Influence of serum percentage on the behavior of Wharton's jelly mesenchymal stem cells in culture.

BACKGROUND: Mesenchymal stem cells (MSCs) are multipotent cells able to differentiate into several lineages with valuable applications in regenerative medicine. MSCs differentiation is highly dependent on physicochemical properties of the culture substrate, cell density and on culture medium composition. OBJECTIVE: In this study, we assessed the influence of fetal bovine serum (FBS) level on Wharton's jelly (WJ)-MSCs behavior seeded on polyelectrolyte multilayer films (PEMF) made of four bilayers of poly-allylamine hydrochloride (PAH) as polycation and poly-styrene sulfonate (PSS) as polyanion. METHODS: MSCs isolated from WJ by explants method were amplified until the third passage. Their phenotypic characterization was performed by flow cytometry analyses. MSCs were seeded on PEMF, in Endothelial growth medium-2 (EGM-2) supplemented by either 5% or 2% FBS. Cell's behavior was monitored for 20 days by optical microscopy and immunofluorescence. RESULTS: Until 2 weeks on glass slides, no difference was observed whatever the FBS percentage. Then with 5% FBS, MSCs formed three-dimensional spheroids on PSS/PAH after 20 days of culture with a nuclear aggregate. Whereas, with 2% FBS, these spheroids did not appear and cells grown in 2D conserved the fibroblast-like morphology. CONCLUSIONS: The decrease of FBS percentage from 5% to 2% avoids 3D cell spheroids formation on PAH/PSS. Such results could guide bioengineering towards building 2D structures like cell layers or 3D structures by increasing the osteogenic or chondrogenic differentiation potential of MSCs.

[Alveolar haemorrhage associated with the primary antiphospholipid syndrome]. / Hémorragie alvéolaire associée à un syndrome primaire des antiphospholipides.

INTRODUCTION: Thrombotic events, particularly pulmonary embolism, are well known presentations of the antiphospholipid syndrome. Other pulmonary manifestations of the disease like alveolar haemorrhage are rare but can represent a catastrophic aspect of this disease. Alveolar haemorrhage in this context is important to recognize since it can be either a complication of anticoagulation therapy or a manifestation of the disease. The therapeutic implications are then very different. CASE PRESENTATION: We present the case of a woman with massive pulmonary embolism treated with thrombolytic therapy. This was complicated by alveolar hemorrhage initially attributed to thrombolytics and recurrent bleeding considered to be a manifestation of the antiphospholipid syndrome. The complicated course necessitated a protracted stay in the intensive care unit, mechanical ventilation, and treatment with intravenous corticosteroids and plasmapheresis. CONCLUSION: Alveolar haemorrhage associated with the antiphospholipid syndrome can be catastrophic and require prompt and aggressive therapy. Plasmapheresis, usually reserved for the catastrophic aspects of this condition, was felt to be useful in this case.