Replacing middle colic artery arising from the splenic artery-an arterial variety in a patient undergoing total pancreatoduodenectomy.

Knowledge of variations in arterial vascular supply is crucial in HPB and general surgery. Although the arterial configuration of the coeliac trunk and the superior mesenteric artery had been investigated, there are still arterial branching patterns to be described. We herein present the case of an 84-year-old male patient who underwent total pancreatectomy due to a not specified pancreas head tumor with a replacing right hepatic artery according to Michel's classification III and a replacing middle colic artery arising from the splenic artery and running on the ventral side of the pancreas. To the best of our knowledge, this arterial branching pattern has never been described so far. In this case, two arterial variations had been presented with a type III arterial supply according to Michel's classification, and a replacing middle colic artery arising from the SA.

An Automated Electrochemical Flow Platform to Accelerate Library Synthesis and Reaction Optimization.

Automated batch and flow reactors are well-established for high throughput experimentation in both thermal chemistry and photochemistry. However, the development of automated electrochemical platforms is hindered by cell miniaturization challenges in batch and difficulties in designing effective single-pass flow systems. In order to address these issues, we have designed and implemented a new, slug-based automated electrochemical flow platform. This platform was successfully demonstrated for electrochemical C-N cross-couplings of E3 ligase binders with diverse amines (44 examples), which were subsequently transferred to a continuous-flow mode for confirmation and isolation, showing its applicability for medicinal chemistry purposes. To further validate the versatility of the platform, Design of Experiments (DoE) optimization was performed for an unsuccessful library target. This optimization process, fully automated by the platform, resulted in a remarkable 6-fold increase in reaction yield.

Understanding the impact of breathing pattern disorders in difficult-to-treat asthma.

INTRODUCTION: Difficult-to-treat asthma is defined as asthma that is uncontrolled despite high-level treatment or requires such treatment to maintain good control and reduce exacerbations. Breathing pattern disorders (BPD) have been reported as a comorbidity in ~ 24-42% % of patients with difficult-to-treat asthma. This narrative review will assess the association, impact, and management of BPD in difficult-to-treat asthma. AREAS COVERED: We outline current understandings of the nature of difficult-to-treat asthma and BPD. We then review the impact of BPD on difficult-to-treat asthma and Multidisciplinary Team (MDT) approaches to assessing and managing BPD in this patient group. A comprehensive literature search was performed by an asthma specialist MDT including physiotherapists, psychologists, and physicians to create a holistic perspective on this subject. EXPERT OPINION: BPD exerts significant negative impacts across multiple domains in patients with difficult-to treat asthma. There is a need for further observational, interventional, qualitative and quantitative research to develop better diagnosis, treatment, and awareness of the impacts of BPD including health economic analysis. Studies should develop multimodal approaches that better treat both BPD and associated comorbidities within the multimorbidity framework of difficult-to-treat asthma. Recognizing and addressing BPD should be key elements in future difficult-to-treat asthma management guidelines and clinical practice.

What's new in pediatric lower limb reconstruction?

The last years brought many advances relevant to lower limb reconstruction. It feels like guided growth has been looked at from every angle, and still there are new emerging concepts like rotational guided growth waiting to be validated. New hexapod external devices are more accurate and easier to use, and new unilateral fixators allow for more versatile and stable fixation and lengthening. Intramedullary nail lengthening has found its place as a standard procedure for various diagnoses in children and young adults. First results of new and exciting approaches like extramedullary implantable nail lengthening and lengthening plates have been reported. Pharmaceutical treatment has changed the course of certain diseases and must be integrated and considered when making a reconstructive treatment plan. As reconstructive surgery is rapidly advancing so are the technical options for prosthetic fitting, which makes it difficult for caregivers as well as for parents to make the decision between reconstruction and amputation surgery for the most severe cases of congenital deficiencies. This review is highlighting new developments of lower limb reconstruction and is reviewing the current literature.

Building up a model family for inflammations.

The paper presents an approach for overcoming modeling problems of typical life science applications with partly unknown mechanisms and lacking quantitative data: A model family of reaction-diffusion equations is built up on a mesoscopic scale and uses classes of feasible functions for reaction and taxis terms. The classes are found by translating biological knowledge into mathematical conditions and the analysis of the models further constrains the classes. Numerical simulations allow comparing single models out of the model family with available qualitative information on the solutions from observations. The method provides insight into a hierarchical order of the mechanisms. The method is applied to the clinics for liver inflammation such as metabolic dysfunction-associated steatohepatitis or viral hepatitis where reasons for the chronification of disease are still unclear and time- and space-dependent data is unavailable.

Does Timepoint of Surgical Procedure Affect the Outcome in Simultaneous Pancreas-Kidney Transplantation? A Retrospective Single-Center Analysis over 20 Years.

Background: Sleep deprivation and disturbances in circadian rhythms may hinder surgical performance and decision-making capabilities. Solid organ transplantations, which are technically demanding and often begin at uncertain times, frequently during nighttime hours, are particularly susceptible to these effects. This study aimed to assess how transplant operations conducted during daytime versus nighttime influence both patient and graft outcomes and function. Methods: simultaneous pancreas-kidney transplants (SPKTs) conducted at the University Hospital of Leipzig from 1998 to 2018 were reviewed retrospectively. The transplants were categorized based on whether they began during daytime hours (8 a.m. to 6 p.m.) or nighttime hours (6 p.m. to 8 a.m.). We analyzed the demographics of both donors and recipients, as well as primary outcomes, which included surgical complications, patient survival, and graft longevity. Results: In this research involving 105 patients, 43 SPKTs, accounting for 41%, took place in the daytime, while 62 transplants (59%) occurred at night. The characteristics of both donors and recipients were similar across the two groups. Further, the rate of (surgical) pancreas graft-related complications and reoperations (daytime 39.5% versus nighttime 33.9%; p = 0.552) were also not statistically significant between both groups. In this study, the five-year survival rate for patients was comparable for both daytime and nighttime surgeries, with 85.2% for daytime and 86% for nighttime procedures (p = 0.816). Similarly, the survival rates for pancreas grafts were 75% for daytime and 77% for nighttime operations (p = 0.912), and for kidney grafts, 76% during the day compared to 80% at night (p = 0.740), indicating no significant statistical difference between the two time periods. In a multivariable model, recipient BMI > 30 kg/m2, donor age, donor BMI, and cold ischemia time > 15 h were independent predictors for increased risk of (surgical) pancreas graft-related complications, whereas the timepoint of SPKT (daytime versus nighttime) did not have an impact. Conclusions: The findings from our retrospective analysis at a big single German transplant center indicate that SPKT is a reliable procedure, regardless of the start time. Additionally, our data revealed that patients undergoing nighttime transplants have no greater risk of surgical complications or inferior results concerning long-term survival of the patient and graft. However, due to the small number of cases evaluated, further studies are required to confirm these results.

Biomarker screen for efficacy of oncolytic virotherapy in patient-derived pancreatic cancer cultures.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is a tumour entity with unmet medical need. To assess the therapeutic potential of oncolytic virotherapy (OVT) against PDAC, different oncolytic viruses (OVs) are currently investigated in clinical trials. However, systematic comparisons of these different OVs in terms of efficacy against PDAC and biomarkers predicting therapeutic response are lacking. METHODS: We screened fourteen patient-derived PDAC cultures which reflect the intra- and intertumoural heterogeneity of PDAC for their sensitivity to five clinically relevant OVs, namely serotype 5 adenovirus Ad5-hTERT, herpes virus T-VEC, measles vaccine strain MV-NIS, reovirus jin-3, and protoparvovirus H-1PV. Live cell analysis, quantification of viral genome/gene expression, cell viability as well as cytotoxicity assays and titration of viral progeny were conducted. Transcriptome profiling was employed to identify potential predictive biomarkers for response to OV treatment. FINDINGS: Patient-derived PDAC cultures showed individual response patterns to OV treatment. Twelve of fourteen cultures were responsive to at least one OV, with no single OV proving superior or inferior across all cultures. Known host factors for distinct viruses were retrieved as potential biomarkers. Compared to the classical molecular subtype, the quasi-mesenchymal or basal-like subtype of PDAC was found to be more sensitive to H-1PV, jin-3, and T-VEC. Generally, expression of viral entry receptors did not correlate with sensitivity to OV treatment, with one exception: Expression of Galectin-1 (LGALS1), a factor involved in H-1PV entry, positively correlated with H-1PV induced cell killing. Rather, cellular pathways controlling immunological, metabolic and proliferative signaling appeared to determine outcome. For instance, high baseline expression of interferon-stimulated genes (ISGs) correlated with relative resistance to oncolytic measles virus, whereas low cyclic GMP-AMP synthase (cGAS) expression was associated with exceptional response. Combination treatment of MV-NIS with a cGAS inhibitor improved tumour cell killing in several PDAC cultures and cells overexpressing cGAS were found to be less sensitive to MV oncolysis. INTERPRETATION: Considering the heterogeneity of PDAC and the complexity of biological therapies such as OVs, no single biomarker can explain the spectrum of response patterns. For selection of a particular OV, PDAC molecular subtype, ISG expression as well as activation of distinct signaling and metabolic pathways should be considered. Combination therapies can overcome resistance in specific constellations. Overall, oncolytic virotherapy is a viable treatment option for PDAC, which warrants further development. This study highlights the need for personalised treatment in OVT. By providing all primary data, this study provides a rich source and guidance for ongoing developments. FUNDING: German National Science Foundation (Deutsche Forschungsgemeinschaft, DFG), German Cancer Aid (Deutsche Krebshilfe), German National Academic Scholarship Foundation (Studienstiftung des deutschen Volkes), Survival with Pancreatic Cancer Foundation.

Amino-terminally elongated Aß peptides are generated by the secreted metalloprotease ADAMTS4 and deposit in a subset of Alzheimer's disease brains.

AIMS: The aggregation and deposition of amyloid-ß (Aß) peptides in the brain is thought to be the initial driver in the pathogenesis of Alzheimer's disease (AD). Aside from full-length Aß peptides starting with an aspartate residue in position 1, both N-terminally truncated and elongated Aß peptides are produced by various proteases from the amyloid precursor protein (APP) and have been detected in brain tissues and body fluids. Recently, we demonstrated that the particularly abundant N-terminally truncated Aß4-x peptides are generated by ADAMTS4, a secreted metalloprotease that is exclusively expressed in the oligodendrocyte cell population. In this study, we investigated whether ADAMTS4 might also be involved in the generation of N-terminally elongated Aß peptides. METHODS: We used cell-free and cell-based assays in combination with matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF) and electrochemiluminescence sandwich immunoassays to identify and quantify N-terminally elongated Aß peptide variants. Antibodies against these Aß variants were characterised by peptide microarrays and employed for the immunohistochemical analyses of human brain samples. RESULTS: In this study, we discovered additional ADAMTS4 cleavage sites in APP. These were located N-terminal to Asp-(1) in the Aß peptide sequence between residues Glu-(-7) and Ile-(-6) as well as Glu-(-4) and Val-(-3), resulting in the release of N-terminally elongated Aß-6-x and Aß-3-x peptides, of which the latter serve as a component in a promising Aß-based plasma biomarker. Aß-6/-3-40 peptides were detected in supernatants of various cell lines and in the cerebrospinal fluid (CSF), and ADAMTS4 enzyme activity promoted the release of Aß-6/-3-x peptides. Furthermore, by immunohistochemistry, a subset of AD cases displayed evidence of extracellular and vascular localization of N-terminally elongated Aß-6/-3-x peptides. DISCUSSION: The current findings implicate ADAMTS4 in both the pathological process of Aß peptide aggregation and in the early detection of amyloid pathology in AD.

Stroma AReactive Invasion Front Areas (SARIFA) predict poor survival in adenocarcinomas of the stomach and gastrooesophageal junction: a validation study.

Recently, the presence of "Stroma AReactive Invasion Front Areas" (SARIFA) has been described as a promising adverse prognostic factor in gastric cancer. However, the validity of this approach still needs to be tested. The aim of this study was to independently assess the utility of the proposed method in a well-characterised cohort of primary resected adenocarcinomas of stomach and gastrooesophageal junction (n = 392). SARIFA status was analysed on routine slides of resection specimens. Cases were divided into SARIFA-positive and negative groups and analysed in relation to clinicopathological and survival data. SARIFA positivity was found in 15.1% (n = 59) cases and was significantly associated with Lauren phenotype (p < 0.001), pT (p = 0.001), pN (p = 0.018), UICC stage (p = 0.031), tumour budding (p = 0.002), overall survival (p < 0.001) and cancer-specific survival (p < 0.001). SARIFA-positive tumours had a worse prognosis in the multivariate setting (HR = 1.847, 95% CI: 1.300-2.624, p = 0.001). SARIFA status is an independent prognostic factor in gastric cancer, in particular in locally advanced tumours.

The MYCN oncoprotein is an RNA-binding accessory factor of the nuclear exosome targeting complex.

The MYCN oncoprotein binds active promoters in a heterodimer with its partner protein MAX. MYCN also interacts with the nuclear exosome, a 3'-5' exoribonuclease complex, suggesting a function in RNA metabolism. Here, we show that MYCN forms stable high-molecular-weight complexes with the exosome and multiple RNA-binding proteins. MYCN binds RNA in vitro and in cells via a conserved sequence termed MYCBoxI. In cells, MYCN associates with thousands of intronic transcripts together with the ZCCHC8 subunit of the nuclear exosome targeting complex and enhances their processing. Perturbing exosome function results in global re-localization of MYCN from promoters to intronic RNAs. On chromatin, MYCN is then replaced by the MNT(MXD6) repressor protein, inhibiting MYCN-dependent transcription. RNA-binding-deficient alleles show that RNA-binding limits MYCN's ability to activate cell growth-related genes but is required for MYCN's ability to promote progression through S phase and enhance the stress resilience of neuroblastoma cells.

Cross-species variability in lobular geometry and cytochrome P450 hepatic zonation: insights into CYP1A2, CYP2D6, CYP2E1 and CYP3A4.

There is a lack of systematic research exploring cross-species variation in liver lobular geometry and zonation patterns of critical drug-metabolizing enzymes, a knowledge gap essential for translational studies. This study investigated the critical interplay between lobular geometry and key cytochrome P450 (CYP) zonation in four species: mouse, rat, pig, and human. We developed an automated pipeline based on whole slide images (WSI) of hematoxylin-eosin-stained liver sections and immunohistochemistry. This pipeline allows accurate quantification of both lobular geometry and zonation patterns of essential CYP proteins. Our analysis of CYP zonal expression shows that all CYP enzymes (besides CYP2D6 with panlobular expression) were observed in the pericentral region in all species, but with distinct differences. Comparison of normalized gradient intensity shows a high similarity between mice and humans, followed by rats. Specifically, CYP1A2 was expressed throughout the pericentral region in mice and humans, whereas it was restricted to a narrow pericentral rim in rats and showed a panlobular pattern in pigs. Similarly, CYP3A4 is present in the pericentral region, but its extent varies considerably in rats and appears panlobular in pigs. CYP2D6 zonal expression consistently shows a panlobular pattern in all species, although the intensity varies. CYP2E1 zonal expression covered the entire pericentral region with extension into the midzone in all four species, suggesting its potential for further cross-species analysis. Analysis of lobular geometry revealed an increase in lobular size with increasing species size, whereas lobular compactness was similar. Based on our results, zonated CYP expression in mice is most similar to humans. Therefore, mice appear to be the most appropriate species for drug metabolism studies unless larger species are required for other purposes, e.g., surgical reasons. CYP selection should be based on species, with CYP2E1 and CYP2D6 being the most preferable to compare four species. CYP1A2 could be considered as an additional CYP for rodent versus human comparisons, and CYP3A4 for mouse/human comparisons. In conclusion, our image analysis pipeline together with suggestions for species and CYP selection can serve to improve future cross-species and translational drug metabolism studies.

Bayesian modelling of time series data (BayModTS)-a FAIR workflow to process sparse and highly variable data.

MOTIVATION: Systems biology aims to better understand living systems through mathematical modelling of experimental and clinical data. A pervasive challenge in quantitative dynamical modelling is the integration of time series measurements, which often have high variability and low sampling resolution. Approaches are required to utilize such information while consistently handling uncertainties. RESULTS: We present BayModTS (Bayesian modelling of time series data), a new FAIR (findable, accessible, interoperable, and reusable) workflow for processing and analysing sparse and highly variable time series data. BayModTS consistently transfers uncertainties from data to model predictions, including process knowledge via parameterized models. Further, credible differences in the dynamics of different conditions can be identified by filtering noise. To demonstrate the power and versatility of BayModTS, we applied it to three hepatic datasets gathered from three different species and with different measurement techniques: (i) blood perfusion measurements by magnetic resonance imaging in rat livers after portal vein ligation, (ii) pharmacokinetic time series of different drugs in normal and steatotic mice, and (iii) CT-based volumetric assessment of human liver remnants after clinical liver resection. AVAILABILITY AND IMPLEMENTATION: The BayModTS codebase is available on GitHub at https://github.com/Systems-Theory-in-Systems-Biology/BayModTS. The repository contains a Python script for the executable BayModTS workflow and a widely applicable SBML (systems biology markup language) model for retarded transient functions. In addition, all examples from the paper are included in the repository. Data and code of the application examples are stored on DaRUS: https://doi.org/10.18419/darus-3876. The raw MRI ROI voxel data were uploaded to DaRUS: https://doi.org/10.18419/darus-3878. The steatosis metabolite data are published on FairdomHub: 10.15490/fairdomhub.1.study.1070.1.

WormBase 2024: status and transitioning to Alliance infrastructure.

WormBase has been the major repository and knowledgebase of information about the genome and genetics of Caenorhabditis elegans and other nematodes of experimental interest for over 2 decades. We have 3 goals: to keep current with the fast-paced C. elegans research, to provide better integration with other resources, and to be sustainable. Here, we discuss the current state of WormBase as well as progress and plans for moving core WormBase infrastructure to the Alliance of Genome Resources (the Alliance). As an Alliance member, WormBase will continue to interact with the C. elegans community, develop new features as needed, and curate key information from the literature and large-scale projects.

Sarcopenic Obesity Promotes Recurrence in Patients Undergoing Resection for Colorectal Liver Metastases (CRLM).

BACKGROUND/AIM: Sarcopenia, is predictive of a worse outcome after resection for colorectal liver metastases (CRLM). Obesity leads to a metabolic double burden if sarcopenia is as present, prompting malignancy progression, known as sarcopenic obesity (SO). This study aimed to compare sarcopenia and SO in patients undergoing CRLM resection, to prognostic parameters. PATIENTS AND METHODS: The skeletal muscle index (SMI) defined sarcopenia using sex specific cut off values (48.4 cm2/m2 for females and 59.1 cm2/m2 for males) by calculating the preoperative muscle mass at the vertebral height L3 using OSIRIX DICOM viewer. SO was determined as sarcopenia in patients showing obesity, as shown via fat percentage measurements on the preoperative CT scan. Established prognostic parameters (KRAS status, TNM classification, inflammatory response) were evaluated against SMI and SO to assess their predictability for postoperative outcomes. RESULTS: A total of 251 patients (62% female, median age 68 years) were included. Sarcopenic patients showed a threefold higher risk for postoperative death as compared to non-sarcopenic patients (p=0.04). Prevalent SO increased this risk to fivefold (p=0.01) compared to non-sarcopenic patients. COX regression analysis revealed SO and KRAS positivity as independent prognostic factors for disease-free survival (SO: p=0.038; KRAS: p=0.041; TNM, tumor size, Charlson Comorbidity Index, platelet-to-lymphocyte ratio, neutrophil-to-lymphocyte ratio all not significant). Patients risk of death in case of KRAS positivity and SO was seven times higher (p=0.03). CONCLUSION: There seems to be a benefit in merging data on mutational status and muscle wasting in patients with CRLM to facilitate an individual, patient-tailored approach.

Portal venous contrast enhancement ratio of the adrenal glands and spleen as prognostic marker of mortality in patients with acute mesenteric ischemia.

PURPOSE: Contrast enhancement of the adrenal gland defined by computed tomography (CT) was previously analyzed as a prognostic factor for critically ill patients in various diseases. However, no study investigated this quantitative parameter in patients with acute mesenteric ischemia. Therefore, the aim of this study was to evaluate the prognostic value of the contrast enhancement of the adrenal glands in patients with clinically suspected AMI. METHODS: All patients with clinically suspected AMI were retrospectively assessed between 2016 and 2020. All patients underwent surgical exploration after CT imaging. Overall, 134 patients (52 female patients, 38.8%) with a mean age of 69.2 ± 12.4 years were included into the present analysis. For all patients, the preoperative CT was used to calculate the contrast media enhancement of the adrenal glands and the spleen. RESULTS: A total of 27 patients (18.5%) died within the first 24 h and over the following 30-day 94 patients (68.6%) died. There were statistically significant differences regarding the mean values for adrenal-to-spleen ratio for 24-h mortality (p = 0.001) and 30-day mortality (p = 0.004), whereas the radiodensity of the inferior vena cava and the radiodensity of the spleen was statistically significant between survivors and non-survivors after 30 days (p = 0.037 and p = 0.028, respectively). In Cox regression analysis, mean adrenal radiodensity was associated with 24-h mortality (HR 1.09, 95% CI 1.02-1.16, p = 0.01) but not with 30-day mortality (HR 1.03, 95% CI 0.99-1.07, p = 0.13). CONCLUSION: The contrast media enhancement of the adrenal gland is associated with the 24-h and 30-day mortality in patients with AMI. However, the prognostic relevance for translation into clinical routine needs to be validated in other cohorts.

Approaching Thrombospondin-1 as a Potential Target for Mesenchymal Stromal Cells to Support Liver Regeneration after Partial Hepatectomy in Mouse and Humans.

Extended liver resection carries the risk of post-surgery liver failure involving thrombospondin-1-mediated aggravation of hepatic epithelial plasticity and function. Mesenchymal stromal cells (MSCs), by interfering with thrombospondin-1 (THBS1), counteract hepatic dysfunction, though the mechanisms involved remain unknown. Herein, two-thirds partial hepatectomy in mice increased hepatic THBS1, downstream transforming growth factor-ß3, and perturbation of liver tissue homeostasis. All these events were ameliorated by hepatic transfusion of human bone marrow-derived MSCs. Treatment attenuated platelet and macrophage recruitment to the liver, both major sources of THBS1. By mitigating THBS1, MSCs muted surgery-induced tissue deterioration and dysfunction, and thus supported post-hepatectomy regeneration. After liver surgery, patients displayed increased tissue THBS1, which is associated with functional impairment and may indicate a higher risk of post-surgery complications. Since liver dysfunction involving THBS1 improves with MSC treatment in various animal models, it seems feasible to also modulate THBS1 in humans to impede post-surgery acute liver failure.

Management of oxidative stress for cell therapy through combinational approaches of stem cells, antioxidants, and photobiomodulation.

Over the recent decades, stem cell-based therapies have been considered as a beneficial approach for the treatment of various diseases. In these types of therapies, the stem cells and their products are used as treating agents. Despite the helpful efficacy of stem cell-based therapies, there may be challenges. Oxidative stress (OS) is one of these challenges that can affect the therapeutic properties of stem cells. Therefore, it seems that employing strategies for the reduction of OS in combination with stem cell therapy can lead to better results of these therapies. Based on the available evidence, antioxidant therapy and photobiomodulation (PBM) are strategies that can regulate the OS in the cells. Antioxidant therapy is a method in which various antioxidants are used in the therapeutic processes. PBM is also the clinical application of light that gained importance in medicine. Antioxidants and PBM can regulate OS by the effect on mitochondria as an important source of OS in the cells. Considering the importance of OS in pathologic pathways and its effect on the treatment outcomes of stem cells, in the present review first the stem cell therapy and effects of OS on this type of therapy are summarized. Then, antioxidant therapy and PBM as approaches for reducing OS with a focus on mitochondrial function are discussed. Also, a novel combination treatment with the hope of achieving better and more stable outcomes in the treatment process of diseases is proposed.

A cobalt concentration sensitive Btu-like system facilitates cobalamin uptake in Anabaena sp. PCC 7120.

Metal homeostasis is central to all forms of life, as metals are essential micronutrients with toxic effects at elevated levels. Macromolecular machines facilitate metal uptake into the cells and their intracellular level is regulated by multiple means, which can involve RNA elements and proteinaceous components. While the general principles and components for uptake and cellular content regulation of, e.g., cobalt have been identified for proteobacteria, the corresponding mechanism in other Gram-negative bacteria such as cyanobacteria remain to be established. Based on their photosynthetic activity, cyanobacteria are known to exhibit a special metal demand in comparison to other bacteria. Here, the regulation by cobalt and cobalamin as well as their uptake is described for Anabaena sp. PCC 7120, a model filamentous heterocyst-forming cyanobacterium. Anabaena contains at least three cobalamin riboswitches in its genome, for one of which the functionality is confirmed here. Moreover, two outer membrane-localized cobalamin TonB-dependent transporters, namely BtuB1 and BtuB2, were identified. BtuB2 is important for fast uptake of cobalamin under conditions with low external cobalt, whereas BtuB1 appears to function in cobalamin uptake under conditions of sufficient cobalt supply. While the general function is comparable, the specific function of the two genes differs and mutants thereof show distinct phenotypes. The uptake of cobalamin depends further on the TonB and a BtuFCD machinery, as mutants of tonB3 and btuD show reduced cobalamin uptake rates. Thus, our results provide novel information on the uptake of cobalamin and the regulation of the cellular cobalt content in cyanobacteria.

Quantifying fat zonation in liver lobules: an integrated multiscale in silico model combining disturbed microperfusion and fat metabolism via a continuum biomechanical bi-scale, tri-phasic approach.

Metabolic zonation refers to the spatial separation of metabolic functions along the sinusoidal axes of the liver. This phenomenon forms the foundation for adjusting hepatic metabolism to physiological requirements in health and disease (e.g., metabolic dysfunction-associated steatotic liver disease/MASLD). Zonated metabolic functions are influenced by zonal morphological abnormalities in the liver, such as periportal fibrosis and pericentral steatosis. We aim to analyze the interplay between microperfusion, oxygen gradient, fat metabolism and resulting zonated fat accumulation in a liver lobule. Therefore we developed a continuum biomechanical, tri-phasic, bi-scale, and multicomponent in silico model, which allows to numerically simulate coupled perfusion-function-growth interactions two-dimensionally in liver lobules. The developed homogenized model has the following specifications: (i) thermodynamically consistent, (ii) tri-phase model (tissue, fat, blood), (iii) penta-substances (glycogen, glucose, lactate, FFA, and oxygen), and (iv) bi-scale approach (lobule, cell). Our presented in silico model accounts for the mutual coupling between spatial and time-dependent liver perfusion, metabolic pathways and fat accumulation. The model thus allows the prediction of fat development in the liver lobule, depending on perfusion, oxygen and plasma concentration of free fatty acids (FFA), oxidative processes, the synthesis and the secretion of triglycerides (TGs). The use of a bi-scale approach allows in addition to focus on scale bridging processes. Thus, we will investigate how changes at the cellular scale affect perfusion at the lobular scale and vice versa. This allows to predict the zonation of fat distribution (periportal or pericentral) depending on initial conditions, as well as external and internal boundary value conditions.