Bone marrow graft versus peripheral blood graft in haploidentical hematopoietic stem cells transplantation: a retrospective analysis in1344 patients of SFGM-TC registry.

peer reviewedThe use of peripheral blood (PB) or bone marrow (BM) stem cells graft in haploidentical hematopoietic stem cell transplantation with post-transplant cyclophosphamide (PTCy) for graft-versus-host disease (GVHD) prophylaxis remains controversial. Moreover, the value of adding anti-thymoglobulin (ATG) to PTCy is unknown. A total of 1344 adult patients received an unmanipulated haploidentical transplant at 37 centers from 2012 to 2019 for hematologic malignancy. We compared the outcomes of patients according to the type of graft, using a propensity score analysis. In total population, grade II-IV and III-IV acute GVHD (aGVHD) were lower with BM than with PB. Grade III-IV aGVHD was lower with BM than with PB + ATG. All outcomes were similar in PB and PB + ATG groups. Then, in total population, adding ATG does not benefit the procedure. In acute leukemia, myelodysplastic syndrome and myeloproliferative syndrome (AL-MDS-MPS) subgroup receiving non-myeloablative conditioning, risk of relapse was twice greater with BM than with PB (51 vs. 22%, respectively). Conversely, risk of aGVHD was greater with PB (38% for aGVHD II-IV; 16% for aGVHD III-IV) than with BM (28% for aGVHD II-IV; 8% for aGVHD III-IV). In this subgroup with intensified conditioning regimen, risk of relapse became similar with PB and BM but risk of aGVHD III-IV remained higher with PB than with BM graft (HR = 2.0; range [1.17-3.43], p = 0.012)

Diversity, paleobiology and ecology of Organic-walled Microfossils from the Proterozoic of Arctic Canada, and implications for early eukaryotic evolution.

Understanding the appearance and evolution of Life on our Planet (and elsewhere?) requires multidisciplinary approaches intersecting, notably, biology, geology, chemistry and astronomy. Studies of Earth deep times provide insights on the early hydrosphere, atmosphere and geosphere which influenced the development of the early biosphere. Conversely, the transition from prebiotic chemistry to life and subsequent biological changes (prokaryotic then eukaryotic photosynthesis, rise of eukaryotes, appearance of crown-groups, …) also played a role in modifying our young planet. This study focuses on a fundamental period for the diversification of Life on earth, the Proterozoic, that span from 2500 to 541 Ma. The total diversity of organic-walled microfossils present in two unmetamorphosed sedimentary successions from the northwestern Canada was investigated: The Dismal Lakes Group and the lower Shaler Supergroup. These successions represent more than 700 million years of earth history (from 1600 to 900 Ma) and preserve beautiful and abundant microfossils, especially numerous taxa of eukaryotes. This thesis demonstrates that the major diversification of eukaryotes observed in the fossil record at ~800 Ma has, in fact, started earlier and was more gradual. Eukaryotes were diversified by the early Mesoproterozoic and crown groups might have already appeared by then. New and earlier evidence for eukaryovory permits to suggest that predation was probably a powerful driver of this diversity rise. By combining classical paleontological approaches with spectroscopic and ultrastructural analyses, a new candidate of crown-group eukaryote, Ourasphaira giraldae could be proposed. This microfossil, recognized as an early fungus, provides new insights into crown-group diversification in the Proterozoic but also a new calibration point for molecular clock estimates of early eukaryotic evolution, and in particular of the Opisthokontes. Collectively, these studies show that northwestern Canada is an exceptional window on early eukaryotes evolution.Comprendre l’apparition et l’évolution de la vie sur Terre (et ailleurs ?) requiert une approche pluridisciplinaire à la croisée de la biologie, de la géologie, de la chimie et de l’astronomie. Les études des temps reculés de la Terre nous fournissent des informations précieuses sur l’hydrosphère, l’atmosphère et la géosphère primitives ; lesquelles ont influencé le développement de la biosphère. Inversément, la transition de la chimie pré-biotique vers la vie et les changements biologiques qui ont suivis (photosynthèse procaryote puis eucaryote, diversification des eucaryotes puis de leurs groupes couronnes, …) ont également joué un rôle dans les modifications de notre jeune planète. Cette étude se concentre sur une période fondamentale pour la diversification de la vie sur terre, le Protérozoïque, qui s’étend de 2500 à 541 million d’années. Dans ce travail, la diversité totale de microfossiles à parois organiques présente dans deux successions sédimentaires non métamorphisées de l’arctique Canadien a été étudiée : Le Groupe du Dismal Lakes et le Supergroupe inférieur du Shaler. Ces successions représentent plus de 700 millions d’années de l’histoire de la Terre et préservent d’abondants et superbes microfossiles, notamment de nombreux eucaryotes. Cette thèse démontre que la diversification majeure des eucaryotes, observée dans le registre fossile à environ 800 Ma, avait débuté plus tôt et était en fait plus progressive. Les eucaryotes étaient déjà diversifiés au début du Mésoprotérozoïque et les groupes couronnes étaient peut-être déjà présents. De plus, la découverte de traces d’eucaryovorie plus anciennes permet de suggérer que la prédation constituait sans doute un facteur important de cette hausse de diversité. En combinant des méthodes classiques d’investigation paléontologique avec des analyses spectroscopiques et ultrastructuralles, un nouveau candidat pour un groupe couronne eucaryote, Ourasphaira giraldae a pu être proposé. Ce microfossile, interprété comme un membre précoce des champignons, nous fournit des informations sur la diversification des groupes couronnes et un nouveau point de calibration pour les horloges moléculaires testant l’évolution des premiers eucaryotes. Collectivement, ces études montrent que le nord-ouest canadien constitue une formidable fenêtre sur l’évolution des premiers eucaryotes.Diversity, paleobiology and ecology of Organic-walled Microfossils from the Proterozoic of Arctic Canada, and implications for early eukaryotic evolution

Biodiversiteten av eukaryotiska mikrofossil med organiska cellväggar från Visingsögruppen (tonian), Sverige

The diversification of unicellular, auto- and heterotrophic protists and the appearance of multicellular microorganisms is recorded in numerous Tonian age successions worldwide, including the Visingsö Group in southern Sweden. The Tonian Period (1000-720 Ma) was a time of changes in the marine environments with increasing oxygenation and a high input of mineral nutrients from the weathering continental margins to shallow shelves, where marine life thrived. This is well documented by the elevated level of biodiversity seen in global microfossil record. The Visingsö Group contains a taxonomically rich assemblage of cyanobacteria, stromatolites, algal phytoplankton, and vase-shaped microfossils. A new study of organic-walled, phytoplanktic microfossils, which are extracted by palynological method from the Visingsö 1 borehole samples, reveals the presence of morphologically disparate taxa. They are in gross cysts of microalgae (Pterospermopsimorpha, Pterospermella, Cerebrosphaera, Trachysphaeridium, Simia and certain Leiosphaeridia with pylome) and some are of uncertain affinities (acritarchs). Representative taxa of two lineages among green algae, Prasinophyceae and Chlorophyceae, are recognized. Cyanobacterial clusters and filaments are abundant and specimens of multicellular, yet systematically unrecognized taxa are recorded. Taxonomically, the assemblage is similar to some from other successions distributed along the margins of Baltica, Laurentia and Siberia in the Tonian Period. The ecological habitats of those organisms are inferred by comparing with their potential modern analogues and from the sedimentological setting of the upper formation of the Visingsö Group.Denna studie handlar om biodiversiteten och den biologiska affiniteten av mikrofossil från den neoproterozoiska eran, tonianperioden (1000-720 Ma). De har extraherats från övre formationen av Visingsögruppen i södra Sverige.Mikrofossilen har organiska cellväggar, är encelliga och har förmodats representera algcystor (resistenta reproduktiva strukturer), cyanobakterier, och andra organismer av okänd tillhörighet. Neoproterozoikum har den högsta graden av biologisk diversitet under prekambrium. Det är därför viktigt att studera diversiteten för att förstå utvecklingen av biosfären under denna period i samband med utvecklingen av miljöer. Den studerade samlingen härrör från ett borrhål på Visingsö i Vättern, och visar på större diversitet än från tidigare studier.Denna nya studie syftar till att bestämma biodiversiteten i den övre formationen av Visingsögruppen och att känna igen affiniteten av mikrofossilen med organiska väggar och deras ekologi. Vissa av de undersökta mikrofossilen hör sannolikt till grönalgerna. Kluster och fiber av cyanobakterier är rikligt förekommande, och några prover är ej biologiskt igenkännbara. Med hjälp av moderna analoger och sedimentologiska data är ekologin hos dessa mikrofossil utlä

Diversity and paleobiology of Proterozoic organic-walled microfossils from Arctic Canada

peer reviewe

ATR-FTIR spectra Rhynie chert fossils

The affinities of extinct organisms are often difficult to resolve using morphological data alone. Chemical analysis of carbonaceous specimens can complement traditional approaches, but the search for taxon-specific signals in ancient, thermally altered organic matter is challenging and controversial, partly because suitable positive controls are lacking. Here, we show that non-destructive Fourier Transform Infrared Spectroscopy (FTIR) resolves in-situ molecular fingerprints in the famous 407-Ma Rhynie chert fossil assemblage of Aberdeenshire, Scotland, an important early terrestrial Lagerstätte. Remarkably, unsupervised clustering methods (principal components analysis and K-mean) separate the fossil spectra naturally into eukaryotes and prokaryotes (cyanobacteria). Additional multivariate statistics and machine-learning approaches also differentiate prokaryotes from eukaryotes, and discriminate eukaryotic tissue types, despite the overwhelming influence of silica. We find that these methods can clarify the affinities of morphologically ambiguous taxa; in the Rhynie chert for example, we show that the problematic "nematophytes" have a plant-like composition. Overall, we demonstrate that the famously exquisite preservation of cells, tissues and organisms in the Rhynie chert accompanies similarly impressive preservation of molecular information. These results provide a compelling positive control that validates the use of infrared spectroscopy to investigate the affinity of organic fossils in chert. The dataset is related to the upcoming publication: Loron, C.C, Rodriguez, E., Orr, P.J., Gromov, A.V., Fraser, N.C., & McMahon, S. (in submission) Molecular fingerprints resolve affinities of Rhynie chert organic fossils. Nature Communication