Human- and mouse-derived neurons can be simultaneously obtained by co-cultures of human oral mucosal stem cells and mouse neural stem cells.

OBJECTIVE: To observe simultaneous differentiation and analyse possible interactions between co-cultured human oral mucosal stem cells (hOMSC) and mouse neural stem cells (mNSC). MATERIALS AND METHODS: hOMSC and mNSC were co-cultured in mouse and in human medium, and their immunocytochemical characterization to detect survival rate and differentiation pattern was performed. Co-cultures in different media were compared to hOMSC in human medium and mNSC in mouse medium as controls. RESULTS: Co-culture of hOMSC and mNSC in medium for human cells led to normal differentiation pattern of human cells, while mNSC were directed towards astrocytes. When the same cells were cultivated in the mouse medium, both cell types succeeded to form neurons, although mNSC showed a tendency to overgrow hOMSC. hOMSC alone in the human-specific medium differentiated towards ectodermal (Oct4, Map2) and mesodermal (Osterix) cell populations. mNSC in the mouse-specific medium differentiated towards Map2-, ß3-tubulin- and NeuN-positive neurons. CONCLUSIONS: hOMSC and mNSC can form co-cultures. Different media considerably affected the differentiation pattern of co-cultures, whereas one cell population itself modestly influenced differentiation of the other cell type. The in vitro differentiation pattern of hOMSC in the mouse neural tissue environment suggested that hOMSC could be beneficial in the brain tissue affected by ischaemia.

Variations in pectoral girdle muscles in dogs.

Muscle variations take the form of additional muscle bundle or belly, unusual muscle origin or termination, as well as complete muscle absence. Knowledge of such variations not only has clinical importance for guiding surgery, but also can help reveal phylogenetic relationships. To improve our understanding of muscle variations in dogs, 57 medium-sized, cross-breed male and female adult animals were dissected as part of a gross anatomy course between 2005 and 2011. Variations in pectoral girdle muscles were observed in 7 (12.3%) dogs and took the form of an additional muscle bundle in the brachiocephalicus muscle (n = 2), in the omotransversarius muscle (n = 2), in the cervical part of the rhomboideus muscle (n = 2) and in the cervical part of the serratus ventralis muscle (n = 1). Muscle variation was bilateral in only one dog; it involved the omotransversarius muscle. The variations did not seem to be sex dependent. Such variations can appear regularly in dogs and should be taken into consideration during anatomical dissection.