鏡視下足関節固定術で使用される中空海綿骨螺子による圧着圧の比較

Background: When performing arthroscopic ankle arthrodesis for end-stage ankle arthritis, internal fixation is performed using bone screws after appropriate preparation. However, optimal characteristics of bone screws have not been examined in terms of pressure force. Objective comparisons of bone-screw performance may provide information on procedures for arthroscopic ankle arthrodesis. The study objectives were to determine whether it was possible to measure compressive force changes using the newly developed device and to infer all screw characteristics from measurement results when used in actual surgeries. In addition, we performed experiments on cadavers to verify whether the experimental results could be applied to the joints of living subjects. Methods: Three types of screws (S1, S2, and S3) were inserted into the unique measurement device, and the changes in pressure were measured for each 45° turn. Changes in pressure and maximum pressure force were recorded after the application of the screws. After reaching the maximum pressure in the simulated bone, further screw rotations were accompanied by a gradual pressure decrease to 0 MPa. We also measured pressure changes in a similar manner by inserting a miniature pressure sensor into the talocrural joints of cadavers. Results: The mean maximum pressure ± standard deviation for S1, S2, and S3 were 0.832 ± 0.164 MPa, 0.434 ± 0.116 MPa, and 0.414 ± 0.127 MPa, respectively. Pressure slopes to the maximum did not significantly differ between the screws in the simulated bone, and a subsequent pressure decrease to 0 MPa was significantly more rapid for S1 than for S2 and S3. Although pressure failure after the overtightening of screws was only observed in the simulated bone, patterns of pressure vs. rotation angle were similar in simulated and cadaveric bones. The pressure profile characteristics of three different screw types were determined. Conclusions: We were able to measure the compressive force changes using the newly developed device when the screws were inserted. On the basis of the measurement results, we were able to infer the characteristics of all screws when used in actual surgery.博士（医学）・乙第1403号・平成29年6月28日Copyright © The Author(s). 2017 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated

The tumor-forming type of multiple myeloma. I. Biological behavior.

A total of 45 cases of multiple myeloma has been followed up clinically during the period from 7 to 80 months. Out of these, six patients (13.3%) were diagnosed to be the tumor-forming type; they developed discrete tumor formation at the disease onset or during clinical observation. Biological behavior of these cases is briefly outlined. Histologically, five cases presented with well or moderately well differentiated plasma cells according to the grading made by Pasmantier and Azar. The remaining one case was poorly differentiated in cell maturity, and with electron and immunofluorescence microscopies, proved to be of plasmacytic nature.</p

アキレス腱付着部症に対しアキレス腱モーメントアーム長が及ぼす影響

Insertional Achilles tendinopathy (IAT) is caused by traction force of the tendon. The effectiveness of the suture bridge technique in correcting it is unknown. We examined the moment arm in patients with IAT before and after surgery using the suture bridge technique, in comparison to that of healthy individuals. We hypothesized that the suture bridge method influences the moment arm length. An IAT group comprising 10 feet belonging to 8 patients requiring surgical treatment for IAT were followed up postoperatively and compared with a control group comprising 15 feet of 15 healthy individuals with no ankle complaints or history of trauma or surgery. The ratio of the moment arm (MA) length/foot length was found to be statistically significant between the control group, the IAT group preoperatively and the IAT group postoperatively (p < 0.01). Despite no significant difference in the force between the control and preoperative IAT groups, a significantly higher force to the Achilles tendon was observed in the IAT group postoperatively compared to the other groups (p < 0.05). This study demonstrates that a long moment arm may be one of the causes of IAT, and the suture bridge technique may reduce the Achilles tendon moment arm.博士（医学）・甲第845号・令和4年9月28日© 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/)

大学サッカー選手における第5中足骨疲労骨折の発生因子

BACKGROUND: The pathogenesis of fifth metatarsal stress fractures remains uncertain. HYPOTHESIS: Physical characteristics and environmental factors, which have received limited attention in the literature thus far, might be involved in the development of fifth metatarsal stress fractures. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: To test the study hypothesis, a medical examination and survey of the living environment of collegiate soccer players was conducted and correlated with the existence of fifth metatarsal stress fractures. The survey and measurements were conducted in 273 male athletes from the same college soccer team between 2005 and 2013. A medical examination comprising assessment of stature, body weight, body mass index, foot-arch height ratio, toe-grip strength, quadriceps angle, leg-heel angle, functional reach test, single-leg standing time with eyes closed, straight-leg raise angle, finger-floor distance, heel-buttock distance, ankle joint range of motion, and a general joint laxity test were performed once a year, along with a questionnaire survey. The survey was also repeated when a fifth metatarsal stress fracture was diagnosed. The study participants were separated into a fifth metatarsal stress fracture injury group and a noninjury group. The measurement items and survey items were compared, and the association between the factors and the presence or absence of injuries was analyzed. RESULTS: Toe-grip strength was significantly weaker in the injury group compared with the noninjury group, suggesting that weak toe-grip is associated with fifth metatarsal stress fracture (P < .05). In addition, fifth metatarsal stress fractures were more common in the nondominant leg (P < .05). Between-group comparisons of the other items showed no statistically significant differences. CONCLUSION: The association between weak toe-grip strength and fifth metatarsal fracture suggests that weak toe-grip may lead to an increase in the load applied onto the lateral side of the foot, resulting in stress fracture. The finding of stress fracture being more common in the nondominant leg needs further study.博士（医学）・甲第660号・平成28年11月24日© The Author(s) 2015 : This open-access article is published and distributed under the Creative Commons Attribution - NonCommercial - No Derivatives License (http://creativecommons.org/ licenses/by-nc-nd/3.0/), which permits the noncommercial use, distribution, and reproduction of the article in any medium, provided the original author and source are credited. You may not alter, transform, or build upon this article without the permission of the Author(s). For reprints and permission queries, please visit SAGE’s Web site at http://www.sagepub.com/journalsPermissions.nav

大腿骨頭靭帯の組織学的および分子学的特性に関する研究

The ligamentum capitis femoris (LCF) has increased in clinical significance through the development of hip arthroscopy. The histological pathologies and molecular composition of the femoral attachment of the LCF and the degeneration caused by LCF disruption were investigated in the human hip joint. Twenty-four LCFs were retrieved at surgery for femoral neck fracture (age range: 63–87 years). In the “intact” (i.e., intact throughout its length, n = 12) group, the attachment consisted of rich fibrocartilage. Fibrocartilage cells were present in the midsubstance. In contrast, the construction of the attachment in the “disrupted” (i.e., ligament no longer attached to the femoral head, n = 12) group had disappeared. The attachment in the disrupted group was not labeled for type II collagen or aggrecan, while that in the intact group was labeled for types I, II and III collagen, chondroitin 4-sulfate, chondroitin 6-sulfate, aggrecan, and versican. The percentage of single-stranded DNA-positive chondrocytes was significantly higher in the disrupted group than in the intact group. We conclude that the femoral attachment of the LCF has a characteristic fibrocartilaginous structure that is likely to adjust to the mechanical load, and suggest that its degeneration is advanced by disruption and should be regarded as a clinical pathology.博士（医学）・乙第1353号・平成27年3月16日© 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd

足関節運動とアキレス腱の緊張がアキレス腱と踵骨間の接触圧に与える影響

Impingement between the Achilles tendon and the posterosuperior prominence of the calcaneus is considered to be a cause of insertional Achilles tendinopathy. The corresponding treatment intends to reduce tensile stress from calf muscles and avoid hyper-dorsiflexion of the ankle joint for decreasing the contact pressure; however, no study has reported on whether these treatments can decrease impingement. Thus, this study investigated the hypothesis that the tensile stress of the Achilles tendon and ankle motion affect the contact pressure between the Achilles tendon and the posterosuperior prominence of the calcaneus. Six fresh-frozen cadaveric lower leg specimens were procured. Each specimen was set to a custom foot-loading frame and loaded with a ground reaction force of 40 N and a tensile load of 70 N along the Achilles tendon. The contact pressure between the Achilles tendon and the posterosuperior prominence of the calcaneus was measured using a miniature pressure sensor under different tensile loadings of the Achilles tendon at the neutral ankle position. Similarly, the contact pressures during the ankle motion from a neutral position to maximum dorsiflexion were measured. The tensile load of the Achilles tendon and ankle motion affected the contact pressure between the Achilles tendon and the posterosuperior prominence of the calcaneus. The contact pressure increased with tensile load or ankle dorsiflexion. Conditions with increasing the tensile load of the Achilles tendon or under ankle dorsiflexion increase the contact pressure between the Achilles tendon and the posterosuperior prominence of the calcaneus.博士（医学）・甲第806号・令和3年12月21日Copyright © 2021 the American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved

Antibacterial and cytotoxic effects of photoexcited Au clusters via blue high-power or white low-power light emitting diode irradiation

The development of photosensitizers and light sources has enabled the use of antimicrobial photodynamic therapy (aPDT) in various dental therapies. In the present study, we compared the antibacterial and cytotoxic effects of Au clusters photoexcited by blue and white LED irradiation. We fabricated novel photosensitizers, captopril-protected gold (Capt-Au) clusters and lysozyme-stabilized gold (Lyz-Au) clusters, for aPDT. Au clusters were then photoexcited by two kinds of light sources, blue high-power and white low-power light-emitting diodes (LEDs). Since white LED contains a wide spectrum of light (400–750 nm), white LED would be relevant for aPDT even if using a low-power source. The turbidity and viability of Streptococcus mutans were assessed following application of Capt-Au clusters (500 μg/mL) or Lyz-Au clusters (1,000 μg/mL) photoexcited by a blue high-power LED (1,000 mW/cm2) or white low-power LED (80 mW/cm2). In addition, the cytotoxicity of Au clusters and LED irradiation was evaluated in NIH3T3 and MC3T3-E1 cells. Au clusters photoexcited by the white low-power LED equally decreased the turbidity and viability of S. mutans compared with blue high-power LED. However, Au clusters photoexcited by white LED irradiation caused decreased cytotoxicity in mammalian cells compared with those photoexcited by blue LED irradiation. In conclusion, white LEDs possess biosafe properties for aPDT using Au clusters

TRPC6 regulates phenotypic switching of vascular smooth muscle cells through plasma membrane potential-dependent coupling with PTEN

Vascular smooth muscle cells (VSMCs) play critical roles in the stability and tonic regulation of vascular homeostasis. VSMCs can switch back and forth between highly proliferative synthetic and fully differentiated contractile phenotypes in response to changes in the vessel environment. Although abnormal phenotypic switching of VSMCs is a hallmark of vascular disorders such as atherosclerosis and restenosis after angioplasty, how control of VSMC phenotypic switching is dysregulated in pathologic conditions remains obscure. We found that inhibition of canonical transient receptor potential 6 (TRPC6) channels facilitated contractile differentiation of VSMCs through plasma membrane hyperpolarization. TRPC6-deficient VSMCs exhibited more polarized resting membrane potentials and higher protein kinase B (Akt) activity than wild-type VSMCs in response to TGF-β1 stimulation. Ischemic stress elicited by oxygen-glucose deprivation suppressed TGF-β1-induced hyperpolarization and VSMC differentiation, but this effect was abolished by TRPC6 deletion. TRPC6-mediated Ca2+ influx and depolarization coordinately promoted the interaction of TRPC6 with lipid phosphatase and tensin homolog deleted from chromosome 10 (PTEN), a negative regulator of Akt activation. Given the marked up-regulation of TRPC6 observed in vascular disorders, our findings suggest that attenuation of TRPC6 channel activity in pathologic VSMCs could be a rational strategy to maintain vascular quality control by fine-tuning of VSMC phenotypic switching.Fil: Numaga-Tomita, Takuro. No especifíca;Fil: Shimauchi, Tsukasa. Kyushu University; JapónFil: Oda, Sayaka. No especifíca;Fil: Tanaka, Tomohiro. No especifíca;Fil: Nishiyama, Kazuhiro. Kyushu University; JapónFil: Nishimura, Akiyuki. Kyushu University; JapónFil: Birnbaumer, Lutz. Pontificia Universidad Católica Argentina "Santa María de los Buenos Aires". Instituto de Investigaciones Biomédicas. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas; ArgentinaFil: Mori, Yasuo. No especifíca;Fil: Nishida, Motohiro. Kyushu University; Japó

imary testicular plasmacytoma: a case report.

&#60;P&#62;A 73-year-old man with a left testicular tumor is presented. Orchiectomy was performed and the tumor was diagnosed as a plasmacytoma. There has been no bone lesion or immunoglobulin abnormality during a follow-up period more than one year. For several reasons, the tumor was regarded as a primary plasmacytoma of the testicle. The literature concerning testicular plasmacytoma is reviewed briefly.</p