131 research outputs found
Bilirubin as an Anti-oxidant for Surgical Stress: A Preliminary Report of Bilirubin Oxidative Metabolites
Background Bilirubin has been recognized as an antioxidant.
The purpose of this study was to examine
whether bilirubin would act as an antioxidant for
surgical stress in humans. Materials and Methods
Serum bilirubin and urinary bilirubin oxidative
metabolites (BOM) were measured in 96 patients
who underwent surgery. The antioxidant activity
of bilirubin was assessed using BOM measured
by enzyme-linked immunosorbent assay with an
anti-bilirubin monoclonal antibody. Results Serum
bilirubin levels increased after surgery in all 96
patients (p<0.01), but did not correlate with operation
time or blood loss (p=0.53 and p=0.28, respectively).
BOM increased only in patients with major
surgeries (p=0.048). Significant correlations between
BOM and operation time and blood loss were found
(p<0.01). Conclusions Bilirubin appears to act as an
antioxidant for invasive surgery in humans. Urinary
BOM could be a reliable marker for the degree of
surgical stress
Phenotype instability of hepatocyte-like cells produced by direct reprogramming of mesenchymal stromal cells
Submitted by Ana Maria Fiscina Sampaio ([email protected]) on 2020-05-20T13:36:52Z
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Orge Yasmin Diniz , Phenotype....pdf: 16650804 bytes, checksum: c3eb41edf819fec369deb1d2cfc161da (MD5)
Orge Yasmin Diniz , Phenotype....pdf: 16650804 bytes, checksum: c3eb41edf819fec369deb1d2cfc161da (MD5)
Previous issue date: 2020Fundação de Amparo à Pesquisa do Estado da Bahia (FAPESB), Conselho
Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação Oswaldo Cruz. Instituto Gonçalo Moniz. Salvador, BA, Brasil / São Rafael Hospital. Center for Biotechnology and Cell Therapy, Salvador, BA, Brazil.MRC Centre for Regenerative Medicine. Edinburgh, UK.Fundação Oswaldo Cruz. Instituto Gonçalo Moniz. Salvador, BA, Brasil / São Rafael Hospital. Center for Biotechnology and Cell Therapy, Salvador, BA, Brazil.Fundação Oswaldo Cruz. Instituto Gonçalo Moniz. Salvador, BA, Brasil / São Rafael Hospital. Center for Biotechnology and Cell Therapy, Salvador, BA, Brazil / D’Or Institute for Research and Education. Rio de Janeiro, RJ, Brazil.Universidade Federal da Bahia. Institute of Health Sciences. Salvador, BA, Brasil.MRC Centre for Regenerative Medicine. Edinburgh, UK.São Rafael Hospital. Center for Biotechnology and Cell Therapy, Salvador, BA, Brazil / D’Or Institute for Research and Education. Rio de Janeiro, RJ, Brazil.São Rafael Hospital. Center for Biotechnology and Cell Therapy, Salvador, BA, Brazil / D’Or Institute for Research and Education. Rio de Janeiro, RJ, Brazil.Fundação Oswaldo Cruz. Instituto Gonçalo Moniz. Salvador, BA, Brasil / National Institute of Science and Technology for Regenerative Medicine. Rio de Janeiro, RJ, Brazil.Fundação Oswaldo Cruz. Instituto Gonçalo Moniz. Salvador, BA, Brasil.Fundação Oswaldo Cruz. Instituto Gonçalo Moniz. Salvador, BA, Brasil / São Rafael Hospital. Center for Biotechnology and Cell Therapy, Salvador, BA, Brazil.MRC Centre for Regenerative Medicine. Edinburgh, UK.Fundação Oswaldo Cruz. Instituto Gonçalo Moniz. Salvador, BA, Brasil / National Institute of Science and Technology for Regenerative Medicine. Rio de Janeiro, RJ, Brazil.Fundação Oswaldo Cruz. Instituto Gonçalo Moniz. Salvador, BA, Brasil / São Rafael Hospital. Center for Biotechnology and Cell Therapy, Salvador, BA, Brazil / D’Or Institute for Research and Education. Rio de Janeiro, RJ, Brazil / National Institute of Science and Technology for Regenerative Medicine. Rio de Janeiro, RJ, Brazil /Hepatocyte-like cells (iHEPs) generated by transcription factor-mediated direct reprogramming of somatic cells have been studied as potential cell sources for the development of novel therapies targeting liver diseases. The mechanisms involved in direct reprogramming, stability after long-term in vitro expansion, and safety profile of reprogrammed cells in different experimental models, however, still require further investigation. Methods: iHEPs were generated by forced expression of Foxa2/Hnf4a in mouse mesenchymal stromal cells and
characterized their phenotype stability by in vitro and in vivo analyses.
Results: The iHEPs expressed mixed hepatocyte and liver progenitor cell markers, were highly proliferative, and
presented metabolic activities in functional assays. A progressive loss of hepatic phenotype, however, was observed
after several passages, leading to an increase in alpha-SMA+ fibroblast-like cells, which could be distinguished and
sorted from iHEPs by differential mitochondrial content. The resulting purified iHEPs proliferated, maintained liver
progenitor cell markers, and, upon stimulation with lineage maturation media, increased expression of either biliary
or hepatocyte markers. In vivo functionality was assessed in independent pre-clinical mouse models. Minimal
engraftment was observed following transplantation in mice with acute acetaminophen-induced liver injury. In
contrast, upon transplantation in a transgenic mouse model presenting host hepatocyte senescence, widespread
engraftment and uncontrolled proliferation of iHEPs was observed, forming islands of epithelial-like cells, adipocytelike
cells, or cells presenting both morphologies.
Conclusion: The results have significant implications for cell reprogramming, suggesting that iHEPs generated by
Foxa2/Hnf4a expression have an unstable phenotype and depend on transgene expression for maintenance of
hepatocyte-like characteristics, showing a tendency to return to the mesenchymal phenotype of origin and a
compromised safety profil
Profiling Circulating and Urinary Bile Acids in Patients with Biliary Obstruction before and after Biliary Stenting
Bile acids are considered as extremely toxic at the high concentrations reached during bile duct obstruction, but each acid displays variable cytotoxic properties. This study investigates how biliary obstruction and restoration of bile flow interferes with urinary and circulating levels of 17 common bile acids. Bile acids (conjugated and unconjugated) were quantified by liquid chromatography coupled with tandem mass spectrometry in serum and urine samples from 17 patients (8 men and 9 women) with biliary obstruction, before and after biliary stenting. Results were compared with serum concentrations measured in 40 age- and sex-paired control donors (20 men and 20 women). The total circulating bile acid concentration increases from 2.7 µM in control donors to 156.9 µM in untreated patients with biliary stenosis. Serum taurocholic and glycocholic acids exhibit 304- and 241-fold accumulations in patients with biliary obstruction compared to controls. The enrichment in chenodeoxycholic acid species reached a maximum of only 39-fold, while all secondary and 6α-hydroxylated species –except taurolithocholic acids – were either unchanged or significantly reduced. Stenting was efficient in restoring an almost normal circulating profile and in reducing urinary bile acids
Background: Tokyo Guidelines for the management of acute cholangitis and cholecystitis
There are no evidence-based-criteria for the diagnosis, severity assessment, of treatment of acute cholecysitis or acute cholangitis. For example, the full complement of symptoms and signs described as Charcot’s triad and as Reynolds’ pentad are infrequent and as such do not really assist the clinician with planning management strategies. In view of these factors, we launched a project to prepare evidence-based guidelines for the management of acute cholangitis and cholecystitis that will be useful in the clinical setting. This research has been funded by the Japanese Ministry of Health, Labour, and Welfare, in cooperation with the Japanese Society for Abdominal Emergency Medicine, the Japan Biliary Association, and the Japanese Society of Hepato-Biliary-Pancreatic Surgery. A working group, consisting of 46 experts in gastroenterology, surgery, internal medicine, emergency medicine, intensive care, and clinical epidemiology, analyzed and examined the literature on patients with cholangitis and cholecystitis in order to produce evidence-based guidelines. During the investigations we found that there was a lack of high-level evidence, for treatments, and the working group formulated the guidelines by obtaining consensus, based on evidence categorized by level, according to the Oxford Centre for Evidence-Based Medicine Levels of Evidence of May 2001 (version 1). This work required more than 20 meetings to obtain a consensus on each item from the working group. Then four forums were held to permit examination of the Guideline details in Japan, both by an external assessment committee and by the working group participants (version 2). As we knew that the diagnosis and management of acute biliary infection may differ from country to country, we appointed a publication committee and held 12 meetings to prepare draft Guidelines in English (version 3). We then had several discussions on these draft guidelines with leading experts in the field throughout the world, via e-mail, leading to version 4. Finally, an International Consensus Meeting took place in Tokyo, on 1–2 April, 2006, to obtain international agreement on diagnostic criteria, severity assessment, and management
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