AA amyloidosis is a potential complication of chronic inflammation or infection, for example, rheumatoid arthritis and tuberculosis, and is characterised by systematic deposition of protein fibrils in the tissues of organs such as the spleen and liver. Similar deposition, but of other proteins, also occurs in diseases such as Alzheimer's disease, Parkinson’s disease, and prion-associated disease ("mad cow disease").
In her thesis, Randi Sørby used experimental amyloidosis in the mink as a model to study how amyloid deposition arises in different parts of the spleen. This model was chosen because the mink has especially well-developed ellipsoids, which are lacking in the more commonly-used experimental animals such as mouse and rat, but which are found in most other mammals, including man. Studies have shown that ellipsoids are central structures in amyloid deposition and that they play an early role in the development of the disease.
In addition to amyloid fibrils, other proteins have been demonstrated (amyloid P component and apolipoproteins) and long polysaccharides (glycosaminoglycans)that may also be significant for the development of the depositions. One particularly interesting find was that several of these molecules were already present normally in the ellipsoids, which may help to explain why ellipsoids are involved so early.
The structure and general functions of ellipsoids were also studied. Sørby showed that ellipsoids also in mink are an effective filter of blood plasma. Various substances injected into the blood, such as carbon particles, small plastic spheres, and antigen-antibody complexes, were effectively removed by cells in the wall of the ellipsoids. These filtering qualities very likely play a role in he the development of the amyloid depositions.
The experimental model of amyloidosis in the mink has been further refined by injecting an extract of amyloid-containing tissue ("amyloid enhancing factor"). In this method, amyloid deposition develops significantly faster and shows a more predictable progression. This will enable future studies of the ellipsoid's role in the earliest phases of amyloidosis development.
Cand. med. vet. Randi Sørby defended her thesis for the degree of Philosophiae Doctor(PhD) on May 30, 2008, with the title "The involvement of splenic microenvironments, with emphasis on the ellipsoids, in experimental AA amyloidosis in mink."
The work was carried out at the Department of Basic Sciences & Aquatic Medicine of the Norwegian School of Veterinary Science, and was a collaboration with Dr. med. Tale Nordbye Wien and Professor Gunnar Husby of the Rikshospitalet University Hospital HF.
Magnhild Jenssen | alfa
Water forms 'spine of hydration' around DNA, group finds
26.05.2017 | Cornell University
How herpesviruses win the footrace against the immune system
26.05.2017 | Helmholtz-Zentrum für Infektionsforschung
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
26.05.2017 | Life Sciences
26.05.2017 | Life Sciences
26.05.2017 | Physics and Astronomy