Systematic optimization of human pluripotent stem cells media using Design of Experiments.

Human pluripotent stem cells (hPSC) are used to study the early stages of human development in vitro and, increasingly due to somatic cell reprogramming, cellular and molecular mechanisms of disease. Cell culture medium is a critical factor for hPSC to maintain pluripotency and self-renewal. Numerous defined culture media have been empirically developed but never systematically optimized for culturing hPSC. We applied design of experiments (DOE), a powerful statistical tool, to improve the medium formulation for hPSC. Using pluripotency and cell growth as read-outs, we determined the optimal concentration of both basic fibroblast growth factor (bFGF) and neuregulin-1 beta 1 (NRG1β1). The resulting formulation, named iDEAL, improved the maintenance and passage of hPSC in both normal and stressful conditions, and affected trimethylated histone 3 lysine 27 (H3K27me3) epigenetic status after genetic reprogramming. It also enhances efficient hPSC plating as single cells. Altogether, iDEAL potentially allows scalable and controllable hPSC culture routine in translational research. Our DOE strategy could also be applied to hPSC differentiation protocols, which often require numerous and complex cell culture media

Unclassified autoimmune pancreatitis mimicking pancreatic cancer

A 24-year-old black male presented with a 1-week obstructive jaundice and intermittent abdominal pain, with no significant weight loss and an unsuspicious abdominal exam. Blood chemistry showed a cholestatic pattern but a complete immunological and tumoral panel (anti-smooth muscle antibody, anti-mitochondrial antibody, anti-nuclear antibody, anti-neutrophil cytoplasmic antibody, anti-Smith, anti-double-stranded-DNA antibody (anti-dsDNA), complement C3/C4, carcinoembryonic antigen, CA 19-9 and IgG4) were all within normal limits. Abdominal ultrasound revealed dilatation of the intra and extra-hepatic bile ducts. CT scan showed an abnormal dilatation of the distal bile duct but no focal enlargement of the head of the pancreas. Endoscopic ultrasound suggested an inflammatory process but the magnetic resonance cholangio-pancreatography favored a neoplastic obstruction of the distal common bile duct. Fine-needle aspiration cytology was insufficient for definitive diagnosis and the patient underwent major surgery. Follow-up with mild exocrine pancreatic insufficiency treated with enzyme replacement.info:eu-repo/semantics/publishedVersio