Amyloidosis is a protein conformational disorder with the distinctive feature of extracellular accumulation of amyloid fibrils that come from different proteins. In the ligamentum flavum of the lumbar spine, amyloid deposits were frequently found in elderly patients with lumbar spinal canal stenosis and were at least partially formed by wild-type transthyretin. However, how amyloid deposits in the ligamentum flavum affect lumbar spinal canal stenosis has remained unclear. In this study, we analyzed clinical, pathologic, and radiologic findings of patients with lumbar spinal canal stenosis who had amyloid deposits in the ligamentum flavum. We studied 95 ligamentum flavum specimens obtained from 56 patients with lumbar spinal canal stenosis and 21 ligamentum flavum specimens obtained from 19 patients with lumbar disk herniation. We evaluated histopathologic findings and clinicoradiologic manifestations, such as thickness of the ligamentum flavum and lumbar spinal segmental instability. We found that all 95 ligamentum flavum specimens resected from patients with lumbar spinal canal stenosis had amyloid deposits, which we classified into two types, transthyretin-positive and transthyretinnegative, and that transthyretin amyloid formation in the ligamentum flavum of patients with lumbar spinal canal stenosis was an age-associated phenomenon. The amount of amyloid in the ligamentum flavum was related to clinical manifestations of lumbar spinal canal stenosis, such as thickness of the ligamentum flavum and lumbar spinal segmental instability, in the patients with lumbar spinal canal stenosis with transthyretin-positive amyloid deposits. To our knowledge, this report is the first to show clinicopathologic correlations in transthyretin amyloid deposits of the ligamentum flavum. In conclusion, transthyretin amyloid deposits in the ligamentum flavum may be related to the pathogenesis of lumbar spinal canal stenosis in elderly patients.
Lymph node metastasis is associated with resistance to conventional therapy and poor survival of patients with oral squamous cell carcinoma (OSCC). Although lymphangiogenesis is well known to be associated with the occurrence of lymph node metastasis in various cancers, the precise mechanisms of lymphangiogenesis in OSCC are largely unknown. IL-6, a potent pro-inflammatory cytokine, has been shown to play active roles in various cancers, including OSCC. This study aimed to investigate the involvement of IL-6 signalling in lymphatic metastasis and to evaluate the efficacy of tocilizumab, a humanized anti-human IL-6 receptor antibody, as an anti-lymphangiogenic agent for OSCC. This investigation confirmed that levels of expression of IL-6 protein and VEGF-C mRNA in OSCC tissues were significantly correlated with lymph node metastasis in patients with OSCC, as assessed by immunohistochemical analysis and real-time quantitative RT-PCR. In vitro studies showed that IL-6 regulated VEGF-C mRNA expression in a human OSCC cell line, SAS cells, through the phosphoinositide 3-kinase-Akt pathway. In addition, treatment with tocilizumab led to markedly reduced VEGF-C mRNA expression and OSCC-related lymphangiogenesis in SAS xenografts. Together, these data suggest that tocilizumab acted as expected: it inhibited lymph node metastasis in OSCC by reducing tumour lymphangiogenesis.
This study is the first to show the clinical significance of stromal NGAL expression, which may be an indicator of poor prognosis and more aggressive histological grade in OSCC. Our data suggest that NGAL expression in tumour cells and expression in stroma are associated in different ways with OSCC differentiation.
Synopsis: The effects of columnar defects on the critical current density (J c) and electric field (E) vs. current density (J) characteristics were investigated for a YBa 2 Cu 3 O y thin film prepared using a pulsed-laser deposition method. The YBa 2 Cu 3 O y thin film was irradiated with 200 MeV Au ions from a direction = 8.8° off the c-axis. Two peaks in the angular dependence of J c were observed at the angles of = 8.8° and = 90°. These angles correspond to the directions of the columnar defect and intrinsic pinning, respectively. The E-J characteristics at various magnetic field angles can be described by the percolation transition model. The value of pinning parameter m increases at the angles of = 8.8° and = 90°. This result indicates that the efficiency of flux pinning is enhanced because fluxoids are effectively pinned by the columnar defects and intrinsic pinning or stacking faults in these directions.
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