Safety evaluation on ammonia-fueled ship : gas dispersion analysis through vent mast

The maritime industry is exploring ammonia as an alternative fuel to reduce greenhouse gas emissions. However, the high toxicity of ammonia poses significant safety challenges for onboard handling and storage. This study investigates ammonia dispersion and toxicity levels from vent mast releases on ships, aiming to enhance safety measures for future ammonia-fueled vessels. Using CFD analysis on a 31,000-dwt general cargo ship model, the research examines various release scenarios, considering regulatory requirements, vent mast design, and environmental conditions. Results show that direct ammonia release from the vent mast poses fatal risks to the crew in the accommodation area and on adjacent ships, regardless of current regulatory stipulations. The study recommends installing an ammonia-catching system to reduce concentrations to safe levels of 30 ppm before release. These findings offer crucial insights for improving the safety of using ammonia as marine fuel through risk assessment and management

Molecular characterization of duodenal CCK-containing enteroendocrine cells

The enteroendocrine system orchestrates the physiological responses to food intake. Enteroendocrine (EEC) cells sense nutrients and secrete hormones in response to them. There are more than fifteen subtypes of EEC cells that secrete a range of gut hormones, which play a pivotal role in the co-ordination of food digestion, control of appetite and the regulation of glucose homeostasis. I-cells represent a subset of enteroendocrine cells that are mainly localized in the proximal small intestine(duodenum) and release cholecystokinin (CCK) in response to nutrients (mainly fat). CCK is the archetypal satiety hormone that transmits anorectic signals to the brain via a gut-to-brain signalling pathway, mediated by vagal afferent neurons. Additionally,CCK has a key pro-digestive function by inhibiting gastric emptying and stimulating the release of bile from the gallbladder and the secretion of pancreatic enzymes. Until recently, the characterization of enteroendocrine cells has been restricted to cell line models. The development of transgenic animal models with genetically tagged enteroendocrine cells enabled us to study native enteroendocrine cells. We used a transgenic mouse model that express enhanced Green Fluorescence Protein (eGFP) under the control of Cck gene promoter, in order to study native I-cells. Initially, we developed a robust protocol for the isolation of duodenal CCK-containing cells that represent the typical I-cells. By using semi-quantitative RT-PCR, we revealed that duodenal I-cells contain mRNA transcripts encoding key long chain fatty acid (LCFA), short chain fatty acid (SCFA) and endocannabinoid receptors. We also analysed the gut hormone content of duodenal I-cells and found that a subpopulation of CCK-containing cells co-express CCK with proglucagon, glucose-dependent insulinotropic peptide (GIP), Peptide YY (PYY), neurotensin, secretin and surprisingly the orexigenic hormone ghrelin. Our findings suggest that duodenal I-cells have the capacity to sense LCFA, SCFA, fatty acid lipid amides and intestinal endocannabinoid peptides. They also indicate that there is a significant overlap between I-cells and other subsets of EEC cells and that a subset of I-cells may co-release CCK with other gut hormones.Το εντεροενδοκρινές σύστημα συντονίζει τη φυσιολογική απάντηση του οργανισμού που ακολουθεί την λήψη τροφής. Τα εντεροενδοκρινή κύτταρα αισθάνονται/αναγνωρίζουν τα θρεπτικά συστατικά που βρίσκονται στον εντερικό αυλό και απαντούν σε αυτά τα ερεθίσματα εκκρίνοντας ορμόνες. Υπάρχουν πάνω από 15 τύποι εντεροενδοκρινών κυττάρων που εκκρίνουν μια σειρά από εντερικές ορμόνες, οι οποίες επιτελούν κυριάρχο ρόλο στο συντονισμό της πέψης του φαγητού, στον έλεγχο της όρεξης και στη ρύθμιση των επιπέδων γλυκόζης στο αίμα. Tα I-κύτταρα αποτελούν ένα τύπο εντεροενδοκρινών κυττάρων που κυρίως εντοπίζονται στο εγγύς λεπτό έντερο (δωδεκαδάκτυλο) και εκκρίνουν την ορμόνη χολοκυστοκινίνη όταν διεγείρονται από θρεπτικά συστατικά (κυρίως λίπη). H χολοκυστοκινίνη θεωρείται ως η αρχετυπική ορμόνη που δημιουργεί αίσθημα κορεσμού μετά το φαγητό και διαμεσολαβεί ανορεξικά σήματα από το έντερο προς τον εγκέφαλο, μέσω του πνευμονογαστρικού νεύρου. Επιπλέον, η χολοκυστοκινίνη διευκολύνει την πέψη παρατείνοντας το χρόνο παραμονής της τροφής στο στόμαχο ενώ παράλληλα διεγείρει την απελευθέρωση της χολής από τη χοληδόχο κύστη και την έκκριση των παγκρεατικών ενζύμων. Μέχρι πρόσφατα, οι προσπάθειες για το χαρακτηρισμό των εντεροενδοκρινών κυττάρων περιορίζονταν στην μελέτη κυτταρικών σειρών-μοντέλων. Η ανάπτυξη διαγονιδιακών μοντέλων ζώων με γενετικά σημασμένα εντεροενδοκρινή κύτταρα μας δίνει τη δυνατότητα μελέτης των φυσιολογικών εντεροενδοκρινών κυττάρων. Για την έρευνά μας, χρησιμοποιήσαμε ένα διαγονιδιακό μοντέλο μυός/ποντικού το οποίο εκφράζει την πράσινη φθορίζουσα πρωτείνη eGFP κάτω από τον έλεγχο του υποκινητή του γονιδίου της χολοκυστοκινίνης με σκοπό να μελετήσουμε τα Ι-κύτταρα. Αρχικά, αναπτύξαμε ένα αξιόπιστο πρωτόκολλο για την απομόνωση των κυττάρων χολοκυστοκινίνης του δωδεκαδακτύλου που αποτελούν τον πληθυσμό των τυπικών Ι-κυττάρων. Χρησιμοποιώντας την ημι-ποσοτική μέθοδο RT-PCR, δείξαμε πως τα δωδεκαδακτυλικά Ι-κύτταρα περιέχουν mRNA μετάγραφα τα οποία κωδικοποιούν την έκφραση πρωτεϊνών υποδοχέων των μακράς αλύσου λιπαρών οξέων, κοντής αλύσου λιπαρών οξέων καθώς και ενδοκανναβινοειδών πεπτιδίων. Παράλληλα, αναλύσαμε το ορμονικό περιεχόμενο των δωδεκαδακτυλικών Ι-κυττάρων ανακαλύπτοντας ότι ένας υποπληθυσμός κυττάρων χολοκυστοκινίνης συν-εκφράζει μαζί με τη χολοκυστοκινίνη και άλλες εντερικές ορμόνες όπως η προγλουκαγόνη, το εξαρτώμενο από τη γλυκόζη ινσουλινοτροπικό πεπτίδιο, το πεπτίδιο ΥΥ, η νευροτενσίνη, η εκκριτίνη/σεκριτίνη και παραδόξως η ορμόνη γκρελίνη- η μοναδική από τις εντερικές ορμόνες που διεγείρει την όρεξη για τη λήψη τροφής. Τα ευρήματά μας συνηγορούν στη δυνατότητα των κυττάρων χολοκυστοκινίνης του δωδεκαδακτύλου να αναγνωρίζουν λιπαρά οξέα μακράς και κοντής αλύσου, προιοντα μεταβολισμού των λιπαρών οξέων καθώς και εντερικά ενδοκανναβινοειδή πεπτίδια. Επιπλέον, υποστηρίζουν την θεώρηση πως υπάρχει αλληλοεπικάλυψη ανάμεσα στους διάφορους τύπους των εντεροενδοκρινών κυττάρων και ότι είναι πιθανό ένας υποπληθυσμός των Ι-κυττάρων να εκκρίνει χολοκυστοκινίνη σύγχρονα με άλλες εντερικές ορμόνες

Patient-Derived Organoids: The Beginning of a New Era in Ovarian Cancer Disease Modeling and Drug Sensitivity Testing

Ovarian cancer (OC) is the leading cause of death from gynecological malignancies. Despite great advances in treatment strategies, therapeutic resistance and the gap between preclinical data and actual clinical efficacy justify the necessity of developing novel models for investigating OC. Organoids represent revolutionary three-dimensional cell culture models, deriving from stem cells and reflecting the primary tissue’s biology and pathology. The aim of the current review is to study the current status of mouse- and patient-derived organoids, as well as their potential to model carcinogenesis and perform drug screenings for OC. Herein, we describe the role of organoids in the assessment of high-grade serous OC (HGSOC) cells-of-origin, illustrate their use as promising preclinical OC models and highlight the advantages of organoid technology in terms of disease modelling and drug sensitivity testing

Duodenal enteroendocrine I-cells contain mRNA transcripts encoding key endocannabinoid and fatty acid receptors

Enteroendocrine cells have a critical role in regulation of appetite and energy balance. I-cells are a subtype of enteroendocrine cells localized in duodenum that release cholecystokinin in response to ingested fat and amino-acids. Despite their potentially pivotal role in nutrient sensing and feeding behaviour, native I-cells have previously been difficult to isolate and study. Here we describe a robust protocol for the isolation and characterization of native duodenal I-cells and additionally, using semi-quantitative RT-PCR we determined that mouse duodenal I-cells contain mRNA transcripts encoding key fatty acid and endocannabinoid receptors including the long chain fatty acid receptors GPR40/FFAR1, GPR120/O3FAR1; short chain fatty acid receptors GPR41/FFAR3 and GPR43/FFAR2; the oleoylethanolamide receptor GPR119 and the classic endocannabinoid receptor CB1. These data suggest that I-cells sense a wide range of gut lumen nutrients and also have the capacity to respond to signals of fatty-acid derivatives or endocannabinoid peptides

Mladi ambasadorji v boju proti dopingu

Hepatosteatosis is associated with the development of both hepatic insulin resistance and Type 2 diabetes. Hepatic expression of Cd36, a fatty acid transporter, is enhanced in obese and diabetic murine models and human nonalcoholic fatty liver disease, and thus it correlates with hyperinsulinemia, steatosis, and insulin resistance. Here, we have explored the effect of hyperinsulinemia on hepatic Cd36 expression, development of hepatosteatosis, insulin resistance, and dysglycemia. A 3-week sucrose-enriched diet was sufficient to provoke hyperinsulinemia, hepatosteatosis, hepatic insulin resistance, and dysglycemia in CBA/J mice. The development of hepatic steatosis and insulin resistance in CBA/J mice on a sucrose-enriched diet was paralleled by increased hepatic expression of the transcription factor Ppar gamma and its target gene Cd36 whereas that of genes implicated in lipogenesis, fatty acid oxidation, and VLDL secretion was unaltered. Additionally, we demonstrate that insulin, in a Ppar gamma-dependent manner, is sufficient to directly increase Cd36 expression in perfused livers and isolated hepatocytes. Mouse strains that display low insulin levels, i.e. C57BL6/J, and/or lack hepatic Ppar gamma, i.e. C3H/HeN, do not develop hepatic steatosis, insulin resistance, or dysglycemia on a sucrose-enriched diet, suggesting that elevated insulin levels, via enhanced CD36 expression, provoke fatty liver development that in turn leads to hepatic insulin resistance and dysglycemia. Thus, our data provide evidence for a direct role for hyperinsulinemia in stimulating hepatic Cd36 expression and thus the development of hepatosteatosis, hepatic insulin resistance, and dysglycemia

Duodenal CCK cells from male mice express multiple hormones including ghrelin

AbstractEnteroendocrine (EEC) cells have a pivotal role in intestinal nutrient sensing and release hormones that orchestrate food digestion and regulate appetite. EEC cells are found scattered throughout the intestine and have typically been classified based on the primary hormone they contain. I cells represent a subset of EEC cells that secrete cholecystokinin (CCK) and are mainly localized to the duodenum. Recent studies have shown that I cells express mRNAs encoding several gut hormones. In this study, we investigated the hormonal profile of murine fluorescence-activated cell sorting-sorted duodenal I cells using semiquantitative RT-PCR, liquid chromatography tandem mass spectrometry, and immunostaining methods. We report that I cells are enriched in mRNA transcripts encoding CCK and also other key gut hormones, including neurotensin, glucose-dependent insulinotropic peptide (GIP), secretin, peptide YY, proglucagon, and ghrelin (Ghrl). Furthermore, liquid chromatography tandem mass spectrometry analysis of fluorescence-activated cell sorting-purified I cells and immunostaining confirmed the presence of these gut hormones in duodenal I cells. Immunostaining highlighted that subsets of I cells in both crypts and villi coexpress differential amounts of CCK, Ghrl, GIP, or peptide YY, indicating that a proportion of I cells contain several hormones during maturation and when fully differentiated. Our results reveal that although I cells express several key gut hormones, including GIP or proglucagon, and thus have a considerable overlap with classically defined K and L cells, approximately half express Ghrl, suggesting a potentially important subset of duodenal EEC cells that require further consideration.</jats:p

Unraveling the Role of Histone Variant CENP-A and Chaperone HJURP Expression in Thymic Epithelial Neoplasms

Background: Recent advances demonstrate the role of chromatin regulators, including histone variants and histone chaperones, in cancer initiation and progression. Methods: Histone H3K4me3, histone variant centromere protein (CENP-A) and histone chaperones Holliday junction recognition protein (HJURP) as well as DAXX expression were examined immunohistochemically in 95 thymic epithelial tumor (TET) specimens. Our results were compared with the expression profile of DAXX, HJURP and CENP-A in gene expression profiling interactive analysis (GEPIA2). Results: The lymphocyte-poor B3- and C-type TETs were more frequently DAXX negative (p = 0.043). B3 and C-Type TETs showed higher cytoplasmic and nuclear CENP-A (p = 0.007 and p = 0.002) and higher cytoplasmic HJURP H-score (p &lt; 0.001). Higher nuclear CENP-A and cytoplasmic HJURP expression was associated with advanced Masaoka&ndash;Koga stage (p = 0.048 and p &lt; 0.001). A positive correlation between HJURP and CENP-A was also observed. The presence of cytoplasmic CENP-A expression was correlated with a favorable overall survival (p = 0.03). CENP-A overexpression in survival analysis of TCGA TETs showed similar results. H3K4me3 expression was not associated with any clinicopathological parameters. Conclusions: Our results suggest a significant interaction between CENP-A and HJURP in TETs. Moreover, we confirmed the presence of a cytoplasmic CENP-A immunolocalization, suggesting also a possible favorable prognostic value of this specific immunostaining pattern

Semi-quantitative RT-PCR on amplified cDNA from sorted cells validates I-cells enriched mRNA transcripts.

<p>Semi-quantitative RT-PCR analysis using amplified cDNA from eGFP+ and eGFP− cells. Left panel: eGFP+ cells were highly enriched in mRNA transcripts encoding eGFP and CCK whereas these transcripts were not detected in eGFP− cells. eGFP− cells were enriched in mRNA transcripts encoding AKP3 and MUC2, markers of enterocytes and goblet cells respectively. Right panel: Validation of Gpr40/Ffar1, Gpr120/O3far1, Gpr41/Ffar3, Gpr43/Ffar2, Gpr119 and CB1 mRNA transcripts enrichment in I-cells. 18S rRNA was used as a loading control. PCR products were amplified simultaneously, using different number of cycles (low-for lower number of cycles and high-for higher number of cycles). Equal volumes of each reaction were run on the same 2% agarose gel. L declares Hyperladder V (50–250 bp, Bioline, UK). Asterisk indicates primer dimers.</p

I-cells contain GPR40, GPR120, GPR41, GPR43, GPR119 and CB1 mRNA transcripts.

<p>Semi-quantitative RT-PCR analysis revealed that eGFP+ cells (I-cells) were enriched in mRNA transcripts encoding Gpr40/Ffar1, Gpr41/Ffar3, Gpr43/FFAR2, Gpr119 and CB1 whereas Gpr120/O3far1 was enriched in eGFP+ cells, but was also present eGFP− cells; RT-PCR of 18S rRNA confirms that equal amount of cDNA template from eGFP+ and eGFP− cells was used for the analysis. L declares Hyperladder IV (100–1000 bp, Bioline, UK). Asterisk indicates bands representing primer dimers.</p