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Biomedical subjects

Tetsuya Nakatani

Publications and source records attributed to Tetsuya Nakatani.

At least 19 recordsLinked to original sources
PubMed2005

Establishment and characterization of a KIT-positive and stem cell factor-producing cell line, KTHOS, derived from human osteosarcoma.

Osteosarcoma is a malignant bone tumor that commonly affects adolescents and young adults. In the present study a human osteosarcoma cell line, KTHOS, was established from a primary osteosarcoma lesion in the distal femur of a 16-year-old girl. After 106 passages, the KTHOS cell line retained the biological characteristics of osteosarcoma. The KTHOS cells had spindle to pleomorphic cytoplasm with round to ovoid nuclei containing multiple prominent nucleoli, as expected based on the mesodermic origin of osteoblasts. The KTHOS cells were immunoreactive for osteocalcin, osteonectin, stem cell factor (SCF), and KIT (CD117). Reverse transcriptase-polymerase chain reaction indicated that the KTHOS cell line expressed mRNA for SCF and KIT. The KTHOS cells produced relatively high amounts of soluble SCF as determined by enzyme-linked immunosorbent assay. The results suggest that cell proliferation of the KTHOS cell line might be involved in autocrine and/or paracrine loops of the SCF/KIT signaling system. The KTHOS cell line is a novel human osteosarcoma cell line that releases SCF and expresses KIT. This cell line can be used for studies to explore the mechanisms for oncogenesis of human osteosarcomas.

Adolescent↗
PubMed2004

Expression of transforming growth factor beta isoforms and their receptors in malignant fibrous histiocytoma of soft tissues.

PURPOSE: Transforming growth factor beta (TGF-beta) is a multifunctional growth factor that variably affects proliferation, differentiation, and extracellular matrix formation. Little information is currently available on the TGF-beta expression in malignant fibrous histiocytoma (MFH). The aims of the present study were to investigate the expression of TGF-beta isoforms and their receptors in human MFH specimens. EXPERIMENTAL DESIGN: The expression of TGF isoforms, and TGF-beta receptors (TGF-beta R1 and -beta R2) were immunohistochemically evaluated in 43 paraffin-embedded MFH specimens. Furthermore, the correlation of the TGF-beta and receptor expression with tumor proliferative activity assessed by MIB-1 indices was analyzed. RESULTS: Positive immunoreactivity for TGF-beta1, -beta2, and -beta 3 was identified in tumor cells of 42, 40, and 38 of the 43 MFHs, respectively. In each TGF-beta isoform immunostaining, the specimens were divided into two groups based on the number of positive tumor cells: those with low (<25%) and those with high (>==25%) immunoreactivity. There were no statistically significant differences in the MIB-1 indices between the two groups. Positive immunoreactivity for TGF-beta R1 and -beta R2 was identified in tumor cells of 36 and 24 of the MFHs, respectively. The specimens were divided into two groups based on their receptor expression patterns: those with both TGF-beta R1- and -beta R2-positive immunoreactivity (n = 23), and those with both or either TGF-beta R1- and -beta R2-negative immunoreactivity (n = 20). The MIB-1 indices in the both-TGF-beta R1- and -beta R2-positive group were significantly higher than those in the other group (P = 0.0102). There was no significant difference in pulmonary metastasis ratios between the two groups. CONCLUSIONS: These findings strongly suggest an association of the TGF-beta ligand/receptor system with a significantly higher MIB-1 index in human MFHs. Investigation of the TGF-beta R1 and -beta R2 coexpression might be useful in predicting tumor behavior of MFHs.

Activin Receptors, Type I↗
PubMed2004

Apophysitis of the ischial tuberosity mimicking a neoplasm on magnetic resonance imaging.

We present multimodality imaging features of an ischial tuberosity apophysitis in a 13-year-old boy who was an active baseball pitcher. Roentgenography of the pelvis and computed tomography showed mild irregularity in the inferior margin of the left ischial tuberosity. T1-weighted MRI showed a wide area with low signal intensity in the left ischial body; T2-weighted fat-suppression images showed areas with markedly high signal intensity in the ischial apophysis and body and the surrounding periosteum; contrast-enhanced T1-weighted fat-suppression MRI showed that the ischial body, surrounding periosteum, and origin of the hamstring muscles strongly enhanced; technetium-99m scintigraphic scans showed increased isotope uptake in the entire ischial body. Histological specimens obtained from the bone showed increased osteoblastic activity, edema, and proliferation of benign spindle cells and small vessels in the bone marrow spaces. In the present case, because MR imaging demonstrated extensive signal abnormalities involving the apophysis, periosteum, and intramedullary portion of bone, a neoplasm could not be excluded, and a biopsy was undertaken.

Athletic Injuries↗
PubMed2004

Periosteal osteoblastoma of the distal femur.

Osteoblastomas located on the surface of the cortical bone, so-called periosteal osteoblastomas, are extremely rare. We report on a case of periosteal osteoblastoma arising from the posterior surface of the right distal femur in a 17-year-old man. Roentgenographic, computed tomographic, magnetic resonance imaging, and histologic features of the case are presented. Periosteal osteoblastoma should be radiologically and histologically differentiated from myositis ossificans, avulsive cortical irregularity syndrome, osteoid osteoma, parosteal osteosarcoma, periosteal osteosarcoma, and high-grade surface osteosarcoma. Although periosteal osteoblastoma is rare, this tumor should be included in the differential diagnosis of surface-type bone tumors.

Adolescent↗
PubMed2004

Coexpression of hepatocyte growth factor and its receptor c-Met correlates with high MIB-1 proliferative index in malignant fibrous histiocytoma.

Hepatocyte growth factor (HGF) is a multifunctional cytokine that variably affects cell motility, proliferation, and morphogenesis. Little information is currently available on the HGF and its receptor c-Met expression in malignant fibrous histiocytoma (MFH). We immunohistochemically investigated the HGF and c-Met expression in 43 MFH tissue specimens. Furthermore, the correlation of the HGF and c-Met expression with tumor proliferative activity assessed by MIB-1 indices was analyzed. Our results showed that positive cytoplasmic immunoreactivity for HGF and c-Met was identified in tumor cells in 36 (84%) and 20 (47%) of the 43 MFH cases analyzed, respectively. Coexpression of HGF and c-Met was observed in 20 (47%) of the 43 MFHs, and was correlated with high MIB-1 proliferative indices (p = 0.0446). These findings strongly indicate that the HGF/c-Met signaling system plays an important role in promoting cell proliferation of human MFHs via an autocrine loop.

Adolescent↗
PubMed2004

Phalangeal microgeodic syndrome resulting in rapid digital shortening.

Microgeodic phalangeal syndrome is a rare condition affecting the fingers in children. Radiographically, the affected phalanges show sclerosis with multiple small areas of osteolysis. The pathogenesis of microgeodic phalangeal syndrome is considered to be a transient disturbance of the peripheral circulation caused by cold temperatures. In most cases, the symptoms and the radiographic changes return to normal within several months without any treatment. We present a rare case of microgeodic phalangeal syndrome in the middle phalanx of the right index finger in an 8-year-old girl, in whom the affected phalanx shortened within 6 weeks of the initial presentation. It was speculated that minor trauma to the finger might have contributed to the collapse and shortening of the phalanx. The current case indicates that the use of a splint for the affected finger in the early period after onset of symptoms might be recommended to avoid digital shortening.

Bone Diseases↗
PubMed2003

MRI-negative rotator cuff tears.

We report two cases of rotator cuff tear in which the T(2)-weighted MRI signal was negative at the first examination, but positive by the second examination without any changes in symptoms. Many authors have reported on correlations between the MRI and operative findings of rotator cuff tears. However, MRI findings, history of symptoms and operative findings in our patients suggest that there was a discrepancy between symptoms and MRI findings dependent on the period from the injury. Operative findings also indicate that intratendinous tears might have occurred first in these patients then progressed to partial or full thickness tears over time. We concluded that physicians should keep rotator cuff pathology in mind even in patients whose MRI findings are negative but symptoms of rotator cuff tear persist.

Adult↗
PubMed2002

Aspiration biopsy of nodular sarcoidosis of the muscle.

The nodular form of muscular sarcoidosis is rare and the condition is often confused with a soft tissue neoplasm. We present a case of nodular muscular sarcoidosis of the right calf in a 52-yr-old woman which was diagnosed by thin-needle aspiration biopsy (TNAB). In this patient, a calf mass was the initial manifestation of sarcoidosis. Contrast-enhanced computed tomographic scans of the calf showed a mass with peripheral ring-like enhancement. T2-weighted magnetic resonance images demonstrated a mass with central hypointensity and marked peripheral hyperintensity. TNAB revealed noncaseating epithelioid cell granulomas in association with multinucleated giant cells. Combined with the radiologic findings, TNAB is considered a useful modality for the diagnosis of nodular muscular sarcoidosis.

Biopsy, Needle↗
PubMed2002

Scrape and fine-needle aspiration cytology of extraskeletal osteosarcoma.

Extraskeletal osteosarcoma is a rare malignant soft tissue tumor whose cytologic findings are infrequently reported. We describe scrape and fine-needle aspiration biopsy (FNAB) cytology findings of an extraskeletal osteosarcoma in the right shoulder of a 24-yr-old man. Initial computed tomography revealed multiple ossification foci within the lesion. After excision of the primary tumor, the tumor recurred 13 months later. Scrape smears of both the primary tumor and FNAB smears of the recurrent tumor revealed moderate cellularity, cell clusters, and individual cells, closely associated with dense, homogeneous, acellular matrix material. The cells had elongated, oval, or partially bizarre-shaped nuclei with a coarse chromatin pattern and prominent nucleoli. The scrape smears contained large fragments of matrix material consistent with osteoid.

Adult↗
PubMed2002

Reliability of fine-needle aspiration biopsy in the initial diagnosis of soft-tissue lesions.

We retrospectively reviewed fine-needle aspiration biopsy (FNAB) specimens of 301 soft tissue lesions of the extremities and trunk. Final diagnoses were 137 benign and 86 malignant neoplasms and 78 nonneoplastic lesions. Of the 301 FNAB samples, 279 (93%) were adequate for cytologic diagnosis. The adequate FNAB specimens were initially grouped into three broad categories: benign (197 cases), malignant (57 cases), and suspicious for malignancy (25 cases). Sensitivity and specificity for diagnosis of a malignant lesion were 92% and 97%, respectively. The specimens were cytomorphologically classified into nine categories: small round (14 cases), spindle cell (77 cases), epithelioid/polygonal (16 cases), pleomorphic (29 cases), myxoid (19 cases), lipomatous (37 cases), epithelial (23 cases), inflammatory lesions (28 cases), and others (36 cases). Specific FNAB diagnoses were correct in 151 of 279 cases (54%) in combination with clinical and radiologic findings. FNAB is a valuable technique for the primary diagnosis of soft-tissue lesions.

Adolescent↗
PubMed2002

Mechanical stretching force promotes collagen synthesis by cultured cells from human ligamentum flavum via transforming growth factor-beta1.

Although mechanical stress as a result of spinal instability is known to cause hypertrophy of the ligamentum flavum resulting in degenerative spinal canal stenosis, the mechanism of the ligament hypertrophy is not well understood. In the present study, we investigated the effect of mechanical stretching force on collagen synthesis and transforming growth factor-beta1 (TGF-beta1) production using ligament cells isolated from human ligamentum flavum in vitro. Ligamentum flavum cells (LFCs) were isolated from human ligamentum flavum obtained from patients who underwent lumbar spine surgery. The LFCs were subjected to a mechanical stretching force using a commercially available stretching device that physically deformed the cells. Collagen synthesis and TGF-beta1 production levels in the LFCs were then examined. Notable increases were observed in the gene expressions of collagen types I, III, and V in LFCs subjected to mechanical stretching force. The increase in collagen gene expression of LFCs was inhibited in the presence of anti-TGF-beta1 antibodies. Production of TGF-beta1 by the LFCs also increased significantly by the mechanical stretching force. Exogenous application of TGF-beta1 was confirmed to increase collagen synthesis of the LFCs. This data indicated that mechanical stretching force can promote TGF-beta1 production by LFCs, resulting in hypertrophy of the ligament.

Adult↗
PubMedDate not supplied

Subacute osteomyelitis of long bones: diagnostic usefulness of the "penumbra sign" on MRI.

Although subacute osteomyelitis of long bones is not uncommon, it is usually confined to metaphysis. Two unusual cases of subacute osteomyelitis that traversed a growth plate are described. There may be some radiological difficulties in distinguishing it from other malignant or benign lesions. On magnetic resonance (MR) imaging, both of the present cases showed characteristic four-layered appearance and the penumbra sign. These characteristic findings on MR imaging are considered to facilitate establishing the radiologic diagnosis.

Adolescent↗
PubMedDate not supplied

A true intra-articular lipoma of the knee in a girl.

A 16-year-old girl presented with a soft-tissue mass in the anterolateral aspect of her right knee. Magnetic resonance imaging revealed an intra-articular tumor arising from the anterior fat pad of the knee. The tumor showed low signal intensity on T1-weighted images and high signal intensity on T2-weighted images. It was resected under arthroscopic guidance. Grossly, the tumor was composed of soft, yellowish adipose tissue. Pathologic examination revealed a collection of mature adipocytes with marked myxoid changes in the matrix. A diagnosis of lipoma was made. True intra-articular lipomas should be distinguished from lipoma arborescens, which is considered to be a reactive process. In the English language literature, we found only 7 cases of true intra-articular lipoma reported previously. The present case is the youngest patient with such a tumor, and all the previous reports are of the tumor in adult patients. Intra-articular lipoma should be considered in the differential diagnosis of intra-articular masses in adolescents.

Adolescent↗
PubMedDate not supplied

Fine-needle aspiration biopsy in the initial diagnosis of bone lesions.

BACKGROUND: The diagnostic role of fine-needle aspiration biopsy (FNAB) of bone lesions is not yet fully understood. The aim of this study was to examine the diagnostic accuracy and reliability of FNAB of bone lesions. MATERIALS AND METHODS: FNAB smears of 73 lesions obtained from 70 patients with bone lesions were retrospectively reviewed randomly, combined with clinical and radiological findings. RESULTS: Of the 73 FNAB cases analyzed, 67 (92%) were considered to be adequate for diagnosis. The sensitivity and specificity were 100% and 86%, respectively. The positive and negative predictive values were 94% and 100%, respectively. The specific FNAB diagnoses were correct in 63% of the benign group, 89% of the malignant group and 17% of the nonneoplastic group. CONCLUSION: FNAB of bone is a simple, safe, rapid, reliable and cost-effective diagnostic procedure. FNAB is suggested to be helpful in the workup and management of patients with bone lesions.

Adolescent↗