Currently, an in vivo model of human breast cancer metastasizing from the orthotopic site to bone does not exist, making it difficult to study the many steps of skeletal metastasis. Moreover, models used to identify the mechanisms by which breast cancer metastasizes to bone are limited to intracardiac injection, which seeds the cancer cells directly into the circulation, thus bypassing the early steps in the metastatic process. Such models do not reflect the full process of metastasis occurring in patients. We have developed an animal model of breast cancer metastasis in which the breast cancer cells and the bone target of osteotropic metastasis are both of human origin. The engrafted human bone is functional, based on finding human IgG in the mouse bloodstream, human B cells in the mouse spleen, and normal bone histology. Furthermore, orthotopic injection of a specific human breast cancer cell line, SUM1315 (derived from a metastatic nodule in a patient), later resulted in both bone and lung metastases. In the case of bone, metastasis was to the human implant and not the mouse skeleton, indicating a species-specific osteotropism. This model replicates the events observed in patients with breast cancer skeletal metastases and serves as a useful and relevant model for studying the disease. (Cancer Res 2005; 65(14): 6130-38)

BACKGROUND:Epidemiologic studies require identification or typing of microbial strains. Macrorestriction DNA mapping analyzed by pulsed-field gel electrophoresis (PFGE) is considered the current gold standard of genomic typing. This technique, however, is difficult to implement because it is labor-intensive and difficult to automate, it requires a long time to obtain results, and results often vary between laboratories.

Small bowel involvement in rheumatoid arthritis is rare and is caused by vasculitis, which results in ulceration, perforation, and necrosis of the small bowel. The authors present a case of rheumatoid vasculitis associated with a small bowel stricture. The patient had a 3-week history of daily postprandial bloating, abdominal cramping, and vomiting. Barium study demonstrated partial small bowel obstruction. Pathologic examination of a resected segment of the small bowel proved that the stricture was caused by rheumatoid vasculitis. To the authors' knowledge, this is the first reported case of such an association in the radiology literature.