MCA morphology and BAD

Introduction : Branch atheromatous disease (BAD) is a type of cerebral infarction caused by stenosis or occlusion at the entrance of the penetrating branch due to the presence of plaque. Despite its clinical significance, it is not clear how these plaques are formed. Focal geometrical characteristics are expected to be as important as vascular risk factors in the development of atherosclerosis. This study aimed to analyze the association between middle cerebral artery (MCA) geometric features and the onset of BAD. Shear stress results from the blood flow exerting force on the inner wall of the vessels and places with low wall shear stress may be prone to atherosclerosis. At the curvature of blood vessels, the shear stress is weak on the inside of the curve and plaque is likely to form. When this is applied to the MCA M1 segment, downward type M1 is likely to form plaques on the superior side. Because the lenticulostriate artery usually branches off from the superior side of the MCA M1 segment, in downward type M1, a plaque is likely to be formed at the entrance of the penetrating branch, and for that reason, BAD is likely to onset. Methods : We retrospectively reviewed hospitalized stroke patients with BAD and investigated the morphology of their MCA using magnetic resonance imaging. The M1 segment was classified as straight or curved. Additionally, we compared the difference between the symptomatic and the asymptomatic side. Data regarding patients’ medical history were also collected. Results : A total of 56 patients with lenticulostriate artery infarctions and BAD were analyzed. On the symptomatic side, downward type M1 accounted for the largest proportion at 44%, whereas on the asymptomatic side, it was the lowest, at 16%. Conclusion : A downward type MCA may be associated with the onset of BAD and the morphological characteristics might affect the site of plaque formation

Application of precise neutron focusing mirrors for neutron reflectometry: latest results and future prospects

超精密中性子集束ミラーによる電極界面のナノ構造解析技術の実用化 --測定精度の劇的な向上に向けた大きなマイルストーン--. 京都大学プレスリリース. 2020-10-28.Neutron reflectometry (NR) is a powerful tool for providing insight into the evolution of interfacial structures, for example via operando measurements for electrode–electrolyte interfaces, with a spatial resolution of nanometres. The time resolution of NR, which ranges from seconds to minutes depending on the reflection intensity, unfortunately remains low, particularly for small samples made of state-of-the-art materials even with the latest neutron reflectometers. To overcome this problem, a large-area focusing supermirror manufactured with ultra-precision machining has been employed to enhance the neutron flux at the sample, and a gain of approximately 100% in the neutron flux was achieved. Using this mirror, a reflectivity measurement was performed on a thin cathode film on an SrTiO3 substrate in contact with an electrolyte with a small area of 15 × 15 mm. The reflectivity data obtained with the focusing mirror were consistent with those without the mirror, but the acquisition time was shortened to half that of the original, which is an important milestone for rapid measurements with a limited reciprocal space. Furthermore, a method for further upgrades that will reveal the structural evolution with a wide reciprocal space is proposed, by applying this mirror for multi-incident-angle neutron reflectometry

Evaluating the Safety of Simultaneous Intracranial Electroencephalography and Functional Magnetic Resonance Imaging Acquisition Using a 3 Tesla Magnetic Resonance Imaging Scanner

Background: The unsurpassed sensitivity of intracranial electroencephalography (icEEG) and the growing interest in understanding human brain networks and ongoing activities in health and disease have make the simultaneous icEEG and functional magnetic resonance imaging acquisition (icEEG-fMRI) an attractive investigation tool. However, safety remains a crucial consideration, particularly due to the impact of the specific characteristics of icEEG and MRI technologies that were safe when used separately but may risk health when combined. Using a clinical 3-T scanner with body transmit and head-receive coils, we assessed the safety and feasibility of our icEEG-fMRI protocol. Methods: Using platinum and platinum-iridium grid and depth electrodes implanted in a custom-made acrylic-gel phantom, we assessed safety by focusing on three factors. First, we measured radio frequency (RF)-induced heating of the electrodes during fast spin echo (FSE, as a control) and the three sequences in our icEEG-fMRI protocol. Heating was evaluated with electrodes placed orthogonal or parallel to the static magnetic field. Using the configuration with the greatest heating observed, we then measured the total heating induced in our protocol, which is a continuous 70-min icEEG-fMRI session comprising localizer, echo-planar imaging (EPI), and magnetization-prepared rapid gradient-echo sequences. Second, we measured the gradient switching-induced voltage using configurations mimicking electrode implantation in the frontal and temporal lobes. Third, we assessed the gradient switching-induced electrode movement by direct visual detection and image analyses. Results: On average, RF-induced local heating on the icEEG electrode contacts tested were greater in the orthogonal than parallel configuration, with a maximum increase of 0.2°C during EPI and 1.9°C during FSE. The total local heating was below the 1°C safety limit across all contacts tested during the 70-min icEEG-fMRI session. The induced voltage was within the 100-mV safety limit regardless of the configuration. No gradient switching-induced electrode displacement was observed. Conclusion: We provide evidence that the additional health risks associated with heating, neuronal stimulation, or device movement are low when acquiring fMRI at 3 T in the presence of clinical icEEG electrodes under the conditions reported in this study. High specific absorption ratio sequences such as FSE should be avoided to prevent potential inadvertent tissue heating

A P2P algorithm for extraction of Gazing Area

本研究では, イベント会場などの同一時刻に近隣地域に存在する複数のカメラ付き情報端末による即席の動画共有システムを提案する. 特に注目すべき事象が存在する領域(注視領域) の探索を想定し, その処理を近傍の端末によりアドホックに構成されたP2P オーバレイネットワーク上で実行する手法について述べる. また, 各カメラの位置とその撮影領域を管理する為の基盤としてP2P ドロネーネットワークを用いる. P2P ドロネーネットワークは,アドホックに作成された簡便なネットワークから分散的な構築アルゴリズムにより構築できる. この為, 本提案システムは専用の計算機資源を用いない. 本研究で提案する手法は, 環状ネットワークの構築手法, P2P ドロネーネットワークの構築手法, 各カメラの撮影領域情報のノードへの分配手法, 各ノードで求めた共通撮影領域情報から分散的に注視領域を求める手法, 全参加ノードに対して最終的な領域を通知する手法から成る. 各カメラ付き情報端末は, GPS, 電子コンパスなどにより, 自身の撮影領域の情報を求める. 次に各ノードは撮影領域内を管理する他のノードに対して,フラッディングにより撮影領域情報を転送する. 各ノードは受け取った撮影領域情報元に, 自身の管理領域内の注視領域についての計算を行う. その後, 環状ネットワーク上で分散的に領域を撮影しているカメラ台数の最大値を求めることにより, 最も注目されている領域を求める. また, シミュレーションにより各ノードに対する計算負荷, 通信負荷についての評価を行う.DEWS2007 c8-6 電子情報通信学会 第18回データ工学ワークショップ 2007年2月28日～2007年3月2日正式版リンクwww.ieice.org/~de/DEWS/DEWS2007/pdf/c8-6.pd

Preoperative simulation with a 3-dimensional printed solid model for one-step reconstruction of multiple hepatic veins during living donor liver transplantation

Meticulous preoperative volumetry of the partial liver graft is essential for both assessing the postoperative graft function and to ensure the donor safety in the field of living donor liver transplantation (LDLT).We herein report the case of a 53-year-old patient who underwent LDLT for hepatitis C virusinfected liver cirrhosis complicated with hepatocellular carcinoma. Preoperative 3D images were obtained using a 3D image analysis system to evaluate the graft volume and possible congested volume after implantation in LDLT, which revealed that a large middle hepatic vein drained a vast area in the right lobe. The extended left graft was considered to be small for size of the recipient, with an estimated congested area of 407 ml, which was equivalent to 39% of the donor’s liver volume in the remnant right lobe.We decided to use a right lobe graft with the middle hepatic vein, because the volume was considered to be sufficient. A preoperative contrast-enhanced CT scan revealed a distance of 2 cm between the donor’s right hepatic vein and middle hepatic vein at the estimated Cantlie line. Because of the location, we planned to use autologous portal vein Y-graft interposition for the hepatic venous anastomosis. Three-dimensional printed solid models of the donor’s right lobe graft and the Y-graft from the recipient’s portal vein were also made for preoperative simulation using the Vincent program.Based on the estimation, we were able to evaluate whether to reconstruct the middle hepatic vein tributaries or anomalous hepatic veins in LDLT. The 3D solid model was effective for preoperative simulation and planning, which made it easy to imagine the reconstructed shape of the anastomosis with appropriate spatial perception

The SNP rs6508974 in AXL is a functional polymorphism and a promising biomarker for gefitinib treatment

Somatic mutations in epidermal growth factor receptor (EGFR) found in lung adenocarcinomas are used as biomarkers for the treatment with EGFR-tyrosine kinase inhibitors, including gefitinib. The bypass tracks with amplification of AXL is one of the mechanisms underlying the resistance to gefitinib. We, therefore, carried out a candidate gene approach method to identify AXL polymorphisms associated with the effectiveness of gefitinib. EGFR mutations were first dentified by mutantenriched PCR-restriction fragment length polymorphism (RFLP), and then 2 tag single nucleotide olymorphisms (SNPs) of AXL were examined by PCR-RFLP in 62 Japanese patients with advanced lung adenocarcinoma and treated with gefitinib in two general hospitals in Nagasaki. Subsequently, the association of EFGR mutations and the AXL polymorphism with the effectiveness of gefitinib was examined in these patients. We next examined the effect of the AXL polymorphism on the expression and function of this gene. It is worthy of note that EGFR mutations and the AXL polymorphism rs6508974 independently contributed to the effectiveness of gefitinib, and the polymorphism was proved to be a possible biomarker for selecting non-responders and responders to gefitinib treatment even in the absence of EGFR mutations. Furthermore, this SNP increased the transcriptional activity of the AXL transcript variant 3, one of the three AXL transcript variants, which to some extent increased the epithelial-mesenchymal transition in cancer cells. Taken together, AXL is one of the genes that determine the effectiveness of gefitinib and a biomarker for selecting non-responders and responders among lung adenocarcinoma patients with no EGFR mutations, suggesting that rs6508974 in AXL might be a functional SNP in lung denocarcinoma

Baastrup's Disease Is Associated with Recurrent of Sciatica after Posterior Lumbar Spinal Decompressions Utilizing Floating Spinous Process Procedures

Study DesignRetrospective case-control study.PurposeTo determine whether kissing spine is a risk factor for recurrence of sciatica after lumbar posterior decompression using a spinous process floating approach.Overview of LiteratureKissing spine is defined by apposition and sclerotic change of the facing spinous processes as shown in X-ray images, and is often accompanied by marked disc degeneration and decrement of disc height. If kissing spine significantly contributes to weight bearing and the stability of the lumbar spine, trauma to the spinous process might induce a breakdown of lumbar spine stability after posterior decompression surgery in cases of kissing spine.MethodsThe present study included 161 patients who had undergone posterior decompression surgery for lumbar canal stenosis using a spinous process floating approaches. We defined recurrence of sciatica as that resolved after initial surgery and then recurred. Kissing spine was defined as sclerotic change and the apposition of the spinous process in a plain radiogram. Preoperative foraminal stenosis was determined by the decrease of perineural fat intensity detected by parasagittal T1-weighted magnetic resonance imaging. Preoperative percentage slip, segmental range of motion, and segmental scoliosis were analyzed in preoperative radiographs. Univariate analysis followed by stepwise logistic regression analysis determined factors independently associated with recurrence of sciatica.ResultsStepwise logistic regression revealed kissing spine (p=0.024; odds ratio, 3.80) and foraminal stenosis (p<0.01; odds ratio, 17.89) as independent risk factors for the recurrence of sciatica after posterior lumbar spinal decompression with spinous process floating procedures for lumbar spinal canal stenosis.ConclusionsWhen a patient shows kissing spine and concomitant subclinical foraminal stenosis at the affected level, we should sufficiently discuss the selection of an appropriate surgical procedure

Baastrup\u27s Disease Is Associated with Recurrent of Sciatica after Posterior Lumbar Spinal Decompressions Utilizing Floating Spinous Process Procedures

Study DesignRetrospective case-control study.PurposeTo determine whether kissing spine is a risk factor for recurrence of sciatica after lumbar posterior decompression using a spinous process floating approach.Overview of LiteratureKissing spine is defined by apposition and sclerotic change of the facing spinous processes as shown in X-ray images, and is often accompanied by marked disc degeneration and decrement of disc height. If kissing spine significantly contributes to weight bearing and the stability of the lumbar spine, trauma to the spinous process might induce a breakdown of lumbar spine stability after posterior decompression surgery in cases of kissing spine.MethodsThe present study included 161 patients who had undergone posterior decompression surgery for lumbar canal stenosis using a spinous process floating approaches. We defined recurrence of sciatica as that resolved after initial surgery and then recurred. Kissing spine was defined as sclerotic change and the apposition of the spinous process in a plain radiogram. Preoperative foraminal stenosis was determined by the decrease of perineural fat intensity detected by parasagittal T1-weighted magnetic resonance imaging. Preoperative percentage slip, segmental range of motion, and segmental scoliosis were analyzed in preoperative radiographs. Univariate analysis followed by stepwise logistic regression analysis determined factors independently associated with recurrence of sciatica.ResultsStepwise logistic regression revealed kissing spine (p=0.024; odds ratio, 3.80) and foraminal stenosis (p<0.01; odds ratio, 17.89) as independent risk factors for the recurrence of sciatica after posterior lumbar spinal decompression with spinous process floating procedures for lumbar spinal canal stenosis.ConclusionsWhen a patient shows kissing spine and concomitant subclinical foraminal stenosis at the affected level, we should sufficiently discuss the selection of an appropriate surgical procedure

Spatial distribution and risk factors of Schistosoma haematobium and hookworm infections among schoolchildren in Kwale, Kenya

Background: Large-scale schistosomiasis control programs are implemented in regions with diverse social and economic environments. A key epidemiological feature of schistosomiasis is its small-scale heterogeneity. Locally profiling disease dynamics including risk factors associated with its transmission is essential for designing appropriate control programs. To determine spatial distribution of schistosomiasis and its drivers, we examined schoolchildren in Kwale, Kenya. Methodology/Principal findings: We conducted a cross-sectional study of 368 schoolchildren from six primary schools. Soil-transmitted helminths and Schistosoma mansoni eggs in stool were evaluated by the Kato-Katz method. We measured the intensity of Schistosoma haematobium infection by urine filtration. The geometrical mean intensity of S. haematobium was 3.1 eggs/10 ml urine (school range, 1.4?9.2). The hookworm geometric mean intensity was 3.2 eggs/g feces (school range, 0?17.4). Heterogeneity in the intensity of S. haematobium and hookworm infections was evident in the study area. To identify factors associated with the intensity of helminth infections, we utilized negative binomial generalized linear mixed models. The intensity of S. haematobium infection was associated with religion and socioeconomic status (SES), while that of hookworm infection was related to SES, sex, distance to river and history of anthelmintic treatment. Conclusions/Significance: Both S. haematobium and hookworm infections showed micro-geographical heterogeneities in this Kwale community. To confirm and explain our observation of high S. haematobium risk among Muslims, further extensive investigations are necessary. The observed small scale clustering of the S. haematobium and hookworm infections might imply less uniform strategies even at finer scale for efficient utilization of limited resources

Human Fibroblast Sheet Promotes Human Pancreatic Islet Survival and Function In Vitro

In previous work, we engineered functional cell sheets using bone marrow-derived mesenchymal stem cells (BM-MSCs) to promote islet graft survival. In the present study, we hypothesized that a cell sheet using dermal fibroblasts could be an alternative to MSCs, and then we aimed to evaluate the effects of this cell sheet on the functional viability of human islets. Fibroblast sheets were fabricated using temperature-responsive culture dishes. Human islets were seeded onto fibroblast sheets. The efficacy of the fibroblast sheets was evaluated by dividing islets into three groups: the islets-alone group, the coculture with fibroblasts group, and the islet culture on fibroblast sheet group. The ultrastructure of the islets cultured on each fibroblast sheet was examined by electron microscopy. The fibroblast sheet expression of fibronectin (as a component of the extracellular matrix) was quantified by Western blotting. After 3 days of culture, islet viabilities were 70.2 ± 9.8%, 87.4 ± 5.8%, and 88.6 ± 4.5%, and survival rates were 60.3 ± 6.8%, 65.3 ± 3.0%, and 75.8 ± 5.6%, respectively. Insulin secretions in response to high-glucose stimulation were 5.1 ± 1.6, 9.4 ± 3.8, and 23.5 ± 12.4 μIU/islet, and interleukin-6 (IL-6) secretions were 3.0 ± 0.7, 5.1 ± 1.2, and 7.3 ± 1.0 ng/day, respectively. Islets were found to incorporate into the fibroblast sheets while maintaining a three-dimensional structure and well-preserved extracellular matrix. The fibroblast sheets exhibited a higher expression of fibronectin compared to fibroblasts alone. In conclusion, human dermal fibroblast sheets fabricated by tissue-engineering techniques could provide an optimal substrate for human islets, as a source of cytokines and extracellular matrix