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Featured researches published by Kenshi Sakayama.


Journal of Bone and Joint Surgery-british Volume | 2005

Reconstruction using an autograft containing tumour treated by liquid nitrogen

Hiroyuki Tsuchiya; S. L. Wan; Kenshi Sakayama; Norio Yamamoto; Hideji Nishida; Katsuro Tomita

We describe a method of reconstruction using tumour-bearing autograft treated by liquid nitrogen in 28 patients. The operative technique consisted of en bloc excision of the tumour, removal of soft tissue, curettage of the tumour, drilling and preparation for internal fixation or prosthetic replacement before incubation for 20 minutes in liquid nitrogen, thawing at room temperature for 15 minutes, thawing in distilled water for ten minutes, and internal fixation with an intramedullary nail, plate or composite use of prosthetic replacement. Bone graft or cement was used to augment bone strength when necessary. The limb function was rated as excellent in 20 patients (71.4%), good in three (10.7%), fair in three (10.7%), and poor in two (7.1%). At the final follow-up six patients had died at a mean of 19.8 months after the operation, while 21 remained free from disease with a mean follow-up of 28.1 months (10 to 54). One patient is alive with disease. Bony union was seen at a mean of 6.7 months after the operation in 26 patients. Complications were encountered in seven patients, including three deep infections, two fractures, and two local recurrences. All were managed successfully. Our results suggest that this is a simple and effective method of biological reconstruction.


Journal of Orthopaedic Science | 2008

Histological examination of frozen autograft treated by liquid nitrogen removed after implantation

Yoshikazu Tanzawa; Hiroyuki Tsuchiya; Norio Yamamoto; Kenshi Sakayama; Hiroshi Minato; Katsuro Tomita

BackgroundSeveral oncological sterilization methods involving autoclaving, irradiation, or pasteurization have been developed for limb reconstruction of large bone defects following tumor excision. Studies involving histological examinations of these autografts have all found that osteogenesis occurs slowly. We have used frozen autografts treated by liquid nitrogen for limb reconstruction and have achieved excellent results for bone union. To determine if frozen autografts exhibit early bone remodeling, we investigated the repair processes of the frozen bones.MethodsWe analyzed frozen autografts treated by liquid nitrogen, retrieved at a mean of 19.1 months (2–75 months) after implantation because of complications or local tumor recurrence. The specimens were obtained from six patients with a mean age of 36.2 years (8–68 years). The six grafts comprised three osteoarticular grafts, two intercalary grafts, and one joint graft. We histologically reviewed the autograft-containing sections for tumor cell necrosis, evidence of cortical repair, the cortical junction, and joint cartilage.ResultsTumor cells were completely eradicated from the frozen bone in all cases. In a specimen retrieved 5 months after implantation, a small area of the bone showed active osteocytes and osteoblasts. In three cases retrieved more than 1 year after implantation, osteocytes and osteoblasts were observed in broad portions of the frozen bones, indicating the onset of osteogenesis in the frozen bone at an early stage. The cortical host-graft junction showed incorporation along with continuity of bone trabeculae. In addition, we were able to fi nd normal chondrocytes on the articular surface.ConclusionsThe frozen bone specimens in this study thus showed evidence of newly formed bone and earlier osteogenesis than has been previously reported. Our results suggest that frozen autografts may be considered one of the most useful recycled materials for biological reconstruction.


Spine | 2006

Mesenchymal chondrosarcoma treated with total en bloc spondylectomy for 2 consecutive lumbar vertebrae resulted in continuous disease-free survival for more than 5 years: case report.

Yoshiro Matsuda; Kenshi Sakayama; Yoshifumu Sugawara; Joji Miyawaki; Teruki Kidani; Tatsuhiko Miyazaki; Nozomu Tanji; Haruyasu Yamamoto

Study Design. A case report of an extremely rare malignant spinal tumor successfully treated with total en bloc spondylectomy and chemotherapy. Objective. To describe points for consideration when an osteogenic lesion in the spine is diagnosed and treated. Summary of Background Data. Primary mesenchymal chondrosarcoma in the spine is extremely rare. There were no reports of this tumor being treated with spondylectomy to achieve total surgical resection with a wide margin followed by chemotherapy. Methods. A 44-year-old female presented with low back pain and left flank pain. Magnetic resonance imaging and computerized tomography showed an osteosclerotic tumor of the lumbar vertebrae. Tc-99m HMDP bone scintigraphy was positive, but thallium-201 scintigraphy and gallium scintigraphy were negative. The patient was diagnosed as having chondrosarcoma based on biopsy findings. Results. To resect the tumor completely, total en bloc spondylectomy for 2 consecutive lumbar vertebrae was performed. However, the postoperative pathologic diagnosis was extremely difficult because the patient was initially suspected to have osteosarcoma, but the final diagnosis was mesenchymal chondrosarcoma. Five years after surgery, there have not been any signs of local recurrence or distant metastasis, and the patient has remained continuously disease free. Conclusions. To our knowledge, we reported the first case of mesenchymal chondrosarcoma occurring from the lumbar spine treated with total en bloc spondylectomy and chemotherapy. Successful radical resection of the tumor could be accomplished. Although the effect of chemotherapy on the final results could not be clearly determined, considering that at least continuous disease-free survival was achieved, it is highly likely that chemotherapy contributed to the favorable results.


International Journal of Clinical Oncology | 2004

Reconstruction surgery for patients with musculoskeletal tumor, using a pasteurized autogenous bone graft.

Kenshi Sakayama; Teruki Kidani; Taketsugu Fujibuchi; Junji Kamogawa; Haruyasu Yamamoto; Taihoh Shibata

BackgroundThe pasteurized autogenous bone graft (PABG) is a new method to reuse resected and diseased autogenous bones after heat treatment at a comparatively low temperature (60°C–65°C).MethodsThe subjects of this study were ten patients with musculoskeletal tumor who underwent surgery with a PABG in the 6 years between 1995 and 2000.ResultsThe pasteurized bone developed into bone union in all patients, except for the elderly patients who required repeat surgery. There were no infected patients. The PABG was performed by three different types of reconstruction, a segmental method, an intercalary method, and a combination method with an artificial joint as a spacer. No local recurrence of tumor the pasteurized bone was observed from in any patient.ConclusionThe PABG appears to be a comparatively easy, safe, inexpensive, and effective reconstruction method for musculoskeletal tumors.


Japanese Journal of Cancer Research | 1994

Existence of Lipoprotein Lipase in Human Sarcomas and Carcinomas

Kenshi Sakayama; Hiroshi Masuno; Tatsuhiko Miyazaki; Hideo Okumura; Taihoh Shibata; Hiromichi Okuda

Aqueous extracts of acetone/ether powders of surgically obtained specimens of human tumors hydrolyzed 3H‐labeled triolein in a dose‐dependent manner. The lipolytic activity in these extracts was inhibited by anti‐lipoprotein lipase (LPL) IgG dose‐dependently, 25 μg of anti‐LPL IgG causing 95% inhibition of the activity. Thus, LPL accounts for most of the lipolytic activity in extracts of acetone/ether powders of the tumors. All sarcomas and carcinomas examined contained LPL activity. Western blotting showed that they gave a band corresponding to that of human adipose tissue LPL (Mr=57,000). Immunocytochemical studies showed that LPL was present in cultured human osteosarcoma cells and distributed throughout the cells. We determined the proliferating cell nuclear antigen (PCNA)‐labeling index as an indicator of the proliferative activity of tumor cells and measured LPL activity in extracts of tumors in areas corresponding to those used for determining the PCNA‐labeling index. In malignant fibrous histiocytomas, the PCNA‐labeling index in area a, which corresponds to the subcapsular region, was higher than that in area b, which corresponds to the central region. The LPL activity in area a was 10 times that in area b. In rectal cancer, the index in area c, which corresponds to the subserosal region, was higher than that in area d, which corresponds to the submucosal region. The LPL activity in area c was 1.9 times that in area d. These findings indicate heterogeneity in the distributions of LPL activity within tumors and higher levels of LPL activity in tumors that are proliferating actively.


Journal of Computer Assisted Tomography | 2006

Measurement of tumor blood flow using dynamic contrast-enhanced magnetic resonance imaging and deconvolution analysis : A preliminary study in musculoskeletal tumors

Yoshifumi Sugawara; Kenya Murase; Keiichi Kikuchi; Kenshi Sakayama; Tatsuhiko Miyazaki; Makoto Kajihara; Hitoshi Miki; Teruhito Mochizuki

Objective: To measure tumor blood flow (TBF) using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). Methods: A DCE-MRI was performed using inversion recovery-preparation fast-field echo sequences. Dynamic data were obtained every 3.2 seconds for 2 minutes, immediately after gadolinium injection. In 14 patients with malignant musculoskeletal tumors, TBF maps were generated pixel-by-pixel by deconvolution analysis. For preclinical studies, muscle blood flow in 5 volunteers and signal intensities of different gadolinium concentrations were measured. Results: There was a good linear relationship between signal intensities and gadolinium concentrations (r = 0.989, P < 0.001, at gadolinium concentrations ≤2 mmol/L). The average value of muscle blood flow in volunteers was 11.1 ± 2.7 mL·100 mL−1·min−1. In 14 patients with musculoskeletal tumors, TBF showed wide variances: the lowest of 9.6 mL·100 mL−1·min−1 in liposarcoma and the highest of 182.0 mL·100 mL−1·min−1 in osteosarcoma. After chemotherapy, the TBF values (7.9, 11.0, and 11.7 mL· 100 mL−1·min−1) in the good responders were lower than those (26.8, 31.0, and 62.4 mL·100 mL−1·min−1) in the poor responders. Conclusions: A functional map of TBF generated by DCE-MRI and deconvolution analysis would be a promising tool for evaluating tumor blood flow in vivo.


Radiation Medicine | 2007

Evaluation of tumor blood flow in musculoskeletal lesions: dynamic contrast-enhanced MR imaging and its possibility when monitoring the response to preoperative chemotherapy—work in progress

Makoto Kajihara; Yoshifumi Sugawara; Kenshi Sakayama; Keiichi Kikuchi; Teruhito Mochizuki; Kenya Murase

PurposeThe objective of this study was to calculate tumor blood flow (TBF) in musculoskeletal lesions and to evaluate the usefulness of this parameter in differentiating malignant from benign lesions and monitoring the treatment response to preoperative chemotherapy.Materials and methodsAltogether, 33 patients with musculoskeletal lesions underwent a total of 50 dynamic magnetic resonance imaging (MRI) examinations, including 28 on 9 patients undergoing preoperative chemotherapy. TBF was calculated using deconvolution analysis. Steepest slope (SS) was determined from the time–intensity curve during the first pass of contrast medium.ResultsTBF ranged from 2.7 to 178.6 mL/100 mL/min in benign lesions and from 15.4 to 296.3 mL/100 mL/min in malignant lesions. SS ranged from 0.5%/s to 31.8%/s for benign lesions and from 3.1%/s to 64.8%/sec for malignant lesions. TBF and SS did not differ significantly between benign and malignant lesions. Among the nine patients who underwent preoperative chemotherapy, TBF after chemotherapy was lower in good responders (11.7, 11.0, 7.9 mL/100 mL/min) (n = 3, tumor necrosis ≥90%) than in poor responders (23.4–141.5 mL/100 mL/min) (n = 6, tumor necrosis <90%).ConclusionTBF and SS cannot reliably differentiate malignant from benign lesions. However, they have potential utility in evaluating the preoperative treatment response in patients with malignant musculoskeletal tumors.


Journal of Bone and Joint Surgery-british Volume | 2008

Safety of external fixation during postoperative chemotherapy

Hiroyuki Tsuchiya; Toshiharu Shirai; A. F. Morsy; Kenshi Sakayama; Takuro Wada; K. Kusuzaki; T. Sugita; Katsuro Tomita

We studied the safety of external fixation during post-operative chemotherapy in 28 patients who had undergone distraction osteogenesis (17, group A) or vascularised fibular grafting (11, group B) after resection of a tumour. Four cycles of multi-agent post-operative chemotherapy were administered over a mean period of 14 weeks (6 to 27). The mean duration of external fixation for all patients was 350 days (91 to 828). In total 204 wires and 240 half pins were used. During the period of post-operative chemotherapy, 14 patients (11 in group A, 3 in group B) developed wire- and pin-track infection. A total of ten wires (4.9%) and 11 half pins (4.6%) became infected. Seven of the ten infected wires were in periarticular locations. External fixation during post-operative chemotherapy was used safely and successfully for fixation of a vascularised fibular graft and distraction osteogenesis in 27 of 28 patients. Post-operative chemotherapy for malignant bone tumours did not adversely affect the ability to achieve union or cause hypertrophy of the vascularised fibular graft and had a minimal effect on distraction osteogenesis. Only one patient developed osteomyelitis which required further surgery.


Biochimica et Biophysica Acta | 1992

Glycosylation of lipoprotein lipase in human subcutaneous and omental adipose tissues

Kenshi Sakayama; Hiroshi Masuno; Hideo Okumura; Taiho Shibata; Hiromichi Okuda

Human adipose tissues from the abdomen (subcutaneous), thigh (subcutaneous) and omentum were incubated for 2 h with [35S]methionine. Then glycosylation of lipoprotein lipase (LPL) was analyzed by sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of endoglycosidase H (endo H)-digested subunits of the 35S-labeled lipase. Adipose tissues from the abdomen, thigh, and omentum all synthesized LPL subunits with Mr = 57,000 composed of two types of subunits. One type was partially endo H-sensitive yielding a product with Mr = 55,000, indicating that it had one endo H-resistant and one endo H-sensitive oligosaccharide chain. The other type of subunit was totally endo H-sensitive yielding a product with Mr = 52,000. Subcutaneous adipose tissues contained nearly equal amounts of partially and totally endo H-sensitive subunits of LPL, whereas omental adipose tissues contained mainly partially endo H-sensitive subunits of LPL.


Journal of Orthopaedic Research | 2009

Ketoprofen in topical formulation decreases the matrix metalloproteinase-2 expression and pulmonary metastatic incidence in nude mice with osteosarcoma

Setsuya Kamei; Kenshi Sakayama; Shinta Tamashiro; Junichi Aizawa; Joji Miyawaki; Tatsuhiko Miyazaki; Haruyasu Yamamoto; Yoshiaki Norimatsu; Hiroshi Masuno

The aim of this study was to investigate whether ketoprofen (KP) in topical formulation affected the tumor growth and pulmonary metastasis of LM8 cells, which were inoculated subcutaneously into the back space of male nude mice. At 7 days after inoculation, the tumor was treated topically for 3 weeks with either a KP‐containing patch (KP group) or a placebo‐containing patch (placebo group). The pulmonary metastatic incidence was 100% in the placebo group and 60% in the KP group. The tumor mass of the KP group without pulmonary metastasis, termed the KP/metastasis(−) group, was smaller than that of the placebo group. Immunohistochemical staining for proliferating cell nuclear antigen (PCNA), terminal deoxynucleotidyl transferase‐mediated dUTP nick‐end labeling (TUNEL), matrix metalloproteinase‐2 (MMP‐2), and vascular endothelial growth factor (VEGF) was performed. The tumors of the KP/metastasis(−) group contained fewer PCNA‐positive cells and many more TUNEL‐positive cells in comparison to the placebo group. In the placebo group, MMP‐2 and VEGF were extensively expressed within the tumor, whereas in the KP/metastasis(−) group the expression of these two proteins was very low. In conclusion, the topical treatment of osteosarcoma with KP decreased the expression of MMP‐2 and VEGF, thus resulting in the suppression of tumor growth and pulmonary metastasis.

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Hiroyuki Tsuchiya

Kyoto Pharmaceutical University

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