Determination of Stokes vector from a single image acquisition

Four Stokes parameters (1852) define the polarisation state of light. Measured changes of the Stokes vector of light traversing an inhomogeneous sample are linked to the local anisotropies of absorption and refraction and are harnessed over an increasing range of applications in photonics, material, and space/earth observation. Several independent polarisation sensitive measurements are usually required for determination of the all four Stokes parameters, which makes such characterisation procedure time-consuming or requires complex setups. Here we introduce a single-snapshot approach to Stokes polarimetry in transmission by use of a 4-polarisation camera with the on-chip integrated polarisers. A quarter-waveplate was added in front of the sample and was illuminated by a linearly polarised light. This approach is demonstrated by measuring birefringence $\Delta n\sim 0.012$ of spider silk of only $\sim 6~\mu$m-diameter using microscopy, however, due to its generic nature, it is transferable to other spectral ranges and imaging applications, e.g., imaging from a fast moving satellite or drone or monitoring fast changing events such as phase transitions.Comment: 9 pages, 8 figure

Permanent pacemaker lead placement via the femoral vein in an elderly patient with a large thoracic aortic aneurysm

AbstractAn 87-year-old woman with complete atrioventricular block was admitted for permanent pacemaker implantation. The patient had a large thoracic aortic aneurysm that had been conservatively treated. Lead placement was not possible via the superior vena cava or the epicardial route because of the aneurysm. Therefore, we implanted a VVI pacemaker via the femoral approach. A unit was placed in a pouch on the right lower abdominal wall, and a lead was introduced into the right ventricle via the right femoral vein. The femoral vein approach is rarely used; however, it should be recognized as an effective alternative when the usual approach is difficult or impossible to be performed

Quadruple coaxial catheter system on transvenous embolization for dural arteriovenous fistula

Background: Although transvenous embolization (TVE) is an effective method for treating dural arteriovenous fistula (AVF), directing the catheter to the lesion site is difficult.Objective: We report on the utility of a quadruple coaxial catheter system for TVE.Materials and methods: The quadruple catheter system comprised a 6 Fr guiding sheath, 6 Fr guiding catheter, 4 Fr intermediate catheter, and a regular microcatheter. The system was utilized in 27 consecutive dural AVF cases treated with TVE. In this study, we reviewed our experience with this system, including the theory, method of use, and complications.Results: Stenosis or obstruction of the vascular access was identified in 12 cases. The catheter could not reach to the lesion in three cases of cavernous sinus (7.4%); therefore, transarterial embolization was employed. Angiographic results revealed that the cases consist of total occlusion (n = 16, 59.5%), subtotal (n = 10, 37.0%), and partial occlusion (n = 1, 3.7%). Complete resolution or improvement of symptoms was observed in 23 patients (85.2%), no improvement of symptoms was observed in three patients (7.4%), and deterioration of symptoms was observed in one patient (3.7%). Venous perforation occurred in one patient without any neurological deficit. The catheter system provided access to the lesion and provided stability during the mechanically demanding process navigating the catheter and placing the coils.Conclusion: We determined that the quadruple coaxial system was safe and efficient for TVE for dural AVF

転載:新生仔マウス高濃度酸素暴露肺障害モデルにおける肺胞微小血管障害の形態学的特徴

臨時増刊1号東京女子医科大学医学部解剖学・発生生物学講座 講座主任 江﨑太一教授退任記念特別

A case of primary small cell carcinoma of the liver that was treated with chemotherapy

Primary small cell carcinoma (SSC) of the liver is very rare in Japan and only ten cases have been reported worldwide. We report herein the case of a 77-year-old man with primary SCC of the liver. He had a tumor over 10 cm in diameter which was localized in the right lobe of the liver and had invaded the right diaphragm. In laboratory tests, high serum levels of lactate dehydrase and neuron-specific enolase were observed. A biopsy specimen showed that the tumor cells were similar in cytology to a pulmonary SCC. The patient was first treated with carboplatin and etoposide according to the therapy protocol for pulmonary SCC and then with a regimen using etoposid and cisplatinum, resulting in an unfavorable outcome. We discuss the clinical course and therapy of extra-pulmonary SCC and review the literature of the cases previously reported

Tumour micro-environment elicits innate resistance to RAF inhibitors through HGF secretion.

Drug resistance presents a challenge to the treatment of cancer patients. Many studies have focused on cell-autonomous mechanisms of drug resistance. By contrast, we proposed that the tumour micro-environment confers innate resistance to therapy. Here we developed a co-culture system to systematically assay the ability of 23 stromal cell types to influence the innate resistance of 45 cancer cell lines to 35 anticancer drugs. We found that stroma-mediated resistance is common, particularly to targeted agents. We characterized further the stroma-mediated resistance of BRAF-mutant melanoma to RAF inhibitors because most patients with this type of cancer show some degree of innate resistance. Proteomic analysis showed that stromal cell secretion of hepatocyte growth factor (HGF) resulted in activation of the HGF receptor MET, reactivation of the mitogen-activated protein kinase (MAPK) and phosphatidylinositol-3-OH kinase (PI(3)K)-AKT signalling pathways, and immediate resistance to RAF inhibition. Immunohistochemistry experiments confirmed stromal cell expression of HGF in patients with BRAF-mutant melanoma and showed a significant correlation between HGF expression by stromal cells and innate resistance to RAF inhibitor treatment. Dual inhibition of RAF and either HGF or MET resulted in reversal of drug resistance, suggesting RAF plus HGF or MET inhibitory combination therapy as a potential therapeutic strategy for BRAF-mutant melanoma. A similar resistance mechanism was uncovered in a subset of BRAF-mutant colorectal and glioblastoma cell lines. More generally, this study indicates that the systematic dissection of interactions between tumours and their micro-environment can uncover important mechanisms underlying drug resistance

Restriction of intestinal stem cell expansion and the regenerative response by YAP

A remarkable feature of regenerative processes is their ability to halt proliferation once an organ’s structure has been restored. The Wnt signaling pathway is the major driving force for homeostatic self-renewal and regeneration in the mammalian intestine. The mechanisms that counterbalance Wnt-driven proliferation are poorly understood. We demonstrate here that YAP, a protein known for its powerful growth-inducing and oncogenic properties1-2, has an unexpected growth-suppressive function restricting Wnt signals during intestinal regeneration. Transgenic expression of YAP reduces Wnt target gene expression and results in the rapid loss of intestinal crypts. In addition, loss of YAP results in Wnt hypersensitivity during regeneration, leading to hyperplasia, expansion of intestinal stem cells (ISCs) and niche cells, and formation of ectopic crypts and microadenomas. We find that cytoplasmic YAP restricts elevated Wnt signaling independently of the APC/Axin/GSK3β complex partly by limiting the activity of Dishevelled (DVL). DVL signals in the nucleus of ISCs and its forced expression leads to enhanced Wnt signaling in crypts. YAP dampens Wnt signals by restricting DVL nuclear translocation during regenerative growth. Finally, we provide evidence that YAP is silenced in a subset of highly aggressive and undifferentiated human colorectal carcinomas (CRC) and its expression can restrict the growth of CRC xenografts. Collectively, our work describes a novel mechanistic paradigm for how proliferative signals are counterbalanced in regenerating tissues. Additionally, our findings have important implications for the targeting of YAP in human malignancies

Calaxin is required for cilia-driven determination of vertebrate laterality

Sasaki, K., Shiba, K., Nakamura, A. et al. Calaxin is required for cilia-driven determination of vertebrate laterality. Commun Biol 2, 226 (2019). https://doi.org/10.1038/s42003-019-0462-