These findings indicated that a proximal shift in the subsite distribution of colorectal cancer has occurred in Japan. This rightward shift of colorectal cancer is due to the decreasing proportion of rectal cancer. Furthermore, the increasing proportion of older patients, especially females, may be another major determinant of the changing colon cancer subsite distribution.

ObjectiveThis study was undertaken to examine whether bone morphogenetic protein 7 (BMP-7) induces ectopic cartilage formation in the rat tendon, and whether transplantation of tendon treated with BMP-7 promotes meniscal regeneration. Additionally, we analyzed the relative contributions of host and donor cells on the healing process after tendon transplantation in a rat model.MethodsBMP-7 was injected in situ into the Achilles tendon of rats, and the histologic findings and gene profile were evaluated. Achilles tendon injected with 1 μg of BMP-7 was transplanted into a meniscal defect in rats. The regenerated meniscus and articular cartilage were evaluated at 4, 8, and 12 weeks. Achilles tendon from LacZ-transgenic rats was transplanted into the meniscal defect in wild-type rats, and vice versa.ResultsInjection of BMP-7 into the rat Achilles tendon induced the fibrochondrocyte differentiation of tendon cells and changed the collagen gene profile of tendon tissue to more closely approximate meniscal tissue. Transplantation of the rat Achilles tendon into a meniscal defect increased meniscal size. The rats that received the tendon treated with BMP-7 had a meniscus matrix that exhibited increased Safranin O and type II collagen staining, and showed a delay in articular cartilage degradation. Using LacZ-transgenic rats, we determined that the regeneration of the meniscus resulted from contribution from both donor and host cells.ConclusionOur findings indicate that BMP-7 induces ectopic cartilage formation in rat tendons. Transplantation of Achilles tendon treated with BMP-7 promotes meniscus regeneration and prevents cartilage degeneration in a rat model of massive meniscal defect. Native cells in the rat Achilles tendon contribute to meniscal regeneration.

The composition of fatty acids in abdominal subcutaneous adipose tissue and the correlation of fatty acid values of plasma and erythrocytes had not been reported in Japan. The aim of the present study was to investigate the fatty acid composition and correlation of plasma and erythrocyte phospholipids (PL) and adipose triacylglycerols (TG) in 75 adult patients admitted for non-malignant diseases. We also examined the relationship of n-3 and n-6 polyunsaturated fatty acid (PUFA) with patients' characteristics. The total n-3 PUFA were 11.2, 11.8 and 1.9%, and the ratios of n-6/n-3 were 2.41, 1.87 and 8.20 in plasma and erythrocyte PL and adipose TG, respectively. There were the highest correlations for total n-3 PUFA and the n-6/n-3 ratio between plasma and erythrocyte PL and adipose TG. There was a positive correlation between n-3 PUFAs and age, but a negative correlation was found between n-6 PUFAs and age. There was no significant difference in the values of PUFAs in plasma and erythrocyte PL and adipose TG between men and women. The patients with cholesterol cholecystolithiasis showed a significantly lower proportion of eicosapentaenoic acid in plasma and erythrocyte PL than those of the other patients. Our findings suggest that PUFA in plasma and erythrocyte PL may be good biomarkers and more acceptable for studying participants than adipose TG.

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ABSTRACT:We compared the effect of syngeneic and allogeneic transplantation of synovial mesenchymal stem cells (MSCs) for meniscus regeneration in a rat model. Synovium was harvested from the knee joints of three strains of rats. The anterior half of the medial meniscus in both knees of F344 rats was removed and 5 million synovial MSCs derived from F344 (syngeneic transplantation), Lewis (minor mismatched transplantation), and ACI (major mismatched transplantation) were injected into the knee of the F344 rats. At 4 weeks, the area of the regenerated meniscus in the F344 group was significantly larger than that in the ACI group. Histological score was significantly better in the F344 and Lewis groups than in the ACI group at 8 weeks. DiI labeled cells could be observed in the knee joint in the F344 group, but were hardly detected in the ACI group at 1 week. The number of macrophages and CD8 T cells at synovium around the meniscus defect was significantly lower in the F344 group than in the ACI group at 1 week. Syngeneic and minor mismatched transplantation of synovial MSCs promoted meniscus regeneration better than major mismatched transplantation in a rat meniscectmized model. The meniscus is a fibrocartilage whose functions are to increase surface contact area, to absorb mechanical loads, and to improve stability across the knee joint. Meniscal injury is one of the most common injuries of the knee joint, primarily due to sports injuries or degenerative conditions. For injured menisci, efforts have been made to preserve the meniscus as much as possible to prevent degenerative arthritis. For meniscal defects after meniscectomy or meniscal degeneration, transplantations of meniscal grafts or artificial menisci have been attempted; however, the invasiveness, durability and safety of the transplant remain controversial.1 Therefore, a novel strategy for meniscus regeneration is required.Mesenchymal stem cells (MSCs), especially those derived from synovium, are an attractive cell source for meniscus regeneration, because synovial MSCs have remarkable proliferation 2 and chondrogenic potential.3-5 We previously reported that intraarticular injection of synovial MSCs promoted meniscal regeneration in a rat model. 6 It was a syngeneic transplantation model; therefore, possible immune reactions seem to be negligible. MSCs have potent anti-inflammatory/immunosuppressive properties.7 This suggests that allogeneic MSCs can be used therapeutically with equal efficacy to autologous MSCs without triggering the donor specific immune responses. However, this is still controversial, and the opposite results were also reported. [8][9][10] In regard to synovial MSCs, the influence of allogeneic transplantation has not been investigated at all. In this study, we compared the effect of syngeneic and allogeneic transplantation of synovial MSCs for meniscus regeneration in a rat model. For allogeneic transplantations, major antigen mismatched and minor antigen mismatched MSCs were also prepared. MATERIALS AND METHODS AnimalsThis study w...