No abstract

No abstract

We designed an ex vivo bone marrow treatment for breast cancer patients receiving high-dose chemotherapy and autologous bone marrow support (ABMS), using 4-hydroperoxycyclophosphamide (4-HC), an active derivative of cyclophosphamide with known activity against breast cancer. This phase I bone marrow purging trial used ficoll-separated mononuclear cells (MNC) (devoid of granulocytes and RBCs), as opposed to the buffy coat. Twenty-five patients with metastatic breast cancer were studied. Patients received three cycles of the Adriamycin (doxorubicin; Adria Laboratories, Columbus, OH), fluorouracil, and methotrexate (Duke AFM) regimen, followed by marrow harvest. An MNC fraction of marrow was prepared and treated with 4-HC in concentrations of 20 micrograms/mL (four patients), 40 micrograms/mL (four patients), 60 micrograms/mL (nine patients), or 80 micrograms/mL (eight patients) and cryopreserved. Patients then received high-dose systemic cyclophosphamide, cisplatin, and carmustine, followed by infusion of the purged marrow. The study end point was marrow engraftment, defined as WBC count greater than 1,000 cells per microliter. At the first three dose levels (20, 40, and 60 micrograms/mL 4-HC), there was no significant delay in time to engraftment (19, 20, and 23 days, respectively) compared with the unpurged historical controls (17 days). At 80 micrograms/mL, engraftment was significantly delayed compared with the lower concentrations (P = .027), and further escalation of 4-HC was not attempted. A significant correlation was observed between the time of leukocyte engraftment and the 4-HC concentration (P = .017). With a methylcellulose-based tissue culture assay, we demonstrated a statistically significant correlation between the colony-forming unit-granulocyte-macrophage (CFU-GM) content in the purged marrow and the days to engraftment. Ninety-five percent of patients responded clinically to the entire program, 55% of them completely. Longer follow-up is required to assess the ultimate benefit of intensive therapy on long-term survival.

Detection of small numbers of breast cancer cells is important in staging the disease and can be helpful in assessing the efficacy of purging regimens prior to autologous stem cell infusion. Immunohistochemical methods are potentially useful and broadly applicable for this purpose since they are simple to perform, sensitive, and may be quite specific. We have used a combination of four monoclonal antibodies [260F9, 520C9, 317G5 (Baxter Corp); BrE-3 (Dr. R. Ceriani)] against tumor cell surface glycoproteins in a sensitive immunocytochemical assay to identify breast tumor cells in bone marrow and peripheral blood. Immunostained cytospin preparations were fixed prior to staining to preserve cytological details of immunopositive cells. After immunostaining, slides were counterstained with hematoxylin to confirm the identify of labeled cells. In cytocentrifuge experiments in which small numbers of CAMA human breast tumor cells were added to bone marrow mononuclear cells, a linear relationship between the number of tumor cells added and the number of tumor cells detected was obtained over a broad range of tumor cell concentrations. The probability of detecting tumor cells was dependent on the number of cytocentrifuge slides examined. When ten slides (5 million cells) were examined, the probability of detecting tumor at a concentration of 4 tumor cells per million bone marrow mononuclear cells was 98%. In clinical specimens, tumor cells were detected in marrow aspirates from 73 of 240 (30%) patients undergoing autologous transplantation, including 70 (37%) of 190 patients with clinical stage IV disease, 0 of 7 patients with clinical stage III disease, and 3 of 43 (7%) patients with clinical stage II disease. Seventy-three of 657 peripheral blood specimens from 26 of 155 patients (17%) contained breast cancer cells with counts ranging from 1 to 97 tumor cells per million leukocytes. Tumor cells were most frequently found in the blood of patients with stage IV disease [21 of 107 (20%)] but were also found in a substantial number [5 of 44 (11%)] of patients with stage II disease. Positive selection of CD34-positive hematopoietic progenitor cells as well as negative purging methods such as incubation with 4-hydroxyperoxy-cyclophosphamide (4-HC) were evaluated with respect to tumor cell depletion. Selection of CD34-positive progenitor cells from bone marrow or peripheral blood resulted in log reduction of 1 to > 4 tumor cells reinfused at autologous transplantation. A lesser log reduction (up to 1) was demonstrated following 4-HC purging. We conclude that properly performed and controlled immunocytochemical staining of bone marrow and peripheral blood cytospins is a sensitive and simple way to detect and quantitate breast cancer cells in hematopoietic specimens harvested for autotransplantation and that CD34-positive progenitor cell selection results in significant reduction in the number of breast cancer cells reinfused with marrow or peripheral blood stem cells.

There has been some discussion about the relationship between sustainable development and sustainable tourism, and the need to further explore the relationships between theory and practice. Using grounded theory, this paper reviews new and existing research on Beijing's historic hutong neighbourhoods in relation to the housing, heritage conservation and hutong tourism sectors. Results indicate that sustainability as a theoretical category has at least five extant properties. Sustainability is relative, dynamic, normative, contestable and reflexive. Sustainability is relative in the sense that proponents of different sectors will construct it differently. It is dynamic in the related sense that this construction changes over time. Sustainability is normative because it is value-laden; one important ideal being that a sector should strive to become ever more sustainable. Proponents of different sectors will assert their values, hence sustainability is contestable. Finally, sustainability is reflexive in that the normative ideal may not occur, thus the sustainability of a sector will be reflexive of the nature of its evolving real world development. The paper explores the substance of these properties, together with a review of the several stages through which hutong tourism has passed in its short 20-year life, including the emergence of governance systems.