Effect of daily oral minodronate on vertebral fractures in Japanese postmenopausal women with established osteoporosis: a randomized placebo-controlled double-blind study.

UNLABELLED: SUMMARY; A randomized placebo-controlled trial was conducted to examine the effect of daily oral 1 mg minodronate on vertebral fractures in 704 postmenopausal women with established osteoporosis for 24 months. Minodronate treatment reduced vertebral fractures by 59% without serious adverse events. Minodronate is a safe and effective bisphosphonate for osteoporosis treatment. INTRODUCTION: Minodronate increases bone mineral density (BMD) in postmenopausal osteoporotic patients. However, its efficacy in reducing osteoporotic fractures has not been tested. METHODS: To examine anti-fracture efficacy and safety of daily oral minodronate in postmenopausal women with established osteoporosis, a randomized, double-blind, placebo-controlled trial was conducted in 704 postmenopausal women (55 to 80 years) with one to five vertebral fractures and low BMD. Subjects were randomly assigned to receive daily oral 1 mg minodronate (n = 359) or placebo (n = 345) for 24 months, with daily supplements of 600 mg calcium and 200 IU vitamin D(3). RESULTS: Daily 1 mg minodronate for 24 months reduced the risk of vertebral fractures by 59% (95% CI, 36.6-73.3%). Furthermore, when fractures during the first 6 months were eliminated, the risk of vertebral fractures from 6 to 24 months was reduced by 74% in minodronate-treated group. Minodronate treatment also reduced height loss. Bone turnover markers were suppressed by about 50% after 6 months of minodronate treatment and remained suppressed thereafter. The overall safety profile including gastrointestinal safety was similar between the two groups. CONCLUSIONS: Daily oral minodronate is safe, well-tolerated, and is effective in reducing vertebral fracture risk in postmenopausal women with established osteoporosis.

Effect of phosphodiesterase inhibitor-4, rolipram, on new bone formations by recombinant human bone morphogenetic protein-2.

Collagen sponge disks (6 mm diameter, 1 mm thickness) were impregnated with recombinant human bone morphogenetic protein-2 (rhBMP-2) (5 microg/disk) and implanted onto the back muscles of mice. Ten or 20 mg/kg per day of Rolipram, a selective inhibitory agent to phosphodiesterase type 4 (PDE-4), or vehicle, was injected subcutaneously into the host mice for 3 weeks. After treatment, rhBMP-2-induced ectopic ossicles were harvested and examined by radiographic and histologic methods to determine the size, bone quality, and mineral content of the ossicles. The ossicles from a group treated with 20 mg/kg per day Rolipram were significantly larger in size and higher in bone mineral density (BMD) and bone mineral content (BMC) than the control samples. No significant differences were noted in mice treated with 10 mg/kg per day of Rolipram. Histologically, ossicles from the high-dose (20 mg/kg per day) Rolipram-treated group showed densely packed, thicker trabeculae when compared with those from the control group. These experimental results indicate that the PDE-4 inhibitor, Rolipram, may enhance the bone-inducing capacity of BMP-2 in mesenchymal cells. This in turn may result in increased responsiveness to BMP-2 and point to a potential use of PDE-4 inhibitors for the promotion of rhBMP-dependent bone repair.

Polygalacturonase isolated from the culture of the psychrophilic fungus Sclerotinia borealis.

A polygalacturonase was isolated from the culture medium of Sclerotinia borealis, a psychrophilic fungus that grows on lawn and wheat seedling under the snow in winter and induces the snow mold disease. Pectic acid was a better substrate of this enzyme than pectin when the activity was determined by measuring the reducing sugar produced. However, when the activity was measured by viscosity change, the viscosity of pectin decreased more rapidly than that of pectic acid. The results of viscosity change apparently indicate that the polygalacturonase catalyzes pectin hydrolysis as an endo-type enzyme. Highly methyl-esterified pectin was a poor substrate, as determined by measurements of reducing sugar production and viscosity change. It is suggested from the results that the methoxy group of pectin affects the polygalacturonase reaction. A reaction mechanism was proposed for the polygalacturonase reaction. Molecular mass of this enzyme was 40 kDa and its isoelectric point was pH 7.5. Optimum pH of the enzyme reaction was 4.5 and its optimum temperature was 40-50 degrees C. Thirty percent of the maximum activity was observed at 5 degrees C, but it was only slightly active above 60 degrees C. The activity was preserved for more than 2 years at 5 degrees C and pH 4.5, but it was lost when kept at room temperature overnight or heated at 50 degrees C for 30 min. The amino acid sequence of the N-terminal region of the psychrophilic polygalacturonase of Sclerotinia borealis is compared with those of polygalacturonases of mesophilic fungi. The function of this enzyme against the target plants is discussed with reference to the reaction of polygalacturonases of mesophilic fungi.

A cDNA cloning of human AEBP1 from primary cultured osteoblasts and its expression in a differentiating osteoblastic cell line.

By comparing lists of 3'-directed partial cDNA sequences (gene signatures) randomly collected from various tissues, genes uniquely expressed in individual tissue can be identified. A full length cDNA clone, corresponding to one such gene signature, unique to human osteoblast and adipose tissue, was isolated. This cDNA clone encodes a 845-amino acid protein that is almost identical to the mouse adipocyte transcription factor AEBP1 except that it has additional 105 amino acids in the N terminus. A northern hybridization showed that in the differentiating murine osteoblastic cell line, AEBP1 is also expressed but that it is shut off in the final calcification phase, suggesting a transcriptional repressive effect on genes for bone formation.

Bone morphogenetic protein 2 stimulates osteogenesis but does not affect chondrogenesis in osteochondrogenic differentiation of periosteum-derived cells.

The effects of recombinant human bone morphogenetic protein 2 (rhBMP-2) on osteochondrogenesis were examined in high-density cultures of periosteum-derived cells, which have the potential to differentiate into bone and hypertrophic cartilage in vitro. Proliferation of these cells was inhibited by treatment with rhBMP-2. The time course for alkaline phosphatase (ALP) expression was shortened and the mineralization of the culture was increased by supplementation with rhBMP-2. These stimulatory effects of rhBMP-2 were observed at doses of 10-100 ng/m. Bone Gla protein (BGP) was immunocytochemically detectable earlier in the culture treated with rhBMP-2, and the BGP-positive layer of the rhBMP-2-treated cultures was thicker than that of the control cultures. On the other hand, there was no difference in uronic acid content or the time course of alpha 1(II) collagen mRNA expression between the rhBMP-2-treated and the control cultures. These results indicate that rhBMP-2 shortens the time course of osteogenesis and increases the amount of bone formation, whereas chondrogenesis remains unaffected.

Alterations in the expression of osteonectin, osteopontin and osteocalcin mRNAs during the development of skeletal tissues in vivo.

Heterogeneity in the expression of three members of non-collagenous matrix proteins in osteogenic and chondrogenic development in vivo were investigated by in situ hybridization. Sections of several skeletal tissues from mice at various stages of development were hybridized with digoxigenin-labeled complementary RNA probes encoding osteonectin (Osn), osteopontin (Osp) and osteocalcin (Osc). In calvariae and mandibulae, Osn messenger RNA (mRNA) was detected in cells in pre-osseous and osseous tissues before mineralization. Osp mRNA was found in cells attached to the mineralized bone matrix together with Osn mRNA followed by the expression Osc mRNA. In long bones, mRNAs for Osn, Osp and Osc were sequentially expressed with bone development from primary spongiosa to diaphyseal bone. In growth cartilage, Osn mRNA was observed in chondrocytes in non-mineralized cartilage, whereas Osp mRNA was detected in hypertrophic chondrocytes in mineralized cartilage matrix with a characteristic switch in expression. Osc mRNA was not detected in any chondrocytes. These results indicate that osteogenic differentiation in bone development in vivo is characterized by the sequential expression of these three genes, and suggest that these genes are expressed differentially and specifically, in association with extra-cellular matrix mineralization.

Efficacy of alumina ceramic heads for cemented total hip arthroplasty.

Fifty-seven cemented total hip arthroplasties (THAs) were reviewed in cases of osteoarthrosis secondary to congenital dysplasia or dislocation. The bearing surface of the prosthesis used in this series consists of a polyethylene acetabular component on an alumina ceramic head. All acetabular components were positioned at the same level as the original acetabulum, and an autologous femoral head graft was performed for 18 hips. The follow-up period ranged from five to eight years, averaging six years two months. The latest survey showed excellent and good results for 53 hips (92.9%). Four acetabular components (7%) and two femoral components (3.5%) showed roentgenographic evidence of loosening. Only one hip (1.8%) had to be treated with revision surgery for femoral component loosening. None of the cases suffered a broken ceramic head. The use of a total hip prosthesis with an alumina ceramic head in THA is likely to lead to excellent results for patients with osteoarthrosis of the hip.

23(S),25(R)-1,25-dihydroxyvitamin D3-26,23-lactone stimulates murine bone formation in vivo.

23(S),25(R)-1,25-Dihydroxyvitamin D3-26,23-lactone (1,25-lactone) has been shown to have unique actions different from those of 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3]. In contrast to 1,25-(OH)2D3, 1,25-lactone causes a significant reduction in the serum Ca2+ level, stimulates collagen production in an osteoblastic cell line, and inhibits bone resorption induced by 1,25-(OH)2D3. A possible effect of 1,25-lactone on bone formation was examined in experiments on ectopic bone formation using a bone-inducing factor derived from Dunn osteosarcomas. 1,25-Lactone, a metabolite of 1,25-(OH)2D3, increased [3H]proline uptake at the stage of chondrogenesis and 85Sr uptake during bone formation. Significantly enlarged bone was also induced by this compound 3 weeks after implantation. These results suggest that the 1,25-lactone may be able to stimulate bone formation under in vivo conditions.

[Neoplastic angioendotheliosis: a case of T cell lymphoma positive for S-100 protein].

A 63-year-old woman presented with painless, firm, subcutaneous nodules on her legs and trunk. The lesions were annular or serpiginous and their surface was livid-red to pale-red. Superficial lymph nodes were not palpable. Upper gastrointestinal series, barium enema, Ga scintigraphy, and CT findings were negative. Histological examination revealed deep dermal vessels occupied by neoplastic cells and fibrin thrombi. We diagnosed her as having neoplastic angioendotheliosis. Electron microscopically, tumor cells lacked Weibel-Palade bodies. Immunohistochemically, the tumor cells were positive for leukocyte common antigen, T11, MT-1, HLA-DR and S-100 protein. They were negative for Factor VIII-related antigen, epithelial membrane antigen, carcinoembryonic antigen, B-1, and B-2. Immunoelectron microscopic study showed that their nuclei, cytoplasma, and cell membranes were positive for S-100 protein. Based on these findings, we diagnosed her as having T cell lymphoma. The patient rejected chemotherapy and was discharged. Three months after discharge, right hemiplegia developed. Brain CT scan revealed enhanced masses in the left frontal, temporal, and occipital lobes. Craniotomy showed only gliosis and hemorrhage. She died of cerebral bleeding three months after craniotomy.

Effect of phosphorus supplementation on bone formation induced by osteosarcoma-derived bone-inducing substance in X-linked hypophosphatemic mice.

In our previous report, we demonstrated normal cartilage and bone matrix formation and a defect of bone mineralization in hypophosphatemic (Hyp) mice using an ectopic bone formation system. That system consisted of an osteogenic sarcoma-derived bone-inducing substance. In this report, we describe the effect of phosphorus supplementation on abnormal bone mineralization. The osteogenic sarcoma-derived bone-inducing substance was implanted in Hyp mice or control mice. The Hyp mice were divided into two groups after implantation. One group was fed a normal laboratory chow, while the other was fed a high-phosphorus diet for 4 weeks of the experimental period. Normal control mice were fed the normal laboratory chow. The mean serum phosphorus level in the high-phosphorus diet group was normal at 2, 3 and 4 weeks after implantation. Using the method of 85Sr incorporation, the high-phosphorus diet group showed marked improvement in bone mineralization at 2 and 4 weeks after implantation, but incomplete improvement at 3 weeks. On the other hand, histological study of the high-phosphorus diet group at 4 weeks after implantation still showed a meaningful amount of the osteoid matrix formation compared to the control. These findings suggest that the abnormal bone mineralization in Hyp mice was mainly due to their abnormally low serum phosphorus level. However, still other abnormalities might exist and these might be responsible for the incomplete improvement in bone mineralization.

Elongation of brachymetatarsy with ceramic implant: a roentgenographic evaluation of its utility.

The metatarsal bone was elongated by intercalary implantation of a single-crystal alumina ceramic in 7 patients with brachymetatarsy. The implants were encased with new bone 24 months after surgery and resulted in 5.2 to 9.2 mm elongation of the metatarsal bone. The response of the bone to the ceramic implant was observed roentgenographically. No resorption or pseudoarthrosis of the bones, nor loosening or breakage of the implants, were observed. The alumina ceramic implant proved to be a useful substitute for a bone graft, because of its biocompatibility and strength.

Effect of ethane-1-hydroxy-1,1-diphosphonate on ectopic bone formation induced by murine osteosarcoma-derived bone-inducing substance.

The effects of ethane-1-hydroxy-1,1-diphosphonate (EHDP) on ectopic bone formation were studied qualitatively and quantitatively in an experimental system for ectopic bone formation induced by murine osteosarcoma-derived bone-inducing substance. At a low dose of EHDP (3 mg/kg per day i.p.), histologic sequelae of ectopic bone formation were normal, and the size of the induced bone mass was unaffected. At a high dose of EHDP (30 mg/kg per day i.p.), an unmineralized bone matrix with hematopoietic bone marrow was formed without evidence of retardation. This osteoid tissue showed no radiologic and histologic evidence of mineralization during the period of EHDP administration. When EHDP was withdrawn, its inhibitory effect on mineralization was reversed. The induced bone mass was almost the same size as that in controls. These results suggest that EHDP might not prevent ectopic bone matrix formation, but its mineralization and withdrawal of EHDP might lead to the formation of a normal bone similar in size to that formed without EHDP treatment.

[Experimental induction of atherosclerosis in guinea pigs fed a cholesterol and vitamin D2-rich diet].

Atherosclerotic lesions of aorta and arteries were induced in guinea pigs fed a diet supplemented with 1% cholesterol and vitamin D2 (0.75 million IU/kg of diet) for 6 weeks. Histopathological observation revealed intimal proliferation and calcification of the intima and media, but no atheroma was present at the sites of arterial injury. However, the biochemical findings revealed accumulation of cholesterol, mainly esterified, and calcium in the aorta. Significant correlation between the calcium and phosphorus contents in the aorta indicates the presence of a probable calcium-phosphate complex. Synergism for the induction of atherosclerotic lesions was shown between high cholesterol and excess vitamin D2. Sodium 4-(hexadecylamino)benzoate (cetaben) (90 mg/kg/day, p.o.) and trisodium ethane-1-hydroxy-1,1-diphosphonate (EHDP) (5 mg/kg/day, s.c.) inhibited the development of atherosclerotic lesions induced in this manner. These effects were associated with a significant reduction of serum and aortic cholesterol levels and a significant elevation of HDL-cholesterol levels caused by cetaben, and a significant reduction in aortic calcium caused by EHDP. These two drugs and clofibrate, however, had no significant effect on the regression of pre-established atherosclerotic lesions.