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Biomedical subjects

K Kusuzaki

Publications and source records attributed to K Kusuzaki.

At least 19 recordsLinked to original sources
PubMed2001

Extraskeletal osteosarcoma arising in myositis ossificans.

A 53-year-old woman had extraskeletal osteosarcoma that developed from a soft tissue bony mass present on the volar aspect of the left wrist for 4 years. Initially, the bony mass was soft and movable, but during the first year it became hard and fixed. The patient had no history of trauma. Because the lesion did not grow or cause any symptoms, the patient did not come to the hospital until 4 years after she first noticed the lesion. Radiologically, the bony mass had features characteristic of mature myositis ossificans, showing "eggshell" ossification. A nonmineralized soft tissue mass occurred between the surface of the radius and the bony shell. Histologically, a high-grade osteosarcoma was present between the surface of the radius and the well-differentiated bone tissue, which included fatty and hematopoietic marrow. All the findings indicated that our patient had an extremely rare case of malignant transformation of myositis ossificans.

Female↗
PubMed2001

Ceramic endoprosthesis for aggressive giant cell tumors near the knee: eight cases followed for more than 10 years.

Eight patients with locally aggressive giant cell tumor were treated with marginal resection and implantation of a ceramic endoprosthesis with a non-hinged knee joint. The patients have been followed-up for between 10 to 16 years. Newly formed bone appeared at the junction between implant and cortex and in 2 cases subsidence of the implant was seen. All the patients had good function of the knee and no revision was needed.

Adult↗
PubMed2001

Acridine orange induces binucleation in chondrocytes.

OBJECTIVE: Although it is well known that binuclear cells commonly appear among the chondrocytes of normal cartilages as well as among neoplastic chondrocytes of chondrosarcomas, the mechanism of binucleation is still unclear. Therefore, this study was undertaken to clarify the mechanism of binucleation in chondrocytes, using primary culture cells of growth plate cartilage. DESIGN: These chondrocytes were exposed to acridine orange (AO) which is a fluorescent dye for differentiating certain DNAs and RNAs in nuclei and cytoplasm, and which inhibits mitosis. After exposure to 0.5 microg/ml AO, for 0, 6, 24, 48, and 96 h, the following parameters were investigated: (1) cell growth rate (GR); (2) frequency of hyperdiploid cells (%HDC) by DNA cytofluorometry; (3) mitotic index (MI); (4) BrdU labeling index (LI); (5) frequency of binuclear cells (%BNC). RESULTS: Compared with the control cells, which were cultured in AO-free medium, the GR was remarkably inhibited at 24 h. MI was also decreased from 6 to 24 h, and LI decreased at 48 h. However, these parameters were recovered at 96 h. The %HDC was increased from 6 to 96 h, and the %BNC was also increased to a maximum of six times that of the control cells at 96 h. DISCUSSION: These results suggested that the binuclear cells observed among the cultured chondrocytes may be formed from G2 arrested cells by amitotic nuclear division, but not by mitosis without cytoplasmic division or cell fusion.

Acridine Orange↗
PubMed2001

DNA cytofluorometric analysis of chondrocytes in human articular cartilages under normal aging or arthritic conditions.

OBJECTIVE: Since most chondrocytes in articular cartilage are in the resting phase (G0) of the cell cycle, it has been difficult to investigate their cell kinetics using 3H-thymidine autoradiography, or immunohistochemistry. In the present study, DNA cytofluorometry, which is useful to analyse the cell kinetics even for such inactive cell populations as in the G0 phase, was applied to human chondrocytes of the articular cartilages under normal aging and pathologic conditions such as osteoarthritis (OA), rheumatoid arthritis (RA), and aseptic necrosis (AN). DESIGN: The human articular cartilages for the study were obtained from autopsy and surgical materials. Fifty joints were used for the study of aging, 54 for the study of OA, 20 for studying RA, and 10 for AN study. The isolated chondrocytes were quickly prepared from fresh articular cartilages, using a combination method of enzymatic digestion with papain and collagenase, followed by mechanical cell separation by churning and homogenization. RESULTS: The DNA histograms obtained by cytofluorometry with propidium-iodide staining showed that most chondrocytes had diploid DNA content (2c) in all cartilages studied, suggesting that they were in the G0 phase. However, there were a few chondrocytes having tetraploid DNA content (4c) in the normally aged articular cartilages, and there were some cells having DNA content between 2c and 4c in the diseased cartilages. The former cells were considered to be G0-phase cells of the 4c chondrocytes, while the latter cells were considered to be in the DNA synthetic (S) phase or G2-phase of the 2c chondrocytes. The frequency of 4c chondrocytes in aged cartilage was significantly increased, compared to that in the young cartilage. In contrast to the normal cartilage, the frequency of S- and G2-phase cells, which was expressed as the S- G2 index, in diseased cartilages (OA, RA and AN) was significantly high (P< 0.0001). In OA cartilage, the S-G2 index was much higher in the severe or moderate stage than in the mild stage, suggesting that the chondrocytes in clusters may actively proliferate. CONCLUSION: These results showed that in normal articular cartilages most chondrocytes are in the G0 phase, while some became 4c polyploid cells, and that these G0-phase chondrocytes had a potential to proliferate under diseased conditions.

Adolescent↗
PubMed2000

Bilateral metachronous periosteal tibial amyloid tumors.

Localized primary periosteal amyloid tumors are extremely rare. A case of bilateral tibial amyloid tumor is presented. A 62-year-old woman initially presented with a painful mass in the anterior aspect of the right leg. There was no evidence of underlying systemic disease, including chronic infection or malignancy. Based on the results of resistance with Congo red staining to treatment with potassium permanganate and positivity for kappa light chain, we classified this particular case as AL-type amyloidosis. The patient noticed a swelling in the opposite leg 2 years later. The second tumor was also an AL-type amyloidoma. Amyloid tumors are generally solitary. This is the first case of bilateral periosteal amyloid tumors of the AL-type occurring in the tibiae.

Amyloidosis↗
PubMed2000

Angiomyolipoma arising in the thigh.

A 41-year-old man presented with an asymptomatic mass in the right medial thigh. Magnetic resonance imaging (MRI) revealed a well-demarcated, 10-cm mass in the right adductor muscles. The margins of the mass exhibited high signal intensity and the rest showed low or iso signal intensity on T1-weighted MR images. However, the high signal intensity was decreased on T2-weighted images with fat suppression. The central part of the tumor was of inhomogeneous high signal intensity on T2-weighted images; after Gd-DTPA injection it enhanced in homogeneously on T1-weighted images with fat suppression. On dynamic computed tomography (CT) in the arterial phase, there were strongly enhancing spotty areas in the tumor. At surgery, a yellow-whitish tumor was resected and a pathological diagnosis of angiomyolipoma (AML) in the thigh was made.

Adipose Tissue↗
PubMed2000

Development of bone canaliculi during bone repair.

We recently found that silver impregnation staining with protargol (silver protein), that is, a modified Bodian method, is useful for histologically identifying the details of bone canaliculi structure, using thin sections of decalcified bone tissues. With this staining method, we conducted the present study to assess the development of bone canaliculi during the process of intramembranous ossification using a fracture-like stimulation model of the rat femur. After making a drill-hole in the cortex of the rat femur, decalcified thin sections were obtained after 3, 5, 7, and 14 days by the standard paraffin-embedding procedure. Silver staining for bone canaliculi was performed using our previously reported technique. The results showed that woven bone covered the fracture surface of the cortex after 5 days, then immature lamellar bone attached to the woven bone after 7 days, and finally the lamellar bone matured and became thick with appositional growth after 14 days. The osteocytes in the woven bone appeared at an early stage of bone repair and developed a few canaliculi that were short and irregularly distributed in the osteoid matrix, while the osteocytes in the lamellar bone at a late stage formed many bone canaliculi that were long and regularly distributed in mature bone matrix. Therefore, we concluded that woven bone osteocytes may be necessary for induction of the lamellar bone osteocytes followed by active appositional growth of the lamellar bone at the early stage of bone repair, and also that both bone tissues could be clearly distinguished from one another based on the pattern of development of bone canaliculi by the osteocytes, as seen with the use of our sensitive staining method.

Animals↗
PubMed2000

Osteoblastic differentiation and P-glycoprotein multidrug resistance in a murine osteosarcoma model.

A recent study of multidrug resistance (MDR) 1 gene transfected osteosarcoma cells found a cause-effect relationship between increased expression of P-glycoprotein (P-gp) and a low aggressive phenotype. However, several experimental and clinical studies have observed contradictory findings in that P-gp expression has been associated with tumour progression. In the present study, we characterized P-gp-positive and P-gp-negative single-cell clones of a murine osteosarcoma, to further investigate the relationship between P-gp expression and changes in cell phenotype. Although these clones were all selected by doxorubicin (DOX) exposure, they were heterogeneous with respect to MDR1 gene expression. The P-gp-positive clones revealed MDR phenotype, whereas the P-gp-negative clones showed no resistance to drugs. Morphological and functional analysis showed that both the P-gp-positive and P-gp-negative clones were more differentiated than the parent cells in terms of enhanced activity of cellular alkaline phosphatase, an increase in well-organized actin stress fibres and enhanced osteogenic activity. Moreover, these subclones all displayed a decrease in malignant potential such as oncogenic activity, tumour growth rate and metastatic ability, regardless of their P-gp status. These results indicate that the observed osteoblastic differentiation and less aggressive phenotype in DOX-selected osteosarcoma cells may not only be explained by the direct effect of P-gp, and accordingly, consideration of the effect of DOX, as well as P-gp, appears to be important.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2000

Photodynamic inactivation with acridine orange on a multidrug-resistant mouse osteosarcoma cell line.

Overcoming multidrug resistance (MDR) is an urgent issue to improve the prognosis of osteosarcoma patients. In this study, we undertook to clarify the effect of photodynamic therapy (PDT) with acridine orange (AO) on the MDR mouse osteosarcoma (MOS / ADR1) cell line, by comparing the outcome with the effect on a chemosensitive osteosarcoma (MOS) cell line. Cultured cells of MOS and MOS / ADR1 cell lines were exposed to AO at various concentrations for various times, followed by long- or short-term (10 or 1 min) illumination with blue light (466.5 nm) for excitation. Living cells were counted by means of the trypan blue exclusion test. The results showed that AO rapidly bound to DNA, RNA and lysosomes of living MOS and MOS / ADR1 cells and also that most tumor cells in both cell lines died rapidly (viability ratio to untreated cells: 1/1000) within 48 h under conditions of continuous or 15-min flash exposure to AO at concentrations above 1.0 microg/ml plus 10-min illumination with blue light. Even after flash exposure to AO at concentrations above 1.0 microg/ml plus 1-min illumination, the viability of MOS/ADR1 cells decreased to a viability ratio of less than 1/ 1000 within 72 h. Based on these results, we concluded that AO with photo-excitation has a strong cytocidal effect, not only on chemosensitive mouse osteosarcoma cells, but also on MDR mouse osteosarcoma cells. These results suggested that photodynamic therapy with AO may be a new approach to treating MDR human osteosarcomas.

Acridine Orange↗
PubMed2000

Total tumor cell elimination with minimum damage to normal tissues in musculoskeletal sarcomas following photodynamic therapy with acridine orange.

Acridine orange (AO) has unique biological actions enabling tumor visualization (fluorovisualization) and a strong cytocidal effect (photodynamic therapy: AO-PDT) under illumination with blue light. Accordingly, in this study, we attempted to develop a new surgical technique for total tumor cell elimination using these photodynamic reactions with AO in a mouse osteosarcoma model. The results showed that local tumor recurrence was significantly inhibited (23%) in the group treated with curettage under fluorovisualization and AO-PDT, compared to that (80%) in the control group treated with curettage alone under ordinary light. Therefore, we concluded that the combination of curettage under fluorovisualization and AO-PDT may be useful for total tumor cell elimination with minimum damage to normal tissue in musculoskeletal sarcomas.

Acridine Orange↗
PubMed2000

Intrinsic resistance to chemotherapeutic agents in murine osteosarcoma cells.

BACKGROUND: There are two general categories of drug resistance: acquired and intrinsic. The mechanisms involved in acquired drug resistance have been extensively studied, and several mechanisms have been described. However, the mechanisms responsible for intrinsic drug resistance have not been elucidated, to our knowledge. The purpose of the present study was to investigate the cytological and biochemical differences between acquired and intrinsic drug resistance in osteosarcoma cells. METHODS: We previously isolated a clonal cell line (MOS/ADR1) to study acquired resistance in osteosarcoma by exposure of parental murine osteosarcoma cells (MOS) to doxorubicin. In the present study, we cloned a new, intrinsically resistant cell line (MOS/IR1) by single-cell culture of MOS cells and we investigated the differences in cell phenotype and the mechanisms of resistance in both of these resistant clones. RESULTS: The MOS/ADR1 and MOS/IR1 cells were sevenfold and fivefold more resistant to doxorubicin than the parental murine osteosarcoma cells. Morphologically, the MOS/ADR1 cell line was composed of polygonal cells, whereas the MOS/IR1 cell line consisted of plump spindle cells with long cytoplasmic processes. The MOS/IR1 cells showed a much lower level of alkaline phosphatase activity than did the MOS/ ADR1 and MOS cells. There were no substantial differences in the cellular DNA content or the doubling time among these three lines. Overexpression of the P-glycoprotein involved in the function of an energy-dependent drug-efflux pump was detected in the MOS/ADR1 cells but not in the MOS/ IR1 cells. After the cells were incubated with doxorubicin for one hour, the two resistant lines had less accumulation of the drug than did the parent line (p < 0.05). The addition of a P-glycoprotein antagonist, verapamil, or the depletion of cellular adenosine triphosphate resulted in a marked increase in the accumulation of doxorubicin in the MOS/ADR1 cells (p < 0.05) but not in the MOS/ IR1 cells. The MOS/ADR1 cells were found to exhibit cross-resistance only to substrates for P-glycoprotein (such as doxorubicin, vincristine, and etoposide), whereas the MOS/IR1 cells were resistant to all of the drugs studied (including cisplatin and methotrexate). The degree of drug resistance in the MOS/IR1 cells was found to be associated with the molecular weight of the drugs (p < 0.05). Permeabilization of the plasma membrane by saponin increased both the accumulation of doxorubicin (p < 0.05) and the cytotoxic activity of this drug in all lines, but the effects were most pronounced in the MOS/IR1 cells. CONCLUSIONS: Taken together, this data suggests that reduced drug accumulation in the MOS/IR1 cells may be due to the effect of decreased permeability of the plasma membrane on the transport of drugs from the extracellular environment into the cytosol of the cell and that this may be the mechanism responsible for intrinsic resistance to multiple drugs in the MOS/IR1 cell line. CLINICAL RELEVANCE: Current drug treatment for human osteosarcoma may include multiple chemotherapeutic agents, such as doxorubicin, cisplatin, and methotrexate. These drugs exhibit different cytotoxic actions and, thus, the mechanisms of resistance to individual drugs vary. Clinical resistance to multidrug chemotherapy may be observed in tumors that recur after repetitive chemotherapy and in previously untreated tumors. In the former group, a tumor cell may express multidrug resistance by combining several different mechanisms due to its exposure to various drugs. In the latter group, however, this is not likely. Decreased intracellular drug accumulation due to reduced permeability of the plasma membrane, found in the MOS/IR1 cells, is one possible mechanism and may explain the intrinsic resistance to multidrug chemotherapy for the treatment of osteosarcoma. Further study regarding the resistance mechanism in the MOS/IR1 cells may help to overcome the intrinsic drug resistance in oste

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1999

Prognostic value of DNA ploidy response to chemotherapy in human osteosarcomas.

We analyzed the DNA ploidy alterations after preoperative chemotherapy in 30 patients with non-metastatic osteosarcomas of the extremities. All of the patients received intensive chemotherapy with doxorubicin, cisplatin and methotrexate as well as wide tumor resection. DNA ploidy was determined by DNA cytofluorometry using isolated and smeared cells from biopsied and resected tumors after preoperative chemotherapy. The results showed that 12 diploid and nine non-diploid osteosarcomas did not change their ploidy pattern, but nine non-diploid tumors changed to a diploid pattern with the disappearance of the aneuploid cells. The nine patients with altered ploidy tumors had a better histologic response to chemotherapy and a better prognosis than the patients with non-altered tumors especially diploid tumors (P = 0.0138). Therefore, we conclude that a decrease in aneuploid cells after chemotherapy is closely correlated with a good prognosis in half of the cases of aneuploid osteosarcoma. These results also suggest that aneuploid cells are more chemosensitive than diploid cells in human osteosarcomas.

Adolescent↗
PubMed1999

Relationship between chromosomal aberrations by fluorescence in situ hybridization and DNA ploidy by cytofluorometry in osteosarcoma.

An analysis of the chromosomal aberrations and DNA ploidy in the interphase nuclei of seven human osteosacomas was preformed by double-target fluorescence in situ hybridization (FISH) and DNA cytofluorometry. The FISH study of the numerical aberrations in chromosomes 1 and 17 or the structural aberrations in chromosome arm 1p or 17p was carried out by using four locus specific DNA markers, with one pair consisting of 1q12 and 1p36 and the other pair consisting of the 17 cemtromere and 17p13.3. There was no significant differences in the percentage of deletions in chromosome 1 and 17 between osteosarcomas and normal tissues. However, all seven tumors studied had extra copies. Cells with more than three probe signals were regarded as having chromosome polysomy. The percentage of polysomy of chromosome 1 was 20.0-64.0%, and chromosome 17 was 28.0-60.0%. The DNA ploidy patterns of hyperdiploid cells showing a greater DNA content than diploid cells were obtained by DNA cytoflurometry. Five of the seven tumors were non-diploid, and the remaining two were diploid. The percentage of polysomy was correlated with the percentage of hyperdiploid cells in each tumor. Thus, these findings indicated that the DNA ploidy changes were closely correlated with aberrations in the chromosome copy number in osteosarcomas.

Adolescent↗
PubMed1999

Response of DNA ploidy to chemotherapy in primary and metastatic lesions in human osteosarcomas.

Primary and pulmonary metastatic and pulmonary metastatic tumors (two synchronous and seven metachronous metastases) in nine patients with osteosarcomas were studied by DNA cytofluorometry. All patients were treated with both pre and postoperative chemotherapy. The results showed that all five diploid osteosarcomas and three of the four aneuploid tumors did not markedly change their ploidy pattern after preoperative chemotherapy, and had almost the same ploidy patterns as the pulmonary metastatic lesions. Those eight tumors showed poor histologic response and chemoresistance by the doxorubicin binding assay. Only one aneuploid osteosarcoma showing good histologic response and chemosensitivity changed its ploidy pattern to diploid, with the disappearance of aneuploid tumor cells and its synchronous pulmonary metastatic tumor also showed conversion to a diploid pattern with massive tumor necrosis. It is evident that those tumors showing no change in their ploidy pattern after chemotherapy were resistant to the chemotherapy. Therefore, we conclude that regardless of whether the pulmonary metastatic tumors were synchronous or metachronous, they showed the same change in their ploidy pattern as well as their chemosensitivity as the primary human osteosarcoma from which they were derived.

Adolescent↗