Dual roles of Incenp crucial to the assembly of the acentrosomal metaphase spindle in female meiosis

Spindle formation in female meiosis differs from mitosis in many animals, as it takes place independently from centrosomes, and the molecular requirements of this pathway remain to be understood. Here we report two crucial roles of Incenp, an essential subunit of the chromosomal passenger complex (the Aurora B complex), in centrosome-independent spindle formation in Drosophila female meiosis. Firstly, the initial assembly of spindle microtubules is drastically delayed in an incenp mutant. This clearly demonstrates, for the first time, a crucial role for Incenp in chromosome-driven spindle microtubule assembly in living oocytes. Additionally, Incenp is necessary to stabilise the equatorial region of the metaphase I spindle, in contrast to mitosis, where the equivalent function becomes prominent after anaphase onset. Our analysis suggests that Subito, a kinesin-6 protein, cooperates with Incenp for this latter function, but not microtubule assembly. We propose that the two functions of Incenp are part of the mechanisms that compensate for the lack of centrosomes during meiotic spindle formation

ALADIN is Required for the Production of Fertile Mouse Oocytes

Asymmetric cell divisions depend on the precise placement of the spindle apparatus. In mammalian oocytes, spindles assemble close to the cell's center, but chromosome segregation takes place at the cell periphery where half of the chromosomes are expelled into small, nondeveloping polar bodies at anaphase. By dividing so asymmetrically, most of the cytoplasmic content within the oocyte is preserved, which is critical for successful fertilization and early development. Recently we determined that the nucleoporin ALADIN participates in spindle assembly in somatic cells, and we have also shown that female mice homozygously null for ALADIN are sterile. In this study we show that this protein is involved in specific meiotic stages, including meiotic resumption, spindle assembly, and spindle positioning. In the absence of ALADIN, polar body extrusion is compromised due to problems in spindle orientation and anchoring at the first meiotic anaphase. ALADIN null oocytes that mature far enough to be fertilized in vitro are unable to support embryonic development beyond the two-cell stage. Overall, we find that ALADIN is critical for oocyte maturation and appears to be far more essential for this process than for somatic cell divisions

The role of temperature and frequency on fretting wear of a like-on-like stainless steel contact

The influences of environmental temperature and fretting frequency on the mechanisms and rates of wear in a like-on-like 304 stainless steel contact were examined, and mainly attributed to changes in the mechanical response of the bulk material and to changes in the behaviour of the oxide debris formed in the fretting process. At low temperatures, wear proceeds by continual oxide formation and egress from the contact, whilst at high temperatures, the rate of wear is much reduced, associated with the development of oxide formed into a protective bed within the contact. The temperature at which the change between these two behaviours took place was dependent upon the fretting frequency, with evidence that, at this transition temperature, changes in behaviour can occur as the fretting test proceeds under a fixed set of conditions. An interaction diagram has been developed which provides a coherent framework by which the complex effects of these two parameters can be rationalised in terms of widely accepted physical principles

New insights in formaldehyde-induced detoxification of the tetanus toxin: Chemical modification stoichiometry and characterization of intra- and inter-molecular cross-links

The active ingredient of the tetanus vaccine, known as tetanus toxoid (TTD, 150 kDa), is prepared by inactivation of the tetanus toxin with formaldehyde. This chemical treatment determines the efficiency and innocuity of the vaccine. The detoxification chemistry has been qualitatively studied regarding the nature and positioning of some formaldehyde-induced modifications. However, neither the stoichiometry of the chemical modifications or intra- and inter-chain cross-linking have been yet characterized, despite being of great interest for the definitive elucidation of the detoxification mechanism as well as for future manufacturing follow-up. The aim of the present study is to assess the impact of formaldehyde on TTD by identifying, mapping, and quantifying as exhaustively as possible, all formaldehyde-induced modifications over the entire three-dimensional (3D) structure of the protein. Please click Download on the upper right corner to see the full abstract

Les estampes japonaises des collections de KBR : des défis spécifiques pour la catalographie et la conservation-restauration

Dans le contexte du développement du japonisme en Europe à la fin du 19e siècle, le Cabinet des Estampes de KBR fait l’acquisition de ses premières estampes japonaises. On n’y retrouve que des œuvres d’excellente qualité technique et de tout premier choix artistique. De nouveaux achats sont réalisés jusqu’en 1987, portant le fonds à quelque 765 pièces et en faisant l’un des plus prestigieux d’Europe, reconnu dans le monde entier.Cet article traite de deux projets développés à partir de 2020 autour de ce fonds : l’un qui visait à l’encodage et à la numérisation systématique du fonds, et l’autre qui avait pour objet la conservation-restauration d’une sélection d’estampes. Nous évoquons tout d’abord les difficultés liées au référencement de ces 765 estampes dans le catalogue informatisé et dans les collections numérisées de KBR : s’agissant d’œuvres extra-européennes, elles nous confrontent à une autre langue, une autre graphie, d’autres références culturelles et symboliques, d’autres systèmes d’identification et de datation.Ensuite, nous abordons les spécificités matérielles des estampes japonaises : la diversité des papiers japonais, les principales caractéristiques des colorants et autres techniques de décors utilisés. Ces éléments sont déterminants dans l’élaboration des protocoles de traitements de conservation-restauration. À travers les interventions menées sur une petite sélection d’estampes, nous souhaitons montrer que l’approche et les techniques de restauration que nous utilisons couramment sur nos collections occidentales sont adaptables et applicables sur ces estampes extra-européennes, tant qu’on prend garde à respecter leurs spécificités techniques, matérielles et conceptuelles. Ainsi, il nous est possible d’améliorer à court et long terme les conditions de conservation des estampes japonaises sans feindre des traditions qui ne sont pas les nôtres, ni dénaturer le « monde éphémère et flottant » des ukiyo‑e.In the context of the development of Japonisme in Europe at the end of the 19th century, the KBR Prints & Drawings Cabinet received its first Japanese prints, selecting only works of excellent technical quality and of the highest artistic standards. Further purchases were made until 1987, bringing the collection to some 765 items and making it one of the most prestigious in Europe, recognized throughout the world.This article looks at two different projects both developed from 2020 around this collection: the first one aimed at the systematic encoding and digitization of the collection while the other one focused on the conservation and restoration processes of a selection of prints.We first mention the difficulties involved in referencing these 765 prints in the KBR’s computerized catalog and digitized collections: by not being European works, the prints confront us with another language, another written form, other cultural and symbolic references, other identification and dating systems.We then look at the specifications and material characteristics of Japanese prints: the diversity of Japanese papers, the main characteristics of the traditional dyes and other decorative techniques that were used during the fabrication process. These elements are crucial to the development of conservation-restoration treatment protocols. Through the interventions carried out on a small selection of prints, we wish to show that the approach and the restoration techniques that we commonly use on our Western collections are adaptable and applicable to these non-European prints, as long as we take care to respect their technical, material and conceptual characteristics and specificities. It is thus possible for us to improve in the short and long term the conservation conditions of Japanese prints without feigning traditions that are not ours, nor distorting the "ephemeral and floating world" of ukiyo-e.In het kader van de ontwikkeling van het Japonisme in Europa aan het einde van de 19e eeuw verwierf het Prentenkabinet van KBR zijn eerste Japanse prenten. Dit waren allemaal werken van uitstekende technische kwaliteit en met een hoge kunstwaarde. Verdere aankopen vonden plaats tot 1987, waardoor de collectie uitgroeide tot ongeveer 765 stukken en een van de meest prestigieuze in Europa werd, erkend over de hele wereld.Dit artikel gaat over twee verschillende projecten die vanaf 2020 werden ontwikkeld rond deze collectie: het eerste project richtte zich op het systematisch coderen en digitaliseren van de collectie, terwijl het tweede zich richtte op het conserverings- en restauratieproces van een selectie prenten.We vermelden eerst de moeilijkheden die gepaard gaan met het annoteren van deze 765 prenten in de geautomatiseerde catalogus en gedigitaliseerde collecties van de KBR: doordat het geen Europese werken zijn, confronteren de prenten ons met een andere taal, een andere geschreven vorm, andere culturele en symbolische referenties, andere identificatie- en dateringssystemen.Vervolgens nemen we de materiële kenmerken van de Japanse prenten onder de loep: de diversiteit aan Japanse papiersoorten, de belangrijkste kenmerken van de traditionele kleurstoffen en andere decoratieve technieken die werden gebruikt. Deze elementen zijn cruciaal voor de ontwikkeling van conserverings- en restauratieprotocollen. Aan de hand van de interventies die we hebben uitgevoerd op een kleine selectie prenten, willen we aantonen dat de aanpak en de restauratietechnieken die we gewoonlijk gebruiken voor onze westerse collecties, aanpasbaar en toepasbaar zijn op deze niet-Europese prenten. Dit op voorwaarde dat we hun technische, materiële en conceptuele eigenheden respecteren. Zo is het voor ons mogelijk om op korte en lange termijn de conserveringsomstandigheden van de Japanse prenten te verbeteren zonder tradities te voor te wenden die niet de onze zijn en zonder de "vluchtige en zwevende wereld" van de ukiyo-e te verstoren

Hydroxychloroquine in a G6PD-Deficient Patient with COVID-19 Complicated by Haemolytic Anaemia: Culprit or Innocent Bystander?

Hydroxychloroquine has been used worldwide as a first-line treatment for patients hospitalized with COVID-19. Little is known about COVID-19 and its effects on patients with congenital red blood cell disorders. We report a case of haemolytic anaemia in a 32-year-old patient and a fortuitous highlighting of G6PD deficiency. We reviewed the literature to assess the risk of hydroxychloroquine use in this context

From Investigating a Case of Cellulitis to Exploring Nosocomial Infection Control of ST1 Legionella pneumophila Using Genomic Approaches.

peer reviewedLegionella pneumophila can cause a large panel of symptoms besides the classic pneumonia presentation. Here we present a case of fatal nosocomial cellulitis in an immunocompromised patient followed, a year later, by a second case of Legionnaires' disease in the same ward. While the first case was easily assumed as nosocomial based on the date of symptom onset, the second case required clear typing results to be assigned either as nosocomial and related to the same environmental source as the first case, or community acquired. To untangle this specific question, we applied core-genome multilocus typing (MLST), whole-genome single nucleotide polymorphism and whole-genome MLST methods to a collection of 36 Belgian and 41 international sequence-type 1 (ST1) isolates using both thresholds recommended in the literature and tailored threshold based on local epidemiological data. Based on the thresholds applied to cluster isolates together, the three methods gave different results and no firm conclusion about the nosocomial setting of the second case could been drawn. Our data highlight that despite promising results in the study of outbreaks and for large-scale epidemiological investigations, next-generation sequencing typing methods applied to ST1 outbreak investigation still need standardization regarding both wet-lab protocols and bioinformatics. A deeper evaluation of the L. pneumophila evolutionary clock is also required to increase our understanding of genomic differences between isolates sampled during a clinical infection and in the environment