We investigated the influence of acute wounding on tumor growth in a syngeneic mouse breast cancer model. Metastatic mouse breast cancer cells (4T1) were orthotopically injected into the mammary fat pads of BALB/c mice, and animals were wounded locally by full thickness dermal incisions above the mammary fat pads or remotely above the scapula 9 days later. Local, but not remote, wounding increased tumor size when compared with sham treatment. Injection of wound fluid close to the tumor site increased tumor growth, whereas in vitro wound fluid compared with serum increased the proliferation rate of 4T1 cells. Our results show that wound stroma can unfavorably influence growth of nearby tumors. This effect is T cell-dependent, as local wounding had no effect on tumor growth in nu/nu mice. The effect of wounding on tumor growth can be mimicked by acellular wound fluid, suggesting that T cells secrete or mediate secretion of cytokines or growth factors that then accelerate tumor growth. Here, we define an experimental model of wound-promoted tumor growth that will enable us to identify mechanisms and therapeutic targets to reduce the negative effect of tissue repair on residual tumors. [Cancer Res 2008;68(18):7278-82]

We present the concept that a surgical robot may be used to successfully perform a free flap. To study different microsurgical techniques, a porcine free flap model was developed in our laboratory. Dissection of the free flap model and isolation of the vessels were completed under traditional loupe magnification. The da Vinci robot was then used to perform vessel adventitiectomy and microanastomoses. The model was observed for 4 h postoperatively, noting flap color, temperature, capillary refill, and Doppler signal. At the end of this period, the flap was noted to be viable; anastomoses were evaluated and found to be grossly and microscopically patent. Advantages conferred by the da Vinci robot include elimination of tremor, scalable movements, fully articulating instruments with six degrees of spatial freedom, and a dynamic three-dimensional visualization system. Drawbacks include the cost and the absence of true microsurgical instruments.

This report reviews three categories of precursor cells present within adults. The first category of precursor cell, the epiblast-like stem cell, has the potential of forming cells from all three embryonic germ layer lineages, e.g., ectoderm, mesoderm, and endoderm. The second category of precursor cell, the germ layer lineage stem cell, consists of three separate cells. Each of the three cells is committed to form cells limited to a specific embryonic germ layer lineage. Thus the second category consists of germ layer lineage ectodermal stem cells, germ layer lineage mesodermal stem cells, and germ layer lineage endodermal stem cells. The third category of precursor cells, progenitor cells, contains a multitude of cells. These cells are committed to form specific cell and tissue types and are the immediate precursors to the differentiated cells and tissues of the adult. The three categories of precursor cells can be readily isolated from adult tissues. They can be distinguished from each other based on their size, growth in cell culture, expressed genes, cell surface markers, and potential for differentiation. This report also discusses new findings. These findings include the karyotypic analysis of germ layer lineage stem cells; the appearance of dopaminergic neurons after implantation of naive adult pluripotent stem cells into a 6-hydroxydopamine-lesioned Parkinson's model; and the use of adult stem cells as transport mechanisms for exogenous genetic material. We conclude by discussing the potential roles of adult-derived precursor cells as building blocks for tissue repair and as delivery vehicles for molecular medicine.

Many methods for microvascular anastomoses exist, including use of magnifying loupes (x 2.5, x 3.5, x 4.5, x 6), but the operating microscope remains the gold standard. The authors present the da Vinci Surgical System (Intuitive Surgical, Sunnyvale, CA) as an alternative method for performing microvascular anastomoses. The da Vinci robot has fully articulating microinstruments with six degrees of freedom, the ability to filter tremor, the capability to perform telesurgery, and the advantage of 3-D visualization. It offers full and dynamic control over the operating camera, allowing variable positioning and the ability to scale down movements. Its drawbacks include initial high cost, lack of haptic feedback, decreased participation of the first assistant, and lack of widespread availability. In this feasibility study, multiple microanastomoses were performed in canine tarsal and superficial femoral vessels.