Pituitary Neoplasm Nomenclature Workshop: Does Adenoma Stand the Test of Time?

The WHO Classification of Endocrine Tumours designates pituitary neoplasms as adenomas. A proposed nomenclature change to pituitary neuroendocrine tumors (PitNETs) has been met with concern by some stakeholder groups. The Pituitary Society coordinated the Pituitary Neoplasm Nomenclature (PANOMEN) workshop to address the topic. Experts in pituitary developmental biology, pathology, neurosurgery, endocrinology, and oncology, including representatives nominated by the Endocrine Society, European Society of Endocrinology, European Neuroendocrine Association, Growth Hormone Research Society, and International Society of Pituitary Surgeons. Clinical epidemiology, disease phenotype, management, and prognosis of pituitary adenomas differ from that of most NETs. The vast majority of pituitary adenomas are benign and do not adversely impact life expectancy. A nomenclature change to PitNET does not address the main challenge of prognostic prediction, assigns an uncertain malignancy designation to benign pituitary adenomas, and may adversely affect patients. Due to pandemic restrictions, the workshop was conducted virtually, with audiovisual lectures and written précis on each topic provided to all participants. Feedback was collated and summarized by Content Chairs and discussed during a virtual writing meeting moderated by Session Chairs, which yielded an evidence-based draft document sent to all participants for review and approval. There is not yet a case for adopting the PitNET nomenclature. The PANOMEN Workshop recommends that the term adenoma be retained and that the topic be revisited as new evidence on pituitary neoplasm biology emerges

The role of sulfoglucuronosyl glycosphingolipids in the pathogenesis of monoclonal IgM paraproteinemia and peripheral neuropathy

In IgM paraproteinemia and peripheral neuropathy, IgM M-protein secretion by B cells leads to a T helper cell response, suggesting that it is antibody-mediated autoimmune disease involving carbohydrate epitopes in myelin sheaths. An immune response against sulfoglucuronosyl glycosphingolipids (SGGLs) is presumed to participate in demyelination or axonal degeneration in the peripheral nervous system (PNS). SGGLs contain a 3-sulfoglucuronic acid residue that interacts with anti-myelin-associated glycoprotein (MAG) and the monoclonal antibody anti-HNK-1. Immunization of animals with sulfoglucuronosyl paragloboside (SGPG) induced anti-SGPG antibodies and sensory neuropathy, which closely resembles the human disease. These animal models might help to understand the disease mechanism and lead to more specific therapeutic strategies. In an in vitro study, destruction or malfunction of the blood-nerve barrier (BNB) was found, resulting in the leakage of circulating antibodies into the PNS parenchyma, which may be considered as the initial key step for development of disease

THE METHOD OF SHARP-POINTED SHARDS

A method of specimen preparation is presented which enables some important new classes of materials to be studied by field-ion microscopy, atom probe mass analysis, and field electron emission microscopy

A METHOD OF FIM-FEEM SPECIMEN PREPARATION OF SUPERCONDUCTING AND OTHER OXIDES

A new method is described for preparation of oxide specimens for field-ion and field-electron emission microscopy

LONG-RANGE ICOSOHEDRAL SYMMETRY IN A METALLIC PHASE OBSERVED BY FIELD ION MICROSCOPY

L'observation directe, par microscopie a champ ionique d'un alliage d'Aluminium et de Manganèse (Mn:12% Atomique) confirme la précédente mise en évidence, par des techniques de diffraction, d'une conformation icosohèdrale à grande échelle. De plus on remarque une grande quantité de désordre cristallin localisé présentant de nombreux défauts de structures "antiphase boundaries". L'existence d'un maclage systématique, qui aurait pu expliquer la symétrie d'orientation observée, n'a pas pu être démontrée.Direct observations by Field Ion Microscopy of an Al-12 at.% alloy confirm the earlier determination, by diffraction techniques, of icosohedral long range orientational order. Additionally, a large amount of local disorder, replete with defects or antiphase boundaries, is found. There is no evidence for systematic twinning which might account for the observed orientational symmetry

OBSERVATIONS OF TWO-LEAVED SPIRALS IN RUTHENIUM

Dislocations in a field-ion specimen under specified conditions give rise to a spiral contrast in field-ion micrographs. The nature of the spirals can be used to derive information concerning the Burgers vector of the dislocation. Such an analysis is applied here to the case of the two-leaved spirals from hexagonal close packed structures

EPITAXIAL GROWTH AND SOME PROPERTIES OF SAMARIUM CRYSTALS ON TUNGSTEN

La croissance cristalline de couches de samarium a été réalisée par déposition de vapeur sur des pointes de tungsten pour une étude par microscopie à émission de champ électronique et sur des monocristaux orientés (011) de tungstene pour une étude par diffraction des électron lents . Les conditions optimales de croissance ont été réalisées pour une température du substrat comprise entre 650 et 750 K. La relation d'épitaxie la plus couramment observée était (0001)Sm // (011)W avec [11-20]Sm // [001]W. Le paramètre cristallin du Sm dans le plan (0001) est de quelques pour cents supérieur à la valeur correspondant au volume.Samarium epitaxial crystalline layers have been grown by vapor deposition onto either tungsten field-electron emitters or a single macro-cyrstal, (011)-oriented tungsten low-energy-electron diffraction specimen. Optimum growth occurred for substrate temperatures in the range of 650 - 750 K. The epitaxial relationship most commonly observed was (0001)Sm // (011)W with [1120]Sm // [001]W. The surface lattice constant of Sm(0001) appears to be a few per cent larger than the bulk value

NUCLEATION AND GROWTH OF Cr ON STEPPED SURFACES WITH FACETS AN FEEM STUDY

Etude, par microscopie à effet de champs, de la nucléation et de la croissance épitaxiale de cristaux de Cr, formés par déposition de vapeur de Cr sur des surfaces de W et de Re nettoyées thermiquement. Les surfaces des substrats sont constituées de terrasses et de facettes de faibles indices, délimitées par des "marches" atomiques. Sur les surfaces de Re, la nucléation multiple conduisant à une croissance polycristalline semble inévitable. L'étude plus extensive du système Cr/W conduit à quelques résultats surprenants. Dans le domaine de température compris entre 500 et 1050 K, la nucléation et la croissance cristalline n'apparaît qu'après la formation d'une ou deux monocouches atomiques (mode Stranski-Krastanov). Cependant 300 K et sur la face (011) du W on observe nettement deux modes distincts de croissance en fonction de la géométrie du système de dépôt de vapeur ; le mode Stranski-Krastanov ou le mode Volmer-Weber.The nucleation and epitaxial growth of Cr crystals resulting from vapor-deposition of Cr onto thermally annealed W and Re surfaces has been studied using field electron emission microscopy. The substrate surfaces consisted of low-index facets and terraces separated by atomic steps. Multiple nucleation, leading to polycrystal growth, could not be avoided on the Re surfaces. The Cr/W system was studied more extensively and was found to yield some surprising results. In the temperature range of about 500-1050 K, nucleation and growth of Cr crystals occured only after 1-2 monolayers of Cr atoms had formed (the Stranski-Krastanov mode). However, at ~ 300 K on {011} W planes, two different growth modes were observed consistently depending upon the vapor-desposition geometry ; the Stranski-Krastanov or the Volmer-Weber mode