TotalSegmentator: robust segmentation of 104 anatomical structures in CT images

We present a deep learning segmentation model that can automatically and robustly segment all major anatomical structures in body CT images. In this retrospective study, 1204 CT examinations (from the years 2012, 2016, and 2020) were used to segment 104 anatomical structures (27 organs, 59 bones, 10 muscles, 8 vessels) relevant for use cases such as organ volumetry, disease characterization, and surgical or radiotherapy planning. The CT images were randomly sampled from routine clinical studies and thus represent a real-world dataset (different ages, pathologies, scanners, body parts, sequences, and sites). The authors trained an nnU-Net segmentation algorithm on this dataset and calculated Dice similarity coefficients (Dice) to evaluate the model's performance. The trained algorithm was applied to a second dataset of 4004 whole-body CT examinations to investigate age dependent volume and attenuation changes. The proposed model showed a high Dice score (0.943) on the test set, which included a wide range of clinical data with major pathologies. The model significantly outperformed another publicly available segmentation model on a separate dataset (Dice score, 0.932 versus 0.871, respectively). The aging study demonstrated significant correlations between age and volume and mean attenuation for a variety of organ groups (e.g., age and aortic volume; age and mean attenuation of the autochthonous dorsal musculature). The developed model enables robust and accurate segmentation of 104 anatomical structures. The annotated dataset (https://doi.org/10.5281/zenodo.6802613) and toolkit (https://www.github.com/wasserth/TotalSegmentator) are publicly available.Comment: Accepted at Radiology: Artificial Intelligenc

Das vaskuläre Trauma: Analyse der Versorgungsrealität in einer deutschlandweiten Umfrage

Hintergrund und Ziel der Arbeit Die vaskuläre Beteiligung im Rahmen von Traumen ist selten. Für die Versorgung der Verletzungen gibt es nur wenige konkrete Handlungsempfehlungen, sodass von einer großen Varianz auszugehen ist. Ziel der vorliegenden Umfrage war die Statuserhebung der aktuellen Versorgungsrealität des Gefäßtraumas in Deutschland sowie die Eruierung des Bedarfs und der Form von entsprechenden Fortbildungsangeboten. Material und Methoden Es wurde eine Online-Umfrage über SurveyMonkey® mit den Mitgliedern der Gesellschaft für Gefäßchirurgie und Gefäßmedizin (DGG) durchgeführt. Ergebnisse An der Umfrage haben sich 10,6 % der angeschriebenen Mitglieder der DGG beteiligt. Hieraus ergab sich, dass die meisten Kliniken 5–10 traumatische Gefäßverletzungen pro Jahr versorgen, wobei die höchsten Behandlungszahlen erwartungsgemäß in den überregionalen Traumazentren erreicht werden. Die Versorgung des Gefäßtraumas ist nicht einheitlich, sondern findet abhängig von der anatomischen Lokalisation durch unterschiedliche Fachabteilungen statt. Kliniken für Gefäßchirurgie sind selten an der Versorgung beteiligt. Bei den meisten Befragten bestand der Wunsch nach Fortbildungen zum Erlernen von gefäßtraumatologischen Techniken. Diskussion Gefäßchirurgische Kliniken sind nach den vorliegenden Umfrageergebnissen selten an der Versorgung des vaskulären Traumas beteiligt. Mögliche Erklärungen hierfür liegen in lokalen und infrastrukturellen Gegebenheiten. Eine aktive Einbindung von gefäßchirurgisch ausgebildeten Ärztinnen und Ärzten in die Diagnostik und Therapie der vaskulären Traumata ist wünschenswert und sollte aktiv angeboten werden. Das Erlernen der hierfür notwendigen Techniken kann beispielsweise im Rahmen praktischer Kurse stattfinden

soil2data: Konzept für ein mobiles Feldlabor zur Nährstoffanalytik

Für eine Optimierung des Düngemitteleinsatzes in der Pflanzenproduktion sind Kenntnisse über den kleinräumigen Nährstoffstatus einer Ackerfläche eine wesentliche Voraussetzung für eine Entscheidungsgrundlage bei der Düngung. Ein mobiles Feldlabor eröffnet die Möglichkeit eine parallele Bodenbeprobung und Bodennährstoffanalyse direkt auf dem Feld durchzuführen. Neben den Vorteilen einer schnellen Datenverfügbarkeit und dem entfallenden Bodenmaterialtransport zum Labor, bildet es eine zukünftige Grundlage für neue Anwendungsoptionen, z.B. eine hohe Beprobungsdichte oder eine dynamische Anpassung der Bodenbeprobung bzw. Beprobungslinie während der Arbeit auf dem Feld. Eine innovative Schlüsselkomponente ist dabei das NUTRI-STAT ISFET-Sensormodul. Dieses ist speziell für die Bodennährstoff-Analytik entwickelt und für das Projekt soil2data für die Phosphor-Messung weiterentwickelt worden

Structural basis for potency differences between GDF8 and GDF11.

BACKGROUND: Growth/differentiation factor 8 (GDF8) and GDF11 are two highly similar members of the transforming growth factor β (TGFβ) family. While GDF8 has been recognized as a negative regulator of muscle growth and differentiation, there are conflicting studies on the function of GDF11 and whether GDF11 has beneficial effects on age-related dysfunction. To address whether GDF8 and GDF11 are functionally identical, we compared their signaling and structural properties. RESULTS: Here we show that, despite their high similarity, GDF11 is a more potent activator of SMAD2/3 and signals more effectively through the type I activin-like receptor kinase receptors ALK4/5/7 than GDF8. Resolution of the GDF11:FS288 complex, apo-GDF8, and apo-GDF11 crystal structures reveals unique properties of both ligands, specifically in the type I receptor binding site. Lastly, substitution of GDF11 residues into GDF8 confers enhanced activity to GDF8. CONCLUSIONS: These studies identify distinctive structural features of GDF11 that enhance its potency, relative to GDF8; however, the biological consequences of these differences remain to be determined

Key stages in mammary gland development: The mammary end bud as a motile organ

In the rodent, epithelial end buds define the tips of elongating mammary ducts. These highly motile structures undergo repeated dichotomous branching as they aggressively advance through fatty stroma and, turning to avoid other ducts, they finally cease growth leaving behind the open, tree-like framework on which secretory alveoli develop during pregnancy. This review identifies the motility of end buds as a unique developmental marker that represents the successful integration of systemic and local mammotrophic influences, and covers relevant advances in ductal growth regulation, extracellular matrix (ECM) remodeling, and cell adhesion in the inner end bud. An unexpected growth-promoting synergy between insulin-like growth factor-1 and progesterone, in which ducts elongate without forming new end buds, is described as well as evidence strongly supporting self-inhibition of ductal elongation by end-bud-secreted transforming growth factor-β acting on stromal targets. The influence of the matrix metalloproteinase ECM-remodeling enzymes, notably matrix metalloproteinase-2, on end bud growth is discussed in the broader context of enzymes that regulate the polysaccharide-rich glycosaminoglycan elements of the ECM. Finally, a critical, motility-enabling role for the cellular architecture of the end bud is identified and the contribution of cadherins, the netrin/neogenin system, and ErbB2 to the structure and motility of end buds is discussed

H-Ras Activation Promotes Cytoplasmic Accumulation and Phosphoinositide 3-Oh Kinase Association of β-Catenin in Epidermal Keratinocytes

The mechanisms underlying downregulation of the cadherin/catenin complexes and β-catenin signaling during tumor progression are not fully understood. We have analyzed the effect of oncogenic H-Ras on E-cadherin/catenin complex formation/stabilization and β-catenin distribution in epidermal keratinocytes. Microinjection or stable expression of V12Ras into keratinocytes promotes the loss of E-cadherin and α-catenin and relocalization of β-catenin to the cytoplasm and nucleus. Moreover, these effects are dependent on PI3K (phosphoinositide 3-OH kinase) activity. Interestingly, a strong association of p85α and p110α subunits of PI3K with β-catenin is induced in V12Ras-expressing keratinocytes, and in vitro binding assays show a direct interaction between β-catenin and p85α. Overexpression of either V12Ras or constitutively active p110α induces metabolic stabilization of β-catenin and promotes its accumulation in cytoplasmic and nuclear pools. In addition, the interaction of β-catenin with the adenomatous polyposis coli protein is blocked in V12Ras and p110α transformants though no changes in glycogen synthase kinase 3 β activity could be detected. Nevertheless, in V12Ras transformants the in vivo phosphorylation of β-catenin in Ser residues is strongly decreased. These results indicate that H-Ras activation induces the relocalization and cytoplasmic stabilization of β-catenin by a mechanism involving its interaction with PI3K

Key stages in mammary gland development: The cues that regulate ductal branching morphogenesis

Part of how the mammary gland fulfills its function of producing and delivering adequate amounts of milk is by forming an extensive tree-like network of branched ducts from a rudimentary epithelial bud. This process, termed branching morphogenesis, begins in fetal development, pauses after birth, resumes in response to estrogens at puberty, and is refined in response to cyclic ovarian stimulation once the margins of the mammary fat pad are met. Thus it is driven by systemic hormonal stimuli that elicit local paracrine interactions between the developing epithelial ducts and their adjacent embryonic mesenchyme or postnatal stroma. This local cellular cross-talk, in turn, orchestrates the tissue remodeling that ultimately produces a mature ductal tree. Although the precise mechanisms are still unclear, our understanding of branching in the mammary gland and elsewhere is rapidly improving. Moreover, many of these mechanisms are hijacked, bypassed, or corrupted during the development and progression of cancer. Thus a clearer understanding of the underlying endocrine and paracrine pathways that regulate mammary branching may shed light on how they contribute to cancer and how their ill effects might be overcome or entirely avoided