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1.
Tohoku J Exp Med ; 261(3): 199-209, 2023 Nov 18.
Article En | MEDLINE | ID: mdl-37704419

A new beta TiNbSn alloy with a low Young's modulus of approximately 40 GPa has been developed to resolve the stress shielding by Young's modulus divergence. In this study, the efficacy of TiNbSn alloy locking plates on bone repair is compared to that of commercially pure titanium (CP-Ti). The TiNbSn alloy and CP-Ti, which have Young's moduli of 49.1 GPa and 107 GPa, respectively, were compared. Male Japanese white rabbits were anesthetized, and osteotomy and osteosynthesis with locking plates were performed on the right tibia. The bone repair was assessed using micro-computed tomography (CT), histomorphometry, immunohistochemistry, and mechanical testing. Micro-CT, histomorphometry, immunohistochemistry, and mechanical testing were performed four weeks after osteotomy. Six weeks after surgery, micro-CT and mechanical testing were performed. Micro-CT analysis at four weeks after surgery showed that the intramedullary fracture callus in the TiNbSn alloy group had more bone volume and numerous bridging structures compared to the CP-Ti group (CP-Ti vs. TiNbSn alloy, 34.3 ± 13.1 mm3 vs. 61.3 ± 19.6 mm3, p = 0.02; mean ± standard deviation). At four weeks post-osteotomy, the healed tibia showed significantly higher strength in the TiNbSn alloy group compared with CP-Ti (CP-Ti vs. TiNbSn alloy, 81.3 ± 31.2 N vs. 133.7 ± 46.6 N, p = 0.04). TiNbSn alloy locking plates had a more positive impact on bone formation and bone strength restoration than the CP-Ti locking plates during the early phase of bone healing.


Fracture Fixation, Internal , Tibia , Male , Animals , Rabbits , Elastic Modulus , Tibia/diagnostic imaging , Tibia/surgery , X-Ray Microtomography , Alloys
2.
SAGE Open Med Case Rep ; 11: 2050313X231177752, 2023.
Article En | MEDLINE | ID: mdl-37325170

We report a successful case of two-stage revision total knee arthroplasty performed for treating painless metallosis after total knee arthroplasty with a metal-backed patella. A 63-year-old woman diagnosed with rheumatoid arthritis underwent left total knee arthroplasty with a metal-backed patella at 32 years of age. The patient did not have knee pain; however, knee joint swelling, a strange noise, and pigmentation were reported 4 years ago. Radiographs showed cloud and metal-line signs anteriorly and posteriorly at the femoral condyle. Therefore, a two-stage surgery was performed for infection prevention and ease of performing posterior synovectomy. The patient underwent initial synovectomy via a posterior approach, followed by anterior synovectomy and revision total knee arthroplasty. Synovectomy was performed well without perioperative infection or failure of wound healing. In cases with metallosis after total knee arthroplasty, the two-stage revision total knee arthroplasty should be considered, depending on the degree of synovial proliferation and the risk of complications.

3.
Clin Orthop Relat Res ; 480(9): 1817-1832, 2022 09 01.
Article En | MEDLINE | ID: mdl-35543573

BACKGROUND: Ti6Al4V alloy, which is commonly used for biomedical applications, has a Young modulus (110 GPa) that is higher than that of human cortical bone (11 to 20 GPa). Using an implant with a material with a low Young modulus that enhances load sharing by the bone even more than those made of Ti6Al4V could be beneficial for bone healing and further reduce the potential for stress shielding. A new ß-type TiNbSn alloy has a low Young modulus of approximately 40 to 49 GPa. However, whether the new titanium alloy with a lower Young modulus is advantageous in terms of fracture healing has not been assessed, and a small-animal model seems a reasonable first step in its assessment. QUESTIONS/PURPOSES: To assess the impact of a TiNbSn alloy plate with a lower Young modulus compared with a Ti6Al4V alloy plate on fracture healing, we evaluated: (1) bony bridging and callus volume, (2) new bone formation and remaining cartilage tissue, (3) osteoblast activity in the callus, and (4) mechanical strength and stiffness of the callus in bending. METHODS: Fracture plates manufactured from TiNbSn and Ti6Al4V alloys, which have Young moduli of 49 GPa and 110 GPa, respectively, were compared. The main reason for using rabbits was the high reliability of the three-point bending mechanical test of the rabbit tibia. Forty-two male Japanese white rabbits weighing 2.8 to 3.4 kg were anesthetized. A 5-cm skin incision was made on the medial side in the mid-diaphysis of the right tibia. Eight-hole plates were used, which were 42 mm long, 5 mm wide, and 1.2 mm thick. Plate fixation was performed using three proximal and three distal screws. After the plate was installed, an osteotomy was performed using a 1-mm-wide wire saw to create a standardized tibial transverse osteotomy model with a 1-mm gap. Bone healing was quantitatively assessed by two nonblinded observers using micro-CT (bony bridging and callus volume), histomorphometry (new bone formation and remaining cartilage tissue), immunohistochemistry (osteoblast activity), and mechanical testing (mechanical strength and stiffness in bending). Measurements on nondemineralized specimens were descriptive statistics due to their small number. Four weeks after osteotomy and fixation, 30 rabbits were euthanized to undergo micro-CT and subsequent mechanical testing (n = 12), histomorphometry and immunohistochemistry with demineralized specimens (n = 12), and histomorphometry with a nondemineralized specimen (n = 6). Eight weeks postoperatively, 12 rabbits were euthanized for micro-CT and subsequent mechanical testing. RESULTS: Intramedullary fracture calluses treated with TiNbSn alloy plates had larger bone volumes and more numerous bridging structures than those treated with Ti6Al4V alloy plates at 4 weeks after osteotomy (Ti6Al4V alloy versus TiNbSn alloy: 30 ± 7 mm 3 versus 52 ± 14 mm 3 , mean difference 22 [95% CI 9 to 37]; p = 0.005; ICC 0.98 [95% CI 0.95 to 0.99]). Histologic assessments demonstrated there was greater new bone formation (total callus: Ti6Al4V versus TiNbSn: 16 ± 4 mm 2 versus 24 ± 7 mm 2 , mean difference 8 [95% CI 1 to 16]; p = 0.04; ICC 0.98 [95% CI 0.93 to 0.99]; intramedullary callus: Ti6Al4V versus TiNbSn: 6 ± 4 mm 2 versus 13 ± 5 mm 2 , mean difference 7 [95% CI 1 to 13]; p = 0.02; ICC 0.98 [95% CI 0.95 to 0.99]) and a higher number of osteocalcin-positive cells (Ti6Al4V alloy versus TiNbSn alloy: 1397 ± 197 cells/mm 2 versus 2044 ± 183 cells/mm 2 , mean difference 647 [95% CI 402 to 892]; p < 0.001; ICC 0.98 [95% CI 0.95 to 0.99]) in the TiNbSn alloy group than in the Ti6Al4V alloy group. At 4 weeks after osteotomy, both bone strength and stiffness of the healed bone in the TiNbSn alloy group were higher than those in the Ti6Al4V alloy group (maximum load: Ti6Al4V alloy versus TiNbSn alloy: 83 ± 30 N versus 127 ± 26 N; mean difference 44 [95% CI 8 to 80]; p = 0.02; stiffness: Ti6Al4V alloy versus TiNbSn alloy: 92 ± 43 N/mm versus 165 ± 63 N/mm; mean difference 73 [95% CI 4 to 143]; p = 0.047). Eight weeks after osteotomy, no between-group differences were observed in the strength and stiffness of the healed bone. CONCLUSION: The results of this study indicate that TiNbSn alloy plate with a lower Young modulus resulted in improved bone formation and stiffer callus during the early phase (4 weeks after surgery) but not the later phase (8 weeks after surgery) of bone healing. CLINICAL RELEVANCE: An overly stiff plate may impair callus formation and bone healing. The TiNbSn alloy plate with a low Young modulus improves the early formation of new bone and stiff callus at the osteotomy site compared with the Ti6Al4V alloy plate in the healing process, which may promote bone repair. TiNbSn alloy may be a promising biomaterial for fracture treatment devices. Further research to address concerns about the strength of TiNbSn alloy plates, such as fatigue life and plate fracture, will be necessary for clinical applications, including mechanical tests to verify fatigue life and validation in larger animals with greater body weight.


Bone Plates , Tibia , Alloys/chemistry , Animals , Biomechanical Phenomena , Elastic Modulus , Fracture Healing , Humans , Male , Rabbits , Reproducibility of Results , Tibia/surgery
4.
Rev Sci Instrum ; 93(4): 043711, 2022 Apr 01.
Article En | MEDLINE | ID: mdl-35489903

We report the design and performance of a cryogen-free, pulse-tube refrigerator (PTR)-based scanning probe microscopy (SPM) system capable of operating at a base temperature of near 5 K. We achieve this by combining a home-made interface design between the PTR cold head and the SPM head, with an automatic gas-handling system. The interface design isolates the PTR vibrations by a combination of polytetrafluoroethylene and stainless-steel bellows and by placing the SPM head on a passive vibration isolation table via two cold stages that are connected to thermal radiation shields using copper heat links. The gas-handling system regulates the helium heat-exchange gas pressures, facilitating both the cooldown to and maintenance of the base temperature. We discuss the effects of each component using measured vibration, current-noise, temperature, and pressure data. We demonstrate that our SPM system performance is comparable to known liquid-helium-based systems with the measurements of the superconducting gap spectrum of Pb, atomic-resolution scanning tunneling microscopy image and quasiparticle interference pattern of Au(111) surface, and non-contact atomic force microscopy image of NaCl(100) surface. Without the need for cryogen refills, the present SPM system enables uninterrupted low-temperature measurements.

5.
Surg Case Rep ; 5(1): 150, 2019 Oct 22.
Article En | MEDLINE | ID: mdl-31641880

BACKGROUND: Calcifying fibrous tumor (CFT) is a rare benign soft tissue lesion. CASE PRESENTATION: A 30-year-old woman was admitted to our hospital with complaints of epigastralgia. A 15-mm submucosal tumor was identified in the greater curvature of the superior body of the stomach by upper gastrointestinal endoscopy. Endoscopic ultrasonography revealed a hypoechoic lesion with an acoustic shadow consistent with calcification. Computed tomography showed a gastric tumor with calcification. A gastrointestinal stromal tumor was diagnosed, and gastric wedge resection was performed by laparoscopy and endoscopy cooperative surgery. On pathological examination, the tumor was identified to be a CFT. Postoperative serum IgG4 levels were 26.0 mg/dl, which supported the diagnosis of probable immunoglobulin G (IgG) 4-related disease, according to the comprehensive diagnostic criteria of IgG4-related disease. The patient was discharged on postoperative day 7 and remains well with no evidence of tumor recurrence for 2 years after resection. CONCLUSION: We herein reported a patient with a gastric CFT suspected to be complicated with immunoglobulin G4-related disease that was successfully treated by laparoscopy and endoscopy cooperative surgery.

6.
Sci Rep ; 5: 14808, 2015 Oct 07.
Article En | MEDLINE | ID: mdl-26443124

Transition-metal dichalcogenide layered materials, consisting of a transition-metal atomic layer sandwiched by two chalcogen atomic layers, have been attracting considerable attention because of their desirable physical properties for semiconductor devices, and a wide variety of pn junctions, which are essential building blocks for electronic and optoelectronic devices, have been realized using these atomically thin structures. Engineering the electronic/optical properties of semiconductors by using such heterojunctions has been a central concept in semiconductor science and technology. Here, we report the first scanning tunneling microscopy/spectroscopy (STM/STS) study on the electronic structures of a monolayer WS2/Mo1-xWxS2 heterojunction that provides a tunable band alignment. The atomically modulated spatial variation in such electronic structures, i.e., a microscopic basis for the band structure of a WS2/Mo1-xWxS2 heterojunction, was directly observed. The macroscopic band structure of Mo1-xWxS2 alloy was well reproduced by the STS spectra averaged over the surface. An electric field of as high as 80 × 10(6) Vm(-1) was observed at the interface for the alloy with x = 0.3, verifying the efficient separation of photoexcited carriers at the interface.

7.
Data Brief ; 5: 642-5, 2015 Dec.
Article En | MEDLINE | ID: mdl-26958620

This data article contains a supplementary figure and validation data relating to the research article entitled "Genotyping of wild-type cytochrome P450 2A6 and whole-gene deletion using human blood samples and a multiplex real-time polymerase chain reaction method with dual-labeled probes" (Shimizu et al., Clinica Chimica Acta 441, 71-74, 2015), which presents a multiplex real-time polymerase chain reaction method with dual-labeled probes for human P450 2A6 wild-type and whole-gene deletion. Real-time methods have dramatically improved the speed of complex genetic diagnostics compared to conventional assays based on restriction enzyme digestion. Here, we show the basic assay validation data by single and multiplex determinations in comparison with commercial TaqMan copy number assays for P450 2A6.

8.
Virchows Arch ; 462(5): 533-40, 2013 May.
Article En | MEDLINE | ID: mdl-23536281

The morphogenesis of lobular restructuring to liver cirrhosis in nonalcoholic steatohepatitis (NASH) is yet to be clearly understood. Therefore, we observed tissue samples from three biopsies and one autopsy with NASH in the non-cirrhotic stage three-dimensionally to elucidate the evolution of fibrosis and the changes of angioarchitecture. Histologic reconstructions revealed that pericellular fibrosis developed around the central vein in the early stage and gradually progressed to arch-shaped band-like fibrosis connecting the central veins in the neighboring lobules. In contrast, the basic angioarchitecture of the portal vein in the portal tracts tended to be preserved in the non-cirrhotic stage, although the portal vein architecture was slightly altered as the portal tract underwent gradual fibrous expansion. In addition, a striking development of arteries originating from the portal tract was found in the fibrotic area around the central and sublobular veins. In summary, while central-central bridging fibrosis and ectopic arterial development were conspicuous, the lobular architecture was maintained relatively well in the non-cirrhotic stage of NASH because of only mildly damaged angioarchitecture of the portal veins. The process of lobular restructuring in NASH is considered to be different from that in chronic viral hepatitis in the non-cirrhotic stage.


Fatty Liver/pathology , Liver/pathology , Portal Vein/pathology , Adult , Female , Humans , Image Interpretation, Computer-Assisted , Male , Middle Aged
9.
Hepatogastroenterology ; 59(117): 1478-9, 2012.
Article En | MEDLINE | ID: mdl-22683965

BACKGROUND/AIMS: Although proximal gastrectomy has become a procedure of choice for patients' early cancer in the upper third of stomach, no clinical guide for optimal gastric resection in order to avoid postoperative jejunal ulcer is available. The aim of this study was to investigate whether determining the distribution of parietal and chief cells of the stomach using Congo red test is clinically relevant. METHODOLOGY: The F-line was defined as a boundary line between fundic and intermediate area of the stomach according to the pathological findings in 29 patients who underwent total gastrectomy for early gastric cancer, whereas the f-line was regarded as a boundary line between intermediate and pyloric area. In the additional 6 patients undergoing vagus-preserving proximal gastrectomy with jejunal pouch interposition, endoscopic Congo red test was preoperatively performed to determine the F-f-line. RESULTS: The distances from the pyloric ring to f-line on the lesser and greater curvatures were variable. Long-term outcomes of proximal gastrectomy guided by preoperative endoscopic Congo red test were favorable. CONCLUSIONS: It is suggested that preoperative endoscopic Congo red test is useful to determine the appropriate cutting line in order to avoid postoperative jejunal ulcer after proximal gastrectomy.


Gastrectomy/adverse effects , Gastrectomy/methods , Jejunal Diseases/etiology , Stomach Neoplasms/surgery , Ulcer/etiology , Chief Cells, Gastric/cytology , Coloring Agents , Congo Red , Gastroscopy , Humans , Jejunal Diseases/prevention & control , Parietal Cells, Gastric/cytology , Preoperative Care , Ulcer/prevention & control
10.
Chemotherapy ; 53(5): 378-82, 2007.
Article En | MEDLINE | ID: mdl-17785974

We report 2 cases of advanced gastric cancer with synchronous liver metastases who were successfully downstaged using S-1 plus low-dose cisplatin chemotherapy followed by surgical resection. S-1 was administered orally (80 mg/m(2)/day) twice daily for 14 consecutive days, and cisplatin (15 mg/m(2)) was infused over 1 h on days 1 and 8. Successful downstaging of the hepatic metastases was confirmed by imaging analyses; however, neither patient showed a complete response of the primary lesion in the stomach. Toxicities, according to the WHO criteria, were mild. The patients underwent surgical resection within 4 weeks after the last chemotherapy. Postoperatively, they were discharged without complications and received adjuvant chemotherapy. Both patients remained alive and well at 17 and 12 months after surgery, respectively, without recurrence. These cases provide further evidence that S-1 plus low-dose cisplatin chemotherapy enables downstaging of advanced gastric cancer and a subsequent potentially curative resection without serious complications.


Cisplatin/therapeutic use , Liver Neoplasms/drug therapy , Liver Neoplasms/pathology , Oxonic Acid/therapeutic use , Preoperative Care , Stomach Neoplasms/drug therapy , Stomach Neoplasms/pathology , Tegafur/therapeutic use , Drug Combinations , Drug Therapy, Combination , Humans , Liver Neoplasms/secondary , Liver Neoplasms/surgery , Male , Middle Aged , Stomach Neoplasms/surgery , Tomography Scanners, X-Ray Computed
11.
Lasers Surg Med ; 39(1): 76-82, 2007 Jan.
Article En | MEDLINE | ID: mdl-17096413

BACKGROUND AND OBJECTIVE: We developed a new imaging system to detect sentinel nodes (SNs) using a novel fluorescent tracer, ATX-S10Na(II), and investigated its usefulness in an animal model. STUDY DESIGN/MATERIALS AND METHODS: Human gastric carcinoma cells were implanted orthotopically into nude rats. ATX-S10Na(II) was injected subserosally into the primary tumor lesion, and visualized by a fluorescence spectro-laparoscope. Presence of tumor cells in lymph nodes (LNs) was determined by RT-PCR specific for human beta-actin. RESULTS: Injection of ATX-S10Na(II) was successful in 27 tumor-bearing rats. A red fluorescence was incorporated into the left gastric and hepatic LNs in 25 and 2 rats, respectively. Of note, human beta-actin was detected in most of these LNs. Fluorescence was not detected in LNs that did not contain cancer. CONCLUSION: ATX-S10Na(II) is useful for the detection of cancer-containing SNs in an animal model of gastric carcinoma, and may serve as a novel tracer in SN navigation surgery.


Fluorescent Dyes , Lymphatic Metastasis/diagnosis , Porphyrins , Spectrometry, Fluorescence , Stomach Neoplasms/pathology , Actins/metabolism , Animals , CA-19-9 Antigen/blood , Cell Line, Tumor , Disease Models, Animal , Female , Humans , Neoplasm Staging , Neoplasm Transplantation , Rats , Rats, Inbred F344 , Rats, Nude , Reverse Transcriptase Polymerase Chain Reaction , Sentinel Lymph Node Biopsy
12.
Gastric Cancer ; 9(3): 235-9, 2006.
Article En | MEDLINE | ID: mdl-16952044

A 57-year-old man with gastrointestinal stromal tumor (GIST) of the stomach with peritoneal dissemination underwent gastrectomy. After surgery, he was treated with 400 mg/day of imatinib, without recurrence, for 26 months. At 26 months, the imatinib dose was reduced because of nausea, and 4 months after the dose reduction, recurrence of GIST was detected, for which surgical resection was performed again. The first surgical specimen had a mutation of exon 11 in the c-kit receptor gene. Intriguingly, the second surgical specimen had a novel mutation of exon 17, in addition to the above-mentioned mutation, in the c-kit receptor gene. Based on the result of molecular analysis, the novel mutation of exon 17, induced by longterm chemotherapy, was judged to have been responsible for the recurrence, which perhaps was triggered by the dose reduction of imatinib.


Gastrointestinal Stromal Tumors/drug therapy , Gastrointestinal Stromal Tumors/genetics , Neoplasm Recurrence, Local/chemically induced , Piperazines/adverse effects , Piperazines/therapeutic use , Point Mutation , Proto-Oncogene Proteins c-kit/genetics , Pyrimidines/adverse effects , Pyrimidines/therapeutic use , Antineoplastic Agents/adverse effects , Antineoplastic Agents/therapeutic use , Base Sequence , Benzamides , Drug Resistance, Neoplasm/genetics , Gastrointestinal Stromal Tumors/pathology , Humans , Imatinib Mesylate , Male , Middle Aged , Molecular Sequence Data , Neoplasm Recurrence, Local/surgery
13.
Nihon Ishinkin Gakkai Zasshi ; 44(2): 71-5, 2003.
Article Ja | MEDLINE | ID: mdl-12748586

Antigenic components extracted by treatment with beta-mercaptoethanol from M. furfur, M. globosa, M. restricta, M. slooffiae, and M. sympodialis were studied for immunoglobulin E antibodies in sera of patients with atopic dermatitis. CBB staining and lectin blots of the extracts showed that each Malassezia species contained species-dependent components at the protein level. In a Western blot with the 2-ME extracts,IgE antibodies against the Malassezia species were found in sera of 83% (for M. globosa), 74% (for M. sympodialis), 65% (for M. furfur), 56% (for M. restricta) and 50% (for M. slooffiae) of the AD patients. In the Western blot inhibition test, the 2-ME extract of M. globosa partially inhibited the reaction of the antigenic components of other Malassezia species with the patients IgE antibodies. These results indicated that Malassezia species contained both species-specific and common antigenic components at the IgE antibody level. A major component of M. globosa was isolated from the 2-ME extract of this fungus by ion-exchange column chromatography and was referred to as Malg46b. Dot blot with the Malg46b containing fraction immunologically reacted with 69% of the sera of the patients, and with 83% of the sera of those who were positive for IgE antibodies to the 2-ME extract of M. globosa in Western blot. The intensities generated for each dot correlated well with the total intensities generated for the 2-ME extract of M. globosa in Western blot (r=0.763) The polyclonal antibody to Malg46b reacted strongly only with the 2-ME extract of M. globosa and reacted slightly with M. restricta. These results indicate that a glycoprotein, Malg46b of M. globosa, is dominantly expressed in this fungus and is a possible major antigen for IgE antibodies in patients with AD.


Antibodies, Fungal/blood , Dermatitis, Atopic/immunology , Dermatomycoses/immunology , Immunoglobulin E/blood , Malassezia/immunology , Antigens, Fungal/analysis , Humans , Malassezia/classification
14.
J Dermatol Sci ; 29(3): 166-70, 2002 Sep.
Article En | MEDLINE | ID: mdl-12234705

In the present study, the abilities of major Malassezia species, M. sympodialis, M. globosa and M. furfur, to assimilate topical agents, which have been widely used as a material of ointment for skin diseases, were tested. Obvious growth of M. furfur on GYEP agar plate was noted in the presence of white petrolatum, purified white petrolatum, hydrophilic ointment and heparinoid in hydrophilic ointment, and also M. sympodialis showed similar growth when they were cultured with hydrophilic or heparinoid in hydrophilic ointment. In contrast, M. globosa did not grow on GYEP in the presence of the any topical agents tested. These results suggest that Malassezia species, especially M. furfur and M. sympodialis, assimilate several topical agents and showed the drug-depended cell growth.


Fats/pharmacology , Malassezia/drug effects , Malassezia/growth & development , Pharmaceutical Vehicles/administration & dosage , Administration, Topical , Colony Count, Microbial , Malassezia/genetics , Malassezia/physiology , Ointments , Pharmaceutical Vehicles/pharmacology , Solubility , Species Specificity
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