Our Research

The James Laboratory is located in the Department of Pathology at Johns Hopkins University School of Medicine. We study mechanisms of bone repair, development, and neoplasia.  A partial description of current research interests is presented below:

Perivascular progenitor cells

psc-mpi-picture

Perivascular stem cells induce ectopic bone formation. MicroCT reconstructions (left) and axial cross-sectional images (right) of ectopic bone after perivascular stem cell implantation.

Once considered a simple regulator of blood flow, it is clear that the vascular wall houses a wealth of resident progenitor or stem cells.  Multipotent mesenchymal progenitors are able to be identified in situ or purified and applied for tissue regeneration purposes.  See below for several links to publications.


Novel differentiation factors for bone repair

skull defect

Colorized micro computed tomography (microCT) reconstruction of a mouse calvarial defect model. On the right, the original and unhealed parietal bone defect site can be visualized in blue. On the left, partial bone defect healing is observed in white.

Numerous growth and differentiation factors are produced or released from bone after injury, some of which aid in the reparative process.  We have shown that exogenous application of positive regulators of Hedgehog and Wnt signaling induce bone healing in both calvarial, axial, and appendicular skeleton. See below for several links to publications.


Bone and soft tissue tumors

SOST H&E

The wide histologic spectrum of osteosarcoma.

Malignant tumors of mesenchymal origin are a complex and heterogeneous group of aggressive tumors, termed sarcomas. Our group is most interested in skeletal sarcomas (osteosarcoma and chondrosarcoma), and perivascular soft tissue tumors.  See below for several links to publications.