406 research outputs found
Parenteral iron therapy in obstetrics: 8 years experience with iron-sucrose complex
Fe is an essential component of haem in myoglobin and accounts for 70 % of haemoglobin. The balance of Fe, unlike that of other metals such as Na or Ca, is regulated solely by gastrointestinal absorption, which itself depends on the bioavailability of Fe in food, i.e. the chemical Fe species. Factors that maintain Fe homeostasis by modulating Fe transfer through the intestinal mucosa are found at the luminal, mucosal and systemic levels. Fe deficiency and its consequence, Fe-deficiency anaemia, form the commonest nutritional pathology in pregnant women. The current gold standard to detect Fe deficiency remains the serum ferritin value. Previously there was general consensus against parenteral Fe administration, i.e. parenteral Fe was only recommended for special conditions such as unresponsiveness to oral Fe, intolerance to oral Fe, severe anaemia, lack of time for therapy etc. However, especially in hospital settings, clinicians regularly face these conditions but are still worried about reactions that were described using Fe preparations such as Fe-dextrans. A widely used and safe alternative is the Fe-sucrose complex, which has become of major interest to prevent functional Fe deficiency after use of recombinant erythropoietin Numerous reports show the effectiveness and safety of the Fe-sucrose complex. Good tolerance to this Fe formulation is partly due to the low allergenic effect of the sucrose complex, partly due to slow release of elementary Fe from the complex. Accumulation of Fe-sucrose in parenchyma of organs is low compared with Fe-dextrans or Fe-gluconate, while incorporation into the bone marrow for erythropoiesis is considerably faster. Oral Fe is only started if haemoglobin levels are below 110 g/l. If levels fall below 100 g/l or are below 100 g/l at time of diagnosis, parenteral Fe-sucrose is used primarily. In cases of severe anaemia (haemoglobin <90 g/l) or non-response to parenteral Fe after 2 weeks, recombinant erythropoietin is considered in combination. By using parenteral Fe-sucrose in cases of severe Fe deficiency, anaemia during pregnancy is treated efficiently and safely according to our results and rate of blood transfusion could be reduced considerably to below 1 % of patients per yea
Culture and establishment of self-renewing human and mouse adult liver and pancreas 3D organoids and their genetic manipulation.
Adult somatic tissues have proven difficult to expand in vitro, largely because of the complexity of recreating appropriate environmental signals in culture. We have overcome this problem recently and developed culture conditions for adult stem cells that allow the long-term expansion of adult primary tissues from small intestine, stomach, liver and pancreas into self-assembling 3D structures that we have termed 'organoids'. We provide a detailed protocol that describes how to grow adult mouse and human liver and pancreas organoids, from cell isolation and long-term expansion to genetic manipulation in vitro. Liver and pancreas cells grow in a gel-based extracellular matrix (ECM) and a defined medium. The cells can self-organize into organoids that self-renew in vitro while retaining their tissue-of-origin commitment, genetic stability and potential to differentiate into functional cells in vitro (hepatocytes) and in vivo (hepatocytes and endocrine cells). Genetic modification of these organoids opens up avenues for the manipulation of adult stem cells in vitro, which could facilitate the study of human biology and allow gene correction for regenerative medicine purposes. The complete protocol takes 1-4 weeks to generate self-renewing 3D organoids and to perform genetic manipulation experiments. Personnel with basic scientific training can conduct this protocol.LB is supported by an EMBO Postdoctoral fellowship (EMBO ALTF 794-2014). CH is supported by a Cambridge Stem Cell Institute Seed Fund award and the Herchel Smith Fund. BK is supported by a Sir Henry Dale Fellowship from the Wellcome Trust and the Royal Society. MH is a Wellcome Trust Sir Henry Dale Fellow and is jointly funded by the Wellcome Trust and the Royal Society (104151/Z/14/Z).This is the author accepted manuscript. The final version is available from Nature Publishing Group via http://dx.doi.org/10.1038/nprot.2016.097
RNF43/ZNRF3 loss predisposes to hepatocellular-carcinoma by impairing liver regeneration and altering the liver lipid metabolic ground-state
RNF43/ZNRF3 negatively regulate WNT signalling. Both genes are mutated in several types of cancers, however, their contribution to liver disease is unknown. Here we describe that hepatocyte-specific loss of Rnf43/Znrf3 results in steatohepatitis and in increase in unsaturated lipids, in the absence of dietary fat supplementation. Upon injury, Rnf43/Znrf3 deletion results in defective hepatocyte regeneration and liver cancer, caused by an imbalance between differentiation/proliferation. Using hepatocyte-, hepatoblast- and ductal cell-derived organoids we demonstrate that the differentiation defects and lipid alterations are, in part, cell-autonomous. Interestingly, ZNRF3 mutant liver cancer patients present poorer prognosis, altered hepatic lipid metabolism and steatohepatitis/NASH signatures. Our results imply that RNF43/ZNRF3 predispose to liver cancer by controlling the proliferative/differentiation and lipid metabolic state of hepatocytes. Both mechanisms combined facilitate the progression towards malignancy. Our findings might aid on the management of those RNF43/ZNRF3 mutated individuals at risk of developing fatty liver and/or liver cancer
ICAM-1 nanoclusters regulate hepatic epithelial cell polarity by leukocyte adhesion-independent control of apical actomyosin
Epithelial intercellular adhesion molecule (ICAM)-1 is apically polarized, interacts with,
and guides leukocytes across epithelial barriers. Polarized hepatic epithelia organize their apical
membrane domain into bile canaliculi and ducts, which are not accessible to circulating immune cells
but that nevertheless confine most of ICAM-1. Here, by analyzing ICAM-1_KO human hepatic cells,
liver organoids from ICAM-1_KO mice and rescue-of-function experiments, we show that ICAM-1
regulates epithelial apicobasal polarity in a leukocyte adhesion-independent manner. ICAM-1 signals
to an actomyosin network at the base of canalicular microvilli, thereby controlling the dynamics
and size of bile canalicular-like structures. We identified the scaffolding protein EBP50/NHERF1/
SLC9A3R1, which connects membrane proteins with the underlying actin cytoskeleton, in the proximity interactome of ICAM-1. EBP50 and ICAM-1 form nano-scale domains that overlap in microvilli,
from which ICAM-1 regulates EBP50 nano-organization. Indeed, EBP50 expression is required for
ICAM-1-mediated control of BC morphogenesis and actomyosin. Our findings indicate that ICAM-1
regulates the dynamics of epithelial apical membrane domains beyond its role as a heterotypic cellâ
cell adhesion molecule and reveal potential therapeutic strategies for preserving epithelial architecture during inflammatory stress
Test, Reliability and Functional Safety Trends for Automotive System-on-Chip
This paper encompasses three contributions by industry professionals and university researchers. The contributions describe different trends in automotive products, including both manufacturing test and run-time reliability strategies. The subjects considered in this session deal with critical factors, from optimizing the final test before shipment to market to in-field reliability during operative life
Five yearsâ trajectories of functionality and pain in patients after hip or knee replacement and association with long-term patient survival
To describe the 5 yearsâ trajectories in functionality and pain of patients with hip or knee osteoarthritis and arthroplasty and analyze the association of these with long-term patients survival. Patients with OA receiving total hip or knee arthroplasty were recruited and completed two sets of standardized questionnaires for functionality and pain 6, 12, and 60 months postoperatively. Multivariate mixed models were conducted to assess trajectories over time and the resulting improvement per month during the last time period was included in a landmark-model to estimate adjusted hazard ratios for mortality. In total 809 patients with joint replacement were included (mean age 65.0 years, 62.2% female), 407 patients died (median follow-up 18.4 years). Both instruments of functionality and pain showed extensive improvement during the first 6 months. Baseline and change in functionality (both p < 0.001) and pain (p = 0.02) during the first 6 months were associated with mortality. Better values in functionality corresponded with improved survival whereas the association with the pain scores was inverse. In patients with hip and knee OA, an explicit improvement in function is seen within the first 6 months after arthroplasty. In addition, especially the functionality scores at baseline as well as their improvement showed an association with long-term patient survival
Increased dose efficiency of breast CT with grating interferometry
Refraction-based x-ray imaging can overcome the fundamental contrast limit of computed tomography (CT), particularly in soft tissue, but so far has been constrained to high-dose ex vivo applications or required highly coherent x-ray sources, such as synchrotrons. Here we demonstrate that grating interferometry (GI) is more dose efficient than conventional CT in imaging of human breast under close-to-clinical conditions. Our system, based on a conventional source and commercial gratings, outperformed conventional CT for spatial resolutions better than 263 ”m and absorbed dose of 16 mGy. The sensitivity of GI is constrained by grating fabrication, and further progress will lead to significant improvements of clinical CT
Epigenetic remodelling licences adult cholangiocytes for organoid formation and liver regeneration.
Following severe or chronic liver injury, adult ductal cells (cholangiocytes) contribute to regeneration by restoring both hepatocytes and cholangiocytes. We recently showed that ductal cells clonally expand as self-renewing liver organoids that retain their differentiation capacity into both hepatocytes and ductal cells. However, the molecular mechanisms by which adult ductal-committed cells acquire cellular plasticity, initiate organoids and regenerate the damaged tissue remain largely unknown. Here, we describe that ductal cells undergo a transient, genome-wide, remodelling of their transcriptome and epigenome during organoid initiation and in vivo following tissue damage. TET1-mediated hydroxymethylation licences differentiated ductal cells to initiate organoids and activate the regenerative programme through the transcriptional regulation of stem-cell genes and regenerative pathways including the YAP-Hippo signalling. Our results argue in favour of the remodelling of genomic methylome/hydroxymethylome landscapes as a general mechanism by which differentiated cells exit a committed state in response to tissue damage.RCUK
Cancer Research UK
ERC
H2020
Wellcome Trus
Long-Term Adult Feline Liver Organoid Cultures for Disease Modeling of Hepatic Steatosis.
Hepatic steatosis is a highly prevalent liver disease, yet research is hampered by the lack of tractable cellular and animal models. Steatosis also occurs in cats, where it can cause severe hepatic failure. Previous studies demonstrate the potential of liver organoids for modeling genetic diseases. To examine the possibility of using organoids to model steatosis, we established a long-term feline liver organoid culture with adult liver stem cell characteristics and differentiation potential toward hepatocyte-like cells. Next, organoids from mouse, human, dog, and cat liver were provided with fatty acids. Lipid accumulation was observed in all organoids and interestingly, feline liver organoids accumulated more lipid droplets than human organoids. Finally, we demonstrate effects of interference with ÎČ-oxidation on lipid accumulation in feline liver organoids. In conclusion, feline liver organoids can be successfully cultured and display a predisposition for lipid accumulation, making them an interesting model in hepatic steatosis research
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