Case report of a cervical myelomalacia caused by a thoracolumbar intradural disc herniation leading to intracranial hypotension

Journal of Neurology - A 50-year-old patient was admitted with symptoms of intracranial hypotension. MRI revealed a cervical myelomalacia caused by engorged epidural veins leading to a stenosis of...     

Diagnosis and follow-up evaluation of central nervous system vasculitis: an evaluation of vessel-wall MRI findings

Journal of Neurology - To approach the clinical value of MRI with vessel wall imaging (VWI) in patients with central nervous system vasculitis (CNSV), we analyzed patterns of VWI findings both at...     

Proteolipid protein modulates preservation of peripheral axons and premature death when myelin protein zero is lacking

Protein zero (P0) is the major structural component of peripheral myelin. Lack of this adhesion protein from Schwann cells causes a severe dysmyelinating neuropathy with secondary axonal degeneration in humans with the neuropathy Dejerine‐Sottas syndrome (DSS) and in the corresponding mouse model (P0^null‐mice). In the mammalian CNS, the tetraspan‐membrane protein PLP is the major structural myelin constituent and required for the long‐term preservation of myelinated axons, which fails in hereditary spastic paraplegia (SPG type‐2) and the relevant mouse model (Plp^null‐mice). The Plp‐gene is also expressed in Schwann cells but PLP is of very low abundance in normal peripheral myelin; its function has thus remained enigmatic. Here we show that the abundance of PLP but not of other tetraspan myelin proteins is strongly increased in compact peripheral myelin of P0^null‐mice. To determine the functional relevance of PLP expression in the absence of P0, we generated P0^null*Plp^null‐double‐mutant mice. Compared with either single‐mutant, P0^null*Plp^null‐mice display impaired nerve conduction, reduced motor functions, and premature death. At the morphological level, axonal segments were frequently non‐myelinated but in a one‐to‐one relationship with a hypertrophic Schwann cell. Importantly, axonal numbers were reduced in the vital phrenic nerve of P0^null*Plp^null‐mice. In the absence of P0, thus, PLP also contributes to myelination by Schwann cells and to the preservation of peripheral axons. These data provide a link between the Schwann cell‐dependent support of peripheral axons and the oligodendrocyte‐dependent support of central axons. GLIA 2016;64:155–174     

Redox effects and formation of gold nanoparticles for the nucleation of low thermal expansion phases from BaO/SrO/ZnO/SiO2 glasses

Glasses in the system BaO/SrO/ZnO/SiO₂ containing 0.01 and 0.1 mol% gold were used to study the formation of gold nanoparticles with the aim to use them as nucleation agents. In order to promote gold clustering, the glasses were additionally doped with 0.5 mol% Sb₂O₃. Depending on the heat treatment schedule, Au particle sizes were in the range from 6 to above 50 nm. In contrast to many other gold ruby glass systems, the clustering is completely prevented by the absence of antimony; then the glasses remain colorless. Surprisingly, at higher temperatures, a re-dissolution of gold clusters was also observed, which now allows the formulation of a more comprehensive model concerning the redox and clustering behavior. This growth model is completed by the fact that a high gold concentration enables the stabilization of much smaller Au clusters. Mie theory with the aid of quantum confined size-dependent dielectric functions was successfully used to describe the optical behavior of the gold nanoparticles also for sizes below 10 nm. These results were confirmed using high resolution scanning transmission electron microscopy, including energy dispersive X-ray spectroscopy. It could also be shown that small gold particles up to a size of 50 nm are not effective as nucleating agents.

Glasses in the system BaO/SrO/ZnO/SiO₂ containing 0.01 and 0.1 mol% gold were used to study the formation of gold nanoparticles with the aim to use them as nucleation agents.     

Uncoupling of neuroinflammation from axonal degeneration in mice lacking the myelin protein tetraspanin‐2

Deficiency of the major constituent of central nervous system (CNS) myelin, proteolipid protein (PLP), causes axonal pathology in spastic paraplegia type‐2 patients and in Plp1^null‐mice but is compatible with almost normal myelination. These observations led us to speculate that PLP's role in myelination may be partly compensated for by other tetraspan proteins. Here, we demonstrate that the abundance of the structurally related tetraspanin‐2 (TSPAN2) is highly increased in CNS myelin of Plp1^null‐mice. Unexpectedly, Tspan2^null‐mutant mice generated by homologous recombination in embryonic stem cells displayed low‐grade activation of astrocytes and microglia in white matter tracts while they were fully myelinated and showed no signs of axonal degeneration. To determine overlapping functions of TSPAN2 and PLP, Tspan2^null*Plp1^null double‐mutant mice were generated. Strikingly, the activation of astrocytes and microglia was strongly enhanced in Tspan2^null*Plp1^null double‐mutants compared with either single‐mutant, but the levels of dysmyelination and axonal degeneration were not increased. In this model, glial activation is thus unlikely to be caused by axonal pathology, and vice versa does not potentiate axonal degeneration. Our results support the concept that multiple myelin proteins have distinct roles in the long‐term preservation of a healthy CNS, rather than in myelination per se. GLIA 2013;61:1832–1847     

Extended stereotactic brain biopsy in suspected primary central nervous system angiitis: good diagnostic accuracy and high safety

Journal of Neurology - To evaluate the diagnostic accuracy and safety of extended stereotactic brain biopsy (ESBB) in a single center cohort with suspected primary angiitis of the central nervous...     

Zur Frage der Mitwirkung hormonaler Faktoren bei den Schizophrenien

Zusammenfassung Es wird die Frage diskutiert, inwieweit hormonale Faktoren bei der Manifestierung schizophrener Erkrankungen beteiligt sind. In bestimmten hormonalen Phasen können endokrine Faktoren, mindestens bei einer Gruppe der Schizophrenien, zum Ausbruch dieser Erkrankungen beitragen. Auf welchen Wegen dies geschieht und wodurch diese Krankheitsgruppe charakterisiert ist, läßt sich noch nicht sagen. Klinische und genetische Gesichtspunkte lassen daran denken, daß hormonales Geschehen und abwegige Stoffwechselvorgänge, z. B. in den Nervenzellen bestimmter Hirnareale, koordiniert ablaufen. An dem Krankheitsverlauf einer Patientin aus einer Gruppe von schizophren-Kranken mit auffallenden hormonalen Störungen werden diese Auffassungen kurz erläutert.Herra Professor Dr. Otto Hahn zum 75. Geburtstag.