Adipose tissue derived stromal cells (ATSCs), which were isolated from adipose tissue of rabbit, have shown to possess multipotential, that is, they differentiate into osteoblasts and adipocytes in plate-culturing and into chondrocytes in an established aggregate culture using defined differentiation-inductive medium. The aim of this study was to evaluate the utility of ATSCs in tissue engineering procedures for repair of articular cartilage-defects using the atelocollagen honeycomb-shaped scaffold with a membrane sealing (ACHMS-scaffold). We intended to repair full-thickness articular cartilage defects in rabbit knees using autologously cultured ATSCs embedded in the ACHMS-scaffold. ATSCs were incubated within the ACHMS-scaffold to allow a high density and three-dimensional culture with control medium. An articular cartilage defect was created on the patellar groove of the femur, and the defect was filled with the ATSCs-containing ACHMS-scaffold, ACHMS-scaffold alone, or empty (control). Twelve weeks after the operation, the histological analyses showed that only the defects treated with the ATSCs-containing ACHMS-scaffold were filled with reparative hyaline cartilage, highly expressed Type II collagen. These results indicate that transplantation of autologous ATSCs-containing ACHMS-scaffold is effective in repairing articular cartilage defects.
CD47 is an antiphagocytic molecule that acts via ligation to signal regulatory protein alpha on phagocytes; its enhanced expression and therapeutic targeting have recently been reported for several malignancies. However, CD47 expression in gastric cancer is not well documented. Immunohistochemical expression of CD47 in surgical specimens was investigated. Expression of CD47 and CD44, a known gastric cancer stem cell marker, were investigated in gastric cancer cell lines by flow cytometry. MKN45 and MKN74 gastric cancer cells were sorted by fluorescence-activated cell sorting according to CD44 and CD47 expression levels, and their in vitro proliferation, spheroid-forming capacity, and in vivo tumorigenicity were studied. In vitro phagocytosis of cancer cells by human macrophages in the presence of a CD47 blocking monoclonal antibody (B6H12) and the survival of immunodeficient mice intraperitoneally engrafted with MKN45 cells and B6H12 were compared to experiments using control antibodies. Immunohistochemistry of the clinical specimens indicated that CD47 was positive in 57 out of 115 cases, and its positivity was an independent adverse prognostic factor. Approximately 90% of the MKN45 and MKN74 cells expressed CD47 and CD44. CD47hi gastric cancer cells showed significantly higher proliferation and spheroid colony formation than CD47lo, and CD44hiCD47hi cells showed the highest proliferation in vitro and tumorigenicity in vivo. B6H12 significantly enhanced in vitro phagocytosis of cancer cells by human macrophages and prolonged the survival of intraperitoneal cancer dissemination in mice compared to control antibodies. In conclusion, CD47 is an adverse prognostic factor and promising therapeutic target in gastric cancer.
The relationship between labeling indices of Ki-67 reactive antigen expressed by cycling cells and BrdUrd incorporated into S-phase cells was investigated in 20 patients with malignant tumors. Both of the labeling indices varied greatly from patient to patient; the labeling index of Ki-67 ranged from 37.5% to 1.9% with an average value of 16%, and the BrdUrd labeling index ranged from 23.4% to 1.6% with an average of 9.3%. The Ki-67 labeling index was higher than the BrdUrd labeling index. In general, the values of the Ki-67 labeling index were parallel to those of the BrdUrd labeling index, and the relation Y = 1.59X + 1.15 (r = 0.89) was obtained. In human solid tumors, therefore, the growth fraction can be easily estimated from the S-phase fraction size, and vice versa.
Fine needle aspiration biopsy (FNAB) is a well established method for diagnosing breast lesions, including cancers. FNAB does not require surgery and uses only a small amount of material. FNAB can also be used to acquire material for special studies. This is especially useful with small tumors (≦ 1 cm) when most of the material is needed to make a histologic diagnosis. Immunostaining techniques can be used on FNABs to investigate proliferation by bromodeoxyuridine uptake or Ki‐67 labeling. Immunostaining techniques can also be used to identify oncoprotein expression, such as of p53. Fluorescence in situ hybridization is a technique that can be used to gather cytogenetic information directly from interphase tumor cells and is well suited for use with FNAB material because the harvested nuclei are intact and no cumbersome dissociation processing is needed. Flow cytometric techniques can be applied to FNAB material to study DNA content and S‐phase fraction. Material acquired by FNAB can also be analyzed by the polymerase chain reaction followed by mutation detection. In this report, the authors show the applicability of these various analytic approaches to FNAB material from primary breast cancers. They show that it is essential that the FNAB harvest is representative, ample, and well prepared for the success of these studies.
Macrophage infiltration appears to play an important role in restenosis after arterial intervention. Monocyte chemoattractant protein-1 (MCP-1) is a major chemotactic factor for macrophages. We have previously shown that ramatroban, a thromboxane A(2) (TXA(2)) receptor antagonist, diminished the expression of MCP-1 in human vascular endothelial cells. The aim of this study was to evaluate whether, after balloon angioplasty of atherosclerotic arteries, ramatroban would reduce MCP-1 expression, macrophage accumulation, and neointimal formation. New Zealand white rabbits were fed a cholesterol-rich diet for 4 weeks, and the abdominal aorta of the rabbits were injured by a 2-French Fogarty catheter. They were randomized to receive 1 or 5 mg/kg daily of ramatroban (n = 7 or n = 8) or saline (n = 6). At 4 weeks after balloon angioplasty, the intimal hyperplasia and the macrophage-positive area in the intima by the ramatroban treatment was significantly reduced. Monocyte chemoattractant protein-1 gene expression in injured aortas of the ramatroban-treated group was significantly less evident than in the vehicle-treated group. Thromboxane A(2) receptor blockade by ramatroban for 4 weeks after balloon angioplasty in the atherosclerotic rabbits prevented macrophage infiltration through MCP-1 downregulation and neointimal formation.
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