Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 265
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Nature ; 613(7944): 490-495, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36653566

RESUMO

The tunnelling electric current passing through a magnetic tunnel junction (MTJ) is strongly dependent on the relative orientation of magnetizations in ferromagnetic electrodes sandwiching an insulating barrier, rendering efficient readout of spintronics devices1-5. Thus, tunnelling magnetoresistance (TMR) is considered to be proportional to spin polarization at the interface1 and, to date, has been studied primarily in ferromagnets. Here we report observation of TMR in an all-antiferromagnetic tunnel junction consisting of Mn3Sn/MgO/Mn3Sn (ref. 6). We measured a TMR ratio of around 2% at room temperature, which arises between the parallel and antiparallel configurations of the cluster magnetic octupoles in the chiral antiferromagnetic state. Moreover, we carried out measurements using a Fe/MgO/Mn3Sn MTJ and show that the sign and direction of anisotropic longitudinal spin-polarized current in the antiferromagnet7 can be controlled by octupole direction. Strikingly, the TMR ratio (about 2%) of the all-antiferromagnetic MTJ is much larger than that estimated using the observed spin polarization. Theoretically, we found that the chiral antiferromagnetic MTJ may produce a substantially large TMR ratio as a result of the time-reversal, symmetry-breaking polarization characteristic of cluster magnetic octupoles. Our work lays the foundation for the development of ultrafast and efficient spintronic devices using antiferromagnets8-10.

2.
Nature ; 607(7919): 474-479, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35859198

RESUMO

Electrical control of a magnetic state of matter lays the foundation for information technologies and for understanding of spintronic phenomena. Spin-orbit torque provides an efficient mechanism for the electrical manipulation of magnetic orders1-11. In particular, spin-orbit torque switching of perpendicular magnetization in nanoscale ferromagnetic bits has enabled the development of stable, reliable and low-power memories and computation12-14. Likewise, for antiferromagnetic spintronics, electrical bidirectional switching of an antiferromagnetic order in a perpendicular geometry may have huge impacts, given its potential advantage for high-density integration and ultrafast operation15,16. Here we report the experimental realization of perpendicular and full spin-orbit torque switching of an antiferromagnetic binary state. We use the chiral antiferromagnet Mn3Sn (ref. 17), which exhibits the magnetization-free anomalous Hall effect owing to a ferroic order of a cluster magnetic octupole hosted in its chiral antiferromagnetic state18. We fabricate heavy-metal/Mn3Sn heterostructures by molecular beam epitaxy and introduce perpendicular magnetic anisotropy of the octupole using an epitaxial in-plane tensile strain. By using the anomalous Hall effect as the readout, we demonstrate 100 per cent switching of the perpendicular octupole polarization in a 30-nanometre-thick Mn3Sn film with a small critical current density of less than 15 megaamperes per square centimetre. Our theory reveals that the perpendicular geometry between the polarization directions of current-induced spin accumulation and of the octupole persistently maximizes the spin-orbit torque efficiency during the deterministic bidirectional switching process. Our work provides a significant basis for antiferromagnetic spintronics.

3.
Nature ; 580(7805): 608-613, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32350469

RESUMO

Electrical manipulation of phenomena generated by nontrivial band topology is essential for the development of next-generation technology using topological protection. A Weyl semimetal is a three-dimensional gapless system that hosts Weyl fermions as low-energy quasiparticles1-4. It has various exotic properties, such as a large anomalous Hall effect (AHE) and chiral anomaly, which are robust owing to the topologically protected Weyl nodes1-16. To manipulate such phenomena, a magnetic version of Weyl semimetals would be useful for controlling the locations of Weyl nodes in the Brillouin zone. Moreover, electrical manipulation of antiferromagnetic Weyl metals would facilitate the use of antiferromagnetic spintronics to realize high-density devices with ultrafast operation17,18. However, electrical control of a Weyl metal has not yet been reported. Here we demonstrate the electrical switching of a topological antiferromagnetic state and its detection by the AHE at room temperature in a polycrystalline thin film19 of the antiferromagnetic Weyl metal Mn3Sn9,10,12,20, which exhibits zero-field AHE. Using bilayer devices composed of Mn3Sn and nonmagnetic metals, we find that an electrical current density of about 1010 to 1011 amperes per square metre induces magnetic switching in the nonmagnetic metals, with a large change in Hall voltage. In addition, the current polarity along the bias field and the sign of the spin Hall angle of the nonmagnetic metals-positive for Pt (ref. 21), close to 0 for Cu and negative for W (ref. 22)-determines the sign of the Hall voltage. Notably, the electrical switching in the antiferromagnet is achieved with the same protocol as that used for ferromagnetic metals23,24. Our results may lead to further scientific and technological advances in topological magnetism and antiferromagnetic spintronics.

4.
Nature ; 584(7822): E37, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32782392

RESUMO

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

5.
Nature ; 581(7806): 53-57, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32376952

RESUMO

Thermoelectric generation using the anomalous Nernst effect (ANE) has great potential for application in energy harvesting technology because the transverse geometry of the Nernst effect should enable efficient, large-area and flexible coverage of a heat source. For such applications to be viable, substantial improvements will be necessary not only for their performance but also for the associated material costs, safety and stability. In terms of the electronic structure, the anomalous Nernst effect (ANE) originates from the Berry curvature of the conduction electrons near the Fermi energy1,2. To design a large Berry curvature, several approaches have been considered using nodal points and lines in momentum space3-10. Here we perform a high-throughput computational search and find that 25 percent doping of aluminium and gallium in alpha iron, a naturally abundant and low-cost element, dramatically enhances the ANE by a factor of more than ten, reaching about 4 and 6 microvolts per kelvin at room temperature, respectively, close to the highest value reported so far. The comparison between experiment and theory indicates that the Fermi energy tuning to the nodal web-a flat band structure made of interconnected nodal lines-is the key for the strong enhancement in the transverse thermoelectric coefficient, reaching a value of about 5 amperes per kelvin per metre with a logarithmic temperature dependence. We have also succeeded in fabricating thin films that exhibit a large ANE at zero field, which could be suitable for designing low-cost, flexible microelectronic thermoelectric generators11-13.

6.
Proc Natl Acad Sci U S A ; 120(13): e2215030120, 2023 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-36952378

RESUMO

While the effective g-factor can be anisotropic due to the spin-orbit interaction (SOI), its existence in solids cannot be simply asserted from a band structure, which hinders progress on studies from such viewpoints. The effective g-factor in bismuth (Bi) is largely anisotropic; especially for holes at T-point, the effective g-factor perpendicular to the trigonal axis is negligibly small (<0.112), whereas the effective g-factor along the trigonal axis is very large (62.7). We clarified in this work that the large anisotropy of effective g-factor gives rise to the large spin conversion anisotropy in Bi from experimental and theoretical approaches. Spin-torque ferromagnetic resonance was applied to estimate the spin conversion efficiency in rhombohedral (110) Bi to be 17 to 27%, which is unlike the negligibly small efficiency in Bi(111). Harmonic Hall measurements support the large spin conversion efficiency in Bi(110). A large spin conversion anisotropy as the clear manifestation of the anisotropy of the effective g-factor is observed. Beyond the emblematic case of Bi, our study unveiled the significance of the effective g-factor anisotropy in condensed-matter physics and can pave a pathway toward establishing novel spin physics under g-factor control.

7.
BMC Cancer ; 24(1): 577, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38730358

RESUMO

BACKGROUND: Soft-tissue metastasis of carcinoma is rare. In the present study, we investigated the surgical indications and clinical features of patients with soft tissue metastases of carcinoma. METHODS: In this retrospective cohort study, we enrolled 26 patients with soft tissue carcinoma metastasis referred to our department for treatment. Sex, age, location, size, depth, pain due to the tumor, primary origin, serum C-reactive protein (CRP) level, MRI examinations, diagnosis by a previous physician, carcinoma markers from blood, history of carcinoma, other metastases, performance status (PS), and surgical procedures were documented. Associations between variables and surgery were statistically analyzed. RESULTS: The primary cancer origin was found to be the lung (n = 10), kidney (n = 7), esophagus (n = 2), stomach (n = 1), breast (n = 1), liver (n = 1), ureter (n = 1), anus (n = 1), and unknown (n = 2). The mean CRP level of all patients was 2.3 mg/dL. Seven tumors (26.9%) were originally suspected to be soft tissue metastases of carcinoma, while 19 tumors (73.1%) were considered soft tissue sarcomas or inflammatory lesions by the previous treating physician. Twenty patients (76.9%) had other metastases. The PS of the 12 patients (46.2%) was zero. Eleven patients (42.3%) underwent surgery for soft tissue metastases. Diagnosis of soft tissue metastasis by a previous physician and good PS (p < 0.05) were significantly associated with surgery. CONCLUSION: Overall, the present results show that surgical indications for soft tissue metastasis of carcinoma include diagnosis by the referring physician or good PS of the patients.


Assuntos
Neoplasias de Tecidos Moles , Humanos , Masculino , Feminino , Estudos Retrospectivos , Pessoa de Meia-Idade , Idoso , Neoplasias de Tecidos Moles/cirurgia , Neoplasias de Tecidos Moles/patologia , Neoplasias de Tecidos Moles/secundário , Adulto , Idoso de 80 Anos ou mais , Proteína C-Reativa/análise , Proteína C-Reativa/metabolismo , Carcinoma/cirurgia , Carcinoma/sangue , Carcinoma/patologia , Carcinoma/secundário , Imageamento por Ressonância Magnética
8.
Curr Treat Options Oncol ; 25(6): 784-797, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38750399

RESUMO

OPINION STATEMENT: Rhabdomyosarcoma, a soft tissue sarcoma commonly observed in childhood, requires multidisciplinary treatment, including surgical tumor resection, chemotherapy, and radiation therapy. Although long-term survival can be expected in patients with localized rhabdomyosarcoma, the clinical outcomes in patients with metastatic or unresectable rhabdomyosarcoma remain unsatisfactory. To improve the outcomes of rhabdomyosarcoma, it is important to explore effective systemic treatments for metastatic rhabdomyosarcoma. Currently, multiagent chemotherapy comprising vincristine, actinomycin D, and ifosfamide/cyclophosphamide remains standard systemic treatment for rhabdomyosarcoma. On the other hand, new treatment, such as immune checkpoint inhibitors and molecular targeted drugs, have demonstrated superior clinical outcomes compared to those of standard treatments in various type of malignancies. Therefore, it is necessary to assess the efficacies of these treatments in patients with rhabdomyosarcoma. Recent clinical studies have shown efficacies and safeties of temozolomide combined with vincristine/irinotecan, olaratumab combined with doxorubicin or vincristine/irinotecan, and long-term maintenance therapy. Furthermore, basic researches demonstrated new therapeutic targets. Future studies using these approaches are required to assess their clinical significances.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica , Rabdomiossarcoma , Humanos , Rabdomiossarcoma/terapia , Rabdomiossarcoma/diagnóstico , Rabdomiossarcoma/tratamento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Gerenciamento Clínico , Resultado do Tratamento , Terapia de Alvo Molecular , Terapia Combinada/métodos , Tomada de Decisão Clínica , Ensaios Clínicos como Assunto
9.
Int J Mol Sci ; 25(12)2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38928315

RESUMO

Due to the rarity and heterogeneity of sarcoma, investigation into molecular targets and new treatments has been particularly challenging [...].


Assuntos
Sarcoma , Sarcoma/diagnóstico , Sarcoma/terapia , Sarcoma/patologia , Humanos , Gerenciamento Clínico
10.
Cytotherapy ; 25(11): 1229-1235, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37486281

RESUMO

BACKGROUND AIMS: With the aim of strengthening the scientific evidence of immune-cell therapy for cancer and further examining its safety, in October 2015, our hospital jointly established the Cancer Immune-Cell Therapy Evaluation Group (CITEG) with 39 medical facilities nationwide. METHODS: Medical information, such as patients' background characteristics, clinical efficacy and therapeutic cell types obtained from each facility, has been accumulated, analyzed and evaluated by CITEG. In this prospective study, we analyzed the adverse events associated with immune-cell therapy until the end of September 2022, and we presented our interim safety evaluation. RESULTS: A total of 3839 patients with malignant tumor were treated with immune-cell therapy, with a median age of 64 years (range, 13-97 years) and a male-to-female ratio of 1:1.08 (1846:1993). Most patients' performance status was 0 or 1 (86.8%) at the first visit, and 3234 cases (84.2%) were advanced or recurrent cases, which accounted for the majority. The total number of administrations reported in CITEG was 31890, of which 960 (3.0%) showed adverse events. The numbers of adverse events caused by treatment were 363 (1.8%) of 19661 administrations of αßT cell therapy, 9 of 845 administrations of γδT-cell therapy (1.1%) and 10 of 626 administrations of natural killer cell therapy (1.6%). The number of adverse events caused by dendritic cell (DC) vaccine therapy was 578 of 10748 administrations (5.4%), which was significantly larger than those for other treatments. Multivariate analysis revealed that αßT cell therapy had a significantly greater risk of adverse events at performance status 1 or higher, and patients younger than 64 years, women or adjuvant immune-cell therapy had a greater risk of adverse events in DC vaccine therapy. Injection-site reactions were the most frequently reported adverse events, with 449 events, the majority of which were associated with DC vaccine therapy. Among all other adverse events, fever (228 events), fatigue (141 events) and itching (131 events) were frequently reported. In contrast, three patients had adverse events (fever, abdominal pain and interstitial pneumonia) that required hospitalization, although they were weakly related to this therapy; rather, it was considered to be the effect of treatment for the primary disease. CONCLUSIONS: Immune-cell therapy for cancer was considered to be a safe treatment without serious adverse events.


Assuntos
Neoplasias , Humanos , Masculino , Feminino , Adolescente , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Estudos Prospectivos , Neoplasias/terapia , Imunoterapia Adotiva , Resultado do Tratamento
11.
BMC Musculoskelet Disord ; 24(1): 454, 2023 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-37270505

RESUMO

BACKGROUND: A sclerosing epithelioid fibrosarcoma (SEF) is an uncommon tumor of the deep soft tissue. An SEF has been described as a low-grade tumor with high local recurrence and metastatic rates. Generally, in bone and soft tissue tumors, a resection of the biopsy route is recommended; however, there is limited evidence with respect to the dissemination of the tumor tissue during a needle biopsy. CASE PRESENTATION: A mass in the right pelvic cavity, with no symptoms, was observed in a 45-year-old woman during a gynecological examination. Computed tomography (CT) revealed a multilocular mass with calcification in the pelvic cavity. The magnetic resonance imaging (MRI) showed an iso-signal intensity on T1 weighted images and hypo- and iso-signal intensity on T2 weighted images. The CT-guided core needle biopsy was performed using a dorsal approach, and the biopsy diagnosis was a low-grade spindle cell tumor. The tumor was excised using an anterior approach. The tumor tissue comprised spindle cells and epithelioid cells with irregular nuclei, and the immunohistological analysis was positive for vimentin and epithelial membrane antigen, which was consistent with a diagnosis of sclerosing epithelioid fibrosarcoma. Five years after the surgery, the MRI showed a tumor recurrence in the subcutaneous tissue of the right buttock, which was consistent with the needle biopsy tract. The patient underwent a tumor excision, and the resected tumor was similar to the primary tumor. CONCLUSIONS: The recurrent tumor was excised with a surgical margin, and the tumor specimen had the histological features of a sclerosing epithelioid fibrosarcoma. It was difficult to investigate the association of the core needle biopsy with the tumor recurrence because the approach of the biopsy tract is usually same as that used in a tumor excision. However, the present case indicated the tumor may recur in the biopsy tract of a soft tissue sarcoma. Surgeons should be aware of the possibility of disseminating tumor tissues in a needle biopsy.


Assuntos
Fibrossarcoma , Sarcoma , Neoplasias de Tecidos Moles , Feminino , Humanos , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/diagnóstico por imagem , Recidiva Local de Neoplasia/cirurgia , Fibrossarcoma/diagnóstico por imagem , Fibrossarcoma/cirurgia , Biópsia , Neoplasias de Tecidos Moles/diagnóstico por imagem , Neoplasias de Tecidos Moles/cirurgia
12.
Int J Mol Sci ; 24(6)2023 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-36982907

RESUMO

Although the incidence of sarcomas accounts for less than 1% of all malignancies, they are classified into more than 50 different subtypes with different biological behaviours [...].


Assuntos
Sarcoma , Neoplasias de Tecidos Moles , Humanos , Patologia Molecular , Sarcoma/diagnóstico , Sarcoma/genética , Sarcoma/terapia , Incidência
13.
J Am Chem Soc ; 144(16): 7302-7307, 2022 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-35414173

RESUMO

Chirality-induced current-perpendicular-to-plane magnetoresistance (CPP-MR) originates from current-induced spin polarization in molecules. The current-induced spin polarization is widely recognized as a fundamental principle of chiral-induced spin selectivity (CISS). In this study, we investigate chirality-induced current-in-plane magnetoresistance (CIP-MR) in a chiral molecule/ferromagnetic metal bilayer at room temperature. In contrast to CPP-MR, CIP-MR observed in the present study requires no bias charge current through the molecule. The temperature dependence of CIP-MR suggests that thermally driven spontaneous spin polarization in chiral molecules is the key to the observed MR. The novel MR is consistent with recent CISS-related studies, that is, chiral molecules in contact with a metallic surface possess a finite spin polarization.

14.
Nat Mater ; 20(9): 1228-1232, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34083776

RESUMO

The spin-orbit interaction (SOI), mainly manifesting itself in heavy elements and compound materials, has been attracting much attention as a means of manipulating and/or converting a spin degree of freedom. Here, we show that a Si metal-oxide- semiconductor (MOS) heterostructure possesses Rashba-type SOI, although Si is a light element and has lattice inversion symmetry resulting in inherently negligible SOI in bulk form. When a strong gate electric field is applied to the Si MOS, we observe spin lifetime anisotropy of propagating spins in the Si through the formation of an emergent effective magnetic field due to the SOI. Furthermore, the Rashba parameter α in the system increases linearly up to 9.8 × 10-16 eV m for a gate electric field of 0.5 V nm-1; that is, it is gate tuneable and the spin splitting of 0.6 µeV is relatively large. Our finding establishes a family of spin-orbit systems.

15.
Clin Orthop Relat Res ; 480(12): 2442-2455, 2022 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-35976198

RESUMO

BACKGROUND: Under most circumstances, the resection of soft tissue sarcomas of the extremities can be limb-sparing, function-preserving oncologic resections with adequate margins. However, en bloc resection may require resection of the major peripheral nerves, causing poor function in the extremities. Although liquid nitrogen treatment has been used to sterilize malignant bone tumors, its use in the preparation of nerve grafts has, to our knowledge, not been reported. Hence, this study aimed to investigate the tumor recurrence and function after peripheral nerve reconstruction using liquid nitrogen-treated tumor-bearing nerves in a rat model. QUESTIONS/PURPOSES: (1) Do liquid nitrogen-treated frozen autografts have regeneration capabilities? (2) Do liquid nitrogen-treated tumor-bearing nerves cause any local recurrences in vivo in a rat model? METHODS: Experiment 1: Twelve-week-old female Wistar rats, each weighing 250 g to 300 g, were used. A 10-mm-long section of the right sciatic nerve was excised; the prepared nerve grafts were bridge-grafted through end-to-end suturing. The rats were grouped as follows: an autograft group, which underwent placement of a resected sciatic nerve after it was sutured in the reverse orientation, and a frozen autograft group, which underwent bridging of the nerve gap using a frozen autograft. The autograft was frozen in liquid nitrogen, thawed at room temperature, and then thawed in distilled water before application. The third group was a resection group in which the nerve gap was not reconstructed. Twenty-four rats were included in each group, and six rats per group were evaluated at 4, 12, 24, and 48 weeks postoperatively. To assess nerve regeneration after reconstruction using the frozen nerve graft in the nontumor rat model, we evaluated the sciatic functional index, tibialis anterior muscle wet weight ratio, electrophysiologic parameters (amplitude and latency), muscle fiber size (determined with Masson trichrome staining), lower limb muscle volume, and immunohistochemical findings (though neurofilament staining and S100 protein produced solely and uniformly by Schwann cells associated with axons). Lower limb muscle volume was calculated via CT before surgery (0 weeks) and at 4, 8, 12, 16, 20, 24, 32, 40, and 48 weeks after surgery. Experiment 2: Ten-week-old female nude rats (F344/NJcl-rnu/rnu rats), each weighing 100 g to 150 g, were injected with HT1080 (human fibrosarcoma) cells near the bilateral sciatic nerves. Two weeks after injection, the tumor grew to a 10-mm-diameter mass involving the sciatic nerves. Subsequently, the tumor was resected with the sciatic nerves, and tumor-bearing sciatic nerves were obtained. After liquid nitrogen treatment, the frozen tumor-bearing nerve graft was trimmed to a 5-mm-long tissue and implanted into another F344/NJcl-rnu/rnu rat, in which a 5-mm-long section of the sciatic nerve was resected to create a nerve gap. Experiment 2 was performed with 12 rats; six rats were evaluated at 24 and 48 weeks postoperatively. To assess nerve regeneration and tumor recurrence after nerve reconstruction using frozen tumor-bearing nerve grafts obtained from the nude rat with human fibrosarcoma involving the sciatic nerve, the sciatic nerve's function and histologic findings were evaluated in the same way as in Experiment 1. RESULTS: Experiment 1: The lower limb muscle volume decreased once at 4 weeks in the autograft and frozen autograft groups and gradually increased thereafter. The tibialis anterior muscle wet weight ratio, sciatic functional index, muscle fiber size, and electrophysiologic evaluation showed higher nerve regeneration potential in the autograft and frozen autograft groups than in the resection group. The median S100-positive areas (interquartile range [IQR]) in the autograft group were larger than those in the frozen autograft group at 12 weeks (0.83 [IQR 0.78 to 0.88] versus 0.57 [IQR 0.53 to 0.61], difference of medians 0.26; p = 0.04) and at 48 weeks (0.86 [IQR 0.83 to 0.99] versus 0.74 [IQR 0.69 to 0.81], difference of median 0.12; p = 0.03). Experiment 2: Lower limb muscle volume decreased at 4 weeks and gradually increased thereafter. The median muscle fiber size increased from 0.89 (IQR 0.75 to 0.90) at 24 weeks to 1.20 (IQR 1.08 to 1.34) at 48 weeks (difference of median 0.31; p< 0.01). The median amplitude increased from 0.60 (IQR 0.56 to 0.67) at 24 weeks to 0.81 (IQR 0.76 to 0.90) at 48 weeks (difference of median 0.21; p < 0.01). Despite tumor involvement and freezing treatment, tumor-bearing frozen grafts demonstrated nerve regeneration activity, with no local recurrence observed at 48 weeks postoperatively in nude rats. CONCLUSION: Tumor-bearing frozen nerve grafts demonstrated nerve regeneration activity, and there was no tumor recurrence in rats in vivo. CLINICAL RELEVANCE: A frozen nerve autograft has a similar regenerative potential to that of a nerve autograft. Although the findings in a rat model do not guarantee efficacy in humans, if they are substantiated by large-animal models, clinical trials will be needed to evaluate the efficacy of tumor-bearing frozen nerve grafts in humans.


Assuntos
Fibrossarcoma , Nitrogênio , Ratos , Humanos , Feminino , Animais , Ratos Nus , Ratos Wistar , Ratos Endogâmicos F344 , Recidiva Local de Neoplasia/patologia , Nervo Isquiático/cirurgia , Nervo Isquiático/patologia , Regeneração Nervosa/fisiologia , Fibrossarcoma/patologia
16.
BMC Musculoskelet Disord ; 23(1): 170, 2022 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-35193563

RESUMO

BACKGROUND: Giant cell tumor of bone (GCTB) is an intermediate tumor commonly arising from the epiphysis of the distal femur and proximal tibia. Standard GCTB treatment is joint-preserving surgery performed using thorough curettage and the filling of the cavity with allo-, auto-, polymethyl methacrylate (PMMA), or synthetic bone graft. Calcium phosphate cement (CPC) is an artificial bone substitute, which has the benefit of being able to adjust defects, consequently inducing immediate mechanical strength, and promoting biological healing. Secondary osteoarthritis may occur following GCTB treatment and may need additional surgery if severe. However, details regarding surgery for secondary osteoarthritis have not been fully elucidated. There are no reports on the use of total knee arthroplasty (TKA) for the treatment of secondary osteoarthritis following CPC packing. The insertion of an alignment rod is a standard procedure in TKA; however, it was difficult to perform in this case due to CPC. Therefore, we used a computed tomography (CT)-free navigation system to assist the distal femur cut. This study presents a knee joint secondary osteoarthritis case following CPC packing for GCTB curettage that was treated with standard TKA. CASE PRESENTATION: A 67-year-old Japanese woman, who was previously diagnosed with left distal femur GCTB and was treated by curettage and CPC packing 7 years ago, complained of severe knee pain. Left knee joint plain radiography revealed Kellgren and Lawrence (K-L) grade 4 osteoarthritis without evidence of tumor recurrence. Therefore, she was scheduled for TKA. There are no reports on the cutting of a femoral condyle surface with massive CPC with accurate alignment. Because it is difficult to insert the alignment rod intramedullary and cut the femoral condyle with CPC, we planned CT-free navigation-guided surgery for accurate bone cutting using an oscillating tip saw system to prevent CPC cracks. We performed standard TKA without complications, as planned. Postoperative X-ray showed normal alignment. Knee Society Knee Score (KSKS) and Knee Society Function Score (KSFS) ameliorated from 27 and 29 to 64 and 68, respectively The patient can walk without a cane postoperatively. CONCLUSION: There was no report about the surface TKA guided by CT-free navigation after primary GCT surgery with CPC. We believe that this case report will help in planning salvage surgery for secondary osteoarthritis after CPC packing.


Assuntos
Artroplastia do Joelho , Tumor de Células Gigantes do Osso , Osteoartrite do Joelho , Idoso , Artroplastia do Joelho/efeitos adversos , Artroplastia do Joelho/métodos , Fosfatos de Cálcio/uso terapêutico , Feminino , Fêmur/diagnóstico por imagem , Fêmur/cirurgia , Tumor de Células Gigantes do Osso/cirurgia , Humanos , Articulação do Joelho/diagnóstico por imagem , Articulação do Joelho/patologia , Articulação do Joelho/cirurgia , Osteoartrite do Joelho/diagnóstico por imagem , Osteoartrite do Joelho/patologia , Osteoartrite do Joelho/cirurgia , Estudos Retrospectivos , Tíbia/diagnóstico por imagem , Tíbia/patologia , Tíbia/cirurgia , Tomografia Computadorizada por Raios X
17.
Int J Mol Sci ; 23(3)2022 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-35163019

RESUMO

Due to resistance to standard anticancer agents, it is difficult to control the disease progression in patients with metastatic or unresectable chondrosarcoma. Novel therapeutic approaches, such as molecule-targeting drugs and immunotherapy, are required to improve clinical outcomes in patients with advanced chondrosarcoma. Recent studies have suggested several promising biomarkers and therapeutic targets for chondrosarcoma, including IDH1/2 and COL2A1. Several molecule-targeting agents and immunotherapies have shown favorable antitumor activity in clinical studies in patients with advanced chondrosarcomas. This review summarizes recent basic studies on biomarkers and molecular targets and recent clinical studies on the treatment of chondrosarcomas.


Assuntos
Antineoplásicos/uso terapêutico , Neoplasias Ósseas/tratamento farmacológico , Condrossarcoma/tratamento farmacológico , Colágeno Tipo II/antagonistas & inibidores , Isocitrato Desidrogenase/antagonistas & inibidores , Mutação , Biomarcadores Tumorais/antagonistas & inibidores , Biomarcadores Tumorais/genética , Neoplasias Ósseas/metabolismo , Neoplasias Ósseas/patologia , Condrossarcoma/metabolismo , Condrossarcoma/patologia , Colágeno Tipo II/genética , Humanos , Isocitrato Desidrogenase/genética
18.
Int J Mol Sci ; 23(16)2022 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-36012709

RESUMO

We investigated the abscopal effect after cryoablation (CA) on bone metastasis using a mouse model. Breast cancer cells were implanted in the bilateral tibiae of mice. The left tumor was treated locally with CA, and the right abscopal tumor (AT) was left untreated. The mice were divided into four groups based on the combination of CA and intraperitoneal administration of anti-PD-1 antibody (PD) as treatment interventions (Control, CA, PD, and CA + PD). The reduction ratio of the size of AT, the quantitative immune effects at enzyme-linked immunospot (ELISPOT) assay, and the intensity of infiltration of immune-related cells to AT were compared among the groups. CA alone showed a significant immunoenhancing effect on the volume change ratio of AT from day 0 to day 14 (Control-CA: p < 0.05), ELISPOT assay (Control-CA: p < 0.01), and CD4+ cell count in immunostaining (Control-CA: p < 0.05). CA alone showed no significant immunoenhancing effect on CD8+ and Foxp3+ cell counts in immunostaining, but the combination of CA and PD showed a significant immunoenhancing effect (Control-CA + PD: p < 0.01 [CD8, Foxp3]). The results suggested that the abscopal effect associated with the local cryotherapy of metastatic bone tumors was activated by CA and enhanced by its combination with PD.


Assuntos
Neoplasias Ósseas , Criocirurgia , Animais , Neoplasias Ósseas/terapia , Linfócitos T CD8-Positivos , Criocirurgia/métodos , Modelos Animais de Doenças , Fatores de Transcrição Forkhead
19.
BMC Cancer ; 21(1): 773, 2021 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-34217231

RESUMO

BACKGROUND: Synovial sarcoma is an aggressive but chemosensitive soft-tissue tumor. We retrospectively analyzed the efficacy of perioperative chemotherapy for synovial sarcoma with data from the nationwide database, Bone and Soft Tissue Tumor Registry in Japan. METHODS: This study included 316 patients diagnosed with synovial sarcoma between 2006 and 2012. Oncologic outcomes were analyzed using a Cox-hazard regression model. Moreover, the effects of perioperative chemotherapy on outcomes were evaluated using a matched-pair analysis. The oncologic outcomes of patients who did or did not receive chemotherapy were compared (cx + and cx-). RESULTS: Multivariate analysis revealed significant correlations of age (over 40, hazard ratio [HR] = 0.61, p = 0.043), margin status (marginal resection, HR = 0.18, p < 0.001 and intralesional resection, HR = 0.30, p = 0.013 versus wide resection) with overall survival; surgical margin type (marginal resection, HR = 0.14, p = 0.001 and intralesional resection, HR = 0.09, p = 0.035 versus wide resection) with local recurrence; and postoperative local recurrence (HR = 0.30, p = 0.027) and surgical margin (marginal resection, HR = 0.31, p = 0.023 versus wide resection) with distant relapse-free survival. Before propensity score matching, perioperative chemotherapy was mainly administered for young patients and patients with deeper tumor locations, larger tumors, more advanced-stage disease, and trunk location. The 3-year overall survival, local control, and distant relapse-free survival rates were 79.8%/89.3% (HR = 0.64, p = 0.114), 89.6%/93.0% (HR = 0.37, p = 0.171) and 71.4%/84.5% (HR = 0.60, p = 0.089) in the cx+/cx- groups, respectively. After propensity score matching, 152 patients were selected such that the patient demographics were nearly identical in both groups. The 3-year overall survival, local control, and distant relapse-free survival rates were 71.5%/86.0% (HR = 0.48, p = 0.055), 92.5%/93.3% (HR = 0.51, p = 0.436) and 68.4%/83.9% (HR = 0.47, p = 0.046) in the cx+/cx- groups, respectively. CONCLUSION: This large-sample study indicated that the margin status and postoperative disease control were associated directly or indirectly with improved oncologic outcomes. However, the efficacy of perioperative chemotherapy for survival outcomes in synovial sarcoma patients was not proven in this Japanese database analysis.


Assuntos
Sarcoma Sinovial/tratamento farmacológico , Adulto , Bases de Dados Factuais , Feminino , Humanos , Japão , Masculino , Análise por Pareamento , Período Perioperatório , Estudos Retrospectivos
20.
Calcif Tissue Int ; 108(6): 819-824, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33555353

RESUMO

Camurati-Engelmann disease (CED) is a rare, progressive diaphyseal dysplasia characterized as diaphyseal hyperostosis and sclerosis of the long bones. Corticosteroids, bisphosphonates, and losartan have been reported to be effective systemic medications used to reduce CED symptoms. There are no reports of osteoblastoma in patients with CED, and osteoblastoma in the distal radius is rare. We present a patient diagnosed with CED, based on radiological and histological examinations, at 11 years old. At 22 years old, she experienced severe pain in her right forearm and was treated with bisphosphonate, losartan, and prednisolone; however, the pain continued. An expansive and sclerotic lesion at the distal radius was observed on radiography. A follow-up plain radiograph indicated that the lesion was growing. Fluorodeoxyglucose positron emission tomography revealed solitary, intense radiotracer uptake, and a biopsy and surgical resection were performed due to suspected malignancy. Pathologic analysis showed anastomosing bony trabeculae rimmed by osteoblasts observed in a loose fibrovascular stroma. The lesion was diagnosed as an osteoblastoma. Following bone excision and artificial bone grafting, the patient's severe pain almost completely disappeared. At final follow-up, no evidence of osteoblastoma recurrence was noted. To our knowledge, this is the first case report of osteoblastoma arising in a patient with CED. Bone excision and artificial bone grafting may be a treatment option for local symptomatic osteoblastoma in patients with CED.


Assuntos
Neoplasias Ósseas , Síndrome de Camurati-Engelmann , Osteoblastoma , Neoplasias Ósseas/cirurgia , Síndrome de Camurati-Engelmann/diagnóstico por imagem , Síndrome de Camurati-Engelmann/cirurgia , Feminino , Humanos , Recidiva Local de Neoplasia , Osteoblastoma/cirurgia , Radiografia , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA