Magnesium enhances adherence and cartilage formation of synovial mesenchymal stem cells through integrins.

OBJECTIVE: We previously reported that more than 60% of synovial mesenchymal stem cells (MSCs) placed on osteochondral defects adhered to the defect within 10 min and promoted cartilage regeneration. The efficiency of adherence is considered to depend on the interaction between cells and extracellular matrix (ECM), in which integrins may play some important roles. Divalent cations such as calcium, magnesium, and manganese may affect functions of integrins, and the integrins may be involved in differentiation of MSCs. Among divalent cations, magnesium is used in clinical practice as a therapeutic agent and increases the affinity of integrin to ECM. In this study, we investigated whether magnesium enhanced adherence and chondrogenesis of synovial MSC through integrins. METHODS: We performed assays for adherence of human synovial MSCs to collagen-coated slides, in vitro chondrogenesis, ex vivo assays for adherence of human synovial MSCs to osteochondral defect, and in vivo assays for adherence and cartilage formation of synovial MSCs in a rabbit osteochondral defect model. RESULTS: Magnesium increased adhesion of human synovial MSCs to collagen, and this effect was inhibited by neutralizing antibodies for integrin α3 and ß1. Magnesium also promoted synthesis of cartilage matrix during in vitro chondrogenesis of synovial MSCs, which was diminished by neutralizing antibodies for integrin ß1 but not for integrin α3. Ex vivo analyses demonstrated that magnesium enhanced adherence of human synovial MSCs to osteochondral defects. In vivo studies in rabbits showed that magnesium promoted adherence at 1 day and cartilage formation of synovial MSCs at 2 weeks. CONCLUSION: Magnesium enhanced adherence of synovial MSCs through integrins, which promoted synthesis of cartilage matrix at an early phase.

[Clinical studies of renal pelvic and ureteral tumors: an analysis of 611 registered cases and progress of treatment].

A review of 611 cases of renal pelvic or ureter tumor registered in Tokai Urological Tumor Registry for the past 10 years from 1980 and comparison of results between the first and latter half was made. The number of renal pelvis tumor was 347 and that of ureter tumors was 264. Clinical stages and pathological grades of the tumor were as follows; Ta, 11.9; T1, 31.8; T2, 14.4; T3, 24.3; T4, 17.6% and G1, 10.5; G2, 49.3; G3, 33.0%. Higher stages and grades were observed in the recent 5 years. Of 409 cases (66.9% in total cases) treated by total nephroureterectomy, 28.3% of the first and 49.0% of the latter half were treated adjunctively by chemotherapy. Five years relative survival rates of these two groups were 49.4 and 47.3%, respectively, suggesting no improved results. A new treatment strategy such as neoadjuvant chemotherapy or lymphadenectomy is expected to improve the prognosis.

A study on elongation and knot slacking of various sutures.

The tension holding capacity of suture materials was measured by in vitro and in vivo experiments. Silk and expanded polytetrafluoroethylene sutures showed large elongation and significant knot slacking after tight tying. Although ultrahigh molecular-weight polyethylene suture had excellent creep resistance, it showed a relatively low tension holding capacity because of substantial knot slacking. On the other hand, polyester and high-strength poly(vinyl alcohol) sutures showed an excellent in vivo tension holding capacity, along with low elongation and insignificant knot slacking. Clinical performance of these sutures was briefly discussed from the mechanical point of view.

[A clinico-pathological study of 69 cases after total cystectomy].

A clinico-pathological study was conducted on 69 patients with bladder cancer who underwent total cystectomy. The one, three and five-year actuarial survival rates for the 69 patients were 73.3%, 48.6% and 44.1%, respectively. Survival rate was not significantly associated with sex, the number of tumors or the size of tumors. The survival rate in those aged 70 years or more was slightly worse than in those who were much younger. Patients with papillary tumors had a more favorable survival rate than those with non-papillary tumors but we could find no significant difference between those with pedunculated tumors and those with sessile tumors. The actuarial 5-year survival rates by grade were 71.9% in G1 + G2, 22.6% in G3 and 32% in non-transitional cell carcinoma; the rates by stage were 86.5% in pTa + pT1, 85.7% in pT2, 20.8% in pT3a, 18.2% in pT3b and 0% in pT4. When the stage reached pT3a, the survival rate fell remarkably. The rate of INF alpha (93.8%) was significantly better than that of INF beta (28.1%) and INF gamma (15.2%). The rate of ly0 (76.2%) was also significantly better than that of ly1 (25.5%) and ly2 (18.8%). There was no significant difference in survival between v(-) (50.7%) and v(+) (25.9%). We could find no significant difference between patients who underwent pelvic lymph nodes dissection and those who did not.(ABSTRACT TRUNCATED AT 250 WORDS)