Vertebral Endplate Cyst Formation in Relation to Properties of Interbody Cages

Manabu Sasaki,Masao Umegaki,Takanori Fukunaga,Yasukazu Hijikata,Yohei Banba,Katsumi Matsumoto,Yasuyoshi Miyao 대한척추신경외과학회 2021 Neurospine Vol.18 No.1

Objective: This retrospective study aimed to compare vertebral endplate cyst formation (VECF), an early predictor for pseudoarthrosis, in different types of interbody cages. Methods: We reviewed 84 cases treated with single-level posterior/transforaminal lumbar interbody fusion. We utilized a polyetheretherketone cage in 20 cases (group P), a titanium cage in 16 cases (group Ti), a titanium-coating polyetheretherketone cage in 13 cases (group TiP) and a porous tantalum cage in 35 cases (group Tn). VECF was evaluated comparing the computed tomography scans taken at day 0 and 6-month postoperation. We defined VECF (+) as enlargement of a pre-existing cyst or de novo formation of a cyst with the diameter over 2 mm. We calculated the adjusted odds ratio (OR) and 95% confidence intervals (CIs) as an indicator of association between different types of cages and VECF using a logistic regression model. Results: VECF was observed in 13 (65%), 7 (44%), 9 (69%), and 8 (23%) cases in groups P, Ti, TiP and Tn, respectively. VECF correlated with the type of cage (p=0.04). In comparison with group P, the proportion of VECF (+) cases was lower in group Tn (OR, 0.16; 95% CI, 0.04–0.60) but not different in group Ti (OR, 0.47; 95% CI, 0.10–2.20) and group TiP (OR, 1.06; 95% CI, 0.21–5.28). No patient underwent additional surgery for the fused spinal level during the follow-up periods (average, 37.9 months; range, 6–76 months). Conclusion: VECF was the least in the porous Tn cage, suggesting its potential superiority for initial stability.

Searching for cosmic missing baryons with DIOS - Diffuse Intergalactic Oxygen Surveyor -

Yasushi Suto,Akihiro Furuzawa,Kazuhisa Mitsuda,Manabu Ishida,Noriko Y. Yamasaki,Ryuichi Fujimoto,Shin Sasaki,Tae Furusho,Takaya Ohashi,Yoshitaka Ishisaki,Yuzuru Tawara 한국물리학회 2004 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.45 No.1

Approximately 30 to 50 percent of the total baryons in the present universe is supposed to take the form of wa arm/hot intergalactic medium (WHIM) whose X-ray continuum emission is very weak. In order to carry out a direct and homogeneous survey of elusive cosmic missing baryons, we propose a dedicated soft-X-ray mission, DIOS (Diffuse Intergalactic Oxygen Surveyor). The unprecedented energy resolution ( 2eV) of the XSA (X-ray Spectrometer Array) on-board DIOS enables us to identify WHIM with gas temperatures T = 106က7K and overdensity = 10က100 located at z < 0:3 through emission lines of Ovii and Oviii. DIOS, which will hopefully be launched in several years time, promises to open a new window of detection and characterization of cosmic missing baryons and to provide yet another important and complementary tool to trace the large-scale structure of the universe.

Pulmonary Metastases After Low-Dose-Rate Brachytherapy for Localized Prostate Cancer

Masahito Kido,Hidetoshi Kuruma,Hiroshi Sasaki,Kenta Miki,Manabu Aoki,Takahiro Kimura,Hiroyuki Takahash,Chihiro Kanehira,Shin Egawa 대한비뇨의학회 2014 Investigative and Clinical Urology Vol.55 No.5

Purpose: To analyze unusual events and focus discussion on pulmonary metastasis in particular after low-dose-rate brachytherapy (LDR-BT) for prostate cancer (PCa). Materials and Methods: A total of 616 consecutive patients who had undergone LDR-BT for clinically localized PCa at Jikei University Hospital between October 2003 and April 2010 were enrolled in this study. Follow-up information was summarized, and patterns of biochemical recurrence and clinical outcome were investigated. Results: Disease risk was stratified as low-risk in 231 patients, intermediate-risk in 365, and high-risk in 20, respectively. Of these patients, 269 (43.7%) had received hormonal therapy (HT) in combination with LDR-BT, and 80 (13.0%) had received external beam radiotherapy (EBRT). Average dosimetric parameter values with and without EBRT were 95.3% and 94.2% for V100, 132.8 Gy and 164.2 Gy for D90, and 180.6 Gy2 and 173.7 Gy2 for the biologically effective dose. Biochemical recurrence was noted in 14 patients (6.1%) in the low-risk group, 25 patients (6.8%) in the intermediate-risk group, and 6 patients (30.0%) in the high-risk group, respectively. In these cases of biochemical recurrence, 9 (64.3%), 13 (52.0%), and 4 patients (66.7%) in each respective risk group showed signs of clinical recurrence. Five patients (19.2%) with clinical recurrence developed pulmonary metastases, of which 4 were isolated lesions. All tumors responded favorably to subsequent HT. Conclusions: LDR-BT for biologically aggressive PCa may be linked to possible pulmonary metastasis owing to tumor dissemination during seed implantation. This information is important in planning adequate treatment for these patients.

TRACING BRIGHT AND DARK SIDES OF THE UNIVERSE WITH X-RAY OBSERVATIONS

SUTO YASUSHI,YOSHIKAWA KOHJI,DOLAG KLAUS,SASAKI SHIN,YAMASAKI NORIKO Y.,OHASHI TAKAYA,MITSUDA KAZUHISA,TAWARA YUZURU,FUJIMOTO RYUICHI,FURUSHO TAE,FURUZAWA AKIHIRO,ISHIDA MANABU,ISHISAKI YOSHITAKA The Korean Astronomical Society 2004 Journal of The Korean Astronomical Society Vol.37 No.5

X-ray observations of galaxy clusters have played an important role in cosmology, especially in determining the cosmological density parameter and the fluctuation amplitude. While they represent the bright side of the universe together with the other probes including the cosmic microwave background and the Type Ia supernovae, the resulting information clearly indicates that the universe is dominated by dark components. Even most of cosmic baryons turns out to be dark. In order to elucidate the nature of dark baryons, we propose a dedicated soft-X-ray mission, DIOS (Diffuse Intergalactic Oxygen Surveyor). Recent numerical simulations suggest that approximately 30 to 50 percent of total baryons at z = 0 take the form of the warm-hot intergalactic medium (WHIM) with $10^5K < T < 10^7K $which has evaded the direct detection so far. The unprecedented energy resolution (${\~} 2eV$) of the XSA (X-ray Spectrometer Array) on-board DIGS enables us to identify WHIM with gas temperature $T = 10^6 {\~} 10^7K$ and overdensity $\delta$ = 10 ${\~}$ 100 located at z < 0.3 through emission lines of OVII and OVIII. In addition, WHIMs surrounding nearby clusters are detectable with a typical exposure time of a day, and thus constitute realistic and promising targets for DIOS.

Bone regeneration within a tailor-made tricalcium phosphate bone implant with both horizontal and vertical cylindrical holes transplanted into the skull of dogs.

Choi, Sung-jin,Lee, Jong-il,Igawa, Kazuyo,Sugimori, Osamaru,Suzuki, Shigeki,Mochizuki, Manabu,Nishimura, Ryouhei,Chung, Ung-il,Sasaki, Nobuo Springer Verlag 2009 Journal of artificial organs Vol.12 No.4

<P>A new tailor-made bone implant (TI) with six horizontal cylindrical holes fabricated from alpha-tricalcium phosphate powder, as described in our previous report, was modified to include five additional vertical holes (TI-v) in an attempt to accelerate the bone regeneration through the holes. This TI-v implant and hydroxyapatite implants (HI) as controls were transplanted into experimental skull defects in dogs. Computed tomography (CT) was performed immediately after the surgery and then every 4 weeks. The dogs were killed for histological analysis at 24 weeks of implantation. On CT, bone bridging between the implant and the skull was observed in the TI-v group from 8 weeks of implantation, whereas a clear bone bridge was not formed in the HI group after 24 weeks of implantation. Histological analysis revealed collagen tissues and new bone formation in the horizontal cylindrical holes in most of the TI-v group, whereas mainly connective tissues invaded the porous structures in the HI group. In the Ti-v group, at the middle of the horizontal holes where they crossed the vertical holes, fibrous collagen tissues and muscular tissue filled up the hole and new bone formation seemed to be blocked. However, in the TI-v group more collagen and bone tissues were formed than in the HI group; when compared with the data in our previous report, however, the total volume of regenerated bone in the horizontal cylindrical holes in the TI-v seemed to be less than that in the TI. Thus, the addition of vertical cylindrical holes in the TI-v was not effective in promoting the faster stabilization of the TI-v in the skull of the dog.</P>

Risk factors for non-reaching of ileal pouch to the anus in laparoscopic restorative proctocolectomy with handsewn anastomosis for ulcerative colitis

Shigenobu Emoto,Keisuke Hata,Hiroaki Nozawa,Kazushige Kawai,Toshiaki Tanaka,Takeshi Nishikawa,Yasutaka Shuno,Kazuhito Sasaki,Manabu Kaneko,Koji Murono,Yuuki Iida,Hiroaki Ishii,Yuichiro Yokoyama,Hiroyu 대한장연구학회 2022 Intestinal Research Vol.20 No.3

Background/Aims: Restorative proctocolectomy (RPC) with ileal pouch-anal anastomosis and handsewn anastomosis for ulcerative colitis requires pulling down of the ileal pouch into the pelvis, which can be technically challenging. We examined risk factors for the pouch not reaching the anus.Methods: Clinical records of 62 consecutive patients who were scheduled to undergo RPC with handsewn anastomosis at the University of Tokyo Hospital during 1989–2019 were reviewed. Risk factors for non-reaching were analyzed in patients in whom hand sewing was abandoned for stapled anastomosis because of nonreaching. Risk factors for non-reaching in laparoscopic RPC were separately analyzed. Anatomical indicators obtained from presurgical computed tomography (CT) were also evaluated.Results: Thirty-seven of 62 cases underwent laparoscopic procedures. In 6 cases (9.7%), handsewn anastomosis was changed to stapled anastomosis because of non-reaching. Male sex and a laparoscopic approach were independent risk factors of non-reaching. Distance between the terminal of the superior mesenteric artery (SMA) ileal branch and the anus > 11 cm was a risk factor for non-reaching.Conclusions: Laparoscopic RPC with handsewn anastomosis may limit extension and induction of the ileal pouch into the anus. Preoperative CT measurement from the terminal SMA to the anus may be useful for predicting non-reaching.

Cranioplasty with Custom-made Artificial Bone after Resection of Multilobular Bone Tumor in a Dog

최성진,Muneki Honnami,I-Li Liu,Kenichi Yamamoto,Shinsuke Ohba,Ryosuke Echigo,Shigeki Suzuki,Ryouhei Nishimura,Ung-il Chung,Nobuo Sasaki,Manabu Mochizuki 한국임상수의학회 2014 한국임상수의학회지 Vol.31 No.1

A 7-year-old spayed female Welsh corgi presented with a mass of the skull. The mass was diagnosed asmultilobular bone tumor and surgically removed. To treat a large bone defect after the tumor removal, custom-madeartificial bone fabricated by a 3-dimensional ink-jet printer was implanted in the defect. Follow-up computed tomographyevaluation was performed for 4.3 years. The implant was well integrated with the skull and had covered the largebone defect during the follow-up period. Gradual degradation of the implant began 6 weeks after surgery. It providesan additional option for the treatment of large bone defect.