1,25-Dihydroxyvitamin D3 [1,25-(OH)2D3] increases insulin-like growth factor I (IGF-I) receptors in clonal osteoblastic cells. Study on interaction of IGF-I and 1,25-(OH)2D3

We previously reported a cooperative effect between insulin-like growth factor I (IGF-I) and 1,25-dihydroxy-vitamin D3 [1,25-(OH)2D3] in murine clonal osteoblastic cells, MCT3T3-E1. In the present study, the possible mechanism of interaction between these hormones was investigated. The effect of IGF-I on 1,25-(OH)2D3 receptors in MC3T3-E1 cells was examined. The affinity and hormone binding capacity of 1,25-(OH)2D3 receptors were not altered by IGF-I. Immunoblot analysis showed about 54 kilodaltons (kDa) 1,25-(OH)2D3 receptors, similar to that observed for mouse fibroblasts. The synthesis of IGF-I by the cells under a serum-free condition was determined by RIA. The assay revealed immunoreactive IGF-I secreted by MC3T3-E1 cells (1.79 +/- 0.04 x 10(-9) M, mean +/- SE, n = 5). Rat GH significantly increased the concentration of IGF-I, but 1,25-(OH)2D3 did not. IGF-I radioligand-receptor assay revealed specific binding of IGF-I to MC3T3-E1 cells. The relative potency of IGF-I-related peptides to bind with the cells was in the order of IGF-I much greater than multiplication-stimulating activity (the rat homologue of IGF-II) greater than insulin, and the receptor protein migrated as a 130-kDa band in autoradiography. Scatchard analysis showed a significant increase in IGF-I binding sites by 50% after 3-day treatment with 5 x 10(-11) M 1,25-(OH)2D3, without any change in affinity. These results indicate that the interaction of IGF-I and 1,25-(OH)2D3 in the culture of MC3T3-E1 cells may be mediated by the effect of 1,25-(OH)2D3 on IGF-I receptors.     

N-terminal pro-brain natriuretic peptide predicts hospitalization for ischemic stroke in Japanese hemodialysis patients

Clinical and Experimental Nephrology - The association between N-terminal pro-brain natriuretic peptide (NT-proBNP) and stroke in Japanese hemodialysis (HD) outpatients is unclear. Therefore, in...     

Long-term skeletal stability in the treatment of mandibular prognathism with a physiological positioning strategy

Our aim was to evaluate the long-term skeletal stability of the mandible in 21 patients after orthognathic surgery with physiological positioning. The measurement points SNB, B point (X, Y), Pog (X, Y), and the angle of the ramus were measured on cephalometric photographs to assess skeletal stability preoperatively, immediately after operation, and one and two years postoperatively. In addition, we evaluated the clinical symptoms of disorders of the temporomandibular joint (TMJ). The analysis of the cephalometric photographs showed that SNB, B point X, and Pog X showed no significant differences among the postoperative time points. On the other hand, B point Y and Pog Y showed no significant differences throughout the study period. We compared the angle of the ramus before operation and two years postoperatively, and no significant difference was found. In addition, no cases showed any pathological symptoms of disorders of the TMJ two years postoperatively. The long-term stability after orthognathic surgery with physiological positioning was confirmed, and it seems to be a reliable orthognathic treatment in patients with mandibular prognathism.     

Portal blood flow and liver regeneration in auxiliary partial orthotopic liver transplantation in a canine model

Functional competition has been shown to lead to a detrimental outcome in auxiliary liver transplantation. We evaluated the interaction in auxiliary partial orthotopic liver transplantation between the native liver and the graft in terms of portal flow and regeneration. The need for diversion of the portal flow to the graft was also assessed. Reduced-size liver grafts were transplanted orthotopically after partial hepatectomy in beagles. There were two groups: the preserved group, where portal inflow to the native liver was preserved, and the ligated group, where it was interrupted. Portal flow was measured serially and liver regeneration was evaluated on postoperative day 5. Functional competition was not observed in the preserved group. On the other hand, ligation of the native liver portal vein had no obviously detrimental effects on the remnant native liver. This leads to the conclusion that the portal vein to the native liver can be safely ligated to prevent functional competition.     

Surgical treatment of lung cancer with combined resection of the aorta or superior vena cava

Until December 1997, 699 cases of lung cancer were resected in our institute. Four cases of invasion into the aorta and seven cases of invasion into the superior vena cava were also operated and each vessels were reconstructed. Two pneumonectomies and nine lobectomies were performed. Four cases of squamous cell carcinoma, three of adenocarcinoma, three of large cell carcinoma and one of adenosquamous carcinoma were found on pathological examination. Four cases of N0, four of N2 and two of N3 were also detected on pathological lymph node evaluation. One case was stage IV with metastasis of ipsilateral axillar lymph nodes and the others were stage IIIB. With respect to pathological curability, absolutely noncurative operation was performed in all cases involving the aorta and absolutely noncurative in four and relatively curative three in cases involving the superior vena cava. During resection and reconstruction of the aorta, three cases received temporary blood supplying bypass and one case was underwent temporary clamping. Two cases developed bilateral lower extremity paralysis. During resection and reconstruction of the superior vena cava, one case underwent intraluminal temporary blood supplying bypass, two received sideclamping and four were reconstructed with double artificial grafts for bilateral innominate veins. Two cases who underwent resection of the aorta died within one year and one is alive after nine months of operation. Five cases who underwent resection of the superior vena cava died due to cancer. One case of N0 and relatively curative is alive in free of recurrence after seven years and six months of operation and another case who had brain metastasis resected is alive after two years and two months of pulmonary operation. Careful selection should be made for resection of the aorta because the prognosis is usually poor. In the resection of the superior vena cava, good prognosis is expected in some cases (N0, relatively curative) and quality of life is expected to improve with the prevention of the superior vena cava syndrome. Aggressive resection should be considered for lung cancer invasion into the superior vena cava.     

Involvement of calcium ion in elevation of mRNA for gamma-glutamylcysteine synthetase (gamma-GCS) induced by low-dose gamma-rays

PURPOSE: To investigate the mechanism of the intracellular glutathione elevation induced by low-dose gamma-radiation. MATERIALS AND METHODS: RAW 264.7 cells were irradiated with 1-400cGy gamma-rays. Intracellular total glutathione content was determined by DTNB-recycling assay. Expression of mRNA for intracellular glutathione synthesis-related enzymes with or without treatment with various inhibitors of second messengers of gene expression were examined by Northern blot analysis. RESULTS: Expression of mRNA for gamma-glutamylcysteine synthetase (gamma-GCS), a rate-limiting enzyme of the de novo glutathione synthesis pathway, was elevated much more than that of glutathione reductase (GR) mRNA after exposure to 50cGy gamma-rays. The low-dose gamma-ray-induced gamma-GCS mRNA elevation was abolished by inhibitors of protein kinase C and protein tyrosine kinase, as well as by the calcium ion channel blocker, nifedipine. Calcium-related reagents, such BAPTA/AM and EGTA, chelators of intra- and extracellular Ca2+ respectively, and a Ca2+ ionophore (A23187), also strongly blocked the elevation of gamma-GCS mRNA expression induced by gamma-rays. CONCLUSIONS: The increase of intracellular glutathione in RAW 264.7 soon after low-dose gamma-ray exposure mainly occurs through the operation of the de novo pathway, following by the induction of gamma-GCS mRNA, for which elevation of intracellular calcium is required.     

Effect of porcine calcitonin therapy on vitamin D metabolism and clinical response in a patient with osteogenesis imperfecta

A 1 11/12-year-old girl with osteogenesis imperfecta was treated with porcine calcitonin. Eight bone fractures occurred in the previous 20 months before therapy, but none occurred during eight months of therapy. There was also a significant improvement in linear growth and radiographic bone density. This is the first study of the effect of calcitonin on vitamin D metabolism in a human. The high plasma levels of 1,25 dihydroxy-vitamin D (1,25-(OH)2-D) and 24,25 dihydroxy-vitamin D (24,25-(OH)2-D) before calcitonin therapy decreased after therapy. Plasma 25 hydroxy-vitamin D (25-OH-D) concentration, which normal in level before calcitonin therapy, was normal or slightly decreased during administration. It is concluded that calcitonin probably influences vitamin D metabolism in a patient with osteogenesis imperfecta.     

MR imaging of müllerian mucinous borderline tumors arising from endometriotic cysts

This report describes MR findings of müllerian mucinous borderline tumors, pathologically proven to have arisen from endometriotic cysts, in three patients. They were unilocular or paucilocular masses with mural nodules. Cystic components showed hyperintensity on both T1- and T2-weighted images, simulating clear cell or endometrioid carcinomas arising from endometriotic cysts. Mural nodules showed prominent high signal intensity on T2-weighted images. Correlation with pathologic findings suggests that this hyperintensity reflects intraluminal mucinous material and stromal edema.