45 research outputs found
A glimpse into the biogeography, seasonality, and ecological functions of arctic marine Oomycota
Source at https://doi.org/10.1186/s43008-019-0006-6. © The Author(s). 2019High-latitude environments are warming, leading to changes in biological diversity patterns of taxa. Oomycota are a group of fungal-like organisms that comprise a major clade of eukaryotic life and are parasites of fish, agricultural crops, and algae. The diversity, functionality, and distribution of these organisms are essentially unknown in the Arctic marine environment. Thus, it was our aim to conduct a first screening, using a functional gene assay and high-throughput sequencing of two gene regions within the 18S rRNA locus to examine the diversity, richness, and phylogeny of marine Oomycota within Arctic sediment, seawater, and sea ice. We detected Oomycota at every site sampled and identified regionally localized taxa, as well as taxa that existed in both Alaska and Svalbard. While the recently described diatom parasite Miracula helgolandica made up about 50% of the oomycete reads found, many lineages were observed that could not be assigned to known species, including several that clustered with another recently described diatom parasite, Olpidiopsis drebesii. Across the Arctic, Oomycota comprised a maximum of 6% of the entire eukaryotic microbial community in Barrow, Alaska May sediment and 10% in sea ice near the Svalbard archipelago. We found Arctic marine Oomycota encode numerous genes involved in parasitism and carbon cycling processes. Ultimately, these data suggest that Arctic marine Oomycota are a reservoir of uncharacterized biodiversity, the majority of which are probably parasites of diatoms, while others might cryptically cycle carbon or interface other unknown ecological processes. As the Arctic continues to warm, lower-latitude Oomycota might migrate into the Arctic Ocean and parasitize non-coevolved hosts, leading to incalculable shifts in the primary producer community
A Systematic Review of Three-Dimensional Printing in Liver Disease
The purpose of this review is to analyse current literature related to the clinical applications of 3D printed models in liver disease. A search of the literature was conducted to source studies from databases with the aim of determining the applications and feasibility of 3D printed models in liver disease. 3D printed model accuracy and costs associated with 3D printing, the ability to replicate anatomical structures and delineate important characteristics of hepatic tumours, and the potential for 3D printed liver models to guide surgical planning are analysed. Nineteen studies met the selection criteria for inclusion in the analysis. Seventeen of them were case reports and two were original studies. Quantitative assessment measuring the accuracy of 3D printed liver models was analysed in five studies with mean difference between 3D printed models and original source images ranging from 0.2 to 20%. Fifteen studies provided qualitative assessment with results showing the usefulness of 3D printed models when used as clinical tools in preoperative planning, simulation of surgical or interventional procedures, medical education, and training. The cost and time associated with 3D printed liver model production was reported in 11 studies, with costs ranging from US2000, duration of production up to 100 h. This systematic review shows that 3D printed liver models demonstrate hepatic anatomy and tumours with high accuracy. The models can assist with preoperative planning and may be used in the simulation of surgical procedures for the treatment of malignant hepatic tumours
Biparental inbreeding depression, genetic relatedness and progeny vigour in a wind-pollinated treeline species in Argentina
Fusarium: more than a node or a foot-shaped basal cell
Recent publications have argued that there are potentially serious consequences for researchers in recognising distinct genera in the terminal fusarioid clade of the family Nectriaceae. Thus, an alternate hypothesis, namely a very broad concept of the genus Fusarium was proposed. In doing so, however, a significant body of data that supports distinct genera in Nectriaceae based on morphology, biology, and phylogeny is disregarded. A DNA phylogeny based on 19 orthologous protein-coding genes was presented to support a very broad concept of Fusarium at the F1 node in Nectriaceae. Here, we demonstrate that re-analyses of this dataset show that all 19 genes support the F3 node that represents Fusarium sensu stricto as defined by F. sambucinum (sexual morph synonym Gibberella pulicaris). The backbone of the phylogeny is resolved by the concatenated alignment, but only six of the 19 genes fully support the F1 node, representing the broad circumscription of Fusarium. Furthermore, a re-analysis of the concatenated dataset revealed alternate topologies in different phylogenetic algorithms, highlighting the deep divergence and unresolved placement of various Nectriaceae lineages proposed as members of Fusarium. Species of Fusarium s. str. are characterised by Gibberella sexual morphs, asexual morphs with thin- or thick-walled macroconidia that have variously shaped apical and basal cells, and trichothecene mycotoxin production, which separates them from other fusarioid genera. Here we show that the Wollenweber concept of Fusarium presently accounts for 20 segregate genera with clear-cut synapomorphic traits, and that fusarioid macroconidia represent a character that has been gained or lost multiple times throughout Nectriaceae. Thus, the very broad circumscription of Fusarium is blurry and without apparent synapomorphies, and does not include all genera with fusarium-like macroconidia, which are spread throughout Nectriaceae (e.g., Cosmosporella, Macroconia, Microcera). In this study four new genera are introduced, along with 18 new species and 16 new combinations. These names convey information about relationships, morphology, and ecological preference that would otherwise be lost in a broader definition of Fusarium. To assist users to correctly identify fusarioid genera and species, we introduce a new online identification database, Fusarioid-ID, accessible at www.fusarium.org. The database comprises partial sequences from multiple genes commonly used to identify fusarioid taxa (act1, CaM, his3, rpb1, rpb2, tef1, tub2, ITS, and LSU). In this paper, we also present a nomenclator of names that have been introduced in Fusarium up to January 2021 as well as their current status, types, and diagnostic DNA barcode data. In this study, researchers from 46 countries, representing taxonomists, plant pathologists, medical mycologists, quarantine officials, regulatory agencies, and students, strongly support the application and use of a more precisely delimited Fusarium (= Gibberella) concept to accommodate taxa from the robust monophyletic node F3 on the basis of a well-defined and unique combination of morphological and biochemical features. This F3 node includes, among others, species of the F. fujikuroi, F. incarnatum-equiseti, F. oxysporum, and F. sambucinum species complexes, but not species of Bisifusarium [F. dimerum species complex (SC)], Cyanonectria (F. buxicola SC), Geejayessia (F. staphyleae SC), Neocosmospora (F. solani SC) or Rectifusarium (F. ventricosum SC). The present study represents the first step to generating a new online monograph of Fusarium and allied fusarioid genera (www.fusarium.org)
Mortalität, gesundheitsbezogene Lebensqualität und Funktionalität nach proximaler Oberschenkelfraktur und ihre Einflussfaktoren in der 5-Jahres-Nachuntersuchung
Die proximale Femurfraktur ist durch eine hohe Inzidenz mit stetig steigenden Fallzahlen aufgrund des demographischen Wandels mit älter werdender Bevölkerungsstruktur gekennzeichnet. Neben einer hohen Mortalitätsrate geht die proximale Femurfraktur mit einer reduzierten gesundheitsbezogenen Lebensqualität und Funktionalität einher. In die prospektiv angelegte Studie wurden 402 Patienten in der Klinik für Orthopädie und Unfallchirurgie des UKGM Standort Marburg inkludiert. Das Durchschnittsalter des überwiegend weiblichen Patientenkollektivs lag zum Zeitpunkt der Rekrutierung bei 81 Jahren. Die zum Zeitpunkt der Aufnahme, der Entlassung, nach 6 Monaten und nach 12 Monaten durchgeführten Erhebungen wurden in der vorliegenden Arbeit durch eine 5-Jahres-Follow-up-Untersuchung ergänzt. Durch die gewonnenen Daten konnten die 5-Jahres-Mortalität sowie Langzeitergebnisse der gesundheitsbezogenen Lebensqualität und Funktionalität nach proximaler Femurfraktur bestimmt werden.
Die 5-Jahres-Mortalität nach proximaler Femurfraktur liegt bei 62%. Unabhängige Risikofaktoren für eine erhöhte 5-Jahres-Mortalität sind höheres Lebensalter (p [ 0,001), männliches Geschlecht (p = 0,002), kognitive Defizite bei Aufnahme (p = 0,002), eingeschränkte Funktionalität vor Frakturereignis (p = 0,024), vorbestehende Komorbiditäten (p = 0,033) und das Auftreten eines postoperativen Delirs (p = 0,008). Zur Reduktion der Mortalität nach proximaler Femurfraktur ist der Erhalt der Selbstständigkeit und Funktionalität der Patienten im höheren Lebensalter anzustreben. Während des stationären Aufenthaltes sollte ein postoperatives Delir bestmöglich verhindert werden oder schnellstmöglich diagnostiziert und therapiert werden. Eine entsprechende Schulung des Personals und interdisziplinäre Behandlung der vulnerablen Patientengruppe erscheint essentiell. Nach Möglichkeit sollte dem Akutaufenthalt eine Rehabilitation angeschlossen werden und das Entlassungsmanagement entsprechend frühzeitig initiiert und optimiert werden.
Die 5-Jahres-Nachuntersuchung wurde bei 134 der 152 ĂĽberlebenden Patienten durchgefĂĽhrt. Der weibliche Anteil des im Durchschnitt 83 Jahre alten Patientenkollektivs lag bei 81%.
Die Beurteilung der gesundheitsbezogenen Lebensqualität erfolgte anhand des EQ5D- Index. Dieser war 5 Jahre nach proximaler Femurfraktur (0,66; CI 0,61-0,72) deutlich niedriger als die der über 65 Jahre alten deutschen Allgemeinbevölkerung (0,87; CI 0,86-0,89). Signifikant niedrigere HRQOL fand sich bei Pflegeheimbewohnern (bereits vor OP p = 0,037; nach 5 Jahren p [ 0,001) sowie funktionell (Barthel-Index p = 0,001) und kognitiv (MMST p = 0,050) eingeschränkten, multimorbiden (ASA-Score p = 0,049; CCS p = 0,048) und älteren (p = 0,023) Patienten. Eine mögliche Depression (GDS p = 0,022) oder ein Delir (DRS p = 0,049) gingen ebenfalls mit einer niedrigeren HRQOL einher, während eine Totalendoprothese als OP-Verfahren eine positive Beeinflussung anzeigte (p = 0,048). Ein unabhängiger Einfluss auf den EQ5D-Index ergab sich in der bivariaten Regressionsanalyse für den Barthel-Index (p = 0,018). Der Erhalt der Funktionalität ist als elementar für eine langfristig bessere gesundheitsbezogene Lebensqualität einzustufen.
Die Funktionalität gemessen am Barthel-Index erreichte nach dem Tiefpunkt direkt postoperativ bereits nach 6 bis 12 Monaten wieder annähernd das präoperative Niveau und nahm im weiteren Verlauf wieder ab. Nach dem unmittelbar durch die Operation bedingten Abnahme der Funktionalität ist die Abnahme über den Langzeitverlauf durch das zunehmende Alter und mögliche begleitend auftretende Komorbiditäten bedingt. Das nach 6 Monaten festgestellte gute Potential zur Wiedererlangung der Funktionalität und Selbstständigkeit untermauert die Relevanz einer frühen postoperativen Mobilisierung sowie das Anschließen einer Rehabilitation. Ein signifikant schlechteres Outcome der Funktionalität konnte bei Pflegeheimbewohnern (p [ 0,001) oder nach Entlassung in eine pflegerische Einrichtung (p [ 0,001), höherem Patientenalter (p = 0,002), höherem ASA-Score (p = 0,001) und Charlson-Komorbiditäts-Index (p = 0,018), kognitiven Defiziten (p [ 0,001), beim möglichen Vorliegen einer Depression (p = 0,029) oder eines Delirs (p = 0,002) sowie das Auftreten von Typ II Komplikationen (p [ 0,001) festgestellt werden. Ein besserer Funktionsstatus zeigte sich nach TEP als OP-Verfahren (p = 0,012). In der multivariaten Analyse verblieben das Alter (p = 0,020), kognitive Defizite (p [ 0,001), ein niedriger Barthel-Index vor Frakturereignis (p [ 0,001) und das Auftreten von Typ II Komplikationen (p = 0,001) als unabhängige Einflussfaktoren. Kognitive Defizite sind generell mit einer eingeschränkten Funktionalität vergesellschaftet. Nach proximaler Femurfraktur gehen diese mit einem signifikant höheren Funktionsverlust einher, weshalb diesem Krankheitsbild zusätzliche Aufmerksamkeit zukommen sollte. Typ-II-Komplikationen sollten möglichst vermieden oder frühzeitig erkannt und behandelt werden um eine langfristige Einschränkung der Funktionalität zu vermeiden
Holocarpic oomycete parasitoids of red algae are not Olpidiopsis
Olpidiopsis is a genus of obligate holocarpic endobiotic oomycetes. Most of the species classified in the genus are known only from their morphology and life cycle, and a few have been examined for their ultrastructure or molecular phylogeny. However, the taxonomic placement of all sequenced species is provisional, as no sequence data are available for the type species, O. saprolegniae, to consolidate the taxonomy of species currently placed in the genus. Thus, efforts were undertaken to isolate O. saprolegniae from its type host, Saprolegnia parasitica and to infer its phylogenetic placement based on 18S rDNA sequences. As most species of Olpidiopsis for which sequence data are available are from rhodophyte hosts, we have also isolated the type species of the rhodophyte-parasitic genus Pontisma, P. lagenidioides and obtained partial 18S rDNA sequences. Phylogenetic reconstructions in the current study revealed that O. saprolegniae from Saprolegnia parasitica forms a monophyletic group with a morphologically similar isolate from S. ferax, and a morphologically and phylogenetically more divergent species from S. terrestris. However, they were widely separated from a monophyletic, yet unsupported clade containing P. lagenidioides and red algal parasites previously classified in Olpidiopsis. Consequently, all holocarpic parasites in red algae should be considered to be members of the genus Pontisma as previously suggested by some researchers. In addition, a new species of Olpidiopsis, O. parthenogenetica is introduced to accommodate the pathogen of S. terrestris
High Diversity Revealed in Leaf-Associated Protists (Rhizaria: Cercozoa) of Brassicaceae
The largest biological surface on earth is formed by plant leaves. These leaf surfaces are colonized by a specialized suite of leaf-inhabiting microorganisms, recently termed phyllosphere microbiome. Microbial prey, however, attract microbial predators. Protists in particular have been shown to structure bacterial communities on plant surfaces, but virtually nothing is known about the community composition of protists on leaves. Using newly designed specific primers targeting the 18S rDNA gene of Cercozoa, we investigated the species richness of this common protist group on leaves of four Brassicaceae species from two different locations in a cloning-based approach. The generated sequences revealed a broad diversity of leaf-associated Cercozoa, mostly bacterial feeders, but also including known plant pathogens and a taxon of potential endophytes that were recently described as algal predators in freshwater systems. This initial study shows that protists must be regarded as an integral part of the microbial diversity in the phyllosphere of plants
Phylogeny and cultivation of the holocarpic oomycete Diatomophthora perforans comb. nov., an endoparasitoid of marine diatoms
Oomycetes infecting diatoms are biotrophic parasitoids and live in both marine and freshwater environments. They are ubiquitous, but the taxonomic affinity of many species remains unclear and the majority of them have not been studied for their molecular phylogeny. Only recently, the phylogenetic and taxonomic placement of some diatom-infecting, early-diverging oomycetes was resolved, including the genera Ectrogella, Miracula, Olpidiopsis, and Pontisma. A group of holocarpic diatom parasitoids with zoospores swarming within the sporangium before release were found to be unrelated to the known genera with diatom-infecting species, and were re-classified to a new genus, Diatomophthora. However, about a dozen species of holocarpic diatom parasitoids with unclear affinity remained unsequenced, which includes a commonly occurring species so far identified as Ectrogella perforans. However, this assignment to Ectrogella is doubtful, as the species was not reported to feature a clear-cut diplanetism, a hallmark of Ectrogella s. str. and the whole class Saprolegniomycetes. It was the aim of the current study to clarify the phylogenetic affinities of the species and if the rather broad host range reported is correct or a reflection of cryptic species. By targeted screening, the parasitoid was rediscovered from Helgoland Roads, North Sea and Oslo Fjord, Southern Norway and investigated for its phylogenetic placement using small ribosomal subunit (18S) sequences. Stages of its life cycle on different marine diatoms were described and its phylogenetic placement in the genus Diatomophthora revealed. A stable host-parasite axenic culture from single spore strains of the parasitoid were established on several strains of Pleurosigma intermedium and Coscinodiscus concinnus. These have been continuously cultivated along with their hosts for more than 2 years, and cultural characteristics are reported. Cross-infection trials revealed the transferability of the strains between hosts under laboratory conditions, despite some genetic distance between the pathogen strains. Thus, we hypothesise that D. perforans might be in the process of active radiation to new host species