Yoshizumi Miyauchi

Vascularized fibular graft for reconstruction of the wrist after excision of giant cell tumor.

&NA; Seven patients with a giant‐cell tumor involving the distal end of the radius were treated with en bloc resection and reconstruction with a free vascularized fibular graft. Two patients with stage 2 disease of Ennekings surgical staging and grade 2 of Campanaccis radiographic grading system were reconstructed with an articular fibular head graft. Five patients with stage 3 and grade 3 disease underwent wrist arthrodesis using fibular shaft transfer. There was radiographic evidence of bone union at the host‐graft junctions in all cases. No local recurrence was seen in any of the patients at the most recent follow‐up examinations. There were six good and one excellent functional results. Wrist arthroplasty using a vascularized fibula head graft is the best procedure for a stage 2 or grade 2 giant‐cell tumor of the distal end of the radius. In cases of stage 3 or grade 3 disease, wrist arthrodesis using a vascularized fibular shaft graft is indicated.

Electron microscopic evidence of a viral nature for osteoclast inclusions in Paget's disease of bone

Circumstantial evidence from electron microscopic and immunological studies support the view that Pagets disease of bone represents a slow virus infection. However, there is only limited information available regarding its electron microscopic, enzyme and immunocytochemical characteristics. Two cases were studied using electron microscopy with particular emphasis on the inclusions in osteoclasts. Detailed ultrastructural and cytochemical studies including immuno-electron microscopy were performed. Some osteoclasts demonstrated specific virus-like structures composed of aggregations of microtubules in the nucleus and cytoplasm. The structures were easily digested by trypsin or protease, and were sensitive to RNase, which provided substantial evidence of a proteinaceous nature and inclusion of ribonucleic acid. Immunocytochemical examination identified binding of anti-respiratory syncytial virus and anti-measles virus antibodies in the tissue obtained from one of the two cases examined. The presence of viral antigens in structures in the cytoplasm of Pagetic osteoclasts supports the theory of paramyxovirus involvement in this disease.

Heterogeneous pattern of gene expression in cloned cell lines established from a rat transplantable osteosarcoma lung metastatic nodule

We have established three cloned cell lines (COS1NR, COS2NR and COS4NR) from the lung metastatic nodule of a highly metastatic variant of rat transplantable osteosarcoma, C-SLM. All three clones shared the same morphological characteristics and tumorigenicity, but their growth rates in vitro and metastatic ability in vivo differed from each other. Single-strand conformation polymorphism (SSCP) analysis revealed all three clones to have the same p53 gene mutation and parent C-SLM tumor. On the other hand, Northern blot analysis showed a different pattern of expression for the genes, c-fos, c-jun, c-Ha-ras, transin (rat stromelysin), bone Gla protein (osteocalsin) and nm23/NDP kinase. These results indicate the presence of a heterogeneous cell population in terms of the different pattern of gene expression in a lung metastatic nodule of rat osteosarcoma and the present newly established cell lines will be useful for further investigation of the biological behavior of osteosarcomas.

Ultrastructural lipid and glycoconjugate cytochemistry of membranous lipodystrophy (Nasu-Hakola disease).

In order to assess the lipid and glycoconjugate characteristics of membranous lipodystrophy, a 29-year-old male with this disease was studied using an ultrastructural cytochemical approach. The specific membranocystic lesions of the disease are composed of cystic spaces and the lining membranes. The membranes were observed to have a two-layered character: microtubular structures in the layer adjacent to the spaces and a central amorphous zone. Lipid staining and the lipase digestion test revealed triglycerides localized not only in the cystic spaces but also in the microtubular structures. Lectin histochemical examintion of carbohydrate components demonstrated thatMaclura pomifera agglutinin bound strongly to the membranes, whileGriffonia simplicifolia I,G. simplicifolia II,Concanavalia ensiformis andTriticum vulgaris agglutinin reacted weakly. Our results indicate the presence of triglycerides and carbohydrates with mainlyα-D-galactose residues in the distinctive membranocystic lesions, in particular in the microtubular structures.

Osteoclast Origin of Giant Cells in Giant Cell Tumors of Bone: Ultrastructural and Cytochemical Study of Six Cases

To clarify the histogenesis of giant cells appearing in giant cell tumors of bone (GCTB), an ultrastructural and cytochemical study of six cases was performed with both acid phosphatase (ACPase) and tartrate-resistant acid phosphatase (TRACPase) as marker enzymes. TRACPase is considered a specific marker for osteoclasts. ACPase was demonstrated in the macrophagelike stromal cells, the multinucleated giant cells, and the infiltrating macrophages. The enzyme reaction was localized in lysosomal dense bodies and Golgi areas. Intense TRACPase activity was demonstrated in the multinucleated giant cells, whereas a weak reaction was found in the macrophagelike stromal cells. The multinucleated giant cells and macrophagelike stromal cells resembled osteoclasts with regard to the subcellular localization of TRACPase. The present results suggest that the giant cells in GCTB are indeed derived from osteoclasts.

Telomerase activity correlates with growth of transplantable osteosarcomas in rats treated with cis-diammine dichloroplatinum or the angiogenesis inhibitor AGM-1470

To determine the role of telomerase activity in the growth of tumors in rats undergoing chemotherapy, a comparison of the volumes of telomerase‐positive transplantable osteosarcomas was made in rats treated with the antineoplastic agent cis‐diammine dichloroplatinum (CDDP) or the angiogenesis inhibitor O‐(chloroacetylcarbamoyl)fumagillol (AGM‐1470). Male F344 rats, 8 weeks old, received transplants of macroscopic lung metastatic nodules into the subcutaneous back space and treatment was started on day 14 thereafter. CDDP was injected i.v. at doses of 0, 0.625, 1.25 and 2.5 mg/kg body weight (b.w.) and AGM‐1470 was administered at total doses of 0, 2.5, 5 and 10 mg/kg b.w. over 2 weeks by osmotic pumps, also implanted into the subcutaneous back space, but remote from the transplanted tumors. On day 28, all animals were killed for measurement of transplanted tumor size and determination of telomerase activities by telomeric repeat amplification protocol (TRAP) assay. The results showed telomerase activity to be highly correlated with the treated/non‐treated (T/C) tumor size ratio (r=0.96, P<0.0001). In a second experiment, CDDP at 2.5 mg/kg b.w. and AGM‐1470 at 10 mg/kg b.w., these being the most effective doses, were given as in the first experiment, and animals were serially killed on days 14, 21, 28, 35 and 42. Tumors in rats treated with CDDP and AGM‐1470 showed 18.2% and 20.5% of the control telomerase activity on days 35 and 21, respectively, when tumor growth was inhibited. However, on day 42, the activities increased to 46.5% and 92.5%, this correlating with re‐growth (r=0.73, P<0.0001). These results suggest that decline of telomerase activity may be involved in tumor growth retardation induced by chemotherapeutic agents. This possibility clearly warrants further mechanistic studies.

Neural crest origin of clear cell sarcoma of tendons and aponeuroses: ultrastructural and enzyme cytochemical study of human and nude mouse-transplanted tumours

In order to clarify the histogenesis of clear cell sarcoma of tendons and aponeuroses (CCS), two cases of human and one nude mouse-transplanted CCS line were studied using an ultrastructural and enzyme cytochemical approach. Most of the tumour cells obtained from the primary and transplanted CCS demonstrated melanosomes in various stages of development within the cytoplasm, whereas no melanosomes could be identified in the metastatic CCS. However, cholinesterase and tyrosinase activities could be demonstrated not only in the melanotic primary and transplanted CCS but also in the amelanotic metastatic CCS. The results therefore support the hypothesis that CCS is a soft tissue tumour derived from the neural crest.

Increased telomerase activity is not directly related to metastatic potential in rat transplantable osteosarcomas

Previously, we reported the establishment of two transplantable osteosarcomas in rats, one induced by local application of a carcinogen, 4-hydroxyamino quinoline 1-oxide (4-HAQO), and another which developed spontaneously, and their subdivision into four lines with high and low metastatic potential to the lung. In the present study, activation of telomerase was investigated by the telomeric repeat amplification protocol (TRAP) assay followed by densitometric quantification. Telomerase activity was found to be elevated in all four lines without any link to the metastatic potential. Thus the spontaneous osteosarcoma (SOS) and derived metastatic lesions (S-SLM) demonstrated a 20.1-23.5-fold increase and the chemical carcinogen (4HAQO)-induced osteosarcoma (COS) and metastatic lesions (C-SLM) were 18.4-19.1-fold elevated as compared to the value for abdominal muscle. The results suggest that activation of telomerase occurs in rat osteosarcomas but that it is not directly involved in determining their metastatic potential.

p53 mutation and absence of mdm2 amplification and Ki-ras mutation in 4-hydroxyamino quinoline 1-oxide induced transplantable osteosarcomas in rats

Previously, we reported the establishment of two transplantable osteosarcomas, one induced by local application of a carcinogen, 4-hydroxyamino quinoline 1-oxide(4-HAQO), and another which developed spontaneously in rats, and their subdivision into four lines with high and low metastatic potential to the lung. In the present study, mutations of p53 and Ki-ras genes were investigated by PCR and SSCP followed by direct sequencing, and the amplification of the mdm2 gene was assessed by Southern blot analysis. Mutations of p53 in exon 7 were detected in 4-HAQO-induced transplantable osteosarcomas, but not their spontaneous counterparts, irrespective of the metastatic potentials. Direct sequencing revealed a CGC to CAC transition with an amino acid change of Arg to His, at codon 246. Neither Ki-ras mutations nor mdm2 amplification were detected in any of the transplantable tumors. The results suggest that while p53 mutations occurred during osteosarcoma development by 4-HAQO without mdm2 amplification and Ki-ras mutation does not contribute to osteosarcoma development in rats.

Ultrastructural cytochemical demonstration of proteoglycans and calcium in the extracellular matrix of chondroblastomas

To clarify the characteristics of the extracellular matrix of chondroblastomas, six cases were studied under the electron microscope, with special reference to proteoglycans and calcium in the cellular areas. In ruthenium hexammine trichloride (RHT)-stained sections the matrix was observed to be composed of rounded or polygonal fine granules and unbanded thin filaments that appeared to link neighboring granules together. Treatment with potassium-pyroantimonate showed intracellular accumulation of precipitates, mainly localized within the cisternae of the rough endoplasmic reticulum as well as in the extracellular matrix. The presence of calcium in the precipitates was confirmed using x-ray energy dispersive analysis. These findings, similar to characteristic features observed in calcifying systems, support the theory that chondroblastomas are of chondrogenic origin.