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Biomedical subjects

Y Kotoura

Publications and source records attributed to Y Kotoura.

At least 91 records · Page 5Linked to original sources
PubMed1987

Benign osteoblastoma of the cervical vertebra.

A 31-year-old patient, with a relatively uncommon benign osteoblastoma of the sixth cervical vertebra, exhibited symptoms of spinal cord compression. Computed tomographic metrizamide myelography was very useful in the preoperative planning, particularly for locating the position and extent of the lesion. The tumor was totally removed via posterior and anterior approaches in a two-stage operation. Roentgenograms, taken 1 year and 6 months postoperatively, showed good bony union with no evidence of tumor recurrence.

Adult↗
PubMed1987

Localization of human osteogenic sarcoma xenografts in nude mice by a monoclonal antibody labeled with radioiodine and indium-111.

Monoclonal antibody OST7 reacts specifically with human osteogenic sarcoma. Whole immunoglobulin G (IgG) and the F(ab')2 fragment of OST7 were labeled with radioiodine and indium-111 (111I), and injected into athymic nude mice bearing xenografts of human osteogenic sarcoma (KT005). All radiolabels retained their antigen-binding activities allowing clear visualization of transplanted tumors. Tissue distribution, however, varied. The net tumor concentration of 111In-lableled whole IgG was higher and was retained longer than that of radioiodinated one, but 111In-labeled antibody showed a lower tumor-to-liver and tumor-to-kidney ratio. In radioiodinated OST7, F(ab')2 fragments provided much better images with much higher tumor-to-tissue ratios than whole IgG. Using F(ab')2 fragments as a carrier for 111In, little image improvement was obtained due to the high radioactivity in the liver and kidney. The different distributions among these radiolabels suggest that the choice between intact igG and F(ab')2 fragments and between radioiodine and 111In depends on the intended use.

Animals↗
PubMed1987

[Application of biomaterials in the treatment of osteosarcoma].

Eight patients with osteosarcoma was treated with an endoprosthetic replacement in combination with chemo- and radiotherapy. Among the 8 patients, 5 died because of lung metastasis but no local recurrence was observed. The functional evaluations of the surgical treatment were 3 excellent, 2 good and 2 poor and the device evaluations were: 4 good and 4 fair. For treatment by prosthetic replacement, the distal femur is the best site, while in proximal tibia, there is difficulty in attachment of the patellar ligament. Usually a hingeless prosthesis is better than a hinge type, but if the tumor resection is wide, a hinge type is better because it can give more stability. Among metals used, titanium alloy is better, while among ceramic materials alumina is good the type of material depending on the location and size of tumor resection. New biomaterials are being used more often in the treatment of osteosarcoma and in the future biomaterials will be not only applied in artificial joint but also in the repair or replacement of soft tissue and for various other purposes.

Adolescent↗
PubMed1986

Recognition of serum alkaline phosphatase by murine monoclonal antibodies against human osteosarcoma cells.

Using OST6 and OST7 monoclonal antibodies against human osteosarcoma cells, a solid-phase radioimmunosandwich assay was developed to quantitate a human osterosarcoma-associated antigen in a total of 242 sera from healthy adults and patients with various diseases. The levels of the antigen in sera were high in patients with osteosarcoma and in children without tumorous diseases compared with healthy adults; however, the highest level of the antigen was found in patients with obstructive jaundice. The quantity of the antigen correlated with serum alkaline phosphatase (EC 3.1.3.1.) activity, and showed a strong correlation (correlation coefficient, 0.94) in 50 sera. Immunolocalization of enzyme activity assay using monoclonal antibodies was performed to ascertain whether the antigen had alkaline phosphatase activity. This assay proved that OST6, OST7, and OST15 monoclonal antibodies recognized serum alkaline phosphatase; furthermore, these monoclonal antibodies seemed to react with not only the bone isoenzyme but also the liver isoenzyme.

Alkaline Phosphatase↗
PubMed1985

Malignant fibrous histiocytoma of bone. A review of 13 cases and an ultrastructural study.

Observations on 13 patients with primary malignant fibrous histiocytoma of bone were reported. Included were nine male and four female patients, ranging in age from 6 to 81 years (mean, 44.8 years). Pain was the most common complaint. The interval from the first symptom to the initial treatment varied from 2 months to 20 years. Seven tumors arose in the knee region. Roentgenologically, most of the lesions presented with an osteolytic and destructive appearance. Histologically, highly variable morphologic features existed. The storiform-pleomorphic pattern was found in every tumor, although it was not necessarily pathognomonic for malignant fibrous histiocytoma of bone. Surgery, radical or incomplete, was the primary treatment for all but one patient. Lymph node metastasis was present in three. Five patients died of the disease from 3 to 79 months after the diagnosis (mean, 28 months), all exhibiting metastasis to the lung. Gaucher's body-like structure demonstrated in the electron microscopic study shows the histiocytic quality of malignant fibrous histiocytoma of bone.

Adult↗
PubMed1985

A method for toxicological evaluation of biomaterials based on colony formation of V79 cells.

This report describes a method for cytotoxicity screening of biomaterials based on colony formation of V79 cells. For this test, two metals (titanium and nickel), two ceramics (alumina ceramic and tricalcium phosphate), and two types of polymeric material [high density polyethylene (HDP) and polyvinylchloride (PVC)] were used. Each metal and ceramic was cast into a disk and semidisk 49 mm in diameter and 1 to 2 mm thick. The HDP was molded into a petri dish and PVC was used as a thin film. The materials were sterilized by heating or with ethylene oxide and placed in plastic petri dishes, after which 8 ml cell suspension containing 100 cells were added to each dish. After 1 week, the colonies formed on the materials were fixed, stained, and then the number of colonies was counted. Titanium, alumina ceramic, and HDP showed no differences from the controls in terms of colonies. On the disks and the semidisks of nickel and tricalcium phosphate and on the thin disks of PVC, however, no colonies were detected. The V79 cells used in this experiment showed a rapid and logarithmically stable growth curve and such a high rate of colony formation as to form visible noticeable colonies, and were therefore suitable cells for screening test the cytotoxicity of biomaterials. Unlike other previously reported methods of in vitro cytotoxicity testing, this method permits assay of colonies formed from a single cell after proliferation directly on the materials. Moreover, the test with semidisks permits simple screening to assess the cytotoxicity is caused by either the chemical substances or the physical properties of the materials.(ABSTRACT TRUNCATED AT 250 WORDS)

Aluminum Oxide↗
PubMed1985

The effects of PGD2 and 9-deoxy-delta 9-PGD2 on colony formation of murine osteosarcoma cells.

Effects of antineoplastic prostaglandins (PG), PGD2 and 9-deoxy-delta 9-PGD2, on colony formation of cloned Dunn osteosarcoma (TA 102), normal Swiss 3T3 and V-79 cell lines were evaluated. PGD2 significantly inhibited the colony formation of TA 102 cells in a dose-dependent manner at concentrations between 0.5 and 5 micrograms/ml. The IC50 value was calculated to be 0.72 microgram/ml. A dose-dependent inhibition of TA 102 colony formation was also observed with 9-deoxy-delta 9-PGD2 between 0.01 to 1 microgram/ml, the IC50 value being 0.22 microgram/ml. These prostaglandins did not exert cytocidal effects in vitro on Swiss 3T3 cells at concentrations between 0.01 to 1 microgram/ml. The two agents had no significant cytocidal effects on V-79 cells except for 9-deoxy-delta 9-PGD2 at a concentration of 5 ug/ml. These results suggest that PGD2 and 9-deoxy-delta 9-PGD2 are considered to have cytocidal activity on Dunn osteosarcoma cells in dosages which do not affect non-malignant cells.

Animals↗
PubMed1985

Is ECT imaging with Tc(V)-99m dimercaptosuccinic acid useful to detect lung metastases of osteosarcoma?

ECT imaging, using Tc(V)-99m dimercaptosuccinic acid [Tc(V)-DMS] was performed in two patients with lung metastasis of osteosarcoma, and the results were compared with those of CT scan. Clear accumulation of Tc(V)-DMS was recognized in all cases in the same area that CT scans demonstrated. Tc(V)-DMS was labeled under optimal pH 8, had very low SnCl2 concentrations, an equilibrium between a stable form and a dissociated form of anion TcO4(3-) structurally similar to PO4(3-), and was postulated for tumor uptake. Considering this proposed mechanism for Tc(V)-DMS uptake by tumor cells, ECT imaging using this tracer could be of use in the early detection of lung metastasis of osteosarcoma.

Adolescent↗
PubMed1985

Accurate localization of insulinoma using percutaneous transhepatic portal venous sampling--usefulness of simultaneous measurement of plasma insulin and glucagon levels.

By means of percutaneous transhepatic portal venous sampling (PTVS), plasma insulin and glucagon levels were determined simultaneously at various sites of the hepatic portal venous system in two patients with insulinoma and four patients without. In the two cases of insulinoma, an obvious rise of insulin concentration was observed at the vicinity of the tumour, while glucagon levels were not elevated in the blood samples showing an insulin peak. In the remaining four cases without evidence of insulinoma, significant step-ups of plasma insulin occurred in the splenic vein as well, but were accompanied with concomitant elevation of plasma glucagon levels in the same blood samples. Thus, by measuring insulin alone, false positive data may frequently be obtained when PTVS is performed on patients with suspected insulinomas. The simultaneous measurement of insulin and glucagon might be helpful in avoiding such errors.

Adenoma, Islet Cell↗
PubMed1985

Osteosarcoma with multiple intramuscular metastases. A case report.

A 21-year-old man with an osteosarcoma in the proximal tibia was treated by amputation, radio- and chemotherapy. Besides pulmonary metastases, intramuscular metastases repeatedly developed. Cell culture studies of pulmonary and muscular tumors showed different sensitivity patterns for cytostatic drugs; the therapy may have selected different subpopulations of the primary tumor.

Adult↗
PubMed1984

Monostotic fibrous dysplasia in the femoral neck. A clinicopathologic study.

In eight patients with monostotic fibrous dysplasia in the femoral neck, the lesion was virtually limited to the neck region without any extension into the shaft. In one patient with symptoms of 40 years' duration and another with a recurrent lesion, there was a deformity in the neck of the femur. A pathologic fracture, including a minor one, was identified in two patients. Roentgenographically, the lesion should be distinguished from various entities producing a localized central region of rarefaction in the proximal femur. The histologic features of fibrous dysplasia are characteristically diagnostic. Six of the eight patients were successfully treated by curettage and bone graft. There was no evidence of malignant transformation.

Adolescent↗
PubMed1983

Osteofibrous dysplasia (ossifying fibroma of long bones). A study of 12 cases.

Osteofibrous dysplasia (ossifying fibroma of long bones) is one of the fibro-osseous lesions that affects the tibia and fibula in the first decade of life. A study of 12 patients with this lesion showed the high rate of recurrence after surgical intervention. Most commonly, the lesions are eccentrically located in the diaphysis of the tibia. Pseudarthrosis may develop in cases where the lesion is situated in the distal portion. Roentgenologic and histopathologic features are basically similar to those of monostotic fibrous dysplasia of long bones. However, bony or osteoid trabeculae covered by osteoblasts enable distinction between osteofibrous dysplasia and monostotic fibrous dysplasia, as determined histologically. The current evidence indicates that surgery should not be attempted in patients under 10 years of age.

Bone Neoplasms↗
PubMed1983

[Histological studies of the effect of intra-operative irradiation on osteosarcoma].

At the Department of Orthopaedic Surgery of Kyoto University Hospital, intra-operative radiotherapy by the high dose electron irradiation has so far been used in treating patients with osteosarcoma. The dose distribution was calculated by CT-number so that the focus was subject to at least 80% of the irradiation doses and the surgically opened lesion was irradiated with 5,000 rad of 12-26 MeV electron beams. In order to accurately assess its therapeutic effect, histological studies were conducted on 9 patients who underwent en bloc resection or amputation following irradiation treatment for osteosarcoma. Method The excised specimen was sagittally cut in half and was fixed in 10% neutral buffered formalin. The specimen was cut into 5 mm thick sections corresponding to CT cross sections. At the border region between irradiated and non-irradiated fields, specimens were prepared using sagittal sections to compare the histological findings of both fields. After all specimens were carefully macroscopically examined and then photographed with soft-X-ray film, some of them were prepared as non- delimed specimens in polyester resin and were observed by contact microradiography and fluorescent microscopy. The remaining specimens after deliming in Plank - Rychlo solution were sliced to 4-8 micron thick for study as large specimen stained with hematoxylin and eosin. Four patients had been administered tetracycline 3 days preoperatively. Results Histologically the changes of the specimens were evaluated using the Oohoshi and Shimosato 's criteria for the histological effects of irradiation. In two of the 9 patients, who had received unidirectional irradiation, the survival of Grade 2a-2b tumor tissue was observed in the superficial layers both inside and outside the periosteum. Six patients who were irradiated from both sides or three directions, showed complete necrosis in extremely small areas of Grade 2b-3 change of tumor cells. Only one of these 9 patients had a local recurrence after the irradiation. Marked fluorescence was observed in the recurrent tissue by tetracycline labeling, but no fluorescence was observed in any of the other cases in the tumorous tissues which had fallen within the range of irradiation. These findings strongly suggest that intra-operative irradiation is extremely effective in controlling local osteosarcoma lesion in the extremities.

Adolescent↗