ABSTRACT
Based on their almost unlimited self-renewal capacity and their ability to differentiate into derivatives of all three germ layers, human induced pluripotent stem cells (hiPSCs) might serve as a preferable source for hepatic transplants in metabolic liver disorders or acute liver failure. Furthermore, the generation of patient specific hiPSCs might facilitate the development of innovative therapeutic strategies by accurately modelling disease in vitro. In our study, we aimed for an efficient hepatic differentiation protocol that is applicable for both human embryonic stem cells (hESCs) and hiPSCs. We attempted to accomplish this goal by using a cytokine and small molecule-based protocol for direct differentiation of hESCs and hiPSCs into hepatic cells. Selecting differentiated hepatic cells was possible using an albumin promoter-driven G418 resistance system. Due to IRES-dependent dTomato reporter expression, we were able to track hepatic differentiated cells and we evaluated the most efficient time frame for G418 selection. The status of hepatic differentiation was determined by qRT-PCR comparing the expression of hepatic markers such as AFP, ALB, SOX17, and HNF4 to standard hepatic cells. Functional analysis of the hepatic phenotype was obtained by measuring secreted albumin levels and by analysis of cytochrome P450 type 1A1 activity (EROD). The percentage of differentiated cells was quantified by FACS analysis. In conclusion, our improved protocol demonstrates that both pluripotent cell sources (hESC and hiPSC) can efficiently be differentiated into mature hepatic cells with functional characteristics similar to those of standard hepatic cell lines such as HepG2.
Subject(s)
Cell Differentiation , Hepatocytes/metabolism , Induced Pluripotent Stem Cells/physiology , Animals , Antigens, Differentiation/biosynthesis , Antigens, Differentiation/genetics , Cell Culture Techniques , Cells, Cultured , Cellular Reprogramming , Coculture Techniques , Fibroblasts/physiology , Gene Expression , Homeodomain Proteins/biosynthesis , Homeodomain Proteins/genetics , Humans , Liver/cytology , Mice , Nanog Homeobox Protein , Octamer Transcription Factor-3/biosynthesis , Octamer Transcription Factor-3/genetics , SOXB1 Transcription Factors/biosynthesis , SOXB1 Transcription Factors/geneticsABSTRACT
SUMMARY: Unanticipated difficulties during tracheal intubation and failure to intubate are among the leading causes of anaesthesia-related morbidity and mortality. Using the technique of video laryngoscopy, the alignment of the oral and pharyngeal axes to facilitate tracheal intubation is unnecessary. In this study we evaluated the McGrath Series 5 videolaryngoscope for tracheal intubation in 61 patients who exhibited Cormack and Lehane grade 3 or 4 laryngoscopies with a Macintosh laryngoscope. Using the McGrath resulted in an improved glottic view, compared to Macintosh laryngoscope. Laryngoscopy was improved by one grade in 10%, by two grades in 80% and by three grades in 10% of cases (p < 0.0001). The success rate for intubation was 95% with the McGrath. These results suggest that the McGrath videolaryngoscope can be used with a high success rate to facilitate tracheal intubation in difficult intubation situations.
Subject(s)
Intubation, Intratracheal/instrumentation , Laryngoscopes , Adult , Aged , Aged, 80 and over , Anesthesia, Intravenous/methods , Female , Humans , Intubation, Intratracheal/adverse effects , Intubation, Intratracheal/methods , Laryngoscopes/adverse effects , Laryngoscopy/adverse effects , Laryngoscopy/methods , Male , Middle Aged , Prospective Studies , Trachea/injuries , Treatment Failure , Video Recording/instrumentation , Video Recording/methods , Young AdultABSTRACT
The McGrath video-laryngoscope was used in a patient with immobilized cervical spine and suspected difficult airway after a high level fall with traumatic brain injury and suspected cervical spine trauma. The airway was successfully secured in the preclinical setting using an oral endotracheal tube with full view of the glottis. Because video-laryngoscopy offers potential advantages compared to established airway management techniques, further studies are required to evaluate the significance of video-laryngoscopy in prehospital emergency medicine.
