first changes in the brain of a person with Alzheimer’s disease can be observed as much as 10 years in advance—10 years before the person in question has become so ill that he or she can be diagnosed with the disease. This is what a new study from Lund University in Sweden has found.

Physician Oskar Hansson and his research group are studying biomarkers—substances present in spinal fluid and linked to Alzheimer’s disease. The group has studied close to 140 people with mild memory impairment, showing that a certain combination of markers (low levels of the substance beta-amyloid and high levels of the substance tau) indicate a high risk of developing Alzheimer’s disease in the future.

As many as 91 percent of the patients with mild memory impairment who had these risk markers went on to develop Alzheimer’s within a 10-year period. In contrast, those who had memory impairment but normal values for the markers did not run a higher risk of getting Alzheimer’s than healthy individuals. Oskar Hansson previously carried out a study showing that pathological changes can be seen in the brain of an Alzheimer’s patient five years before the diagnosis. The new study has thus doubled this time span to ten years.

Read more: Alzheimer’s Damage Occurs Early

With some exaggeration: medical practice helped in developing a superbug

Scientists of the Institute of Tropical Medicine discovered a parasite that not only had developed resistance against a common medicine, but at the same time had become better in withstanding the human immune system. With some exaggeration: medical practice helped in developing a superbug. For it appears the battle against the drug also armed the bug better against its host.

“To our knowledge it is the first time such a doubly armed organism appears in nature,” said researcher Manu Vanaerschot, who obtained a PhD for his detective work at ITG and Antwerp University. “It certainly makes you think.”

Vanaerschot studies the Leishmania parasite, a unicellular organism that has amazed scientists before. Leishmania is an expert in adaptation to different environments, and the only known organism in nature disregarding a basic rule of biology: that chromosomes ought to come in pairs. (The latter was also discovered by ITG-scientists recently.) The parasite causes leishmaniasis, one of the most important parasitic diseases after malaria. It hits some two million people, in 88 countries—including European ones—and annually kills fifty thousand of them. The parasite is transmitted by the bite of a sand fly. The combined resistance against a medicine and the human immune system emerged in Leishmania donovani, the species causing the deadly form of the disease.

Read more: Do Our Medicines Boost Pathogens?