Protective effects of intracellular reactive oxygen species generated by 6-formylpterin on tumor necrosis factor-alpha-induced apoptotic cell injury in cultured rat hepatocytes

The effects of 6-formylpterin on tumor necrosis factor (TNF)-alpha-induced apoptotic cell injury were studied in cultured rat hepatocytes. The incubation of the hepatocytes with TNF-alpha and actinomycin D (ActD) induced the apoptotic cell injury. The level of aspartate transaminase (AST) in the culture supernatant increased, and the cell viability, estimated by mitochondrial respiration (MTT assay), decreased. The DNA fragmentation and the caspase 3-like activity, which are characterized to apoptosis, increased. When the hepatocytes were incubated with 100-500 microM 6-formylpterin, the intracellular formation of reactive oxygen species (ROS) was observed, and the ratio of reduced and oxidized glutathione (GSH/GSSG) of whole cell lysate decreased. The co-incubation of the TNF-alpha/ActD-treated hepatocytes with 100-500 microM 6-formylpterin attenuated the TNF-alpha/ActD-induced apoptotic cell injury. The level of AST decreased and the cell viability increased. Both the DNA fragmentation and the caspase 3-like activity decreased. The caspases, executors of apoptosis, are known to require a reduced cystein in their active site to function, and the intact intracellular GSH/GSSG is essential for the caspase activation. Therefore, our findings suggest that intracellular ROS generated by 6-formylpterin decline the intracellular redox state to an oxidant state, which suppresses the caspase activity and prevents the apoptotic cell injury of hepatocytes.

Treatment of pathological fracture of the femur due to diffuse haemangioma in the lower limb

We describe two patients with a diffuse haemangioma of the lower limb complicated by pathological fracture of the femoral shaft, one of whom was treated by a bone graft and immobilisation in a cast, and the other by external fixation and injection of bone marrow. A review of the literature identified difficulty in control of bleeding and obtaining bony union.

Flow-injection EPR investigation on OH radical scavenging activity of Gd(III) containing MRI contrast media

The OH radical scavenging activity of a series of Gd(III) MRI contrast media, such as Gd(III)DTPA, Gd(III)BMA and Gd(III)DO3A, were evaluated by means of EPR spin trapping measurements. The second order reaction rate constant (k2) occurring between Gd(III)DTPA and OH radical was estimated to be 3.26 x 10(10) (M(-1)s(-1)), which was ten times larger than that of the free ligand DTPA (3.86 x 10(9) M(-1)s(-1). The k2 values of Gd(III)BMA and Gd(III)DO3A were also determined to be 1.31 x 10(10) and 1.77 x 10(10) (M(-1)s(1)), respectively. The present results suggest that widely used Gd(III) containing MRI reagent exhibit OH radical scavenging activity, and these values of k2 are same order as that of ascorbic acid (1.16 x 10(10) M(-1)s(-1)) which has been well established to be the most powerful OH radical scavenger. Based on the EPR measurements performed for these Gd(III) complexes, a possible reaction mechanism of the OH radical scavenging action of these MRI contrast media will be discussed.

6-Formylpterin protects retinal neurons from transient ischemia-reperfusion injury in rats: a morphological and immunohistochemical study

Neuroprotective effects of 6-formylpterin (6FP) on transient retinal ischemia-reperfusion injury were evaluated in rats by means of counting the number of retinal ganglion cells, measuring the thicknesses of the inner plexiform and inner nuclear layers, and by immunohistochemical detection of apoptotic cells in the retina. Sixty-one Sprague-Dawley rats (12 weeks, male, 295-330 g) were subjected to transient retinal ischemia-reperfusion by elevated intra-ocular pressure (80 mmHg for 60 min). Intraperitoneal injection of 6FP (3.8 mg/kg) was performed before or after ischemia. The retina was histologically better preserved in rats with 6FP treatment than without 6FP treatment. 6FP showed more strong neuroprotective effects when it was administered before ischemia. The number of single-stranded DNA-positive cells in the retina also decreased remarkably in rats with 6FP treatment, especially when administered before ischemia. These results suggest that 6FP protects retinal neurons from transient ischemia-reperfusion injury, at least in part by inhibiting apoptotic cell death.

Coxsackievirus and adenovirus receptor (CAR)-positive immature osteoblasts as targets of adenovirus-mediated gene transfer for fracture healing

Adenovirus vectors are expected to be a powerful tool for gene therapy to treat severe fractures. Adenovirus invades cells through binding to the coxsackievirus and adenovirus receptor (CAR) on the cell membrane. CAR expression is low in normal adult animals, but it is induced on regenerating cells in some experimental models. We made a rib fracture model in mice and evaluated the histological changes and CAR mRNA expression by RT-PCR 1, 5, 10, 14, and 21 days after the fracture. CAR mRNA was expressed exclusively in the fractured ribs at each time point, but not in the normal ribs. We detected the CAR protein immunohistochemically in fibroblast-like cells in the fracture callus on days 10 and 14 after fracture. In situ hybridization showed that these fibroblast-like cells expressed mRNA of type I collagen and osteopontin, but not osteocalcin, defining the cells as immature osteoblasts. We then transferred small doses (10(4)-10(8) PFU) of lacZ-expressing adenovirus vector into immature osteoblasts on day 14. beta-galactosidase was detected only on the immature osteoblasts at every dose. Immature osteoblasts play an important role in the matrix replacement step in fracture healing. CAR-mediated gene transfer into immature osteoblasts can be reasonable for adenovirus-mediated treatment of fracture healing.

Treatment of myxoid liposarcoma by marginal or intralesional resection combined with radiotherapy

Local recurrence-free survival rate for myxoid liposarcoma (MLS) is related to negative surgical margins. The goal of surgery in the treatment of MLS is to obtain tumor-free surgical margins. When a tumor is adjacent to critical structures, wider resection, which can result in amputation, would be selected for local control. While recognizing that marginal or intralesional resection is associated with high risk of recurrence, circumstances occur that lead surgeons to conduct conservative surgery. To determine whether marginal or intralesional resection combined with radiotherapy can achieve local control, 10 cases (12 tumors) were reviewed involving MLS treated with marginal (8 tumors) or intralesional resection (4 tumors) followed by postoperative radiotherapy (50-70 Gy, average 59.2 Gy). No recurrences of MLS were observed locally at the mean follow-up of 58.1 months. The development of severe radiation-related complications was not detected. This medium follow-up study suggested that this method can achieve a high rate of local control.

Increase in serum 1,25-dihydroxyvitamin D and hypercalcaemia in a patient with inflammatory myofibroblastic tumour

Hypercalcaemia complicates the clinical course of a substantial number of patients with advanced cancer. This report describes a patient with an inflammatory myofibroblastic tumour in soft tissue who developed an inflammatory reaction, hypercalcaemia, and a high serum concentration of 1,25 dihydroxyvitamin D. Serum concentrations of 25-hydroxyvitamin D, parathyroid hormone, and parathyroid hormone related protein were normal. Histological examination of the tumour revealed fibrosarcoma with abundant macrophage infiltration. mRNA for 25-hydroxyvitamin D-1alpha-hydroxylase was identified in the tumoral tissue. In view of this case, inflammatory myofibroblastic tumour should be added to the list of diseases that are responsible for vitamin D mediated hypercalcaemia.

[Thoracic kyphotic deformity impairs QOL of osteoporotic patients]

Severe osteoporotic patients likely to have multiple spinal compression fractures, resulting in spinal kyphotic deformity. We compared the QOL of osteoporotic patients between the patients with and without thoracic kyphosis using the questionnaire of the Japanese Bone and Mineral Society for osteoporotic patients (1999 version). The patients with thoracic kyphosis, whose thoracic kyphotic angles were over than 45 degrees, complained low back pain, disturbance of activity of daily living, anxiety about falling, and dissatisfaction with their posture. We have to concern about the QOL and take care of psychological aspects of osteoporotic patients with spinal deformity as well as low back pain.

A PCR-ELISA assay for the detection of disseminated osteosarcoma cells in a mouse metastatic model

Circulating tumor cells in the blood play a central role in the metastatic process. There have been no reports describing the relationship between lung metastasis and circulating osteosarcoma cells. We developed a system with a polymerase chain reaction assay based on an enzyme-linked immunosorbent assay (PCR-ELISA) to detect circulating osteosarcoma cells in a mouse metastatic model. Osf2/Cbfa1, hereafter called Osf2, a member of the runt family of transcription factors, was used as a target gene. One splicing variant of Osf2 mRNA was identified and its expression was restricted to the bones and osteosarcomas. The amount of the splicing variant of Osf2 mRNA was significantly higher in the blood of mice with metastasis than in the blood of the control group. The PCR-ELISA using Osf2 mRNA is a potential method to detect circulating osteosarcoma cells in peripheral blood.

[Determinants of occurrence of negative priming for novel shapes with matching paradigm]

We examined the effect of relation between interferences from distractor and inhibitory mechanism on the occurrence of negative priming, by using a matching paradigm. The ease of perceptual target selection was determined by magnitudes of interference. Stereoscopic depth was used to manipulate the relative position of a target, a distractor and a standard figure. When the ease of perceptual target selection was manipulated by separation of the target from the distractor in depth, positive priming occurred. However, the ease of target selection turned out to be unnecessary in the occurrence of priming effects. When the distractor and the standard figure were displayed at the same depth plane, where the distractor was supposed to interfere with the encoding of a standard figure, negative priming occurred consistently regardless of the ease of perceptual target selection. This study suggests that inhibitory mechanism contributes to the suppression of inappropriate processes by distractor, and inhibitory mechanism actively keeps distractors from interfering with standard figures.

Relief from pain after Bombelli's valgus-extension osteotomy, and effectiveness of the combined shelf operation

Between 1979 and 1993, we treated 67 hips in 58 patients with severe osteoarthritis caused by congenital dislocation of the hip, employing Bombelli's valgus-extension osteotomy. The mean age of the patients was 43.6 years (range, 23-59 years). The mean follow-up period was 9.7 years (range, 5-16 years). Thirty-three of the 67 joints were followed-up for more than 10 years after the operation. Of the 67 joints, 31 were operated on by Bombelli's valgus-extension osteotomy combined with a shelf operation (combined group), and 36 by Bombelli's valgus-extension osteotomy alone (single group). Clinical evaluation was made according to the Japanese Orthopaedic Association (JOA) hip score system (JOA hip score). In order to assess the effectiveness of this operation in regard to sustained relief from pain after the operation, Kaplan-Meier survivor analysis was performed on the basis of pain score on the JOA hip score. The end-point of the Kaplan-Meier analysis was defined as a score of less than 20 points on the pain score at the time of follow-up or conversion to total hip arthroplasty. In order to analyze the factors that exacerbated pain and to assess the effectiveness of the combined shelf operation, the degree of superior displacement of the femoral head (measured from roentgenograms) after the operation was examined in relation to the pain score. The mean JOA hip score improved, from 56.1+/-11.0 before the operation to 77.0+/-16.1 at the latest follow-up. Kaplan-Meier analysis showed a survival rate of 79.4% 10 years after the operation. Superior displacement of the femoral head had gradually progressed with time after the operation in patients with and without the combined shelf operation. Displacement of the femoral head was positively correlated with the acetabular angle of the weight-bearing surface (WBS angle) (sourcil) preoperation. The mean pain score in the combined group was significantly higher than that in the single group 6 to 9 years after the operation. The results of our assessments led us to conclude that Bombelli's valgus-extention osteotomy is satisfactory as far as clinical and radiological evaluations are concerned, as relief from the pain has continued for more than 10 years after the operation. The combined shelf operation is effective for relieving pain in severe osteoarthritis caused by congenital dislocation of the hip.

6-formylpterin, a xanthine oxidase inhibitor, intracellularly generates reactive oxygen species involved in apoptosis and cell proliferation

The chemical property of 6-formylpterin and its biological functions were examined. Polarographic studies revealed that 6-formylpterin reacted with NAD(P)H and consumed oxygen. In contrast, other conjugated pterins, such as biopterin and neopterin, showed no consumption of oxygen. The production analysis using high-performance liquid chromatography documented that 6-formylpterin catalyzes the conversion from NADH to NAD. Electroparamagnetic resonance spin trapping experiments demonstrated that this reaction is accompanied with the generation of reactive oxygen species (ROS), superoxide anion and hydrogen peroxide. When 6-formylpterin was administered to HL-60 cells, intracellular ROS generation was observed and apoptosis was induced. In contrast, other conjugated pterins induced neither intracellular ROS generation nor apoptosis in HL-60 cells. The intracellular ROS generation by 6-formylpterin was observed in other cells, such as PanC-1 cells and Jurkat cells. 6-formylpterin suppressed cell proliferation in PanC-1 cells and inhibited Fas-mediated apoptosis in Jurkat cells. These findings indicate that, among conjugated pterins, 6-formylpterin has the unique property to transfer electron from NAD(P)H to oxygen and that the property brings about intracellular ROS generation, which exerts various biological functions such as induction of apoptosis, suppression of cell proliferation, and inhibition of Fas-mediated apoptosis.

Recurrent malignant variant of phosphaturic mesenchymal tumor with oncogenic osteomalacia

Phosphaturic mesenchymal tumor is a rare neoplasm which causes osteomalacia or rickets. The tumor typically follows a benign clinical course. Even in the rare malignant cases, local recurrence and distant metastasis are uncommon. We report on an example of a malignant phosphaturic mesenchymal tumor which recurred several times over 16 years concurrently causing hypophosphatemia, bone pain, and osteomalacia. Following each surgery, symptoms and hypophosphatemia improved. The patient died of disease 17 years after the first surgery. Histologically, the initial tumor was composed of small spindle cells with clusters of giant cells, prominent blood vessels, poorly formed cartilaginous areas, and crystalline material. Cytological atypia was minimal. Following multiple recurrences, the tumor demonstrated areas of high-grade sarcoma exhibiting marked pleomorphism, numerous mitotic figures, and p53 overexpression. This case illustrates the potential lethality of incompletely removed phosphaturic mesenchymal tumors.

Immunohistochemistry of atrial natriuretic peptide in brain infarction

Atrial natriuretic peptide (ANP) was originally isolated from cardiac atria, and has potent natriuretic, diuretic, and vasorelaxant properties. It has been localized in neurons and astrocytes in the cerebral cortex and the white matter. We hypothesize that glial ANP may contribute to the regulation of cerebral blood flow in brain infarction. In order to elucidate this possible role, the immunohistochemistry of ANP was studied in cases of brain infarction and in other cases of brain trauma for comparison. A statistically significant increase in the number of ANP-immunoreactive glial cells (mainly astrocytes) was observed in the white matter surrounding the brain infarction compared with the intact area. No statistically significant increase in ANP-immunoreactive glial cell number was observed in the cerebral white matter from brain haemorrhage, contusion and control cases. Our results indicate that glial ANP may increase in number in brain infarction, and that it may be involved in the regulation of the cerebral blood flow in the infarcted area.

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.

Elevation of serum alkaline phosphatase in clear cell chondrosarcoma of bone

BACKGROUND

Clear cell chondrosarcoma is a rare bone tumor, which is sometimes misdiagnosed as a different bone neoplasm.

MATERIALS AND METHODS

The files of 6 patients with clear cell chondrosarcomas were reviewed. Histological slides, radiographic studies, and pre- and post-operative serum alkaline phosphatase (ALP) levels were evaluated. Molecular and histochemical analyses of ALP were documented in one case of clear cell chondrosarcoma.

RESULTS

Pre-operative serum ALP levels were elevated in 3 patients, and were normal in another 3 patients. After removal of the tumors, the enzyme levels decreased in all patients and returned to normal in 3 patients, who had pre-operative high ALP levels. Enzyme histochemical and molecular analyses demonstrated that the tumor produced ALP.

CONCLUSION

Clear cell chondrosarcoma produces ALP, which can be used as a tumor marker in diagnosis and follow-up.

In vivo bone-forming capacity of human bone marrow-derived stromal cells is stimulated by recombinant human bone morphogenetic protein-2

In the present study, we investigated whether the in vivo bone-forming capacity of human bone marrow-derived stromal cells (HMSCs) could be enhanced by recombinant human bone morphogenetic protein-2 (rhBMP-2). The HMSCs obtained from seven donors (5-54 years of age) were passaged three to six times. Passaged HMSCs exhibited the osteoblastic phenotype in vitro, including: (a) an increase in alkaline phosphatase (ALP) activity in response to dexamethasone, ascorbic acid, and beta-glycerophosphate: and (b) mRNA expression for markers of osteoblastic lineage (ALP, osteopontin, osteocalcin, and parathyroid hormone-receptor) and BMP-2, -4, and -6 detected by reverse transcription-polymerase chain reaction. For the in vivo assay, transplants were subcutaneously implanted into nude mice as follows: group A (vehicle); group B (rhBMP-2); group C (HMSCs with vehicle); and group D (HMSCs with rhBMP-2). Transplants were obtained 2 and 4 weeks after implantation. Correlated radiographic findings, histological observations, and in situ hybridization using species-specific probes showed that the group B transplants contained bone tissue of mouse origin, which was observed at the periphery of the transplants. Four weeks after implantation, small amounts of HMSCs-derived bone tissue were detected at the periphery in two of seven transplants in group C. In contrast, five of seven group D transplants exhibited HMSCs-derived bone tissue, which was located at the center of the transplants and was surrounded by mouse bone tissue. Furthermore, HMSCs-derived chondrogenesis was detected in two of seven group D transplants. The results of the present study demonstrate that culture-expanded HMSCs preserve the osteoblastic phenotype, and the in vivo bone-forming capacity can be promoted by rhBMP-2.

An immunohistochemical study on cathepsin D in human hippocampus

Cathepsin D is a lysosomal enzyme involved in neuronal degeneration. In this study, the immunohistochemistry of cathepsin D was studied in hippocampal CA1 neurons that are vulnerable to ischemia, and parahippocampal glial cells. CA1 neurons from the majority of cases showed cathepsin D immunoreactivity in the cytoplasm, whereas shrunk neurons were unstained in only one case. There was no statistically significant correlation between the postmortem interval between death and autopsy, and cathepsin D immunoreactivity in CA1 neurons. These observations indicate that cathepsin D immunoreactivity is not a sensitive marker for neuronal degeneration or postmortem changes. On the other hand, there was a statistically significant correlation between age and cathepsin D immunoreactivity in the cytoplasm of parahippocampal glial cells. This shows that senescence is correlated with cathepsin D expression in humans as has been reported previously in an animal study.