High and pointed type of femoral localized reaction frequently extends to complete and incomplete atypical femoral fracture in patients with autoimmune diseases on long-term glucocorticoids and bisphosphonates.

Once a localized reaction (beaking) was detected, discontinuation of bisphosphonates (BPs) and switching to vitamin D supplementation or teriparatide therapy effectively improved its shape. When the localized reaction was high, of the pointed type, and/or accompanied by prodromal pain, the risks of complete and incomplete atypical femoral fracture increased and consideration of prophylactic fixation for such patients was required. INTRODUCTION: Femoral localized reaction (localized periosteal thickening of the lateral cortex, beaking) is reported to precede atypical femoral fractures (AFFs) and to develop in 8-10% of patients with autoimmune diseases taking BPs and glucocorticoids. The aims of the present study were to retrospectively investigate the shapes of localized reaction to consider how to manage the condition. METHODS: Twenty femora of 12 patients with autoimmune diseases who were on BPs and glucocorticoids exhibited femoral localized reaction. The heights of localized reaction were measured and the shapes classified as pointed, arched, and other. Localized reaction changes were divided into three categories: deterioration, no change, and improvement. A severe form of localized reaction was defined; this was associated with prodromal pain, de novo complete AFF, or incomplete AFF with a fracture line at the localized reaction. RESULTS: The mean height of localized reaction was 2.3 ± 0.8 mm (range, 1.0-3.7 mm) and the pointed type was 35%. Localized reaction was significantly higher (3.3 ± 0.8 vs. 2.1 ± 0.7 mm; p = 0.003) and the pointed type more common (78 vs. 27%; p = 0.035) in those with the severe form of localized reaction. Seven patients with localized reactions discontinued BPs just after localized reaction was detected, but five continued on BPs for 2 years. Localized reaction deterioration was more common in patients who continued than discontinued BPs (100 vs. 29%; p = 0.027). After 2 years, all patients had discontinued BPs and localized reaction did not deteriorate further in any patient. CONCLUSIONS: Once a localized reaction was detected, discontinuation of BPs and switching to vitamin D supplementation or teriparatide therapy effectively improved it. When the localized reaction was high, of the pointed type, and/or accompanied by prodromal pain, the risks of complete and incomplete AFF increased and consideration of prophylactic fixation for such patients was required.

Clinical outcomes of early active mobilization following flexor tendon repair using the six-strand technique: short- and long-term evaluations.

We evaluated the factors influencing outcomes of flexor tendon repair in 112 fingers using a six-strand suture with the Yoshizu #1 technique and early postoperative active mobilization in 101 consecutive patients. A total of 32 fingers had injuries in Zone I, 78 in Zone II, and two in Zone III. The mean follow-up period was 6 months; 16 patients (19 fingers) participated in long-term follow-up of 2 to 16 years. The total active motion was 230° SD 29°; it correlated negatively with age. The total active motion was 231° SD 28° after repair of the lacerated flexor digitorum superficialis tendon, and was 205° SD 37° after excision of the flexor digitorum superficialis tendon ends (p = 0.0093). A total of 19 fingers showed no significant increases in total active motion more than 2 years after surgery. The rupture rate was 5.4% in our patients and related to surgeons' level of expertise. Five out of six ruptured tendons were repaired by inexperienced surgeons. Level of Evidence IV.

Parathyroid hormone increases the expression level of matrix metalloproteinase-13 in vivo.

Parathyroid hormone (PTH) increases serum calcium (Ca) by enhancing bone resorption and renal Ca reabsorption. However, detailed mechanisms of enhanced bone resorption by PTH remain to be elucidated. Although PTH has been shown to increase the expression level of osteoblastic matrix metalloproteinase (MMP)-13 in vitro, only limited results are available regarding the in vivo regulation of MMP expression. In the present study, we have examined expression levels of MMPs in PTH-infused rats. Infusion of 1.5 or 2.0 nmol/kg/day rat PTH(1-34) for 3 days resulted in a dose-dependent increase in serum Ca. PTH infusion also decreased serum phosphate levels and increased urinary excretion of Ca and phosphate. Infusion of PTH for 7 days resulted in less severe hypercalcemia and hypophosphatemia. Urinary Ca and phosphate excretion in rats infused for 7 days was less than that in rats infused for 3 days. Northern blot analysis showed that PTH infusion increased the expression level of MMP-13 in calvaria, although it did not affect MMP-2 expression. Furthermore, the time-course and severity of hypercalcemia and hypercalciuria correlated with the expression level of MMP-13. In situ hybridization also showed that PTH infusion increased the expression level of MMP-13 in femora. These results indicate that PTH enhances MMP-13 expression in vivo and suggest that PTH stimulates bone resorption at least partly by enhancing MMP-13 expression.

Treatment with active vitamin D metabolites and concurrent treatments in the prevention of hip fractures: a retrospective study.

UNLABELLED: The purpose of this study was to determine the effect of treatment with active vitamin D metabolites and other concurrent medication on the prevention of hip fractures in elderly women. We inspected the medical records of the entire female population over 65 years of age on Sado Island, and followed a total of 11,377 women for a 3-year period. Of these, 1208 osteoporotic patients were treated with either 1,25-(OH)2D3 or 1 alpha-(OH)D3. The 765 patients who received the minimum effective dosage for more than 6 months made up the 'treatment group'. Nearly half these patients were also treated with either calcitonin or calcium. The 443 patients who received treatment with active vitamin D metabolites, but at a dosage or for a duration that did not meet the criteria for the treatment group, were deemed the 'ineffective group'. The remaining 10,169 women were the 'non-treatment group'. Fractures in the non-treatment group occurred at a rate of 39.8 fractures/10,000 person-years. The rate in the treatment group was 10.8, which was significantly lower (p = 0.039). Interestingly, the fracture rate after ceasing treatment was 52.1, which was significantly higher (p = 0.002) than the rate in patients receiving treatment. No statistical differences in the fracture rate were found between the ineffective, non-treatment and post-treatment groups. A reduction in the fracture rate was observed only in the treatment subgroup that did not also receive calcitonin (p = 0.042), and not in the subgroup that also received calcitonin therapy (p = 0.333). However, there was no statistical difference in the hip fracture rates between these two subgroups (p = 0.157) and the actual number of fractures was minimal (0 vs 2). Therefore, in this study, the advantage of treatment with active vitamin D alone over combined treatment with calcitonin seems to be marginal. IN CONCLUSION: (1) treatment with active vitamin D metabolites and with combined therapy may be marginally effective in preventing hip fractures, and (2) stopping the treatment clearly increases the risk of hip fractures.

Local effects of transforming growth factor-beta1 on rat calvaria: changes depending on the dose and the injection site.

Transforming growth factor-beta1 (TGF-beta1) has opposite effects on osteoblastic cells in vitro, namely an inhibitory or stimulatory effect on cell differentiation. Because these effects are dependent on TGF-beta1 concentration or culture condition, we investigated whether the in vivo effects of TGF-beta1 on bone formation in infant rat calvaria were affected by the dose or the injection site. Human platelet-derived TGF-beta1 was injected subcutaneously onto the periosteal surface of parietal bone of 4-week-old rats at doses of 5 or 20ng/100microl per animal for 14 days, and the local effect on bone formation was examined by bone histomorphometry. TGF-beta1 treatment for 7 days decreased the mineral apposition rate, bone formation rate, and elongated mineralization lag time at the injection site. This change became more prominent when treatment continued for 14 days. These changes were restricted to the TGF-beta1-exposed area. Multiple subcutaneous injections of a relatively high dose (200ng/100microl per animal) of TGF-beta1 induced woven bone formation, in addition to marked inhibition of bone formation rate and prolongation of mineralization lag time. On the other hand, direct exposure of TGF-beta1 in the subperiosteal layer induced woven bone with periosteal cell proliferation even at a single injection of a low dose (5 or 50ng/25 microl) of TGF-beta1. In conclusion, the in vivo effects of TGF-beta1 on bone formation varied depending on its concentration and injection site. Also, subcutaneous injection of relatively low doses of TGF-beta1 inhibited local lamellar bone formation.

Effects of single and concurrent intermittent administration of human PTH (1-34) and incadronate on cancellous and cortical bone of femoral neck in ovariectomized rats.

The purpose of this study is to determine the efficacy of concurrent treatment with human parathyroid hormone, hPTH (1-34), and bisphosphonate (incadronate) in augmenting cortical and cancellous bone mass of femoral neck in ovariectomized (OVX) rats. Forty-eight 11-week-old female Sprague-Dawley rats were divided into eight groups (six animals in each group). The baseline control group was killed at the beginning of the experiment, at 11 weeks of age. An ovariectomy was performed in thirty rats and twelve rats were subjected to a sham surgery. OVX rats were untreated for the first four weeks of postsurgery to allow for the development of moderate osteopenia. These animals were then subjected to various treatments with either PTH, incadronate, or PTH+ incadronate for a period of 4 weeks. Right proximal femora (femoral necks) were used for bone histomorphometry. After OVX 8 weeks, there was a significant decrease in cancellous bone mass and cortical bone area of femoral neck in the OVX rats when compared to the sham control rats. In OVX rats treated with PTH alone or PTH+ incadronate were completely restored lost cancellous and cortical bone mass of femoral neck by increase bone formation. The bone formation parameters (OS/ BS, MS/BS) and bone turnover (BFR/BV) seen with PTH plus incadronate were similar to those seen with PTH treatment alone. This indicates that incadronate did not blunt the anabolic action of PTH when used concurrently. Our results suggest the followings: 1) the femoral neck of OVX rats is a suitable sample site for preclinical studies of the prevention of bone loss induced by estrogen depletion; 2) concurrent use of incadronate did not blunt the anabolic effect of PTH; 3) concurrent treatment showed the best results in restoring cancellous and cortical bone mass; and 4) it had additional benefits for bone strength independent of that achieved by the increase in bone mass.

Effects of intermittent administration of low dose human PTH(1-34) on cancellous and cortical bone of lumbar vertebral bodies in adult beagles.

This study assessed the effect of low dose human parathyroid hormone [hPTH(1-34)] administration on cancellous and cortical bone of lumbar vertebrae in intact male beagles. 16 19-20-month-old beagle dogs were randomized into four groups: in group 1, the vehicle control group, saline was injected daily; in group 2, the sequential group, 0.375 microg/kg of PTH was injected daily for 4 weeks, then off 8 weeks, and this sequence was once repeated for another 4 and 8 weeks; in group 3, the same dose of PTH was injected once per week for 24 weeks; and, in group 4, PTH was injected three times per week for 24 weeks. Histomorphometric assessment on cancelllous and cortical bone (both ventral and dorsal shell) and two-dimensional node-strut analysis were done on the fifth lumbar vertebral bodies after calcein double bone labeling. In intact adult beagles, on the group treated with 0.375 microg/kg per day three times per week (group 4): (1) had a higher mean value in cancellous bone formation parameters [osteoid surface (+74%), osteoid volume (twofold), mineral apposition rate (+21%), and bone formation rate (twofold)]; (2) exhibited no effect on cortical thickness and porosity in both the ventral and dorsal shell; and (3) showed a lower mean value of node to termini (0.11 +/- 0.02 vs. 0.22 +/- 0.09) and a higher mean value of cortex to node (0.18 +/- 0.06 vs. 0.08 +/- 0.02), but not in trabeculae to trabeculae node, than age-related controls. In conclusion, we found that a low dose of PTH administration: (1) stimulated cancellous bone formation; (2) improved connectivity of trabeculae joined to the cortex; (3) did not decrease cortical thickness; and (4) did not increase cortical porosity in both ventral and dorsal cortexal shell of the lumbar vertebrae during this dosage and period in intact male beagles.

Human protein tyrosine phosphatase-sigma: alternative splicing and inhibition by bisphosphonates.

Two forms of the transmembrane human protein tyrosine phosphatase (PTP sigma), generated by alternative splicing, were identified by cDNA cloning and Northern hybridization with selective cDNA probes. The larger form of PTP sigma is expressed in various human tissues, human osteosarcoma, and rat tibia. The hPTP sigma cDNA codes for a protein of 1911 amino acid residues and is composed of a cytoplasmic region with two PTP domains and an extracellular region that can be organized into three tandem repeats of immunoglobulin-like domains and eight tandem repeats of fibronectin type III-like domains. In the brain, the major transcript of PTP sigma is an alternatively spliced mRNA, in which the coding region for the fibronectin type III-like domains number four to seven are spliced out, thus coding for a protein of 1502 amino acid residues similar to the rat PTP sigma and rat PTP-NE3. Using in situ hybridization, we assigned hPTP sigma to chromosome 6, arm 6q and band 6q15. The bacterial-expressed hPTP sigma exhibits PTPase activity that was inhibited by orthovanadate (IC50 = 0.02 microM) and by two bisphosphonates used for the treatment of bone diseases, alendronate (ALN) (IC50 = 0.5 microM) and etidronate (IC50 = 0.2 microM). In quiescent calvaria osteoblasts, micromolar concentrations of vanadate, ALN and etidronate stimulate cellular proliferation. These findings show tissue-specific alternative splicing of PTP sigma and suggest that PTPs are putative targets of bisphosphonate action.

Lantibiotic nisin Z fermentative production by Lactococcus lactis IO-1: relationship between production of the lantibiotic and lactate and cell growth.

The influence of several parameters on the fermentative production of nisin Z by Lactococcus lactis IO-1 was studied. Considerable attention has been focused on the relationship between the primary metabolite production of bacteriocin and lactate and cell growth, which has so far not been clarified in detail. Production of nisin Z was optimal at 30 degrees C and in the pH range 5.0-5.5. The addition of Ca2+ to the medium showed a stimulating effect on the production of nisin Z. A maximum activity of 3150 IU/ml was obtained during pH-controlled batch fermentation in the medium supplemented with 0.1 M CaCl2. It was about three times higher than that obtained under the optimal conditions for cell growth and lactic acid production.

NER, a new member of the gene family encoding the human steroid hormone nuclear receptor.

NER, a new member of the steroid hormone nuclear receptor (NR)-encoding gene family, was isolated from a human osteosarcoma SAOS/B10 cell line cDNA library. NER codes for a polypeptide of 461 amino acids which contains the conserved sequences of the DNA-binding and ligand-binding domains of typical steroid hormone NR. It has highest homology with the retinoic acid receptors: 55% at the DNA-binding domain and 38-40% at the ligand-binding domain. A single transcript of 2.3 kb was detected in all cells and tissues tested. Although no ligand was identified for NER-I, its wide distribution may indicate that this novel steroid hormone NR may play a basic role in cell function.

cDNA cloning and functional expression of a human monocyte chemoattractant protein 1 receptor.

A novel human G-protein-coupled seven-transmembrane-type receptor gene, 24-1, has been cloned from THP-1 cells. The 24-1 was 56% and 34% identical to the macrophage inflammatory protein-1 alpha (MIP-1 alpha) receptor and the interleukin-8 (IL-8) receptors at the amino acid level, respectively. To examine the ligand specificity of the receptor, we have established a stable transfectant of this gene with human kidney 293 cells. Monocyte chemoattractant protein-1 (MCP-1) induced a rapid increase of Ca++ influx in the 24-1-transfectant, while other C-C chemokines tested did not. This indicates that the 24-1 encodes the human MCP-1 receptor.

Stimulation of complement production in mice by N alpha-(N-acetylmuramyl-L-alanyl-D-isoglutamine)-N epsilon-stearoyl-L-lysine.

N alpha-(N-acetylmuramyl-L-alanyl-D-isoglutamine)-N epsilon-stearoyl-L-lysine, a synthetic muramyl dipeptide analog, stimulated the production of the third component of complement (C3) in mice. The serum concentration of C3 was elevated significantly by subcutaneous treatment with a single dose (10 to 100 micrograms per mouse) of the adjuvant 24 h before assay of the serum. Thereafter, the concentration decreased gradually with time and returned to the normal level on day 4 to 5. Immunoelectrophoretic analysis of the serum revealed that the decrease in serum C3 could not be accounted for by the cleavage to C3a and C3b. By intermittent treatment with the adjuvant on every fifth day, a significant increase in serum C3 was repeated. However, no continuous retention of the serum level of C3 was established even during continuous treatment with the adjuvant once a day for 10 consecutive days. Instead, in this case, the level of C3 increased repeatedly at almost 5-day intervals.